U.S. patent number 3,773,320 [Application Number 05/202,831] was granted by the patent office on 1973-11-20 for pogo stick with adjustable spring bias.
Invention is credited to Arthur H. Moore, David Samiran.
United States Patent |
3,773,320 |
Samiran , et al. |
November 20, 1973 |
POGO STICK WITH ADJUSTABLE SPRING BIAS
Abstract
The specification discloses a pogo stick in which the spring is
adjustable and which includes a latch which will hold the stick in
collapsed position and which can be selectively released to permit
operation of the stick. The spring can be adjusted manually or
automatically.
Inventors: |
Samiran; David (Westfield,
MA), Moore; Arthur H. (Westfield, MA) |
Family
ID: |
22751443 |
Appl.
No.: |
05/202,831 |
Filed: |
November 29, 1971 |
Current U.S.
Class: |
482/77;
267/177 |
Current CPC
Class: |
A63B
25/08 (20130101) |
Current International
Class: |
A63B
25/08 (20060101); A63B 25/00 (20060101); A63b
025/08 () |
Field of
Search: |
;272/57E ;135/64
;267/177 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Oechsle; Anton O.
Claims
What is claimed is:
1. A pogo stick comprising, in combination, an upper tubular member
having hand graspable means on the upper end and tiltable foot
engageable means on the lower end, a lower tubular member having
ground engaging means on the lower end and having the upper end
extending into the lower end of said upper tubular member in
slidable telescopic relation thereto, a spring in said upper
tubular member bearing axially between said tubular members and
urging the tubular members toward extended positions, adjusting
means for adjusting the bias exerted by said spring on said tubular
members, said adjustment means including a slidable plate mounted
in the upper tubular member and forming a bearing for the adjacent
end of said spring, an axial screw rotatably but nonaxially movable
connected at one end to one of said tubular members and threadedly
engaging said plate, means for preventing rotation of said slidable
plate within said upper tubular member, said rotation preventing
means including a spring disposed in a groove in said plate in such
manner as to engage the interior of the upper tubular member in
such manner as to prevent rotation of the plate and actuating means
for rotating said screw to adjust said slidable plate axially in
said upper tubular member and thereby adjust the bias of said
spring on said tubular members.
2. A pogo stick according to claim 1 wherein the actuating means
includes manual means connected to said screw and carried by said
upper tubular member for rotating the screw relative to said
slidable plate.
3. A pogo stick according to claim 2 in which said manual means
includes means extending through said hand graspable means and
operatively connected to said screw for selectively rotating said
screw and for permitting said screw to rotate relative to said hand
graspable means.
4. A pogo stick according to claim 1 wherein the actuating means
includes ratchet drive means connected to said screw and responsive
to relative axial movement of said tubular members for rotating
said screw relative to said slidable plate.
5. A pogo stick according to claim 4 which includes slip clutch
means in the connection of said drive means to said screw and
slipable at a predetermined torque.
6. A pogo stick according to claim 4 in which said drive means is
reversible.
7. A pogo stick according to claim 4 in which said drive means
includes means for selective adjustment thereof into ineffective
position and into position to drive said screw in either
direction.
8. A pogo stick according to claim 4 in which said drive means
includes an axially extending spiral strip connected at one end to
the end of said screw opposite the end thereof connected to said
one member, an element having a slot engaged by said spiral strip
and nonaxially moveably connected to the other of said members, and
a one-way clutch connecting said element and the other of said
members.
9. A pogo stick according to claim 8 in which said clutch is
reversible and includes a selector adjustable into a position for
each drive direction of said clutch and into a position wherein
said clutch is ineffective in both directions.
10. A pogo stick according to claim 9 in which said slip clutch
means is interposed in the connection of said strip to said
screw.
11. A pogo stick according to claim 1 which includes latch means
selectively operable by tilting said foot means for latching said
upper and lower members together in a predetermined position near
the position of maximum telescopic engagement thereof.
12. A pogo stick according to claim 11 in which said latch means
comprises a spring biased plunger on said lower member and an
aperture in said upper member engageable by the plunger, a spring
arm having an element on one end engageable with said plunger to
dislodge the plunger from the aperture, a shaft connected to the
other end of said arm and having said foot engageable means
thereon, said shaft being rotatably supported on said upper
member.
13. A pogo stick comprising: an upper tubular member having hand
graspable means on the upper end and foot engageable means on the
lower end, a lower member having ground engaging means on the lower
end and having the upper end extending into the lower end of said
upper member in slidable telescopic relation thereto, a spring
extending axially in said upper member, a plate non-rotatably but
recipocablly mounted in said upper member and engaging one end of
said spring, a ratchet assembly engaging the other end of said
spring, said ratchet assembly having a first nonrotatable part and
a second part rotatable on the first part and cooperating elements
of a ratchet on said parts, said second part having a diametral
slit therein, a screw extending axially of said upper member and
threadedly engaging said plate, one end of said screw being
rotatably but nonaxially moveably connected to one of said upper
and lower members and said first part of said ratchet assembly
being fixed to the other of said members, a spiral strip having one
end reciprocably but nonrotatively engaging said slit in said
second part of said ratchet assembly and means drivingly connecting
the other end of said strip to the free end of said screw.
14. A pogo stick according to claim 13 which includes means
moveable on said upper member and operable to adjust said elements
of a ratchet relatively to permit free rotation of said second part
on said first part in both directions or to permit free rotation of
said second part on said first part in a respective direction while
preventing rotation thereof in the opposite direction.
15. A pogo stick according to claim 13 which includes means
selectively operable for manually rotating said screw.
16. A pogo stick according to claim 13 which includes latch means
selectively operable for latching said upper and lower members
together in a predetermined position near the position of maximum
telescopic engagement thereof.
17. A pogo stick according to claim 16 in which said latch means
comprises a spring biased plunger on said lower member and an
aperture in said upper member engageable by the plunger, a spring
arm having an element on one end engageable with said plunger to
dislodge the plunger from the aperture, a shaft connected to the
other end of said arm and having said foot engageable means
thereon, said shaft being rotatably supported on said upper
member.
18. A pogo stick according to claim 17 in which said foot
engageable means comprise foot rests pivotally mounted on the ends
of said shaft for movement between horizontal working positions and
vertical idle positions.
19. A pogo stick according to claim 17 which includes a further
spring urging said spring arm toward ineffective position, and
adjustable means operatively engageable with said spring arm to
move said spring arm into effective plunger dislodging
position.
20. A pogo stick according to claim 13 which includes cooperating
elements of abutment means on said upper and lower members to limit
the extended position thereof.
21. A pogo stick according to claim 13 which includes means
preventing relative rotation of said members.
Description
The present invention relates to pogo sticks, and is particularly
concerned with an improved pogo stick construction in which the
spring force acting on the telescopic members making up the pogo
stick can be adjusted and which includes a latch for holding the
pogo stick in collapsed condition.
Pogo sticks are, of course, well known and comprise an upper
member, which is tubular, having a hand graspable portion at the
upper end and having foot engaging portions at the lower end.
Telescopically and slidably fitted into the lower end of the upper
member is a lower member having a ground engaging element at the
lower end and with a spring being provided acting axially between
the tubular members.
The present invention is concerned with a pogo stick of the general
nature referred to above except that the stick includes additional
devices for making the stick more adaptable to individuals of
different weight and for adapting the stick to different desired
operating characteristics and also for making the stick simpler to
use.
Accordingly, a primary objective of the present invention is the
provision of a pogo stick in which the spring portion acting on the
telescoping members of the stick is adjustable.
Another object of the invention is the provision of a pogo stick
with a biasing spring therein, the bias of which can be adjusted
either manually or automatically as the stick operates.
A further object of the invention is the provision of a pogo stick
which can be latched in collapsed position thereby making the stick
relatively easy to use.
These and other objects and advantages of the present invention
will become more apparent upon reference to the following detailed
specification taken in connection with the accompanying drawings in
which:
FIG. 1 is an elevational view showing a pogo stick constructed
according to the present invention;
FIG. 2A is a vertical section taken on line 2--2 of FIG. 1 of the
upper portion of the stick and drawn at enlarged scale;
FIG. 2B is a vertical section taken on line 2--2 of FIG. 1 of the
lower portion of the stick and drawn at enlarged scale;
FIG. 3 is a plan sectional view on line 3--3 of FIG. 2A;
FIG. 4 is a side elevational view of the ratchet assembly of FIG.
3;
FIG. 5 is a vertical section through a slip clutch employed in the
structure;
FIG. 6 is a side view of a plate forming a part of the structure of
FIG. 2;
FIGS. 7A and 7B are views like FIGS. 2A and 2B, but show a modified
construction;
FIG. 8 is a fragmentary view showing a modification;
FIG. 9 is a fragmentary view showing the stick in the compressed
and locked position; and
FIG. 10 is a fragmentary view showing the stick in the compressed
position but being unlocked.
BRIEF SUMMARY OF THE INVENTION
According to the present invention, a pogo stick structure is
provided which consists of an upper member, preferably tubular,
having a hand grip at the upper end and foot rests at the lower end
and a lower member slidably telescoping into the lower end of the
upper member and having a ground engaging pad on the lower end. A
spring in the upper member bears axially between the members and
urges the members toward extended position.
At least one end of the spring bears on a plate which is, in turn,
engaged by an axial screw so that rotation of the screw will adjust
the plate axially and thereby adjust the bias of the spring.
A connection with the screw permits manual rotation thereof and
there may be, furthermore, an automatic drive for the screw which
operates in response to relative telescopic movements of the lower
and upper members and which is connected with the screw via a
reversible clutch and a slip clutch.
For making the stick easy, and safe, to use, a latch is provided
which latches the members together in a position of maximum
telescopic engagement and is arranged to be operated into effective
and ineffective positions in response to tilting of the pogo stick
when the full weight of the user is supported on the foot rests of
the stick.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings somewhat more in detail, FIG. 1 is a
small elevational view showing a pogo stick according to the
present invention and which consists of an upper tubular member 10
having a hand grip or hand graspable element 12 on the upper end
and foot engageable means 14 on the lower end. The foot engageable
means comprises a bracket 16 fixed to a heavy tubular member 17
fixed to and forming the lower end part of tubular member 10 and
foot rests 18 pivotally mounted thereon for movement between folded
down horizontal working positions and folded up vertical idle
positions.
Extending upwardly into the lower end of upper tubular member 10 is
a lower member 20, which may also be at least partially tubular,
and which at the lower end has a ground engaging pad 22 thereon.
The underside of pad 22 is cut off at an angle so as to diverge
from the horizontal in a direction away from the user of the
stick.
Inside tubular member 10, as will be seen in FIG. 2, is a
compression spring 24 which at its lower end bears on a plate 26
nonrotatably mounted in the upper tubular member 10. At its upper
end, spring 24 bears on nonrotatable outer part 28 of a ratchet
drive, or clutch, to be described hereinafter.
An axial screw 30 is provided in member 10 which threadedly engages
plate 26. The screw at its lower end is fixed to nuts 31 which are
rotatably retained on the upper end of lower member 20 by a cap 33.
The upper end of member 20 also has a shoulder 35 thereon which
engages the upper end of tubular member 17 when the stick is in
fully extended position.
At its upper end, screw 30 has connected thereto one element of a
slip clutch 34, the other element of which is connected to the
lower end of an axially extending spiral strip 36, the upper end of
which extends into the inner part 29 of the aforementioned ratchet
drive, or one way clutch, which also comprises the aforementioned
outer part 28.
As will become apparent hereinafter, the ratchet drive, or one way
clutch, is reversible and in response to relative reciprocation of
members 10 and 20, will cause strip 36 to rotate in one direction
or the other, or to take no rotation, as members 10 and 20
reciprocate relatively. Any such rotation of strip 36 is imparted
to screw 36 via slip clutch 34 and this will cause adjustment of
plate 26 in one axial direction or the other and thereby change the
bias of spring 24 on members 10 and 20.
The foot rests 18 are carried on a shaft 19 which is tiltable in
the support bracket 21 which carries the shaft and which bracket is
secured to one side of member 17, as by the U bolt arrangement
23.
Bracket 21 and member 17 define a longitudinal cavity in which a
spring blade 38 is disposed with the upper end carrying a button 40
and with the lower end connected to shaft 19. Button 40 is disposed
adjacent an aperture, or slot 46, formed in tubular element 41
which is fixed to member 17 and these form a part of member 10 and
slidably receives member 20. Aperture 46 is adapted for receiving
the end of a latch plunger 48 nonrotatably but reciprocably mounted
in a transverse bore in member 20 and biased axially in a direction
toward aperture 46 by a spring 50.
Under one condition, when member 10 is moved downwardly toward its
lowermost position, as shown in FIGS. 9 and 10, plunger 48 will
engage in slot or aperture 46 and lock members 10 to 20 in
collapsed condition of the pogo stick. However, upon tilting the
foot rests 18, and which requires the full weight of the user, to
rotate shaft 19, or by inclining the stick toward the user while
holding the foot rests against rotation by the weight of the user,
and with the stick fully collapsed, the button 40 will push plunger
48 out of aperture 46 and thereby release members 10 and 20 for
relative reciprocation.
So long as the stick is maintained in a substantially vertical
position, the plunger 48 will be prevented from reentering aperture
46 but on inclining the stick away from the user, the plunger will
enter the aperture when the stick is collapsed and latch members 10
and 20 together.
The provision of the latch makes it quite simple to place the stick
in operation as opposed to pogo sticks according to the prior art
which were normally in extended position when placed in use.
It will be noted that plunger 48 has an annular groove 52 therein
near the outer edge which engages aperture 46 in tubular element 41
whereby the latch is retained in latching position until released
therefrom by placing the full weight of the user on the foot rests
on upper member 10 while simultaneously tilting the stick toward
the user.
The end of plunger 48 that extends through aperture 46 is longer
below center than above center. The latch arrangement forms a
safety feature because a user must be of sufficient height to
release the latch before the stick can be used.
Relative rotation between members 10 and 20 can be prevented as by
dog 54 on member 10 which engages axial slot 56 in member 20.
Inner part 29 of the ratchet drive has a tubular extension 60
extending axially through hand grip 12 and slidably and tiltably
but nonrotatably connected to the upper end thereof is a crank 62
rotatably connected to cap 64 threaded into and forming the upper
end of hand grip 12. By unthreading cap 64, crank 62 can be pulled
out and tilted about the axis of connecting pin 66 and then
utilized for rotating tubular extension 60 and inner part 29 of the
one-way clutch thereby to adjust screw 30 manually.
Inasmuch as crank 62 is freely rotatable in cap 64, the provision
of the crank on tubular extension 60 does not in any way interfere
with the operation of the one-way clutch when the stick is in use
and cap 64 is threaded into hand grip 12.
At the bottom of hand grip 12 is an adjusting element 68 having a
neutral position wherein inner part 29 of the ratchet drive is
freely rotatable in both directions. Adjusting element 68 has two
adjusted positions in each of which the inner part 29 of the
ratchet drive is restrained against rotation in a respective
direction so that screw 30 can either be selectively driven in one
rotation or the other during operation of the stick. Element 68 is
secured by screws 69 to a ring 71 rotatable on outer part 28 of the
one-way, or reversible, clutch and which is fixed to bottom of
handle 12. Tubular member 10 is seated circumferentially to permit
element 68 and part 28 to rotate together with screws 69.
The connection between outer and inner parts 28 and 29 respectively
of the one-way clutch is shown at FIGS. 3 and 4. It will be noted
in FIGS. 3 and 4 that inner part 29 comprises ratchet teeth 70
about the periphery thereof whereas outer part 28 has pivotally
mounted therein a two armed ratchet lever 72. The ratchet lever has
angularly disposed outer faces 74 thereon engaged by a spring blade
76. Spring blade 76 is connected with ring 71 attached to adjusting
element 68 by screws 69 so as to be rotated in response to angular
adjustment of adjusting element 68.
Two-arm lever 72 can, thus, be held in its FIG. 3 position to
permit free rotation of inner part 29 in both directions or it can
be adjusted into position wherein either of the ends of the arms of
lever 72 engage the periphery of inner part 29 so as to ratchet
over teeth 70 in a respective direction of rotation of part 29
while preventing rotation of part 29 in the opposite direction.
The slip clutch 34 is shown more in detail in FIG. 5 and will be
seen to comprise an upper element 80 adapted for connection to the
lower end of the spiral strip and a lower element 82 adapted for
being threaded on the upper end of screw 30 and fixed in place by a
lock nut 83.
Engaging the lower end of element 80 is a friction disc 84 which
also engages a disc 86 nonrotatably connected by pins 88 with upper
tubular part 90 of lower element 82. A cup 91 extends into a cavity
in the end of screw 30 and has a flange engaging the end of the
screw. A spring 92 in cup 91 urges disc 86 upwardly so friction
disc 84 will predetermine the torque at which the slip coupling
will slip.
Upper element 80 is axially located in part 90 as by pin means 94
which connect collar 95 to part 90. Collar 95 is rotatable on
element 80 so as not to interfere with the operation of the slip
coupling.
The nonrotatability of the plate 26 in tubular member 10 is
effected by the arrangement shown in FIG. 6, which will show that
plate 26 is formed with an annular groove 100 in which is seated a
coil spring 102 which consists of just under two convolutions and
which is notched between the opposed ends of the convolutions and
is held against rotation in groove 100 by a lock plate 104. Plate
26, it will be appreciated, is a nut which is held against rotation
without the use of a key and slot.
By this arrangement, if the plate 26 tends to turn in either
direction in member 10, one convolution of the spring 102 will
expand and bind in member 10 and thereby prevent the said rotation.
The spring, at least near the ends, presses against the inside of
member 10 and produces the aforesaid action. The spring arrangement
thus permits free axial movement of plate 26 in member 10, but
prevents any substantial rotation thereof in either direction in
member 10.
From the foregoing, it will be apparent that the bias of spring 24
in the stick can readily be adjusted manually to any desired degree
and that, furthermore, by availing of the one-way clutch provided,
the bias of the spring can be caused to increase or decrease during
operation of the stick due to the reciprocation of the spiral strip
in the one-way clutch. Also, by setting the selector element for
the clutch in a neutral position, adjustment of the spring during
operation of the stick can be prevented.
The pogo stick shown in FIG. 7 is substantially the same as that
shown in FIG. 2 except that certain parts are inverted.
In FIG. 7, the upper tubular member 120 has a block 122 fixed
therein to which hand grip 124 is connected. Block 122 rotatably
but nonaxially moveably supports the upper end of screw 126.
Slidably mounted on an extension of screw 126 at the upper end is a
drive tube 128 having a crank 130 pinned thereto which can be drawn
outwardly at the top of the handle by unthreading cap 132. When the
crank is drawn outwardly from the handle, it can be tilted over and
employed for rotating the screw, but when cap 132 is in its FIG. 7
position, crank 130 does not interfere with rotation of the
screw.
The plate 134, nonrotatable in upper member 120 and threadedly
engaged by the screw, is in the upper end of tubular member 120.
The lower end of the screw is connected by a slip clutch 136 with
the upper end of spiral strip 138 that extends reciprocably but
nonrotatably through inner part 140 of a ratchet assembly that
includes a nonrotatable outer part 142 fixed to the upper end of
lower member 144 of the stick assembly.
A selector member 146 is rotatably mounted on upper member 120 in
the range of the ratchet assembly and is operable for adjusting the
ratchet assembly for opposite directions of drive and into a
neutral position. Member 146 carries a plunger 147 biased outwardly
by a spring 149. By pressing plunger 147 inwardly, it will engage a
hole in the ring 151 and, due to a circumferential slot in tubular
member 120, ring 151 can be rotated so the spring finger 153
thereon can adjust clutch pawl 155. In all other respects, the
assembly of FIG. 7 is the same as that of FIG. 2 and operates in
the same manner and, accordingly, no description thereof is
given.
The modification of FIG. 8 pertains to the operation of the latch
which holds the parts of the stick in collapsed position. In FIG.
8, the lower part 150 of the stick, as before, carries a latch
plunger 152 adapted to engage an aperture 154 in a tubular element
forming a part of the upper member of the stick assembly. The
button 156 on the end of spring arm 158 is moveable axially of
aperture 154 to permit lock plunger 152 to enter the aperture or to
push it therefrom.
Arm 158 is connected with shaft 160 on which the foot rests are
mounted so as to be rotated by the foot rests. In the modification
of FIG. 8, an additional spring 162 is provided between arm 158 and
the side of the cavity in which arm 158 is disposed.
This additional spring 162 normally biases arm 158 so that it holds
button 156 in ineffective position, with a greater force than the
previous modification. However, an adjusting screw 164 is provided
which, upon being threaded inwardly, will push arm 158 toward
aperture 154 and position button 156 so that it will prevent
locking plunger 152 from entering the said aperture. The provision
of spring 162 is a safety feature because it makes shaft 160 very
difficult to turn by hand. Only the full weight of the user on the
foot rests can turn shaft 160 when screw 164 is in retracted
position.
In operation, assuming the upper and lower parts of the pogo stick
are latched together, the stick can be placed in operation by an
individual standing on the foot rests and then tilting the stick
toward himself which will cause the unlocking mechanism connected
with the foot rests to dislodge the locking plunger, so that the
two parts of the stick are free to reciprocate. The stick can then
be used in a conventional manner and can be stopped with the two
parts locked in a position near maximum telescopic engagement by
tilting the stick away from the user at an angle of, say, 5.degree.
to 10.degree..
The user of the stick can readily preset the spring bias by
availing of the crank contained in the handgrip and can cause the
spring tension gradually to increase or decrease or to remain
unchanged during the use of the stick by adjustment of the ratchet
drive mechanism.
The slip clutch slips at a certain torque and prevents any damage
to any part of the apparatus should the plate on the screw reach a
limit position during operation of the ratchet assembly in drive
condition.
As mentioned, the stick can be made without automatic adjustment of
the spring, in which case the spring could be adjusted
manually.
Modifications may be made within the scope of the appended
claims.
* * * * *