Patents by Inventor Chang H. Ra

Chang H. Ra 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).

  • Safety lamp with noctilucent lens holder
    Patent number: 4481560
    Abstract: A lamp, particularly a miner's safety lamp, is provided with a noctilucent lens holder so that in the event of an accident causing non functioning of the normal light source of the lamp, the lens holder will provide luminous light.
    Type: Grant
    Filed: July 29, 1982
    Date of Patent: November 6, 1984
    Assignee: Nambang Corporation
    Inventor: Chang H. Ra