Title:
Programmable exercise machine
Kind Code:
A1


Abstract:
An exercise machine has automatic and programmable resistance selection apparatus with vertically aligned weights that are selectable by rotably engaging a lift pin to select each weight stack. The exercise machine further includes a control panel from which the number of weights to be lifted can be ordered by the user. Alternatively the number of weights being lifted may be programmed from a remote location.



Inventors:
Germanton, Kyle M. (Kinnelon, NJ, US)
Teich, Rudor (West Orange, NJ, US)
Application Number:
09/864511
Publication Date:
02/28/2002
Filing Date:
05/24/2001
Assignee:
GERMANTON KYLE M.
TEICH RUDOR
Primary Class:
Other Classes:
482/99
International Classes:
A63B21/062; (IPC1-7): A63B15/02
View Patent Images:
Related US Applications:



Primary Examiner:
RICHMAN, GLENN E
Attorney, Agent or Firm:
GOTTLIEB RACKMAN & REISMAN PC (NEW YORK, NY, US)
Claims:

We claim:



1. An exercise machine comprising: a substantially vertical guide rod; a set of weights arranged in a vertically stacked relationship and movable along said guide rod; a motor-driven selector having a plurality of positions, said selector being arranged and constructed to engage only one of said weights in each position; a motor coupled to said selector, said motor being arranged to selectively shift said selector between said positions thereby selecting said number of weights, while at the same time not being mounted to be carried by the weights; and a lifting member having a distal and a proximal end, said distal end being coupled to said weights to lift a number of said weights as determined by said selector when a force is applied to said proximal end.

2. The machine of claim 1 wherein said weights are aligned to define a passageway and said selector is disposed in said passageway.

3. The machine of claim 2 wherein each said weight has a coupling element extending into said passageway and said selector is adapted to selectively engage said coupling element.

4. The machine of claim 3 wherein the coupling elements are offset for each weight, with each weight being uniquely associated with coupling elements having predetermined angles.

5. The machine of claim 4 further comprising a control unit in communication with the motor to transmit a selection signal to the motor to shift said selector to select the number of weights.

6. The exercise machine of claim 1 wherein the selector comprises a sleeve placed so as to ride on said guide rod; an array of lifting pins placed on said sleeve to engage said coupling element; and a lifting plate coupled to the distal end of the elongated member and having an opening through which said sleeve is secured.

7. The exercise machine of claim 1 wherein the weights do not put a load on the motor as the weights are selected.

8. The exercise machine of claim 7 wherein the motor is a stepper motor.

9. An exercise machine comprising: a plurality of weights, said weights being stacked in a vertical arrangement and defining a cavity extending through said weights, each weight having a coupling member extending into said cavity, said coupling members being angularly offset from each other, said weights being movable vertically along a vertical axis; a motor-driven selector, disposed in said cavity and having a plurality of angular positions, said selector engaging only one of said weights in each said angular position; an elongated member having a proximal end adapted to be held by a user and a distal end coupled to said weights, wherein when the user applies a force on said elongated member, a number of said weights are moved vertically, said number being determined by the position of said selector; an actuator coupled to said selector, said actuator being adapted to move said selector to one of said angular positions in response to commands, said actuator including an electric motor adapted to rotate said selector to one of said positions in response to said commands, said electric motor being mounted as to not be carried by the weights.

10. The exercise machine of claim 9 further comprising a controller in communication with the actuator to retain said commands and upon request transfer said commands to the actuator.

11. The exercise machine of claim 10 wherein said controller has a keypad interface to receive said commands from said user.

12. The exercise machine of claim 11 wherein the controller has a network interface to receive the commands from an external computing system.

13. The exercise machine of claim 12 wherein the commands detail an exercise regimen.

14. An exercise machine comprising: a substantially vertical guide rod; a first set of weights arranged in a stacked relationship and movable along said guide rod; a first motor-driven selector having a first plurality of positions, said first selector being arranged and constructed to engage only one weight of said first set of weights in each position; a second set of weights arranged in a stacked relationship and movable parallel to said guide rod; a second motor-driven selector having a second plurality of positions, said secondary selector being arranged and constructed to engage only one of said secondary weights in each position of said second plurality of positions; an elongated member having a distal and a proximal end, said distal end being coupled to said weights to lift a first number of said first weights and a second number of said second weights as determined by said first and second selectors when a force is applied to said proximal end; a first stepper motor coupled to said first selector, said first motor being arranged to selectively shift said first selector between said positions thereby selecting said first number, said first motor mounted as to not be carried by said first set of weights; and a second stepper motor coupled to said second selector, said second motor being arranged to selectively shift said second selector between said positions thereby selecting said second number, said second motor mounted as to not be carried by said secondary weights.

15. The machine of claim 14 wherein said first set of weights are aligned to define a first passageway and said second set of weights is nested in said first passageway.

16. The machine of claim 14 wherein said first and second sets of weights each define a first and second passageway, respectively, and wherein said fist selector is disposed in said first passageway and said second selector is disposed in said second passageway.

17. The machine of claim 16 wherein each said weights weight has a tab extending into one of said passageways and each said selector is adapted to selectively engage said tab.

18. The machine of claim 17 wherein the tabs of each set are angularly offset with each weight of each set being associated with a corresponding angular tab position.

19. The machine of claim 18 further comprising a control unit in communication with said motors to transmit a selection signals to each said motor to select said first and second numbers.

20. The exercise machine of claim 14 further comprising a lifting plate coupled to the distal end of the elongated member and a coupling member connecting said plate to said selectors.

21. The exercise machine of claim 14 wherein the primary and secondary selectors comprise: a sleeve placed riding on said vertical guide rail and secured in an opening through; and an array of lifting pins placed on said sleeve to selectively engage said coupling element.

22. The exercise machine of claim 14 wherein weights do not put a load on the stepper motors as the weights are selected.

23. An exercise machine comprising: a substantially vertical guide rod; a set of weights arranged in a vertical stacked relationship and movable along said guide rod; a selector having a plurality of positions constructed to engage only one of said weights in each position; a lifting member having a distal end and a proximal end, said distal end being coupled to said weights to lift a number of said weights as determined by said selector when a force is applied to said proximal end; and a control panel for controlling the selector, said control panel being remote from the rest of the machine.

24. The machine of claim 23 wherein the control panel is connected to the rest of the machine by a cable.

25. The machine of claim 23 wherein the control panel is connected to the rest of the machine by an RF link.

Description:

[0001] This application claims the benefit of U.S. Provisional patent application Ser. No. 60/213839 filed Jun. 23, 2000, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to an exercise machine that can be adjusted easily for various resistance levels. More particularly, this invention relates to remotely adjustable or programmable resistance exercise machines.

[0004] 2. Description of Related Art

[0005] Physical exercise for strength training or bodybuilding consists of a sequence of movements that begins at a rest position, provides a stress on a particular muscle or group of muscles for a period of time and then ends at the rest position.

[0006] There are at least three types of machine-based exercises:

[0007] 1. Isokinetic—The machine is programmed to pace the cycle at a constant speed. If the user moves faster, he or she encounters a higher resistance. If the user moves slower, he or she encounters less resistance. This type of exercise is currently not favored for muscle build-up.

[0008] 2. Isometric—The user exerts a force with no movement (e.g. against a wall). This type of exercise is used in physical therapy where damage to the ligaments prohibits large movements. It is not applicable for general muscle building.

[0009] 3. Isocentric—The machine provides a constant force or torque as a resistance. This is currently the most desirable type of exercise for muscle building.

[0010] Various methods of generating constant resistance for machines that can be used to perform isocentric exercises have been suggested in the art. These include machines relying on magnetic clutch resistance, direct DC motor resistance, hydraulic and pneumatic resistance (both passive resistance and work against active pressure sources), springs, weights and combinations of these technologies.

[0011] Market research indicates a strong preference by users for machines that use weights as the active resistance element. The smooth and even operation of well-designed weight machines has been the key to their acceptance. Some advanced technology machines based on direct motor drive, as illustrated by U.S. Pat. No. 5,020,794, Englehardt et al., have gained limited acceptance in upscale professional gyms. However, the inherent cost of the components, the electronics and the power requirements to operate such machines have made them uneconomical for the home market.

[0012] While selectable weight stacks, and even motor-driven selectable weight stacks, have been disclosed in the prior art, they suffer from several disadvantages.

[0013] U.S. Pat. No. 5,876,313 (Krull) shows a radial weight selector incorporated into exercise machines. The Krull patent shows selector pins engaged such that all the weights that are selected are engaged simultaneously. Although Krull further demonstrates that a single weight stack is not adequate to cover the range of resistance that is required for an exercise machine and illustrates a dual weight stack having weights that are placed side by side to achieve a full weight range, Krull utilizes a bulky and expensive design that requires four guide rods. The rods must be manufactured of a strong metal, be precisely machined to be straight, then mounted precisely. Further, each weight must have low-friction linear bearings to allow the weights to move smoothly along the axis that is dictated by the guide rods. The two stacks placed side-by side require a large footprint. The combined stacks are not likely to fit in the footprint of most common weight exercise machines, thus requiring a complete redesign of such machines.

[0014] Krull teaches a selector assembly that is rotated either by a motor, which is mounted on the selector, or by dropping the assembly onto a set of gears that are rotated mechanically or by a motor. The first solution requires that the motors be lifted along with the weights. This approach is undesirable because of the extra weight of the motors, motor stress, and the difficulties associated with providing power to a reciprocating motor. The second solution, where the selector engages a set of gears in the base, requires a precise alignment of the gears and will likely cause the selector to be misaligned after the completion of a number of cycles during which the selector may be rotated and can ultimately cause a critical failure.

[0015] Other Krull patents disclose exercise machines that address weight selection mechanisms. These also suffer from various disadvantages. These patents include U.S. Pat. Nos. 5,935,048, 5,944,642 and 6,033,350.

[0016] The patents to Lowe (U.S. Pat. No. 6,117,049), Scaramucci (U.S. Pat. No. 6,015,367) and La Lanne (U.S. Pat. No. 3,647,209), as well as U.S.S.R. Patent 1,389,789, are further examples of selectable weight stacks. The La Lanne patent discloses a radial weight selection mechanism; the Scaramucci patent discloses a weight mechanism selected by hooks; the Lowe patent discloses a motor-driven mechanism driving a threaded shaft to select the weights; and the U.S.S.R. patent discloses spring-load radial plungers for the weight selection.

[0017] These patents suffer from the disadvantages of providing relatively complex mechanisms. Moreover, the Lowe patent, which discloses a motor-driven selection mechanism, suffers from the further disadvantage of requiring the motor to be mounted on the weights and for the motor to move, as the weights are lifted.

[0018] As will be explained hereinafter, the present invention combines the use of weights with the ability to remotely select the weights, for example by a motor-driven selector mechanism, while at the same time avoiding the disadvantages of the prior art. The technology also lends itself to mechanized selection of the weight using flexible cables and mechanical dials. An application for such a mechanism is found in commonly available exercise machines where direct access to the weight stack is limited due to the elaborate structure of these machines. Because the resistance is generated by the pull of gravity on the weights, the design is energy efficient and is only marginally more expensive than a conventional, pin-selected weight stack machine.

SUMMARY OF THE INVENTION

[0019] An object of this invention is to provide an exercise machine having remote and programmable resistance selection.

[0020] A further object of this invention is to provide an exercise machine having a motor-driven selector for selecting the weights in which the motor does not move with the weights as the weights are raised or lowered.

[0021] Another object of this invention is to provide an exercise machine with nestable, multiple weight stacks that are selectable by engaging a single lift pin pair to select each weight of a weight stack.

[0022] The exercise machine of this invention uses weights as a resistance against which the various muscles are exercised. Although not limited to a particular market, the goal is to provide a machine that can be economically offered to the home market while still providing the advantages of more expensive exercise machines. One advantage is to provide an exercise machine with programmable resistance capabilities. In an exercise machine with programmable resistance capabilities, the user can select the desired resistance through a panel from the seat. A complete workout can be pre-programmed and the user follows the machine in “Automatic” mode very much like working with a personal trainer. By automating the resistance selection, the exercise machine can be programmed remotely (for example, from a personal computer or from the Internet). This allows the exercise machine to become part of a comprehensive regimen of diet and exercise, which may be planned by experts (or expert software). The exercise machine with programmable resistance capabilities also allows the actual performance of the user to be fed back to the regimen planner for follow-up modification or to display the actual execution in comparison with the original plan.

[0023] To accomplish these and other objects an electronically selectable exercise machine has a coupling mechanism such as a handle connected to a cable at its proximal end arranged to transfer a resistance to a user of the electronically selectable exercise apparatus. The machine includes a lifting plate connected to the cable at its distal end and one or more sets of weights arranged in stacks. A motor-driven selector is provided which is arranged to engage one weight in each stack. Since the weights are stacked on each other, if the selected weight is lifted, all the other weights of that stack disposed above the selected weight are lifted simultaneously by the plate. The motor is located such that it does not move with the weights as the weights are raised or lowered. In a particularly advantageous arrangement, two sets of stacks are provided which are nested together to reduce space. The weights of each stack can reciprocate vertically along two guide rods.

[0024] Each weight of each stack has an opening or cavity receiving one of the guide rods. A selector in the form of a cylindrical member is also disposed in this opening.

[0025] The selector also includes two sets of lifting pins. The weights have tabs, each weight of a particular set having a uniquely oriented set of tabs. The selector has a set of unique angular positions, the number of positions being equal to the number of weights in a stack plus one. In each of its positions except one, the selector then engages the tabs of one of the weights. As the selector is lifted, it lifts with it the weight corresponding to the current position of the selector and all the weights disposed above that particular tab. The selector is rotated to a predetermined angular position when the stacks are at the bottom of the equipment. The rotation is accomplished by using stationary motors that may be controlled locally or remotely.

[0026] The exercise machine has a programmable control unit in communication with the motors, and a display that is used to show the current weight setting of the machine and provide other data regarding the operation of the machine. The control unit further includes an input keypad to allow the input of a schedule of resistances provided to said users, and a network interface in communication with a computing system to record a user's progress in exercising and to calculate future exercise regimen.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a side view of a weight lifting machine of this invention.

[0028] FIG. 2 is a cut away plan view of the weight stack used in the machine of FIG. 1 taken along line 2-2.

[0029] FIG. 3 is a perspective view of the weight lifting machine of this invention.

[0030] FIG. 4 is a cut away view of the weight stack of the machine of FIG. 1 taken along line 4-4.

[0031] FIG. 5 illustrates an enlarged perspective view of the weight stack and details of the selector mechanism.

[0032] FIG. 6 is a top view of the secondary weight stack of this invention.

[0033] FIG. 7 is a cut away view of the weight stack of FIG. 6 taken along line 7-7.

[0034] FIG. 8 illustrates the weight stack with one large weight plate and two small weight plates selected according to this invention.

[0035] FIG. 9 illustrates the weight stack with five large weight plates and six small weight plates selected according to this invention.

[0036] FIG. 10 is a block diagram of the electronic control and display circuit for the programmable weight lifting machine of this invention.

[0037] FIG. 11 is a cross sectional view of a weight plate showing the lifting ring and lift tabs of this invention.

[0038] FIG. 12 is a diagram of a lift tab of this invention.

[0039] FIG. 13 is a perspective view of the weight selector of this invention.

DETAILED DESCRIPTION OF THE INVENTION

[0040] FIG. 1 shows an exercise machine 100 of this invention incorporating a selectable weight stack 101. The user pulls on handle 105 that is connected at the proximal end of a cable or similar elongated member 110 to the weight stack 101. The machine 100 further includes a control unit 102 having a user display panel 103. The control unit is connected to a drive unit (discussed in more detail below, in conjunction with FIG. 3) that is used to select the “weight” to be lifted. Usually, at least some of the weights of the weight stack 101 in accordance with a choice made by the user will be selected. However, where only minimal weight is desired, the user may select only the top plate of the weight stack and not the weights, per se.

[0041] As shown in more detail in FIG. 3, the machine 100 includes a vertical post 106 with a longitudinal guide bar 119. The post 106 supports a horizontal plate 108. Plate 108 supports two pulleys 117, 118. The machine 101 further includes a base 158 which supports the post 106 as well as two vertical guide rods 111, 112.

[0042] The weight stack 101 consists of weights which are selectively coupled to a plate 113 as discussed in more detail below. The stack 101 is arranged and constructed so that it is movable vertically up or down along the two guide rods 111, 112 and guide bar 119. The cable 110 is trained over pulleys 117 and 118 and then passes through a hold in plate 108. It then extends downwardly between the guide rods 111 and 112 and is attached to the plate 113 of stack 101 by a hook 114 at the distal end of the cable. As the user pulls on cable 110 with handle 105, the cable 110 forces the plate 113 and any weights attached thereto to rise. Thus the force exerted by the user on the handle is determined by the number of weights attached to the plate 113 (as well as the weight of the plate 113 itself). As the user allows the handle to move back toward the plate 108, the plate 113 and weights attached thereto are lowered toward the base 158. Bushings 115 and 116 attached to plate 113 are provided and act as linear bearings, to reduce the friction between the guide rods 111 and 112 and the lift plate 113, as the weight stack is raised and lowered.

[0043] FIG. 2 provides a horizontal cross sectional view of the weight stack 101, looking downwardly just below plate 113 and FIG. 4 shows a vertical cross sectional view of the weight stack 101. As can be seen in these Figures, the weight stack 101 includes plate 113, a set or plurality of vertically aligned outer weights 121 forming an outer weight stack, a set or plurality of vertically aligned inner weights 122 forming an inner weight stack and two selectors 141, 150. The selectors 141, 150, disposed in cavities or passageways in the weights (one such cavity or passageway being shown in FIG. 7), are used to selectively couple some or all of the outer and inner weights 121, 122 to the plate 113.

[0044] As seen more clearly in FIG. 2, each outer weight 121 has a round opening for a corresponding inner weight 122. Both weights 121, 122 are free to move vertically, independently of each other, along rods 111, 112. Both weights 121 and 122 are prevented from rotating about their respective vertical axes by guide bar 119, guide notch 129 (formed in the inner weight 122) and guide notch 129A (formed in outer weight 121). While the inner weights 122 are generally circular in shape, each outer weight has a somewhat oblong configuration, with straight sides 502 and curved ends 504 and 506. End 504 defines a greater radius of curvature than end 506. This shape advantageously presents a center of gravity for the weight at guide 111, thereby preventing binding as the outer weights are raised or lowered about the guide.

[0045] As seen in FIG. 4, selector 150 has at its top end a lip 128 which rests on bushing 116. The bushing 116 is made of a low-friction material such as nylon, and allows the selector 150 to rotate freely with respect to the lift plate 113 and guide rod 112. Selector 141 has a similar lip 115A resting on bushing 115. Bushing 115 is also made of nylon and allows the selector 141 to rotate with respect to the plate 113 and guide rod 111. Lip 128 is positioned to abut the top surface of plate 113. Accordingly, as plate 113 is raised by a user pulling on cable 110, the plate lifts selector 150 which, in turn, allows the user to raise the weights selected by selector 150.

[0046] Details of the selector mechanism used to select the weights coupled to the plate 113 are now described in conjunction with the Figures. As shown in FIG. 13, the selector 150 consists of a cylindrical wall 150A on which there are mounted an array of lift pins 142. The array is partitioned into two sets of diametrically opposed pins 144a and 144b. All pins 144a are vertically aligned and all pins 144b are vertically aligned along the surface 150A as shown. In addition each pin 144a is aligned horizontally with a respective pin 144b. The vertical spacing between the pins 144 in the array 142 matches the height of the weights 121,122 in the stack 101.

[0047] Each inner weight 122 includes a tab ring 125. As shown in FIGS. 5 and 11 the tab rings 125 are press-fit into holes 121A of the respective weights 122 from their respective underside. Due to a slight taper (shown somewhat exaggerated in FIG. 11), each ring 125 is wedged onto the respective weight 122. Each tab ring is provided with two tabs 126a, 126b diametrically opposed to each other. The tab ring 125 defines a hole 126c for the selector 150.

[0048] When the selector 150 is inserted through the hole 126c, two appropriately aligned lift pins 144a, 144b register with the tabs 126a and 126b on tab-ring 125. Therefore, when the selector 150 moves up, it lifts the weight 122 with it through the tabs 126a, 126b.

[0049] FIG. 12 shows details of the tabs 126a and 126b of FIGS. 5 and 11. Tab 126a is formed of a structural material such as steel to be able to support the entire weight stack 101. For example, this weight may be 300 lbs. or greater. To support the weight of the stack the lifting tab should have a width W1 of approximately 1.5 times the diameter of the selector pin. For example, a 300-lb. weight stack requires a 0.250″ selector pin, thus the lift tab 126a is approximately 0.4″. To make the lift pins 144a, 144b self-securing, a seating notch 128 is formed in the lifting tab 126. The seating notch 128 must be wide enough to accommodate any tolerances in the alignment of the selector pin. Therefore, the seating notch 128 should be at least 20% larger in diameter than the selector pin. In the case described above the width W2 of the notch is approximately 0.3″ in diameter. The outer weights 121 are provided with identical tab rings and tabs to match lift pins on selector 141.

[0050] FIG. 7 provides a sectional view of inner weight stack 129 comprised of inner weights 122, each inner weight 122 being nested in a corresponding outer weight 121 (see FIG. 2). As can be seen in FIG. 7, the tabs 126a of each inner weight 122 are angularly offset from each other.

[0051] More specifically, when observed from the top, the tabs 126a and 126b on the inner weights 122 in the inner stack 129 are shifted 22.5 degrees from each other. If alignment of the tabs 126a and 126b in the top weight is assigned a reference angle of 0 degrees, then the second inner weight from the top will have its tabs 126a, 126b aligned at 22.5 degrees counterclockwise to the reference angle. The third weight is aligned at 45 degrees, and so on. Therefore, the seventh weight is aligned where the angle is 135 degrees.

[0052] Because two tabs 126a, 126b are used in each weight, and these are 18 degrees apart, and if there is no eighth weight, the radial space between the seventh tab and 180 degrees is unused by any of the seven weights.

[0053] Each pair of lift pins 144a, 144b (hidden under the tabs in the tab-ring 125) can engage one and only one of the tabs 126a, 126b as the selector rotates between 0 and 135 degrees. If the selector is set at 157.5 degrees, none of the weight will be engaged.

[0054] Bearing in mind that any weight selected carries with it all the weights above it, it is clear that by rotating the selectors 141, 150 any one of the weights 121, 122 can be selected.

[0055] An advantageous arrangement for the weight stack 101 is obtained if the outer weights 121 are 40 lbs. each, and if the inner weights 122 are 5 lbs. each. This arrangement allows a user to select any weight between 0 and 315 lbs., in 5 lbs. increments (ignoring the weight of the plate 113 and associated hardware, such as the selectors 141, 150).

[0056] FIG. 8 shows the stack 101 with the first or top outer weight 121 selected, as well as the top two inner weights 122. FIG. 9 shows the stack 101 with the top 5 outer weights selected, as well as the top 6 inner weights 122.

[0057] As shown in FIG. 4 and FIG. 5, the selector 150 is positioned on the guide rod 112 and is rotatable around bushing 116 (at the top) and bushing 162 (at the bottom). These bushings 116, 162 allow smooth vertical motion of the selector 150 on the stationary guide rod 112, as well as low-friction rotation of the selector 150 with reference to the guide rod 112.

[0058] The bottom bushing 162 is designed to fit into and engage a dog clutch 152 . Thus when the selector 150 is at rest and is not pulled up by the lift plate 113, it is locked rotationally by the dog clutch 152. In this condition, the weights rest on stop pins 159 attached to the frame 158. To reduce friction, the bushing 162 is coupled to the frame 158 through a ball bearing 156, although other arrangements may be used. For example, ball bearing 162 may be replaced by a low friction bushing.

[0059] The dog clutch 152 is coupled to a sprocket 153 which in turn is engaged to a worm gear 154. Worm gear 154 is mounted on a drive shaft attached to an electric motor 155. Thus, the sprocket 153 is driven by the motor 155 through the worm gear 154 to rotate in reference to the guide rod 112.

[0060] The electric motor 155 is adapted to turn the selector 150 freely through a full rotation, or more, without encountering any resistance other than the friction of the sprocket 153, the bushing 116, dog clutch 152 and the ball bearing 156. Thus, while the selection is being made, none of the weights in the weight stack apply any force on the selector. Because the selection is “weight-free,” small stepper motors may be used. This not only decreases overall size and weight of the machine as a whole, but also decreases costs. Selector 141 for the outer weights is supported in an identical manner and is rotatable by a separate motor 160 (shown in FIG. 10).

[0061] It should be noted that the motor, worm gear and sprocket are located in a position wherein these components are not moved, i.e., they are not lifted, as the weights are raised or lowered. Thus, there is no need for the motor to be mounted on the weights which is often deleterious to motor operation over many repetitions of the machine.

[0062] Thus by rotating the selectors 141 and 150 one pair of lift pins 144 on each selector is placed under the lift tabs 126a and 126b of one of the weights 121, 122. The selected weight(s) and all weight disposed upon the selected weight(s) from the weight stack 101 are coupled to the lift plate 113 through the respective selector 141 or 150. When a user pulls on the cable 110, the lift plate 113 and the selected weight(s) of the weight stack 101 are raised and lowered through an exercise cycle.

[0063] The desired weight of the weight stacks 101 and 121 are selected in each stack by placing the selector at the desired rotational angle. This is achieved by energizing the electric motors 155 and 160 that are associated with each stack 101 or 129 for the proper length of time, so that each motor moves from its current position to the new position.

[0064] The motors 155 and 160 in one implementation are servo motors that receive control signals indicating an amount of rotation necessary to select the desired weight from the weight stacks. The application and design of servomotors for such uses as shown are well known in the art and not discussed further.

[0065] In a preferred implementation, the motors 155 and 160 are stepper motors such as model Z26440-12 manufactured by Haydon Switch and Instrument, Inc. This motor rotates 7.5 degrees for each pulse it receives. With the worm gear reduction set at 1:40 gear ratio, 120 pulses are required to rotate the sprocket 153 by 22.5 degrees. It is thus a simple matter to those schooled in the art of electronic control circuits to provide an electronic controller that will position each of the two selectors 141 and 150 at the desired weight selection.

[0066] The selector 150 and the indexing sprocket 153 are locked rotationally only when the selector 150 is resting against the sprocket 153.

[0067] With reference to FIG. 5, sensor 161 is a proximity sensor mounted through bracket 162 mounted on frame 158. The proximity sensor 161 is positioned so that it is within 5 millimeters from the bottom of the bushing 163. In particular, the proximity sensor 161, such as a proximity photo-microsensor EE-SB5 from Omron Electronics LLC, provides an output when a reflecting surface is within 5 millimeters from the face of the sensor. When the selector 150 is seated against the indexing sprocket 153, the lower bushing 163 is lined up with the position sensor 161. When the selector 150 is pulled up from its rest position, the bushing 163 is disposed away from the sensor 161 and the output of the sensor 161 indicates to the control circuitry (not shown) that the selector 150 is not in place and that the motor 155 should not be activated.

[0068] By placing a notch in the lower bushing 153 at a height that is aligned with the position sensor 161 when the selector 150 is at its rest position against the indexing sprocket 153, the “home” position of the sprocket 153 can be detected by the position sensor 161. When the stepper motor 155 rotates the sprocket 153, the output of the position sensor 161 is monitored. As the notch passes in front of the sensor 161, the reflection from the surface of the bushing 163 is momentarily reduced due to the groove in its surface. The controller detects this change in the output of the position sensor 161, and the “home” position is confirmed. The sensing of the “home” position is useful to prevent cumulative errors between the controller and the actual position of the sprocket 153.

[0069] A single-cable pull exercise system is inherently imbalanced. Because the ratio of the weights selected in the two stacks can be any combination of weights, it is not possible to locate the hook 114 to precisely compensate for this imbalance. In order to allow for a smooth operation of the weight stack, the bushings 116, 163 act to prevent the plate 122 from tilting under such imbalance conditions.

[0070] FIG. 10 shows diagrammatically the electronic control unit 102 of the exercise machine of this invention. The control unit 102 is connected to the exercise machine 100 to provide selection signals to the motors 155 or 160 to select the desired weight from the weight stacks as described above. The position sensors 161 associated with selectors 141 and 150 transmit the position signals 215, 220 to the control unit 102 indicating the “home” position and “rest” position of each selectors 141 and 150.

[0071] The control unit 102 includes a microprocessor to receive the position signals 215 and 220 and generates encoded signals required to select the desired weights from the weight stacks. The microprocessor 200 contains a memory or storage device to retain an exercise regimen for one or more users. The microprocessor 200 is connected to motor driver 205 which receives from the microprocessor the encoded signals designating the weight to be selected. The motor driver 205 processes the encoded signals and generates the respective selection signals 225 or 230 that drive the motors 155 and 160 to select the desired weights. The selection signals 225, 230 cause the motors 155, 160 to rotate the selectors 141, 150 to place one pair of lifting pins 142 under the lifting tabs of the desired weight. Once a weight is selected in this manner, pulling on that weight automatically lifts all the other weights disposed that particular weight in the respective stack. It should be appreciated that the nesting of the two sets of weights allows the device to select one set of weights from each stack independently.

[0072] The physical interface to the user is the user control panel 103. The user control panel 103 as shown is exemplary. Generally, the control panel 103 has a keypad 235 or keyboard to act as an input device, such that the user can provide the desired weight amounts or program an exercise regimen. The control panel 103 has a display 240 (a three digit alphanumeric display in this example) to indicate the weight amount or regimen step.

[0073] In operation, the user enters the desired weight on the keypad 235. The display 240 shows the value of the weight just entered, in a flashing mode, while the motors 155 and 160 move the respective selectors to the desired positions. Once the selectors have reached the desired positions, the display 240 stops flashing.

[0074] The three LED's 242, 244, 246 in the user control panel 103 are used to provide feedback to the user as to the status of the machine. The green LED 246 is lit when the machine is ready to be used for exercise. The yellow LED 244 is lit while the motor 155 and/or 160 is stepping the selector to a new setting or whenever one of the selectors is not in its rest position. The red LED 242 indicates an internal fault in the machine.

[0075] The control unit 102 optimally may have a network interface 210 to allow communication of the microprocessor 200 to a personal computer 250 or with a communication network 255 such as the Internet. The network interface 210 allows updating of the program stored in the memory of the microprocessor. Alternately, the personal computer 250 or communication network 255 gives the necessary instructions to change the weights. This structure further allows a physical trainer or an expert system to direct and monitor multiple users through the network interface of multiple exercise machines.

[0076] It will be appreciated that the weight lifting machine provides numerous advantages over the prior art. For example, it provides a weight stack that is compact, having a reduced footprint, yet one which nonetheless provides a broad range of weight selection. Selection of the weight is precise and errors in selecting the weight are minimized. The construction also provides smooth operation as the weights are raised and/or lowered.

[0077] While this invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention. For example, while the embodiment shown describes an exercise machine in which weights are raised or lowered, it will be appreciated that the principles of the invention are applicable to other types of exercise machines in which various weights are selected by the user.

[0078] One of the advantages of an electrically controlled weight stack is that the user may change the weights from different locations around the machine. In multi-function exercise machines, for example, the user may use a “lat” pull down where he faces the weight stack, and then switch to a leg extension where he faces away from the stack. As the exercise sets proceed, weights need to be changed (usually increased after each set), which would require getting up from the seat and reaching for the weight-selecting pin in a mechanical weight machine.

[0079] It will be appreciated that the electronically controlled machine of the present invention advantageously may allow the use of a portable display/keypad that may be moved with the user, thus making the weight selection within reach at all times. Optionally, an RF link may be used between the display and the controller of the exercise machine. Such technology is readily available and can be used to replace a wired network, although it is contemplated that further advances in this technology will make such linkages even smaller (and perhaps worn by a user as a watch-like display) in the future.