Abstract:
Transfemoral rotator. The transfemoral rotator includes an inner cylinder that nests within a cavity of a base shell. A spring clip mechanism operated by a push button serves to lock and unlock the transfemoral rotator to allow sitting cross-legged.

Description:
[0001]    This application claims priority to US Provisional Patent Application Ser. No. 62/287,969 filed on Jan. 28, 2016, the contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Transfemoral rotators are devices that allow above-knee amputees to sit cross-legged while wearing a prosthesis. The transfemoral rotator fits between an amputee&#39;s socket and a prosthetic knee, and allows for rotation of distal prosthetic components along a longitudinal axis. Present day transfemoral rotators in developed nations are typically made of expensive materials and can cost thousands of dollars. These devices are also extremely complex and typically include 20-50 components. 
         [0003]    The transfemoral rotator disclosed herein allows for a much simpler and lower cost design. The disclosed design has applications for the developing world by allowing for a low cost and simple structure to achieve previously unattainable rotation of a lower limb prosthesis thereby increasing quality of life for above-knee amputees. 
       SUMMARY OF THE INVENTION 
       [0004]    The transfemoral rotator according to the invention includes a base shell having a cylindrical central cavity therein and having a lower opening and further including a button-retaining recess for holding a button for movement in a peripheral location of the base shell. An inner cylinder is nested for rotation within the base shell central cavity. The inner cylinder includes a lower cylindrical hub sized to protrude through the lower opening in the base shell, the inner cylinder further including a spring clip-retaining recess for receiving a U-shaped, pushbutton, spring clip. The U-shaped spring clip has a dimple protruding through a hole in the inner cylinder and through a hole in the base shell to lock the inner cylinder with respect to the base shell. The pressing of the button will unlock the inner cylinder with respect to the base shell allowing the inner cylinder to rotate freely through 360 degrees. The base shell is also adapted to receive a top plate having a connector and wherein the lower cylindrical hub includes a connector that may be a set screw connector. 
         [0005]    In a preferred embodiment, the button includes a dimple for engaging the dimple in the U-shaped spring clip. It is preferred that the top plate include a domed portion and wherein the connector is a tapered square connector or a threaded screw connector. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0006]      FIG. 1  is an exploded, perspective view of an embodiment of the invention showing all of the parts. 
           [0007]      FIG. 2  is a perspective, cutaway view of an embodiment of the invention showing the internal mechanism in a locked state. 
           [0008]      FIG. 3  is a perspective, cutaway view of an embodiment of the invention showing the internal mechanism in an unlocked state. 
           [0009]      FIG. 4  is a perspective top view of an embodiment of the invention. 
           [0010]      FIG. 5  is a perspective bottom view of an embodiment of the invention. 
           [0011]      FIG. 6  is a perspective view of an alternative connector embodiment on the top plate. 
           [0012]      FIG. 7  is a plan view of an alternative embodiment of the invention in which the push button is hinged. 
           [0013]      FIG. 8  is a plan view of the embodiment in  FIG. 7  that has been unlocked for rotation. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0014]    With respect to  FIG. 1 , a transfemoral rotator  10  includes a base shell  12  having a central cavity  14  therein and includes a relief hole  16  in its lower portion. The base shell  12  includes an inner wall  18  forming a button cavity  20 . A push button  22  is configured to fit within the button cavity  20 . The button  22  includes a protruding button dimple  24 . 
         [0015]    A pushbutton spring clip  26  is U-shaped and includes a dimple  28 . Threaded holes  30  receives bolts  32  for securing a top plate  34  to the base shell  12 . 
         [0016]    An inner cylinder  36  is adapted to nest in the cavity  14  of the base shell  12 . A lower cylindrical hub  38  will protrude through the hole  16 . Set screws  40  are used to attach the lower cylindrical hub  38  to an external connector. It is also preferred that the top plate  34  include a domed portion  42  along with a tapered square connector  44 . 
         [0017]    With reference now to  FIGS. 2 and 3  in conjunction with  FIG. 1 , the spring clip  26  fits in a cavity  48 . The spring clip  46  urges the dimple  28  through a hole in the inner wall  18  to engage the dimple  24  on the button  22 . 
         [0018]    As shown in  FIG. 2 , the inner cylinder  36  is locked with respect to the base shell  12 . 
         [0019]    As shown in  FIG. 3 , upon pushing on the button  22  the dimple  28  is pushed out of the hole thereby unlocking the inner cylinder  36  with respect to the base shell  12  allowing the inner cylinder to rotate freely with respect to the base shell  12 . Also shown is the inner cylinder outer wall  50 . 
         [0020]    The assembled transfemoral rotator  10  disclosed herein is shown in  FIGS. 4 and 5 . Those of ordinary skill in the art will understand that the tapered square connector  44  can be used to attach to an amputee&#39;s socket or to a prosthetic device. Similarly, lower cylindrical hub  38  includes the set screws  40  for attachment to a prosthesis or to the socket of an amputee. 
         [0021]    With reference again to  FIGS. 2 and 3 , those of skill in the art will recognize that when an amputee wishes to cross a prosthesis, the button  22  is pushed to release the inner cylinder with respect to the base shell permitting up to 360 degrees of rotation, allowing the crossing of one&#39;s legs. 
         [0022]    With reference now to  FIG. 6 , an alternative embodiment includes a threaded screw connector  60  extending from the top plate  34 . The threaded screw connector  60  is adapted to attach to a prosthesis as will be appreciated by those of skill in the art. 
         [0023]    With reference now to  FIGS. 7 and 8 , the push button  22  is hinged at  62  at one end. In  FIG. 7 , the femoral rotator is in the locked position. Upon depressing the push button  22 , it will pivot about the pivot point  62  depressing the button  28  thereby releasing the femoral rotator into its unlocked position as shown in  FIG. 8 . 
         [0024]    It is recognized that modifications and variations of the present invention will be apparent to those of ordinary skill in the art and it is intended that all such modifications and be included within the scope of the appended claims.