Abstract:
This invention provides a device for increasing the apparent height of persons, such as may be called for in theatrical and cinematographic applications. The device enables active normal-appearing walking and other motion, and is sufficiently compact to be used under costumes, and sufficiently light to enable extended use.

Description:
This application claims benefit of Provisional Application 61/135,147, filed Jul. 16, 2008. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     This invention relates to leg extensions to increase the apparent height of persons. 
     BACKGROUND 
     Leg extensions are in common use to increase a person&#39;s apparent height, or to enable a person to perform activities that would be beyond his or her reach in the absence of such devices. Leg extensions are frequently used by plasterers, dry-wall installers, electricians, and other craftsmen to facilitate working at positions above their reach, and many such devices are described in the patent literature; for example U.S. Pat. No. 7,258,652 to Florio et al, U.S. Pat. No. 6,648,803 to Jay, U.S. Pat. No. 5,498,220 to Ensmenger, U.S. Pat. No. 5,645,515 to Armstrong et al, U.S. Pat. No. 5,514,054 to Rowan, and U.S. Pat. No. 4,927,137 to Speer, all of which teach leg extensions suitable for craftsmen. 
     Leg extensions are also employed for amusement and physical conditioning; see for example U.S. Pat. No. 6,719,671 to Böck, and similar devices distributed by Getjumpingstilts.com LLC of Elyria, Ohio. 
     Leg extensions are also employed in theatrical and cinematographic applications, to enhance the apparent height of actors or to enable special effects. A particularly effective application of leg extensions may be seen in the werewolf character in the Sony/Lakeshore Entertainment film “Underworld”. 
     For such theatrical and cinematographic applications, the leg extension device must enable active normal-appearing walking and other motion, and be sufficiently compact to be used under costumes, and be sufficient light to enable extended use. None of the devices taught in the patents referenced above or other patents found in the patent literature, or commercially available are considered suitable for such theatrical and cinematographic applications. 
     OBJECTIVES AND SUMMARY OF THE INVENTION 
     It is an objective of the present invention to provide leg extensions suitable for theatrical and cinematographic applications. 
     It is a further objective of the present invention to provide leg extensions that will allow actors to employ their full range of motions. 
     It is a further objective of the present invention to provide leg extensions that are sufficiently light in weight to enable extended use by actors without excessive fatigue. 
     It is a further objective of the present invention to provide leg extensions that will allow actors to walk with an apparently normal gait. 
     It is a further objective of the present invention to provide leg extensions that can be concealed under a costume. 
     The present invention achieves these objectives by providing compact leg extension devices comprising thigh- and calf-mounting assemblies pivotally connected at about the level of the user&#39;s knee and pivotally attached at about the level of the user&#39;s ankle to foot-mounting assemblies, with compact extension members connected to said foot-mounting assemblies and aligned approximately along the axis of the user&#39;s foot. Cables are attached between the foot-mounting assemblies and the thigh-mounting assemblies, to assist in bearing the user&#39;s weight on said extension members. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective drawing of the leg extension of the present invention. 
         FIG. 2  shows the leg extension of the present invention as attached to a user. 
         FIG. 3  shows details of the foot leveling adjustment mechanism of the leg extension of the present invention. 
         FIG. 4  shows details of the length-adjustment mechanism of the cable assembly of the leg extension of the present invention. 
         FIG. 5  shows details of a more preferred alternate embodiment of the foot assembly of the leg extension of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention taught and claimed in the present patent application comprises: a) a thigh assembly, removeably attachable to the user&#39;s thigh and pivotably attached at its lower end to b) a calf assembly, removeably attachable to the user&#39;s calf, which assembly is pivotably connected at its lower end to c) a foot assembly, which is removeably attachable to the user&#39;s foot and comprises an extension extending forward from the user&#39;s foot and terminating in a ground-contacting shoe or toe-piece, said extension having the effect of elevating the users foot above the ground or floor and increasing said user&#39;s apparent height; and d) a cable assembly which is attached at its lower end to the foot assembly and attached at its upper ends to the thigh assembly. 
     In a preferred embodiment, shown at  10  in  FIGS. 1 and 2 , thigh assemblies  20  comprise rigid inner and outer thigh bars  21 , and thigh half-cuffs  22  bridging said inner and outer thigh bars and attached thereto, and adapted to detachably engage the front of the user&#39;s thighs. Said thigh half-cuffs are equipped with disconnectably connectable thigh straps  23 , said half-cuffs and said thigh straps adapted to enclose and attach securely to the user&#39;s thighs such that the inner and outer rigid thigh bars are situated on the medial and lateral surfaces, respectively, of the user&#39;s thighs and approximately parallel to the long axis of the user&#39;s thighs. 
     In said preferred embodiment, said thigh half-cuffs will comprise slots  27  near each side margin of said half-cuffs. Said thigh straps are permanently connected to said slots of said thigh half-cuffs on a first side of said thigh half-cuffs, and are adapted to be passed around the back of the user&#39;s thigh and be removeably and adjustably attached to slots in a second side side of said thigh half-cuffs. Preferably, said thigh straps may comprise webbing equipped with connection means  28  such as “Velcro” or similar hook and loop connection means, and/or web buckles of any the suitable types which are well known in the art. Said thigh straps are adapted to be passed through said slots in said second side of said thigh half-cuffs, pulled through said slots to tighten said straps sufficiently to attach said thigh assembly securely to the user&#39;s thigh, and be looped back upon and fastened to themselves by said connection means. 
     Said thigh half-cuffs  22  may be attached to said thigh bars  21  by bolts, rivets, or any of the convenient fastening means well known in the art. In a preferred embodiment, said thigh half-cuffs will comprise a plurality of attachment holes  24  spaced apart along an axis approximately parallel to the long axis of the half-cuff, and said thigh bars  21  will also comprise a plurality of attachment holes  25  spaced apart along the long axis of said thigh bars  21 . In said preferred embodiment, said thigh bars  21  will be attached to said thigh half-cuffs by means of a clevis pin with cotter pin passing through one of said thigh bar attachment holes and one of said thigh half-cuff attachment holes. The plurality of attachment holes on said thigh bar and on said thigh half-cuff will allow adjustment for optimum fitting to users of differing leg length. 
     In a more preferred embodiment, said thigh bars  21  may comprise steel bars approximately ⅛″×¾″ in cross section; said thigh half-cuffs  22  may be ABS approximately ¼″ thick, shaped to fit snugly against the front of the user&#39;s thighs, such that in cooperation with said disconnectably connectable straps  23 , they may enclose a portion of the user&#39;s thigh and be securely and disconnectably attached thereto. In said more preferred embodiment, the upper end of said thigh bars  21  will comprise a forward-curved section, as shown in  FIG. 1 ; this forward curvature, together with the plurality of attachment holes in said thigh half-cuff and the plurality of attachment holes in said thigh bars is found to facilitate adjustment to different size users. 
     Said preferred embodiment shown at  10  will also comprise calf assemblies  30  comprising rigid inner and outer calf bars  31 , calf half-cuffs  32  bridging said inner and outer calf bars, and calf straps  33 . Said calf half-cuffs  32  are adapted to engage the back of the user&#39;s calf, and cooperate with said calf straps  33 , said thigh assemblies  20  and foot assemblies  40 , to be described below, to position said calf bars along the medial and lateral surface of the user&#39;s calves and approximately parallel to the long axis of the user&#39;s calves. 
     Said calf half-cuffs  32  of said calf assemblies  30  of said preferred embodiment  10  will extend in a forward direction beyond their attachment to said calf-bars  31 , as shown in  FIG. 1 , and will comprise a plurality of slots  34  close to the edges of said calf half-cuffs. Said calf straps  33  are permanently connected to slots on a first side of said calf half-cuffs  32 , as by looping each of said straps through one of said slots and attaching to itself by staples, rivets or other means of attachment such as are well known in the art. The free ends of said straps  33  are adapted to be passed around the front of the user&#39;s calf and be removeably and adjustably attached to slots in a second side of said thigh half-cuffs. Preferably, said calf straps may comprise webbing equipped with connection means  35  such as “Velcro” or similar hook and loop connection means, and/or web buckles of any the suitable types which are well known in the art. Said calf straps may be passed through said slots in said second side of said calf half-cuffs, pulled through said slots to tighten said straps sufficiently to attach said calf assembly securely to the user&#39;s calf; and be looped back upon and fastened to themselves by said connection means. 
     In a more preferred embodiment, said calf bars  31  may comprise steel bars approximately ⅛″×¾″ in cross section; said calf half-cuffs  32  may be ABS approximately ¼″ thick, shaped to fit snugly against the back of the user&#39;s calves, such that in cooperation with said disconnectably connectable straps  33 , they may enclose a portion of the user&#39;s calf and be securely and disconnectably attached thereto. 
     In said preferred embodiment shown at  10 , said thigh bars  21  are pivotably connected at their lower end to the upper end of said calf bars  31 . In a more preferred embodiment, said pivotable connection will comprise calf bar stabilizing plates  36 , as illustrated in  FIG. 1 , attached to the forward edge of said calf bars  31  by welding, brazing or any of the attachment means well known in the art. Each of said thigh bars  21  is pivotably enclosed between said calf bars  31  and said calf bar stabilizing plates  36 . Said stabilizing plates will minimize any twisting or torqueing of thigh bars  21  with respect to calf bars  31 , and also limit the pivoting forward excursion of thigh bars  21  with respect to calf bars  31  to a position approximately colinear with said calf bars, which serves to minimize the danger of hyperextension of the user&#39;s knee. 
     In said preferred embodiment shown at  10  in  FIGS. 1 and 2 , calf bars  31  are pivotably connected to foot assemblies  40  at foot attachment brackets  41 , which brackets are attached to foot assemblies  40  by welding, brazing, or any of the attachment means well known in the art. Said pivotable connection between said calf bars and said foot attachment bracket may preferrably comprise foot assembly stabilizing plate  47  attached at its lower end (i.e., closest to foot plate  43 ) to said foot attachment bracket  41  by welding, brazing or any of the attachment means well known in the art. Said foot assembly stabilizing plate  47  will minimize any twisting or torqueing of calf bars  31  with respect to said foot attachment bracket  41 . 
     In said preferred embodiment shown at  10  in  FIGS. 1 ,  2  and  4 , said foot assemblies  40  comprise foot attachment bracket  41 , heel bracket  42 , foot plate  43 , disconnectably connectable foot straps  44   a  and  44   b , foot bar  45 , and toe assembly  50 . Preferably, brace  46 , shown in  FIG. 4 , connects foot attachment bracket  41  to heel end of foot plate  43 . Foot attachment bracket  41  and heel bracket  42  are attached to foot plate  43  by welding, brazing, or any of the attachment means well known in the art, and foot plate  43  is similarly attached to foot bar  45 . Said foot straps  44   a  and  44   b  cooperate with said foot plate  43  to securely and disconnectably attach said foot assemblies  40  to the user&#39;s feet. Foot straps  44   a  and  44   b  will preferably comprise attachment means  48  such as “Velcro” or similar hook and loop connection means, and/or web buckles of any the suitable types, which are well known in the art. Foot straps  44   a  and  44   b  will preferably comprise loops  49 . Foot straps  44   a  and  44   b  are adapted to be pulled through loops  49  to tighten said straps sufficiently to attach foot plate  43 , and hence foot assembly  40 , securely and removably to the user&#39;s foot, then be looped back upon and fastened to themselves by said attachment means. 
     In said preferred embodiment shown at  10  in  FIGS. 1 ,  2  and  4 , said foot bars may preferably extend beyond the forward end of the user&#39;s foot a distance determined by the additional amount desired to be added to the user&#39;s height, but the leg extension of the present invention may readily be utilized to add as much as 14 or more inches to the user&#39;s apparent height. 
     In a more preferred embodiment, said foot bar  45  may comprise square cross-section 1″ steel tubing with about ⅛″ wall thickness. Said foot plates  43  may comprise a steel plate attached to said foot bars  45  by welding, brazing, or any of the attachment means well known in the art. 
     In a more preferred alternate embodiment of said foot assemblies  40 , illustrated in  FIG. 5 , foot assemblies  40  will comprise half-shoes  71 , similar to the sole and instep portion of a shoe, and adapted to partially surround and support a user&#39;s feet, wherein said half-shoes are preferably comprised of ¼″ thick ABS, and are attached to said foot bars  45  by cement, bolts, clevis pins, or other attachment means well known in the art. Said half-shoes  71  comprise a plurality of slots near the lateral and medial edge of said half-shoes through which foot straps  44   a , and  44   b , will be attached by looping each of said straps through one of said slots and attaching to itself by staples, rivets or other means of attachment such as are well known in the art. This said more preferred embodiment will comprise foot supports  72  composed of polyurethane foam known to the art “lightweight black polyurethane sponge”, and comprising ball supports  73 , which are elevated at their forward ends and are supported by cushions  74 . Said half-shoes  71 , said foot supports  72 , said ball supports  73  and said foot straps  44   a  and  44   b  are adapted to securely but removeably attach said foot assemblies  40  to the user&#39;s feet. The effect of this said more preferred embodiment, in use, is to support the users weight on the balls of the feet, and is similar to the foot position and weight distribution experienced in wearing a woman&#39;s high-heel shoe. This embodiment is found to relieve stress on the user&#39;s feet and calves, and reduce user fatigue in prolonged use. This more preferred alternate embodiment, illustrated in  FIG. 5 , will not comprise foot plates  43 , and foot attachment brackets  41 , heel brackets  42  and brace  46  will be attached to foot bars  45 , as shown in  FIG. 5 , by welding, brazing, or any of the attachment means well known in the art. Half-shoes  71  will also be attached directly to foot bars  45 . 
     In said preferred embodiment shown at  10  in  FIGS. 1 and 2 , said foot bars  45  will be attached at their lower ends to toe assemblies  50 . In a more preferred embodiment, toe assembly  50  may comprise at least one toe plate  51  attached to toe support plate  52 . Toe plates  51  will preferably be curved upward at their forward and rearward tips, and be fabricated of spring-tempered steel, with rubber or other skid-resistant material applied to or attached to its bottom surface. 
     In said more preferred embodiment, each foot bar  45  will be attached, at its lower extremity, to a leveling mechanism, illustrated in detail in  FIG. 3 , comprising leveling plate  53 , which is attached to foot bar  45  by welding, brazing, or any of the attachment means well known in the art. Leveling plate  53  will be connected to toe support plate  52  by three leveling bolts  54  approximately evenly spaced around foot bar  45 , and attached to toe support plate  42  by welding, brazing, or any of the attachment means well known in the art. Each leveling bolt will comprise nuts, beveled washers and locking nuts adapted to independently adjust the spacing between toe support plate  52  and leveling plate  53  at three approximately evenly spaced points. This three-point connection mechanism is adapted to adjust the angular alignment, in both fore-and-aft and lateral directions, between foot bar  45  and toe plate  51  to adapt to the user&#39;s requirements or preferences. 
     Said preferred embodiment shown at  10  in  FIGS. 1 and 2 , will further comprise, for each leg of a user, cable assembly  60  comprising cable having a rated breaking strength of at least about 6100 lbs (snap strength). Said cable of cable assembly  60  will be looped around thimble  61  and secured by crimped ferrule  62 . Doubled cable  63  then passes through heel bracket  42 , and both cable components are secured together by another crimped ferrule  64 , and each of the two ends  68  and  69  of the cable, which may preferably be terminated with swage eyes or formed into loops, is connected to each of said thigh bars  21  by means of bolts or rivets passing through said swage eyes or loops, or by any of the similar attachment means well known in the art 
     Thimble  61  will be connected to shackle bolt  65  by a bolt, clevis pin or similar means well known in the art. The threaded part of shackle bolt  65  is passed thru a clearance hole in cable attachment bracket  66 , which is attached to foot bar  45  by welding, brazing, or other attachment means known in the art, and is equipped with a nut and lock nut  67 . Said nut and locking nut  67  may be adjusted on shackle bolt  65  to effectively shorten or lengthen cable assembly  60  to adapt to the user&#39;s requirements or preferences. 
     In use, the user places his or her foot on said foot plate  43  and fastens said foot straps  44  to securely but disconnectably fasten said foot assembly  40  to user&#39;s foot; the user may then attach thigh assembly  20  to user&#39;s thigh by securing the thigh straps  23 , and attach the calf assembly to the user&#39;s calf by securing calf straps  33 . The user can then stand up, and, with a minimum of practice, move about securely, and walk with a gait resembling a normal gait, but with an increased apparent height. Cable eye bolts  61  will be adjusted so that cables  60  will transfer part of the strain on the user&#39;s ankles caused by user&#39;s weight to the user&#39;s thighs. 
     It has been found that the user&#39;s apparent height can readily be increased by 12″ or 14″, and allow a user to quickly adapt to the devices and stand and move about with minimal effort. The devices are sufficiently compact that trousers or other costumes can be accommodated over them. 
     Other embodiments will be apparent to one skilled in the art, which will change various details of the present invention without limiting its scope. Furthermore, the foregoing description of the preferred embodiment of the invention and the best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation of the invention, which will be defined by the claims appended hereto.