Patent Publication Number: US-7909745-B2

Title: Adjustable resistance exercise device

Description:
TECHNICAL FIELD 
     The present invention relates to exercise devices and more particularly, to adjustable resistance exercise devices. 
     BACKGROUND INFORMATION 
     Physical exercise is widely recognized as an important component of maintaining physical fitness and overall health. One type of physical exercise, often referred to as resistance training, uses the resistance to muscular contraction to build the strength, anaerobic endurance and size of skeletal muscles. Various types of exercise devices have been developed to provide such resistance for use in resistance training. 
     According to one type of resistance exercise device, a user grabs a handle connected to a cable and an opposing resistance force is applied to the cable to resist the user pulling the cable. Such resistance exercise devices often allow the user to adjust the opposing resistance force that is applied against the cable. In such devices, the resistance force is often the same as the retraction force used to cause the cable to retract into the exercise device. Thus, changing the resistance force also results in a corresponding change in the retraction force used to retract the cable. The higher retraction forces resulting from higher resistance forces may cause an undesirable jerking action when using the exercise device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages will be better understood by reading the following detailed description, taken together with the drawings wherein: 
         FIG. 1  is a perspective view of an adjustable resistance exercise device, consistent with an embodiment of the present disclosure. 
         FIGS. 2A and 2B  are side views of the adjustable resistance exercise device shown in  FIG. 1  with the handles in seated and partially retracted positions, respectively. 
         FIG. 3  is a top cross-sectional view of the adjustable resistance exercise device taken along line  3 - 3  in  FIG. 2A . 
         FIG. 4  is a side cross-sectional view of the adjustable resistance exercise device taken along line  4 - 4  in  FIG. 2B . 
         FIG. 5  is an exploded view of the adjustable resistance exercise device shown in  FIG. 1 . 
         FIG. 6  is an exploded view of one embodiment of the adjustable resistance and retraction mechanism used to provide independent resistance forces and retraction forces on the cables in the adjustable resistance exercise device. 
         FIG. 7  is a cross-sectional perspective view of a resistance wheel selectively engaged with a cable receiving spool using a locking cam gear mechanism, consistent with an embodiment. 
         FIG. 8  is an exploded cross-sectional perspective view of the locking cam gear mechanism shown in  FIG. 7 . 
         FIG. 9  is a top view of the locking cam gear mechanism shown in  FIGS. 7 and 8 . 
         FIG. 10  is an exploded perspective view of another embodiment of the adjustable resistance exercise device. 
         FIG. 11  is a cross-sectional view of the adjustable resistance exercise device shown in  FIG. 10 . 
         FIG. 12  is an exploded view of another embodiment of an adjustable resistance and retraction mechanism. 
         FIG. 13  is a perspective view of the adjustable resistance and retraction mechanism shown in  FIG. 12 . 
         FIG. 14  is an exploded view of an adjustment mechanism in the adjustable resistance and retraction mechanism shown in  FIG. 13 . 
         FIG. 15  is a bottom view of the adjustment mechanism in the adjustable resistance and retraction mechanism shown in  FIG. 13 . 
         FIG. 16  is a cross-sectional view of an embodiment of a handle that may be used in an adjustable resistance exercise device. 
         FIG. 17  is a perspective view of the handle shown in  FIG. 16 . 
     
    
    
     DETAILED DESCRIPTION 
     In general, a resistance exercise device, consistent with the embodiments disclosed herein, enables resistance training by using one or more retractable cables that provide resistance to the user when the user pulls on the cable(s). The resistance exercise device provides a retraction force to retract the cable(s), which is independent of a resistance force applied to the cable(s). The resistance exercise device may thus allow adjustment of the resistance force without affecting the retraction force. In the exemplary embodiments described and shown, the resistance exercise device includes a portable exercise platform with two independently functioning cables; however, the concept of providing a retraction force independent of a resistance force may be used in other types of resistance exercise devices. 
     Referring to  FIG. 1 , an embodiment of an adjustable resistance exercise device  100  generally includes a platform  110  and handles  122 ,  124  coupled to cables  132 ,  134  that extend from and retract into the platform  110 . The platform  110  may generally include a housing  111  enclosing a resistance and retraction mechanism (not shown) for providing the resistance and retraction forces to the cables  132 ,  134 , as will be described in greater detail below. The platform  110  may also include handle engaging regions  112 ,  114  that receive the handles  122 ,  124  and a surface  116 , such as a flat surface, that receives a part of the user&#39;s body, such as the user&#39;s feet, to stabilize the platform  110  as the user grips the handles  122 ,  124  and pulls the cables  132 ,  134  from the platform  110 . The surface  116  may include a rubber mat and the bottom of the housing  111  may include one or more rubber feet (not shown). 
     Although the illustrated embodiment has a platform  110  and handles  122 ,  124  of a particular shape, various other shapes and configurations may be used. In other embodiments, for example, the platform  110  may be shaped or designed to receive other parts of the user&#39;s body (e.g., the knees, back, buttocks) and/or the handles  122 ,  124  may be shaped to be engaged by other parts of the user&#39;s body (e.g., the feet). Although the platform  110  is shown as a portable platform, the platform may be integrated in an exercise device that is fixed or the cables  132 ,  134  may extend from an exercise device without a platform. An exercise device implementing the concepts described herein may also include only one cable and handle or more than two cables and handles. 
       FIGS. 2A and 2B  illustrate a handle  124  in a retracted position and partially extended position, respectively. In the retracted position ( FIG. 2A ), the handle  124  engages the handle engaging region  114 . In an embodiment, for example, the handle  124  may be seated in the handle engaging region  114 . In an extended position ( FIG. 2B ), the handle  124  is removed from the handle engaging region  114  and a portion of the cable  134  extends from the platform  110 . When the handle  124  is moved from the retracted position to an extended position in the direction of arrow  102 , a resistance force F RS  is applied to the cable  134  to resist muscular contraction of the user pulling the cable  134  via the handle  124 . When the handle  124  is allowed to move to the retracted position in the direction of arrow  104 , a retraction force F RT  is applied to the cable  134  to cause retraction of the cable  134  into the platform  110 . As will be described in greater detail below, the retraction force F RT  is applied independently of the resistance force F RS  in that the resistance force F RS  is not applied when the cable  134  is retracted. 
     Referring to  FIGS. 3-5 , embodiments of a resistance and retraction mechanism that may be used inside of the housing  111  of the platform  110  are described in greater detail. The illustrated embodiment of the exercise device  100  generally includes a support frame  140  and cable receiving spools  142 ,  144  rotatably coupled to the support frame  140  and coupled to the respective cables  132 ,  134  (only cable  134  is shown). The cable receiving spools  142 ,  144  each rotate independently in a winding direction (as indicated by arrow  106 ) when the respective cable is being retracted and in an unwinding direction (as indicated by arrow  108 ) when the respective cable is being extended. Pulleys  143 ,  145  may also be rotatably mounted to the support frame  140  to receive and guide the respective cables  132 ,  134  to the respective cable receiving spools  142 ,  144 . The pulleys  143 ,  145  may each have an axis of rotation that is generally orthogonal to an axis of rotation of the respective cable receiving spools  142 ,  144  such that the spools  142 ,  144  can lie flat within the housing  111  of the platform  110  with the cables  132 ,  134  extending generally orthogonally from the platform  110 . 
     The housing  111  of the platform  110  may include first and second housing portions  111   a ,  111   b . One of the housing portions  111   a  (e.g., an upper housing portion) may include the surface  116  and the handle engaging regions  112 ,  114 . One of the housing portions  111   b  (e.g., a lower housing portion) may be designed to receive and secure the frame  140 . One or both of the housing portions  111   a ,  111   b  may include reinforcing structures  113 , such as walls, that reinforce the housing  111  to withstand the forces applied to the platform  110  when using the exercise device  100 . Although the frame  140  is shown separately from the housing portions  111   a ,  111   b,  the frame  140  may be integrated with or one-piece with the either of the housing portions  111   a,    111   b.    
     The exercise device  100  may include a resistance and retraction mechanism  150  that is operably coupled to the cable receiving spools  142 ,  144  to apply the resistance forces and to apply the retraction forces independent of the resistance forces. In general, the resistance and retraction mechanism  150  applies the resistance force to resist rotation of the cable receiving spools  142 ,  144  in the unwinding direction. The resistance force is then transferred to the respective cables  132 ,  134  to resist extension of the cables  132 ,  134  toward the extended position when the respective cable receiving spools are rotating in the unwinding direction. The resistance and retraction mechanism  150  applies the retraction force to cause the cable receiving spools  142 ,  144  to rotate in the winding direction. The retraction force is then transferred to the respective cables  132 ,  134  to retract the cables toward the retracted position when the respective cable receiving spools are rotating in the winding direction. Thus, the exemplary embodiment of the resistance and retraction mechanism  150  applies the resistance forces only when the respective cable receiving spools  142 ,  144  are rotating in the unwinding direction. The resistance and retraction mechanism  150  may provide an adjustable resistance force, as described in greater detail below, such that the resistance force may be changed without changing the retraction force. 
     As shown in greater detail in  FIGS. 5 and 6 , an embodiment of the resistance and retraction mechanism  150  may include resistance wheels  152 ,  154  rotatably coupled to the support frame  140  and one or more rotation resistance members  156  that engage the resistance wheels  152 ,  154  to resist rotation of the resistance wheels  152 ,  154 . The resistance wheels  152 ,  154  may be selectively engaged with the respective cable receiving spools  142 ,  144  such that the cable receiving spools  142 ,  144  cause the respective resistance wheels  152 ,  154  to rotate when the respective cable receiving spools  142 ,  144  rotate in the unwinding direction (i.e., engaged) and the respective cable receiving spools  142 ,  144  rotate independently in the winding direction (i.e., disengaged). Thus, resistance forces are applied by the resistance wheels  152 ,  154  only when the cable receiving spools  142 ,  144  are rotating in the unwinding direction, as will be described in greater detail below. 
     In the illustrated embodiment, the rotation resistance member  156  is a resistance belt  157  wrapped around both resistance wheels  152 ,  154  and engaging at least a portion of an annular surface of the resistance wheels  152 ,  154 . In this embodiment, the resistance force is the friction force that results from rotating the resistance wheels  152 ,  154  against the resistance belt  157 . Guides  153 ,  155  may be mounted to the frame  140  and may guide the rotation resistance belt  157  around a desired portion of the resistance wheels  152 ,  154 . The amount of surface area of the resistance belt  157  in contact with the annular surface of the resistance wheels  152 ,  154  (and thus the friction force) depends on the location of the guides  153 ,  157  relative to the resistance wheels  152 ,  154 . The amount of surface area of the resistance belt  157  in contact with the resistance wheels  152 ,  154  also affects the adjustability of the resistance force by changing the tension in the resistance belt  157 , as described below. As shown in  FIG. 3 , the guides  153 ,  155  are located such that the resistance belt  157  contacts between about ½ and ¾ of the circumference of the resistance wheels  152 ,  154 . In one embodiment, the resistance mechanism may be capable of providing a total of 140 lbs. of resistance force (e.g., 70 lbs. on each side). 
     One example of a resistance mechanism that uses a belt around a wheel is described in greater detail in U.S. Pat. No. 5,643,153, which is incorporated herein by reference. The rotation resistance belt  157  may be made of woven nylon or another suitable material that provides a similar coefficient of friction and that is sufficiently durable when subjected to the friction. The surface area of the resistance belt  157  in contact with the resistance wheels  152 ,  154  also depends on the width of the resistance belt  157 . In one embodiment, the resistance belt  157  may have a width in a range of about ½ inches to 3 inches. The rotation resistance member(s)  156  may also include separate resistance belts wrapped around each of the resistance wheels  152 ,  154  or may include other friction generating members that contact the resistance wheels  152 ,  154  to cause a friction force when the resistance wheels are rotated. 
     The resistance and retraction mechanism  150  may further include a resistance force adjustment mechanism  160  that adjusts the resistance force, for example, by adjusting the friction force generated by the resistance wheels  152 ,  154  rotating against the resistance member(s)  156 . According to the exemplary embodiment, the resistance force adjustment mechanism  160  includes a threaded adjustment rod  162  threadably engaged with a sliding block  164 , or similar structure, coupled to the resistance belt  157 . Turning the threaded adjustment rod  162  (e.g., using an adjustment knob  168 ) causes the block  164  to move and changes the tension in the resistance belt  157 , which changes the force applied by the resistance belt  157  against the resistance wheels  152 ,  154  and the resulting friction force. According to one embodiment of the adjustment mechanism  160 , a movement of the threaded adjustment rod  162  of about 1 inch allows an adjustment from 5 lbs. to 70 lbs. of resistance force applied by each of the resistance wheels  152 ,  154 . Other resistance force adjusting mechanisms capable of increasing or decreasing the friction force may also be used. 
     The exemplary embodiment of the resistance and retraction mechanism  150  also includes radial springs  158  (only one is shown in  FIG. 6 ) that engage the cable receiving spools  142 ,  144  to apply the retraction forces. The radial spring  158  is wound when the respective cable receiving spool  142  are rotated in the unwinding direction by the respective cable  132  moving toward the extended position (i.e., when the user pulls on the cables). When the user stops pulling on the cable  132 , the force stored in the wound radial spring  158  provides the retraction force that causes the cable receiving spool  142  to rotate in the winding direction, thereby winding and retracting the cable  132 . Other types of springs or resilient members may also be used in the resistance and retraction mechanism  150  to generate the retraction forces. Because the resistance wheel  152  is disengaged from the cable receiving spool  142  during rotation in the winding direction, the radial spring  158  generates the retraction force independent of the resistance force generated by the resistance wheel  152 . 
     As shown in  FIG. 6  and in greater detail in  FIGS. 7-9 , a locking cam gear mechanism  170  may be used to selectively engage the cable receiving spools  142 ,  144  and the resistance wheels  152 ,  154 . In the illustrated embodiment, the locking cam gear mechanism  170  is fixedly engaged to the resistance wheel  152 , for example, using one or more pins  171 , and is selectively engaged to the cable receiving spool  142 . For example, the cable receiving spool  142  includes a recessed region formed by an annular surface  141  and the locking cam gear mechanism  170  is received in the recessed region. 
     An embodiment of the locking cam gear mechanism  170  includes a cam gear  172  and one or more lock bearings  173  that engage the cam gear  172 . The cam gear  172  includes one or more cam surfaces  175  and bearing surfaces  177  that form one or more teeth  176 . The lock bearings  173  are located between the teeth  176  such that the cam surface(s)  173  engage the lock bearings  173  when the cam gear  172  rotates in one direction (as indicated by arrow  106 ) and engage the bearing surface(s)  177  when the cam gear  172  rotates in the opposite direction (as indicated by arrow  108 ). The cam surface  175  forms an acute angle relative to the annular surface  141  such that the lock bearing  173  wedges between the cam surface  175  and the annular surface  141  when rotating in the direction of arrow  106 . The bearing surface  177  forms a generally perpendicular angle relative to the annular surface  141  such that the lock bearing  173  rolls against the annular surface  141  when pushed by the bearing surface  177 . Thus, the cam gear  172  and the lock bearings  173  lock against the annular surface  141  of the cable receiving spool  142  when rotating in the direction of arrow  106  (i.e., the unwinding direction) and rotate freely with respect to the annular surface  141  when rotating in the direction of arrow  108  (i.e., the winding direction). One or more bearings  179 , such as thrust bearings, may be used to facilitate rotation of the cable receiving spool  142  and the locking cam gear mechanism  170 . 
     The locking cam gear  172  may also be fixedly secured to the resistance wheel  152  using other structures or by forming the cam gear  172  as one piece with the resistance wheel  152 . In other embodiments, the locking cam gear mechanism  170  may be fixedly engaged to the cable receiving spool  142  and selectively engaged with the resistance wheel  152 . Although the lock bearings  173  are shown as rods, they may also be balls or similar structures that will move with the cam gear  172  in one direction of rotation and lock with the cam gear  172  in the other direction of rotation. Further embodiments may use other types of mechanisms, such as ratchet mechanisms, that provide selective engagement in different directions of rotation. 
     Referring to  FIGS. 10 and 11 , another embodiment of an adjustable resistance exercise device  1000  is shown and described. In this embodiment, the adjustable resistance exercise device  1000  includes cable receiving spools  1042 ,  1044  and a resistance and retraction mechanism  1050  including resistance wheels  1052 ,  1054  located closer to an adjustment mechanism  1060 . The adjustable resistance exercise device  1000  also includes cable pulleys  1043 ,  1045  that guide cables  1032 ,  1034  to and from the cable receiving spools  1042 ,  1044 . In this embodiment, the cable receiving spools  1042 ,  1044  rotate in winding and unwinding directions that are opposite the winding and unwinding directions in the embodiment described above. The cable receiving spools  1042 ,  1044 , pulleys  1043 ,  1045  and resistance and retraction mechanism  1050  are mounted to a frame  1040  and provided within a platform  1010 , for example, as described above. 
     The adjustment mechanism  1060 , according to this embodiment, includes a gauge  1061  that allows a user to gauge the resistance adjustment. The gauge  1061  may be visible through an aperture  1017  in the platform  1010 . The gauge  1061  may be calibrated to indicate the approximate resistance (e.g., in pounds) applied to one or both sides of the exercise device  1000 . 
     As shown in greater detail in  FIG. 12 , the adjustment mechanism  1060 , according to this embodiment, also includes a threaded adjustment rod  1062  that threadably engages a slider  1064 , which is coupled to a tensioning wheel  1066  or similar structure. The tensioning wheel  1066  receives a resistance belt  1057  and moves the resistance belt  1057  to adjust the tension thereof and the resistance applied to the resistance wheels  1052 ,  1054 . In this embodiment, the gauge  1061  may include a dial  1063  located in the aperture  1017  of the platform  1010  and a pointer fixed to the slider  1064  and moving relative to the dial  1063 . The dial  1063  may include one or more markings or indicia to indicate a relative position of the slider  1064  and thus the relative resistance applied by the resistance belt  1057 . 
     The slider  1064  may be received in a guide portion  1041  extending from the frame  1040 , and a bolt  1065  or similar structure may extend from the slider  1064  to engage and move the tensioning wheel  1066 . A belt securing member  1067  may secure the resistance belt  1057  against a portion  1069  of the tensioning wheel  1066  to prevent the resistance belt  1057  from sliding when the resistance wheels  1052 ,  1054  rotate against the resistance belt  1057 . 
     Referring to  FIGS. 13-15 , a further embodiment of an adjustment mechanism  1360  is described. According to this embodiment, a tension belt  1357  is coupled to a tensioning wheel  1366  or similar structure using hardware such as a nut  1367  and threaded fastener  1368  (e.g., a bolt or socket head cap screw). The nut  1367  is held captive in a slot  1369  in the tensioning wheel  1366  and the threaded fastener  1368  extends through the belt  1357  and into the slot  1369  to threadably engage the nut  1367 . The adjustment mechanism  1360  also includes a slider  1364  coupled to the tensioning wheel  1366  as described above (see  FIG. 15 ). The slider  1364  may be made of a plastic material with a steel insert  1361  forming the threaded portion that receives the threaded rod. The slider  1364  may also be hollow with ribs  1363  ( FIG. 15 ) or may be solid. As shown in  FIG. 14 , the cable pulleys  1343 ,  1345  may be secured to the frame  1340  using fasteners, such as socket head cap screws, which may pass through the frame  1340  and the bottom of the platform. 
     Referring to  FIGS. 16 and 17 , one embodiment of a handle  1620  may include a strength member  1621  and a housing  1623  that encloses at least a portion of the strength member  1621 . The strength member  1621  is coupled to a cable  1630 , for example, through a cable coupling portion  1631  extending through a bottom of the handle  1620 . The strength member  1621  may be made of a metal or other suitable material capable of withstanding the forces applied to the handle  1620  during use. The housing  1623  may be made of a plastic or other suitable material and may include ribs  1627  that provide reinforcement. A handle grip  1625  may be rotatably mounted on the strength member  1621  such that the grip  1625  rotates when the user pulls on the handle  1620 . 
     Accordingly, the adjustable exercise device, consistent with the embodiments described herein, uses a resistance and retraction mechanism that provides a retraction force (when retracting a cable) independent of a resistance force (when extending a cable). Thus, the resistance force can be adjusted without changing the retraction force. 
     Consistent an embodiment, an adjustable resistance exercise device includes a support frame, at least one cable receiving spool rotatably coupled to the support frame, and at least one cable coupled to the cable receiving spool. A length of the cable is coiled around the cable receiving spool in a retracted position and the length of the cable extends from the cable receiving spool in an extended position. The cable receiving spool is rotatable in a winding direction when the cable is being retracted toward the retracted position, and the cable receiving spool is rotatable in an unwinding direction when the cable is being extended toward the extended position. The resistance exercise device also includes at least one adjustable resistance and retraction mechanism operably coupled to the cable receiving spool to apply an adjustable resistance force to the cable receiving spool and to apply a retraction force to the cable receiving spool independent of the adjustable resistance force. The resistance force resists rotation of the cable receiving spool in the unwinding direction to resist extension of the cable toward the extended position when the cable receiving spool is rotating in the unwinding direction. The resistance force is applied only when the cable receiving spool is rotating in the unwinding direction. The retraction force causes the cable receiving spool to rotate in the winding direction to retract the cable toward the retracted position when the cable receiving spool is rotating in the winding direction. 
     Consistent with another embodiment, a resistance exercise device includes a support frame, at least one resistance wheel rotatably coupled to the support frame, and at least one cable receiving spool rotatably coupled to the support frame and selectively engaged with the resistance wheel such that rotation of the cable receiving spool in an unwinding direction causes the resistance wheel to rotate and rotation of the cable receiving spool in a winding direction is independent of the resistance wheel. The resistance exercise device also includes at least one cable coupled to the cable receiving spool. A length of the cable is coiled around the cable receiving spool in a retracted position and the length of the cable extends from the cable receiving spool in an extended position. The resistance exercise device further includes at least one resistance member engaging the resistance wheel to resist rotation of the resistance wheel in the unwinding direction such that the cable resists extension toward the extended position and at least one retraction spring engaging the cable receiving spool to cause the cable receiving spool to rotate in the winding direction such that the cable retracts toward the retracted position. 
     Consistent with a further embodiment, an adjustable resistance exercise device includes a support frame, first and second cable receiving spools rotatably coupled to the support frame, and first and second cables coupled to the cable receiving spools, respectively. A length of each of the cables is coiled around the respective cable receiving spools in a retracted position and the lengths of each of the cables extend from the respective cable receiving spools in an extended position. Each of the cable receiving spools is rotatable in a winding direction when the respective cable is being retracted toward the retracted position. Each of the cable receiving spools is rotatable in an unwinding direction when the respective cable is being extended toward the extended position. The exercise device further includes at least one adjustable resistance and retraction mechanism operably coupled to the cable receiving spools to apply adjustable resistance forces to the cables and to apply retraction forces to the cables independent of the adjustable resistance forces. 
     While the principles of the invention have been described herein, it is to be understood by those skilled in the art that this description is made only by way of example and not as a limitation as to the scope of the invention. Other embodiments are contemplated within the scope of the present invention in addition to the exemplary embodiments shown and described herein. Modifications and substitutions by one of ordinary skill in the art are considered to be within the scope of the present invention, which is not to be limited except by the following claims.