Patents Assigned to Robert Barr
  • Patent number: 4920333
    Abstract: An alarm system for monitoring an entrance/exit from a premises is provided with a deadbolt switch, timing mechanism, alarm circuitry and an alarm indicator. The alarm system is activated when the deadbolt is unlocked. The alarm circuitry determines if the unlocking of the deadbolt was authorized or unauthorized. If the unlocking was unauthorized, the alarm indicator is activated. If the unlocking was authorized, the timing mechanism is activated. If the deadbolt is not relocked within the time period preset into the timing mechanism, the alarm indicator is activated. The timing mechanism may be reset by authorized persons to allow the deadbolt to remain open for additional time periods, one period at a time.
    Type: Grant
    Filed: May 26, 1988
    Date of Patent: April 24, 1990
    Assignee: Robert Barr
    Inventors: Robert Barr, Joel A. Fletcher