×

Door annunciator

  • US 4,843,374 A
  • Filed: 03/30/1988
  • Issued: 06/27/1989
  • Est. Priority Date: 03/30/1988
  • Status: Expired due to Fees
First Claim
Patent Images

1. A door annunciator comprising:

  • alarm means responsive to an energizing input signal to provide a perceptible alarm signal;

    energizing means operable to provide an energizing input signal to the alarm means for a limited interval of time;

    a battery; and

    switch means operative to couple the battery to the energizing means upon location of a door in an open position with respect to the switch means and to decouple the battery from the energizing means upon location of the door in a closed position whereby the alarm means provides the alarm signal upon opening of the door but not upon closing thereof and whereby there is no energy drainage from the battery in the closed position of the door.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×