Patents by Inventor Tung-Chi Cheng

Tung-Chi Cheng 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: 5974912
    Abstract: A door lock unlockable electro-magnetically and with a key consists of an inner plate, a control device, a drive mechanism, a housing, a handle and a locking mechanism. The control device has a control block engaging a post of the inner plate, and the control block has an outer end engageable with the drive mechanism. An IC key card can power the control device to unlock the door lock, and a key can also be used to rotate the locking mechanism for rotating the drive mechanism which moves inward to engage the control block of the control device. Then the handle can be rotated to rotate the shaft of a deadbolt to disengage from a deadbolt hole in a door frame to unlock the door lock for preventing from being unlocked by prying or breaking said lock mechanism illegally.
    Type: Grant
    Filed: November 13, 1998
    Date of Patent: November 2, 1999
    Inventors: Tung-Chi Cheng, Jui-Hua Chang