Massachusetts Institute of Technology

Bruce M Kramer

Nathan H Cook

David M Dombrowski

Dennis Gonseth

Stephen P Kohler

Minyang Yang

a foldable shoe, comprising: a sole extending between a toe end and heel end, the sole comprising a toeroom region proximate the toe end and a heel region proximate the heel end and a midfoot region defined between the toeroom region and heel region, the toeroom region comprising a strap spanning the width of the shoe in a toe-lever region of the toeroom region, the heel region comprising at least one strap retainment recess, configured to alternately: receive the strap and retain the strap against slipping off of the sole and mitigate stress concentrations against breakage under the tensile strength of the strap and bending strength of the sole, when the shoe is folded; and define the compression strength of the sole in the heel region, such that the shoe is configured to alternately: receive a foot of a user with a ball of the user's foot retained in the midfoot region with a stretchable upper portion of the shoe that is independent of the strap; and fold into a retainment orientation, with the heel region retained in a parallel offset orientation to the toeroom region with the strap, with the upper portion contained between the toeroom region of the sole and the heel region of the sole, with the strap traversing under the sole in the heel region and retained in the strap retainment recess.

Foldable shoe

A consolidated metal-ceramic composite comprises a first phase of particles of aluminum oxide or a solid solution based on aluminum oxide uniformly distributed in a second matrix phase wherein the second matrix phase is non-reactive with aluminum oxide and contains a sufficient amount of titanium carbide at the interface between the first and second phase to prevent a chemical reaction at the interface during consolidation at the liquidus temperature and which exhibits good mechanical properties with regard to strength and toughness at high temperatures up to about 1200.degree. C.

Aluminum oxide-metal compositions

Tungsten carbide tools are provided having improved wear properties which tools produce an improved surface finish on workpieces cut with said tools, both initially and after extended use. The tools are prepared by a process which comprises applying a coating of a Group IVB or VB metal of the Periodic Chart of the Elements over the tool, diffusing said metal into the tool and removing any excess of the metal from the surface of the tool, possibly by further diffusion of the metal into the tool. The preferred method is by gaseous decomposition of a metal halide in an atmosphere which does not contain a carbon source such as methane, used in some previous processes. The source of the carbon in the Group IVB or VB metal carbide is the carbon in the carbide tool being coated. Tools formed in accordance with the invention have wear properties such that they typically last at least four times as long as untreated tools and under most preferred conditions, as much as nine times as long as untreated tools.

Growing community of inventors

Wantagh, NY, United States of America

Bruce M Kramer