U.S. patent number 3,685,176 [Application Number 05/051,841] was granted by the patent office on 1972-08-22 for inflatable article of footwear.
This patent grant is currently assigned to Robert C. Bogert. Invention is credited to Marion F. Rudy.
United States Patent |
3,685,176 |
Rudy |
August 22, 1972 |
INFLATABLE ARTICLE OF FOOTWEAR
Abstract
Footwear comprising an inflatable bladder to be disposed in a
boot for embracing a person's foot, ankle and lower leg portion,
and having a plurality of intercommunicating flexible tubes adapted
to be inflated to a desired pressure, the material and hardness of
the bladder and the cross-sections of the inflated tubes being
selected to prevent relative lateral movement between the foot,
ankle and lower leg portion, while permitting restrained fore and
aft movement between such parts. A lower set of tubes bearing
against the upper portion of the foot at the ankle joint and a rear
set of tubes bearing against the Achilles' tendon region have an
inflated cross-section that permits fore and aft movement of the
leg with respect to the foot about the ankle joint to effect a
decrease in volume of one set, thereby increasing the pressure in
the tubes, and producing a corresponding increase in volume and
inflation of the other set, to exert a greater downward force
holding the bottom of the foot firmly against the heel and sole of
the boot.
Inventors: |
Rudy; Marion F. (Northridge,
CA) |
Assignee: |
Bogert; Robert C. (Woodland
Hills, CA)
|
Family
ID: |
21973695 |
Appl.
No.: |
05/051,841 |
Filed: |
July 2, 1970 |
Current U.S.
Class: |
36/71; 36/93 |
Current CPC
Class: |
A43B
5/0407 (20130101); A43B 23/07 (20130101) |
Current International
Class: |
A43B
23/00 (20060101); A43B 23/07 (20060101); A43B
5/04 (20060101); A63f 005/00 () |
Field of
Search: |
;36/2.5R,2.5AL,2.5N,71 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Lawson; Patrick D.
Claims
I claim:
1. An article of footwear comprising an inflatable bladder adapted
to be disposed within a boot to bear against areas of a wearer's
foot, said bladder including a multiplicity of adjacent chamber
portions, including a plurality of chamber portions at each side of
the foot, said multiplicity of chamber portions communicating with
each other to provide uniform unit pressure in said portions when
the bladder is inflated to exert an inward force on the foot.
2. An article of footwear as defined in claim 1; wherein said
chamber portions extend lengthwise of the wearer's foot when
disposed thereon.
3. An article of footwear comprising an inflatable bladder adapted
to be disposed within a boot to bear against areas of a wearer's
foot, said bladder including a plurality of adjacent chamber
portions communicating with each other to provide uniform unit
pressure in said portions when the bladder is inflated to exert an
inward force on the foot; said bladder being shaped for disposition
of said chamber portions upon the back, sides and top of the foot,
whereby said inflated chamber portions substantially restrain the
foot against movement relative to the boot.
4. An article of footwear as defined in claim 3; a major number of
said chamber portions extending lengthwise of the wearer's foot
when disposed thereon.
5. An article of footwear as defined in claim 1; a number of said
chamber portions being of such size and shape as to be
substantially rigid after being inflated by a fluid to normal
operating unit pressure.
6. An article of footwear comprising an inflatable bladder adapted
to be disposed within a boot to bear against areas of a wearer's
foot, said bladder including a plurality of adjacent chamber
portions communicating with each other to provide uniform unit
pressure in said portions when the bladder is inflated to exert an
inward force on the foot; a number of said chamber portions being
of such size and shape as to be substantially rigid after being
inflated by a fluid to normal operating unit pressure, other of
said chamber portions being of such size and shape as to be
deformable after being inflated by the fluid to normal operating
unit pressure.
7. An article of footwear as defined in claim 3; said chamber
portions disposed at the back of the foot along the Achilles'
tendon and at the top of the foot at the ankle joint being of such
size and shape as to be deformable after being inflated by a fluid
to normal operating unit pressure, said chamber portions at the
sides of the foot and at the top of the foot forwardly of the ankle
joint being substantially rigid after being inflated by the fluid
to normal operating unit pressure.
8. An article of footwear as defined in claim 3; a major number of
said chamber portions extending lengthwise of the wearer's foot
when disposed thereon, said chamber portions disposed at the back
of the foot along the Achilles' tendon and at the top of the foot
at the ankle joint being of such size and shape as to be deformable
after being inflated by a fluid to normal operating unit pressure,
said chamber portions at the sides of the foot and at the top of
the foot forwardly of the ankle joint being substantially rigid
after being inflated by the fluid to normal operating unit
pressure.
9. An article of footwear as defined in claim 3; a major number of
said chamber portions extending lengthwise of the wearer's foot
when disposed thereon, said chamber portions at the malleoli of the
foot being of toroidal shape.
10. An article of footwear as defined in claim 3; a major number of
said chamber portions extending lengthwise of the wearer's foot
when disposed thereon, said chamber portions at the malleoli of the
foot being of toroidal shape, a chamber portion at the navicular
bone of the foot being of toroidal shape.
11. An article of footwear comprising an inflatable bladder to be
disposed within a boot and shaped to receive a wearer's foot, said
bladder having an upper circumferential manifold tubular portion
for embracing the leg above the ankle joint and other tubular
portions communicating with and extending downwardly from said
manifold portion along the lower end of the leg and along the back,
sides and top of the foot, whereby inflation of said tubular
portions by a fluid causes said bladder to restrain movement of the
leg and foot relative to the boot.
12. An article of footwear as defined in claim 11; said tubular
portions above the ankle joint and at the sides of the foot being
of such size and shape as to be substantially rigid after being
inflated by a fluid to normal operating pressure to prevent lateral
movement of the leg and foot relative to the boot.
13. An article of footwear as defined in claim 11; said tubular
portions above the ankle joint and at the sides of the foot being
of such size and shape as to be substantially rigid after being
inflated by a fluid to normal operating pressure to prevent lateral
movement of the leg and foot relative to the boot, said portions
disposed at the back of the foot along the Achilles' tendon and at
the top of the foot at the ankle joint being of such size and shape
as to be deformable after being inflated by a fluid to normal
operating unit pressure.
14. An article of footwear as defined in claim 11; said tubular
portions above the ankle joint, at the side of the foot, and at the
top of the foot forwardly of the ankle joint being of such size and
shape as to be substantially rigid after being inflated by a fluid
to normal operating pressure to prevent lateral movement of the leg
and foot relative to the boot.
15. An article of footwear as defined in claim 11; said tubular
portions above the ankle joint, at the side of the foot, and at the
top of the foot forwardly of the ankle joint being of such size and
shape as to be substantially rigid after being inflated by a fluid
to normal operating pressure to prevent lateral movement of the leg
and foot relative to the boot, said tubular portions disposed at
the back of the foot along the Achilles' tendon and at the top of
the foot at the ankle joint being of such size and shape as to be
deformable after being inflated by a fluid to normal operating unit
pressure, said tubular portions at the lower end of the leg, at the
sides of the foot, and at the top of the foot forwardly of the
ankle joint being substantially rigid after being inflated by the
fluid to normal operating unit pressure.
16. An article of footwear as defined in claim 11; said tubular
portions above the ankle joint, at the side of the foot, and at the
top of the foot forwardly of the ankle joint being of such size and
shape as to be substantially rigid after being inflated by a fluid
to normal operating pressure to prevent lateral movement of the leg
and foot relative to the boot, said tubular portions disposed at
the back of the foot along the Achilles' tendon and at the top of
the foot at the ankle joint being of such size and shape as to be
deformable after being inflated by a fluid to normal operating unit
pressure, said tubular portions at the lower end of the leg, at the
sides of the foot, and at the top of the foot forwardly of the
ankle joint being substantially rigid after being inflated by the
fluid to normal operating unit pressure, tubular portions at the
malleoli of the foot being of toroidal shape.
17. An article of footwear as defined in claim 11; said tubular
portions above the ankle joint, at the side of the foot, and at the
top of the foot forwardly of the ankle joint being of such size and
shape as to be substantially rigid after being inflated by a fluid
to normal operating pressure to prevent lateral movement of the leg
and foot relative to the boot, said tubular portions disposed at
the back of the foot along the Achilles' tendon and at the top of
the foot at the ankle joint being of such size and shape as to be
deformable after being inflated by a fluid to normal operating unit
pressure, said tubular portions at the lower end of the leg, at the
sides of the foot, and at the top of the foot forwardly of the
ankle joint being substantially rigid after being inflated by the
fluid to normal operating unit pressure, tubular portions at the
malleoli of the foot being of toroidal shape, a tubular portion at
the navicular bone of the foot being of toroidal shape.
18. An article of footwear comprising an inflatable bladder adapted
to be disposed within a boot to bear against areas of a wearer's
foot, said bladder including a plurality of adjacent chamber
portions communicating with each other to provide uniform unit
pressure in said portions when the bladder is inflated to exert an
inward force on the foot; said bladder comprising a plurality of
elastomeric sheets adhered together at spaced regions to provide
said chamber portions between said regions.
19. An article of footwear comprising an inflatable bladder adapted
to be disposed within a boot to bear against areas of a wearer's
foot, said bladder including a plurality of adjacent chamber
portions communicating with each other to provide uniform unit
pressure in said portions when the bladder is inflated to exert an
inward force on the foot; wherein said chamber portions extend
lengthwise of the wearer's foot when disposed thereon, said bladder
comprising elastomeric sheets overlying one another and adhered
together along spaced longitudinal lines to provide said chamber
portions.
20. An article of footwear as defined in claim 11; said bladder
comprising opposed elastomeric sheets adhered together along spaced
lines to provide all of said tubular portions.
21. An article of footwear as defined in claim 11; said tubular
portions above the ankle joint, at the side of the foot, and at the
top of the foot forwardly of the ankle joint being of such size and
shape as to be substantially rigid after being inflated by a fluid
to normal operating pressure to prevent lateral movement of the leg
and foot relative to the boot, said tubular portions disposed at
the back of the foot along the Achilles' tendon and at the top of
the foot at the ankle joint being of such size and shape as to be
deformable after being inflated by a fluid to normal operating unit
pressure, said tubular portions at the lower end of the leg, at the
sides of the foot, and at the top of the foot forwardly of the
ankle joint being substantially rigid after being inflated by the
fluid to normal operating unit pressure, said bladder comprising
opposed elastomeric sheets adhered together along spaced lines to
provide all of said tubular portions.
22. An article of footwear as defined in claim 11; said tubular
portions above the ankle joint, at the side of the foot, and at the
top of the foot forwardly of the ankle joint being of such size and
shape as to be substantially rigid after being inflated by a fluid
to normal operating pressure to prevent lateral movement of the leg
and foot relative to the boot, said tubular portions disposed at
the back of the foot along the Achilles' tendon and at the top of
the foot at the ankle joint being of such size and shape as to be
deformable after being inflated by a fluid to normal operating unit
pressure, said tubular portions at the lower end of the leg, at the
sides of the foot, and at the top of the foot forwardly of the
ankle joint being substantially rigid after being inflated by the
fluid to normal operating unit pressure, tubular portions at the
malleoli of the foot being of toroidal shape, a tubular portion at
the navicular bone of the foot being of toroidal shape, said
bladder comprising opposed elastomeric sheets adhered together
along spaced lines to provide all of said tubular portions.
23. An article comprising an inflatable bladder adapted to bear
simultaneously against areas of a wearer's body and against a
restraining member, said bladder including a plurality of adjacent
chamber portions communicating with each other to provide uniform
unit pressure in said portions when the bladder is inflated to
exert an inward force against such areas, one or more of said
chamber portions being of such size and shape as to be deformable
after being inflated by a fluid to normal operating unit pressure,
one or more other chamber portions being substantially rigid after
being inflated by the fluid to said normal operating unit
pressure.
24. An article of footwear comprising an inflatable bladder adapted
to be disposed within a boot to bear against areas of a wearer's
foot, said bladder including a multiplicity of adjacent chamber
portions communicating with each other and comprising a plurality
of adjacent chamber portions disposed at the back of the foot, a
plurality of said adjacent chamber portions being located on each
side of the Achilles' tendon rearwardly of the ankle joint to
provide uniform unit pressure in said portions when the bladder is
inflated to exert an inward force on the foot.
25. An article of footwear as defined in claim 24; wherein said
adjacent chamber portions on each side of the Achilles' tendon
extend lengthwise of the wearer's foot when disposed thereon.
26. An article of footwear comprising an inflatable bladder adapted
to be disposed within a boot to bear against areas of a wearer's
foot, said bladder including a multiplicity of adjacent chamber
portions communicating with each other and comprising a plurality
of chamber portions disposed at the back of the foot on each side
of the Achilles' tendon to provide uniform unit pressure in said
portions when the bladder is inflated to exert an inward force on
the foot; said bladder comprising a plurality of elastomeric sheets
adhered together at spaced regions to provide said chamber portions
between said regions.
27. An article of footwear comprising an inflatable bladder adapted
to be disposed within the lower leg portion of a boot, said bladder
including a multiplicity of adjacent chamber portions adapted to be
disposed within the lower leg portion of the boot and communicating
with each other to provide uniform unit pressure in said portions
when the bladder is inflated, said multiplicity of chamber portions
including a plurality of chamber portions on each side of said
lower leg portion of the boot.
28. An article of footwear as defined in claim 27; wherein said
multiplicity of chamber portions extend lengthwise of the wearer's
lower leg portion when disposed thereon.
29. An article of footwear as defined in claim 27; said bladder
comprising a plurality of elastomeric sheets adhered together at
spaced regions to provide said chamber portions between said
regions.
30. An article of footwear as defined in claim 27; said
multiplicity of chamber portions being constructed and arranged to
encompass a major portion of the lower leg portion.
31. An article comprising an inflatable bladder adapted to bear
simultaneously against areas of a wearer's body and against a
restraining member, said bladder including a multiplicity of
adjacent chamber portions communicating with each other to provide
uniform unit pressure in said portions when the bladder is inflated
to exert an inward force against such areas, a first plurality of
said adjacent chamber portions being of such size and shape as to
be deformable after being inflated by a fluid to normal operating
unit pressure, a second plurality of said adjacent chamber portions
being substantially rigid after being inflated by the fluid to said
normal operating unit pressure.
32. In combination: a restraining member adapted to encompass an
area of the wearer's body; an inflatable bladder within said
restraining member and including a multiplicity of adjacent chamber
portions communicating with each other to provide uniform unit
pressure in said portions when the bladder is inflated to exert an
outward force against the restraining member and an inward force
upon the area of the wearer's body, said multiplicity of chamber
portions including a first plurality of said adjacent chamber
portions at one side of said restraining member, and a second
plurality of said adjacent chamber portions at another side of said
restraining member.
33. In a combination as defined in claim 32; said first plurality
of chamber portions being of such size and shape as to be
deformable after being inflated by a fluid to normal operating unit
pressure; said second plurality of chamber portions being of such
size and shape as to be substantially rigid after being inflated by
the fluid to said normal operating unit pressure.
Description
The present invention relates to footwear, and more particularly to
inflatable bladders insertable in boots, such as those used in
sport activities, including skiing, hiking, skating, etc., and in
the orthopedic and military fields.
Inflatable devices have been proposed for use in boots, such as in
ski boots, to insure substantial rigidity between the boot and the
foot of the wearer. Some of these inflatable boot designs employ a
number of separate, relatively large cavities inflatable to
different pressures through different valves. Such designs are
relatively complex, the inflation of a plurality of different
cavities being inconvenient. In addition, they tend to leak and do
not maintain a preset pressure level. The relatively large cavities
produce a soft spongy pressure, but do not give the desired feel
and control between the foot and the boot, the foot being able to
move laterally relative to the boot, which is a serious
disadvantage in a boot designed for skiing.
The inflatable bladder of the present invention consists of a
plurality of inflatable chambers, tubular portions or tubes of
various sizes and geometry interconnected by a manifold, so that
the unit gaseous pressure in all tubular portions or cavities will
be the same. When inflated, some of the tubular portions are rigid;
that is to say, substantially non-yielding; although others may be
made of such cross-sectional dimensions as to be changed in volume
as a result of movement of the foot, causing a reduction in
cross-sectional area of some of the tubes and an inflation of other
of the tubes, for the purpose of insuring the retention of the foot
in the desired firm position within the boot, with a restraining
force applied to the foot against movement within the boot in
desired directions, as in lateral directions. The inflatable
bladder not only provides extremely firm support and a desirable
restraining force against the foot, but further provides firm and
comfortable conformity to the irregular contour of the foot without
imposing localized pressure on the bones, foot irregularities, and
the like. The inflated bladder constantly forces the heel of the
foot into the heel of the boot, and, at the same time, grasps the
Achilles' tendon area of the foot to hold the heel of the foot in
firm comfortable conformance to the boot, producing sensitive feel
and control between the foot and, in the case of a ski boot, to the
ski secured to the boot.
The inflated bladder also pushes essentially uniformly downwardly
against the top of the foot, holding it in firm intimate contact
with the sole of the boot at all times. When produced for skiing,
the inflated bladder within the boot prevents relative lateral
movement of the foot within the boot, permitting the foot and ankle
muscles to move and flex to control forward and aft movement of the
body and of the leg, thereby providing edge control of the skis
without discomfort to the wearer.
A second collar portion of the inflatable bladder may also be
provided, including a plurality of tubes and cavities
interconnected by a manifold, or the like. Such portion, when
inflated, rigidly supports the lower portion of the leg of the
wearer. The collar portion can be provided in a ski boot to permit
its pivoting in fore and aft directions relative to the lower foot
portion, allowing the lower leg to pivot in the same directions.
This inflatable collar portion firmly and comfortable grasps the
lower leg above the ankle joint to hold the collar portion securely
around the lower leg and aligned therewith. Accordingly, portions
of the boot are free to rock back and forth, but restrained from
rocking laterally, having the effect of significantly strengthening
the ankle muscle control of the ski edgings. In a relaxed or
neutral condition, the skis are held perpendicular to the lower
legs and feet, relative lateral movement being prevented, retention
of the bottom surfaces of both skis parallel to each other being
enhanced. By enabling the skis to be held parallel, the exerting of
small and uniform degrees of edge control permits the skier to
control and guide the forward path of the skis and keep them from
crossing or moving apart, which could cause the skier to fall.
The collar portion of the inflatable bladder also strengthens the
leg muscles for fore and aft movement, requiring less muscular
strain for the skier to hold the forward leaning or "running"
position.
The inflatable bladder can be permanently affixed to the inside
surface of the boot or shoe, be attached to the insole portion, or
can be provided as a separate sock to be placed on the foot and in
a conventional boot or shoe, which would be laced or buckled in a
loose condition, the inflatable bladder then being inflated to the
desired pressure.
A further aspect of the inflatable bladder embodying the present
invention is to achieve any desired degree of rigidity between the
inner and outer surfaces of the bladder, and to provide comfortable
uniform force transfer capability between the foot and boot,
without providing high pressure points or sponginess. Heavy loads,
such as those sustained by an individual at the time of a fall, are
distributed and transferred into the boot, ankle joint and leg in a
smooth and uniform manner, eliminating severe concentrated stresses
at the top of the boot, thereby reducing the probability of injury
when the skier falls.
Another aspect of the inflatable bladder embodying the present
invention is to eliminate the need for adjustable buckle or lacing
devices in the shoe or boot, also eliminating the need for half
sizes of shoes and boots to obtain a perfect fit.
The inflatable bladder further has the advantage of eliminating the
need for massive boots in securing a perfect fit and controlled
rigidity, permitting the boot to be manufactured in more graceful,
form-fitting styles.
This invention possesses many other advantages, and has other
purposes which may be made more clearly apparent from a
consideration of a form in which it may be embodied. This form is
shown in the drawings accompanying and forming part of the present
specification. It will now be described in detail, for the purpose
of illustrating the general principles of the invention; but it is
to be understood that such detailed description is not to be taken
in a limiting sense.
Referring to the drawings:
FIG. 1 is an isometric view of a ski boot with an inflatable
bladder therein, the ski boot and bladder being in an open
condition;
FIG. 2 is an enlarged section taken along the line 2--2 on FIG.
1;
FIG. 3 is a section through a bladder inflatable gun and bladder
valve mechanism, as disclosed in FIG. 2;
FIG. 4 is an isometric view of the bladder in an inflated condition
around the foot and lower leg of a wearer disposed within a ski
boot;
FIG. 5 is an enlarged fragmentary section taken along the line 5--5
on FIG. 4;
FIG. 6 is a cross-section taken along the line 6--6 on FIG. 1;
FIG. 7 is a view similar to FIG. 6 disclosing the ski boot secured
in its closed condition;
FIG. 8 is an isometric view corresponding to FIG. 4, with the leg
portion tilted forwardly of the foot portion around the ankle
joint;
FIG. 9 is a view, in a single plane, of the inflatable bladder;
FIG. 10 is an enlarged section taken along the line 10--10 on FIG.
9;
FIG. 11 is an enlarged section taken along the line 11--11 on FIG.
9; and
FIG. 12 is a graph disclosing a plurality of curves showing the
relationship between inflation pressures and diameters of the
tubular portions of the inflatable bladder.
The specific boot or shoe illustrated in the drawings to exemplify
the invention has been particularly designed for use in skiing.
Essentially, it includes a main boot or foot portion 10 having an
upper 11 and an outsole 12 that may be integral therewith. An upper
collar portion 13 of the boot is pivotally secured to the main foot
portion 10 by suitable pivot pins 14 on opposite sides thereof
extending transversely of the collar and foot portion to permit
fore and aft rocking of the collar portion relative to the main
foot portion. The front portions of the collar and foot portion are
split, with external longitudinal ribs 15 provided on opposite
sides of the split, to permit separation or opening of the foot and
collar portions, suitable clamps 16 being secured to the collar and
foot portions at one side of the split for cooperation with the rib
15 on the opposite side of the split, for the purpose of drawing
the opposed edges 17 defining the split together when the boot
upper and the boot lower are to be closed.
Each clamp (FIGS. 6, 7) includes a body 200 pin connected to one
end of a link 201, the other end of which is connected by a hinge
pin 202 to a boot rib 15 at one side of the split. The body
includes an end retainer portion 203 adapted to fit over the rib 15
at the other side of the split and engage its outer side. The clamp
further includes an actuating arm 204 to which a bell crank lever
205 is pin connected, the intermediate heel 206 of this lever being
adapted to engage the outer surface of the boot. A release lever
arm 207 extends laterally outwardly for engagement by a person's
finger when the clamp is to be released.
The clamp device is disclosed in an open condition in FIG. 6 and in
a closed condition in FIG. 7. When the boot is to be closed, its
edges 17 are pushed toward each other and the clamp shifted about
its hinge pin 202 toward the rib 15 on the opposite side of the
split, to place the retainer portion 203 over and beyond such rib.
The actuating arm 204 is then pushed inwardly toward the shoe,
which will cause the retainer portion 203 to draw the ribs 15 and
the opposed edges 17 toward one another, until they are in the
closed relation disclosed in FIG. 7, at which time the outer pin
connecting the link 201 to the body 200 will have passed over
center, in the nature of a toggle joint, to retain the clamp in its
locked position, holding the boot closed about the foot and
leg.
Each clamp is readily released by merely pressing inwardly on the
release arm 207 of the bell crank lever, the heel 206 of which will
pivot on the shoe as a fulcrum, and push the actuating arm 204 in
an outward direction, the link 201 pivoting about the hinge pin to
shift the retainer portion 203 away from the rib 15 which it
engages. The clamp is released when the link 201 swings about the
hinge pin 202 and passes over center, in the manner of a toggle
joint.
The ribs 15 and clamps 16, by themselves, form no part of the
invention claimed in the present case. It will be appreciated that
other fastening devices can be used, such as adjustable buckles or
laces.
The foot portion of the boot has the usual insole 18, that may be
suitably affixed to the outsole 12, or which may be constituted as
a separate member, as illustrated.
An inflatable bladder 20, made of a suitable elastomeric material,
is adapted to be disposed around the foot, ankle and lower leg
portions of the wearer, for supporting such portions by exerting a
holding force thereon and against the confining foot and collar
portions 10, 13 of the shoe. A developed view of the inflatable
bladder is illustrated in FIG. 9. It comprises two plies 100, 101
of elastomeric sheet material, such as a non-porous, ether base,
polyurethane sheeting, that is highly resistant to moisture
degradation, extremely tough, and puncture resisting. Essentially,
the inflatable bladder 20 is a sock-like member having a plurality
of inflatable chambers, cavities or tubular portions formed between
the two sheets of material interconnected by a manifold 21 to
provide uniform fluid pressure in all regions of the bladder when
inflated. As disclosed, the two sheets of material are adhered to
one another along weld lines 22 and points 23 spaced from one
another, to provide a plurality of tubular chambers 24, 25, 26, 27,
28, 29, 30, extending along, or disposed at, different portions of
the foot, ankle joint and lower portion of the leg.
The bladder includes the upper, circumferential manifold 21
communicating with the upper ends of a plurality of longitudinal
tubes 24 extending downwardly from the manifold along the lower
portion of the leg toward the toes T of the foot. The bladder 20,
when placed around the wearer's foot, ankle portion and lower leg,
has a forward edge 31 at the lower end of the tubes 27, 28
terminating immediately behind the toes, the sole of the foot
bearing against the insole 18, the bottom of the heel of the foot
also bearing against the insole.
The type of thickness of the sheet material used, and the
cross-sectional sizes of the tubes and cavities 24 to 28 (excluding
two portions 29, 30 above the ankle and at the Achilles' tendon)
are such that when the bladder is inflated to the desired pressure,
such tubes and cavities will assume a substantially circular
cross-sectional shape and will be rigid, resisting deformation even
under comparatively high loads placed upon them by the wearer.
However, the cross-sections of the tubes 29 above the ankle joint
and of the Achilles' tendon tubes 30 are such that they can deform;
that is, inflate and deflate so as to change the pressure area
acting on the upper foot portion of the ankle joint, or the
pressure area acting against the Achilles' tendon portion of the
foot, as explained hereinbelow. Some of the tubes 24 at the sides
of the lower portion of the leg open into intercommunicating
concentric toroidal tubes or cavities 25 adapted to embrace the
medial malleolus and lateral malleolus of the foot. Longitudinal
tube portions below the inner or medial malleolus communicate with
a toroidal tube 26 adapted to embrace the navicular region of the
foot.
If desired, the side portions 32 of the bladder may be disposed
under the side margins 33 of the insole and suitably glued or
otherwise adhered thereto. However, a forward portion 31 of the
bladder and the heel portion 34 below the Achilles' tendon area 30
are open, allowing the toes to bear, through the sock of the
wearer, against the insole 18, and the heel to bear, through the
sock of the wearer, against the underlying portion of the
insole.
It is to be noted that all of the tubes and cavities communicate
with one another, the upper ends of the tubes 24 opening into the
manifold 21. Inflation of the bladder can be accomplished through a
valve 40 opening into the manifold 21, or, as specifically
illustrated, into any one of the tubes 24, such as a rear tube
adjacent to the manifold. A valve body 41 is secured to an
elastomer support plate 42 suitably attached to and sealed with the
inner surface of the outer layer 100 of one of the tubes, the inner
part of the valve body having a circumferential groove 43 in which
the plate is received. The valve body has a central outer passage
44 and a pierced inner passage portion 45 communicating with the
interior of the tube, the elastomeric material of the valve
inherently constricting and normally retaining the pierced passage
portion 45 closed. The valve body 41 extends through an enlarged
rear opening 46 in the boot collar 13 for reception of a suitable
inflating and deflating gun 47a.
Inflation and deflation of the bladder can be accomplished in a
known manner through use of a suitable needle 47 having a central
passage 48 therein closed at its inner end 49, where a side port 50
communicates with the needle passage. The needle also has a
deflating port 51 spaced substantially from the other port 50. The
outer end of the needle is threaded into a gun case or housing 52
which has an outlet 53 opening into a transverse passage 54
surrounded by a valve seat 55. A transversely located valve stem 56
is slidable laterally in the transverse passage 54, an outer
enlarged portion 57 of the valve stem engaging a suitable side seal
58 mounted in the housing to prevent fluid leakage along the valve
stem. A reduced diameter portion 59 of the valve stem is suitably
secured to a valve head 60 carrying a gasket seal 61 adapted to
engage the valve seat 55 when the passage 53, 54 is to be closed. A
helical compression spring 62 bears against the housing and a
button 63 at the outer end of the valve stem to normally retain the
valve head engaged with its seat. Depression of the button against
the force of the spring shifts the valve head from its seat,
allowing gas under pressure to flow into the transverse passage 54
and the outlet passage 53.
The gas under pressure may be provided from a suitable source. As
shown, a carbon dioxide cartridge 64 is contained within a suitable
chamber 65 in the housing 52, which is closed by an end cap 66
threadedly secured to the housing, the end cap bearing against the
cartridge for the purpose of pressing its forward end wall 67
against the tapered or pointed end 68 of a needle 69 disposed
within a socket 70 in the housing. A suitable side seal 71 carried
by the housing makes a slidable seal with the cylindrical neck
portion 72 of the cartridge, such that partial unthreading of the
cap 66, after the end wall 67 of the cartridge has been pierced by
the needle point 68, will retract such end wall from the tapered
point and permit the gas under pressure in the cartridge to flow
through a housing inlet passage 73 into a housing cavity 74
communicating with the transverse passage 54 when the valve is
open. When a cartridge is to be replaced, further unthreading of
the cap 66, but prior to its complete unthreading from the housing
52, will allow the neck 72 of the cartridge to move off the side
seal ring 71, permitting any gas under pressure in the cartridge to
exhaust through vent ports 75 in the housing to atmosphere. After
this occurs, the cap 66 can be completely unthreaded from the
housing in a safe manner for replacement of the cartridge 64.
The hollow needle 47 is inserted in the valve passage 44, 45, a
reduced diameter forward housing portion 76 moving over the valve
41 and within the boot opening 46. The tapered end 49 of the needle
will engage the pierced passage portion 45 and spread it apart to
locate the inner port 50 against a reinforcing pad 77 secured to
the opposed wall 101 of a tube 24. When the needle is fully
inserted within the valve, the inner port 50 is in open
communication with the tube, but the deflating port 51 is confined
within the elastomer valve body 41, which closes it. Accordingly,
when the button 63 is depressed to open the housing valve, the
gaseous medium will flow through the hollow needle into the tube
24, which is in communication with all other tubes and cavities of
the bladder, to inflate the bladder to the desired pressure, after
which the needle 47 is withdrawn completely from the valve, the
pierced portion 45 of the latter inherently constricting to its
closed condition.
It is apparent that the bladder 20 will first be placed around the
foot, ankle and lower leg portion of the wearer and located in the
boot, after which the boot will be closed through use of the clamps
16, preferably before inflation of the bladder to the desired
pressure occurs.
With the tubes and cavities of the bladder inflated to the desired
pressure, they achieve an operationally rigid state, unless the
unit pressure within certain of the tubes is increased beyond a
predetermined point to effect their deformation. As described
above, the cross-sections of all tubes and the manifold, with the
exception of the Achilles' tendon tubes 30 and the tube portions 29
above the ankle joint, are such that the predetermined maximum
internal pressure is not exceeded. During skiing operations,
however, fore and aft movements of the leg about the ankle joint as
a pivot can produce sufficient deformation of the tubes 29 above
the ankle, or the Achilles' tendon tubes 30, as to change their
volume, thereby effecting increase in the unit gas pressure within
the bladder. The inflation and deflation of the tubes 29 above the
ankle and of the Achilles' tendon tubes 30 are taken advantage of,
since it will increase the area of such tubes bearing upon the
foot, holding the foot firmly downwardly against the sole of the
boot. Such fore and aft movement is permitted by the pivoting of
the collar portion 13 of the boot with respect to the foot portion
10. However, the other tubes and cavities 24 to 28 remain
undeformed and rigid, holding the foot in laterally rigid relation
within the boot, preventing relative lateral movement of the foot
therewithin.
The graph in FIG. 12 discloses the relationship between the unit
pressure within an elastomeric tube and the diameters of the tube,
the tube wall thickness being the same. As shown in curves 200 and
201, each elastomer tube or cavity will change from its deflated
condition to an inflated condition under relatively low pressure
300, but will then retain substantially the same diameter as the
pressure increases up to a certain value, as indicated by the
points P1 and P2 in the chart. Further increase in pressure will
effect inflation and expansion of the tubular diameter (see curve
201), the wall thickness becoming thinner and thereby causing the
pressure to drop as the diameter increases.
Thus, in the chart, it is evident that over a substantial pressure
range (1 to 24 psi in curve 200; 1 to 11 psi in curve 201) a tube
remains essentially constant in diameter, each tube depicted in the
curves being essentially rigid in its particular range. Bladders
made in accordance with the present invention have had sheet or
wall thicknesses of from 0.010 to 0.020 inches, the pressure at
which the bladder has been inflated being from about 8 to 16 psi,
depending upon the desires of the wearer to secure a firm and
comfortable retention of the foot and lower leg in the boot. With
such pressure, all tubes and cavities will be rigid. The diameters
of the Achilles' tendon tubes 30 and the tubes 29 above the ankle
have been made greater than the other tubes, so that a change in
pressure, as a result of fore and aft movement, can effect
expansion and contraction of the tubes 29 and 30 to exert the
desired increased downward restraining force on portions of the
foot at the heel and forwardly of the ankle. By having the chambers
or cavities 29, 30 above the ankle and in the Achilles' tendon
region operating at near their elastic deformation limit P2,
localized forces in one of these areas can cause control pressure
migration of the other area. When the skier bends severely
forwardly in the avante position, the forward high stress tubes or
cavities 29 are partially collapsed, which increases the internal
pressure of the bladder. This has no effect on the rigid tubes and
cavities 21, 24 to 28 (curve 200), but such higher internal
pressure in the Achilles' tendon area tubes 30 at the heel causes
them to elastically expand and create an increased downward and
inward force to more firmly hold the heel of the foot down into the
heel of the boot. At the same time, the heel would be attempting to
lift out of the boot, increasing the pressure in the Achilles'
tendon tubes, such increased pressure feeding back to the forward
ankle tubes 29 to keep such tubes from collapsing.
In the event that a reverse skiing technique is employed, as by a
skiing champion, of leaning backwards, the tubes 29 above the ankle
and the Achilles' tendon tubes 30 would operate in the opposite
manner to that described above to press the sole and heel of the
foot more firmly against the sole of the boot.
One manner of producing the inflatable bladder 20 is to provide two
sheets of transparent material of the required thickness and
hardness. Heat absorbent opaque material is then placed on one
sheet of material along the desired lines 22 and points 23 of
fusion or adherence of the sheets of material to one another to
form the intervening tubes and cavities 21, 24 to 30, after which
the other sheet of material would be placed thereover, the valve 40
and plates 42, 77 having previously been located and mounted in
place. This sandwich is then subjected to visible and infra-red
radiation energy, such radiation passing through the transparent
portions of the sheets without effecting their heating
substantially but being absorbed and converted to thermal energy
along the locations of the opaque material, heating the sheets of
material along such opaque regions 22 to the degree at which they
fuse or weld securely and in leakproof fashion to one another. The
bladder structure thus formed can then be trimmed to the desired
shape, such as illustrated in FIG. 9.
As described above, the inflated bladder 20 can then be formed into
a sock-like member, with the forward edges 17a, 17a separated and
the lower margins 32 underlying and adhered to the insole 18 of the
boot. The bladder and insole are then placed within the boot, the
side edges 17a being in substantial alignment with the side edges
17 of the boot. The wearer then inserts his foot into the liner and
boot, locking the boot through aid of the clamps 16. The bladder 20
is then inflated to the appropriate pressure to form the rigid
tubes and cavities 24 to 28 and the normally rigid Achilles' tendon
tube portions 30 and forward ankle tubes 29, which, however, as
described above, can contract and inflate in a controlled fashion
under the fore and aft movement of the wearer's leg.
If desired, the inner layer 101 of sheet material can be covered
with a layer of suitable resilient material 110, such as a cellular
polyurethane, readily yieldable and comformable foam, which, in
turn, is covered by an inner liner 111 of lamb's wool, or the like.
With such intervening layers of material between the inflatable
bladder 20 and the sock on the person's foot, comfort and
conformance to the foot, ankle and lower leg portion are
achieved.
It is thus apparent that an inflatable bladder has been provided
for use within a boot that gives controlled support to the leg,
ankle and foot of the wearer. More specifically, relative lateral
motion between such parts and the encompassing boot and the ski
attached thereto in a lateral direction may be prevented, while
controlled fore and aft movement of the leg is secured without
permitting the sole and heel of the foot to lift from the sole of
the boot.
It is to be noted that the major number of tubes run lengthwise of
the leg and foot. Accordingly, when inflated, the pressure applied
by the tubes to the foot cannot arrest or materially restrict the
arteries, veins and blood vessels feeding various regions of the
leg, ankle and foot.
Deflation of the bladder, to permit removal of the foot from the
boot, can occur readily by inserting the hollow needle 47 through
the valve passages 44, 45 with the inner port 50 extending into a
tube 24 and with the deflating port 51 located externally of the
valve body 41, such that the gas in the bladder can exhaust through
the hollow tube 47 to the exterior of the valve body 41, and, if
the cartridge gun 52 is used, exhausting through housing ports 76a
to the atmosphere.
With the bladder in its substantially flat condition, as disclosed
in FIG. 9, its inflation causes it to inherently assume a compound
curved shape conforming generally to the shape of the foot and
lower leg of the wearer. This result is believed to be due to the
longitudinal and lateral arrangement of the tubes that result in
different extents of cross-wise contraction of the bladder from top
to bottom as it is inflated.
* * * * *