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Publication numberUS20070259756 A1
Publication typeApplication
Application numberUS 11/799,502
Publication dateNov 8, 2007
Filing dateMay 2, 2007
Priority dateMay 5, 2006
Publication number11799502, 799502, US 2007/0259756 A1, US 2007/259756 A1, US 20070259756 A1, US 20070259756A1, US 2007259756 A1, US 2007259756A1, US-A1-20070259756, US-A1-2007259756, US2007/0259756A1, US2007/259756A1, US20070259756 A1, US20070259756A1, US2007259756 A1, US2007259756A1
InventorsWilliam E. Kuykendall
Original AssigneeKuykendall William E
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method and apparatus for adjusting resistance to exercise
US 20070259756 A1
A potentially infinitely variable resistance to exercise that can be incorporated into most types of exercise equipment is achieved by driving an electrical generator with the physical exertion of the user to power a sufficiently large electrical load. Physical resistance to exercise is controlled by adjusting the output of the generator.
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1. A system that utilizes the kinetic energy of exercise to generate electricity to power external electrical devices, wherein such system comprises (1) at least one variable resistance exercise machine configured to convert the user's kinetic energy input into an electrical generator input; (2) an electrical generator; (3) a rectifier; and (4) current limiting means.
2. The system of claim 1 including a direct current-to-alternating current converter, into which the electrical direct current output of such system is fed for conversion into alternating current.
3. The system of claim 1 including electrical current storage means.
4. The system of claim 1 including a direct current-to-alternating current converter and an alternating current transformer, wherein such transformer is configured to feed the output alternating current into one or more local power grids.
5. The system of claim 1 including a plurality of exercise machines, current converters, and transformers, wherein the electrical current output of such plurality of machines is aggregated for a common source feed into an electrical power grid.
6. A method for the generation of electrical energy, whereby such method comprises capturing the kinetic energy generated by a user of a resistance exercise machine, converting such kinetic energy into electrical energy via an electrical generator, and controlling the electrical generator output with a rectifier and current limiting means.
7. The method of claim 6 further including converting the electrical current output from direct current into alternating current.
8. The method of claim 6 further including storing the electrical current output via energy storage means.

This is the complete application claiming the benefit of co-pending Provisional Patent Application No. 60/798,216 filed May 5, 2006.


The present invention relates to exercise equipment and more particularly, to resistance to exercise movement. More specifically, the present invention relates to a system and a method for harnessing the exertions of persons who are utilizing exercise equipment as a means to generate energy that can be further utilized as a power source for other energy-dependent systems. The present invention particularly encompasses a system and method of converting an individual's movements and exertions against resistance into electrical energy that can either be utilized directly to power other electrical components, or be stored for subsequent utilization by such components.


Variable resistance mechanisms are well known and commonly used in the exercise equipment industry. The simplest apparatus typically employ gravity as the resistive force. The motion imparted to such apparatus causes interchangeable weights of differing masses to be raised vertically against the pull of gravity. The person who uses such an apparatus will add or subtract different masses and will exert more of less force against a gravitational force. More complex apparatus may utilize one or more polymer elastic bands or springs, and the exerciser will exert a force to expand or compress those springs. With apparatuses that are designed for continuous use in an aerobic exercise environment, resistance mechanisms may incorporate frictional components such as, for example, stationary bicycles that include flywheels and variable frictional braking mechanisms against the flywheels, and treadmills that incorporate similar frictional resistance elements. Still other resistance mechanisms incorporate magnetic or electrical resistance forces.

Exercise machines vary in complexity, theory of operation and resistance methods used. A common characteristic of the resistive components most commonly employed in modern exercise equipment is that the energy imparted to the machine through the motion of exercise is wasted in the form of heat that must be dissipated to prevent damage to the device.

Examples of variable resistance mechanisms include the friction device that is adjusted by spring tension described in U.S. Pat. No. 6,149,559 issued to Mackey. An alternate mechanism uses the electrical drag produced by one or more transducers as described in U.S. Pat. No. 6,165,110 issued to Gajda. A third uses rotating magnets to produce resistance that varies automatically in response to the energy imparted by exercise, as described in U.S. Pat. No. 7,011,067 issued to Kolda, et al. None of these devices or apparatuses includes any system or mechanism to capture the energy that is lost to the environment.


The object of the present invention is therefore to provide a system and method to convert the motion of exercise into electrical energy that may be reused to power other devices or stored for later use.

Another object of the present invention is to describe the minimum configuration of components that are required to capture and utilize the energy that is generated when an individual exerts a force against resistance in an exercise environment.

Still another object of the present invention is to incorporate existing electricity-generating devices into exercise methods and apparatuses in order to convert kinetic energy into usable electricity. This object is accomplished via the incorporation of circuitry into the method and apparatus of the invention such that the energy output may be converted into direct current for storage in batteries and similar devices, or alternating current at a sufficient voltage to supplement standard electrical distribution systems such as those connected to public electrical utilities.

A further object of the present invention is to describe a system whereby the degree of resistance to exercise may be varied by circuitry that adjusts the electrical output, such that the output is fed into a load provided by the storage or distribution system to which it is connected.

An additional object of the present invention is to describe alternate control circuit designs that can provide manual, automatic and programmable adjustments to resistance, as required.


FIG. 1 is a diagram giving a functional overview of a preferred embodiment that depicts both the apparatus and method of the present invention.


FIG. 1 comprises a general schematic drawing that depicts a system and method in which variable resistance to exercise generates energy that is recovered and made available for reuse or storage. This system and method may be incorporated into any type of exercise equipment such that the energy imparted into such equipment is transformed into usable electricity.

Initially, the user supplies kinetic energy 1 via any common form of exercise. Kinetic energy is generally supplied in an exercise environment for example, through traditional raising and lowering of weights, via movement of flywheels on stationary bicycles or treadmills, or movement of other elements in an aerobic exercise regime. In the present invention, the traditional resistance sources are supplanted by devices that move electromagnetic field coils, which are otherwise powered via any number of mechanisms that are well-known to practitioners in the art of such systems, in one or more electrical generators 2. Such movement of the powered electromagnetic field coils induced electrical current to flow through the generators' output windings to rectifier 3.

Persons skilled in the art will understand that rectifier 3 is incorporated into the system and method of the present invention in order to prevent generators 2 from acting as a motor in an otherwise idle machine. Rectifier 3 also facilitates the conversion of alternating current to direct current if an alternating current generator is used. The generators' output is determined by the speed of the motion imparted by the user and the electromagnetic field strength of the generators' exciter field coils. The field strength is directly proportional to the current that the system allows to flow through the field coils, which current is controlled by the current limiting device 4.

Initial field current may be supplied from any one of a number of well-known devices. In the preferred embodiment shown in FIG. 1, the initial field current is supplied by batteries of other storage media 5, or by the direct current to alternating current conversion device 6. Output current may likewise flow to storage media 5 or conversion device 6. Also as shown in the preferred embodiment, conversion device 6 can be configured to generate an alternating current output to an alternating current transformer device 7. The transformer 7 is also where voltage can be matched with the local power grid and connected to all of the electrical loads attached to the local power grid.

Increasing the current flow to the excitation field of generator 2 will cause its output voltage to rise to (but not above) the voltage supplied by the storage device 5 or conversion device 6. Additional exciter current causes generator 2 output to be consumed by loads on the grid 8 or stored in the batteries 5. The generated electricity thus consumed is produced by the user's physical exertion, and is felt by the user as resistance to his effort.

It will be apparent to those skilled in the various arts that the foregoing system can be adapted to any configuration or mode of exercise equipment, including either traditional resistance or strength training exercise machines, and other exercise machines that are designed to give the user an aerobic exercise experience. Examples of the latter include treadmills, stationary bicycles, stair-climbing replicators, and elliptical exercise trainers. In large health club facilities it is not unusual for large numbers of these machines to be located in a large, central exercise room. The system of the present invention is readily adaptable so that the multiplicity of these machines can be linked into the system in a parallel configuration to produce a significant amount of reusable electrical power.

The foregoing specification describes a system and method that is configured for one specific use, namely, conversion of kinetic energy expenditures from resistance exercise machines into usable electrical energy. The present invention may also be adapted to capture and reuse energy in other situations in which kinetic energy expenditures are otherwise lost into the general environment.

This concludes the description of a preferred embodiment of the invention. This description has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. It is not intended that the scope of the invention will be limited by the foregoing description.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7862476 *Dec 22, 2006Jan 4, 2011Scott B. RadowExercise device
US7976434 *Dec 21, 2010Jul 12, 2011Scott B. RadowExercise device
US8939871 *Feb 21, 2012Jan 27, 2015Bion, Inc.Acceleration mechanism for exercise equipment
US20090247366 *Mar 20, 2009Oct 1, 2009Frumer John DMethod and apparatus for configuring fitness equipment
US20120217758 *Feb 21, 2012Aug 30, 2012Bion Inc.Acceleration mechanism for exercise equipment
EP2106826A1 *Mar 25, 2009Oct 7, 2009Schwörer Haus KGAssembly with a training device for creating electrical energy
EP2495868A1 *Aug 19, 2011Sep 5, 2012Sports Art Industrial Co., Ltd.Electric energy collecting mechanism for exercise apparatuses
WO2010012055A1 *Sep 17, 2008Feb 4, 2010Da Silva Hercules FerreiraCycle ergometer device for recharging electronic devices and similars
U.S. Classification482/2, 482/1
International ClassificationA63B15/02, A63B71/00
Cooperative ClassificationA63B2021/0055, A63B21/0053
European ClassificationA63B21/005C