Abstract:
A safety device provides a retractable gripping device for use in conjunction with walking assistance devices such that a user may safely navigate on slippery surfaces. An activating mechanism is provided for user convenience. A locking mechanism moves into a locked position. To deactivate the gripping device, the user again activates a deactivating device to return the gripping device back to its retracted, deactivated position. The gripping device is configured such that it may be used in conjunction with existing walking assistance devices. The retractable gripping mechanism and locking device are preferably controlled by the user with minimal effort, with the control mechanism positioned at or near where the users hands are positioned during use.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application relates to and claims priority from U.S. Provisional Patent Application Ser. No. 61/526,924 filed Aug. 24, 2011 and U.S. Provisional Patent Application Ser. No. 61/637,667 filed Mar. 24, 2012, the entire contents of each of which are incorporated herein fully by reference. 
     
    
     FIGURE FOR PUBLICATION 
       [0002]    
       FIG. 9A 
     
       BACKGROUND OF THE INVENTION 
       [0003]    1. Field of the Invention 
         [0004]    The present invention relates to a safety apparatus and method for preventing slipping of walking assistance devices such as crutches, canes, walkers, and/or other similar walking support devices. More particularly, the present invention provides a retractable gripping device for use in conjunction with a walking assistance device such that a user may safely navigate on wet, icy or otherwise slippery surfaces. A corresponding method of preventing slipping of a walking support device is also provided. 
         [0005]    2. Description of the Related Art 
         [0006]    Walking assistance devices, such as crutches, canes, walkers, and other similar devices have been used for years by various people needing assistance walking and/or other physical support. A user of these walking assistance devices faces his or her greatest challenge when walking on wet, icy, or otherwise slippery surfaces. During use of such a device it is important that the support provided by the device is steady so that the user can safely navigate on the device without risk of injury, especially when the walking assistance device is used on wet, icy, or otherwise slippery surfaces because such surfaces may cause the tip of the walking assistance devices to slip (e.g., to the front, to the back, or to the side) causing the user to lose balance and fall possibly leading to injury. 
         [0007]    With regard to the configuration of the tips for such walking assistance devices, the prior art discloses friction based tips having a lower surface or tread piece which is divided or separated into a plurality of segments, each of which has an edge or portion thereof to provide a separate frictional engagement with the ground or other supporting surface when the tip is flexed. The related art also discloses tips having a screw-in-type receiver for the shaft of the walking assistance device (small spike). The lower surface of the tread piece includes a plurality of downwardly or outwardly depending projections or fingers for receiving and flexing about small articles while maintaining traction with the ground or other supporting surface. Moreover, typical prior art tips are made of natural rubber because they provide superior performance on a variety of surfaces. However, such natural rubber tips typically provide insufficient traction on smooth wet or otherwise slippery surfaces. 
         [0008]    Over the years, many different types of tips to be employed on the bottom of crutches, canes, walkers and the like, have been provided in an attempt to help prevent slipping on wet, icy or otherwise slippery surfaces. One such known configuration consists of a base, an upholding pole, and a mantle. At the top of the base, there is a cavity for engaging with the ball-shaped end piece at the end of the upholding pole. The end piece will then be able to adjust to follow the lay of surface by changing its supporting angle moderately and thus minimize the risk of slipping. As another attempt at a solution to this problem, the prior art also discloses inserting one or more disks or strips of non-skid material, such as a metal wire brush, into a rubber tip tread piece in order to improve traction on wet surfaces. Still other attempts to solve this problem included use of various materials to replace the rubber tip. However, natural rubber has an advantage on substantially dry or substantially rough surfaces in that it sloughs off its surface layer when abraded with each step and presents a clean, tacky surface to the supporting surface, in the nature of a rubber pencil eraser. Other material did not prove to be suitable replacements for natural rubber. However, none of the known tips have adequately alleviated this slipping problem. 
         [0009]    Accordingly, there is a need for an improved crutch, cane, walker or other walking assistance device that provides added safety to users on icy or other slippery surfaces. Further, there is also a need for such an improved crutch that has an easy to use retractable gripping device that a user can activate and deactivate during use of the crutch, cane, walker or other walking assistance device. 
       SUMMARY AND ASPECTS OF THE INVENTION 
       [0010]    The invention relates to a safety device for use with walking assistance devices such as crutches, canes, walkers and the like. More particularly, the present invention provides a retractable gripping device for use in conjunction with a walking assistance device such that a user may safely navigate on slippery or icy surfaces. In a preferred embodiment, to activate the gripping device, the user of the crutch must push the activating knob down and turn it in the clockwise direction such that locking mechanism moves into the locked position. To deactivate the gripping device, the user again pushes down the knob and turns it in a counter-clockwise direction such that a spring internal to the lower leg portion of the crutch will return the gripping device back to its retracted, deactivated position. Preferably, the gripping device is configured such that it may be used in conjunction with existing walking assistance devices, with only minor adjustments or modifications without altering the basic design of the walking assistance device. Also, the retractable gripping mechanism and locking device are preferably controlled (i.e., activated or deactivated) by the user with minimal effort, with the control mechanism preferably positioned at or proximate near where the users hands are conveniently positioned on the walking assistance device. 
         [0011]    In a preferred embodiment of the present invention, disclosed is an apparatus for a retractable gripping device for use with a walking assistance device (e.g., forearm crutch, an underarm crutch, a platform crutch, a strutter crutch, a cane, a walking stick, a walker, etc.), wherein the apparatus comprises a shaft that is made of a rigid material, the shaft having an upper and lower end, wherein the lower end has a tip positioned thereon, a control or activating knob or handle (e.g., a round knob, a knurled knob, an oval knob, a triangular knob, a straight handle, a curved handle, etc.) positioned at the upper end of the shaft, a gripping mechanism positioned at the lower end of the shaft, a rod position longitudinally within the shaft, the rod connecting the knob and the gripping mechanism for providing a gripping action to a surface on which the walking assistance device is used, and a locking mechanism positioned on the rod between the upper and lower ends of the shaft such that when in a locked position the locking mechanism holds the gripping means in position extending through the tip, wherein the gripping mechanism comprises a rigid anti-slip surface, and wherein the locking mechanism is activated by exerting a downward force on the control knob and then rotating the control knob. 
         [0012]    Optionally, the longitudinal position of the locking mechanism is controlled by at least one spring, wherein the spring exerts an upward force on the rod. In such an embodiment, the spring is positioned substantially near the locking mechanism, and/or substantially near said control knob, and/or substantially near said tip. Preferably, the rod is supported within the shaft on the upper end by a press fit bushing. In the embodiment for use with a crutch, the crutch preferably comprises at least two generally straight upper tubes or legs positioned substantially parallel to each other, a shoulder pad, preferably fabricated of elastomeric material, positioned at the top of each of the two tubes thereby connecting them in a substantially parallel configuration, and a hand grip, preferably fabricated of elastomeric material and including an axial aperture extending there through, positioned between the two tubes. In such an embodiment, the retractable gripping device is positioned longitudinally between and secured to a lower end of the straight upper legs or tubes such that the control knob or handle is located near the hand grip and the tip is located at the lowest end of the crutch. Optionally, the vertical position of the retractable gripping device is adjustable by engaging to at least one pair of matching holes on the two upper legs or tubes. 
         [0013]    It is therefore an object of the present invention to provide a retractable gripping device for use in conjunction with a crutch such that a user may safely navigate on wet, icy or otherwise slippery surfaces. 
         [0014]    It is an object of the present invention to provide a retractable gripping device that is adaptable for use in conjunction with existing crutches, with only minor adjustments or modifications without altering the basic design of the crutches, such that a user may safely navigate on wet, icy or otherwise slippery surfaces. 
         [0015]    It is an object of the present invention to provide a retractable gripping device for use in conjunction with a crutch such that the retractable gripping mechanism and locking device may be controlled or activated by the user with minimal effort, as well as be easily controlled or deactivated in a similar manner. In such an embodiment, the activating mechanism is preferably positioned such that the user may control or activate it while continuing to utilize the crutches (e.g., without having to turn over the crutches). 
         [0016]    It is an object of the present invention to provide a retractable gripping device that is adaptable for use as a replacement kit for use in conjunction with existing canes, walkers, and other walking assistance devices. 
         [0017]    It is an object of the present invention to provide a retractable gripping device having a locking device, for example, like a twist and pivot mechanism or an indexed pressure (pen-type)-click mechanism. 
         [0018]    The above and other aspects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    A further understanding of the present invention can be obtained by reference to a preferred embodiment set forth in the illustrations of the accompanying drawings. Although the illustrated preferred embodiment is merely exemplary of methods, structures and compositions for carrying out the present invention, both the organization and method of the invention, in general, together with further objectives and advantages thereof, may be more easily understood by reference to the drawings and the following description. The drawings are not intended to limit the scope of this invention, which is set forth with particularity in the claims as appended or as subsequently amended, but merely to clarify and exemplify the invention. 
           [0020]    For a more complete understanding of the present invention, reference is now made to the following drawings in which: 
           [0021]      FIG. 1A  shows a front plan view of conventional walking crutch; 
           [0022]      FIG. 1B  shows a front plan view of a walking crutch having a retractable gripping device in accordance with a preferred embodiment of the invention; 
           [0023]      FIG. 2A  shows a front plan view of the walking crutch shown in  FIG. 1B  having a retractable gripping device with the retractable gripping device in the retracted or deactivated position; 
           [0024]      FIG. 2B  shows a front plan view of the walking crutch shown in  FIG. 1B  having a retractable gripping device with the retractable gripping device in the extended or activated position; 
           [0025]      FIG. 2C  shows an enlarged view of the lower end of the walking crutch shown in  FIG. 2A ; 
           [0026]      FIG. 2D  shows an enlarged view of the lower end of the walking crutch shown in  FIG. 2B ; 
           [0027]      FIG. 3A  shows an exposed front plan view of the walking crutch shown in  FIG. 1B  having a retractable gripping device with the retractable gripping device in the retracted or deactivated position, and further showing the internal components of the retractable gripping device in accordance with a preferred embodiment of the invention; 
           [0028]      FIG. 3B  shows an exposed front plan view of the walking crutch shown in  FIG. 1B  having a retractable gripping device with the retractable gripping device in the extended or activated position, and further showing the internal components of the retractable gripping device in accordance with a preferred embodiment of the invention; 
           [0029]      FIG. 3C  shows an enlarged view of the upper end of the retractable gripping device shown in  FIG. 3B ; 
           [0030]      FIG. 3D  shows an enlarged view of the lower end of the retractable gripping device shown in  FIG. 3B ; 
           [0031]      FIG. 4A  shows a side view of conventional walker; 
           [0032]      FIG. 4B  shows a side view of a walker having a retractable gripping device in accordance with a preferred embodiment of the invention; 
           [0033]      FIG. 5A  shows a side view of the walker shown in  FIG. 4B  having a retractable gripping device with the retractable gripping device in the retracted or deactivated position; 
           [0034]      FIG. 5B  shows a side view of the walker shown in  FIG. 4B  having a retractable gripping device with the retractable gripping device in the extended or activated position; 
           [0035]      FIG. 5C  shows an enlarged view of the lower end of one leg of the walker shown in  FIG. 5A ; 
           [0036]      FIG. 5D  shows an enlarged view of the lower end of one leg of the walker shown in  FIG. 5B ; 
           [0037]      FIG. 6A  shows an exposed partial side view of the walker shown in  FIG. 4B  having a retractable gripping device with the retractable gripping device in the retracted or deactivated position, and further showing the internal components of the retractable gripping device in accordance with a preferred embodiment of the invention; 
           [0038]      FIG. 6B  shows an exposed partial side view of the walker shown in  FIG. 4B  having a retractable gripping device with the retractable gripping device in the extended or activated position, and further showing the internal components of the retractable gripping device in accordance with a preferred embodiment of the invention; 
           [0039]      FIG. 6C  shows an enlarged view of the upper end of the retractable gripping device shown in  FIG. 6B ; 
           [0040]      FIG. 6D  shows an enlarged view of the lower end of the retractable gripping device shown in  FIG. 6B ; 
           [0041]      FIG. 7A  shows an exposed front plan view of an alternative embodiment of the walking crutch shown in  FIG. 1B  having a retractable gripping device with the retractable gripping device in the retracted or deactivated position, and further showing the internal components of the retractable gripping device in accordance with the alternative embodiment of the invention; 
           [0042]      FIG. 7B  shows an exposed front plan view of the walking crutch shown in  FIG. 7A  having a retractable gripping device with the retractable gripping device in the extended or activated position, and further showing the internal components of the retractable gripping device in accordance with the alternative embodiment of the invention; 
           [0043]      FIG. 7C  shows an enlarged view of the upper end of the retractable gripping device shown in  FIG. 7B ; 
           [0044]      FIG. 7D  shows an enlarged view of the lower end of the retractable gripping device shown in  FIG. 7B ; 
           [0045]      FIG. 8A  shows an exposed partial side view of an alternative embodiment of the walker shown in  FIG. 4B  having a retractable gripping device with the retractable gripping device in the retracted or deactivated position, and further showing the internal components of the retractable gripping device in accordance with the alternative embodiment of the invention; 
           [0046]      FIG. 8B  shows an exposed partial side view of the walker shown in  FIG. 8A  having a retractable gripping device with the retractable gripping device in the extended or activated position, and further showing the internal components of the retractable gripping device in accordance with the alternative embodiment of the invention; 
           [0047]      FIG. 8C  shows an enlarged view of the upper end of the retractable gripping device shown in  FIG. 8B ; 
           [0048]      FIG. 8D  shows an enlarged view of the lower end of the retractable gripping device shown in  FIG. 8B ; 
           [0049]      FIG. 9A  shows an exposed front plan view of a second alternative embodiment of the walking crutch shown in  FIG. 1B  having a retractable gripping device with the retractable gripping device in the retracted or deactivated position, and further showing the internal components of the retractable gripping device in accordance with the second alternative embodiment of the invention; 
           [0050]      FIG. 9B  shows an exposed front plan view of the walking crutch shown in  FIG. 9A  having a retractable gripping device with the retractable gripping device in the extended or activated position, and further showing the internal components of the retractable gripping device in accordance with the second alternative embodiment of the invention; 
           [0051]      FIG. 9C  shows an enlarged view of the upper end of the retractable gripping device shown in  FIG. 9B ; 
           [0052]      FIG. 9D  shows an enlarged view of the lower end of the retractable gripping device shown in  FIG. 9B ; 
           [0053]      FIG. 10A  shows a partial exposed side view of the walker shown in  FIG. 5A  having an alternative embodiment of the retractable gripping device with the retractable gripping device in the retracted or deactivated position; 
           [0054]      FIG. 10B  shows a partial exposed side view of the walker shown in  FIG. 10A  having an alternative embodiment of the retractable gripping device with the retractable gripping device in the extended or activated position; 
           [0055]      FIG. 10C  shows an enlarged view of the upper end of the retractable gripping device shown in  FIG. 10B ; 
           [0056]      FIG. 10D  shows an enlarged view of the lower end of one leg of the walker shown in  FIG. 10B ; and 
           [0057]      FIG. 11  shows an exposed side view of the walker shown in  FIG. 4B  having an alternative embodiment of the retractable gripping device with the retractable gripping device in the extended or activated position. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0058]    As required, a detailed illustrative embodiment of the present invention is disclosed herein. However, techniques, systems, compositions and operating structures in accordance with the present invention may be embodied in a wide variety of sizes, shapes, forms and modes, some of which may be quite different from those in the disclosed embodiment. Consequently, the specific structural and functional details disclosed herein are merely representative, yet in that regard, they are deemed to afford the best embodiment for purposes of disclosure and to provide a basis for the claims herein which define the scope of the present invention. 
         [0059]    Reference will now be made in detail to several embodiments of the invention that are illustrated in the accompanying drawings. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale. For purposes of convenience and clarity only, directional terms, such as top, bottom, up, down, over, above, below, etc., or motional terms, such as forward, back, sideways, transverse, etc. may be used with respect to the drawings. These and similar directional terms should not be construed to limit the scope of the invention in any manner. 
         [0060]    Referring first to  FIG. 1 , shown is a comparison of a standard crutch compared to the new gripping crutch for slippery conditions.  FIG. 1A  shows the standard crutch. The standard crutch  2  typically has an upper shaft made of two tubes or stems. A hand grip  6  of the crutch  2  is positioned generally in the center of the length of the crutch  2 , and is preferably adjustable like many other conventional crutches. The standard crutch  2  also comprises lower shaft  8  preferably comprised of one aluminum tube that constitutes a leg part of the crutch  2 , and extended from the upper shaft toward to ground surface. Preferably, the position of the lower shaft  8  with respect to the upper shaft is adjustable. An armrest  4  at the top of the crutch  2  is preferably fabricated with elastomeric material, the armrest  4  having a slightly indented upper surface. A hand grip ( 3 ) fabricated of elastomeric material and including an axial aperture extending there through. The hand grip being positioned between the two upper tubes of crutch  2 . The vertical position of the hand grip  6  may be adjusted by engaging the hand grip  6  to one pair of matching holes on the two upper tubes at the same vertical level. At the lower end of lower tube  8  there is preferably a tip  10  positioned on the end of the lower tube  8 . Tip  10  is typically made of a rubber-like material for engagement on typical surfaces, such as tile, marble, wood, pavement, cement, etc. 
         [0061]    In accordance with the present invention, lower tube or shaft  8  of a standard crutch  2  is replaced with a retractable gripping device  18  as shown in  FIG. 1B . Here, shown is a crutch  12  that incorporates the retractable gripping device  18  according to the invention. Preferably, retractable gripping device  18  comprises a shaft  26  that is made of a rigid material, having an upper and lower end, a control knob  28  positioned at the upper end of the shaft  26 , a gripping means  22  positioned at the lower end of the shaft  26 , a rod  27  position longitudinally within the shaft  26  connecting the knob  28  and the gripping means  22  for providing a gripping action to a surface on which the crutch is used, and a locking mechanism  24  positioned on the rod  27  at a location between the knob  28  and the gripping means  22  such that when in a locked position the locking mechanism  24  holds the gripping means  22  in position extending through the tip  20 . During operation, the locking mechanism  24  is activated by the user exerting a downward force on the control knob  28  and then rotating the control knob in either a clockwise or counter-clockwise direction. Also, as shown, the modifications are made at the lower end of the upper portion of crutch  12 . That is, the lower portion of a standard crutch is replaced with a new lower portion having the retractable gripping device  26 . Also, the lower portion is preferably extended upward toward the hand grip  16  used by the user such that adjustment of the retractable gripping device  26  is easily controlled by the user wile he/she is using the crutch  12 . Preferably, incorporation of the lower leg having the retractable gripping device  26  does not alter the height adjustability of the crutch  12 . 
         [0062]    Referring next to  FIG. 2A , depicted is the crutch  12  in accordance with the preferred embodiment of the present invention as shown in  FIG. 1B , with the gripping device  26  deactivated and in its retracted position. In  FIG. 2A , shown is a front plan view of the walking crutch  12  having a retractable gripping device  26 . As depicted more clearly in  FIG. 2C , an enlarged view of the lower end of the walking crutch  12  shown in  FIG. 2A , pin or screw type locking mechanism  25  is in the raised and retracted position within bored opening  37 . In this position, the gripping mechanism  22  is in a retracted position such that it does not extend or protrude through the bottom of tip  20 . To activate the retractable gripping device  26 , the user of the crutch  12  must push the activating knob  28  down (which may be any convenient shape or size to provide easy access to and activation of the knob) such that the locking mechanism  25  moves to the lower end of bored opening  37 . Once in that position, the user need only turn knob  28  in a clockwise direction until locking mechanism  25  moves into a lower locked position within bored opening  37 . 
         [0063]    To deactivate the gripping device, the user must again push down the knob and turn it in a counter-clockwise direction such that a spring internal to the lower leg portion of the crutch will return the gripping device back to its retracted, deactivated position. As shown, when not activated a retaining spring maintains the gripping device in the retracted, deactivated upward position. Also as shown, when the gripping device is activated in the extended position, the spring is compressed. When the knob is turned clockwise, the spring will hold the gripping device in the locked position. All downward pressure applied to the gripping device will maintain it in the locked position in conjunction with the spring. 
         [0064]    Turning to  FIG. 2B , depicted is the crutch  12  shown in  FIG. 1B , with the gripping device  26  activated and in its extended position. As depicted more clearly in  FIG. 2D , an enlarged view of the lower end of the walking crutch  12  shown in  FIG. 2B , pin or screw type locking mechanism  25  is in the activated and in its extended position within bored opening  37  such that gripping mechanism or surface  22  is protruding through the bottom of tip  20 . To deactivate the gripping device  26 , the user must again push down the knob  28  and turn it in a counter-clockwise direction such that a spring  34  ( FIG. 3A-D ) internal to the lower leg portion of the crutch  12  will return the gripping device  26  back to its retracted, deactivated position. As shown in  FIG. 3A , when not activated a retaining spring  34  maintains the gripping device  26  in the retracted, deactivated upward position. As shown in  FIGS. 3B-C , when the gripping device  26  is activated in the extended position, the spring  34  is compressed. When the knob  28  is turned clockwise, the spring  34  will hold the gripping device  26  in the locked position. All downward pressure applied to the gripping device  26  will maintain it in the locked position in conjunction with the spring  34 . 
         [0065]    More particularly,  FIGS. 3A-C  show the internal components of the retractable gripping device  26  in accordance with a preferred embodiment of the invention. In particular, gripping device  26  preferably comprises knob or handle  28 , shaft or tube  18  having openings at either end as well a bored opening  37 , rod  32 , locking mechanism  25 , gripping surface or mechanism  22 , and foot  20 . Optionally, a spring  34 , and bushings  30  and  36  may be employed. Spring  34  may optionally be positioned below the locking mechanism  25  such that the spring  34  would exert an upward force on the rod  32  to maintain the gripping device  26  in either the activated or deactivated position depending on the position of control knob  28  and locking mechanism  25 . Alternatively, the spring may be located at or near the top of gripping device  26 . Similarly, spring  34  would exert an upward force on the rod  32  at or near the control knob  28  to maintain the gripping device  26  in either the activated or deactivated position depending on the position of control knob  28  and locking mechanism  25 . Also, in an alternative embodiment of the invention, rod  32  and gripping mechanism  22  may be constructed as a single integrated component, unlike the two separate components as in the preferred embodiment. 
         [0066]    As shown in  FIGS. 1-3 , the retractable gripping device  26  is preferably configured as a twist-and-pivot retractable locking system. As described above in greater detail, the twist and pivot retractable gripping device is activated (i.e., extended) or deactivated (i.e., retracted) by pushing down on the control knob  28  and twisting the control knob  28  to further twist the locking mechanism  25  such that it pivots and locks into either the activated or deactivated position. In an alternative embodiment, a click pen type retractable system may be used such that the user merely has to press down on control knob  28  to activate the gripping mechanism  22 , and then press down on knob  28  again to deactivate the gripping mechanism  22 . 
         [0067]    Turning next to  FIGS. 4-6 , depicted is another type of walking assistance device for which the present invention may be used.  FIG. 1A  depicts a conventional walker  40  which consists of a series of interconnected tubes, bars, pipes or rods to form a frame that a user can easily and safely use to support a good portion of his/her weight while attempting to walk around. Typically, such conventional walkers are configured to have four legs whose lower ends are configured to interact with the ground surface. As shown in  FIG. 1A , one such convention walker includes wheels  44  on two legs, and feet  42  on the other two legs. Other embodiments exist where all four legs have wheels  44  on their lower ends, or all four legs have feet  42  on their lower ends. 
         [0068]    Preferably, the retractable gripping device according to the present invention may be employed in the legs of a conventional walker that employs feet on the bottom ends of at least some of its legs, as depicted in  FIGS. 4B ,  5 A-D and  6 A-D. In particular,  FIGS. 5A-B  show side views of a walker  50  employing a retractable gripping device in accordance with a preferred embodiment of the invention. Referring to  FIG. 5A , depicted is the walker  50  in accordance with an embodiment of the present invention, with the gripping device  46  deactivated and in its retracted position. As depicted more clearly in  FIG. 5C , an enlarged view of the lower end of a leg from the walker  50  shown in  FIG. 5A , a pin or screw type locking mechanism  47  is in the raised and retracted position within a bored opening. In this position, the gripping mechanism  46  ( FIGS. 5B and 5D ) is in a retracted position such that it does not extend or protrude through the bottom of tip  42 . To activate the retractable gripping device, the user of the walker  50  must push the activating knob  28  down (which may be any convenient shape or size to provide easy access to and activation of the knob) such that the locking mechanism  47  moves to the lower end of bored opening  37 . Once in that position, the user need only slide, turn or rotate knob  52  in a clockwise direction until locking mechanism  47  moves into a lower locked position within a bored opening, as depicted in  FIGS. 5B and 5D . 
         [0069]    To deactivate the gripping device  46 , the user must again push down the knob  52  and slide, turn or rotate it in a counter-clockwise direction such that a spring internal to the lower leg portion of the walker will return the gripping device  46  back to its retracted, deactivated position. As shown in  FIGS. 6A-D , when not activated, a retaining spring  64  maintains the gripping device  46  in the retracted, deactivated and upward position (see  FIG. 6A ). Also as shown, when the gripping device  46  is activated and in the extended position, the spring  64  is compressed. When the knob  52  is rotated clockwise, the spring  64  will hold the gripping device  46  in the locked and activated position. All downward pressure applied to the gripping device  46  will maintain it in the locked position in conjunction with the spring  64 . 
         [0070]    More particularly,  FIGS. 6A-C  depict the internal components of the retractable gripping device in accordance with a preferred embodiment of the invention. In particular, gripping device preferably comprises knob, lever, pin or handle  52 , rod or stem  58 , locking mechanism  48 , gripping surface or mechanism  46 , and foot  42 . Of course, in this embodiment, the legs of walker  50  would preferably contain bored openings  56  and  60  for the control knob  52  and locking mechanism  48 , respectively, to pass through to the rod  58  that is positioned longitudinally within the legs of walker  50 . Optionally, a spring  64 , and bushings  54  and  62  may be employed. Spring  64  may optionally be positioned below the locking mechanism  48  such that the spring  64  would exert an upward force on the rod  58  to maintain the gripping device  46  in either the activated or deactivated position depending on the position of control knob, lever, pin or handle  52  and locking mechanism  48 . Alternatively, the spring  64  may be located near control knob, lever, pin or handle  52 . In this configuration, spring  64  would similarly exert an upward force on the rod  58  at or near the control knob, lever, pin or handle  52  to maintain the gripping device in either the activated or deactivated position depending on the position of control knob, lever, pin or handle  52  and locking mechanism  48 . Also, in an alternative embodiment of the invention, rod  58  and gripping mechanism  46  may be constructed as a single integrated component. 
         [0071]      FIG. 7A  shows an exposed front plan view of an alternative embodiment of the walking crutch  12  shown in  FIG. 1B  having a retractable gripping device  76  depicted in the retracted or deactivated position.  FIG. 7A  further shows the internal components of the retractable gripping device  76  in accordance with the alternative embodiment of the invention.  FIG. 7B  shows an exposed front plan view of the walking crutch  12  shown in  FIG. 7A  having a retractable gripping device  76  depicted in the extended or activated position.  FIG. 7B  further shows the internal components of the retractable gripping device  76  in accordance with the alternative embodiment of the invention.  FIG. 7C  shows an enlarged view of the upper end of the retractable gripping device shown in  FIG. 7B , and  FIG. 7D  shows an enlarged view of the lower end of the retractable gripping device shown in  FIG. 7B . As depicted in  FIGS. 7A-D , gripping device  76  preferably comprises knob or handle  72 , shaft or tube  76  having openings at either end, rod or tube  73 , locking mechanism  75 , gripping surface or mechanism  22 , and foot  20 . Optionally, a spring  34 , and bushing  74  may be employed. Spring  34  may optionally be positioned below the locking mechanism  75  such that the spring  34  would exert an upward force on the rod  32  to maintain the gripping device  76  in either the activated or deactivated position depending on the position of control knob  72  and locking mechanism  75 . Alternatively, the spring may be located at or near the top of gripping device  76 . Similarly, spring  34  would exert an upward force on the rod  73  at or near the control knob  72  to maintain the gripping device  76  in either the activated or deactivated position depending on the position of control knob  72  and locking mechanism  75 . Also, in an alternative embodiment of the invention, rod  73  and gripping mechanism  22  may be constructed as a single integrated component, unlike the two separate components as in the preferred embodiment. 
         [0072]    More specifically, looking at  FIG. 7B , depicted is the crutch  12  shown in  FIG. 1B , with the gripping device  76  activated and in its extended position. As depicted more clearly in  FIG. 2D , which shows an enlarged view of the lower end of the walking crutch  12  shown in  FIG. 2B , gripping mechanism  22  is in the activated and in its extended position protruding through the bottom of tip  20 . To activate the gripping device  76 , the user must push down the knob  72  thereby forcing end  75  downward such that compressed gas or air or fluid within space  78  near the lower end of gripping device  76  forces gripping mechanism  22  downward through the bottom of tip  20 . Optionally, gripping device  76  has a locking mechanism  75  to retain gripping device  76  in the activated position until such time as the user wishes to deactivate gripping device  76 . Preferably, locking mechanism  75  is a pen-click type of locking device whereby a first compression of knob  72  locks gripping device  76  in the activated position, and a second compression of knob  72  releases the gripping mechanism  22  such that gripping device is back in the deactivated position. 
         [0073]    As shown in  FIG. 7A , when not activated a retaining spring  34  maintains the gripping device  76  in the retracted, deactivated upward position. As shown in  FIGS. 7B-D , when the gripping device  76  is activated in the extended position, the spring  34  is compressed. When the knob  72  has been depressed a first time, the spring  34  and locking mechanism  75  will hold the gripping device  76  in the locked and activated position. All downward pressure applied to the gripping device  76  will maintain it in the locked position in conjunction with the spring  34 . 
         [0074]    As shown in  FIGS. 7A-D , the retractable gripping device  76  is preferably configured as a pen-click retractable locking system. As described above in greater detail, the pen-click retractable gripping device preferably comprises at least a pair of springs that allow the gripping device  22  to retract. The first spring (ratchet spring) is preferably located inside the bottom portion of tube  76  of the gripping mechanism (i.e., where the gripping device  22  comes out). The rod  73  is positioned through this first spring before going through the open end of the tube  76 . At the upper end of gripping mechanism  76 , a second spring may be positioned inside of upper end of the tube  76 . This second spring (i.e., a knob spring) may be connected to a screw and a clip, which are then connected to the knob  72  at the end of the pen. When knob  72  is depressed a first time, it presses down on the knob spring, which then forces the rod or inner tube  73  downward and out through the bottom end of gripping mechanism  76  such that it is in the activated position. A locking mechanism  75  consisting of tiny pits and teeth interlock with each other to keep the gripping mechanism  76  in its activated position. When knob  72  is depressed a second time, it again presses down on the knob spring, which then forces the rod or inner tube  73  downward and out through the bottom end of gripping mechanism  76  such that the tiny pits and teeth unlock and the rod or tube  73  and gripping device  22  are sprung back inside tube  76  by the ratchet spring such that it is in the deactivated position. 
         [0075]    Turning next to  FIG. 8A , shown is an exposed partial side view of an alternative embodiment of the walker leg shown in  FIG. 4B  having a retractable gripping device  83  with the retractable gripping device in the retracted or deactivated position, and further shows the internal components of the retractable gripping device in accordance with the alternative embodiment of the invention.  FIG. 8B  shows an exposed partial side view of the walker shown in  FIG. 8A  having a retractable gripping device with the retractable gripping device in the extended or activated position, and further shows the internal components of the retractable gripping device in accordance with the alternative embodiment of the invention.  FIG. 8C  shows an enlarged view of the upper end of the retractable gripping device shown in  FIG. 8B , while  FIG. 8D  shows an enlarged view of the lower end of the retractable gripping device shown in  FIG. 8B . 
         [0076]    In particular,  FIGS. 8A-D  depict another type of walking assistance device for which the present invention may be used.  FIG. 8A  depicts a leg of a conventional walker such as the one shown in  FIGS. 4-5 , which consists of a series of interconnected tubes, bars, pipes or rods to form a frame that a user can easily and safely use to support a good portion of his/her weight while attempting to walk around. Typically, such conventional walkers are configured to have four legs whose lower ends are configured to interact with the ground surface. As shown in  FIG. 4A , one such convention walker includes wheels  44  on two legs, and feet  42  on the other two legs. Other embodiments exist where all four legs have wheels  44  on their lower ends, or all four legs have feet  42  on their lower ends. 
         [0077]    Preferably, the retractable gripping device according to the present invention may be employed in the legs of a conventional walker that employs feet on the bottom ends of at least some of its legs, as depicted in  FIGS. 8A-D . In particular,  FIGS. 8A-B  show side views of one leg of a walker employing a retractable gripping device in accordance with an alternative embodiment of the invention. Referring to  FIG. 8A , shown is the gripping device deactivated and in its retracted position. Referring to  FIG. 8B , shown is the gripping device activated and in its extended position. As depicted more clearly in  FIGS. 8C-D , an enlarged view of the upper and lower ends of the leg shown in  FIG. 8A . In particular, shown is the retractable gripping device configured as a pen-click retractable locking system. As described above in greater detail, the pen-click retractable gripping device preferably comprises at least a pair of springs that allow the gripping device  46  to retract. The first spring (ratchet spring) is preferably located inside the bottom portion of tube  84  of the gripping mechanism (i.e., where the gripping device  46  comes out). The rod  83  is positioned through this first spring before going through the open end of the tube  84 . At the upper end of gripping mechanism, a second spring may be positioned inside of upper end of the tube. This second spring (i.e., a knob spring) may be connected to a screw and a clip, which are then connected to the knob  82  at the end of the pen. When knob  82  is depressed a first time, it presses down on the knob spring, which then forces the rod or inner tube  83  downward and out through the bottom end of gripping mechanism such that it is in the activated position. A locking mechanism  85  consisting of tiny pits and teeth interlock with each other to keep the gripping mechanism in its activated position. When knob  82  is depressed a second time, it again presses down on the knob spring, which then forces the rod or inner tube  83  downward and out through the bottom end of gripping mechanism such that the tiny pits and teeth unlock and the rod or tube  83  and gripping device  46  are sprung back inside tube  84  by the ratchet spring such that it is in the deactivated position. 
         [0078]    To activate the retractable gripping device, the user of the walker  80  must push the activating knob  82  down (which may be any convenient shape or size to provide easy access to and activation of the knob) such that the locking mechanism  88  rotates into a first locking position such that gripping device  46  is in the activated position. To deactivate the gripping device  46 , the user must again push down the knob  82  such that the locking mechanism  88  rotates into a second locking position such that gripping device  46  is in the retracted, deactivated position. As shown in  FIG. 8A , when not activated, a retaining spring maintains the gripping device  46  in the retracted, deactivated and upward position. Also as shown, when the gripping device  46  is activated and in the extended position, the spring is compressed. When the knob  82  is again depressed, the spring will hold the gripping device  46  in the locked and activated position. All downward pressure applied to the gripping device  46  will maintain it in the locked position in conjunction with the springs. 
         [0079]    More particularly,  FIGS. 8A-C  depict the internal components of the retractable gripping device in accordance with an alternative embodiment of the invention. In particular, the gripping device preferably comprises knob  82 , rod or stem  83 , spring  34 , locking mechanism  88 , gripping surface or mechanism  46 , and foot  20 . Of course, in this embodiment, the legs of walker  80  would preferably contain locking mechanism  88 , respectively, to pass through to the rod  83  that is positioned longitudinally within the legs of walker  80 . Optionally, a spring and bushings may be employed. The spring may optionally be positioned below or above the locking mechanism  88  such that the spring would exert an upward force on the rod  83  to maintain the gripping device  46  in either the activated or deactivated position depending on the position of control knob and locking mechanism  88 . Alternatively, the spring may be located near control knob  82 . In this configuration, the spring would similarly exert an upward force on the rod  83  at or near the control knob  82  to maintain the gripping device in either the activated or deactivated position depending on the position of control knob and locking mechanism  88 . Also, in an alternative embodiment of the invention, rod  83  and gripping mechanism  46  may be constructed as a single integrated component. 
         [0080]    Referring next to  FIGS. 9A-D , shown is an exposed front plan view of a second alternative embodiment of the walking crutch shown in  FIG. 1B  having a retractable gripping device with the retractable gripping device in the retracted or deactivated position (see  FIG. 9A ), showing the internal components of the retractable gripping device in accordance with the second alternative embodiment of the invention, as well as with the retractable gripping device in the extended or activated position (see  FIGS. 9B-D ). In particular, depicted in  FIGS. 9B-D  is the crutch  12  shown with the gripping device  22  activated and in its extended position. As depicted more clearly in  FIG. 9D , an enlarged view of the lower end of the walking crutch  12  showing gripping device  22  is in the activated and in its extended position within bored opening  36  such that gripping mechanism or surface  22  is protruding through the bottom of tip  20 . Preferably, this second alternative embodiment of the gripping mechanism comprises knob  90 , fluid chamber  92 , connector  96 , stem or tube  93 , bushings  94  and  98 , spring  96 , compression chamber  95 , and gripping device  22 . 
         [0081]    To activate the gripping device  22 , the user must in one embodiment repeatedly press on knob  90  such that gas or other fluid is forced from chamber  92  through stem or tube  93  into compression chamber  95  thereby exerting a downward force on bushing  98  sufficient enough to compress spring  96  and move gripping device downward through bore  36  in bottom of tip  20 . Alternatively, the forcing of gas or other fluid from chamber  92  through stem  93  into chamber  95  may be controlled by continued rotation of knob  90  until sufficient gas or fluid has entered chamber  95  to force gripping device through the bottom of tip  20 . Preferably, bushing  94  is fixed in position with lateral seal within the tube of the gripping mechanism, while bushing  98  is preferably moveable laterally within the tube but also with lateral seal such that the fluid or gas may not escape. 
         [0082]    To deactivate the gripping device  22 , the user must again push down and hold the knob  90  to release the fluid or gas from chamber  95  such that the downward force exerted on gripping device  22  reduces such that the upward force exerted by spring  96  is greater than the downward force exerted by the gas or fluid in chamber  95  and to retract gripping device  22  and return the gripping device  22  back to its retracted, deactivated position. As shown in  FIG. 9A , when not activated a retaining spring  96  maintains the gripping device  22  in the retracted, deactivated upward position. As shown in  FIGS. 9B-D , when the gripping device  22  is activated in the extended position, the spring  96  is compressed. All downward pressure applied to the gripping device  22  by the gas or fluid in chamber  95  will maintain gripping device  22  in a locked position in conjunction with the spring  96 . 
         [0083]    Referring next to  FIGS. 10A-D  and  11 , shown are whole ( FIG. 11 ) and partial ( FIGS. 10A-D ) exposed side view of an alternative embodiment of the gripping mechanism for use with a walker like the one shown in  FIG. 5A  having a second alternative embodiment of the retractable gripping device similar to the one depicted in  FIGS. 9A-D .  FIG. 10A  shows the retractable gripping device in the retracted or deactivated position, while  FIGS. 10B-D  shows a partial exposed side view of the retractable gripping device with the retractable gripping device in the extended or activated position. As depicted more clearly in  FIG. 10D , an enlarged view of the lower end of the walker  100  showing gripping device  46  in the activated and in its extended position within bored opening  66  such that gripping device or surface  46  is protruding through the bottom of tip  20 . Preferably, this second alternative embodiment of the gripping mechanism comprises knob  102 , fluid chamber  103 , connector  104 , stem or tube  105 , bushings  106  and  109 , spring  108 , compression chamber  107 , and gripping device  46 . 
         [0084]    Similar to the embodiment shown in  FIGS. 9A-D , to activate the gripping device  46 , the user must in one embodiment repeatedly press on knob  102  such that gas or other fluid is forced from chamber  103  through stem or tube  105  into compression chamber  107  thereby exerting a downward force on bushing  109  sufficient enough to compress spring  108  and move gripping device downward through bore  66  in bottom of tip  20 . Alternatively, the forcing of gas or other fluid from chamber  103  through stem  105  into chamber  107  may be controlled by continued rotation of knob  102  until sufficient gas or fluid has entered chamber  107  to force gripping device  46  through the bottom of tip  20 . Preferably, bushing  106  is fixed in position with lateral seal within the tube of the gripping mechanism, while bushing  109  is preferably moveable laterally within the tube but also with lateral seal such that the fluid or gas may not escape. 
         [0085]    To deactivate the gripping device  46 , the user must again push down and hold the knob  102  to release the fluid or gas from chamber  107  such that the downward force exerted on gripping device  46  reduces such that the upward force exerted by spring  108  is greater than the downward force exerted by the gas or fluid in chamber  107  and to retract gripping device  46  and return the gripping device  46  back to its retracted, deactivated position. As shown in  FIG. 10A , when not activated a retaining spring  108  maintains the gripping device  46  in the retracted, deactivated upward position. As shown in  FIGS. 9B-D , when the gripping device  46  is activated in the extended position, the spring  108  is compressed. All downward pressure applied to the gripping device  46  by the gas or fluid in chamber  108  will maintain gripping device  46  in a locked position in conjunction with the spring  108 . 
         [0086]    The following provides an exemplary list of various parts used in accordance with a preferred embodiment of the present invention. As will be appreciated by those skilled in the art from the foregoing, other similar parts may be used to with the present invention without diverting from the spirit and function of the present invention. Part  28  is preferably a knurled activating knob, but other types of knobs or handles may be used. Part  32  is the center rod or shaft connecting the activating knob to the gripping mechanism. Part  30  is preferably a press fit bushing which supports and centers the upper end of the center rod or shaft. Part  26  is the extended lower shaft housing for the retractable gripping device. Part  38  is a bushing that is fastened to the center rod, preferably by a screw. In a preferred embodiment of the invention, the head of the fastening screw protrudes through the wall of lower shaft housing and rides within the locking slot  37  machined into the housing. Part  34  is a spring automatically returns the gripping mechanism to its retracted position when the control or activating knob is pushed down and turned counter-clockwise. Then spring will then hold the gripping device in the upward, retracted position, ready for reactivation when needed by the user. When the control or activating knob is pushed down and turned clockwise, the spring holds the gripping mechanism in the activated or extended position. Part  20  is a rubber foot on the bottom end of lower shaft housing  26  and is maintained in position by Part  36 . Preferably, this foot has a clearance hole in its bottom center position to allow the gripping mechanism to protrude therethough when in its activated or extended position. Part  36  is a guide bushing which guides the gripping device and is press fit into the lower end of lower shaft housing  26 . The bushing also locks the rubber foot in position at the lower end of lower shaft housing  26 . Part  22  is the gripping mechanism which is attached to the center rod or shaft on its lower end and is accurately guided through the rubber foot by the guide bushing. 
         [0087]    It will be recognized by those of skill in the art that the above disclosure may be optionally actuated by a number of mechanisms without departing from the scope and spirit of the present invention. For example, the use of a power source (battery), electrical wires, switch, and a motion actuator (screw drive, linear actuator etc) to operate (drive and retract) the retractable gripping apparatus is included herewith, although not depicted. Such a modification would be understood following complete study of the enclosed disclosure so as to enable modification suitable within the required structures to accomplish the goals herein. Similarly, the use of a compressed gas volume (cylinder) to drive and retract a piston connected to a retractable gripping apparatus is included herewith. Similarly any type of pneumatic and hydraulic type actuation system for operating the retractable gripping apparatus is similarly incorporated herewith. Finally, it will be recognized that any suitable means or operable system that may be incorporated in a portable support assistance device (e.g., walking device) maybe operably used to operate the proposed retractable gripping apparatus within the scope of the present invention. 
         [0088]    In the claims, means or step-plus-function clauses are intended to cover the structures described or suggested herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, for example, although a nail, a screw, and a bolt may not be structural equivalents in that a nail relies on friction between a wooden part and a cylindrical surface, a screw&#39;s helical surface positively engages the wooden part, and a bolt&#39;s head and nut compress opposite sides of a wooden part, in the environment of fastening wooden parts, a nail, a screw, and a bolt may be readily understood by those skilled in the art as equivalent structures. 
         [0089]    Having described at least one of the preferred embodiments of the present invention with reference to the accompanying drawings, it is to be understood that such embodiments are merely exemplary and that the invention is not limited to those precise embodiments, and that various changes, modifications, and adaptations may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims. The scope of the invention, therefore, shall be defined solely by the following claims. Further, it will be apparent to those of skill in the art that numerous changes may be made in such details without departing from the spirit and the principles of the invention. It should be appreciated that the present invention is capable of being embodied in other forms without departing from its essential characteristics.