This invention relates to stilts.
Stilts are well known and are used to increase the height of an individual and to permit the individual to walk from one position to another at an elevated level. Stilts are worn by circus clowns and other entertainers, but specialist stilts may be worn by tradesmen or fruit-pickers who have to work in areas above normal arms-reach and where it is otherwise difficult to install platforms, ladders and the like.
In their simplest form, stilts comprise a pair of elongate members, each member supporting a block which provides a platform for a foot of the user. The lower end of each member engages the ground, while the upper end serves as a hand grip. In other versions, the members are strapped to the respective lower legs of the user. Such stilts have traditionally been fabricated from wood. However, various forms of improved stilts are disclosed in my International Patent Publication No. WO91/11222. The embodiments of stilts described each have a resilient foot which considerably facilitates walking, particularly when compared with conventional, rigid stilts. In one embodiment the flexible foot is hinged to move laterally as well as back to front and this improves the stability of the stilt and facilitates running and use of the stilts in sports. The disclosed arrangement includes a foot having a flat sole and two upstanding portions which define a longitudinal channel to receive a downward projection on a lower stilt member. The downward projection carries a pivot pin which is received in vertical slots provided in the upstanding projections on the foot. Coil springs are provided at the front and rear of the foot and a shock absorbing rubber pad is also disposed between the top of the sole and the bottom of the leg projection to cushion the wearer whilst walking or running. While this arrangement has been found generally satisfactory it has been found that, on occasion, because the flat sole stays in contact with the ground, lateral movement of the stilt may cause the pivot pin to be dislodged from one of the slots when the stilt is tilted to one side. Also, the arrangement is relatively complex to manufacture.
Other forms of stilts provided with resilient feet have been proposed including those disclosed in U.S. Pat. Nos. 2,835,493 and 4,927,137 to R. P. Skaggs et al and Speer, respectively. Skaggs et al disclose a foot arrangement somewhat similar to my own arrangement as described above, but without the provision of a shock absorber, and Speer provides a clevis on the lower leg portion of the stilt which is attached, by means of a pivot pin, to an upstanding rib on a foot plate. Further, Speer and Skaggs differ somewhat from my prior proposal in that the foot plates are not capable of pivoting about a front to back, or longitudinal axis.
Further, while existing stilt designs may be adequate for simple walking, when slits have been used during sports, acrobatics or in performance arts difficulties have been encountered due to the increased forces which the stilts must bear. In traditional stilt design, the upper stilt member which extends upwardly from the foot support platform is strapped to the outside of the calf of the user. Thus, the calf strap is subject to twisting forces or torques which may be uncomfortable to the user. Also, with this arrangement it is difficult to prevent relative movement between the upper stilt member and the leg. In my WO91/11222 I disclose a number or stilt configurations in which the upper stilt member extends up the front of the leg, to also act as a shin guard, but in use it has been found that, without very heavy construction, the upper stilt member is prone to flexing in response to torques, which creates an undesirable sensation of instability for the user.
In Speer's US Patent, the upper section of the stilt includes two parallel support members for disposition on either side of the user's leg. Both members are longitudinally rigid and the outer member is also preferably laterally rigid. However, the inner member may be thinner and may be designed with some material flexibility so as to allow the inner member to conform closely to the leg. Thus, it is considered that this stilt arrangement will suffer from the disadvantages of the traditional stilt arrangements described above.
U.S, Pat. Nos. 4,570,926 and 4,449,256 to Ensmenger and Prueitt, respectively, and French Patent Document No. 2,594,344 to Champel disclose various stilt arrangements in which a member extends up each side of the leg of the wearer to a securing band. In each of these arrangements the members are pivotally mounted to the foot support such that the members will likely not resist torsion very well and thus tend to move relative to one another, producing a sensation of instability.
For use in sports and other active uses of stilts, there is also the danger that the knee, through a fall or collision, could be subject to a large force tending to hyperextend or bend the knee the `wrong` way. Such accidents occur in other sports and can result in tendon damage often requiring extensive restorative surgery and a lengthy recovery period, and a long term reduction in knee strength and flexibility.
Various embodiments of the stilts disclosed in my WO91/11222, and also Speer, include knee protecting pads, but these offer minimal protection against the type of injury described above.
It is an object of one of the aspects of the present invention to provide stilts having an improved foot configuration.
It is an object of another aspect of the present invention to provide stilts having an improved upper leg configuration.
It is an object of a still further aspect of the present invention to provide stilts having improved knee protection.