U.S. patent application number 11/395801 was filed with the patent office on 2007-10-04 for reciprocable load resisting device.
Invention is credited to Michael Roydon Puzey.
Application Number | 20070232467 11/395801 |
Document ID | / |
Family ID | 38559942 |
Filed Date | 2007-10-04 |
United States Patent
Application |
20070232467 |
Kind Code |
A1 |
Puzey; Michael Roydon |
October 4, 2007 |
Reciprocable load resisting device
Abstract
A load resisting device for use in an exercise machine which
includes a cylinder, a piston which is movable in a first direction
inside the cylinder against a force generated by air pressure in
the cylinder, and an O-ring seal, mounted to the piston, which
provides a seal between the piston and the cylinder, when the
piston is moved in a first direction, and which allows air to
bypass the O-ring when the piston is moved in a second direction
which is opposite to the first direction.
Inventors: |
Puzey; Michael Roydon;
(Randburg, ZA) |
Correspondence
Address: |
KEUSEY, TUTUNJIAN & BITETTO, P.C.
20 CROSSWAYS PARK NORTH
SUITE 210
WOODBURY
NY
11797
US
|
Family ID: |
38559942 |
Appl. No.: |
11/395801 |
Filed: |
March 31, 2006 |
Current U.S.
Class: |
482/112 |
Current CPC
Class: |
A63B 21/4015 20151001;
A63B 21/0087 20130101 |
Class at
Publication: |
482/112 |
International
Class: |
A63B 21/008 20060101
A63B021/008 |
Claims
1. A reciprocable load-resisting device which includes a cylinder
with an inner closed end and an outer, open end, a piston which is
reciprocably located inside the cylinder thereby defining a volume
of variable size inside the cylinder between the inner closed end
of the cylinder and a first side of the piston, a rod which is
fixed to the piston and which extends from the cylinder through the
outer, open end, a first mounting formation on the cylinder, a
second mounting formation on the rod, a one-way valve which is
associated with the piston and which opens to allow fluid to flow
into the volume when the piston is withdrawn from the cylinder and
which closes when the piston is moved into the cylinder so that the
piston causes fluid inside the volume to be pressurised, an outlet
from the volume through which fluid can flow when the volume is
pressurised, and a control mechanism which is adjustable to control
the rate at which fluid can flow from the volume.
2. A load-resisting device according to claim 1 wherein the outlet
returns fluid which flows from the volume to the cylinder on a
second side of the piston.
3. A load-resisting device according to claim 1 which includes a
cap which is fixed to the outer, open end of the cylinder and which
includes an opening through which the piston rod extends.
4. A load-resisting device according to claim 1 which includes a
bypass conduit which extends from the volume to a portion of the
cylinder between the second side of the piston and wherein the
outer end of the cylinder and the control mechanism is engaged with
the bypass conduit.
5. A load-resisting device according to claim 1 wherein the control
mechanism is mounted to the piston so that fluid can flow through
the piston, or bypass the piston, when it flows from the volume to
the cylinder between the outer, open end and the second side of the
piston.
6. A load-resisting device according to claim 5 wherein the control
mechanism may be adjustable to allow fluid to flow, inside the
cylinder, from the first side of the piston to the second side.
7. A load-resisting device according to claim 1 wherein the one-way
valve is formed by an O-ring which is mounted to the piston and
which is moved from a sealing position, when the piston is moved
into the cylinder, to a non-sealing position, when the piston is
withdrawn from the cylinder.
8. A load-resisting device for use in an exercise machine which
includes a cylinder, a piston which is movable in a first direction
inside the cylinder against a force generated by air pressure in
the cylinder, and an O-ring seal, mounted to the piston, which
provides a seal between the piston and the cylinder, when the
piston is moved in a first direction, and which allows air to
bypass the O-ring when the piston is moved in a second direction
which is opposite to the first direction.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to a load-resisting device which is
suitable for use in an exercise machine such as a rowing machine, a
lifting or curl machine or any similar apparatus which requires
muscular energy for activation.
[0002] In an exercise machine of the aforementioned kind it is
desirable to provide a load-resisting device which offers
resistance to effort which is exerted by muscular force, which is
of inexpensive construction and which is easily adjustable, in
respect of its load-resisting characteristics, to suit different
users.
SUMMARY OF INVENTION
[0003] The invention provides a reciprocable load-resisting device
which includes a cylinder with an inner closed end and an outer,
open end, a piston which is reciprocably located inside the
cylinder thereby defining a volume of variable size inside the
cylinder between the inner closed end of the cylinder and a first
side of the piston, a rod which is fixed to the piston and which
extends from the cylinder through the outer, open end, a first
mounting formation on the cylinder, a second mounting formation on
the rod, a one-way valve which is associated with the piston and
which opens to allow fluid to flow into the volume when the piston
is withdrawn from the cylinder and which closes when the piston is
moved into the cylinder so that the piston causes fluid inside the
volume to be pressurised, an outlet from the volume through which
fluid can flow when the volume is pressurised, and a control
mechanism which is adjustable to control the rate at which fluid
can flow from the volume.
[0004] Although the load-resisting device can be used with any
suitable compressible fluid it preferably is used with air.
[0005] Preferably the outlet returns fluid which flows from the
volume to the cylinder on a second side of the piston.
[0006] A cap may be fixed to the outer, open end of the cylinder
and include an opening through which the piston rod extends.
[0007] In one form of the invention the device includes a bypass
conduit which extends from the volume to a portion of the cylinder
between the second side of the piston and the outer end of the
cylinder and the control mechanism is engaged with the bypass
conduit.
[0008] In a second form of the invention the control mechanism is
mounted to the piston so that fluid can flow through the piston, or
bypass the piston, when it flows from the volume to the cylinder
between the outer, open end and the second side of the piston. In
this form of the invention the control mechanism may be adjustable
to allow fluid to flow, inside the cylinder, from the first side of
the piston to the second side.
[0009] The one-way valve may be of any appropriate kind. In one
form of the invention the valve is formed by an O-ring which is
mounted to the piston and which is moved from a sealing position,
when the piston is moved into the cylinder, to a non-sealing
position, when the piston is withdrawn from the cylinder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention is further described by way of examples with
reference to the accompanying drawings in which:
[0011] FIG. 1 is a perspective view of a load-resisting device
according to a first form of the invention in an exploded
configuration,
[0012] FIG. 2 is an enlarged view of some of the components shown
in FIG. 1, and
[0013] FIGS. 3 and 4 correspond respectively to FIGS. 1 and 2 of a
load-resisting device according to a second form of the
invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0014] FIGS. 1 and 2 of the accompanying drawings illustrate a
load-resisting device 10 according to a first form of the invention
which includes a cylinder 12, a piston 14 and a piston rod 16.
[0015] The cylinder includes a cylindrical tube 18 with inner and
outer ends 20 and 22 respectively. The end 20 is closed by means of
a cap 24 which includes a clevis 26 by means of which the cylinder
can be anchored, in pivotal fashion, to suitable supporting
structure in an exercise machine, not shown.
[0016] A cap 28 is used to close the outer end 22 of the cylinder.
The cap has an opening 30 through which the rod 16 passes. The
opening 30 also acts as a bush for the rod. A fixing member 32,
which carries a clevis formation, is fixed to an outer end of the
rod 16 and serves to anchor the rod to a movable component, not
shown, of an appropriate exercise machine, not shown. In use of the
exercise machine force is applied directly or indirectly to the rod
by a person using the machine. The exercise machine may be a rowing
machine, a curl-type machine or the like, typically in which
reciprocating movement takes place against a resistance force of
adjustable magnitude.
[0017] The piston 14 includes a socket 34 and an enlarged collar
36. The collar has a projecting portion 38 which is formed with a
flat surface 40. A flexible O-ring 42 is positioned in a groove 44
formed in the portion 38. The groove does not extend over the flat
surface 40 and the O-ring is positioned so that it abuts an inner
side 46 of the collar surrounding the portion 38.
[0018] The cylinder has an outlet opening 50 and an inlet opening
52 formed through its wall near the inner end 20 and the outer end
22 respectively. A bypass conduit 54 is connected to the outlet 50
and, via a control mechanism 56, to the inlet 52.
[0019] The control mechanism 56 includes a housing 60 with an
internal passage 62 in which is located a ball 64. The ball rests
on a seat 66 to close the passage and is biased into engagement
with the seat by means of a spring 68. The force which is exerted
by the spring on the ball can be adjusted by rotating a knob 70
which is threadedly engaged with a threaded column 72 which
projects from the housing and which houses the spring 68.
[0020] The piston, when located inside the cylinder, defines a
closed volume of variable size inside the cylinder between the
inner end 20 and a first side 80 of the piston. The outlet 50 is in
communication with this volume. A second volume is defined between
a second side 82 of the piston and the cap 28. The inlet 52 is in
communication with this volume. The cap 28 has a number of bleed
passages 84 which allow air to flow into and out of the second
volume.
[0021] In use of the device the piston is reciprocated to and fro
by a user in a manner which depends on the nature of the exercise
machine with which the device is used. The O-ring seal provides a
one-way valve function as follows. When the rod is moved
telescopically into the cylinder the O-ring 42 is pushed against
the side 46 of the piston to a sealing position at which the O-ring
forms an air seal. The air inside a first volume in the cylinder,
ie. on the first side 80 of the piston, is compressed and attempts
to flow through the outlet 50. The free escape of air through the
outlet is constricted by the control mechanism 56. The rate at
which air can escape from the first volume is determined by the
bias force which is exerted by the spring 68 on the ball 64. This
force can be adjusted with ease merely by rotating the knob 70 in
one direction or the other.
[0022] The air which flows through the control mechanism 56 is
returned to the second volume inside the cylinder defined between
the second side 82 of the piston and the cap 28. The air is
returned to the cylinder, as opposed to being allowed directly to
atmosphere, for the air flowing from the first volume is under
pressure and, when venting directly to atmosphere, can be fairly
noisy. By returning the air to the cylinder the noise level is
reduced.
[0023] When the rod is retracted from the cylinder, inside the
cylinder, from the second side 82 of the piston to the first side
80, the O-ring 42 moves slightly away from the side 46, because of
a slight frictional drag against an inner wall of the cylinder and,
due to the flat surface 40 on the portion 38, the O-ring takes up a
non-sealing position in which a passage is created on the piston
through which air can flow. Thus, on a return stroke little of any
resistance is offered to the user.
[0024] Pressure equalisation inside the cylinder can take place, as
necessary, by virtue of the bleed passages 84 which allow air to
flow into or out of the cylinder, on the second side of the
piston.
[0025] The cylinder 12 preferably has a fairly large diameter, for
example of the order of 100 mm, so that although the pressure which
is generated inside the first volume is not unduly high a fairly
significantly force is nonetheless generated which acts in a
load-resisting manner to restrain movement of the rod 16, in a
yielding manner, into the cylinder. The load-resisting force can,
as has been noted, be adjusted readily merely by rotating the knob
70.
[0026] FIGS. 3 and 4 illustrate a load-resisting device which is
designated 10A. Where applicable components in the device 10A which
are the same as components in the device 10 bear similar references
numerals.
[0027] A principal difference between the device 10A, compared to
the device 10, is that the bypass conduit 54 and the control
mechanism 56 are replaced by a control mechanism 90.
[0028] A piston 14A has a circular serrated formation 92 which is
rotatably mounted to a body portion 94 of the piston. A spring 68
bears against a ball 64 which is positioned to engage with a seat
66 at an end of a passage 62 which extends from one side of the
piston to the other (shown in dotted outline in FIG. 4). A cap 28A
has serrated formations 96 which are complementary to the
formations 92. A piston rod 16 has a threaded end 16A which passes
through an opening 30 in the cap and which is engageable with a
threaded socket 98 in the piston. The cap has a circumferential
groove 100 on a projection 102 which extends into an outer end 22
of the cylinder 12. A circlip 104, which is engaged with opposing
slots 106 in the cylinder, is also engageable with opposing
portions of the groove 102 when the cap is mated to the
cylinder.
[0029] A leading end of the rod 16 urges the spring 68 to bear
against the ball 64 which acts to prevent a free flow of air from
one side of the piston to an opposing side, when the piston is
urged deeper into the cylinder. When the piston is withdrawn from
the cylinder an O-ring 42 is moved on the piston and creates a
passage through which air can bypass the piston in a manner which
is similar to what has been described in connection with the device
10 of FIGS. 1 and 2.
[0030] In order to adjust the load-resisting force, which is
offered by the device 10A, a user withdraws the piston 14A to the
maximum extent so that the formations 92 mate with the formations
96 on the cap. The piston is restrained, if necessary, against
rotation, and the cap is rotated in one direction or the other,
according to requirement. An external surface of the cap has
knurled formations 110 to facilitate this rotation. As the cap is
rotated the piston is rotated as well and the piston rod is screwed
deeper into the piston, or to some extent out of the piston,
depending on the rotation direction. The degree of compression of
the spring 68 is thereby adjusted and, in this way, the biasing
force which is exerted on the ball 64 is varied.
[0031] The circlip is designed so that it holds the cap captive to
the cylinder yet allows the cap to rotate relatively to the
cylinder to enable the load-resisting force, generated by the
device 10A, to be varied according to requirement.
[0032] The device of the invention can be used with any appropriate
exercise machine in which a reciprocating movement is produced e.g.
a rowing machine, a lifting or curl-machine, or the like. Generally
the formation 26 would be fixed to supporting structure, and the
formation 32 would be connected directly or indirectly to an
actuator operable by a user.
* * * * *