Asymmetric force applicator attachment for weight stack type exercise machines

• US 5,476,428 A
• Filed: 03/10/1994
• Issued: 12/19/1995
• Est. Priority Date: 05/20/1993
• Status: Expired due to Term

• Current Assignee: Computer Sports Medicine, Inc.
• Original Assignee: Computer Sports Medicine, Inc.
• Inventors: Burns, Stephen K., Krawiec, Wojciech J., Potash, Richard J., Potash, Robert L.
• Primary Examiner(s): Apley, Richard J.
• Assistant Examiner(s): MULCAHY, JOHN M
• Application Number:
  US08/212,346
• Time in Patent Office: 649 Days
• Field of Search: 482/1-9, 482/97-104, 482/106
• US Class Current: 482/5
• CPC Class Codes: A63B 21/00058 Mechanical means for varying the resistance A63B21/06 takes precedence
• CPC Class Codes: A63B 21/0058 using motors
• CPC Class Codes: A63B 21/0628 for vertical array of weights
• CPC Class Codes: A63B 21/063 Weight selecting means
• CPC Class Codes: A63B 21/154 using special pulley-assemblies
• CPC Class Codes: A63B 2220/34 Angular speed

Abstract

An attachment for a weight stack type exercise machine to pull the weight stack down while it is being lowered, (or to pull on a weight stack lifting means so as to add to the force applied to the lifting means by the weight stack) so that the eccentric exercise force required to lower the stack is greater than the concentric exercise force required to raise it. Such asymmetric exercise forces more closely match muscle strengths, which are normally greater for eccentric exercise than for concentric exercise. The attachment has an electric motor and a control unit including a keypad, a display and a microcontroller. The motor is coupled to the weight stack by an eccentric force control cable or a toothed belt or alternatively is operatively connected so as to apply additional force to the lifting arrangement. The keypad allows the user to select the amount of force added during the eccentric phase of exercise, when the weight stack is moving down. A sensor enables the controller to determine whether the weight stack is moving up or down. As the weights in the stack are being raised, no significant force is generated by the motor and eccentric force control cable or belt. As the weights are being lowered, an amount of additional (i.e. in addition to gravity) eccentric force selected by the user via the keypad is applied to the weight stack or lifting arrangement by the motor via the eccentric force control cable, or to the toothed belt.

Claims

1. In a weight stack type exercise machine having a weight stack and lifting means coupled to an exercise member for manually raising and lowering the stack, the improvement comprising:

a drive motor;

eccentric force control means coupled between said motor and said lifting means for applying a force to said lifting means which varies in accordance with the torque generated by said motor;

sensing means coupled to said lifting means for determining the magnitude and direction of the speed of said weight stack; and

a microcontroller coupled to said sensing means and said motor for varying the torque generated by said motor in accordance with an eccentric force input signal and the output of said sensing means, to cause said eccentric force control means to apply a predetermined force to said lifting means corresponding to said eccentric force input signal when the stack is moving down, the direction of said predetermined force being such that said predetermined force adds to the force applied by said weight stack to said lifting means, the combined forces applied to said lifting means by said weight stack and said eccentric force control means being coupled to said exercise member by said lifting means.

2. The improvement according to claim 1, further comprising a keypad having selection means for generating said eccentric force input signal.

3. The improvement according to claim 1, further comprising display means for indicating the value of said eccentric force input signal.

4. The improvement according to claim 1, wherein said lifting means comprises a toothed belt, and said eccentric force control means comprises a rotatable gear having teeth engaging teeth of said belt.

5. The improvement according to claim 4, wherein said microcontroller causes said eccentric force control means to apply minimal force to said belt when the stack is moving up.

6. The improvement according to claim 4, wherein said microcontroller causes said motor to drive said gear so as to substantially compensate for drag effects due to said eccentric force control means and associated mechanical elements.

13. The improvement according to claim 1, 7 or 12, wherein said microcontroller includes means for reversing the direction of the force applied to the lifting means by the motor when the weight stack is lowered at an excessive speed in a lower range of movement thereof, to slow down the rate of descent of the weight stack and thus minimize damage due to releasing of said exercise member when said weight stack is in a raised position.

7. In a weight stack type exercise machine having a plurality of weight plates, a pair of parallel vertical guide rods for maintaining said plates in vertical alignment, selection/support means operatively associated with said guide rods for selecting and supporting a number of said plates to be included in a weight stack, lifting means for manually raising and lowering the selection/support means and weight stack, and an exercise member connected to a part of said lifting means remote from said weight stack, the improvement comprising:

a drive motor;

force incrementing means coupled to said motor for applying a force to said lifting means which varies in accordance with the torque generated by said motor;

sensing means coupled to said lifting means for determining the magnitude and direction of the speed of said weight stack; and

a microcontroller coupled to said sensing means and said motor for varying the torque generated by said motor in accordance with an eccentric force input signal and the output of said sensing means, to cause said force incrementing means to apply a predetermined force to said lifting means corresponding to said eccentric force input signal only when the stack is moving down, the direction of said predetermined force being such that said predetermined force adds to the force applied by said weight stack to said lifting means, the combined forces applied to said lifting means by said weight stack and said force incrementing means being coupled to said exercise member by said lifting means.

8. The improvement according to claim 7, wherein said lifting means comprises a toothed belt, and said force incrementing means comprises a rotatable gear having teeth engaging teeth of said belt.

9. The improvement according to claim 8, wherein said microcontroller causes said motor to drive said gear so as to substantially compensate for drag effects due to said force incrementing means and associated mechanical elements.

10. The improvement according to claim 8, wherein said microcontroller causes said gear to apply force to said belt when said weight stack is moving down at a speed in excess of a predetermined speed limit, the direction of said force being opposite to the direction of movement of said belt.

11. The improvement according to claim 8, wherein said belt partially wraps around said gear so that several teeth of said gear and said belt simultaneously engage each other, and said force incrementing means comprises power transmission means coupled between said motor and said gear.

12. In a weight stack type exercise machine having a plurality of weight plates, a pair of parallel vertical guide rods for maintaining said plates in vertical alignment, a selector bar operatively associated with said guide rods for supporting a weight stack, means for coupling a selected number of said plates to be included in said weight stack to said selector bar, and lifting means for lifting said weight stack, said lifting means having one end connected to said selector bar and another end connected to an exercise member, the improvement comprising:

variable force incrementing means including an eccentric force drive motor and power transmission means operatively connected to said lifting means, for applying a force to said lifting means which varies in accordance with an eccentric force control signal;

sensing means for determining the magnitude and direction of the speed of said weight stack;

input means for generating an eccentric force input signal in response to manual actuation thereof;

means for indicating the selected magnitude of said eccentric force input signal; and

a microcontroller coupled to said sensing means, said input means and said variable force incrementing means for generating said eccentric force control signal to cause said variable force incrementing means to apply (i) minimal force to said lifting means when the weight stack is moving up, and (ii) a predetermined force to said lifting means corresponding to said eccentric force input signal when the weight stack is moving down, the direction of said predetermined force being such that said predetermined force adds to the force applied by said weight stack to said lifting means, the combined forces applied to said lifting means by said weight stack and said variable force incrementing means being coupled to said exercise member by said lifting means.

14. An attachment in combination with a weight stack type exercise machine having a weight stack and lifting means for manually raising and lowering the stack, with an exercise member connected to a part of said lifting means remote from said weight stack, said attachment comprising:

variable force incrementing means including a drive motor and power transmission means operatively connected between said motor and said lifting means, for applying a force to said lifting means which varies in accordance with an eccentric force control signal;

sensing means for determining the magnitude and direction of the speed of said stack;

manually operable input means for generating an eccentric force input signal corresponding to a desired increment of eccentric force to be applied to said exercise member; and

a microcontroller coupled to said sensing means and said variable force incrementing means for providing said eccentric force control signal to vary the force applied to said lifting means by said variable force incrementing means in accordance with said eccentric force input signal and the output of said sensing means, to cause application of a predetermined force to said lifting means corresponding to said eccentric force input signal only when the weight stack is moving in a given direction, the combined forces applied to said lifting means by said weight stack and said variable force incrementing means being coupled to said exercise member by said lifting means.

15. The combination according to claim 14, wherein said microcontroller causes said motor to be driven so that said variable force incrementing means applies minimal force to said lifting means when the weight stack is moving in a direction opposite to said given direction.

16. An attachment in combination with a weight stack type exercise machine having a plurality of weight plates, a pair of parallel vertical guide rods for maintaining said plates in vertical alignment, selection/support means operatively associated with said guide rods for selecting and supporting a number of said plates to be included in a weight stack, and a toothed belt for manually raising and lowering the selection/support means and weight stack, said attachment comprising:

a drive motor;

a rotatable gear having teeth engaging teeth of said belt;

mechanical power transmission means for coupling said motor to said gear to apply a force to said belt which varies in accordance with the torque generated by said motor;

sensing means coupled to said transmission means for determining the magnitude and direction of the speed of movement of a portion of said belt engaged by said transmission means; and

a microcontroller coupled to said sensing means and said motor for varying the torque generated by said motor in accordance with an eccentric force input signal and the output of said sensing means, to cause said transmission means to apply a predetermined torque to said gear corresponding to said eccentric force input signal only when said gear is rotating in a given direction.

17. An attachment for a weight stack type exercise machine having a plurality of weight plates, a pair of parallel vertical guide rods for maintaining said plates in vertical alignment, a selector bar operatively associated with said guide rods for supporting a weight stack, means for coupling a selected number of said plates to be included in the weight stack to the selector bar, and a toothed lifting belt for lifting the weight stack, said lifting belt having one end connected to the selector bar and another end connected to an exercise member, said attachment comprising:

an eccentric force drive motor;

a rotatable eccentric force control gear adapted to engage said toothed belt;

mechanical power transmission means for coupling said motor to said eccentric force control gear to apply a force to said gear which varies in accordance with the torque generated by said motor;

an angular position sensing means coupled to said power transmission means for determining the magnitude and direction of the speed of rotation of said eccentric force control gear;

a keypad for generating an eccentric force input signal in response to manual actuation thereof;

means for indicating the selected magnitude of said eccentric force input signal; and

a microcontroller coupled to said sensing means, said keypad and said motor for varying the torque generated by said motor in accordance with said eccentric force input signal and the output of said sensing means, to apply (i) minimal force to the weight stack via said eccentric force control gear when said gear is rotating in one direction, and (ii) a predetermined torque to said eccentric force control gear corresponding to said eccentric force input signal when said gear is rotating in the opposite direction, so that the combined forces applied to said lifting belt by said weight stack and said eccentric force control gear may be coupled to said exercise member by said lifting belt.

18. In a weight stack type exercise machine having a weight stack and lifting means including a longitudinally movable elongated flexible element mechanically coupled between an exercise member and the weight stack, for manually raising and lowering the stack by application of longitudinal force to said elongated flexible element via said exercise member, the improvement comprising:

a drive motor;

eccentric force control means including said motor coupled to said elongated flexible element for subjecting said lifting means to a longitudinal force, in addition to the longitudinal force exerted on said lifting means by said weight stack, which varies in accordance with the torque generated by said motor;

sensing means for determining the direction of movement of said weight stack; and

a microcontroller coupled to said sensing means and said motor for varying the torque generated by said motor in accordance with an eccentric force input signal and the output of said sensing means, to cause said eccentric force control means to subject said elongated flexible element to a predetermined longitudinal force, corresponding to said eccentric force input signal, when the stack is moving down, said predetermined longitudinal force being in addition to the longitudinal force exerted on said elongated flexible element by said weight stack.

19. An attachment for a weight stack type exercise machine having a plurality of weight plates and an elongated lifting belt for lifting the weight stack, said lifting belt having one end coupled to the weight stack and another end coupled to an exercise member, said attachment comprising:

force incrementing means for applying a variable longitudinal force to said belt, comprising

a motor,

drive means adapted to engage a portion of said belt and apply longitudinal force thereto,

mechanical power transmission means for coupling said motor to said drive means, and

control means for varying said force in accordance with a force increment control signal;

sensing means coupled to said force incrementing means for providing an output signal indicative of the magnitude and direction of the speed of movement of said portion of said belt;

manually operable input means for generating a weight increment signal; and

a microcontroller coupled to said sensing means, said input means and said force incrementing means for generating said force increment control signal to vary said longitudinal force in accordance with said weight increment signal and said output signal, to apply a substantially greater longitudinal force to said portion of said belt when the belt is moving in one longitudinal direction that when the belt is moving in the opposite longitudinal direction, so that the combined forces applied to said lifting belt by said weight stack and said drive means may be coupled to said exercise member by said lifting belt to provide greater exercise resistance when said weight stack is moving down than when said weight stack is moving up.