Patents by Inventor David J. H. Chang

David J. H. Chang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4918838
    Abstract: This is a sole with compressible shock absorbers which not only provides an improved shock absorbing function but also provides more comfort for the wearer. The shock absorbers consist of a polygonal replaceable air bellows placed in a polygonal recess on the forefoot section of the shoe and a cylindrical replaceable air cylinder placed in a circular recess on the heel section of the shoe. The air cylinder and air bellows are made of an integrally resilient air-tight material such that, during exercise, the shock absorbers absorb and then return the energy in a controlled upward direction, by way of the bellows-type body and the friction caused between the inside wall of the recess and the bellows itself. Moreover, since the shock absorbers can be placed easily by hand, the wearer can adjust the shoes in line with his weight and type of sport performed.
    Type: Grant
    Filed: August 5, 1988
    Date of Patent: April 24, 1990
    Assignee: Far East Athletics Ltd.
    Inventor: David J. H. Chang
  • Patent number: D334463
    Type: Grant
    Filed: June 22, 1988
    Date of Patent: April 6, 1993
    Assignee: Hi-Tec Sports PLC
    Inventor: David J. H. Chang