ISOMETRIC AND ISOTONIC EXCERCISER WITH VARIABLE RESISTANCE

Abstract: An exercise device wherein an electrically controlled system (100) provides variable resistance to a cable that is opposed by the operator pulling on an extending cable (6a and 6b) and associated bar (7). Rotating knob (38) allows an operator to vary the force necessary to extend the cable, and control switch (31) establishes the mode of excercise as either isotonic or isometric. As the cable is extended in the isotonic mode a continual force acts to keep the cord taut such that the cable is retracted when there exists slack in the line.

Description: 1 ISOMETRIC AND ISOTONIC EXCERCISER WITH VARIABLE RESISTANCE 2 H 3 4 BACKGROUND OF THE INVENTION 5 Related Applications 7 ° This application is a continuation-in-part of United 9 States Patent Application Serial Number 335,911 filed 10 December 30, 1981. 11 12 Field of the Invention 13 1 This invention relates to exercise apparatus and 15 particularly to apparatus which provides preset resistance 1° in a controlled range of motion. 17 Description of the Prior Art 19 20. Many prior art devices are available for practicing 21 resistance exercises, including such devices as barbells and weight machines in which the exerciser performs a 23 variety of constrained motions by pushing or pulling on 24 bars, handles attached to cables, or similar structures. 25 In other types of exercising devices, the resistance is 26 provided by springs, or hydraulic or pneumatic pressure. 27 still another approach is to pull a rope through a device 28 which applies frictional resistance to the motion of the 29 rope. Exercises performed with each of the above devices 30 are referred to as isotonic because they are performed 31 over a range of motion. 32 33 Another type of exercise where force is applied but 34 no motion occurs, is referred to as isometric. Examples 35 of isometric exercises include standing on one end of a 36 rope and pulling on the other end, or grasping a rope in 37 both hands and pulling the rope. When performing this 38 type of isometric exercise, a tension measuring device may be attached to the rope to provide an indication of the effort exerted by the exerciser. The usefulness of a particular exercise device is determined among other things by the variety of exercises that can be performed, the range of resistance that can be applied, mode of exercise (i.e. isometric or isotonic), cost, control of speed of motion, durability, convenience of location and overall weight. it will be obvious in light of the teachings of this specification that this invention combines all of these factors to provide a significant improvement over prior art exercise devices. SUMMARY in accordance with.this invention ah exercise machine is provided which includes an electrically controlled means for locating with negligible resistance a bar or handle attached to one or more cables at any desired position in preparation for exercise. The structure of this invention allows exercise to be performed isotoni- cally by pulling against the bar or handle with a force such that no motion of the bar or handle occurs unless the force exceeds a preset value. In accordance with a feature of this invention, after the bar or handle, and thus the cable has been pulled, the structure of this invention causes the cables to be automatically retracted once the cables become slack, although no perceptible retraction force is exerted as long as the cables are held slightly taut by the exerciser. in accordance with another feature of this invention, the structure of this invention provides means for clamping the cables to prevent their movement in order that isometric exercises can be performed at any preset handle position. During isometric exercises, the structure of this invention provides a signal (e.g. a light or a bell) which is emitted when the exercise tension applied to the cables exceeds a preset value. in one embodiment of this invention, the electrically controlled means for locating is contained in a housing with one or more cables emerging from the top of the housing. A bar is attached to the cables enabling the performer to exercise by standing on the top of the housing and grasping and applying force to the bar attached to the cables. in another embodiment of this invention, the cables emerge from a housing and are attached to the waist of a swimmer. In another embodiment of this invention, the cables emerge from the housing and are attached to the waist of a runner. BRIEF DESCRIPTION OF THE DRAWING Figure 1 presents one embodiment of this invention in which is shown a platform with two cables 6a, 6b emerging from two sides 4-2 and 4-4 of the platform and attached to the ends of bar 7; Figure 2 depicts the structure of Figure 1 in which two upright supports have been added; Figure 3 shows the arrangement of the cables within the housing for the embodiments shown in Figures 1 and 2; Figure 4 shows in detail the control mechanism within dotted line enclosure A of Figure 3; OM Figure 5 shows one embodiment of the tension sensing and timing circuitry used during the isometric mode of exercise; Figure 6 shows one embodiment of the electrical means for sensing" tension, establishing direction of wind or rewind, and exercise mode selection; and Figure 7 shows a second embodiment of said electrical means for sensing tension, establishing direction of wind or rewind, and exercise mode selection. DETAILED DESCRIPTION Figure 1 shown a platform 101 of convenient size which, in the embodiment of Figure 1 forms the top side of a box or housing 100. A convenient size for many purposes is a box one foot high by two feet deep by four feet wide. However these dimensions can be varied as appropriate and are not critical. The platform 101 is divided into three sections 1, 2 and 3. Sections 1 and 3 are rigidly fastened to sides 4-1, 4-4 and 4-1, 4-2, respectively of box 100 while section 2 is hinged (via hinges 104) along side 4-1. one end 6b of a cable 6 emerges from a hole 1-1 in section i while the other end 6a of cable 6 emerges from a hole 3-1 in section 3. The cable ends are attached to the ends 7a and 7b of bar 7. Figure 2 shows a second embodiment of this invention which is similar to the embodiment of Figure 1 and which includes upright supports 8a and 8b fixed at each end of platform 101. Cross supports 9a and 9b are clamped at any desired height on the upright supports 8a and 8b to support the bar 7 and thereby to establish the starting position of the exercise. A foot switch 10 in the platform 101 releases the cable 6 allowing the bar 7 to be set at any desired height to start the exercise. A second foot switch 31 establishes the mode of exercise as either isometric or isotonic, as desired. Figure 3 shows the layout of the cable 6 inside the box 100. Pulley 12 directs end 6a of cable 6 to pulleys 14 and 15 and pulley 13 directs end 6b of cable 6 to pulleys 14 and 15. Pulleys 14 and 15 direct the doubled cable to pulley 16. Pulley 16 is mounted on a sensing mechanism not shown in Figure 3 but described later and shown in detail in Figure 4. Still referring to Figure 3, the two ends 6a and 6b of cable, after combining and passing over pulley 16 are wrapped around capstan 17. Capstan 17 (which could be replaced by a winch or any other appropriate structure) is driven through worm gear 18 by a worm 19. Worm gear 18 and worm 19 brake capstan 17 when not being used to rotate capstan 17 in one or the other direction. The sensing mechanism shown in Figure 4 can do several different things, namely, (1) cause the worm to wind the cable 6 up on the capstan 17 when the cable is slack; (2) cause the worm 19 to unwind the cable from capstan 17 allowing one to raise the bar 7 either with or without resistance, as desired, or; (3) cause the worm 19 to be stationary and thereby lock the cable 6 for isometric exercises or when tension in the cable is insufficient to turn on the unwinding means. The sensing mechanism 105 on which pulley 16 is mounted is located within the dotted enclosure A of Figure 3 and shown in detail in Figure 4. Sensing mechanism 105 includes rectangular rod 22 located above and parallel to threaded rod 21. Rod 21 passes through a tapped hole in block 23, with pulley 16 being mounted on block 23. Rod 21 also passes through a clearance hole (i.e. an unthreaded hole through which threaded rod 21 can slide with negligible resistance) in bar 24 which is attached (typically by _OMPI ~v welding) to rod 22. Rod 21 is positioned with respect to block 24 by a spring 25 mounted on rod 21 on one side of bar 24 and by a keeper nut 26 on the other side of bar 24, as shown. Thus, when tension is applied to the cable 6 about pulley 16, threaded rod 21 slides in the direction of arrow 21a through the clearance hole in block 24, thereby compressing spring 25. When tension on the cable 6 is released, spring 25 returns the rod 21 to its original position. When rod 21 slides in the direction of arrow 21a and thus compresses spring 25 due to tension in cable 6, rewind switch 27 is switched from the "slack" position (i.e. when cable 6 is slackened) to the "taut" position (i.e. when cable is taut). When rewind switch 27 is in the slack position, worm 19 (Figure 3) is turned by motor 20 to wind the cable 6 up on capstan 17 (Figure 3) until the cable 6 is slightly taut, whereupon rewind switch 27 (Figure 4) switches to the "taut" position and the worm 19 stops turning. Rectangular rod 22 is fixed, for example by welding to block 24 as shown. Block 24 is pivotally mounted on pin 30 which is rigidly attached to the frame (not shown) of the apparatus. Bar 22 fits into a groove in sliding weight 28. When sufficient tension is applied to the cable about pulley 16, the assembly (rods 21, 22 and bar 24) pivits about pin 30 so as to switch the "lift" switch 29, located at one end of bar 22. This operation of lift switch 29 causes the worm 19 to turn and unwind the cable 6 from the capstan 17 (Figure 3). The amount of tension in the cable 6 (and thus the force on the bar 7) required to unwind the cable 6 is determined by the distance dl between sliding weight 28 and pin 30, as well as by the distance d2 between block 23 and pin 30 and the distance d3 between the pin 30 and the centerline of rod 21. The position of block 23 is changed by turning knob 38. Rotating the threaded rod 21 and causing block 23 to move linearly along rod 21, thus changes distance d2. f OH A "position" switch 10 (shown in Figures 1, 2, 4, 6 and 7) is connected such that if slight tension is applied to the cable 6 and position switch 10 is simultaneously closed, the cable will unwind, thus allowing positioning of the bar 7 (Figures 1 and 2) without resistance. In one embodiment, position switch 10 is a foot operated switch located on the platform 101 as shown in Figure 2. Also located in the platform 101 (for example, as a foot switch similar to switch 10, previously described) is a "mode" switch 31 which is used to switch the equipment to either the isometric mode or the isotonic mode (see Figures 1 and 2). In the isometric mode, switch 31 causes lift switch 29 to be connected to isometric timer (not shown in Figure 4 but described later), cable 6 to be locked in a fixed position and lift switch 29 to be con- nected to the cable drive circuitry (not shown in Figure 4 but described below). Referring now to Figure 5, there is presented one embodiment of an isometric timer 110 for defining the length of time of each isometric exercise. Isometric timer 110 includes timer motor 32 with cam 33 mounted on the shaft of timer motor 32. In one embodiment, cam 33 is a disk with two removable screws (not shown) on its periphery, with the screws causing switch 34 to operate as cam 33 is rotated and with the angular separation of the two screws defining the isometric timing interval. If switch 34 is in the reset condition when the mode switch 31 is first switched to isometric and cable 6 is slack so that switch 29 is in the "no lift" position, the green light 36 will come on indicating that the timer motor 32 is turning so as to switch 34 to start. At this point, the motor 32 and lights 36 are both off. When the exerciser exerts enough tension to switch 29 to lift, timer motor 32 and red light 35 turn on. Motor 32 turns until the cam moves switches 34 to reset at which time the red light _C FI goes off. When the cable goes slack, switch 29 switches to no lift causing the green light to come on (signaling completion of the lift cycle) and the motor to drive switch 34 back to start, ready for the next exertion. In light of the teachings of this specification, it is obvious to those skilled in the art that other circuits could be devised which, operated in conjunction with a lift switch and mode switch as described above, would perform similar or related services for the user. When the mode switch 31 is switched to the isotonic position, the lift switch 29 is connected into the wind- unwind circuitry (not shown in Figure 5). The function of this wind-unwind circuitry is to provide the wind-unwind functions described above, i.e. unwind cable 6 from capstan 17 when strong tension is applied to cable 6 in excess of the preset tension, wind cable 6 onto capstan 17 when the cable 6 is slack, and maintain cable 6 in position when only slight tension is applied to cable 6. one embodiment of the wind-unwind circuitry of this invention is shown in Figure 6. When rewind switch 27 is i the wind position, (i.e. cable 6 is slack) three pole double throw relay 37, connected to the windings of capstan motor 20, turns on capstan motor 20 so as to wind the cable 6 up on capstan 17. When the cable 6 becomes suffi- ciently taut so as to cause rewind switch 27 (Figure 4) to be moved to the taut position, relay 37 is turned off. hen relay 37 is off, power to the capstan motor 20 is disconnected thereby causing capstan motor 20 to stop and thereby locking the cable 6 fixed. By the operation of relay 37, power connections to the windings of capstan motor 20 are now reversed so that if cable 6 is pulled taut enough (i.e. greater than or equal to the preset tension value set by adjusting the position of weight 28 on rod 22), lift switch 29 is moved to the lift position, Cr P thereby connecting relay windings 38 in series with rewind switch 27 (which is in the taut position), thereby acti- vating single pole single throw relay 38. Capstan motor 20 thereby turns on so as to unwind the cable 6 from the capstan 17. Position switch 10 is connected in parallel with lift switch 29 thus providing that if the cable 6 is taut (i.e. switch 27 in the taut position), and position switch 10 is closed (i.e. by the performer indicating that a no resistan change in the height of bar 7 is desired), the cable will unwind enabling the bar 7 to be positioned without resistanc Another embodiment of the wind-rewind circuitry of this invention is shown in Figure 7. Worm 19 is driven either by wind motor 39 or by unwind motor 40. If desired, either one or both the wind and unwind motors 39, 40 are connected to a source of power through a speed controller, thus allowing the winding and unwinding of cable 6 on capstan 17 at a selected one of a large number of possible speeds. In Figure 7, speed controller 41 is shown connected between a source of power and unwind motor 40. When mode switch 31 is set in the isotonic mode, lift switch 29 controls the unwind motor 40. When tension in the cable 6 is sufficient to cause switch 29 to be set in the lift position, motor 40 unwinds the cable 6 from capstan 17. Conversely, when the cable 6 is slack, wind switch 27 closes to the slack position thus causing wind motor 39 to operate to wind up the cable 6 on capstan 17, thus removing the slack from cable 6. One problem associated with the use of capstan motor 20 (Figure 6) and wind and unwind motors 39, 40 (Figure 7) is that under some conditions of usage the motors are required to very suddenly reverse their direction of rotation. In order to reduce the rather large surge currents that occur with some motors due to this sudden ( OMPI reversal of the direction of rotation, a number of solutions are available, which are suitable for use in both the embodiments of Figures 6 and 7. One means to minimize the surge current is to use a so-called "instant reversing motor" for motors 20 (Figure 6), 39 and 49 (Figure 7). These motors are manufactured by General Electric. They are more expensive than other types of motors, such as the split phase capacitor start motor and the universal AC-DC motor. Another means to minimize the surge current is to encapsulate spring 25 (Figure 4) in a damping medium such as silicone putty (for example, the widely known Silly Putt material, or a heavy grease), which dampens the motion of spring 25 so as to slow the movement of rod 21 as it goes from the lift mode to the rewind mode, thereby giving the motor 20 (in the embodiment of Figure 6) and motors 39 and 40 (in the embodiment of Figure 7) time to stop before reversing. Typically, it is desirable to provide a minimum of approximately 100 milliseconds between motor rotation in one direction and motor rotation in the opposite direction. Still another means to minimize surge currents is to attach to the worm shaft a brake (not shown) which brakes the worm shaft when no power is applied to the motors 20, 39 r 40. However, although brakes are well known to those of ordinary skill in the mechanical arts, the use of brakes is rather expensive. Yet another means to minimize surge currents is the use of a "rotation detector" on the worm shaft. Such a rotation detector prevents application of power to cause the winding action so long as the worm shaft is turning in the unwind direction, and vice versa. Referring to Figure 8, rotation detector 120 is shown in which a band 41 is held astride the worm shaft 42 by opposing anchor springs OMP 43a and 43b. When the worm shaft 42 rotates in the clock- wise direction (as indicated by the arrow and corresponding to the winding of cable 6 on to capstan 17), friction causes the band 41 to tend to rotate with worm shaft 42 thereby switching motion switch 44b which thereby prevents power from being applied to the timer motor 20 (Figure 6) or unwind motor 40 (Figure 7) thus preventing the counter- clockwise drive of worm shaft 42 (corresponding to the unwinding of cable 6 from capstan 17) until the clockwise rotation of worm shaft 42 has ceased. Conversely, when worm shaft 42 rotates in the counter-clockwise (i.e. unwind) direction, the band 41 tends to rotate with worm shaft 42 thereby switching motion switch 44a which thereby prevents power from being applied to the timer motor 20 (Figure 6) or the wind motor 39 (Figure 7) thus preventing the clockwise drive of worm shaft 42 until the counter- clockwise rotation of worm shaft 42 has ceased. In this manner, surge currents are minimized. The embodiments of this invention described above include the use of capstan 17 which winds, unwinds or clamps the cable 6, as desired. It is emphasized that means other than capstan 17 provide additional embodiments of this invention. For example, in Figure 9 another embodiment of this invention is shown, which includes threaded rod 45 which is supported at one end by a bearing 46 held in a fixed support 47. Threaded rod 45 is coupled at its other end to a reversible motor 48. The rod 45 is threaded through a movable support 49 with pulleys 50A and 50B being mounted on movable support 49. The ends of two cables, 51A and 51B are anchored on fixed support 47 as shown. The cables 51A and 51B pass around pulleys 50A and 50B, respectively, and then around fixed pulleys 52A and 52B, respectively. The two cables 51A and 51B then pass on to a tension sensing mechanism (not shown), such as the tension sensing mechanisms previously described in the foregoing paragraphs, and are in turn connected to a CMF handle, also as described in the previous embodiments. When the tension on the cables 51A, 51B exceeds a preset value, the motor 48 turns on and the movable support 49 moves toward stationary support 47, thereby causing the cables 51A, 51B to "play out", which is analogous to the unwind operation of the previously described embodiments. When the cables 51A, 51B are slack, the motor 48 turns on in the opposite direction causing the movable support 49 to move away from fixed support 47 and thus the slackness of cables 51A, 51B is removed which is analogous to the wind operation of the previously described embodiments. When the motor 48 is not turning, the threaded rod 45 prevents movement of (i.e. "locks") the cables 51A, 51B. The embodiment of Figure 9 is suitable for use with a low cost motor 48, such as the universal AC-DC type which is, if desired, powered by an inexpensive speed controller of well known design (not shown). Furthermore, the embodiment of Figure 9 provides a substantial reduction in the cost of gearing as compared with the embodiments of Figures 3 and 7 which utilize the worm drive worm gear-capstan structure. i the above described embodiments of this invention, the use of the tension sensing and wind-unwind circuitry W as described in conjunction with a platform upon which the exercise performer stood or laid to perform his exercise routine. It is obvious to those of ordinary skill in the art, in light of the teachings of this invention, that other embodiments can be easily designed in which the cable emerging from the wind-unwind means is arranged to accommodate exercise routines unique to a particular sport. For example, referring to Figure 10, an embodiment of this invention is shown providing a cable 53 having one end attached to the waist of a swimmer 54 and its other end emerging from the tension controlling mechanism 55. The use of the device for swimmers constitutes a con- C FI siderable improvement over such prior art means as kick- boards, which are presently used to provide added resistance to swimmers. Similarly yet another embodiment of this invention (not shown in the drawings) provides a cable attached to the back of the waist of a runner such as a football lineman to strengthen his charge. The above descriptions are meant to be illustrative only and are limiting. Other embodiments of this invention will be obvious to those skilled in the art of designing exercise machines in view of the above disclosure. _O FI ' "

Claims: I CLAIM: 1. A structure for assisting a person to perform exercises comprising: means for winding and unwinding a cable; means for providing a hand or other hold for said person; cable means connected between said means for winding and unwinding and said means for providing a hand or other hold; and means for controlling said cable means such that said cable means is unwound from said means for winding and unwinding when the tension exerted on said cable means exceeds a first pre-defined value, said cable means is wound on to said means for winding and unwinding when the tension exerted on said cable means is less than a second pre-defined value which is less than said first predefined value; said cable means is unwound without substantial resistance from said means for winding and unwinding when the tension exerted on said cable means exceeds said second pre-defined value and a release mechanism is simul- taneously activited; and said cable means is held fixed in position at all other times. 2. Structure as in claim 1 including means for emitting a signal when the tension exerted on said cable means exceeds a pre-defined value and said cable means is held fixed in position. 3. Structure as in claim 2 wherein said means for winding and unwinding comprises a capstan, and said means for controlling comprises; reversible motor means including a motor shaft; and means for coupling said capstan to said reversible motor means; wherein said cable means is wound by winding said cable means on said capstan and said cable means is extended by unwinding said cable means from said capstan. 4. Structure as in claim 3 wherein said reversible • motor means comprises a first motor which, when energized, causes said capstan to rotate in a first direction of rotation and a second motor which, when energized, causes said capstan to rotate in a second direction of rotation opposite said first direction of rotation. 5. Structure as in claim 3 wherein said means for coupling comprises a worm wheel affixed on said capstan and a worm gear affixed on said motor shaft, wherein said worm gear and worm wheel serve as a brake on said capstan when power is not applied to said reversible motor means, thereby holding said cable means fixed. 6. Structure as in claim 2 wherein said means for controlling comprises a movable support having a threaded hole; a rotatable pully means attached to said movable support for rotably passing said cable means; a fixed support; a threaded rod having a first end and a second end, said first end attached to said fixed support, said threaded rod being threaded into said threaded hole of said movable support and said cable means being rotably tensioned by said movable support, and means for rotating said threaded rod, wherein said movable support moves in a first linear direction in response to the rotation of said threaded rod in a first direction of rotation, thereby to decrease the tension on said cable means, said movable support moves in a second linear direction opposite said first linear direction in response to the rotation of said threaded rod in a second direction of rotation opposite said first direction of rotation, thereby to increase the tension on said cable means, and holds said cable means at 1 a selected tension when said threaded rod is not rotated. 2 3 7. Structure as in claim 3 which further includes 4 means for controlling the direction of rotation of said 5 reversible motor means comprising: 6 7 a pivot block which is rotatably mounted about a 8 pivot axis, said pivot block having a pivot block through- 9 hole aligned perpendicular to said pivot axis; 10 11 a sliding rod means having a portion slidably 12 mounted within said pivot block throughhole; 13 14 bias means for establishing the rest position of 15 said sliding rod means relative to said pivot block; 16 17 a first slidable block capable of being secured 18 at a desired position along the length of said sliding rod 19 means; 20 21 a fixed rod connected to said pivot block and 22 substantially parallel to said sliding rod means; 23 24 a second slidable block capable of being secured 25 at a desired position along the length of said fixed rod; 26 27 means for transmitting energy from said cable to 28 said first slidable block, wherein as the tension in said 29 cable increases, said slidable rod moves with respect to 30 said pivot block in opposition to the force supplied by 31 said bias means, and wherein, as said tension in said 32 cable increases, further rotates said sliding rod means, 33 said fixed rod, said first and second sliding blocks, and 34 said pivot block about said pivot axis; 35 36 a first switch means having a first position 37 when said slidable rod means is in its rest position when " 38 the tension on said cable is less than said first pre- defined value and having a second position when said slidable rod means is moved from its rest position when the tension on said cable is greater than said first pre-defined value; a second switch means having a first position when said fixed rod is in its rest position and a second position when said fixed rod is rotated about said pivot axis an amount corresponding to a tension on said cable which is greater than said second pre-defined value, wherein said cable means is retracted when said first switch is in said first position and said second switch is in said first position, said cable means is held fixed when said first switch is in said second position and said second switch is in said first position, and said cable means is extended when said first switch is in said second position and said second switch is in said second position. 8. Structure as in Claim 7 including a third switch in parallel with said second switch for allowing movement of said means for providing a hand or other hold with substantially no resistance when said third switch is closed. 9. Structure as in Claim 7 further including a timer wherein said . timer operates to lock said. cable means in position for a predetermined period of time during which the exerciser maintains a selected tension on said cable means and wherein said timer stops when said pre- determined tension is removed and a warning signal is generated and wherein said timer resets at the end of said predetermined period of time. 10. Structure as in Claim 7 wherein said bias means comprises a spring. O 11. Structure as in Claim 10 wherein said spring is damped by a viscous material thereby causing said reversible motor means to stop rotating before being caused to rotate in the opposite direction. 12. A device for protecting a motor drive against the application of power to drive the motor in one direction when the motor drive is turning in the opposite direction, said device comprising a band of material which straddles the motor shaft and is held in place by springs attached to each end of the band with a switch attached to the other ends of said band so that when the shaft turns in either direction, the band slides around the shaft so as to open the switch which would otherwise drive the motor drive in the opposite direction.

Inventors: SMITH ROBERT S, SMITH, ROBERT, S.
Applicants: SMITH ROBERT S, SMITH, ROBERT, S.
Application year: 1982
Main classification: A63B21
IPC codes: A63B21