Patent ID: 7954256

Claim:
An interchangeable footwear system, comprising: a plurality of interchangeable uppers; a plurality of interchangeable heels; and a quick-release device comprising a rigid slide reversibly fastenable to the plurality of interchangeable uppers and reversibly fastenable to the plurality of interchangeable heels for selectively engaging a heel of the plurality of interchangeable heels with an upper of the plurality of interchangeable uppers, a rigid guide to mate with the rigid slide, and a safety feature comprising a fastener, at least one complementary orifice for locking together the guide and the slide using the fastener, at least one safety element, and at least one complementary slot for accommodating the at least one safety element, wherein the fastener comprises at least one element selected from a group consisting essentially of a nail, a screw, a thumbscrew, a bolt, a pin, a pair of complementary rivets, and a dowel, wherein the safety element comprises a proximal end, an intermediate portion, and a distal end, the intermediate portion comprising a cross-sectional area being less than those of both the proximal and distal ends, wherein the safety element and the complementary slot respectively comprise at least one cross-sectional configuration selected from a group consisting essentially of an oval of Cassini, a cross-section in a plane parallel to an axis of a torus, a two-leaved lemniscate of Bernoulli, and a nephroid, and wherein the cross-sectional area of the complementary slot approximates that of the intermediate portion for facilitating a resistance-fit between the complementary slot and the intermediate portion.