Patent Abstract:
An exercising machine wherein a cable pull is resisted by spring deflection. The cable is connected to a lift arm that is pivotally fixed and carries a lift roller. The lift roller abuts a pivotally mounted bar and urges pivotal movement of the bar opposed by a spring member. The connection of the cable to the pivotal lift arm, the position of the lift roller relative to the lift arm pivot, the engagement of the roller with the pivotal bar and the engagement of the spring member with the pivotal bar all involving lever advantages that can be manipulated to achieve varying shapes of resistance of the cable pull as felt by the user.

Full Description:
FIELD OF THE INVENTION 
     This invention relates to exercise machines that simulate weight lifting wherein resistance is provided by spring action and more particularly it relates to controlling the resistance. 
     BACKGROUND OF THE INVENTION 
     Exercising one&#39;s muscles has progressed from free weights to machines where creative assembly of weights and cables enables a person to exercise most if not all of the muscles of his/her body. Athletic clubs offer as many as 20 or more different types of machines whereby a person can progress from machine to machine and direct the exercise to different muscles of different body parts. A person can readily vary the effected weight resistance by moving a pin that adds or subtracts the number of weights that produce the resistance. 
     Whereas athletic clubs are desirable for a substantial segment of the population, there is a demand for home exercising machines as well. It is not generally feasible for individuals to equip their home with these same machines. Such are expensive to purchase, expensive to ship due to the bulk and weight, and substantial home space has to be dedicated to machine use only. 
     A large dedicated space and numerous machines are quite acceptable for an athletic club as such accommodate numerous users of the machines, the users simply staggering their time of use and sequentially cycling through the different machines. Home use on the other hand is typically a single user and space and cost are important considerations. Accordingly, home use exercising machines have been developed whereby a single machine having a creative arrangement of cables and pulleys with relatively simple adjustments thereof can provide variable resistance applicable to a wide range of user muscles. The weights of the athletic club exercising machines are replaced, e.g., with spring members that provide the desired resistance for exercise but which have only a fraction of the true weight of “weights” used for the athletic club machines. Shipping costs are dramatically reduced and the machines can be more readily moved by the home owner/user, e.g., to storage or from room to room. A guest room may be convertible as desired for guest use or for exercise use as but one example. Such a machine is hereafter sometimes referred to as a universal machine. 
     One problem with the use of spring members to replace the “weights” is that a spring member varies in its resistance as the spring member is deflected. A pull cable acting to deflect the spring (deflect here encompassing compression, tension, bending, etc.) may require an increasing force, e.g., a force of 5-10 pounds over the first several inches of deflection, 10-15 pounds of force over the next several inches of deflection, etc. To this extent, the spring members do not equate to a free weight which requires a constant pull force over whatever length of pull is required for the particular exercise. It is accordingly an objective of the present invention to provide a universal exercise machine that utilizes a spring force versus “weights” while providing a steady resistance to a cable pull against the spring action to simulate a true “weight.” Thus, the resistance that the user experiences remains constant throughout the entire range of deflection, even though the actual resistance provided by the spring member increases as greater deflection occurs. Alternatively the resistance may be “shaped,” i.e., to generate an increasing resistance or decreasing resistance or combination of increasing and decreasing resistance as may be desired for a particular exercise. “Shaped” resistances refer to dynamically changing resistances that are “felt” by the user during an exercise. Each “shaped” resistance can be thought of as a resistance curve that shows the range of movement caused by the user and the corresponding “felt” amount of resistance. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In the preferred embodiment, the spring action is provided by an elongate spring member. The spring member is preferably a cylinder of elastomer having the property of being resistively and resiliently compressible. The spring member is not limited to a cylinder of elastomer, and it will be understood by those skilled in the art that other types of compressible cylinders may be used, such as a conventional spring, gas spring, etc. It may be confined in a tube that permits collapse/compression and prevents bending to thereby permit axial compression only of the elastomer cylinder. It is desirable that the range of forced differential, i.e., the force required to deflect the cylinder at the start of the cable pull versus the force of cable pull at the end of the cable pull be minimized and this is accomplished by precompressing the cylinder. Thus, with the tube at full extension, the cylinder in the tube is held to the precompression load. Alternatively, the cylinder may be skewered on a rod and sandwiched between washers. Precompression can be accomplished by providing a stop at one end and a nut threaded on the other end, the nut turned to shorten the distance between the washers to thereby compress the cylinder. 
     The resistance of the cylinder to further compression nevertheless still varies (gets stronger) and an arrangement is provided to counter this variation. A cable extends from the user&#39;s lifting bar or rings or foot pedal or whatever that is to be moved by the user to exercise a particular set of muscles. The cable is directed through pulleys as necessary to direct the cable from an overhead position to a lift arm. The lift arm is secured at one end to a rotatable pin or axle and the other end is connected to the cable. Pulling of the cable upwardly achieves pivoting of the lift arm about the axle axis as well as rotation of the axle. Also affixed to the axle is one end of an abbreviated (relatively shorter) pivot arm having a lift roller at its distal end. The lift roller engages the under side of a formed pivotal bar spaced from the point of pivoting. The elongate collapsible tube containing the elastomer cylinder is pivotally attached at one end at a position above the pivotal bar with the opposite end extending down to and engaging the pivotal bar also spaced from the point of pivoting. 
     In order to pull the cable, the lift arm has to be raised producing pivoting of the axle. This produces raising of the lift roller which acts against the formed pivotal bar to pivot the formed bar about its axis which is only accomplished by compressing the tube and cylinder. 
     The arrangement described provides a number of variables, the most important perhaps being the arc of movement by the abbreviated pivot arm. For a given distance of cable pull, the abbreviated pivot arm is pivoted through an angular arc. For explanation purposes, assume that the lift roller and pivot arm at the start of the pull extend to a 9 o&#39;clock position and is pivoted to a 12 o&#39;clock position. The resistive force of the formed bar is assumed (for explanation purposes) to produce an effective force directed vertically downward. The total vertical distance that the lift roller is assumed to travel is three inches (which is also the distance the roller moves horizontally). 
     It will be further assumed that the total distance of cable pull to affect the 90 degree pivotal movement of the pivot arm is 42 inches, i.e., the cable pull is 14 inches for each 30 degrees of rotation of the pivot arm. During the first 14 inches of cable pull, the pivot arm is rotated 30 degrees, i.e., from the 9 o&#39;clock position to the 10 o&#39;clock position. Whereas only one-third of the rotation has been completed, essentially half of the vertical distance has been completed, i.e., the formed bar has been raised about one and one-half inches with one-third the pull of the cable. The remaining one and one-half inches of vertical lift is accomplished through 60 degrees rotation of the pivot arm and 28 inches of pull of the cable. Thus, the load experienced by the user tends to get smaller (due to the changing angular direction of movement of the lift roller relative to the formed bar). As previously explained, the necessary force to compress the elastomer cylinder increases throughout compression and these variables offset one another. 
     The above is a somewhat simplified explanation but once the concept is appreciated, it will be understood that manipulation of such factors as lever length and point of engagement of the lift roller with the formed bar and the shape of the bar itself provides the opportunity to control the variables and “shape” the applied resistance to a particular exercise selected by the user. The invention will be more fully understood and appreciated upon reference to the following detailed description of the preferred embodiment and the accompanying drawings. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a universal exercise machine in accordance with the present invention; 
     FIGS. 2-4 illustrate examples for adjusting the resistance provided for the universal exercise machine of FIG. 1; 
     FIG. 5 is a perspective view of the working components of the machine of FIG. 1; 
     FIG. 6 is a more detailed and enlarged side view illustration of the working components of FIG. 5; 
     FIG. 7 is a section view as indicated by view lines  7 — 7  of FIG. 6; 
     FIG. 8 is a schematic illustration of the variable effect of the pivot arm and lift roller embodied in the illustrations of FIGS. 5-7; 
     FIG. 9 is a side view of certain of the working components of an alternate embodiment of the invention; 
     FIGS. 10-18 illustrate the working components of FIG. 9 in greater detail; and 
     FIGS. 19-23 illustrate further embodiments of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is a side view of a universal exercise machine in accordance with the present invention. The frame  10  of the machine is represented by front and rear struts  12 ,  14 , respectively, and upper and lower cross braces  16 ,  18 , respectively. What is shown is one side of the frame, the opposite side (the near side) is removed to illustrate the mechanism providing the lifting resistance supported by the frame  10  between the two sides. 
     A lifting cable  20  from the lifting paraphernalia (pull rings, bars, foot pads and the like) extends from guide  22  over upper pulleys  24  down to a lower pulley  26  and back up to drum  28  where the end of cable  20  is secured to the periphery of the drum and is wound onto and off of the drum as the lift cable is moved up and down through the guide  22 . The details of the cable extension to the various paraphernalia is not shown. As those skilled in the art will appreciate, different arrangements of pulleys and guides are provided to direct the cable as necessary to achieve the desired resistive force, e.g., for overhead lifting, leg pushes and the number of other kinds of exercise routines common to such universal equipment. 
     The invention is more specifically (but not exclusively) applied to cable extension  31  that extends from an inner periphery of the drum  28 , through pulley  30  and then connected to the distal end of lift arm  32 . Lift arm  32  is fixedly secured to axle  34  and raising and lowering of the distal end of the lift arm  32  produces rotation of the axle  34 . With reference also to FIGS. 5-7, an abbreviated pivot arm  36  is also fixed to the axle  34  and carries at its distal end a lift roller  38 . Lift roller  38  engages a distal end of an elongate formed bar  40  which is pivotally connected to the frame at pivot  42 . (See FIG. 1) 
     Overlying the elongate formed bar  40  is a spring member  44  shown best in FIG.  6 . As shown, the spring member  44  includes an elastomer cylinder  46  contained and constrained in tube  48 . In one version, the tube  48  is provided in sections that overlap at joints  50  and has upper and lower end caps  52 . As illustrated in FIGS. 1 and 6, the tube sections are fully extended. Joints  50  are formed to allow inward telescoping of the tube sections but prevent separation of the sections. The end caps  52  are secured to the top and bottom tube sections and thus capture the elastomer inside the tube at the fully extended position while allowing inwardly directed movement to further compress the elastomer cylinder  46 . Tube  48  may also be a non-collapsible tube with the cylinder being compressed within the tube. For example, the cylinder may be skewered and contained between end washers as indicated in the previous Background of the Invention. 
     With reference to the version of FIG. 6, the elastomer cylinder is loaded into the tube  48  under compression but as shown in FIG. 6, tube  48  is fully extended and the resilient force of the cylinder is fully contained by the tube ends  52 . The cylinder  46  thus provides no force against the formed bar  40  (as shown in the solid line position of FIG. 6) which is in a relaxed position coinciding with the maximum reach of the tube  48 . 
     In the relaxed position of FIG. 6 (solid lines) with the tube in its fully extended position and restraining the elastomer cylinder, the spring member can be pivoted to any position along the length of the bar  40 , the upper side  54  of the bar  40  being curved to match the pivotal movement of the distal end of spring member  44  which is equipped with a roller  56 . Movement of the end of spring member  44  adjusts the resistance to pivoting of bar  40 . Accordingly, the spring member is shifted along the length of the bar  40  as desired, an example being illustrated in phantom line in FIG.  6  and in solid line in FIG.  1 . At whatever position of the spring member  44  is desired, i.e., the resistance desired for a particular exercise, the position of the spring member  44  is locked in place by a lock device (latch)  60  provided on the distal end of the spring member  44  which engages a selected one of the positioning holes  58 . 
     Refer to FIG.  6  and observe the two extreme positions of lift arm  32 . Because the abbreviated pivot arm  36  and roller  38  are fixed to lift arm  32  (via axle  34 ), pivot arm  36  travels through the same pivoted angle but the arc of movement (the distance of travel) of roller  38  is a fraction of the arc of movement of the distal end of arm  32  (at connection  35 ). The distance that the cable  31  moves during such pivoting (which closely corresponds to the arc of movement of the distal end of lift arm  32 ) is a pre-established desired distance of movement by the lifting paraphernalia, e.g., a distance of about 42 inches as compared to a much shorter distance of movement by roller  38 , e.g., about 3 inches. This movement of the roller  38  forces upward pivoting of bar  40 . Bar  40  has no vertical movement at axis  42  and increasing vertical movement along the length of the bar away from the axis  42 . Thus, as the spring member  44  is positioned outwardly of pivot  42  (e.g., the phantom line position in FIG.  6 ), the same pivotal movement of lifting arm  32  imposes increased compression of the spring member  44 . This difference can be observed by noting the phantom line (raised) position of bar  40  and particularly the upper surface  54  of bar  40  (the dash line position in FIG.  6 ). With the spring member  44  positioned near the axis  42 , very little compression is imposed on the spring member. When shifted, e.g., to the phantom line position, a much greater compression is imposed on spring member  44 . 
     It will also be appreciated from FIG. 6 that arm  36  and roller  38  move through an arc of about 90 degrees as dictated by pivoting of lift arm  32 . It will be observed that movement of the roller and arm through the arc changes the reach of arm  36  from a position somewhat parallel to the bar  40  (solid line position) to a position near perpendicular to bar  40  (phantom line position). Refer to FIG. 8 which illustrates the effect of such movement. The radial line a, b represents the arm and roller  36 ,  38  in the parallel position (the solid line position of FIG. 6) and radial line a, b′ represents the arm and roller  36 ,  38  in the perpendicular position (the phantom line position of FIG.  6 ). The remaining in between radial lines represent the graduated movement of the arm between position a,b and a,b′. The horizontal grid lines illustrate vertical distance, i.e., the upward movement of bar  40  and spring member  44 . Note that half the lifting distance, i.e., the one and one-half inch position (reference h) is reached during the first 30 degrees of pivoting and the remaining one and one-half inches is reached during the remaining 60 degrees of pivoting of arm  36 . 
     Accordingly, the required pull force of the cable  31  decreases as a result of the roller moving through the arc, i.e., position b to position b′. It is also to be noted that the point of contact with the bar  40  moves as represented by the vertical lines of the grid in FIG.  8 . As the roller moves from b to b′, it moves a lateral distance of three inches. This three inch movement away from pivot  42  increases the lever advantage of the roller  38  relative to the selected fixed position of spring member  44 . It will thus be understood that the increasing resistance of the spring member  44  is offset by (a) the changing direction of movement of the roller  38  as it moves through the arc (ab to ab′) the changing point of contact of the roller on the bar which increases the lever arm advantage. 
     The above explains the relationship of three variables, i.e., the spring member  44  having increased resistance while being compressed, the roller  38  moving in an arc and thus in an ever changing direction relative to the direction of applied resistance, and the roller shifting outward along the bar  40  to increase the lever arm advantage. These variables can be manipulated to achieve a desired resistive force felt by the user. 
     Refer to FIG.  2  and note that throughout the lifting action (from solid line to dash line positions), roller  38  moves along segment  62  of bottom edge  55  of bar  40  to lift the bar  40  from position a to position b. During this movement and as a result of such raising of bar  40 , roller  56  of spring member  44  is raised distance d (the solid line position being about two-thirds the distance between pivot  42  and the distal end of bar  40 ) thus compressing the cylinder  46  by distance d. Now refer to FIG.  3  and note the reconfiguration of segment  62 . Roller  38  is permitted to pivot through the same arc as in FIG. 2 but without raising the bar  40  and without compressing the spring member  44 . The above comparison (FIGS. 2 and 3) illustrates a further variable which is the configuration of segment  62 . It is particularly important because, as will be illustrated, it permits controlled manipulation of the previously described variables. Note FIG. 4 which schematically simulates roller  38  moving along a differently shaped segment  62  where the roller travels to a mid-point position (indicated by reference m) where full upward movement of bar  40  is attained and as roller  38  continues from mid-position to full pivoting (indicated by letter f), the bar  40  is lowered. 
     These FIGS. 2-4 are not intended to illustrate a working embodiment but rather are intended to explain the concept of how the applied force that is “felt” by the user can be manipulated. Whereas segment  62  of bar  40  can be configured so that throughout the cable pull the resistance felt by the user is constant to simulate the lifting of a true “weight,” it further provides the opportunity to vary the “shape” of the resistance that is “felt” by the user. 
     Reference is now made to FIGS. 9-17. FIG. 16 illustrates a bar  140  (corresponding to bar  40  in FIG. 6) wherein the distal end  142  of bar  140  is cut out and provided with bolt holes  144 . A carriage  146  carries three different cam segments  162 . Due to bolts  148  being larger than the width of bar  140 , carriage  146  can be shifted laterally relative to bar  140 . 
     As illustrated in FIG. 17, the carriage  146  is centrally mounted relative to bar  140  and the center segment  162  engages roller  38 . The carriage is prevented from undesired lateral movement due to the downward pressure exerted by the spring member  44  on bar  140  which urges the selected cam surface into groove  150  in roller  38 . (See FIG. 9) Whereas bar  140  and roller  38  are laterally fixed, the shifting of carriage  146  is enabled by first moving spring member  44  back toward pivot  42 , i.e., against stop  152 , which permits the user to pivotally lift bar  140  off roller  38  and simply slide carriage  146  to the desired position. FIGS. 9 and 15 illustrate carriage  146  moved to one of the side positions with cam surface  164   c  engaging groove  150 . 
     Carriage  146  and its cam surfaces  164   a ,  164   b  and  164   c  are further illustrated in FIGS. 10-14. Cam surface  164   a  is configured to provide substantially constant resistance,  164   b  provides increasing resistance and  164   c  provides decreasing and then increasing resistance. These are but a few examples of what may be provided. 
     This invention is very attractive because of the various “shaped” resistances from which a user can select, and also because this selection is simply accomplished by the user making a minor adjustment, without having to modify the machine. As briefly explained, if the user decides he wants to simulate a constant lift resistance as provided by cam surface  164   a , he simply moves the spring member  44  all the way back to engage stop  152  and then lifts bar  140  off roller  38 . This allows free sliding of the carriage  146  and he simply slides the desired cam surface into alignment with roller  38  and lowers the bar  140 . Moving spring member  44  outwardly from stop  152  assures the continued engagement of the selected cam surface with roller  38 . 
     Instead of sliding a shift carriage to select the desired resistance “shape,” replaceable single blades could be used to make the appropriate selection. The replaceable blades can engage the desired cam surface ( 164   a,    164   b  or  164   c ) to lift roller  38 , each cam surface representing a different resistance “shape” that the user experiences. Another substitute for the shift carriage is a rotary lock mechanism that can be rotated to different positions to engage the selected cam surface to lift roller  38 . 
     A further option that can be made available to the user is a replacement of pivot arm  36 . Such is not illustrated but is explained as follows: By providing a longer or shorter arm  36 , the resistance felt by the user correspondingly increases or decreases. It is furthermore contemplated that a shift carriage somewhat on the order of the shift carriage  146  can be provided to enable rapid interchange of such pivot arms  36 . 
     Yet another option that could be employed to obtain different “shaped” resistances is to allow the user to alter the point of pivot of lift arm  32 . Any movement of said pivot arm would have a corresponding change on the “shape” of the resistance. However, this option would require a moderately more complex adjustment because axle  34  would have to be separated from lift arm  32  before the adjustment could be made. 
     Whereas the above embodiments involve the use of cable and pulley connections, i.e., cable  31  and pulley  30 , it is contemplated that the connections can be provided by other means, e.g., gears. An example is illustrated in FIGS. 19-22. 
     Reference is now made to FIG. 19 which illustrates a first alternate embodiment. Lever arm  232  is mounted at axle  234 . The distal end of arm  232  is extended forward and fitted, e.g., with lifting grips  235  and a user U raises and lowers the arm end as indicated by arrows  237 . A pivot arm  236  is fitted to the same axle  234  (in a manner similar to the previous embodiment) and pivotal movement of lifting arm  232  generates pivoting of pivot arm  236  whereby roller  238  at the distal end of arm  236  engages and raises bar  240 . Raising bar  240  (around pivot  234 ) produces compression of spring member  244 . Spring member  244  is adjustable along bar  240  in the manner explained for the previous embodiments. 
     FIG. 20 shows a modification of the embodiment of FIG.  19 . In FIG. 20, the lifting arm  332  is pivotally secured to a separate pivot  333  which carries gear  335 . A larger gear  339  is secured to axle  334 . Gear teeth of gear  339  are engaged with gear teeth of gear  335  and pivotal movement of lifting arm  332  forces rotation of gear  339  and axle  334  but reduced by the gear reduction relationship of gears  335  and  339 . Pivot arm  336  is secured to axle  334  and roller  338  engages bar  340  to force pivoting of bar  340  around pivot  342 . Spring member  344  is accordingly compressed (corresponding to the pivot of roller  338 ) as in the manner of the prior embodiment. It will furthermore be appreciated that lift arm  332  may be directly manipulated by a user as in FIG. 19 or it may be connected to cables as in FIG.  6 . 
     FIG. 21 is a further modification of the embodiment of FIG.  20 . The lift arm  332  of FIG. 20 is replaced with pulley  350  mounted to pivot  333  and gear  335  is secured to pulley and/or pivot  333 . As in FIG. 20 the teeth of gear  335  force rotation of gear  339  and pivot arm  336  to raise and lower bar  340 . The pulley  350  is connected to a cable, e.g., cable  31 . (See also FIG.  6 ). 
     The above alternate embodiments and modifications are but examples of the many changes that can be made to the structure without departing from the intended scope of the invention, the primary objective being the control of transmitted resistance from a spring (having, e.g., an increasing resistive force) to the user U of an exercise machine. Accordingly, the invention is not to be limited to the illustrated embodiments but instead is intended to apply to a broadly interpreted scope of the claims as appended hereto.

Technology Classification (CPC): 0