Patents by Inventor Wen-Kuei Chao

Wen-Kuei Chao 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: 5340224
    Abstract: A push-type writing instrument, particularly a pencil, includes a retaining collar downwardly protruded from a pair of radially opposed fingers provided on a tapered forward portion of an outer body in which a lead is retained, having two arm members with each arm member connected between the retaining collar and each finger for suspending the retainer collar under the pair of opposed fingers to prevent loss of resilience of the two fingers due to fatigue failure when frictionally holding the lead between the two fingers for a long time service.
    Type: Grant
    Filed: July 30, 1993
    Date of Patent: August 23, 1994
    Inventor: Wen-Kuei Chao
  • Patent number: 4251163
    Abstract: Knock-out type automatic pencil comprises an outer barrel, an inner tube of plastic material molded integrally with a clamp and a head, a stopper collar inside the front end of outer barrel which retains the inner tube, a press device at the rear end of the outer barrel having lead sharpening and erasing means provided. The clamp at the front end of inner tube is formed in a closed type with slots on it instead of the conventional claw type.
    Type: Grant
    Filed: March 21, 1979
    Date of Patent: February 17, 1981
    Inventor: Wen-Kuei Chao
  • Patent number: 4153379
    Abstract: Knock-out type automatic pencil comprises an outer barrel, an inner tube of plastic material molded integrally with a clamp and a head, a stopper collar inside the front end of outer barrel which retains the inner tube, a press device at the rear end of the outer barrel having lead sharpening and erasing means provided. The clamp at the front end of inner tube is formed in a closed type with slots on it instead of the conventional claw type.
    Type: Grant
    Filed: January 25, 1977
    Date of Patent: May 8, 1979
    Inventor: Wen-Kuei Chao