Frame for various cycles

Claim 1

A bicycle frame formed by a plurality of elements integral with each other to form a structurally continuous and homogeneous, unitary structure without inhomogeneous joints including welds, said elements including a top crossbar, a steering tube at the front end of said crossbar, a transverse crank gear case below and spaced downwardly from said crossbar, a bottom member extending from said steering tube to said crank gear case, a wheel receiving fork having two arms extending rearwardly from said crank gear case and having wheel spindle receiving openings at the rearward ends of said arms, a pair of struts extending from said arms of said fork, adjacent said openings, to the opposite, rear end of said crossbar and a rigid strut member extending from said struts at portions thereof intermediate said top crossbar and said openings to said arms of said fork adjacent said crank gear case, said crossbar, said bottom member, said two arms, said struts and said strut member each having an open cross-section which has at least one open side, said crossbar and said bottom member lying substantially in a plane, each of said crossbar, said bottom member, said two arms and said struts being disposed with said open side thereof facing away from said plane, and said strut member having a portion which extends from adjacent said crank gear case to a portion of said struts spaced from said rear end of said crossbar, having a partition extending transversely to said plane and from intermediate the ends of said portion of said strut member to adjacent said rear end of said crossbar and having a strengthening member intermediate and joined to said partition and said last-mentioned portion whereby said strut member acts as a stiffening member between said struts, and said arms to prevent movement of the upper ends of said struts toward said crank gear case.