Patent Application
20230110120
Not Applicable
Not Applicable
Not Applicable
Resistance training offers an effective means for developing strength and building muscle tissue. The efficacy of any exercise is governed by the resistance applied to the body. Exercise machines traditionally require the user to move a fixed resistance or weight through a particular range of motion (ROM). The resistance or load applied to the athlete's body will vary depending on the location of the body during the ROM.
While exercise equipment allows the user to select a desired weight or resistance, neither free weights nor standard friction, pneumatic, or hydraulic resistance mechanisms deliver adaptive user-generated resistance throughout the ROM of a given exercise. Anatomical variation and changing loads throughout the workout lead to overdevelopment of some muscle groups and underdevelopment of others. Those who set the equipment at a high resistance or users who make explosive movements may sustain injury at points within the ROM.
As muscles contract to move a limb or limbs, it is the length of those limbs along with the weight or resistance selected that determines the actual force applied to the body. The longer the limb, the greater the moment or torque exerted on that limb. To illustrate this concept, consider a ten pound weight connected to one end of a rod. A person will find it much easier to lift the rod closer to the load than to pick it up at the rod's opposing end. The nature of leverage makes the exercise feel more challenging the farther one lifts from the weight. The load has not changed but the moment is greater when the rod is lifted at its far end. This concept applies to simple exercises such as bicep curls where a weight is held by the hand and moved in an arc toward the body. The elbow acts as a fulcrum and the resistance or perceived weight varies throughout the travel of that exercise, feeling heavier when the arm is outstretched than when it is closest to the body.
In more complex exercises such as a dead lift, the knees, hips, and ankle joints each act as a fulcrum, further changing the leverage or resistance exerted on the individual's muscles throughout the ROM. The load or weight in this case is the weight of the lifter's body in addition to free weights the individual is holding or, alternatively, the resistance applied by a machine. Picking a weight directly off the floor or from an extended starting position may result in injury. As in the example of the bicep curl, the resistance applied to the body at any given point in time will vary depending on where the body is positioned in the ROM for that exercise.
The physical stature of the person exercising also affects the level of resistance throughout the motion. In a squat for instance, the longer the femur, the greater the distance between the load and the fulcrum, and consequently, the more difficult it is to move a given amount of weight. This means that a shorter person has a body that is better adapted for squats and that individual may therefore exercise more efficiently in that particular ROM.
Free weights and existing fitness equipment fail to address the inherent problem of varying torque throughout the ROM and do not account for anatomical variation in individuals performing the selected exercise. Because the resistance varies throughout the routine, the athlete may struggle to maintain a safe form under increased weight and release of that weight may lead to injury in an emergency. Additionally, a great deal of time is often spent adjusting the load as standard weight increments are typically no smaller than five pounds. As a result, athletes are forced to select a predetermined weight at which they are prepared to fail rather than a desired machine speed where the equipment matches exerted force with an instantaneous opposing resistance to maintain a consistent velocity during the ROM.
There is therefore a need in the art for exercise equipment that addresses variation in anatomy, provides consistent speed and instantaneously adaptive user-generated resistance to the exerciser throughout the entire ROM, and permits more granular adjustment of machine speed for more effective exercise.
There is a growing trend in exercise known as isokinetics. This is a strength training method that blends the intense muscular contractions experienced in isometric exercise with the full ROM required in isotonic workouts. True isokinetic machines require each targeted muscle group to work against an adaptive user-generated resistance that maintains a constant velocity throughout the entire path of the exercise (hereinafter “user-generated resistance”). The present invention provides a means for achieving this type of workout through dead lift, squat, bench press, abdominal, and latissimus dorsi (lat) machines among others. A specialized hydraulic system is connected to the user driven element(s) of the machine. This system maintains a constant fluid flow throughout the exercise stroke and facilitates a user-generated resistance that opposes the force applied at the user driven element at any given moment in time.
It is an object of the invention to provide an isokinetic module and method for delivering constant speed or velocity within a piece of exercise equipment while storing no detectable energy within that system. This allows the user to release the machine without fear of injury.
Typical free weight and pneumatic exercise machines require the user to pre-select a weight or resistance based on their perceived maximum ability. The athlete may under or overestimate their physical capacity when they exercise to failure. Sudden movement or inconsistent speed changes within the ROM may result in injury, and some amount of energy remains in the machine where it may cause further injury. This is completely avoided by using the present module and method. The isokinetic control module allows the user to dial in a desired speed while applying as much force as they wish throughout the ROM. The speed at which the user-driven element moves in any given piece of exercise equipment will be determined by the selected speed level; the athlete will not be able to make sudden movements or accelerations that result in injury nor will potential energy be retained in the module regardless of the force applied. In addition, the module and method places the athlete's muscles in a constant state of strain and contraction throughout the entire exercise. Primary and secondary muscle groups are activated, accelerating muscle fatigue and assisting in the break down and subsequent rebuilding of stronger muscle tissue. The athlete may give everything he or she has in every repetition without fear of injury.
The present invention is comprised of a closed loop hydraulic system having a piston within a hydraulic cylinder capable of generating fluid flow and in fluid communication with a device that controls and regulates the velocity of fluid within the system (said device hereinafter referred to as the PCFC unit). In one embodiment, the PCFC unit is comprised of a pressure compensated flow control valve (PCFC valve) with a speed adjustment mechanism, a PCFC valve inlet, a manifold, and a reverse flow check valve.
In another embodiment the reverse flow check valve is removed and the PCFC valve further comprises a check spool or sleeve and a corresponding spring or similar directional flow device (such valve shall hereinafter be referred to as a PCFC-RC valve) that opens to allow unrestricted fluid flow when the flow direction within the PCFC unit reverses. If the application requires the user driven element to return to its home position more quickly, a third embodiment comprising a PCFC unit that includes both a PCFC-RC valve and a reverse flow check valve may be used.
The rate of fluid flow during the exercise stroke within each of these embodiments is modified prior to working out through the speed adjustment mechanism which can be manually or electronically adjusted. As noted above, a reverse flow check valve, PCFC-RC valve, or combination of the two is used to facilitate unrestricted fluid flow during the return stroke, allowing the user driven element to return to its home position more rapidly in preparation for the next repetition.
A piston within the cylinder is attached to the user-driven element of the exercise equipment. In a dead lift machine, for instance, the piston is connected to the lifting arm of the machine. As the athlete pulls in an upward stroke, the piston extends within the hydraulic cylinder which initiates flow of fluid within the closed hydraulic system. Fluid travels into the first end of the PCFC unit. A flow regulating pressure compensating spool within the PCFC unit ensures that the flow remains substantially constant regardless of any fluctuations within the hydraulic system. It should be recognized that the valve industry commonly refers to valves offering “constant” fluid flow; however, the variable nature of these hydraulic systems results in fluid flow that is “measurably inconstant” and physically discernable by the user. For the purposes of this application “substantially constant fluid flow” is defined such that changes of the fluid flow within the present invention are physically undetectable by the individual using the system. With this in mind, the fluid flow and subsequent difficulty level of the workout will remain substantially constant regardless of the force the athlete applies to the lifting arm of the machine. In other words, the arm cannot be lifted any faster than the selected flow rate within the system will allow during the exercise stroke no matter how hard the athlete pulls on it. By creating this substantially constant fluid flow, the machine taxes both primary and secondary muscle groups evenly throughout the ROM of the exercise. Movement of the piston throughout the exercise and return strokes causes fluid to flow into and out of the cylinder, thereby pushing fluid into and out of the PCFC unit during each stroke cycle.
The machine's lifting arm is lowered during the return stroke, forcing the piston back into the cylinder. This process reverses the flow of fluid within the closed hydraulic system. Liquid within the closed hydraulic loop is forced through the second end of the PCFC unit or, in the case of a one port cylinder, movement of the piston may withdraw fluid from the first end of the PCFC unit. The reverse check flow valve in fluid communication with the PCFC valve via a manifold (or alternatively a PCFC-RC as described above) allows fluid to bypass the flow regulating pressure compensating spool within the PCFC valve such that the user-driven arm can return to its home position quickly.
Ideally, the closed loop hydraulic system is comprised of a two port cylinder or alternatively, a one port cylinder having a breather valve or similar component that allows movement of the piston within the cylinder. The system is designed such that there are no pockets of free air within the closed loop. An accumulator may be added to ensure uniform displacement of fluid within the system.
It is a further object of this invention to offer a method and device for monitoring and displaying the force applied by the user over the ROM of the exercise without having to measure the position of the user driven element. Typically, to graph force versus travel, one measures the force and the position of a sensor within a system. Because the fluid flow rate within the system is substantially constant, the need to measure the position of a sensor is eliminated. A pressure transducer may be introduced into the closed loop hydraulic system to determine the force generated by the user. This transducer measures the pressure of the fluid before it enters the PCFC unit and the pressure exerted over the ROM is converted to a signal by a data acquisition device or system (hereinafter DAQ). These signals are sent from the DAQ to a computer. A program within the computer creates a graphical representation of the workout and may calculate any number of statistical outputs based on force over time such as the maximum and average force applied during the workout. The data applying to each lift or cycle of the machine is sent to a display screen, allowing the user to visualize physical performance over a series of repetitions.
As previously mentioned, the dynamic nature of the machine maintains a consistent tension or force on the targeted muscles. Because the fluid velocity within the system remains constant regardless of the force applied, the risk of injury is significantly reduced making this an ideal means for rehabilitation of injured or compromised muscles. The self-contained and modular nature of the isokinetic module and method allows it to replace the standard stacked weights and inconsistent pneumatic and hydraulic resistance mechanisms currently employed on exercise equipment. Ultimately, this provides a more controlled and cost effective means to achieve isometric exercise.
In this patent application, the moveable portion of an exercise machine defining the ROM of a particular movement shall be referred to as a “user driven element,” “arm,” or “lifting arm.” It should be noted that more than one user driven element or lifting arm may exist on any given piece of exercise equipment. Pipe, conduit, and tubing capable of withstanding the pressures within the closed loop hydraulic system contemplated herein shall be referred to as “hydraulic tubing.” While inventor contemplates the use of oil in the closed loop hydraulic system, the term “fluid,” as used in this application, shall mean any incompressible liquid.
Exercise equipment generally has an “exercise stroke” wherein the user driven element 10 is moved in one direction to tax a targeted group of muscles. The equipment also has a “return stroke” wherein the user driven element 10 moves in the opposite direction and either allows the user's muscles to recover or, alternatively, exercises a different group of muscles. It should be recognized that the direction of flow in a given application will depend on how the module is connected to the user driven element.
One object of the present invention is to create a family of exercise machines by mounting an isokinetic flow control mechanism 5 (hereinafter “mechanism”) to the user driven element(s) 10 of the respective equipment. The substantially constant flow of fluid within this mechanism 5 translates to instantaneously adaptive user-generated resistance throughout the specific ROM linked to the user driven element 10. The mechanism 5 prohibits the exerciser from moving the user driven element 10 faster than the selected speed during the exercise stroke, regardless of the force applied.
Another object of the invention is to offer a device and method that provides resistance to the user only when that user is applying force to the machine in which it is connected (“user-generated resistance”). The moment that user relaxes, the machine returns to its home position, gently but rapidly preparing for the next repetition. The immediate release of resistance enhances safety particularly when the user is feeling exhausted by the exercise.
While inventor anticipates the creation of multiple species of exercise equipment incorporating this mechanism 5, it should be recognized that one may also upgrade friction based or standard hydraulic resistance units in existing machines with the mechanism 5 described herein. Replacement of these standard resistance methods will result in a safer and more efficient means of exercising the selected muscle group(s) by offering a constant speed and subsequent instantaneous and adaptive user-generated resistance rather than a mechanism that can be overcome with additional force.
In one embodiment, illustrated in
The heavy arrows in
In the embodiment shown in
The heavy arrows in
During the return stroke of this embodiment, the movement of the hydraulic piston unit 25 within the cylinder 20, drives fluid 35 below the piston 55 out of the lower port 50. Fluid 35 subsequently flows in a reverse path to that described in the exercise stroke. Pressure within the system drives fluid 35 within the manifold 65 into the reverse flow check valve 70. This reverse flow check valve 70 uses a spring-backed piston that opens when fluid 35 enters the bottom of said valve 70; this allows fluid 35 to flow into the upper port 45 of cylinder 20 above the piston 55. By bypassing the PCFC valve 75, the user driven element 10 can be quickly returned to its home position.
One should note that the top rod of the piston 60 displaces fluid; the position of the top rod within the cylinder consequently displaces fluid at a different rate above the piston than it displaces below it. While there is a negligible amount of air in the system, all fluid traps some quantity of air by its nature. As the piston extends and retracts, the minute quantity of air within the system compresses or expands respectively. This may lead to an undesired suction within the system, undermining the function of the machine.
In a return stroke for example, the volume of fluid beneath the piston 55 will increase at a faster rate than the volume of fluid 35 decreases above that piston 55. This disparity in the rate of volumetric changes throughout the stroke creates suction. An optional tee 80 and accumulator 85 may be added to the closed loop hydraulic system 15 to compensate for this disparity as shown in
The accumulator 85 is comprised of an accumulator piston 90 supported by an inert pressurized gas 95 such as nitrogen. This inert pressurized gas 95 exerts a constant force on the accumulator piston 90 that inversely increases as the volume beneath the accumulator piston 90 decreases. An optional charge port 100 may be mounted beneath the accumulator 85 to allow for periodic recharging of the inert pressurized gas 95 as needed.
A given quantity of fluid 35 is stored above the accumulator piston 90 at any instant in time. As the volume of fluid 35 below the piston 55 increases, the accumulator piston 90 moves upward, pushing the stored fluid 35 through the tee 80 and down toward the lower port 50 of the hydraulic cylinder 20. See
While
The difference between the first embodiment and the invention illustrated in
Referring again to
Referring now to
Referring now to
In each embodiment, the user selects a desired flow rate corresponding to the desired difficulty level of the exercise prior to starting their workout. The bold arrows in
Once the flow rate has been selected and the athlete applies force to the user driven element 10 during the exercise stroke, fluid 35 flows in at the inlet 72 of the PCFC valve 75. Referring to
In embodiments where a PCFC-RC valve is used, the valve further includes a check spool and sleeve and corresponding spring that opens only in one direction of fluid flow to bypass the restriction mechanism 120. The opening of the check spool or sleeve allows unrestricted fluid flow within the system as a constant flow is not required in this stroke. See
The pressure within the PCFC valve inlet 72 may be read by an optional pressure transducer 140 in fluid communication with said inlet 72. The pressure transducer 140 may alternatively be positioned prior to the manifold 65 near the PCFC valve exit or within the cylinder 20. See
As previously noted, the present invention 5 may be incorporated or retrofitted into a variety of exercise machines.
The top rod 60 of the hydraulic piston unit 25 is similarly affixed to the user driven element 10 of the abdominal machine shown in
The above mentioned examples have been included to illustrate the adaptable nature of the isokinetic flow control module 5. The present invention may be used within a variety of exercise equipment; subsequently, the position of said module 5 will depend on the location of the user driven element 10 on any given piece of equipment. Similarly, the direction flow within the closed loop hydraulic system will also depend on the placement and connection of individual components within that system.
While the above description contains many specifics, these should be considered exemplifications of one or more embodiments rather than limitations on the scope of the invention. As previously discussed, many variations are possible and the scope of the invention should not be restricted by the examples illustrated herein.
This application claims benefit of priority from U.S. Provisional Patent Application No. 63/254,235 of Mark Small, filed Oct. 11, 2021, entitled HYSTERETIC ISOKINETIC CONTROL MODULE & METHOD FOR STRENGTH TRAINING WITH GRAPHICAL FORCE DISPLAY, the entirety of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63254236 | Oct 2021 | US |
