U.S. patent application number 10/026815 was filed with the patent office on 2002-07-18 for energy-efficient running aid.
Invention is credited to Hogan, Bartholomew P., Rennex, Brain G..
Application Number | 20020094919 10/026815 |
Document ID | / |
Family ID | 24489333 |
Filed Date | 2002-07-18 |
United States Patent
Application |
20020094919 |
Kind Code |
A1 |
Rennex, Brain G. ; et
al. |
July 18, 2002 |
Energy-efficient running aid
Abstract
This invention, referred to as an Energy-Efficient Running Aid,
relates to passive (spring-actuated) running/walking aids for
ortheses, prostheses, and robots--to allow faster running using
less energy. The full invention is an leg ortheses or an
energy-efficient running brace. It is a running brace which acts in
parallel with a runner's leg to support the runner during stance
phase and to capture all foot-impact energy, preferably with the
optimal constant-force curve, for use to thrust said runner back
into the air during toe-off. Novel structural elements include a
hyper-extending knee-lock, a variable-angle knee-lock, a kneeless
adjustable-length brace, a self-guiding/constant force bow spring,
a pulley-based/constant-force bow spring, a asymmetric brace foot,
a load-tightening full harness, and a means to guarantee lock
release at toe-off. The running brace eliminates impact injuries by
absorbing the impact energy.
Inventors: |
Rennex, Brain G.;
(Gaithersburg, MD) ; Hogan, Bartholomew P.;
(US) |
Correspondence
Address: |
Brain Rennex
431 Muddy Branch Road, #101
Gaithersburg
MD
20878
US
|
Family ID: |
24489333 |
Appl. No.: |
10/026815 |
Filed: |
December 27, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10026815 |
Dec 27, 2001 |
|
|
|
09621238 |
Jul 26, 2000 |
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Current U.S.
Class: |
482/124 ;
482/74 |
Current CPC
Class: |
A61H 3/008 20130101;
A61F 5/0102 20130101; A61H 2201/0192 20130101; A61H 2201/1652
20130101; A61H 2201/1676 20130101; A63B 25/10 20130101; A61H
2201/0165 20130101; A61H 2201/1642 20130101; A61H 2201/165
20130101; A61H 2201/163 20130101; A61H 2201/1253 20130101; A61H
2201/1621 20130101; A63B 25/00 20130101; A61H 3/00 20130101 |
Class at
Publication: |
482/124 ;
482/74 |
International
Class: |
A63B 021/02; A63B
071/00 |
Claims
1. A running aid comprising a harness attached to a runner's body,
one or more brace legs extending from said harness to the ground,
wherein said brace leg supports a runner's weight while walking and
running, wherein the runner can be a human or a robot, one or more
hip pivots for rotatable connection of said harness with said brace
leg, and one or more asymmetric-travel brace feet, called brace
feet herein, attached to the bottom of said brace leg, wherein said
brace foot is sufficiently long to provide the comparable brace
length asymmetry to said running brace as pertains to the length
asymmetry of said runner, wherein the distance between the hip
joint and the heel of said runner at the beginning of heel strike
is less than the distance between the hip joint and the toe of said
runner at toe-off when his foot leaves the ground, and one or more
foot couplings for attaching said runner's foot with said brace
foot, wherein said running aid must be shaped and positioned so as
to not interfere with the running action of said runner, wherein
tile elements of said running aid must extend around said runner's
leg and foot.
2. The running aid of claim 1 wherein said brace leg comprises a
spring mechanism for storage and return of running impact energy
and a guide to resist the non-axial load of the impact force of
said runner on said spring mechanism, wherein said spring mechanism
connects in series with an upper pylon and a lower pylon of said
brace leg.
3. The running aid of claim 2 wherein said spring mechanism
comprises a series buckling-bow spring further comprising: a top
bow holder, a bottom bow holder, one or more mini-bows hingeably
interconnecting said top bowholder to said bottom bowholder,
wherein said top bow holder and said bottom bow holder make a rigid
series connection with said upper pylon and said lower pylon,
wherein said mini-bows are confined by said top and bottom bow
holders so as to resist in parallel the compression of said top and
bottom bow holders together, wherein said mini-bows are almost
straight when not compressed to provide a buckling force curve when
loaded, in which case their force curve is approximately a buckling
load curve and is approximately constant as said mini-bows deflect
under compression.
4. The running aid of claim 2 wherein said spring mechanism
comprises a perpendicular-series buckling-bow spring further
comprising: a top bow holder, a bottom bow holder, one or more bow
stacks each comprising one or more mini-bows aligned parallel to
each other, wherein at least one pair of said bow stacks is
oriented substantially orthogonal to at least one other said bow
stack, wherein said top bow holder and said bottom bow holder make
a rigid series connection with said upper pylon and said lower
pylon, wherein said mini-bows are confined by said top and bottom
bow holders so as to resist in parallel the compression of said top
and bottom bow holders, wherein said mini-bows hingeably connect
said top bowholder to said bottom bowholder, wherein said mini-bows
are almost straight when not compressed to provide a buckling force
curve when loaded, in which case their force curve is approximately
a buckling load curve and is approximately constant as said
mini-bows deflect under compression, wherein orthogonal orientation
of one said bow stack with another provides a resistance to torque
accompanying non-axial loading of said perpendicular buckling-bow
spring and resultant tilting of said upper pylon with respect to
said lower pylon, wherein said perpendicular buckling-bow spring
also functions as said guide.
5. The running aid of claim 2 wherein said guide comprises a hip
link rotatably connected to said hip pivot and a thigh link element
slidingly connected with said hip link and rotatably connected with
said knee pivot, wherein said spring mechanism comprises a pulley
bucky-bow spring comprising: a bow spring, a bow pulley block, a
bow guide rigidly attached to said bow pulley block and slidingly
connected to the center region of said bow spring, a bow pulley
system comprising one or more pulleys, bow strings which are
connected to either end of said bow spring and which pass around
one or more pulleys in said pulley system, a draw string catch, and
a draw string which is attached at one end to said draw string
catch and which passes around one or more pulleys in said pulley
system and which transmits the force of said bow spring to resist
the sliding of said hip link with respect to said thigh link
element, wherein said bow strings extend from either end of said
bow spring inward toward each other and then around said pulley
system so that the turning of one or more pulleys in said pulley
system causes the ends of said bow spring to be pulled together,
wherein said bow guide prevents said bow spring from rotating
around said pulley block in the sense that an imaginary line
connecting said bow ends does not rotate about said pulley block,
wherein said bow spring may be almost straight when uncompressed to
provide a buckling force curve when loaded, in which case the force
curve is approximately constant as said bow spring is
compressed.
6. The running aid of claim 5 wherein said pulley system comprises
an inner pulley and an outer pulley for creating a mechanical
advantage between the relative travel of said bow strings and said
draw string, wherein the compression and force of said brace leg
can be varied for a given compression of said bow spring.
7. The running aid of claim 6 wherein said harness further
comprises a hip rim encircling said runner and a back support
extending up and behind said runner's back, wherein said bow pulley
block is rigidly attached to said back support, wherein said pulley
system allows a single said bow spring to support one or both said
brace legs during foot stance, wherein said pulley system further
comprises a transfer system of pulleys to route said draw string
from said bow pulley block to engage both of said thigh link
elements at foot strike.
8. The running aid of claim 2 wherein said spring mechanism
comprises a constant-force gas spring which comprises: a gas
spring, gas tubes, a gas reservoir connected to said gas spring by
said gas tubes, and a check valve, wherein the gas in said gas
spring and said gas reservoir is pre-pressurized, wherein the ratio
of volume of gas in said reservoir to volume in said gas spring is
sufficiently high so that the pressure in said gas spring does not
change substantially as said gas spring is compressed, wherein the
force curve of said constant-force gas spring is substantially
constant over its range of compression.
9. The running aid of claim 8 wherein said constant-force spring
system further comprises a gas pump for replenishing pressurized
gas in said gas spring lost during strokes of said gas spring.
10. The running aid of claim 2 wherein said brace leg comprises an
active power source which acts in series with said spring system to
impart thrust to said runner, wherein the force imparted by said
active power source compresses said spring system which then
thrusts with the combined energy from said active power source and
impact energy stored in said spring system during impact of said
runner's foot with the ground.
11. The running aid of claim 1 wherein said brace leg comprises a
swing-phase length-change means to shorten the length of said brace
leg during swing phase and a length-change lock to prevent any
change of the length of said brace leg during stance.
12. The running aid of claim 11 wherein said length-change lock
comprises a means for guaranteed release of said length-change lock
at toe-off.
13. The running aid of claim 12 wherein said swing-phase
length-change means comprises a thigh-link rotatably coupled with
said harness, a knee pivot rotatably attached to said thigh-link
and which further comprises a knee pivot lock corresponding to said
length-change lock, a tibia link rotatably attached to said knee
pivot, wherein the engagement of said pivot lock prevents said
tibia link from rotating about said knee pivot with respect to said
thigh-link assembly during the foot-stance phase portion of a
stride cycle, wherein the disengagement of said pivot lock allows
said tibia link to rotate freely about said knee pivot with respect
to said thigh-link assembly during the swing phase portion of a
stride cycle, wherein said tibia link is rotatably attached to said
brace foot.
14. The running aid of claim 13 wherein said knee pivot lock
comprises a hyper-extended knee lock which further comprises: a
knee pivot block, a thigh-link constraint at the bottom end of said
thigh link, and a tibia-link constraint at the top end of said
tibia link, wherein said thigh-link constraint impinges against
said tibia link constraint during the foot stance period when said
brace foot is in contact with the ground, thereby ensuring that the
structural support comprising said thigh link, said knee pivot lock
and said tibia link is rigid, wherein said rigid state is called
hyper-extension.
15. The running aid of claim 14 wherein said wherein said means for
guaranteed release and said foot coupling comprise a heel pivot
rotatably attached to the back of the foot of said runner and to
the bottom of said tibia link, wherein the rearward location of
said heel pivot ensures that said tibia link and said thigh link
rotate freely so as to move said thigh link constraint away from
said tibia link constraint when the foot of said runner lifts said
heel pivot.
16. The running aid of claim 14 wherein said means for guaranteed
release comprises a knee tether connecting said knee pivot with the
knee of said runner.
17. The running aid of claim 14 wherein said tibia link comprises a
four-bar foot-lift assembly comprising: a thigh-link extension
rigidly extending downward from said thigh link, a foot-lift link
hingeably connected to said thigh-link extension, a toe pivot at
the front of said brace foot wherein said foot-lift link is
hingeably connect to said brace foot via said toe pivot, an ankle
pivot located at the ankle of said brace foot, a
thigh-link-extension front constraint rigidly attached to and
extending forward from the bottom of said thigh-link extension, a
foot-lift-link front constraint rigidly attached to and extending
forward from the top of said foot-lift link, wherein said
thigh-link-extension front constraint impinges said foot-lift-link
front constraint to limit the hyper-extension of said foot-lift
link with respect to said thigh-link extension at heel-down,
wherein the rearward location of said heel pivot ensures that said
foot-lift link and said thigh-link extension rotate freely so as to
move said thigh-link-extension front constraint away from said
foot-lift-link front constraint at toe-off, wherein said foot-lift
link lifts the front of said brace foot via said front pivot during
swing phase thereby preventing downward motion of the front of said
brace foot during swing phase.
18. The running aid of claim 14 wherein said hyper-extended knee
lock comprises a four-bar knee joint which comprises four bars
hingeably interconnected and one side of which is fixably attached
to one said bar and another side of which is fixably attached to
another said bar.
19. The running aid of claim 14 wherein said hyper-extended knee
lock comprises a hyperlocker to ensure hyper-extension before foot
strike.
20. The running aid of claim 19 wherein said knee pivot self lock
comprises a knee-lock hyper-extension means called a hyperlocker,
wherein said hyperlocker accelerates the extension unfolding of
said thigh link and said tibia link about said knee pivot to ensure
that said knee pivot self lock is hyper-extended at heel-strike,
wherein said hyperlocker comprises a rim beam pulley rigidly
attached to said harness, a thigh-link pulley attached to said
thigh-fink, a slide-pulley cord attached to said rim beam, wherein
the forward swinging of said thigh link causes the upward pulling
on said slide-pulley cord through said thigh-link pulley, a
hyper-extension means keyed to the upward pull on said slide-pulley
cord, wherein said tibia link is forced to hyper-extend about said
knee pivot (with respect to said thigh link) during the latter part
of swing phase, wherein said tibia link can be freely folded by the
upward force of said runner's foot on said brace foot at
toe-off.
21. The running aid of claim 19 wherein said hyperlocker comprises
a self-hyperlocker further comprising a closer cord, a cord-path
system which routes said closer cord through a path along both the
back side and the front side of said thigh and tibia links about
said knee pivot, wherein said closer cord is fixed at a first end
to said brace leg, wherein the cord-path length on the back side of
said knee pivot increases more rapidly than the cord-path length on
the front side of said knee pivot during said extension unfolding,
a closing spring located on the front side of said brace leg so as
to pull into hyper-extension said thigh and tibia links when
engaged, a spring release connected to said brace leg and to a
second end of said closer cord, and a pawl system, wherein the
configuration of said cord-path system causes said closer cord to
pull taut at a particular flexion angle, of said thigh link with
respect to said tibia link, as said brace leg extends during swing
phase--causing said closer cord to pull against said closing spring
accelerating said extension unfolding, wherein said spring release
is triggered to release said closing spring from acting against
said closer cord as hyper-extension occurs, thereby allowing easy
and force-free folding of said tibia link with respect to said
thigh link at toe-off, and a reset spring for re-engaging said
closer cord with said closing spring during swing phase when said
closer cord becomes slack, wherein said self hyperlocker is keyed
to said flexion angle for guaranteed hyper-extension using said
closing spring, and it is keyed to said hyper-extension for
guaranteed release of said closing spring as folding begins.
22. The running aid of claim 14 wherein said knee pivot lock
further comprises a "hyper-extension bounce back" prevention means
to prevent the impact force of the closing of said knee pivot from
causing said brace leg to bounce back out of hyper-extension
wherein said "hyper-extension bounce back" prevention means also
comprises a bladder step, in the impinging surface of said tibia
link that contacts said thigh link during said hyper-extension,
wherein said bladder step forms a recessed region between said
impinging surface and said thigh link when they are aligned, a
pinched bladder attached to said bladder step, filled with fluid,
and protruding above the level said impinging surface, a pinch
band, and an elastomer nipple, wherein said pinched band constricts
said pinched bladder to form said elastomer nipple and to form an
orifice between said elastomer nipple and said pinched bladder,
wherein said elastomer nipple lies outside of said bladder step,
wherein said fluid is free to flow through said orifice from said
pinched bladder to said elastomer when said hyper-extension
occurs--and during swing phase, wherein the restricted flow of said
fluid through said orifice dissipates said impact force of
closing.
23. The running aid of claim 12 wherein said knee pivot lock
comprises a variable-angle knee lock comprising: a shaft, shaft
spacers, a shaft boss rigidly attached to and subtending a shaft
locking angular range of said shaft, wherein said shaft boss
further comprises a plurality of shaft circumferential strips
rigidly attached to said shaft boss by a boss attachment structure,
wherein said shaft circumferential strips are spaced apart one from
another by said shaft spacers, wherein said shaft circumferential
strips extend in the shaft longitudinal direction from their
attachment location, collar spacers, a split-collar encircling said
locking shaft wherein said split-collar further comprises a bearing
collar section and a locking collar section, wherein said locking
collar section further comprises a plurality of collar
circumferential strips rigidly attached to said locking collar
section by a collar attachment structure, wherein said collar
circumferential strips are spaced apart one from another by said
collar spacers, wherein said collar circumferential strips extend
in the shaft longitudinal direction from their attachment location,
wherein said bearing collar section forms a bearing surface with
the portion of said shaft not subtended by said shaft locking
angular range thereby allowing free pivoting of said split-collar
about said shaft when said bearing surface is loaded, wherein said
locking collar section subtends a collar locking angular range,
wherein said shaft circumferential strips interleaf with said
collar circumferential strips over an overlap longitudinal region,
wherein said locking collar section has a collar recess for
allowing said locking collar section to freely impinge said collar
circumferential strips and said bearing circumferential strips at
said longitudinal region without constraint by said boss attachment
structure, wherein the radial extent of the inner portion of said
shaft boss is sufficient to allow said locking collar section to
freely impinge said collar circumferential strips and said bearing
circumferential strips at said overlap longitudinal region without
constraint by said collar attachment structure, wherein said
locking collar section forms a locking surface with the portion of
said shaft subtended by said shaft locking angular range thereby
ensuring locking of rotation of said split-collar about said shaft
when said locking surface is loaded.
24. The running aid of claim 23 wherein said tibia link comprises
an upper-tibia link hingeably connected to said knee pivot, a
lower-tibia link hingeably connected with said ankle pivot, a tibia
pivot for hingeably connecting said upper-tibia link with said
lower-tibia link, a lower-tibia-link front constraint rigidly
attached to and extending forward from the top of said lower-tibia
link, an upper-tibia-link front constraint rigidly attached to and
extending forward from the bottom of said upper-tibia link, wherein
said upper-tibia-link front constraint impinges said
lower-tibia-link front constraint to limit the hyper-extension of
said lower-tibia link with respect to said upper-tibia link at
heel-down, wherein the rearward location of said heel pivot ensures
that said tibia link and said thigh link rotate freely so as to
move said lower-tibia-link front constraint away from said
upper-tibia-link front constraint at toe-off, wherein any residual
loading of said variable-angle knee lock at toe-off is released due
to the folding of said upper-tibia link with respect to said
lower-tibia link, a lower-tibia-link rear constraint rigidly
attached to and extending backward from the top of said lower-tibia
link, an upper-tibia-link rear constraint rigidly attached to and
extending rearward from the bottom of said tipper-tibia link,
wherein said tipper-tibia-link rear constraint impinges said
lower-tibia-link front constraint to limit the folding of said
lower-tibia link with respect to said tipper-tibia link during
swing phase, and a closing mechanism to ensure that said
lower-tibia-link front constraint impinges against said
upper-tibia-link front constraint at heel-down, thereby ensuring
that the structural support comprising said upper-thigh link, said
tibia pivot and said lower-tibia link is rigid during stance
phase.
25. The running aid of claim 12 wherein said swing-phase
length-change means comprises a lockable slider comprising a guide
means comprising an upper and lower guide slidably interconnected,
wherein said guide means is a series component of said brace leg, a
slider lock corresponding to said length-change lock, and a
slider-lock trigger, wherein ground contact of said brace foot
causes said slider lock to lock said lockable slider, wherein said
lockable slider is a series component of either said thigh link or
said tibia link.
26. The running aid of claim 25 wherein said knee pivot lock
comprises a lockable hydraulic slider comprising one or more
hydraulic cylinders containing fluid and a fluid line, one or more
hydraulic pistons which slide within said hydraulic cylinders
moving said fluid through said fluid line, a reservoir connecting
said fluid line to said reservoir via an exit branch and a return
branch, a triggered valve system which prevents or restricts said
fluid from exiting said hydraulic cylinder during stance, thereby
locking said lockable hydraulic slider, and which allows said fluid
to freely exit and enter said hydraulic cylinder during swing
phase, thereby allowing free compression and expansion of said
lockable hydraulic slider, wherein said lockable hydraulic slider
is rotatably attached to both thigh link and said tibia link,
wherein the locking of said lockable hydraulic slider locks said
knee pivot lock.
27. The running aid of claim 25 wherein said lockable slider
comprises a lockable hydraulic slider comprising one or more
hydraulic cylinders containing fluid and a fluid line, one or more
hydraulic pistons which slide within said hydraulic cylinders
moving said fluid through said fluid line, a reservoir connecting
said fluid line to said reservoir via an exit branch and a return
branch, a triggered valve system which prevents or restricts said
fluid from exiting said hydraulic cylinder during stance, thereby
locking said lockable hydraulic slider, and which allows said fluid
to freely exit and enter said hydraulic cylinder during swing
phase, thereby allowing free compression and expansion of said
lockable hydraulic slider.
28. The running aid of claim 12 wherein said swing-phase
length-change means comprises a lockable slider comprising a guide
means comprising an upper and lower guide slidably interconnected,
wherein said guide means is a series component of said brace leg, a
slider lock corresponding to said length-change lock, and a
slider-lock trigger, wherein ground contact of said brace foot
causes said slider lock to lock said lockable slider.
29. The running aid of claim 28 wherein said lockable slider
comprises a lockable hydraulic slider comprising one or more
hydraulic cylinders containing fluid and a fluid line, one or more
hydraulic pistons which slide within said hydraulic cylinders
moving said fluid through said fluid line, a reservoir connecting
said fluid line to said reservoir via an exit branch and a return
branch, a triggered valve system which prevents or restricts said
fluid from exiting said hydraulic cylinder during stance, thereby
locking said lockable hydraulic slider, and which allows said fluid
to freely exit and enter said hydraulic cylinder during swing
phase, thereby allowing free compression and expansion of said
lockable hydraulic slider.
30. The running aid of claim 1 wherein said brace leg comprises a
front/back brace leg further comprising a front hip pivot, p1 a
back hip pivot, a front thigh link pivotly attached to the front of
said harness with said front hip pivot, a back thigh link pivotly
attached to the front of said harness with said back hip pivot, an
optional front bow attached to said front thigh link, a optional
back bow attached to said back thigh link, a front tibia link
pivotly attached to the front of said brace foot, a back tibia link
pivotly attached to the back of said brace foot, a front knee pivot
connecting said front thigh link and said front tibia link, a back
knee pivot connecting said back thigh link and said back tibia
link, one or more hyper-extending knee pivot locks at the locations
of said front and back knee pivots to prevent pivot
hyper-extension, an optional back hydraulic knee lock pivotly
attached to said back thigh link and said back tibia link, an
optional front hydraulic knee lock pivotly attached to said front
thigh link and said front tibia link, a front ankle pivot for the
connection of said front tibia link to said brace foot, a back
ankle pivot for the connection of said back tibia link to said
brace foot, a knee cross link connecting said front knee pivot with
said back knee pivot, wherein said front and back hip pivots are
located approximately above the center of each leg, wherein the
front and back locations of said brace leg elements prevents
interference with said runner's legs.
31. The running brace of claim 30 wherein said harness comprises a
front/back pack extension further comprising a front pack-frame
pivot at the front of said harness, a back pack-frame pivot at the
back of said harness, a front pack frame attached to the front of
said harness via said front pack-frame pivot, a back pack frame
attached to the back of said harness via said back pack-frame
pivot, pack straps, a front pack secured to said front pack frame
be said pack straps, and back pack secured to said back pack frame
be said pack straps, wherein said brace legs continuously support
said front and back packs as said runner walks or runs.
32. The running aid of claim 1 wherein said brace foot comprises a
curved surface on the bottom of said brace foot.
33. The running aid of claim wherein said brace foot comprises one
or more lockable hinged extensions in the front or back of said
brace foot which can be locked for running or walking on relatively
flat or shallow sloping terrain and which can be retracted for
running or walking on steps or steep terrain.
34. The running aid of claim 28 wherein said slider-lock trigger
comprises an array of ground levers rotatably attached along the
bottom of said brace foot, a ground pulley, and a ground trigger
cord fixably interconnecting each said ground lever with its
neighbor and passing around said ground pulley and up to said
slider lock, wherein ground contact of any one of said ground
levers causes said ground pulley to engage said slider lock.
35. The running aid of claim 12 wherein said means for guaranteed
release comprises a foot-coupling guaranteed release which allows a
runner's foot to freely move up at toe-off without lifting said
brace foot for a prescribed time and distance and which ensures
that said brace foot is lifted that same distance with respect to
said runner's foot during swing phase, wherein any force between
said runner's foot and said brace foot is zero for said prescribed
time--allowing said length-change lock to release, wherein said
brace foot is not allowed to hang below said runner's foot and trip
said runner as said brace foot approaches heel-strike.
36. The energy-efficient running brace of claim 1 wherein said
harness comprises: a plurality of harness sections wherein some
harness sections are upward-pull sections which naturally support
an upward pull and some sections are downward-pull sections which
naturally support a downward pull, vertical connectors between said
upward-pull sections and said downward-pull sections, and p1 a
vertical tightening mechanism for cinching said upward-pull
sections and said downward-pull sections against each other via
said vertical connectors, wherein the compliance between said
harness and said runner is reduced.
37. The running aid of claim 1 wherein said harness comprises a
load-tightening mechanism to grip more tightly the body parts of a
runner as the brace load of her weight between said support system
and said harness increases, wherein the increased gripping force of
the harness on said body parts is provided by said brace load,
wherein a tightening distance is associated with said gripping and
said tightening distance is the decrease in circumferential length
of said harness due to said gripping.
38. The running aid of claim 37 wherein said load-tightening
mechanism comprises one or more load-tightening cuffs encircling
said body parts and a tightening mechanism to re-direct said brace
load from an approximate vertical direction to an approximate
horizontal direction to accomplish said gripping force to tighten
said load-tightening cuffs.
39. The running aid of claim 37 wherein said load-tightening
mechanism comprises a compressible woven harness, wherein said
brace load pulls upward on the upper portion of said compressible
woven harness causing said compressible woven harness to shrink in
size, thereby increasing said gripping force, wherein said
compressible woven harness comprises braids interwoven among
themselves and extending along and around said body parts.
40. The running aid of claim 37 wherein said load-tightening
mechanism comprises a mechanical-advantage mechanism wherein the
distance or travel of the connection point between said brace leg
and said harness is multiplied by a mechanical advantage to yield a
greater value for said tightening distance, wherein the compliance
between said brace leg and said harness under load is reduced by a
factor approximately equal to said mechanical advantage.
41. The running aid of claim 1 wherein said harness comprises an
arm-load harness to partially support said brace load with the arms
of said runner.
42. The running aid of claim 1 wherein said harness comprises a
load-equalizer means to distribute said brace load over all
portions of said harness, wherein said load-equalizer means further
comprises a system of pulleys and cables to evenly distribute said
brace load over all portions of said harness.
43. The running aid of claim 1 wherein said harness comprises
adjustable bands and fitting clamps wherein said adjustable bands
are pulled through said fitting clamps and clamped to snugly fit
said harness to said body parts.
44. The running aid of claim 38 wherein said tightening mechanism
comprises: a spreader bar, cuff buckles, one or more tightening
pulleys, tightening cords, and stay cords, wherein said
load-tightening cuffs are attached on either end to said cuff
buckles, wherein said spreader bar is mounted to said
load-tightening cuff near an end, wherein said tightening pulleys
are mounted to said spreader bar, wherein said stay cords are
connected to said brace leg and transmit said brace load to tighten
said tightening cuff by passing around said tightening pulleys
which re-direct said brace load direction from a vertical to a
horizontal direction, wherein said tightening cords also pass
around said tightening pulleys and attach to said cuff buckles to
transmit said brace load to pull together the ends of said
tightening cuff, thereby tightening said tightening cuff.
45. The running aid of claim 25 wherein said tightening mechanism
comprises: a spreader bar, cuff buckles, one or more tightening
levers, tightening cords, and stay cords, wherein said
load-tightening cuffs are attached on either end to said cuff
buckles, wherein said spreader bar is mounted to said
load-tightening cuff near an end, wherein said tightening levers
are mounted to said spreader bar, wherein said stay cords are
connected to said brace leg and transmit said brace load to tighten
said tightening cuff by pulling on first ends of said tightening
levers to re-direct said brace load direction from a vertical to a
horizontal direction, wherein said tightening cords are connected
both to second ends of said tightening levers and also to said cuff
buckles--to transmit said brace load to pull together the ends of
said tightening cuff, thereby tightening said tightening cuff.
46. The running aid of claim 39 wherein said compressible woven
harness comprises combination mechanical/weave load-tightener
comprising: stay cords, pulley block attached to stay cords, one or
more block pulleys mounted on said pulley block, top hoop sliding
mounted to the top of said compressible woven harness, bottom hoop
sliding mounted to the bottom of said compressible woven harness,
vertical spreader bar mounted to said top hoop, one or more
spreader pulleys mounted to the bottom of said vertical spreader
bar, and cables, wherein said vertical spreader bar pulls upward on
said compressible woven harness via said top hoop, wherein this
upward pull is exerted by said cables which pass from said vertical
spreader bar around said block pulleys and then down to pass around
said spreader pulleys to pull down on bottom hoop, thereby
spreading said compressible woven harness and causing it to
circumferentially contract and grip said body parts.
Description
[0001] This application is a continuation in parts of application
Ser. No. 09/621,238 filed on Jul. 26, 2000 by Brian Rennex.
BACKGROUND OF THE INVENTION
[0002] This invention, referred to as a running aid, relates to
running braces and in particular to energy-efficient running
braces. A running brace augments the effective spring constant of
the leg by adding a resilient brace which supports the runner's
weight in parallel with the leg. The invention combines the balance
and control capabilities of the human foot/leg system with the
strength and resilience features of a mechanical brace system.
[0003] Around 1890, four running brace patents were issued to
Nicholas Yagn, a mechanical engineer in the army of the Emperor of
Russia. The first two, U.S. Pat. Nos. 420,178 and 420,179, use bow
springs, attached to the shoulder and the pelvis, respectively. The
second of these incorporates a foot-lift means whereby the top of
the bow spring can slide up a plate extending upwards from the
runner's waist, during swing phase. However, there is no workable
means to trigger this sliding. U.S. Pat. No. 438,830 was based on
an unworkable design to fill a flexible tube with compressed gas to
achieve a resilient brace. The fourth, U.S. Pat. No. 406,328
comprised telescopic springs and an unworkable telescopic release
for leg lift in swing phase.
[0004] More recently, Chareire, U.S. Pat. No. 4,872,665, provides
for a running brace comprising telescoping gas springs and a
leg-lift means further comprising a ratchet joint. In principle,
this invention should, in principle, work but it is exceedingly
complex and it would be difficult and expensive to manufacture. In
addition, it is doubtful that the trigger system for braking and
releasing the rachet joint is versatile. Another drawback of the
design is that compressive telescopic means necessarily entail
friction losses, and this is especially the case with gas springs.
Also, the travel of this running brace is limited by the
requirements of telescopic overlap.
[0005] Dick, U.S. Pat. No. 5,016,869, discloses another complicated
and heavy (50 lbs.) bipedal device which is intended to ensure a
long travel and leg lift in swing phase, and it appears that the
runner's weight is not supported in parallel with the runner's legs
in which case the device is equivalent to a series-support running
shoe and not a running brace. A number of links, cables and springs
are incorporated in the involved design as to make the device
rather cumbersome. Rennex disclosed an invention in U.S. Pat. No.
5,011,136 to provide for asymmetric leg-length travel in impact and
thrust and to provide for high leg lift. It features a pair of
telescopic springs and a trigger and ratchet system to achieve this
asymmetry. The disadvantages of this design are its complexity and
friction losses in the compressive telescopic design. Other
provisions attempted to address the problem of optimized force
curves to achieve high performance and high impact energies without
Injury.
[0006] This inventor was not able to find prior art for harnesses
specifically designed for coupling a running brace to the human
body. One related example is disclosed by Petrofsky in U.S. Pat.
No. 5,054,476, which uses support elements coming up the sides of a
walker with cuffs attached at the thigh, waist , and armpit levels
to give the walker support. This design does not provide for
comfortable support for the brace loads of several gees needed for
a running brace. A second example is disclosed by Spademan in U.S.
Pat. No. 5,002,045, in which cuffs or straps attached to the limbs
(or the waist) on either side of a joint are tightened as the limbs
bend around that joint. The current patent is distinguished from
both of these examples of prior art by virtue of the fact that the
brace load is distributed in an adjustable manner over a
substantial area of the human body for optimal comfort, and the
automatic harness tightening is powered by the impact load on the
brace, and not the relative motions of adjacent human limbs or
elements. These features are adapted for the demanding requirements
of running-brace support where load forces are large--several
gees--and the human body is erect. Virtually all harnesses for high
loads require the user to be sitting, and, hence, they are not
useful for a running brace.
[0007] Regarding the prosthetic applications of the novel,
tibia-located self-guiding springs of this invention, Phillips
discloses in U.S. Pat. No. 5,458,656 a leaf spring guided by
telescoping tubes and hingeably-attached to the top knee pylon. The
drawback of this invention is that the telescoping guide is costly
and the deflection of the single spring is limited. Kania discloses
in U.S. Pat. No. 5,653,768 a pair of leaf springs fixedly attached
to the top knee pylon and passing one through the other. The
limitation of this design is that the spring deflection is limited
because the leaf springs are not hingeably connected. Likewise
Rappoport discloses in U.S. Pat. No. 5,509,936 a pair of leaf
springs fixedly attached to the top knee pylon--with limited
deflection. The advantage of the tibia spring in the current
invention is that the vertical bow springs are hingeably attached,
allowing optimization of the spring system in terms of ample
deflection, constant force-curve, and low weight. Also, cost is
reduced by eliminating the guide system.
SUMMARY OF THE INVENTION
[0008] This "running aid" invention relates to passive
(spring-actuated) running aids for ortheses, prostheses, and
robots. The full invention is an leg ortheses or an
energy-efficient running brace. It is a running brace which acts in
parallel with a runner's leg to support the runner during stance
phase and to capture all foot-impact energy, preferably with the
optimal constant-force curve, for use to thrust said runner back
into the air during toe-off. Moreover, several structural
components of the full invention also have applications for
prostheses, robots, and robotic exoskeletons to enhance human
performance. These structural elements include a novel
variable-angle knee-lock, a novel self-guiding/constant force bow
spring, a novel pulley-based/constant-for- ce bow spring, a novel
brace/ankle system, a novel front/back brace leg which couples to
the runner's pelvis in the front and back of his pelvis, novel
means to ensure hyper-extension for "constrained hyper-extension"
knee locks (referred to as self-locking), a novel and very cheap
means to prevent "bounce-back" with self knee locks, and a novel
load-tightening full harness. In addition to allowing faster
running with less energy, the running brace protects the legs,
joints and feet from impact injury since it eliminates impact
forces above a safe level. The running brace is coupled to the
runner via a body harness. This coupling must be located above the
leg to allow it to rest as much as possible during the stance
phase.
[0009] This running aid provides an essential improvement over
prior art in the following ways. The force curve of the leg spring
is optimal for quick support and maximum energy storage. Tile
problem of a lock--to switch the running brace from a stiff spring
mode during stance to free bending mode during swing phase--is
circumvented with self-locking designs, and it is solved with
either a novel variable-angle knee lock or a slider lock. The
problem of leg-length asymmetry is overcome with a shaped brace
foot, and the comfort problem is addressed with a novel
load-tightening pelvic/body harness which distributes the impact
load over a substantial portion of the body above the knees.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a schematic side view of the running aid generic
to the various embodiments of the invention.
[0011] FIG. 2 shows side views of series bow springs for use in the
first embodiment of the invention.
[0012] FIG. 3 shows side and top views of perpendicular-bow
self-guiding springs for use in the first embodiment of the
invention.
[0013] FIG. 4 shows a side view of a tibia
perpendicular-spring/brace-foot assembly for use in the first
embodiment of the invention.
[0014] FIG. 5 shows side views of a tibia
perpendicular-spring/hinged-brac- e-foot assembly.
[0015] FIG. 6 is a side view of the decoupled-bow version of the
running aid according to the second embodiment of the
invention.
[0016] FIG. 7 is a front view of the decoupled-bow version of the
running aid according to the second embodiment of the
invention.
[0017] FIG. 8 is a side view of the running aid according to the
third embodiment of the invention showing a gas spring with a
reservoir.
[0018] FIG. 9 is a side view of the support part of a self-locking
knee mechanism of the running aid according to the fourth
embodiment of the invention.
[0019] FIG. 10 is a side view of the 4-bar foot-lift assembly for
maintaining clearance of the brace foot above the ground during
swing phase according to the fourth embodiment of the
invention.
[0020] FIG. 11 is a front cross-sectional view of the running aid
according to the fifth embodiment of the invention showing the
variable-angle knee lock.
[0021] FIG. 12 is a side cross-sectional view of the running aid
according to the fifth embodiment of the invention showing the
shaft/collar assembly of the variable-angle knee lock.
[0022] FIG. 13 is a side cross-sectional view of the running aid
according to the fifth embodiment of the invention showing the
shaft and the collar of the variable-angle knee lock.
[0023] FIG. 14 is a side cross-sectional view of the running aid
according to the fifth embodiment of the invention showing rotation
of the shaft with respect to the collar of the variable-angle knee
lock.
[0024] FIG. 15 is a side view of the running aid according to the
fifth embodiment of the invention showing a damper for use with the
variable-angle knee lock.
[0025] FIG. 16 is a side view of the running aid according to the
fifth embodiment of the invention showing a tibia lock-release for
use with the variable-angle knee lock.
[0026] FIG. 17 is a back view of the cable system allowing the use
of a single bow spring in the sixth embodiment of the running
aid.
[0027] FIG. 18 shows schematic views of the full harness for the
running aid.
[0028] FIG. 19 is a side view of a generic mechanical design for a
mechanical load-tightener used in the harness for the running
aid.
[0029] FIG. 20 shows examples of compressible woven harnesses for
load-tightening sleeves of the harness for the running aid.
[0030] FIG. 21 is a side view of an overlap double-pulley load
tightener which is an example of a mechanical load-tightening cuff
used in the harness for the running aid.
[0031] FIG. 22 is a side view of a bent-lever load tightener, a
jamming load tightener and an inward-force load tightener of the
harness for the running aid.
[0032] FIG. 23 is a side view of a combination mechanical/weave
load-tightener of the harness for the running aid.
[0033] FIG. 24 is a side view of an arm load-bearing harness for
the running aid.
[0034] FIG. 25 shows a schematic front view of a load-equalizer
stay tree which distributes the brace load over various parts of
the harness for the running aid.
[0035] FIG. 26 shows an adjustable harness for the running aid.
[0036] FIG. 27 shows a side view of a generic brace leg with a
circular brace foot, demonstrating graphically how well the brace
foot prevents vertical travel of the runner's center of mass
throughout stance.
[0037] FIG. 28 shows a hyperlocker mechanism to guarantee
hyper-extension of the self-locking knee mechanism of the fourth
embodiment of the invention of FIG. 9.
[0038] FIG. 29 shows a slider for changing the length of a running
aid according to the seventh embodiment of the invention.
[0039] FIG. 30 shows a full-stance brace-foot trigger for locking a
slider during stance.
[0040] FIG. 31 shows a foot-coupling guaranteed release mechanism
for release of the slider lock at toe-off.
[0041] FIG. 32 shows a simple-slider running brace according to the
eighth embodiment of the invention, wherein the knee pivot is no
longer used.
[0042] FIG. 33 shows a means to combine an active power source with
a passive spring according to the ninth embodiment of the
invention.
[0043] FIG. 34 shows two lockable hydraulic sliders with two and
three telescopic members.
[0044] FIG. 35 shows a knee pivot locked by a lockable hydraulic
slider according to the eleventh embodiment of the invention.
[0045] FIG. 36 shows a self-hyper-locker for guaranteeing
hyper-extension at foot strike.
[0046] FIG. 37 shows a "hyper-extension bounce back" prevention
means for prevention of folding of a hyper-extending knee lock at
heel strike.
[0047] FIG. 38 shows a front/back brace leg in which the pelvic
coupling is made directly behind and in front of the runner's
ischial tuberosity (buttock) rather on the side of the hip.
[0048] FIG. 39 shows a front/back pack extension for comfortable
and optimal pack load support.
[0049] FIG. 40 shows a four-bar knee joint.
[0050] FIG. 41 is a schematic side view of the bow shoe showing a
low-eccentricity knee-joint straightener.
DESCRIPTION
[0051] FIG. 1 is a schematic side view of running aid 2 with runner
1 shown in dashed lines to indicate the approximate location and
extent of the various elements of the invention with respect to the
runner who wears the invention. Running aid 2 comprises harness 3
and two brace legs 9, one on the outside of each leg of runner 1.
Each brace leg 9 supports runner 1 when her adjacent foot is in
contact with the ground during running, i.e. during the stance
phase, as distinguished from the swing phase when that leg is not
in contact with the ground. Harness 3 is attached to the runner's
pelvis, and each brace-foot assembly 8 is attached to the adjacent
runner's foot. Since running aid 2 supports the weight of runner 1
in parallel with her leg, she can rest her leg during the stance
phase of the running stride cycle. Since running aid 2 can act as a
spring to absorb the impact energy of running and to thrust runner
1 back into the air during leg thrust, runner 1 can both exert less
energy while running and avoid in juries related to the impact of
running. Later, each design component will be discussed in detail,
but, first, here is a quick overview.
[0052] In order to be able to swing a brace leg forward and/or run
uphill, a swing-phase length-change means is required. One option
is knee pivot 6 of FIG. 1; another option is simple-slider running
aid 561 of FIG. 32. In FIG. 1, thigh-link 4 is rotatably attached
to harness 3 on the top and to knee pivot 6 on the bottom. Spring
mechanism 5 is incorporated into thigh-link 4 in the second
embodiment of the invention shown in FIG. 6, but is may be located
elsewhere, e.g., on the back of runner 1 in the sixth embodiment of
FIG. 17 or in the tibia link 7 as an option of the second
embodiment of FIG. 6. Or, there can be no spring at all in this
running aid invention, in which case the running aid simply
provides support and in which case the design features in the
discussion of FIG. 5 are crucial to provide the brace leg/foot
length asymmetry to match the brace support to the runner's leg
action. This "no-spring" variation will be referred to as the tenth
embodiment of the invention. As will be seen in the more detailed
description of the second embodiment in FIG. 6, thigh-link 4
includes a guide means which constrains an element rotatably
connected to harness 3 to slide with respect to an element
connected to knee pivot, under the action of bucky-bow spring
mechanism 10--to deliver an impulse to runner 1. Knee pivot 6
connects thigh-link assembly 4 and tibia link 7, and it
incorporates the brace-link self-locking mechanism to be detailed
later. The bottom of tibia link 7 is attached to brace foot 8 which
contacts the ground. Each of these components has one or more
specific functions essential to easy, efficient running. These
functions will next be previewed in a general sense to prepare the
reader for the more detailed discussion of the drawings.
[0053] Harness 3 must couple running aid 2 to runner 1 above his
leg to ensure that running aid 2 acts in parallel with his leg.
Since the g-force of running can be 2-3 g's, there is significantly
more weight on harness 3 than would be the case with bicycle
riding, for example. Since conventional harnesses actually require
the user to sit, in which case most of the weight is borne by the
backs of the thighs and the back of the waist loop, these
conventional harnesses cannot be used for the running aid harness,
as one cannot run and sit at the same time. Also, conventional,
"above the knee" orthotics, which comprise a rigid, tapered thigh
socket and a lip to receive the weight of the ischial tuberosity at
the base of the buttocks, receive perhaps 40% of the load in the
thigh tapered region. Since the thighs of able-legged runners
change shape due to muscular and tendon activity, these
conventional, thigh-socket orthotics cannot comfortably be used for
running aid 2. Therefore, the design discussion for harness 3
presents a means to spread the brace load over a substantial
portion of the body. The area of harness support indicated in FIG.
1 extends from the lower thigh to the chest, but it may also
include the arms and shoulders.
[0054] Spring mechanism 5 should give runner 1 virtually
instantaneous support. The optimal force curve is achieved with a
bow spring with a buckling force curve in which the force changes
virtually instantaneously to the critical-load value and continues
at close to that value as the bow bends further. In the second
embodiment of the invention of FIGS. 6 and 7, this buckling force
curve is achieved by pulling the bow ends straight together. Since
pulleys are used in this design, it is straightforward to achieve a
mechanical advantage which allows, first, reduced bow flexing--an
important feature since there is a tradeoff between flexibility and
strength--and, second, a de facto changing of gears. Another
advantage of the pulley/cable aspect of spring mechanism 5, which
becomes bucky-bow spring mechanism 10 in FIG. 6, is that it can be
located anywhere, e.g., on the sides of the legs, behind the legs,
or behind the back. Also, a single bucky-bow spring mechanism can
be used for both legs of runner 1. Although a variety of spring
systems, such a helical springs with longitudinal, "piston-like"
guides, may be used in this invention, the bucky-bow has the
distinct advantage of the buckling force curve.
[0055] Knee pivot 6 allows the folding of thigh-link 4 and tibia
link 7. This, in turn, allows runner 1 to high-kick his leg during
swing phase, when the leg is not in ground contact. However, there
must be some way to lock knee pivot 6 during the stance phase, when
the leg is in ground contact. The strength requirements of this
locking are very high due to the leverage about knee pivot 6. And,
since runner 1 may sometimes land on a bent knee, e.g., when
running uphill, this locking must work when thigh link 4 and tibia
link 7 have not yet rotated to be aligned. These lock-design
requirements have been the major design hurdle for running-brace
prior art. The current invention circumvents this locking problem
with a self-locking knee designs of FIGS. 9 and 36, and it solves
it with the variable-angle knee lock of FIGS. 1 1-14 and with the
hydraulic locks of FIGS. 32 and 35.
[0056] The purpose of brace-foot 8 is to give running aid 2 the
same length asymmetry as is the case for the legs of runner 1. The
term length asymmetry refers to the fact that the effective length
of the leg/foot system of runner 1 (e.g., the distance between the
hip pivot and the effective point of contact of her foot with the
ground) is several inches shorter for landing (heel-down) than for
taking off (toe-off). This length asymmetry results from the
presence of the human foot and ankle, and it serves to reduce the
leg/foot angle of heel-down relative to that of toe-off, thereby
improving running energy efficiency. If a running aid does not
feature this same length asymmetry, the timing of brace thrust will
be too early for optimal, efficient brace thrust. The
just-mentioned self-locking requires that brace-foot 8 be rotatably
attached to the runner's foot behind her heel. The drawback then is
that brace-foot 8 may rotate so that its front portion will drop
below the level of the runner's toe, leading to a tripping hazard.
To avoid tripping, the brace foot must have the design of FIG. 10
to lift the front of brace foot 8 during swing phase.
[0057] This completes the overview. Now the detailed components of
the invention will be described. FIG. 2a is a side view showing
guided bow spring 426. This first embodiment utilizes "series" bow
springs which are almost straight when unloaded and which are
loaded by pushing the ends of the bow springs toward each other--to
achieve a buckling or constant spring force curve (versus
deflection). Guided bow spring 426 and spring guide 435 comprise
upper guide 438 which is slidingly corrected to lower guide 436.
Upper guide 438 is rigidly connected to top bowholder 428, and
lower guide 436 is rigidly connected to bottom bowholder 430. One
or more mini-bows 434 are hingeably connected between bottom
bowholder 430 and top bowholder 428. Accordingly, guided bow spring
426 is located in series with thigh link 4 and/or tibia link 7 (see
FIG. 1), and the runner's impact force forces upper guide 438 to
slide down into lower guide 436 and compress mini-bows 434. In like
manner, the design of FIG. 2b is the same as that of FIG. 2a except
that there are two spring guides 435 located on either side of
mini-bows 434.
[0058] FIG. 3 shows top and side views of perpendicular-bow
self-guiding bows 444. FIG. 3a shows a top view and FIG. 3b a side
view of T-shaped perpendicular-bow system 440 in which one or more
mini-bows 434 are oriented perpendicular to one or more other
mini-bows 434. The rationale is to take advantage of the resistance
to bending in the plane of the wide dimension of a bow. In this
case and in general, mini-bows 434 are substantially wider than
they are thick. Since mini-bows 434 are hingeably attached to
end-plates 448 via hinges 14, if only one mini-bow 434 stack (all
parallel to each other) is used, then end-plates 448 can rotate
freely with one degree of freedom. As soon as another single one or
stack of mini-bows 434 is connected between end-plates 448 with an
orthogonal or a substantially orthogonal orientation, each
orthogonal mini-bow 434 resists rotation of the orthogonal
mini-bows 434 in the orthogonal degree of rotational freedom. The
result is that T-shaped perpendicular-bow system 440 resists
tilting of one end-plate 448 with respect to the other on the
opposite end, and this gives a substantially self-guiding spring
system. As mini-bows 434 bow over considerably, this self-guiding,
or ability to resist non-axial loads is compromised, but in some
applications it eliminates the need for a guide system longitudinal
to the perpendicular-bow self-guiding bow 444. FIG. 3c shows
square-shaped perpendicular-bow system 445 in which one or more
stacks of mini-bows 434 are oriented to form a rectangular
configuration, and FIG. 3d shows triangle-shaped perpendicular-bow
system 446 in which one or more stacks of mini-bows 434 are
oriented to form a triangular configuration--the combination of
which yields a substantially orthogonal configuration. These are
just a few of the many configurations possible for
perpendicular-bow self-guiding bow 444.
[0059] The advantages of perpendicular-bow self-guiding bow 444
include the following. First and most importantly, a significant
travel, i.e., 2-6 inches, of spring compression can be achieved
with a bow the length of the thigh and/or tibia of the runner--due
to the possibility of using very thin mini-bows 434. Second, it is
easy to manufacture, and the total spring stiffness can easily be
varied to "tune the brace for a particular runner. Third, this ease
in "changing gears" allows one to use a gear-changing mechanism to
engage a variable number of mini-bows to "tune" a running aid for
an individual or to "change gears" while running by utilizing a
mechanism to engage a variable number of min-bows 434.
[0060] FIG. 4 shows a side view of a tibia
perpendicular-spring/brace-foot assembly 25 for use in the first
embodiment of the invention. Tibia perpendicular-spring/brace-foot
assembly 25 can also be used for below-the-knee prostheses, the
only difference being that tipper-tibia pylon 13 connects to the
runner's stump instead of to the upper portion of tibia link 7 of
FIG. 1. The function is the same, namely to absorb and return
impact energy of running. Upper-tibia pylon 13 is rigidly attached
to tipper-tibia end-plate 12, and brace foot 8 is rigidly attached
to brace-foot end-plate 11. Front bows 16 bow to the front, side
bows 15 bow to the outside, and back bows 17 bow to the back--of
the runner, and all are hingeably attached to upper-tibia end plate
12 and brace-foot end plate 12. It is still possible to use the
configuration of FIG. 3c since both stacks of side bows 15, one on
either side of the rectangle, can bow to the outside. This is
necessary so as to not interfere with the runner's other foot.
Tibia perpendicular-spring/brace-foot assembly 25 absorbs and
returns the runner's impact energy without need for a separate,
longitudinal guide system because of the self-guiding capability
described above. Notice that the bottom of brace foot 8 is curved.
The shape of this curve is critical to optimize running
performance, and this point will be explained in the discussion of
the next figure. FIG. 4b shows tapered bow 35 which can be used for
any of the bow springs discussed herein. Its purpose is to make the
rise of the bow force curve to the constant buckling value more
gradual in case this is needed for comfort concerns. The amount of
taper controls the force curve very precisely and easily.
[0061] FIG. 5 shows side views of tibia
perpendicular-spring/hinged-brace-- foot assembly 27. FIG. 5b shows
the landing at heel-down, and FIG. 5a shows the toe-off at
take-off. Tibia perpendicular-spring/hinged-brace-fo- ot assembly
27 is now hingeably connected to brace foot 8 via brace-foot
end-plate 11, rigidly attached to brace-foot end mount 18, and
ankle pivot 23. Brace-foot return spring 22 tilts forward brace
foot 8 against brace-foot rear stop 19 in swing phase. At heel-down
brace heel 24 impacts the ground. During stance, as the runner
continues forward, tibia perpendicular-spring/hinged-brace-foot
assembly 27 rotates forward, like an inverted pendulum, until
brace-foot end mount 18 impinges brace-foot front stop 20--at which
time brace-foot 8 rocks forward over brace forefoot curved bottom
21 until toe-of. Regarding the below-knee prosthesis application,
the advantage of this design is that all of the impact energy is
stored in perpendicular-spring/hinged-brace-foot assembly 27 with
its constant-force curve, and this energy is returned to thrust at
toe-off at the time when it is best utilized. Prior art prostheses
which store energy in heel flat springs and flexing bow shins
either give back the energy too soon, or they give it back with a
linear force curve which does not couple well with the runner's
push-off action. That is, the spring force is too weak at the end
of take-off. Whereas, for a constant-force spring, the spring force
is still optimally high at toe-off. Also, by using hinged, multiple
bows, the spring deflection can easily be as large and optimal as
is needed. Finally, perpendicular-spring/hinged-brace-foot assembly
27 can support sufficient torque for this application without need
for a telescoping-tube guide system.
[0062] FIG. 5c shows a side view of tibia
perpendicular-spring/rigid-brace- -foot assembly 29 which differs
from the design of FIGS. 5a and 5b in that brace-foot end-plate 11
is now rigidly attached to brace foot 8. The intention here is to
reap the benefits of a long brace foot, but this means that the
pitch torque (in the front-back-vertical plane) must be resisted by
the prosthesis. The shape of rigid-foot curved bottom 33 is
designed to minimize this torque. The design benefits then are that
the landing and take-off angles of the runner's leg are optimized,
but these benefits must be traded off with the tolerable pitch
torque. For the running aid application, brace foot 8 is even more
important--to match the length asymmetry of a running brace to the
natural length asymmetry of the runner's leg/foot system which
results from the greater length of the toe-to-hip-joint distance at
toe-off than the length of the heel-to-lip-joint distance at
heel-down. Again, the design goal of length asymmetry for the
running aid and the specific asymmetry achieved depend on the
precise shape of the bottom of brace foot 8. The length of brace
foot 8 controls the amount of length asymmetry and the precise
shape controls the rate (which should be steady) of forward motion
of the effective contact point rate, i.e., the point around which
there is no net torque due to the foot force--between the ground
and the bottom of brace foot 8. That is at toe-off, brace forefoot
curved bottom 21 acts as a rolling pivot to limit the pitch torque
on running aid 2 in FIG. 1. The design of the shape of brace foot 8
to achieve length asymmetry and to optimize performance during the
rollover from heel to toe is referred to herein as the weight
transfer structure.
[0063] FIG. 6 is a side view of running aid 2 from FIG. 1 according
to the second embodiment of the invention; FIG. 7 is a front view
of the same. Here, the bow is decouple from the support. Only one
side of brace leg 9 is shown in each figure, and harness center
line 136 indicates the center of harness 3 in FIG. 7. Running brace
harness 3 shown in FIG. 1 is not shown in FIG. 6, but it is
attached to hip-pivot rim 26 in the actual invention. Runner 1 is
shown in FIG. 6 as a dashed line.
[0064] Hip link 112 is rotatably attached to harness 3 via hip
pivot 28 mounted in hip-pivot block 116. There are three senses of
rotation for pivots, with respect to runner 1. "Pitch" refers to
rotation about the side-to-side axis, "roll"--rotation about the
front-to-back axis, and "yaw"--rotation about the vertical axis.
Hip pivot cannot allow roll because of self-locking knee mechanism
121, to be discussed below. Hip pivot 28 must allow pitch so that
the runner's leg can swing back and forth, and it may optionally
allow roll to allow knee turn-out--for runner 1 to change
direction. Hip link 112 is a support member, and it serves to house
bucky-bow spring mechanism 10 and to slidingly connect with thigh
link 4 which slides along bearings within or beside hip link 112.
Bucky-bow spring mechanism 10 comprises pulley block 104 to which
are mounted inner pulley 106 and outer pulley 108 (rigidly attached
to inner pulley 106). It further comprises bow spring 100 and bow
strings 102 which extend from either end of bow spring 100 around
inner pulley 106. Draw strings 103 then extend around outer 108 to
be caught by spring catch 118 upon impact, as thigh link 4 is
forced upward through hip link 112. Bucky-bow spring mechanism 10
further comprises thigh-link constraint 120 which allows bow spring
100 to bow, but which constrains the center of bow spring 100 to
move straight down hip link 112.
[0065] The function of bucky-bow spring mechanism 10 is to allow
bow spring 100 to absorb the runner's impact energy as thigh link 4
slides up through hip link 112, catching drawstring 103. Drawstring
103 then turns outer pulley 108 which turns inner pulley 106,
pulling tie ends of bow spring 100 together. The mechanical
advantage achieved with this double pulley system allows a greater
travel of draw string 103, and, hence, of bucky-bow spring
mechanism 10, for a given flexing of bow spring 100. This allows a
more lightweight bow for a given strength. For example, a bow
spring 30 inches long and between one and two lbs in weight can
give a constant force of 400 lbs with a draw-string 103 travel of
six inches (same as the human center-of-mass travel). The use of
pulleys also permits the possibility of changing tile stiffness of
spring assembly 5, which is analogous to changing gears on a
bicycle. This change can be done simply with a conventional gear
mechanism--to change the load-carrying pulley strings from one
pulley to another. Finally, bow spring 100 can be inverted and
attached to thigh link 4, so that hip link 112 pulls down on draw
string 103, but it is preferable to have the weight of the lower
brace support on hip link 112.
[0066] In order for spring assembly 5 to carry out this function of
bow-loading, self-locking knee mechanism 121 must be locked. That
is, tibia link 7 must be loaded so that it exerts clockwise torque
about knee pivot 6, causing thigh-link constraint 120 to impinge
against tibia-link constraint 122--in which case self-locking knee
mechanism 121 is self-locked. Looking now at brace foot 8, tibia
link 7 transmits the impact load to the ground via its rotatable
(pitch) connection with knee pivot 6 on the top and its rigid
attachment to brace foot 8. Heel pivot 130 connects brace foot 8 to
the runner's foot behind her heel guaranteeing the release of
self-locking knee mechanism 121, to be discussed with FIG. 9.
[0067] FIG. 8a is a side view of gas spring 30 with gas reservoir
34 which is the third embodiment of the invention. This combination
can be used to achieve a substantially constant spring force curve.
This substantially constant force curve is achieved by
pre-pressurizing the gas to get a high initial pressure or spring
force and a low force-curve slope as gas spring 46 deflects. A
working definition of a constant force curve is that the average
force over the range of deflection is greater than 70% of the
maximum value during that deflection. For example, if a force curve
is linear, the average force is 50% of the maximum. Increasing the
pre-pressure (unloaded) value and the reservoir volume results in
an increase of this average force value with respect to the maximum
force value, but there must be a trade-off with weight. Tile
running impact force compresses gas spring 30 as chamber cylinder
40 slides down around piston 38. Gas line 32 transmits the pressure
to gas reservoir 34 located above lip pivot rim 26. A single gas
reservoir 34 can be used for both gas springs on both legs. The
preferred gas in gas springs 30 is air, but it may be another
gas.
[0068] FIG. 8b is a schematic side view of gas pump 36 for
replenishing lost gas in pressurized gas spring 30. Gas pump 36 is
mounted next to gas spring 30 so that, when gas spring 30 is
compressed, the gas pressure in pressure chamber 56 increases as
pump piston 46 and gas seal 48 are pushed down by piston shaft 50.
When the pressure in pressure chamber 56 exceeds the pressure in
gas spring 30 to which it is connected via feeder tube 60, gas
leaks through check valve 52 into gas spring 30. If the pressure
there gets too high, pressure release valve 54 releases the
pressure. On the return stroke, inlet hole 58 allows gas into
pressure chamber 56 for the next pressure stroke.
[0069] FIG. 9 is a side view of the support part of self-locking
knee mechanism 121 of the running aid according to the fourth
embodiment of the invention. It simplifies the picture of how this
self-locking is achieved by showing only the components needed for
this demonstration. The purpose of self-locking knee mechanism 121
is to ensure that the support elements, thigh-link assembly 4 and
tibia link 7 are locked straight during stance phase and free to
bend about knee pivot 6 during swing phase. As the runner's leg
extends before foot strike, these support elements approach the
straight orientation shown FIG. 9a, from the folded orientation
shown in FIG. 9b.
[0070] Self-locking knee mechanism 121 is shown in FIG. 9c, and its
purpose is to ensure that thigh-link constraint 120 and tibia-link
constraint 122 close completely before foot strike for the
self-locking to occur. This closing can also be referred to as the
hyper-extension force. Posts 146 are rigidly attached to tibia link
7 and thigh link 4; center post 150 is rigidly attached to
knee-pivot block 152. Knee spring 148 is attached to posts 146 and
passes over center post 150, it acts to close thigh-link constraint
120 and tibia-link constraint 122 completely, and it is strong
enough to ensure this closing, but weak enough to allow the
runner's lifting leg to fold knee pivot 6 at toe-off. Note that by
shortening posts 146 and/or center post 150 it is possible to
reduce the hyper-extension force to any desired value after the
knee pivot has folded beyond a particular angle, thereby reducing
the force that the runner must exert in high kick.
[0071] At heel-down, the heel portion of aid foot 8 strikes the
ground at the location of heel arrow 143, and heel centerline 142
indicates the line of force between hip pivot 28 and the ground.
Since heel centerline 142 passes to the left of knee pivot 6, this
impact force pushes thigh-link constraint 120 and tibia-link
constraint 122 together, and self-locking knee mechanism 121
remains locked. As aid foot 8 rolls over forward until toe-off from
the location of toe arrow 145, the force curve indicated by toe
centerline 144 still passes to the left of knee pivot 6, and knee
pivot 6 remains locked. immediately at toe-off, the runner lifts
her foot which is rotatably connected to heel pivot 130, at which
time the force curve passes to the right of knee pivot 6, as
indicated by foot-coupling pivot center line 140--between
foot-coupling pivot arrow 141 and hip pivot 28--causing tibia link
7 to fold about knee pivot 6 as seen FIG. 9b. The advantage of
self-locking knee mechanism 121 is that it circumvents the problem
of a knee-pivot lock, which is a very difficult problem because of
the weight and strength constraints in view of the large torques
involved. This self-locking can also be achieved with a foot-aid
coupling in front of the runner's foot, but this approach is not as
convenient. Also, the device can be prevented from locking at all
by walking on very bent knees, e.g., up a steep hill or up stairs,
or a mechanical switch can be incorporated into self-locking knee
mechanism 121 to prevent thigh-link constraint 120 from approaching
close enough to tibia-link constraint 122 for the self-locking to
take effect, thereby allowing the runner to walk or climb a steep
hill.
[0072] FIG. 10 is a side view of 4-bar foot-lift assembly 85 for
maintaining clearance of aid foot 4 above the ground during swing
phase. Foot-lift link 86 hingeably connects the front of aid foot 8
via toe pivot 88 to thigh-link extension 87 via foot-lift pivot 89.
Thigh-link extension 87 extends rigidly from thigh link 4. When
knee pivot 6 folds, thigh-link extension 87 lifts aid foot 8 via
foot-lift link 86, thereby preventing aid foot 8 from dropping
below the runner's foot and tripping him. FIGS. 10a, 10b and 10c
display 4-bar foot-lift assembly 85 at various degrees of folding
and straightening. FIG. 10a shows that both foot-lift pivot 89 and
knee pivot 6 have straightened to hyper-extend and lock against
foot-pivot constraints 91 and tibia-link constraint 122 and
thigh-link constraint 120, thereby ensuring that both foot-lift
link 86 and tibia link 7 transmit the running impact load to aid
foot 8. And, when heel pivot 130 lifts aid foot 8 and releases the
locking of both foot-lift pivot 89 and knee pivot 6, the runner can
high kick his foot behind him. FIG. 10d shows thigh link 4 and
thigh-link extension 87 as a single rigid element. Both foot-lift
pivot 89 and knee pivot 6 require closing mechanisms ( not shown
here for clarity) to ensure that they close at heel down, such as
the spring system shown with self-locking knee mechanism 121 in
FIG. 9c.
[0073] FIG. 11 is a front cross-sectional view of variable-angle
knee lock 61 which is a more versatile and sophisticated
alternative to self-locking knee mechanism 121 of FIG. 9 and which
is the fifth embodiment of the invention. The idea behind this
device is to make a shaft/collar system which turns freely when
loaded on one side and which locks very strongly when loaded on the
other side. By interleaving a number of strips, alternating between
strips attached to the shaft and strips attached to the collar, it
is possible to magnify the friction force by the number of
interfaces between alternating strips. This means that a very large
lock force can easily be achieved with a number, perhaps five or
ten, of very thin, light, cheap metal circumferential strips 78.
Also, the goal of this design is to load the lock radially rather
than axially--as is done with conventional car disk brakes. This
radial loading eliminates the need for a force re-direction
mechanism.
[0074] FIG. 11a shows hollow shaft 62 (optionally hollow) and split
collar 69 assembled together. The top portion of hollow shaft 62
and upper collar 70 form a cylindrical bearing surface so that when
hollow shaft 62 pushes up against upper collar 70, they rotate
freely. FIG. 11c shows shaft boss 64 which is attached to the lower
portion of hollow shaft 62 by boss screws 67. Boss spacers 68
interleaf with circumferential strips 78--all of which extend
circumferentially around the bottom portion of hollow shaft 62.
This circumferential extension can been seen in FIG. 12 which is a
side view of variable-angle knee lock 61. Boss screws 67 tighten
boss stack plate 77 against boss spacers 68 interleaved with
circumferential strips 78 and against shaft boss 64. Thus,
circumferential strips 78 are fixedly attached to hollow shaft
62.
[0075] FIG. 11b shows lower collar 71 with circumferential strips
78--both of which are attached to shaft boss 64 by boss screw 67.
The attachment of circumferential strips 78 to lower collar 71 is
accomplished in a similar manner to their attachment to hollow
shaft 62. Collar screws 73 tighten collar stack plate 66 against
collar spacers 79 interleaved with circumferential strips 78 and
against lower collar 71.
[0076] FIG. 11a shows in assembly that alternating circumferential
strips 78 attached to shaft boss 64 and lower collar 71 interleaf
between each other. Thus, when lower collar pushes up against
hollow shaft 62, a friction force is exerted between these
alternating circumferential strips 78 attached to shaft boss 64 and
lower collar 71. Specifically, this upward pushing causes the
portion of lower collar 71 radially external to the interleaf
region to compress the stack of interleaved circumferential strips
78 against shaft boss 64, thereby locking hollow shaft 62 from
rotating in lower collar 71. The radial dimensions of collar recess
74 and shaft boss 64 are chosen to ensure that this compression and
locking is unimpeded. Again, the frictional force of this device is
proportional to the number of circumferential strips 78 and can
easily be magnified to a very large value.
[0077] The circumferential ranges of extension of lower collar 71
and shaft boss 64 can been seen in FIG. 12 which is an assembly
side view of variable-angle knee lock 61 and in FIG. 13 which shows
the shaft and collar components separately. This particular choice
of angular ranges gives a locking range of over 70 degrees which is
more than adequate for the range of bent-knee angles needed for
natural running, as can be seen in FIGS. 14a and 14b which show the
rotation of lower collar 71 around shaft 62. Lower collar 71 is
fixedly attached to tibia shaft 7, and shaft 62 is fixedly attached
to thigh link 4, Again, the upward force of lower collar 71 on
shaft 62 will cause locking over the range of tibia 7 rotation
shown in FIG. 14. Since thigh link 4 and tibia link 7 are
approaching being aligned whenever foot impact occurs, it is likely
that the jarring force transmitted up tibia link 7 to lower collar
71 will be sufficient to lock variable-angle knee lock 61, as is
the case with prior-art, above-the-knee prostheses. If more force
is needed, a foot-contact trigger can be used to initiate the
locking of variable-angle knee lock 61. For example, a "brake
cable" could transmit foot-impact force to close split-collar 69 by
having collar attachments 75 provide a sliding connection between
lower collar 71 and upper collar 70 rather than a fixed attachment
provided by collar attachment 75. It should be understood that if
the bearing surfaces are located on the bottom side rather than the
top side, thigh link 4 can be attached to split collar 69 and tibia
link 7 to hollow shaft 62. Finally, variable-angle knee lock 61
allows uphill running, and it results in an effective gear changing
because the spring action is not as aligned with the thrust action
when variable-angle knee lock 61 locks at a more bent position.
[0078] FIG. 15 is a side view of variable-angle knee lock 61
showing damper 82 for use with variable-angle knee lock 61. When
tibia link 7 swings forward just before heel strike, it is
important to prevent it from over-hyper-extending and from bouncing
back off a stop. This is accomplished with damper 82 fixedly
attached to damper arm 80 fixedly attached to thigh link 4. FIG.
15b shows tibia link 7 swinging forward in the direction indicated
by arrow 84 and approaching the straight-leg position. FIG. 15 a
shows that damper 82 absorbs the momentum of tibia 7 and stops it
near the straight position. It should be understood that
variable-angle knee lock 61 can optionally utilize a device to
ensure that it opens to a straight orientation at heel-strike such
as that shown in FIG. 9c. Also, since variable-angle knee lock 61
locks over a range of angles, a simple damper such as a foam, gel
or bladder can be used. This is an advantage over conventional knee
locks used ill above-the-knee prostheses which use expensive and
sophisticated hydraulic mechanisms to prevent bounce back over a
range of gaits. And, it should be understood that variable-angle
knee lock 61 has applications in robots and above-the-knee
prostheses. Also, there are other ways obvious to one of ordinary
skill in the machining and fabrication arts to construct
variable-angle knee lock 61--that do not depart from the device
intent to radially load interleaving strips so as to magnify
considerably the pivot lock force.
[0079] FIG. 16 is a side view of 4-bar foot-lift assembly 85
showing tibia lock-release 93 for use with variable-angle knee lock
61. The purpose is to ensure knee-lock release at toe-off as was
done in the example of self-locking knee mechanism 121 shown in
FIG. 9. In this case the hyper-extended, constrained pivot lock is
located near the middle of what was tibia link 7 in earlier
figures. The 4-bar foot-lift assembly 85 is the same as that shown
in FIG. 10, but now tibia-link 7 comprises lower tibia-link 96,
tibia pivot 92 and upper tibia-link 94. The ends of upper
tibia-link 94 and lower tibia-link 96 connected to tibia pivot 92
have double constraints 90 which serve to lock tibia pivot 92 on
the hyper-extending side and to limit the folding of tibia pivot 92
on the other side. The lifting of aid foot 8 by the runner's foot
via heel-pivot 130 breaks the hyper-extended locking action of both
tibia pivot 92 and foot-lift pivot 89 as shown in FIG. 16b. FIG.
16c shows a blow-up of the components of tibia lock release 93.
[0080] FIG. 17 is a back view of cable system 200 which allows the
use of single bow spring 202 in the sixth embodiment of the running
aid invention. That is, one bow, located behind the runner's back,
is used for either leg instead of two (one on each leg) as shown in
FIG. 6. This embodiment requires a system of pulleys to direct the
force of single bow spring 202 to the runner's sides. For clarity,
only the pulleys are shown, and the support attachments of the
various pulleys are mentioned in this specification. Thigh link 4
transmits the impact force by pulling upward with pulley catch 118
on pulley cable 210 which passes around side pulley 205 (rotatably
mounted to thigh link 4; mounting not shown). Pulley cable 210 next
transmits the force back to back-pulley 206, mounted on back
support 208, and then up to up-pulley 204, also mounted to back
support 208. Actually, side pulley 205 will be directly in front of
back pulley 206, but they are shown slightly offset here for
clarity. Next, the force is transmitted to outer pulley 108 and to
inner pulley 106, which are mounted behind the runner to back
support 208, which is rigidly attached to hip pivot rim 26. Single
bow spring 202 is connected to and interacts with outer pulley 108
in a manner similar to that shown with bow spring 100 in FIG. 6,
the difference being that single bow spring 202 can absorb impact
force from the brace elements on either or both sides.
[0081] FIG. 18 shows full harness 300 for the running aid with the
front view on the left and the side view on the right. In the front
view, runner 1 is shown in dashed lines, and the coupling between
runner 1 and full harness 300 is made via pelvic rim 26 from FIG.
6. Full harness 300 can be subdivided into thigh harness 302,
pelvic harness 304, waist harness 306, and chest harness 308, and
each of these can be further subdivided into multiple cuffs 310.
Later, a figure will show a means to take some of the brace load on
the arms of runner 1, as well. Stays 312 are rigidly attached to
pelvic rim 26 and extend upward and downward from it to support the
elements of full harness 300 via cords 314. Only the portion of
pelvic rim 26 at either side is shown for clarity, but it encircles
runner 1. Only those stays 312 on either side are shown for
clarity, but there may be multiple stays around pelvic rim 26.
Cords 314 can independently support each cuff to better distribute
the brace load along the length of full harness 300, and there may
be one or more cuffs 310 in each harness subdivision. Finally, only
a portion of the full harness 300 shown may be needed and used in
this invention.
[0082] One very important feature of this extensive harness is that
the harness portions which support and upward pull can be tightened
down against the harness portions which support a downward pull.
For example in FIG. 18, waist harness 306 can be cinched down to
thigh harness 302 with straps, and vice versa. This allows the
compliance of the underlying runner's flesh to shear to be reduced
substantially.
[0083] It may be possible to comfortably support a runner with
harnesses that are simply tight and extensive, but the following
discussion gives designs for harness in which the load of the
runner on the running brace tightens the harness. This
load-tightening feature may be used with a portion or all of full
harness 300. The advantages are (1) that the harness tightens as
the load increases, thereby increasing its load capability and (2)
the harness loosens when not loaded, thereby improving blood
circulation and comfort for the runner.
[0084] FIG. 19 is a side schematic view of a generic mechanical
design for . mechanical load-tightener cuff 322 used in full
harness 300 for the running aid. In the bottom section of FIG. 19,
load-tightening cuffs 320 overlap and in the top section they do
not. Looking at the top section, the two ends of load-tightening
cuffs 320, which encircle a portion of the runner's body part, are
attached to adjacent cuff buckles 328, which, in turn, are attached
to mechanical load tightener 322 via tightening cords 324. When the
brace load pulls up on mechanical load tightener 322 as indicated
by load arrow 330, mechanical load tightener 322 causes tightening
cords 324 to pull inward as indicated by tightening arrows 330,
thereby tightening load-tightening cuffs 320. Referring to the
bottom section of FIG. 19, the same tightening occurs. The
difference is that mechanical load tightener 322 must be wide
enough to pull together either side of load-tightening cuffs 320
which now overlap by virtue of ending with cuff fingers 334. The
advantage of this overlapping is that the surface of
load-tightening cuffs 320 is smooth in the vicinity of mechanical
load tightener 322, thereby providing greater comfort to the
runner. In the following examples of load-tightening designs, only
one will show this overlapping, but it should be understood that
any of them can be adapted for overlapping.
[0085] Regarding the use of load-tightening cuffs 320 in general,
these may comprise means for lacing or cinching to achieve a snug
yet comfortable degree of pre-tightening. Further pre-tightening
may be achieved by tightening different levels of the harness, one
against the other. For example, waist harness 306 may be cinched
down against pelvic harness 304 to reduce the compliance between
the runner's flesh and the harness. Depending on how much soft
tissue there is below the runner's skin, the skin may move a
half-inch to an inch or more under shear. Pre-tightening can
eliminate most of this compliance.
[0086] FIG. 20 shows examples of compressible woven harness 340 for
load-tightening sleeves of the harness for the running aid. On the
left side thigh harness 302 and torso harness 344 are held at
either end by hoops 342. Braids 346 are interwoven about the shape
of a pelvis and thigh. Provided their lower sections are
sufficiently anchored, when the upper hoop 342 pulls upward,
compressible woven harness 340 must shrink or compress, and this
results in gripping of the underlying object, in this case the
runner's body pails. In order for this gripping to occur, the
individual braid material which composes compressible woven harness
340 must be inelastic to stretching, but flexible to bending over
the shape of the underlying object. This idea is similar to that
used for the finger traps known as Chinese hand cuffs, in which a
number of bands (tapes, ribbons, strips) are inter-woven into a
tube which traps the fingers of unwary children. On the right side
of FIG. 20 compressible woven harness 340 is composed of braids 346
in such a manner that there is substantial void space between
braids 346. This has several advantages: ventilation for the
runner, a greater compression range, and improved traction of
braids on the compressible human flesh underneath. The relative
amount of contraction for a given extension between hoops 342
depends on the number, width, thickness and pitch angle of braids
346, as well as on their friction coefficient with the underlying
surface. If the underlying surface is irregular, it can also be
seen that judicious locations of stays 312 and cords 314 in FIG. 8
can improve the even distribution of load along the length of a
harness.
[0087] An important feature of the woven mesh design is that the
bottom portion of the sleeve must be sufficiently well anchored as
to cause the higher regions to contract and thereby distribute the
(upward) load up the entire sleeve length. This may be accomplished
for thigh sleeve 20 with straps extending down and around the foot
or with straps extending to a stuff around the runner's tibia below
the knee. Or, since the runner's thigh has a natural taper, keeping
the lower portion of thigh sleeve 20 fairly tight may be sufficient
in some cases to achieve this anchoring. Once sufficient bottom
anchoring is achieved, the load is distributed up the length of
compressible woven harness 340, which is the overall goal.
[0088] FIG. 21 is a side view of overlap double-pulley load
tightener 318 which is an example of a mechanical load-tightener
322 used in the harness for the running aid. Tile discussion here
is similar to the discussion of mechanical load-tightener 322 for
FIG. 9 except that mechanical load tightener 322 is shown in detail
rather than schematically. Mechanical load-tightener 322 comprises
load-tightening cuff 320 attached on either end to cuff buckles 328
and overlapping each other via cuff fingers 334. It further
comprises spreader bar 323 which is mounted to load-tightening cuff
320 at spreader bar tab 325 and which has rotatably mounted on
either end tightening pulleys 336. When the brace load pulls up on
stay cords 326 at indicated by load arrows 332, stay cords 326 pass
around tightening pulleys 336 to pull tightening cords 324 as
indicated by tightening arrows 330, via cuff buckles 328, thereby
tightening load-tightening cuffs 320. Spreader bar 323 is anchored
below via anchor cords 327 as indicated by anchor arrows 329. At
first, it may seem self-defeating to require additional anchor
cords for spreader bar 323 because the goal is to be able to pull
up on load-tightening cuffs 320 with the brace load via stay cords
326 and the attachment to spreader bar 323 at spreader bar tab 325.
If load-tightening cuffs 320 are already tight enough, anchor cords
327 are not needed, but they provide back-up as the tightening
begins. The top section of FIG. 21 shows a blow-up of tightening
pulley 336 which optionally may comprise inner tightening pulley
338 and outer tightening pulley 339. In this case, there is a
mechanical advantage whereby the travel of stay cord 326 is
augmented by a factor equal to the mechanical advantage between
these pulleys to create a greater travel of tightening cord 324.
This is an important feature because it reduces the slack or
compliance needed to tighten mechanical load-tightener 322. This
means that the running aid can give substantial support to the
runner quicker, and this is key to natural running.
[0089] FIG. 22 is a side view of bent-lever load tightener 350,
jamming load tightener 352, and inward-force load tightener 375 of
the harness for the running aid. These are examples of the
mechanical load tighteners 322 shown in FIG. 9 and FIG. 21, and the
first two function in a similar manner. Bent-lever load tightener
350 is shown in the bottom left of FIG. 22. Bent levers 356 are
rotatably attached to spreader bar 323 which is attached to
load-tightening cuff 320 via cuff hoop 354. Cuff hoop 354 is
slidingly attached to load-tightening cuff 320 so as to not impede
its tightening. Provided load-tightening cuff 320 is well
pre-tightened or provided spreader bar 323 is well anchored below,
when stay cord 326 pulls up (see load arrow 332) the top arms of
bent levers 356, then the bottom arms of bent levers 356 pull the
ends of load-tightening cuff 320 inward via cuff buckles 328 ( see
tightening arrows 330). A similar function occurs for jamming load
tightener 352 in the top left of FIG. 22 Here, as spreader bar 323
is pulled up, jamming links 358 tighten load-tightening cuff 320.
It should be understood that cuff hoop 354 can be used with any of
the cuffs discussed herein, and it may be segmented or telescoping
to allow cuff 20 tighten. Inward-force load tightener 375 is shown
on the right of FIG. 22, and it functions slightly differently.
Frame hoop 379 is rigidly attached to harness 3 of FIG. 1 and
encircles body part 378, and it is strong enough to be rigid when
the jamming links 358 on either side jam against pressure pads 376
on either side to grip body part 378 as a brace load force pushes
up on frame hoop 379--to clamp or grip body part 378 as it is
supported. It should be understood that there may be a number of
these elements distributed about the body harness, and there are a
number of mechanisms known to one of ordinary skill in the art for
accomplishing this gripping. Again, this last load-tightening
mechanism is distinguished from the earlier ones by virtue of the
fact that the clamping force is directed inward toward the body
part instead of circumferentially around the part body tightening a
cuff.
[0090] FIG. 23 is a side view of combination mechanical/weave
load-tightener 360 of the harness for the running aid. Its purpose
is to lift and simultaneously apart spread compressible woven
harness 340. Vertical spreader bar 364, attached to top hoop 370,
pulls upward on compressible woven harness 340--attached at its top
to top hoop 370 and its bottom to bottom hoop 372. This upward pull
is exerted by cables 366 which pass firm vertical spreader bar 364
around block pulleys 362, and then all the way down to pass around
spreader pulleys 363--attached to the bottom of vertical spreader
bar 364--to finally pull down on bottom hoop 372, thereby spreading
compressible woven harness 340 and causing it to contract and grip
the underlying body part. Block pulleys 362 serve to equalize the
upward force on top hoop 370 with the downward force on bottom hoop
372. Cable arrows 374 indicate the pull directions that achieve the
spreading apart of compressible woven harness 340. Tills spreading
causes a quicker gripping of the body part, which eventually is
lifted when the gripping force becomes sufficiently large.
[0091] FIG. 24 is a side view of arm load-bearing harness 380 for
the running aid. Runner 1 and runner's arm 390 are shown as a
dashed line. Tile lower running aid is not shown bit is attached to
pelvic rim 26 as is shown in earlier figures. Arms beam 392 is
rigidly attached to pelvic rim 26, and swing links 384 are
rotatably attached to arm beam 392 to support arm rest 388 which
supports runner's arm 390 via arm pad 386. Accordingly, runner 1
can support a substantial portion of her weight on arm load-bearing
harness 380 and still swing her arms.
[0092] FIG. 25 shows a schematic front view of load-equalizer stay
tree 400 which distributes the brace load over various parts of the
harness for the running aid. On the left side of the figure stays
312 support cords 314 which attach to cuffs 310, which make Up a
body harness. In this case, the load will be distributed
approximately evenly over each cord 314 and cuff 310. If one wishes
to vary the load on a particular cuff 310, the elasticity of the
attached cord 314 can be varied. In the event that one wishes to
ascertain that there is an even load distribution without have to
make all the cords 314 just the right length, load-equalizer stay
tree 400 may be used. Here, cords 314 are attached at one end to
the bottom of load-equalizer stay tree 400 and at the other end to
the top cuff 310. In between, cord 314 passes over stay pulleys
alternately attached to cuffs 314 and load-equalizer stay tree 400.
The result is that load-equalizer stay tree 400 pulls up evenly on
cuffs 310 via the attached pulleys. The detailed and workable
design is more involved, but this figure demonstrates the
principle.
[0093] FIG. 26 shows adjustable harness 403 for the running aid.
Adjustable bands 404 pass around a body part and through fitting
clamps 406. When adjustable bands 404 are pulled to fit tight about
the underlying body part, a portion--namely leftover bands 408--of
their lengths stick out the other side of fitting clamps 406. In
this way a range of sizes and shapes can be snugly fit with
adjustable harness 403. The same device can be use to adjust braids
346 which make up compressible woven harness 340 in FIG. 20. This
adjustability is important because a self-tightening harness
material should have minimal elasticity.
[0094] FIG. 27 shows a side view of a generic brace leg with a
circular brace foot 8, demonstrating graphically how well the brace
foot prevents vertical travel of the runner's center of mass
throughout stance. The figure depicts a stick leg, brace leg 9,
running from left to right. The stick figure on the left shows
heel-strike and on the right shows toe-off. Tile center sequence
shows the trajectory of the top of brace leg 9 throughout stance,
at 10 degree intervals of rotation--with alternating positions
being either solid or dashed. In the first 10 degrees, the brace
top rises 0.5" (for a 30" leg); for the next 30 degrees, the brace
top stays level because the radius of brace foot 8 is also 30", and
for the last 10 degrees the brace top falls 0.5". The curved brace
foot can be used with any of the embodiments for the running aid
herein, or it can be used in the tenth embodiment with a straight
rigid leg as shown in FIG. 27. In this case the "running aid" is
actually a walking brace used for support.
[0095] FIG. 28 shows hyperlocker 500, a mechanism to guarantee
hyper-extension of the self-locking knee mechanism of the fourth
embodiment of the invention of FIG. 9. Thigh link 4 rotates about
lip pivot 28. Since the direction of running is from right to left
on the page, the right side depicts the early stage of swing phase
after toe-off The left side depicts the instant just before
heel-strike when knee pivot 6 is hyper extended. The purpose of
hyperlocker 500 is to force hyper-extension before heel-strike,
while still being able to freely fold knee pivot 6 at toe-off. This
is done by keying hyperlocker 500 to the position of thigh link
4--either swung forward or backward. When thigh link 4 swings
forward (leftward), slide-pulley cord 526 pulls slidable thigh
pulley 524 up, via top thigh pulley 520 against rim beam 518.
Closer cord 514 runs from closer-link attachment 510 around
thigh-link pulley 512, up to slidable thigh pulley 524, back down
to and through beam pulley 506 (on the end of upper closer beam
502, to end at cord ball 522. When thigh link 4 is swung back,
slidable thigh pulley 524 slides down thigh link 4, and closer cord
514 has enough slack so as to allow closer links 508 to bend and
knee pivot 6 to fold with no resistance from closer cord 514.
[0096] However, when thigh link 4 swings forward (leftward, in
swing phase), slide-pulley cord 526 pulls slidable thigh pulley 524
up thereby pulling closer cord 514 taut. Now, when tibia link 7
starts to move down to prepare for heel-strike, closer-cord catch
516 on the end of lower closer beam 504 catches cord ball 522,
causing closer-link attachment 510 to be pulled toward thigh-link
pulley 512, causing the hyper-extension of tibia link 7 about knee
pivot 6. By adjusting the various parameters, it is possible to
choose the fold angle at which the hyper-extension action begins.
Also, a spring can be incorporated in closer cord 514.
[0097] FIG. 29 shows slider 530 for changing the length of a
running aid according to the seventh embodiment of the invention.
Slider 530 comprises middle guide 564 and inner guide 566 (which
may be telescoping tubes) as well as slider ratchet 532. The
purpose of slider 530 is to change the length of the running aid
even when knee pivot 6 is hyper-extended, to allow uphill running.
Slider 530 changes length freely during swing phase; at
heel-strike, a foot-contact trigger, such as the one shown in FIG.
30, engages slider ratchet 532 to lock slider 530 throughout
stance. When the total brace length can be changed in two ways,
with a slider and a knee pivot, it is important to ensure that the
hyper-extension of the knee-lock occurs. Hyperlocker 500 of FIG. 28
ensures this. Note that bow guide 110, comprising outer guide 562
and middle guide 564, significantly overlaps slider 530--allowing
greater length for both elements.
[0098] FIG. 30 shows full-stance brace-foot trigger 540 for locking
slider 530 throughout stance. An array of ground levers 542 are
rotatably attached to curved brace foot 8 along its length. The
tops of these are fixably interconnected by ground trigger cord
546, each of which pulls ground trigger cord 546 around ground
pulley 544 and down the length of tibia length 7, when that ground
lever 542 is caused to rotate by contact with running surface 37.
This is true at heel-strike, shown on the right side of the figure,
until toe-off, on the left side of the figure. That is, even though
each particular ground lever is not always in contact with running
surface 37, there is always at least one ground lever 542 in ground
contact. Since all ground levers 542 are interconnected at their
tops, it only takes one ground lever 542 to pull on ground trigger
cord 546, ensuring that the force engaging slider ratchet 532 of
FIG. 29 is exerted throughout stance.
[0099] FIG. 31 shows foot-coupling guaranteed release mechanism 548
for release of slider ratchet 532 of FIG. 29 at toe-off. This can
be used in place of the hyper-extended knee locks of FIGS. 9, 10,
and 29 to prevent a knee lock or a slider lock from sticking due to
premature lifting of his foot by a runner. Foot pivot square
extension 552 extends from the shaft used for pivotable coupling
between a runner's foot and brace foot 8. The idea is for foot
pivot square extension 552 to freely move up within down-spring
slot 549 just at toe-off, thereby reducing any upward force exerted
by the runner's foot on the brace foot for an instant, allowing any
slider lock to release. During swing phase, foot pivot square
extension 552 must be returned to the bottom of down-spring slot
552 to prevent brace foot 8 from hanging below the runner's foot
and tripping him. This return to the bottom is accomplished with a
spring cocked by the force of heel-strike and then released by the
upward motion of foot pivot square extension 548.
[0100] In detail, FIG. 31a depicts the mechanism during stance.
Ground lever 542 is rotated by ground contact to hold down foot
pivot square extension 552. Down spring 554 is cocked and held in
place by down-spring pawl 556. Down spring 554 was cocked by the
rotation of grounded lever 542 at heel-strike, via the downward
pull on cocking cord 560 which rums over cocking pulley 558 to pull
up on down spring 554. FIG. 31b depicts the instant just after
toe-off. Ground lever 542 is pulled upward by ground-lever return
spring 550 releasing foot pivot square extension 552 to be lifted
by the runner's foot, (This is when foot pivot square extension 552
freely moves up within down-spring slot 549; this free motion
allows slider ratchet 532 of FIG. 29 to release.) pushing
down-spring pawl 556 to the side until it releases down spring 544
which pushes foot pivot square extension 552 back to the bottom of
down-spring slot 549 (as shown in FIG. 31c) where it stays until
heel-strike. FIG. 31d shows the beginning of heel-strike. Ground
lever 542 is being rotated to pull down cocking cord 560 to pull Up
and cock down spring 554 as it is pulled high enough for
spring-loaded down-spring pawl 556 to rotate and catch it--at which
time FIG. 31a applies again.
[0101] FIG. 32 shows simple-slider running aid 561 according to the
eighth embodiment of the invention, wherein a knee pivot is no
longer used. The elements of slider 530 and bow guide 100 have been
explained in the discussion of FIG. 29. Instead of having a knee
pivot connect to a tibia link below bow guide 100, inner guide 566
extends straight down, all the way to brace foot 8. This embodiment
is simple in that it eliminates the knee pivot and all the related
mechanisms, but its drawback is that it is not possible to
high-kick as high. Full-stance ground trigger 540 of FIG. 30 and
foot-coupling guaranteed release mechanism 548 of FIG. 31 can be
incorporated in this embodiment. It is possible that the spring
which causes slider ratchet to pull away from and disengage from
inner guide 566 can be strong enough to guarantee slider lock
release in which case foot-coupling guaranteed release mechanism
548 would not be needed. The top of outer guide 562 would be
attached to hip pivot 28 in a manner similar to that shown in FIG.
6.
[0102] On the right side of FIG. 32 there is shown retractable
brace foot 545 with lockable hinged extensions 547 which can be
locked for running or walking on relatively flat or shallow sloping
terrain and which can be retracted for running or walking on steps
or steep terrain.
[0103] FIG. 33 shows a means to combine an active power source with
a passive spring according to the ninth embodiment of the
invention. In this case actuator piston 44 is propelled downward
within actuator housing 43 during the active power stroke. This
results in an upward force on actuator housing 43 and on bow guide
110 which compresses bow spring 100. Even if the power stroke is of
very short duration, the timing of the expansion of bow spring will
be slow enough to appropriately couple with the runner's weight at
the top of bow guide 10. In effect, the active component extends
the power stroke delivered by the bow spring, and the timing
problem is solved by putting the active component in series with
the passive component.
[0104] FIG. 34a shows booted lockable hydraulic slider 571 and FIG.
34b shows nested lockable hydraulic slider 594 both of which can be
used for the various lockable sliders. The idea is to utilize the
resistance of flow of fluid through a valve to lock, unlock, or
control the length change of the two brace length-change means
discussed herein: namely, knee pivot 6 of FIG. 1 and slider 530 of
FIG. 32. Referring to FIG. 32a, booted lockable hydraulic slider
570 comprises hydraulic piston 576 which slides within hydraulic
cylinder 575. Fluid flows between hydraulic chamber 578 and bladder
boot 581 through top orifice 579, through fluid lines 586, and
through the following valve system. Fluid line 586 branches to go
through return check valve 580 (allowing fluid to return to
hydraulic chamber 578) on one side and through exit valve 582 and
exit check valve (allowing fluid to exit hydraulic chamber 578) on
the other side.
[0105] Exit valve 582 is triggered (by release of toe contact using
the full-stance ground trigger 540 of FIG. 30) to open at
toe-off--thereby allowing fluid 572 to move into reservoir 574 as
hydraulic piston 576 moves tip during the runner's high kick after
toe-off. Since there is no resistance to this opening of exit valve
582, even if the runner's foot is prematurely lifting the brace
foot, the release of lockable hydraulic slider 570 is
guaranteed.
[0106] In swing phase, hydraulic piston 576 is now free to move
both up and down as one check valve allows fluid to flow in and the
other allows fluid to flow out. Just before heel-strike, exit valve
582 is triggered ( by pre-strike heel contact) to close. At
heel-strike, hydraulic piston 576 cannot move up because exit valve
582 is closed. Thus, lockable hydraulic slider 570 is locked. In
view of the fact that some running brace designs require hydraulic
sliders to resist considerable non-axial loads, piston sliding
friction is reduced by not using o-rings. This is possible since
bladder boot 581 receives any fluid that leaks through the small
area between hydraulic piston 576 and hydraulic cylinder 575;
bladder boot 581 is sealed by ring seals 583.
[0107] Cylinder rollers 585 resist any non-axial load in any design
application where hydraulic piston 576 slides under load. For
example, in order to walk down steps or to run downhill, exit valve
582 can be controlled to be partially open, allowing 576 hydraulic
piston to move slowly upward and lockable hydraulic slider 570 to
slowly compress. The size of the opening of exit valve 582
determines how fast the runner or walker can walk down steps, and
the valve can be controlled manually by the runner.
[0108] FIG. 34b shows that one telescoping element can be nested
within another to achieve a higher "high-kick" by the runner just
after toe-off. Also, conventional 0-rings are used to prevent fluid
leakage for this case where the bladder reservoir is not booted.
Nested lockable hydraulic slider 594 further comprises inner piston
588 which telescopes within hydraulic piston 576, which now has a
hole, fluid opening 590, to allow fluid to flow from inner
hydraulic chamber 592 through hydraulic chamber 578 to reservoir
574. The timing of the triggering is the same as that just
discussed.
[0109] Again, nested lockable hydraulic slider 594 and booted
lockable hydraulic slider 571 can be simply substituted for the
sliders discussed elsewhere herein, or it can be used to lock a
knee pivot. FIG. 35 shows knee pivot 6 locked by lockable hydraulic
slider 570 according to the eleventh embodiment of the invention.
The triggering is the same as that just discussed. When booted
lockable hydraulic slider 571 locks, knee pivot 6 also locks.
[0110] FIG. 36 shows self-hyper-locker 36 for guaranteeing
hyper-extension at foot strike. The idea is to route closer cord B
624 around a path which passes both on the front side and back side
of folding knee pivot 6 in such a manner that the back part of the
path (between top inside post 604 and inside pulley 628) increases
faster than the front part of the path (between top outside post
602 and outside pulley 626) as tibia link 7 and thigh link 4 unfold
about knee pivot 6. By choosing a certain length of closer cord B
624, closer cord B 624 becomes taut at a particular flexion angle
as the unfolding occurs, causing closer cord B 624 to begin to pull
on closing spring 610 which acts to accelerate the unfolding,
especially if closing spring 610 is pre-loaded (which is easily
accomplished with a plug (not shown) on closer cord B 624 just
below the bottom of notched tube 608). Top outside post 602 and top
inside post 604 are fixably attached to thigh link 4. Bottom
outside post 630 and bottom inside post 632 are fixably attached to
tibia link 7--providing support for outside pulley 626 and inside
pulley 628. Notched tube 608 is attached to top outside post 602 by
reset spring 620. Closer cord B 624 is attached to notched tube 608
via closing spring 610 which is stronger than reset spring 620.
Notched tube 608 is slidably connected to thigh link 4 via
notched-tube guide 606. Pawl 612 is pivotly connected to thigh link
4 at pawl pivot 616 via pawl tab 614 (fixably attached to thigh
link 4). Pawl spring 618 bias pawl 612 to engage the notch in
notched tube 608 when it is pulled upward in swing phase by reset
spring 620.
[0111] Accordingly, FIG. 36a shows self-hyperlocker 600 in swing
phase when closer cord B 624 is slack and there is no unfolding
force--allowing the tibia link 7 to swing freely. Reset spring 620
has pulled notched tube 608 up so that pawl 612 can engage its
notch. Again, at a particular flexion angle closing spring 610
slams tibia link 7 closed as seen in FIG. 36b. Just after the joint
becomes hyper-extended, pawl bumper 622 impinges the bottom of pawl
612 causing it to disengage from the notch of notched tube 608,
thereby releasing closing spring 610 from its folding force because
notched tube 608 moves down notched-tube guide 606--shortening the
patch of closer cord B 624 (shown in FIG. 36c) and causing it to
become slack. Thus, there is no closing force later, at toe-off, to
resist folding and high kick. Self-hyperlocker 600 is called "self"
because it does not require any trigger from the foot or the hip to
work. The release of closing force is keyed to hyper-extension at
the knee pivot. Self-hyperlocker 600 can be used with simple-hinge
knee pivots or with four-bar knee pivots (in which case it only
needs to be located at one of the two knee pivots).
[0112] FIG. 37 shows a "hyper-extension bounce back" prevention
means for prevention of folding of a hyper-extending knee lock at
heel strike. Pinched bladder 640 is glued to bladder step 646 in
tibia link 7. Pinch band 624 forms a portion of pinched bladder 640
exterior to bladder step 646. And it allows only a small orifice
connecting the main body of pinched bladder 640 with elastomer
nipple 644. When tibia link 7 closes to the point where
hyper-extension of the joint begins, the bottom of thigh link 4
squeezes bladder fluid through the orifice made by pinch band 642
into elastomer nipple 646, causing it to expand. The resistance to
fluid flow through a small orifice absorbs the impact energy of the
closing of the joint so it does not bounce back open. The force
exerted by the expansion of elastomer 644 is too small to re-open
the joint when it is loaded by a runner's weight, but this force is
large enough to force the fluid back through the orifice during
swing phase when pinched bladder 640 is no longer squeezed. This is
a very cheap and simple way to eliminate bounce-back opening of the
knee joint as compared with elaborate, expensive hydraulic devices
used in conventional above-knee prostheses.
[0113] FIG. 38a shows a rear view and FIG. 38b a side view of
front/back brace leg 650 in which the pelvic coupling is made
directly behind and in front of the runner's ischial tuberosity
(buttock) rather on the side of the hip. Front hip pivot 678 is
pivotly attached to harness 3 directly above runner's leg 676 in
front, and back hip pivot 680 is pivotly attached to harness 3
directly above runner's leg 676 in back. Front and back--hip pivots
678 and 680, knee pivots 660 and 662, and thigh links 652 and
654--and knee cross link 674 form a four-bar system. Front and
back--ankle pivots 670 and 672, knee pivots 660 and 662, and ankle
links 670 and 672--and knee cross link 674 form another four-bar
system--with knee pivots 660 and 662 and knee cross link 674 being
shared between these two four-bar systems. The runner's pelvis
and/or harness 3 act as the cross link at the hip level for the
upper four-bar system, and brace foot 8 acts as the cross link at
the foot level for the lower four-bar system. These two four-bar
systems are sufficiently distant from runnier's leg 676 throughout
a stride as to not interfere with the same. Back hydraulic knee
lock 664 is rotatably connected to a back thigh link 654 and back
tibia link 668 so that when a foot trigger (not shown, but
straightforward to implement for one of ordinary skill in the art)
locks back hydraulic knee lock 664 as foot strike, flexion about
back knee pivot 662 is locked. Another knee lock could be used for
front knee pivot 660, but this is not necessary because back knee
pivot 662 is shared by both four-bar systems. That is, when back
knee pivot 662 is locked, both the above-mentioned top and bottom
four-bar systems are converted to three-bar systems, and both
structures are locked. Folding of the upper and lower four-bar
systems with respect to each other is realized as the runner's
weight leans forward. This folding can be enhanced by tethering
front and back knee pivots 660 and 662 to the runner's knee. The
runner's foot can now be coupled to brace foot 8 anywhere along the
length of the runner's foot. Front and back bows 656 and 658 store
and return impact energy, and only one of these need be used.
Finally, if the one or both knee pivots in FIG. 38 are constrained
from hyper-extending (see e.g. FIGS. 16 and 36), a separate knee
lock, such as back hydraulic knee lock 664, can be eliminated since
the "constrained hyper-extension knee lock" naturally locks at
heel-strike and naturally starts folding just before toe-off.
Having a separate knee lock allows the runner to run uphill or to
land with a more substantially pre-bent leg, but this capability is
not needed in many applications. This is even more true for a
running brace than for above-knee prostheses, since the runner's
leg is there to prevent a fall.
[0114] FIG. 39 shows front/back pack extension 690 for comfortable
and optimal pack load support. The running/walking brace shown is
front/back brace leg 650 of FIG. 38. Front pack frame 692 is
pivotly attached to the top front of front/back brace leg 650 by
pack-frame pivot 698, and back pack frame 694 is pivotly attached
to the top back of front/back brace leg 650 by pack-frame pivot
698. Pack straps 696 attach front pack 700 to front pack frame 692,
and back pack 702 to back pack frame 694. If the brace legs were
not supporting the pack weight, there would be an uncomfortably
high load on the runner's shoulders. Also, the front parts of
front/back pack extension 690 can be eliminated, in which case
runner 1 must lean forward at the waist to balance the pack.
[0115] FIG. 40 shows four-bar knee joint 704 with hyper-extension
stop 708 which prevents hyperextension of the joint. Optional
four-bar hydraulic lock 706 can be used to lock four-bar knee joint
704 and which can be triggered to lock a foot-contact in a manner
similar to that of booted lockable hydraulic slider 571 of FIG.
34.
[0116] FIG. 41 is a schematic side view of a low-eccentricity knee
joint straightener 720. It resists folding about side knee pivot 6
with only a very small force (of circle spring 728) beyond a chosen
flexion angle so that the wearer is free to high kick. As tibia
link 7 descends beyond this chosen flexion angle, low-eccentricity
knee-joint straightener 720 acts to accelerate this straightening
via close spring 724 with a force that increases proportional to
eccentricity 712 of the spring force about knee pivot 6. Thus, the
greatest straightening force acts when full straightening occurs.
The components are assembled as follows. Circle tube 730 is rigidly
attached to thigh link 4 and circle brace 732 which extends rigidly
from thigh link 4. Slide ring 726 slides along circle tube 730 and
it is connected both to close spring 724 which extends down to
connect to tibia link 7 and to circle spring 728 which extends
through circle rube to connect to its upper end. Slide ring 726 is
constrained from sliding tip and to the right at a chosen location.
Pivot stops 86 prevent hyper-extension about side knee pivot 68. In
FIG. 41a, the configuration is straight, eccentricity 202 is at a
maximum value, and the straightening force is at a maximum value.
In FIG. 41b, shin tube has folded to the point where shin-tube
extension 722 impinges slide ring 726, eccentricity 702 is very
small, and the straightening force due to close spring 724 is very
small. In FIG. 41c, shin tube 64 has folded considerably. However,
the straightening force due to close spring 724 is still very small
because slide ring 726 is forced to slide around circle tube 730 by
shin-tube extension 722 and eccentricity 702 remains very small.
There is still a very small resistance to folding due to circle
spring 730 which is much weaker than close spring 724. Again, as
straightening progresses beyond the configuration of FIG. 41b, the
straightening force increases rapidly.
[0117] This completes the discussion of the figures. Now a few
general issues will be discussed. One of the key problems discussed
in various parts of this patent is to guarantee the release of the
lock of the swing-phase length change means, which can be the
self-locking knee mechanism FIG. 9, the variable-angle knee lock of
FIG. 11, the slider of FIG. 29, or the simple slider of FIG. 32.
This lock release is necessary but not sufficient for guaranteed
folding (about the knee pivot for the hyper-extended knee locks)
which will be discussed afterward. Guaranteed lock release is
necessary because a runner can lift the brace foot prematurely,
thereby preventing a break in the loading of the lock, therefore
preventing lock release; then the runner could fall flat on her
face. For the hyper-extending design of FIG. 9, a simple spring
between thigh-link constraint 120 and tibia-link constraint 122
might suffice. If more guarantee is needed the hyperlocker
mechanisms of FIG. 28 and 36 can be utilized. Also, a four-bar
system such as that shown in FIG. 38 will naturally fold as the
runner's weight leans forward near the end of stance. For the
variable-angle knee-lock, tibia lock-release 93 of FIG. 16 can be
used if a simple spring--to push down split collar 69 with respect
to hollow shaft 62, thereby disengaging circumferential strips
78--does not suffice to release the lock at toe-off. For the slider
of FIG. 29 or the simple slider of FIG. 32, a spring to disengage
slider ratchet 532 may be sufficient to release the lock at
toe-off. If not, foot-coupling guaranteed release mechanism of FIG.
31 can be used.
[0118] Guaranteed folding (about the knee pivot for the
hyper-extended knee locks) is achieved with a heel coupling in FIG.
9, a knee tether (mentioned in the discussion of FIG. 38 although
it could be used in any of the hyper-extended knee locks), and as a
natural consequence of a forward lean in the discussion of FIG. 38
of a four-bar knee pivot. It simply means that the force exerted by
the runner on the brace leg must fold the knee pivot rather than
hyper-extend it.
[0119] In conclusion, the invention herein described comprises a
variety of passive or spring running aids--most notably an energy
efficient running aid or brace which provides optimally fast
support of a runner's impact load by virtue of the buckling load
force curve of the bucky-bow spring and by virtue of the
load-tightening body harness with minimal compliance. In addition,
the designs can also be used for walking or in conjunction with an
active power source. The spring is lightweight and features an
optimally long travel, along with an optimal constant force curve.
In the second embodiment of FIGS. 6 and 7, since a cable system
with pulleys is used, there is a "gear changing" feature, and a
single bow spring can be used for either leg. The harness achieves
a unique capability in that it provides for a uniform distribution
of impact load over a substantial portion of the runner's body,
even though the runner's body is vertical. Comfort is enhanced with
a load-tightening feature of the harness. The daunting knee-lock
problem is circumvented with a knee self-locking device of FIG. 9
which solves the other difficult problem of guaranteed knee-lock
release, and it is solved with the variable-angle knee locking
device of FIGS. 11-14 and the lock-release devices of FIGS. 16, 31,
34 and 36. This variable-angle device allows uphill running, and it
results in an effective gear changing because the spring action is
not as aligned with the thrust action when the knee pivot locks at
a more bent position. Finally, a shaped brace foot solves the
problem of leg-length asymmetry. The overall design is lightweight,
and this aspect is improved by minimizing the distill weight of the
running aid.
[0120] It should be understood that the running aid described
herein has many features which apply to robotic running as well as
to a running brace. These include the spring mechanisms for energy
return, the brace foot, and the self-locking pivot. The running aid
invention uses either the pulley-bow or the series bucky bow, as
well as the single pulley bow in the back, all can be easily
adapted to robotic running. The brace foot should be used as well
in robotic running to optimize the angles of leg/foot support while
landing and taking off for greater performance and fuel economy. A
slight adaptation would be needed to use the self-locking knee
pivot because there is no runner's foot to lift Up the heel pivot
to fold the knee pivot. Instead, a cable could be spring-loaded and
triggered by toe-off to pull on the heel pivot to unlock the knee
pivot for swing phase. And, the uphill running feature to allow the
bow to engage and the knee pivot to lock when the runner's leg
lands partially bent can also be use in robotic running. Also, the
front/back brace leg of FIG. 38 can be used for exo-skeleton
applications which are active as well as passive. And, it can be
used for above-knee prostheses and robots. Furthermore, separate
four-bar systems can be used to allow articulation in the roll
plane as well as the pitch plane.
[0121] The running aid designs herein also can be used for both
walking even though the main thrust in the development of these
designs has been for running. These running aid designs can also be
used for carrying a backpack. The backpack can simply be attached
to the pelvic rim of the harness in which case the running aid
substantially supports the load of the backpack, and the harness is
not needed--at least for support of the pack by the running brace.
Or, as just described for FIG. 39, tile front/back brace leg of
FIG. 38 can be used to support pack weight both in front of and
behind the runner via a front/back pack extension. This design
provides for improved equilibrium of the runner/pack system, and it
eliminates the uncomfortable backward force on the runner's
Shoulders resulting from pack which is only in the back.
[0122] Since the preferred spring systems described herein provide
an approximately constant force curve, they also provide for the
maximum amount of absorption and return of impact energy--given a
threshold level of force that the human body can safely tolerate.
This means that these preferred spring systems, herein called
bucky-bow springs or "series" bow springs, can be used for extreme
landing protection such as with parachute landing or jumping from
heights, and the full-body harness described herein can also be
used for these applications. It is hoped that this invention will
provide enjoyment and injury-free exercise for people who love to
run.
[0123] The above description shall not be construed as limiting the
ways in which this invention may be practiced but shall in
inclusive of many other variations that do not depart from the
broad interest and intent of the invention.
* * * * *