Patents Assigned to BSG (Security) Limited
  • Electromagnetic lock
    Patent number: 4439808
    Abstract: An electromagnetic lock for, for example, a door comprising an electromagnet attached to the frame and a magnetizable member attached to the door the magnetizable member being attracted to the electromagnet when the door is in its closed or otherwise locked position, shoulders being provided on or adjacent the electromagnet and magnetizable member whereby if the door is forced to overcome the electromagnetic attraction the shoulders engage to prevent unauthorized unlocking of the door.
    Type: Grant
    Filed: July 28, 1981
    Date of Patent: March 27, 1984
    Assignee: BSG (Security) Limited
    Inventor: Peter J. Gillham