Patents Assigned to Byrne & Davidson Industries Limited
  • Monitoring circuit for a door operating D.C. electric motor
    Patent number: 4675586
    Abstract: A monitoring circuit for a door operating D.C. electric motor, the circuit comprises a first means for detecting a back EMF of the motor and producing a load signal indicative of the magnitude of the back EMF, a second means for detecting the time rate of change of the load signal and issuing an obstruction signal if the magnitude of the time rate of change of the load signal exceeds a predetermined value.
    Type: Grant
    Filed: June 5, 1985
    Date of Patent: June 23, 1987
    Assignee: Byrne & Davidson Industries Limited
    Inventors: Otto Eigner, Richard E. Jones
  • Drive means for roller door
    Patent number: 4644813
    Abstract: An improved roller door drive assembly comprising a drum, upon which a curtain is rolled, and a gear coaxially mounted to and engaged with the drum. The means of engagement consists of a plurality of forks projecting from the gear adapted to engage drum spokes. This arrangement prevents the ends of the drum while running in a swashplate manner from dragging the gear out of alignment with its driving pinion. In so doing this engagement means prevents excessive wear.
    Type: Grant
    Filed: July 24, 1984
    Date of Patent: February 24, 1987
    Assignee: Byrne & Davidson Industries Limited
    Inventors: Martin H. Whitehouse, Richard E. Jones