Patents Assigned to NDK, Incorporated
  • Patent number: 5240514
    Abstract: In subjecting a steel workpiece to nitriding by glow discharge, formation of brittle nitrogen compound is restrained and the surface hardened layer with a nitrogen diffusion layer of high toughness is obtained by making the gas atmospheric condition the gas mixing ratio of N.sub.2 :H.sub.2 =1:2-40. By mixing Ar gas in the above gas atmospheric condition additionally, glow width is adjusted and glow discharge is allowed to enter into narrow concaves at the surface of a workpiece.
    Type: Grant
    Filed: September 30, 1991
    Date of Patent: August 31, 1993
    Assignee: NDK, Incorporated
    Inventors: Kiyomi Yasuura, Katunori Hanakawa, Yoshihisa Miwa
  • Patent number: 4506903
    Abstract: A device is disclosed for detachably coupling a wheeled oxygen tank cart to a wheelchair such that they are transportable together as a unit without the need of a separate operator of the cart. The device is adjustable in length such that various sizes of wheelchairs may be accommodated. In one embodiment, the oxygen cart rolls in tandem with the wheelchair during use of the device; in another embodiment, the oxygen cart is wholly supported on the wheelchair by the device.
    Type: Grant
    Filed: March 3, 1983
    Date of Patent: March 26, 1985
    Assignee: NDK, Incorporated
    Inventor: Sidney P. Bowermaster