Resistance system for fitness equipment

A resistance system for an exercise device includes a frame, a resistance element such as elastic bands, coil springs, weight plates, pneumatic or hydraulic cylinders. An interference element such as a plate, chain or one or more links is supported by a support plate mounted on the frame. Selective engagement with the resistance element is provided by actuation of a dial, other actuator or controller or directly by the user. Thereby the resistance element can be selectively engaged or disengaged to vary the resistance to the user.

FIELD OF THE INVENTION

The present invention generally relates to fitness equipment and, more particularly, to a system for altering the resistance in an exercise device.

BACKGROUND OF THE INVENTION

Exercise is becoming more and more of a way of enabling a healthy lifestyle. Resistance or “strength” equipment has repeatedly been shown to provide numerous benefits including increased bone density, increased lean tissue mass and also some cardiovascular benefits. In addition cardiovascular equipment has a wide range of health and fitness benefits. A component to strength equipment is the ability to change the resistance. Not only are some people stronger than others and some muscle groups stronger than others with the same person, but as a user progresses in a strength program preferably the machine provides greater resistance. Therefore the ability to change resistance with any exercise device, especially a resistance or strength machine enhances the usefulness of the device. It is desirable to have ease of use, and high variability in the resistance selection system. This allows minimal down time during training as well as small increments in resistance over a great range to accommodate the largest audience as possible.

It should therefore be appreciated that there is a need for an adjustable resistance setting device that allows for actuation of a dial, other actuator or direct actuation of a resistance system to simply, easily and reliably change the resistance settings in an exercise device. The present invention fulfills this need and others.

SUMMARY OF THE INVENTION

The present invention provides a frame which may include a support plate, a carriage moveably mounted to the frame and plural resistance elements each including a support flange on a first end and a second end coupled to the carriage. An interference element is adapted to enable selective simultaneous engagement with the support flange of more than one resistance elements so that movement of the carriage encounters different resistance to that movement depending upon the resistance elements engaged. The interference element may be supported by the support plate. The resistance element may be a plurality of individual elements of the same or different load producing capabilities. The resistance elements may include elastic cords, weights, pneumatic cylinders or hydraulic cylinders.

An alternative embodiment of the invention includes the elements as previously disclosed, the differences being the interference element is coupled to the carriage and the second end of the resistance elements are coupled to the frame. In this manner, as with the previous embodiment, as the carriage is displaced the resistance elements which are supported by the interference element will generate a load to the user and the resistance elements that do not have their support flanges engaged by the interference element will not generate a load to the user.

The invention may also include an actuation system including a dial or lip adapted to be grasped by a user. The actuation system being coupled to the interference element to enable displacement of the interference element relative to the support flange and therefore the resistance element.

The invention may also include a positioning system coupled to the interference element to enable incremental positioning of the interference element relative to the resistance element. This may include a sprocket mounted to a dial and a spring biased pin engaging with detents in the sprocket. In addition, the positioning system may include a spring pin coupled to the interference element and releasably engaged with a rail secured to the frame.

The support flange of the invention may take on a number of different forms such as an undercut, tab or cap, all similar in function. The support flange may include an undercut adapted to receive the interference element. In some cases the undercut will be open on two sides so as to allow through passage of the interference element.

In a similar manner, the interference element may vary in form though providing the same or similar function. The interference element may be comprised of one or more links mounted to a pliable belt, a plurality of links moveably coupled one to another to form a continuous link, a plurality of links joined together and made into a continuous link by the free ends being joined by a pliable belt or a plurality of links joined to a pliable belt. The interference system may also include a substantially flat plate with at least one slot adapted to receive the support flange. In many cases more than one slot is used and the slots may be notched, thus providing more than one width of an area of the slot. The flat plate may also be semi-pliable and therefore flexible such as could be the case if manufactured from spring steel. Also the interference element may be comprised of a chain with at least one chain ear extending laterally from one side of a chain link, the chain ear adapted to be received by the support flange.

In addition a method of use of the resistance system is disclosed in which the elements of the device are provided, a user positions the interference element relative to the resistance element(s) and moves the carriage. This provides a selected tension for the user to exercise the body.

For the purposes of summarizing the invention and the advantages achieved over the prior art, certain advantages of the invention have been described herein. Of course, it is to be understood that not necessarily all such advantages can be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention can be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following description of the preferred embodiments and drawings, the invention not being limited to any particular preferred embodiments disclosed.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the illustrative drawings, and particularly toFIG. 1, there is shown a device12incorporating a resistance system as it could be used for an exercise machine. This device12has been adapted for resistance by spring resistance cords13. Throughout this disclosure, resistance is illustrated in this form as resistance cords13, but it is understood that any form of resistance may be used with the invention including springs of many types, such as coil springs and elastic cords, weight plates; hydraulic and pneumatic cylinders and fluid systems with controlled flows such as hydraulic dampers or shocks. In addition, the resistance cords13are shown as elastic cords such as bungee cords, but could also be coil springs, fiberglass, carbon fiber or any other suitable material and configuration which allows for the storage of mechanical energy by stretching, bending, twisting or other physical deformation.

The system12ofFIG. 1has a frame14that supports an indexing mechanism16. Two rails18are shown, one on each side of the frame14. A plurality of resistance cords13is provided that are individually mounted to each of the slide blocks20. The resistance cords13are mounted at the lower end to a carriage21that is guided by the rails18. By locking any one or combination of individual slide blocks20to the frame14, when the carriage21is moved down, away from the supported slide blocks20, spring tension is generated in opposition to movement of the carriage as may be caused by a user. By securing more or fewer slide blocks20, and thereby cords13the resistance to the user can be varied. An effective resistance training machine varies the resistance to accommodate users of different physical abilities and different muscle groups of the same user vary in strength potential. Also, preferably, as a user progresses and becomes stronger as an adaptation to resistance training exercise, the resistance applied continues to increase to meet the user's increased potential.

With reference toFIG. 2, a more detailed view of the indexing mechanism16is shown. In this embodiment of the invention, a pair of guide wheels22is positioned on either side of, and adjacent to the drive wheel24. The drive wheel24is actuated by a knob (not shown) on the front side of the device12. The drive wheel24mechanically drives a belt26in a serpentine manner near the upper portion of the slide blocks20. Near the lower edge of the guide wheels22is a support plate28being rigidly mounted to the frame14of the device12. The support plate28is substantially flush with the lower edge of an undercut30(also shown inFIG. 7) in each of the slide blocks20. The belt26is positioned adjacent to the undercut30with the bottom run of the belt26supported at least in part on the support plate28. A portion of the continuous loop of the belt26includes links32that extend beyond the width of the belt26extending in the direction of the slide blocks20. Links32may be strategically positioned on the belt26, or the links32may form a portion of the loop such that the belt26and the links32are joined in series to complete the closed loop. When positioned on the lower run, the edges of the links32can be moved to be received by the undercut30in some or all of the slide blocks20. The links32that are received by the undercut30of any of the slide blocks20have the outer portion of the links32supported on the support plate28, the links providing a bridge to the support plate28. Those slide blocks20are therefore supported by the support plate28, which is mounted to the frame. This support system inhibits at least partially the downward movement of those individual slide blocks20when the carriage21is actuated down by the user. This support offers a reaction force so that tension is generated in the resistance cord13associated with that particular slide block20. By actuating the drive wheel24and causing the lower run of the links32to advance to the left in the view shown inFIG. 2, more slide blocks20and therefore more resistance cords13are engaged and the tension to the user is increased. By reversing the movement to the right, fewer slide blocks20are engaged and therefore the resistance to the user is reduced.

With reference toFIGS. 3 and 4, a front view of the apparatus is shown, with more detail inFIG. 4. In both views the front cover has been removed to better show the detail of these aspects of the invention. The front of the machine allows access to the user. The dial34is easily accessible by the user. A position indicator is shown in one embodiment as a series of indication marks36that correspond to the position indicator38, which is mechanically linked to the dial34. The indication marks36are one means of identification of the resistance provided by the device12as will be described in more detail below. In many embodiments these indication marks have been removed to better show other aspects of the invention. The position indicator38gives visual feedback to the user as to the resistance set by the mechanism16. The dial34is in mechanical communication with the drive wheel24(FIG. 2) which drives the belt26and attached links32. As such, a specific position of the dial34corresponds to a direct orientation of the links32relative to the slide blocks20, and therefore the number of slide blocks20which are engaged or free to move relative to the frame14, providing a specific resistance to the user.

With reference toFIG. 5, a detail of the indexing mechanism16is shown alone from the rest of the device12. The center section of the slide blocks20are broken out to better give a full view of the mechanism. The dial34articulates with and drives the belts26. A portion of the belt26includes a series of links32. These links32with the belt26complete a loop around the drive wheels24. In this embodiment there are two belt26and link32systems, one on each side of the slide blocks20. The links32are received by the undercut30in the slide blocks20only when the links32are supported on the support plate28. By supporting the slide blocks20on the front and rear there is no eccentric load in the blocks20when they are loaded. It has been determined by the applicants that support on a single side of the slide blocks20is functional and will be discussed relative to another embodiment.

In this view, the center slide block20′ is shown with a center slot35. This is one of many solutions to a potential interference issue of an axle40(shown inFIGS. 7-10) that may be used to connect the drive wheels24to the dial34. In other embodiments, a shortened center slide block20′ may be used or a space may be provided between the two slide blocks20positioned closest to the dial34, thus allowing the axle40to pass from the front to the rear of the mechanism16without interference with the slide blocks20. Still another method of synchronizing the front and rear belts26may be done without the axle40. In this embodiment, the adjacent guide wheels22on one or both ends of the mechanism16may be joined to their adjacent guide wheel22on the side of the mechanism16by a shaft37. The common movement of the adjacent guide wheels22causes the belts26to move together, thereby linking the movement of the belts26to one another. In this view a dial34is shown as the method of user interaction with the method of positioning the links32. It is understood that alternate forms can also be used in this or any other embodiment of the invention including an electric motor adapted to actuate the system remotely or by a switch mounted on the device12. In this embodiment the dial34would not be necessary.

More detail of the engagement of the links32to the slide blocks20and20′ is shown inFIG. 6and the section view inFIG. 7. The undercut30is clearly seen inFIG. 7in this embodiment and is provided on both sides of the slide block20and20′ as previously stated. This provides a more balanced distribution of load to the system by pulling on both sides concurrently as well as doubling the area of distribution of load shear so as to reduce the stress in the slide blocks20and20′ and the links32as compared to using one side only when a force is applied to pull the slide block20and20′ down. It is understood that this is not critical to the novelty of the invention and in some cases, as will be shown if further embodiments of the invention, a system with support on a single side will be used.

The positioning mechanism39is shown inFIG. 8with the center structure of the indexing mechanism16and the center slide blocks20broken out for clarity of the illustration. Also referring to this description is the detail view ofFIG. 9shown along the line9-9inFIG. 8. The belt26and links32have also been removed in these views. This illustrates one method of locating the links32in the proper position relative to each slide block20. Proper positioning of a link32so that it is fully engaged in the undercut30of a slide block20that is to be supported is helpful. If a link32is positioned only half way in the undercut30of a slide block20, the pressure on that slide block20at the undercut30will be twice as great as if the link32was fully engaged.

This potential for excessive forces on the slide blocks20was solved by providing a positioning mechanism39that is mounted to the knob34by way of the knob axle40. The axle40is securely mounted to the drive wheels24which drive the belt(s)26and therefore the links32. A sprocket41is also secured to the axle40. This sprocket41has a series of detents43along the peripheral edge. These detents43mate with the pin45secured to the lever arm47, which is pivotally mounted to the frame of the indexing mechanism16. The angular displacement or the sprocket41, and therefore the axle40, from one detent43to the adjacent detent43is equal to the linear displacement of the belt26, which is the distance of the spacing of one slide block20to the adjacent slide block20. A spring49acts as a bias to pull the lever arm47and pin45toward the sprocket41. The combination provides that as the knob34is turned by a user, it will move one “click” at a time in either direction to add or remove the links32one full slide block20at a time eliminating the potential for a link32to be only partially engaged with the undercut30of any slide block20.

The indexing mechanism16of the device12is shown in use in one embodiment inFIGS. 10-12.FIG. 10shows a carriage21with a plurality of resistance cords13mounted to the lower portion of the carriage21. A cable51supported by a pulley53(which would be rotatably mounted to the frame14) and the free end of the cable51would be adapted for direct or indirect communication with the user to actuate the cable51to exercise the muscles of the user. The upper portion of the cords13are each mounted to a slide block20. In this view as well asFIGS. 11 and 12, it is shown that the four slide blocks20on the right are supported by the support plate28, which is secured to the frame14, by way of the links32being positioned on top of the support plate28and received by the undercut30of those four slide blocks20. The rest of the slide blocks20not having links32in their respective undercut30are free to move down with the carriage21as the carriage21is actuated. The four cords13on the right are then stretched and thus provide a resistance to movement of the carriage21provided by tension in the cable51.

The slide blocks20that are not supported by a link32and are therefore free to move with the carriage21are supported on the carriage21. One method of support is shown inFIG. 13. The bottom portion of the slide blocks20rest on the top of the carriage21and therefore when not engaged by a link32, move up and down with the carriage21. This is only one method of supporting the slide blocks20. Related forms are shown in the prior art of reference. Various forms of support of the slide blocks20on the carriage21could be incorporated here. As the user allows the carriage21to move back up due to the tension of the engaged cords13, the slide blocks20supported by the carriage21will move back up to be positioned adjacent to the slide blocks20that are supported by the links32. In this and other views, some of the structure of the frame14has been removed to better show specific features of the invention. Here, one or more physical guides can be used to insure the slide blocks20move in a controlled and reasonably precise path.

It may be desirable to have the cords13slightly tensioned when in this semi-relaxed state (slide blocks20moving with the carriage21). This may serve several purposes. First, the slide blocks20are firmly held to the top (in this vertical movement orientation of the carriage21) of the carriage21when the slide blocks20are not engaged by the link32and providing resistance to movement of the carriage21. The second advantage is the cords13may offer a “preload” to allow the user immediate resistance when actuated. This helps eliminate the “lag” or “mushy” feeling at the beginning of the movement which is found with some devices. In some cases a cord13may also be permanently engaged with the carriage21to offer a bias in the direction of the links32. This is one way to move the carriage21to the starting position to enable engagement with the links32.

When the device12is relaxed, the carriage21will move back up to the starting position with all slide blocks20fully elevated. At that point the user can actuate the knob34and drive the links32to support more slide blocks20and increase the resistance to movement by way of the cable51or actuate the knob34in the opposite direction to remove the links32from the undercut30of one or more slide blocks20, thereby reducing the resistance to movement of the carriage21by way of the cable51.

An alternative embodiment is shown inFIGS. 14-17. This embodiment shows a system with many of the same components including a dial34and guide rails18. In this embodiment the resistance is also a plurality of resistance cords13. Again, the system could be adapted to apply to any number of types of resistance. One advantage to resistance cords13is the mass is negligible relative to the tension produced and therefore the physical orientation of the system is substantially irrelevant. In the embodiment as shown inFIGS. 14-17the resistance cords13are mounted horizontally. The carriage21is moved in the direction of the arrow44when tension is produced by the user. Any number of mechanisms can be used for the purpose, most probably as previously disclosed a pliable cable, cord or belt with a distal end adapted to interaction with the user is preferred. The carriage21moves linearly on the guide rails18by a slide, linear bearing or roller mechanism. This is not shown in this embodiment but it would be similar to that as previously disclosed. This also pertains to the support plate28, not shown inFIGS. 14-17and20-22. These figures illustrate different elements and most of the parts of the frame have been removed to better show these features. Preferably, the support plate28or its functional equivalent is present on the carriage21side of an index plate46or link32in all the embodiments of the invention. As is illustrated in this and other figures the index plate46has functionally equivalent features to the link32of the previously described embodiments of the invention.

The reaction force to enable resistance in the resistance cords13is provided by the index plate46and as noted a support plate28(not shown) secured to or as part of the frame14. As in the previous embodiment, the carriage21is displaced by the user, the variation in tension is determined by the number of resistance cords13in which the free end is secured to the frame to offer a resistive force. In this embodiment, the dial34drives a flexible member48such as a cable, belt or chain. The flexible member48is attached to each end of the index plate46as shown. Turning the dial34to the right moves the index plate46down, increasing the number of resistance cords13supported by the index plate46and turning to the left moves the index plate46up, reducing the number of cords13supported by the index plate46.

InFIG. 15, a detail of the index plate46and the relationship to the resistance cords13is shown. In this embodiment a finer resistance adjustment can be made in that the index plate46includes three slots. The left slot50and right slot52have a series of spaced openings54. When the index plate46is positioned such that the corresponding left resistance cord tab56passes through the opening54, that particular resistance cord does not generate any tension to the user. The left resistance cord58and right resistance cord60may be of lesser tension capability (lower spring constant) than the main center resistance cords13. For example, the left resistance cord58offers ten pounds of resistance to the user and the right resistance cord60may be designed to provide five pounds of resistance to the user and the main center resistance cords13may be designed to offer twenty pounds of resistance. In the position shown only the center tab62is supported by the edges of the center slot64, so the total resistance would be twenty pounds to the user.

InFIGS. 16 and 17the index plate46has been actuated (moved down) to a higher tension. As the index plate46indexes down, the center tab62(functional equivalent to the support flange) still maintains contact with the index plate46so that twenty pounds is maintained. In addition, a second center tab66has been added to add an additional twenty pounds of resistance. The fine adjustment is provided by the side tabs (56and68). As illustrated inFIG. 16as an example, the right tab68is engaged with the index plate46so that five pounds of resistance is added to the two twenty pound center tabs (62and66) to make the total resistance forty-five pounds. The next notch would drop the right tab68and add the left tab56. This adds ten pounds to the forty provided by the two center tabs to give a total of fifty-pounds of resistance. One more notch will add the right tab68with the left tab56and the two center tabs for a total of fifty-five pounds. The next step will drop the right tab68and the left tab56out and add a third center tab70to the center slot64. Three twenty-pound resistance cords sums to sixty pounds of resistance to the user. This illustrates how this system can provide five pound increments to the user with a base of a plurality of twenty-pound resistance cords13, one five-pound resistance cord60and one ten-pound resistance cord58. This process would increase with each step for as many main resistance cords as desired.

A variation to this embodiment could include a single slot64without the left slot50and right slot52. This single slot can include the larger resistance cords13as shown in the drawings or the center system of resistance cords13can alternate such that the higher resistance cord is followed by a lower resistance cord or any other combination and then a notched slot would preferably be used in that an alternate heavy and light cord can be picked up and dropped out of the resistance system as the index plate46is moved. In this way the increments can vary according to any design criteria desired. It is understood that any number of slots can be used in each embodiment and it is only a design variation. The general system will function in a like manner with greater or fewer increment settings.

Other variations are further illustrated inFIGS. 16 and 17. The index plate46can include a lip72as shown. This lip72or any other similar structure can be actuated directly by the user without the need of the knob34. The system of the index plate46is similar as with the dial34, only that the number of components of the system may be reduced by the possibility of actuating the index plate46directly by the user.

As previously noted, it may be desirable to have a belt26and link32type system with more than one belting system running in parallel to actuate different combinations of resistance cords13, thereby generating smaller increments in resistance. One example of such an indexing mechanism16′ is shown inFIGS. 18 and 19. In this view a vertical arrangement of the main cords13is attached to a carriage21as well as a low tension right cord60and a lower tension left cord58. One of the center cords13is broken to better show the lower tension right cord60. The modified support plate28′ acts as a support platform that is secured to the frame (not shown in this view) but is consistent in orientation and support of the rails18. The indexing mechanism16′ is mounted to the top of the support plate28′ by way of two shafts71. These shafts71would be journaled to the support plate28′ or the frame to allow rotational movement of the shafts71with their axes stationary with respect to the support plate28′.

The shafts71are mounted to two sprockets73on each end of the support plate28′. Each pair of sprockets73drive a custom conveyor chain75. Each custom conveyor chain75has an arrangement of chain ears77that extend laterally from the base links79of the chain75. The chain ears77are supported by the support plate28′ when on the lower run of the chain75loop. The chain ears77are positioned such that they provide selective interference with the left tab56, center tab62and right tab68which are each secured to the upper ends of the resistance cords58,13and60respectively. When a chain ear77is positioned between a tab (56,62or68) and the support plate28′ that associated resistance band is secured to the support plate28′. This indexing mechanism16′ is in this manner functionally equivalent to the sliding index plate46shown and described inFIGS. 14-17only with a segmented rolling system provided by the chain75as opposed to a flat index plate46that slides in a linear manner. The spacing and orientation of the chain ears77are such that they can be made to alternatively pick up and drop off selected resistance cords so as to provide a variety of incremental resistances. A break out area81of the conveyor chain75is shown inFIG. 19to better illustrate the second center tab66and as such, all other center tabs.

The indexing mechanism16′ as shown inFIGS. 18-19is an embodiment that allows for similar adjustment capabilities as that shown and described inFIGS. 14-17, only here in a rotary rather than sliding system. It is understood that a single custom conveyor chain75could also be used to support one or two rows of resistance cords13as well as multiple chains75to pick any number of rows of resistance cords13. The number of chains75and rows of cords13is not intended to be limited by the disclosure.

The dial34is shown here to be mounted to one of the shafts71and functions to drive the chain75relative to the support plate28′. This dial34could also be mounted with a dedicated drive system that directly drives the conveyor chain75. In some cases this would be desirable in that a single rotation of the dial34would be preferred to give a precise location of the conveyor chain75and therefore the specific combination of cords (58,60and13) supported. In this case the dial34would be geared with a secondary drive sprocket (not shown) that drives the conveyor chain(s)75directly such that one revolution or less of the dial34moves the conveyor chain75through all possible combinations regarding support of the resistance cords (58,60and13). In addition any one of a number of location systems known or disclosed herein can also be implemented to provide precise incremental advancement of the chain(s)75and therefore resistance combinations.

Another alternative to the system of index plate46′ location is shown inFIG. 20. In this embodiment the flexible member48and the dial34have been eliminated and the index plate46′ is actuated in a linear manner by engaging some structure on the index plate46′, such as the lip72. A linear positioning system74is added to show another method of locating the index plate46′ relative to the cords13to ensure a specific load is provided in the cable51for the user. In this embodiment the index plate46′ includes a locking pin76. There are many types of locking devices that could be adapted to work in this environment. A locking spring pin76as shown here has several advantages as will be discussed.

The locking pin76includes a cylinder78which houses a pin that includes a knob80mounted to one end. A compression spring is housed in the cylinder to bias the pin away from the knob80and toward the rail82. The far end of the pin is received by one of a plurality of holes84in the rail82. The cylinder78and knob80alone or together act as a handle, analogous to the lip72on the index plate46′ in that it can be grasped by the user to move the index plate46′ up or down. One advantage with such an assembly is the same hand can be used to grasp the knob80, pull the knob80and attached pin away from the rail82and move it up or down to the desired location, all with one hand. The location and number of holes84in the rail82may be varied and are shown here as an illustrative example. In addition, in this embodiment the lip72could be removed from the index plate46′ if desired.

In a manner similar to that shown and described relating toFIG. 20, an embodiment including a rotating location system is shown inFIG. 21. In this embodiment the index plate46″ would, as with the other examples, also be moveably mounted in some guide or track to enable precise and consistent movement of the index plate46″ relative to the cords13&60. A gear knob86is mounted to a pinion gear88which is in turn rotatably mounted to the frame14(not shown in this view). In doing so the axis of the pinion gear88is stationary with respect to the cords13and rails18. A gear rack90is mounted to or otherwise continuous with the index plate46″. By actuating the gear knob86the pinion gear88drives the gear rack90and attached index plate46″ up or down to increase or decrease the engagement of the cords13with the index plate46″, thereby changing the resistance in the cable51to the user. This system provides a fine adjustment in the movement of the index plate46″ relative to the cords13. One of any number of location mechanisms previously disclosed or otherwise known can be used in conjunction with this embodiment to ensure proper incremental movement of the index plate46″ and therefore engagement of the desired cords13&60.

In another embodiment of the invention, a sliding index plate46′″ is illustrated inFIG. 22. An advantage to the embodiments disclosed herein is the forces applied by any of the cord tabs62as previously shown on any of the index plates46are primarily sheer forces. As such, only a small amount of material is needed to support a great deal of force. With materials including spring steel, a semi-pliable index plate46′″ can be made that will change orientation to follow a specific contour and yet structurally support the cord tabs62of the desired cords13. An advantage is the overall package size can be reduced in that this index plate46′″ can adapt to the existing size and shape of the device12. An example of this is shown here.

A plate guide92is positioned adjacent to the cords13. The plate guide92may include a curved contour and a pair of plate guide rails94that receive the outside edges of the index plate46′″. In this embodiment the lip72′ is positioned at a first end96of the index plate46′″ to give the user a handle to move the index plate46′″ up and down in accordance with the arrow98. In this orientation of the index plate46′″ as the first end96moves up or down a second end98of the index plate46′″ moves back or forward as noted by the second arrow100. This movement is directed by the plate guide92, of which the shape and contour are infinitely variable to virtually any desired shape. The general function of the index plate46′″ is otherwise similar to that as previously disclosed.

Another embodiment of the invention is to use a disc shaped index plate46″″. This is illustrated inFIGS. 23 and 24. In this embodiment the cords13are positioned vertically and mounted to a lower plate102. This lower plate is the functional equivalent to the carriage21in previous embodiments. The lower plate102is able to move down away from an upper plate104when actuated by a user by any attachment means desired. The lower plate102is shown here to be guided by a linear shaft106that would articulate with a bearing in the center of the lower plate102. This is only one form of guiding the lower plate of which is infinitely variable and not intended to be limiting to the scope of the invention.

The cords13provide the resistance to downward movement of the lower plate102. Support of the cords13to the upper plate104is determined by the orientation of the index plate46″″ which is supported by the upper plate104. Thereby the upper plate104is the functional equivalent to the support plate28of previous embodiments, providing support for the index plate46″″. Though functionally equivalent to the process of selective engagement of the cords13to the index plate46in previous embodiments, this version allows the index plate46″″ to be rotated rather than displaced in a linear manner. As with the other embodiments of the invention, one or more slots can be used with any embodiment shown. Also, any of the positioning systems shown or known can be incorporated into any of the embodiments.

The upper portion of the cords13include a cap cord108that has an undercut30suitable for engagement with arc slot110while allowing the cap108to pass through the opening54′. The general function of this embodiment is otherwise similar to that as previously disclosed. The advantage is this arrangement may be desirable in some cases in necessitating a potentially smaller space requirement and thus potentially reducing shipping and storage costs.

In all embodiments of the invention disclosed thus far, the carriage21(and102) is actuated away from the support plate28(and104). The support plate28and index plate46are positioned stationary with respect to the frame14and the carriage21(and102) is then movable with respect to the frame12with a second end of the resistance elements13secured to the carriage21(and102). It is also possible to make the support plate28(and104) part of the carriage21and be therefore movable with respect to the frame14while the second end of the resistance elements13are fixed to the frame14. Preferably, the index plate46and support plate28(and104) move relative to the second end (cord end not releasably secured to the index plate46) of the resistance element13. The specific movement relative to the frame14may be performed in either manner.

The foregoing detailed description of the present invention is provided for purposes of illustration and it is not intended to be exhaustive or to limit the invention to the particular embodiments shown. The embodiments may provide different capabilities and benefits, depending on the configuration used to implement features of the invention.