One of Perguia’s famous heel inventions was disclosed in US2795866, titled Ladies’ shoes, granted in 1956, and assigned to Isaac Miller. This heel patent concerned a replaceable heel. The invention addressed the fashion-conscious need to change heels to match an outfit, or the need for comfort to better suit a particular purpose, such as "hike or walk”.
The embodiment of the invention included a curved metal “tenon” and “mortise” slide, attached lengthwise on the outside of the shoe, under the arched and heel portions. The tenon served in this manner as a shank, and it was re-inforced by the metal mortise slide, attached to the shoe. A locking mechanism was also provided for the tenon and mortise system, in view of preventing the heel from slipping. Most importantly, the heel assembly system was designed so as to require no tools and no exertion when changing heels.
Patent figure drawings are included to the right, and below, a modern marketed version of the replaceable heel shoe.