Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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1 BACKGROUND OF THE INVENTION
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1. 'F'i-el-d of t'he''Inventi'on
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The present invention relates generally to the field
of muscle development, exercise and rehabilitation and more
particularly to a new leg exercise apparatus.
2. ' De'scr'iption of the''Pr'i'or Art
In designing strength or exercise training equipment,
three types of muscle contractions must be considered~ These
three types include isometric or static contractions, concen-
tric or positive contractions, and eccentric or negative con-
tractions.
Isometric contractions are contractions in which the
length of the muscle remains unchanged while the muscle developS
tension. These types of contractions occur when a muscle applies
a force against an immovable o~je~-t. A concentric contraction
occurs when the'muscle'shortens as it develops tension and over-
~ comes the resistance. In an eccentric con-traction, the external
resistance overcomes the active muscle and the muscle lengthens
while developing tensionO
The devices of the prior art take into account, some
or all of these types of muscle con-tractions. The devices
hic~ only take into account some of the foregoîng types of
contractions, do not make maximum use of the exercise. If a
device or apparatus can take into account all three types of
contractions, much more increased development of the muscle will
occur during a specific exercise.
The equipment on the market today which in fact takes
into account all three types of contractions, is ex~remely cumber
some and expensive. As a result, this e~uipment is found only
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1 at institutions, health clubs, rehabilitation centers and the
like. As a result, they do not have wide-spread use by athletes
~hich require a ligh~-weight, inexpensive and portable apparatus
which is suitable for home use and also use at training facili-
ties.
A further drawback of the prior art devices is that
they do not provide for differing velocities of movement during
the exercise. In other words, the exercise is performed at a
continuous rate o~ speed which restricts the ability of the person
doing the e~ercises from achieving maximum benefit from the
exercise. In designing strength training equipment, it is an
important consideration to consider the strengt~ curve which is
defined as the variation in strength that a muscle undergoes
through a range of movement. While different syste~s have
incorporated some aspects of variable resistance in the system,
most systems have not provided sufficient means to correlate
variable resistance with the strength curve.
One such prior art device is illustrated in U.S.
patent number 3,822,599 issued on July 9, 1974 to Brentham.
This device is based on the concentric contractions of muscles
and does not consider all three types of mu~cle contractions as
set out hereinbefore. ~nother device by the same inventor, as
illustrated in U.S. patent 4,066,259 granted on January 3, 1978,
provides for concentric contractions.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention
to at least partially overcome these disadvantages by providing
a novel leg exercîse apparatus which will produce isometric,
concentric and eccentric contractions in a muscle, and which
will allow for differing velocities of exercise movement.
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1 It is a further object of this invention to provide
a novel leg exercise apparatus which is simple in design and
which may be manufactured and sold for home use.
It is a yet further object of the present invention to
provide a light-weight and portable leg exercise apparatus.
A still further object of the present invention is to
provide a novel leg exercise apparatus whieh ineludes variable
resistanee and which can be operated to provide maximum muscle
strengthening ahility in correlation to the strength eurve of the
preseleeted musele.
A still further object of the present invention is to
provide a leg strengthening apparatus which uses no auxiliary
fluid supply souree and is eompletely self-contained and easy
to operate, yet eompletely safe.
~O this end, in one of its aspects, the invention
provides a leg strengthening apparatus which eomprises
an air reservoir;
a valve means adapted to control the flow of air into and
out of said reservoir;
a eylinder in communication with said valve means, said
eylinder having a piston slidably disposed therein;
aetuating means adjustably seeured to said piston.
In another o~ its aspeets, the invention further
provides a leg strengthening apparatus which eomprises an air
reservoir whieh comprises a stand having an air pocket therein,
and an elongated tube in communication with said pocket;
a valve means adapted to control the flow of air into and
out of said reservoir, said valve means comprising a valve, a
handle adapted to operate said valve, and a eonneeting tube eon-
nectlng said valve to a cylinder which is secured to said stand
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1 said valve comprising a housing and a valve seat which is
reversably movable from a position communicating with said cylinder
by said connecting tube to said air reservoir, to a non-com-
municating position;
said cylinder in communication with said valve means and
having a pisto1l and a piston seal slidablv disposed therein, said
piston ex~ending beyond the -top of said cylinder,
an actuating means adjustably secured to said piston, said
actuating means comprising a pair of padded shoulder rests.
Further objects and advantages of the invention will
appear from the ~ollowing description.
BRIEF DESCRIPTION OF THE DRAWINGS
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FIGURE 1 is a top plain view oE thé apparatus o~ the
present invention.
FIGURE 2 is a side elevational view of the apparatus
of the present invention.
FIGURE 3 is an exploded side elevational view of the
air reservoir, the valve means and the cylinder of the present
invention~
FIGURE 4 is an end elevational view of the wheel and
the wheel housing and cylinder cap.
FIGURE 5 is a sectional view of the valve in the
priming position.
FIGURE 6 is a sectional view of the valve in the
operative position.
FIGURE 7 is a side elevational view of the piston rod
of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The apparatus consists essentially of an air reservoir,
a valve means adapted to control the flow of air into and out of
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1 the reservoir, a cylinder in communication with the valve means
and a piston slidably disposed in the cylinder and extending
outwardly from one end of the cylinder, and actuating means
adjustably secured to the pis-ton and adopted to apply
resistance against its movement.
Referring now to figures 1 and 2, the air reservoir
comprises a stand 14 and an elongated tube 30 in communication
therewith. The stand 14 is hollowed out so that air can be
retained therein. The stand 14 also serves as a platform upon
which the operator can stand when using the apparatus and it may
be made of any suitable material.
The tu~e 30 is secured to the stand 14 by fi.rst bracket
32 and it communicates with the interior of the stand 14. Thus,
there is free flow of air between the tube 30 and the stand 14.
The valve means comprises a valve 34, -the operation
of wh~,ch.i`s controlled by handle 36. A second tube 38 is provided
to connect the valve 34 to a cylinder 26.
The cylinder 26 includes a piston as shown in figure 7
which comprises a piston rod 25 and a piston seal 27. The piston
~ is slidably disposed within the cylinder 26 and the piston rod
': 25 extends a~ove t~e top of the cylinder 26 as sh.own in figure 2.
The actuatlng means comprises a pair of shoulder rests
: : 10, which are secured to the piston rod 25 ~y bracket 2Q in any
well known manner. The shoulder rests 10 are generally padded
with paddi.ng 16 on the undersurfa.ce thereof to increase the
comfort of the user when the apparatus is in use~ While the
padding 16 is not necessary, it is generally preferred to ease
the strain on the.shoulders. The undersurface of the shoulder
rests 10 are ~enerally sloped to correspond to the natural slope
of the users shoulders,
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The shoulder rests 10 extend horizontally outwardly
from t~e rod 25 and are secured thereto by an adjustable bracket
20.. The bracket may be an integral part of the shoulder rests
lQ or i`t may ~e a separate component. The height of the
shoulder rests 10 is completely adjustable to accomodate
d~fferent he~g~ts- of operators. Rod 25 may also be adjustable
in height if desired, by any well known means such as being
constructed of a plurality of interlocking telescoping pieces.
As shown .in ~igure 3, the cylinder 26 is mounted on
stand 14 by a pair of mounting plates 50, Sl, the former being
secured to t~e base o~ the cvlinder 26 and the latter being
secured to the top of the stand 14. Bolts 48 extend through the
plake 50 into plate 51 to secure the cylinder 26 to the stand 14.
wheel housing and cylinder cap 40 is provided on
the top of the cylinder 26. This housing 40 houses wheel 42
upon which piston rod 25 travels. The wheel 42 acts as a guide
to ensure proper orientation of the piston rod 25.
: Figure 3 shows an exploded view of the valve means, the
air reservoir and the cylinder~ Reference is also made to figure
4 which. s~ows an end elevat~onal view of.the wheel 42 and the
wheeI housi`ng and c~linder cap 40. Wheel 42 is mounted on
~: axle 44 in wheel ~ousing 40~ The whee.l housing 40 has a seal
46 attac~ed to the undersurface thereof which seals th~ cylinder
26.
Tu~e 30 is mounted onto stand 14 by ~racket 32 which
in this embodiment, comprises a pair o~ toggle arms 52 with a
cam seal (not shown~ inside bracket 32. ~hen placed over
spindle 54, the toggle arms 52 are moved upwardly to the desired
position to secure bracket 32 to spindle 54. Thus, tube 30 i5
retained in open communication with the interior of stand 14.
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1 Referring now to figures 5 and 6, there are shown
sectional views o~ the valve 34 in the priming position ~figure
5) and the operative position (figure 6).
Valve 34 consists of a housing 56 in which is mounted
laterally, a cylindrical seat 58 which is rotatable about the
centre axis by movement of the handle 36 ~not shown~. The seat
58 comprises a first chamber 60 and a second chamber 62 which,
depending upon the rotational position of seat 58,will com-
municate with either the conduit 6~ or the conduit 66. In the
primary position, first chamber 60 communicates with conduit 64
and second chamber 62 communicates with conduit 66. In the
operative position, chamber 60 is in communication with
conduit 66 and chamber 62 is not involved.
The chamber 60 is separated from the chamber 62 by a
vented valve disc mount 68 which has a rubber valve disc 70
secured to one surEace by means of a screw 72 or similar means.
A pressure release and priming intake valve unit 74 is
located in housing 56 and consists of a second rubber valve disc
76 secured by screw 78 in a second ven-ted disc valve mount 80.
An air pressure release plunger 82, mounted in an air pressure
release mount 8~, which is secured to the housing by screw ~6,
communicates with one of the channels in the vented disc valve
mount 80.
An air pressure gauge 29 is mounted on the cylinder 26
as shown in figure 2 and allows the user to quickly ascertain the
amount of air pressure in the cylinder 26 at any given time.
The operation of the apparatus will now be explained in
detail. The operator of the device first adjusts the height of
the shoulder rests 10 such that they contact the shoulders in the
squatting position while the operator is standing on the stand 14.
The handle 36 is then moved which -turns the seat 58
to the priming position. In one embodiment, the seat has an
indicator attached thereto and the indicator is located on the
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1 outslde surface of the housing to inform the operator that the
seat ls in either the priming position or the operating position.
Once the handle 36 is moved to the priming position,
the seat 58 is orientated as shown in figure 5. In this position,
first c~amber 60 is in partial communication with first conduit
64 which communicates with second tube 38 which in turn communic-
ates with cylinder 26. First chamber 60 communicates with second
chamber 62 by the ac-tion of the disc valve 70 which in turn com-
municates with second conduit 66, tube 30 and stand 14 which
serves as a reservoi:r
The operator now proceeds ~o load or charge the apparatus
in the ~ollowing manner. The operator pushes upwardly on the
shoulder rests 10 which causes the piston rod 25 to move upwardly
thus.reducing the volume in the cylinder above the piston seal 27
and below .seal 46. This.causes a positive pressure within the--sys-
tem and urges the second rubber disc valve 7-6 to seal shut.thereby
preventing any air loss through vents 88. As the second rubber
disc valve 76 is forced closed, the air pressure causes disc
valve 70 away from mount 68 thus opening vents 90 and allowing
29 air to move to the storage platform 14 via tube 30.
The shoulder rests 10 are then pulled downwardly by
: the operator which moves the piston rod 25 downwardly into the
cylinder 26. This increases the volume of the cylinder between
seals 27 and 46 creating a negative pressure in the system. The
negative pressure pulls the disc valve 70 towards the mount 68
and is sealed thereto. The second rubber d.isc valve 76 is urged
upwardly due to this negative pressure and air is pulled into the
system through vents 88 into conduit 64, through tube 38 and into
the chamber 26.
The operator then raises the shoulder rests 10 and the
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1 process is repeated thereby increasing the amount of air
stored in the stand 14. By repeating the process several times,
the system is charged to the desired level. The amount of the
pressure of the air in the system determines the amount of
xesistance in the apparatus and thus allows for complete adjust-
ability of this parameter for muscle development.
When the system is charged or loaded to the desired
level, the handle 36 is turned to the operating position which
xotates the seat 58 to the position as shown in figure 6. In
this position, there is an open channel from the stand 14,
through tu~e 30, through'second conduit 66, through'first chamber
60, throug~l first conduit 64, through second tube 38 into the
cylinder 26 where the air pressure can act upon the piston and
the piston seal to provide resistance for the operator.
Since the end of the piston rod 25 in cylinder 26 has
~n air-tight' seal 27 cn its lower end, no air from the system
will traveI to the cylinder 26 below the end of the piston rod.
' As the operator does his exercise ~y pressing upwardly on the
; shoulaer rests 10, he must force the air back through the system
to the stand 14. This is caused by the action of moving the
piston rod 25 by moving the shoulder rests 10. ~he degree of
resistance toj this exercise is determined by the amount of pressure
in the'system which is created by charging the system. When
the operator is fully erect, the air pressure will tend to
force the p~ston rod 25 downwardly in the cyl;nder 26. By
resisting the return of the piston rod 2S, the opera-tor create$
exercise in the downward movement of the shoulder rests 10 as
well as the upward movement thereo~.
When the operator wishes to release some or all of the
pressure in t~e system, he merely presses in plunger 82 which
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1 forces the second rubber disc valve 76 upwardly allowing release
of the pressure through vents 88.
The present device has effectively allowed for all
three types of muscle contractions. If the pressure in the
system is built up to a point where the operabor cannot move the
shoulder rests upwardly because of the air pressure in the
system being exerted in the opposite direction, by forcing up-
wardly on the shoulder rests 10, the operator causes isometric
contractions of his muscles.
Concentric contractions are achieved by maintaining the
pressure in the systems at a level wherein the operator can press
the shoulder rests 10 upwardly but against a substantial force.
In this case, the operator's muscles' contract concentrically.
In the downward stroke of the piston rod caused by the increased
pressure in the system, the operator tries to resist this move-
ment and thus causes eccentric contractions of his muscles.
It is a further advantagé of the system that it is
rather simple in manufacture and thus, of reduced costs. It
is made of light material and thus, the whole apparatus can ~e
29 portable and moved to the appropriate training sites.
The system may be charged to the indi~idual specification
of the operator, thus allowing for variable resi~tance in the
system. The present invention also allows fcr biomechanical
accommodation, that is, it allows for a variation in the resi5tance
in the system in conjunction with the strength curve required
by the particular exercise and by the particular athlete. As the
operator moves ~he shoulder rests 10 upwardly towards the top
of its travel, the amount of storage space for the air in the
system is reduced thus increasing the resistance in the system.
3~ ~y doing so, the resistance in the system varies o~er the range
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1 of the exercise itself which produces improved muscle training
and improved speci~icity of training.
The present invention is easy to operate and provides
an excellent leg exerciser. The operator first adjusts the
handle 36 ~o the priming position and then adjusts the shoulder
rests to the correct height. He then bends his knees and places
his shoulders underneath the shoulder rests. The operator then
stands straight up raising the shoulder rests to the top of their
travel, then pulls the shoulder rests 10 downwardly to the
bottom of their travel. This motion is repeated until the
apparatus is primed to the desired pressure. I~he operator then
turns the handle 36 to the operating position and performs the
desired exercise.
A particular advantage of this apparatus is that it
~llows the operator to warm-up at the same time as priming the
machine. Thus, as the pressure of the air is increasea in the
apparatus~ t~e operator becomes progressively "warmed-up" and is
ready to do his exercises.
The invention may be varied within the spirit and scope
of the present invention. ~ further embocliment of the invention
includes an apparatus which is based on a par-tial vacuum rather
than positive air pressure. This embodiment may be made with
a sin~le rearrangement of the parts of the embodiment shown in
figures 1 to 7.
In the embodimen~ using a partial vacuum, the valve
means is altered and the release valve unit 74, the second rubber
disc valve 76, screw 78 and the plunger 82 and the mount 84 are
removed and the conduit leading directly to the release valve
unit 74 is sealed shut. Connecting tube 30 is also removed as
well as the bracket 32.
The priming factor o~ the second rubber disc valve 76
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is relocated to a mounting in the piston inside the cylinder 26.
The pressure release function is separate and mounted directly
on the storage platform~
In the priming position, when the shoulder rests are
moved upwardly, the disc valve 70 is urged away from its resting
position thus expelling the air directly through conduit 66
where it is expelled to the exterior environment.
As the shoulder rests are forced downwardly, disc valve
70 closes thereby preventing any air from the outside from
entering the system. As the piston moves downwardly, a progres-
sivel~ larger vacuum is created in the chamber above the piston
seal then exists below the seal. The piston seal is constructed
to open and the air pressure contained in the storage base passes
up into the cylinder through a sealed orifice connecting the
cylinde:r to the base. ~s the shoulder rests are raised again,
this causes more air to be expelled from the system.
The piston seal is constructed similar to the second
valve disc 76 such that air will move only upwardly. When the
piston is moved upwardly due to the upward movement of the shoulder
; : 2~ rests, the piston seal seals thus forcing the air out through
~ the valve disc 70. On the downward stroke, the piston seal opens
: thus equalizing the pressure in the system. As the system i.$
: repeated, a larger vacuum is built up.
To initiate the exercise system, the handle.36 is turned.
to the operating position, thus causing an open channel through
conduit 66, channel 60, conduit 64 and tube 38, which allows
.atmospheric air to enter the upper portion of the cylinder
; acting directly on the upper surface of the piston. Because a
partial vacuum has been created in the storage platform connected
to the bottom of the cylinder, this results in a downward force
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1 applied to the piston by the a ~sp~ere. ~o reduce the vacuum,
a simple valve serving a similar function to plunger 82 is
conveniently located on the stand 14. By opening this valve,
atmospheric air enters the stand 14 thus equalizing the air
pressure on the upper surface of the piston.
Although the disclosure describes and illustrates a
preferred embodiment of the invention, it is to be understood
the invention is not restrictive to this particular embodiment.
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