Abstract:
A resistance training exercise device includes a stretchable cord having an internal cavity and a governor in the form of a limit band situated within that cavity and including first and second end segments. A retaining member attaches each of the end segments to the cord so as to impart stretching motion to the limit band when the cord is stretched during exercising. The retaining members provided at each end of the limit band each include a cup-shaped outer member and an inner, member having an outer peripheral surface. Each end segment of the limit band is positioned through an opening in the cup-shaped outer member and is secured to the inner member.

Description:
RELATED APPLICATIONS 
     This application is a continuation-in-part of application Ser. No. 12/928,786, filed on Dec. 20, 2010, which is a continuation-in-part of application Ser. No. 12/804,584, filed on Jul. 26, 2010 (abandoned), which is a continuation-in-part of application Ser. No. 12/546,085 filed on Aug. 24, 2009, now U.S. Pat. No. 7,819,787, which is a continuation-in-part of application Ser. No. 12/344,798, filed on Dec. 29, 2008, now U.S. Pat. No. 7,785,243. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to a resistance training exercise device, and more particularly, to a resistance training exercise device including a governor to limit the length of stretch of the device. 
     2. Description of Related Art 
     Resistance training is an extremely popular form of exercise; employing a variety of different devices. One of the more popular resistance training devices employs stretchable tubes or bands having a handles or other body securement means attached to opposed ends of the tube or band either directly or through attachment straps, carabineers and the like. To use this type of device, the user holds the handles or otherwise secures the tube to a part of the body to be exercised, and the user repeatedly stretches the tube to thereby increase the tension in the tube to provide resistance training. 
     One of the potential problems of concern is that the stretchable cord may break if stretched beyond its capacity. Such breakage can result in the cord snapping into contact with the user to cause serious bodily injury. 
     Prior art resistance training exercise devices including elastic cords also have attachment members, such as carabineers, to accommodate the attachment and use of a variety of different body engaging members, e.g., handles and straps thereto. Moreover, when exercising it is known to employ a number of elastic cords having varying levels of elasticity, to thereby change the workload imposed on the device during exercising. 
     It has been disclosed in prior art exercise cords to employ a non-destructive governor (i.e., restraining device) as part of the structure, to thereby limit the length of stretch of the outer cord for preventing the cord from breaking. 
     For example, an exercise band identified as “progym in a bag” is advertised on gofit.net, and includes a limit band inside of an outer, hollow, stretchable band. This device employs an outer, rigid plastic retaining member at each end for retaining a respective end of both the outer stretchable band and the inner limit band. Each of the outer members includes a base section that is internally threaded adjacent an open end thereof, and an plug section having external threads that cooperate with the threaded base section to permit the plug to be screwed into the base section. The opposed end of the plug includes a ring section to which a caribaneer, handle, etc. can be attached. An inner cup-shaped member is positioned in the base section of the outer retaining member below the upper threaded area of the base section to which the plug section is attached. The inner cup-shaped member has an opening in the base thereof through which the limit band is directed. The free end of the limit band is tied to a hollow, flat washer that has an outer diameter greater than the inner diameter of the cup-shaped member such that only a peripheral segment of the washer extends into the opening of the cup-shaped member, with a significant portion of the washer being outside the opening into the cup-shaped member. In this construction, the plug section is threaded into the base section to aid in preventing the washer from separating from the cup-shaped member; an action that otherwise could occur do to the fact that the washer only partially seats within the opening of the cup-shaped member. The construction of this latter exercise band is not well suited for use with a flexible tether, since it relies upon the use of the outer, rigid plastic retaining member to maintain the cup-shaped member and the washer in proper cooperation with each other. Moreover, the flat washer provides relatively sharp edges that engage the limit band in the region in which the washer and limit band are connected together and these edges can actually cut through or otherwise damage the limit band during use of the exercise band. 
     U.S. Pat. No. 7,819,787 also discloses a variety of different retaining devices for securing a governor within the interior of a hollow resistance training exercise device. However, none of these latter retaining devices employ an outer cup-shaped member cooperating with an inner retaining member. 
     Applicants believe that a need exists for improved retaining devices that can employ flexible tethers, that are economical to construct and that are less susceptible to breakage or damage than other such retaining devices. It is to such improved retaining devices that the present invention is directed. 
     The subject matter of U.S. Pat. No. 7,819,787 is incorporated by reference herein in its entirety. In addition, all of the other related applications/patents are incorporated by reference herein in their entirety. 
     SUMMARY OF THE INVENTION 
     A resistance training exercise device includes a stretchable cord having opposed first and second ends and includes an internal cavity. A flexible tether is secured adjacent each of the ends of the stretchable cord and each tether includes at least one compartment in which the first and second ends, respectively, of the cord are retained. A retaining member is provided within the internal cavity of the cord adjacent the first and second ends thereof, and this retaining member is located within the compartment of an adjacent tether. A sleeve is attached to the cord adjacent each of the first and second ends and at least a portion of the sleeve is located within the compartment of an adjacent tether. Each of the retaining members also is in the compartment of an adjacent tether and is located within a length of the sleeve that is located within the compartment of that adjacent tether. 
     A governor including a limit band is situated within the internal cavity of the stretchable band and includes opposed first and second end segments. These end segments are attached, respectively to the retaining members. 
     The retaining members in accordance with this invention aid in retaining the cord within the tethers and in retaining the opposed first and second end segments of the limit band attached to the cord so that the limit band moves, or stretches with the cord as the cord is being stretched during exercising; said limit band limiting the distance that the cord is capable of being stretched. 
     In accordance with the broadest aspects of this invention each of the retaining members includes a cup-shaped outer member and an inner member; preferably but not necessarily generally ball-shaped, located completely within the interior of the cup-shaped member. Each of the cup-shaped members includes a bottom wall and a peripheral wall, an outer surface of said peripheral wall engaging an inner surface of the cord and expanding the cord radially outwardly to assist in retaining the cord within the compartment of an adjacent tether. The bottom wall of each of the cup-shaped members has a passage through which a respective end segment of the limit band extends. Each of the end segments of the limit band is secured against movement to the inner member forming part of each of the retaining members, whereby the cup-shaped member cooperates with the inner member by supporting said inner member in a proper position within the interior of the cup-shaped member to assist in retaining the limit band in a proper position within the elastic cord and to insure that the limit band is expanded with the movement of the elastic cord. 
     In accordance with a preferred embodiment of this invention each of the retaining members includes a rigid, cup-shaped outer member and a rigid, inner member; preferably generally ball-shaped and having an outer peripheral surface free of sharp edges. Each of the cup-shaped members includes a bottom wall and a peripheral wall having an inner surface and an outer surface. The bottom wall of each of the cup-shaped members has a passage through which a respective end segment of the limit cord extends and the outer surface of the cup-shaped member engages the inner surface of the cord to expand the cord radially outwardly to assist in retaining the cord within the compartment of an adjacent tether. Each of the end segments of the limit band is secured against movement to the inner member forming part of each of the retaining members, said outer peripheral surface of the inner member of each of the retaining members being in tight frictional engagement with the inner surface of the peripheral wall of a respective cup-shaped member to thereby firmly retain the ball-shaped member and the end segment of the limit band secured thereto against relative movement to said stretchable cord when the cord is being stretched during exercising. 
     In a preferred embodiment of this invention the inner member is a generally ball-shaped, oblong member having a generally cylindrical central segment and opposed end segments, which preferably are rounded or curved. The central segment has an outer peripheral surface that provides frictional engagement with the inner surface of the peripheral wall of a respective cup-shaped member to firmly retain the generally ball-shaped member within the cup-shaped member to thereby prevent separation of the governor supported thereby and also to provide for the simultaneous movement of the governor with the elastic cord. 
     In the most preferred construction of this invention the inner member of each retaining member is a generally ball-shaped member including a channel in the outer peripheral surface thereof and each of the end segments of the limit band is retained within a channel of a respective ball-shaped member when secured to the respective ball-shaped member. Specifically, each of the end segments of the limit band is wrapped within the channel either once or multiple times; preferably twice, and most preferably is then knotted to itself to provide a firm attachment of the limit band to the ball-shaped member. 
     The firm attachment of the limit band to the inner member accompanied by the strong frictional engagement of the inner member within the outer cup-shaped member in the most preferred embodiments of this invention provide an extremely unique, simple and reliable attachment mechanism of the limit band to the elastic, stretchable cord that functions to cause the limit band to stretch with the cord until the limit band reaches it final level of elongation and to retain the cord connected to the tether. 
     In accordance with the broadest aspect of this invention the governor can be either an elastic or inelastic limit band. In either event, the governor needs to be sufficiently strong to prevent it from breaking when it reaches its stretched limit, and further needs to reach the stretched limit prior to the outer elastic band being stretched to such a high degree as to cause it to break or otherwise fail. 
     In the most preferred embodiment of this invention the governor is in the form of a multifilament polymer strand that is non-elastic; having a length that is multiple times (e.g., 4) greater than the relaxed length of the elastic cord. Any suitable polymer fibers can be employed to form the filament strand; most preferably Dyneema synthetic fibers. In the preferred embodiment of this invention the multifilament polymer strand is maintained in a crunched or collapsed condition within the interior of the exercise device prior to use. 
     Reference throughout this application to “generally ball-shaped” or “ball-shaped” in describing a part of the retaining member of this invention is intended to include both spherical and non-spherical constructions, unless specifically stated otherwise. In fact, in the preferred embodiment the ball-shaped member is generally oblong, as will be described in greater detail hereinafter. 
     Other objects and advantages of this invention will become apparent by referring to the description of the drawings which follows, taken in conjunction with the detailed description of this invention, which follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be described in conjunction with the following drawings in which like reference numerals designate like elements and wherein: 
         FIG. 1  is an isometric view of a representative resistance training exercise device employing a governor in accordance with this invention; 
         FIG. 2  is a view along line  2 - 2  of  FIG. 1 , partially in section, showing certain details of construction in accordance with this invention; 
         FIG. 3  is a sectional view similar to that shown in  FIG. 2 , but with additional parts in section to show details of construction of the unique retaining member in accordance with the most preferred embodiment of this invention; 
         FIG. 4  is an enlarged view of the circled area identified as “ 4 ” in  FIG. 3 ; 
         FIG. 5  is an exploded isometric view showing details of construction of the preferred retaining member in accordance with this invention. 
         FIG. 6  is an elevational view showing a limit band attached to an inner member of a retaining member in accordance with an additional embodiment of this invention; 
         FIG. 7  is an isometric view with the cup-shaped member partially broken away showing the manner in which the inner member illustrated in  FIG. 6  cooperates with an outer cup-shaped member to provide a retaining member in accordance an embodiment of this invention; and 
         FIG. 8  is an end elevational view showing a limit band attached to an inner member of a retaining member in accordance with still an additional embodiment of this invention. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     A resistance training exercise device employing the most preferred features of the present invention is generally indicated at  10  in  FIG. 1 . This device includes an elastic, elongated hollow cord  12  having tethers  14  secured to each end of the cord  12  and further including a clip or carabineer  16  secured to the free end of each of the tethers. 
     As can be seen best in  FIG. 1 , the preferred tether  14  is stitched at  18  to provide two compartments; one for receiving and retaining an adjacent end of the cord  12  and the other compartment for retaining the clip or carabineer  16 . Each of the tethers  14  preferably is formed of a polymer, such as a nylon or nylon-like material that is secured to an adjacent end of the cord  12 . 
     The elastic, elongated hollow cord  12  comprises a rubber or rubber-like material having a predetermined level of elasticity corresponding to the amount of pulling force needed to stretch the cord a desired distance. The level of elastic resistance in the cord dictates the tension force of the cord, which is represented in pounds. Accordingly, the cord  12  is designed with an average workout weight in pounds based on the cord&#39;s modulus of elasticity, which can be indicated on the cord&#39;s corresponding clip  16  if desired. 
     It should be understood that the clips or carabineers  16  are employed for attaching a variety of different body engaging members thereto, such as a handles, an ankle or wrist straps, a ropes, bars, etc. 
     Referring to  FIGS. 1-3 , the tethers  14  are each secured to a respective, adjacent end of the cord  12  by a grommet  20 , retaining member  22  and strain release sleeve  24 . The retaining member  22  is inserted into hollow passage  13  at each end of the cord  12  and functions, in part, to block the grommet  20  from slipping off of the cord  12 . The strain relief sleeve  24  fits tightly over each end of the cord  12  that contain the retaining member  22  to thereby reinforce the cord  12  and retaining member  22  to thereby increase the stress and strain tolerance of the cord. The sleeve  24  preferably comprises an elastic sleeve member that stretches and mounts over the opposed ends of the cord that contain the retaining member  22 . The elastic sleeve members  24  stretch and conform to the shape of the retaining member  22  to reinforce and increase the tolerance level of stress, strain and/or shearing forces. 
     In an alternative embodiment the strain relief sleeve  24 , instead of being a separate member, may be formed or provided by a portion of the elastic cord  12  that is folded back over itself to surround the region of the cord including the retaining member  22  therein. 
     Referring specifically to  FIG. 1  it should be noted that clip  16  can be of any conventional design and, in the illustrated embodiment, includes a hooked body  30 , a spring loaded or biasing member  32  and a smaller, tether connecting end  34 . In the illustrated embodiment an O-ring  36  is provided in the smaller tether connecting end  34  of the clip  16  to receive the tether end for reinforcement and smooth support of the tether  14  in a manner that reduces friction and the risk of damage to the tether during exercising. Access to the opening in the clip  16  is controlled by the biasing member  32 , which facilitates the clipping of a body engaging member (e.g., a handle or strap) to the clip. 
     It should be noted that the various features of the resistance training exercise device  10  described thus far are disclosed in detail in U.S. Pat. No. 7,819,787, previously incorporated by reference herein and assigned to the assignee of the present application. 
     Turning specifically to  FIGS. 2-5 , the resistance training exercise device  10  includes a governor in the form of a limit band  40  housed within the elastic cord  12  and secured to each end of the cord  12  by retaining members  22 . The governor  40  limits the stretching of the cord  12  to a predetermined length to prevent the cord  12  from breaking. The limit band  40  can be of any desired construction, and can be made of a semi-elastic material having substantially less elasticity than the elastic cord  12  or, in the most preferred embodiment, is substantially inelastic. In the preferred embodiment of this invention, the limit band  40  is a multi-filament polymer strand, most preferably made from Dyneema synthetic fibers. 
     Due to the fact that the preferred limit band  40  is inelastic and has a length multiple times greater than the relaxed length of the hollow cord (e.g. 4 times greater) it is retained within the interior passage  13  of the hollow cord  12  in a crunched or bunched-up condition. 
     It should be noted that the limit band  40  has a higher tensile strength than the elastic cord  12  to thereby stop the cord from stretching without the limit band breaking. Although the limit band  40  may have some elasticity, in the most preferred embodiment of this invention it is inelastic and is crunched or bunched up in the cord when the cord is in a relaxed condition. 
     As can be seen best in  FIGS. 4 and 5 , the most preferred retaining member  22  of this invention is of a unique construction including a rigid cup-shaped outer member  50  including a bottom wall  52  and a peripheral side wall  54 . The cup-shaped member includes an opening or passage  56  in the bottom wall through which limit band  40  extends. In accordance with the preferred embodiments of this invention the cup-shaped member  50  can be made of any desired rigid material, e.g., plastic, hard rubber, etc. and most preferably is made from a polyolefin, such as polypropylene. 
     As can be seen best in  FIGS. 2-4 , the peripheral side wall  54  of the outer member also includes an inner surface  58 , and a rigid inner member; preferably a substantially ball-shaped member  60 , is forced into tight frictional engagement with said inner surface. Although this is the most preferred arrangement in accordance with the broadest aspects of this invention the inner member may not be in tight frictional engagement with the inner surface of the cup-shaped member. 
     As can be seen best in  FIGS. 4 and 5 , in the most preferred embodiment of this invention the substantially ball-shaped member  60  preferably is of a generally oblong configuration including a central cylindrical section  62  and opposed rounded sections  64 . A channel  66  is provided in the outer periphery of the ball-shaped member  60 , preferably extending continuously about the entire periphery thereof. The ball-shaped member can be made of any suitable material; most preferably of the same material employed to make the cup-shaped member  50 . 
     As can be seen best in  FIGS. 4 and 5 , the governor, in the form of a multi-filament limit band  40 , is positioned through the passage  56  in the bottom wall of the cup-shaped outer member, is wrapped tightly about the ball-shaped member  60  in the channel  66  thereof, and is then tied or knotted to itself, as indicated at  68 . The ball-shaped member  60  with the limit band  40  secured thereto is then forced into the opening in the cup-shaped member  50  to provide a tight frictional engagement between the outer peripheral wall of the cylindrical section  62  of the ball-shaped member  60  and the inner surface  58  of the side wall  54  of the cup-shaped outer member  50 . 
     The provision of the channel  66  in the ball-shaped member  60  in accordance with the most preferred embodiment of this invention permits the limit band  40  to be wrapped about the ball-shaped member without interfering with the ability to provide tight frictional engagement between the outer periphery of the cylindrical section  62  of the ball-shaped member and the inner surface of the side wall  54  of the cup-shaped outer member  50 . With this arrangement the likelihood of damaging the limit band as a result of frictional rubbing engagement with the inner surface of the cup-shaped outer member is minimized, as compared to simply wrapping the limit band about an un-channeled surface of the inner retaining member  60 . 
     The tight connection of the limit band  40  with the substantially ball-shaped member  60  in combination with the additional tight frictional engagement of the ball-shaped member  60  with the inner surface  58  of the side wall  54  of the cup-shaped member  50  provides an extremely reliable connection between the limit band  40  and the elastic, elongated hollow cord  12 . 
     Although the inner member  60  preferably is a ball-shaped member as described in detail above, it is within the broadest aspects of this invention to employ an inner member of other shapes and constructions. 
     For example, referring to  FIGS. 6 and 7 , an inner member  70  of a retaining member can be completely spherical and have a continuous, outer surface free of any channel for receiving the limit band  40  therein. In this embodiment, one of the end segments of the limit band  40  is wrapped about the outer periphery of the inner member and than knotted to itself at  72 . The inner spherical member  70 , with the limit band  40  secured about the periphery thereof, is then retained within outer, cup-shaped member  80  ( FIG. 7 ), which can be of the same construction as the outer cup-shaped member  50  of the preferred embodiment of this invention. In accordance with the broadest aspects of this invention the inner member  70  may not need to be maintained in frictional engagement with the inner surface of the cup-shaped member  80 , although in the most preferred embodiment of the invention a tight frictional engagement is maintained. 
     It should be noted that features of the embodiment shown in  FIGS. 6 and 7 , as described above, are the same as in the embodiment shown in FIGS. 27 and 28 of parent application Ser. No. 12/928,786, the subject matter of which already has been incorporated by reference herein and constitutes the joint invention of the inventors specified herein. 
     Referring to  FIG. 8 , as an alternative to wrapping the limit band about the outer periphery of the spherical member  70 , as shown in  FIGS. 6 and 7 , a central passage  74  can be provided diametrically through the spherical member  70  for receiving an end segment of the limit band. In this latter embodiment the distal end of the end segment, after passing through the central passage, is knotted to itself at  76  to retain the limit band within the spherical member. Thereafter, the spherical member  70  is then inserted into the cup-shaped member  80 . As in all of the previously discussed embodiments, although in accordance with the broadest aspects of this invention the inner spherical member  70  may not be maintained in tight frictional engagement with the inner surface of the cup-shaped member  80 , in the most preferred embodiment such a tight frictional engagement is maintained to provide an extremely rigid and reliable retaining member construction. 
     Also, in accordance with the broadest aspects of this invention the cup-shaped members  50 ,  80  can have a variety of different configurations, e.g., spherical, cone-shaped, tapered, etc.; the configuration not being limited to a configuration employing a flat bottom wall and a cylindrical side wall. The important feature is that the cup shaped member be capable of housing an inner retaining member therein; preferably frictionally engaging the inner retaining member to which the limit band is attached. 
     While the invention has been described in detail and with reference to specific examples thereof, it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.