Dual mode electronic intrusion or burglar alarm system

• US 4,559,527 A
• Filed: 09/29/1982
• Issued: 12/17/1985
• Est. Priority Date: 09/29/1982
• Status: Expired due to Fees

• Current Assignee: Brian T. Kirby
• Original Assignee: Brian T. Kirby
• Inventors: Kirby, Brian T.
• Primary Examiner(s): Rowland, James L.
• Assistant Examiner(s): TUMM, BRIAN
• Application Number:
  US06/428,392
• Time in Patent Office: 1,175 Days
• Field of Search: 340/501, 340/528, 340/541, 340/545
• US Class Current: 340/545.9
• CPC Class Codes: G08B 13/08 by opening, e.g. of door, of window, of drawer, of shutter, of curtain, of blind

Abstract

A dual mode electronic intrusion or burglar alarm system for use with a door or window which can be opened and closed comprises a switch actuatable by the door or window, a control circuit, including time delay circuitry, operatively connected to the switch and responsive to switch actuation to operate in either of two modes, and an alarm connected to be operated by the control circuit. When the system is in operation and armed in a first mode, initial actuation of the switch in response to opening of the door or window causes the control circuit to actuate the alarm for a first predetermined interval of time, then to shut off the alarm and arm itself in a second mode wherein subsequent actuation of the switch in response to closing of the door or window causes the control circuit to again actuate the alarm for a second predetermined interval of time. The system can be reset for operation in the first mode either during the first interval of time, or at any time thereafter, i.e., during the time it is armed in the second mode, or during the second interval of time. The system aims to trap, or at least further discourage, an intruder who observes or counts on the fact that the first actuation of the alarm fails to evoke an appropriate security response and returns to complete the intrusion and closes the door or window after entry to provide the appearance of normality.

Claims

1. In an intrusion alarm system for discouraging an intruder who observes that a first actuation for a limited time of an alarm occasioned by a first attempt at entry into secured premises fails to evoke an appropriate security response and then makes a second attempt at entry, in combination:

a plurality of components movable between open and closed positions and enabling entry into said secured premises when in open position;

a plurality of first switch means, each actuatable by movement of one of said components and having conditions corresponding to the positions of the component with which it is associated;

alarm means actuatable to provide a warning signal indicative of movement of any one of said components and observable by an intruder;

and control means, including timer means operatively connected to said plurality of said first switch means and to said alarm means and operable when any one of said first switch means is actuated from one condition to another condition to actuate said alarm for a first predetermined interval of time normally sufficient to evoke a security response, and further operable after termination of said first predetermined interval of time to again actuate said alarm for a second predetermined interval of time when said one of said first switch means is actuated from said other condition to said one condition,

said control means further including;

second switch means selectively actuatable by a non-intruder to arm said system and enable it to operate said alarm and to disarm said system and prevent it from operating said alarm;

first time delay means responsive to arming actuation of said second switch means to provide a first time delay interval during which actuation of at least a selected one of said first switch means is ineffective to cause actuation of said alarm to thereby enable a non-intruder to exit the premises after arming said system;

and second time delay means actuatable at least by said selected one of said first switch means to provide a second time delay interval after said system is armed during which said selected one of said first switch means is ineffective to cause actuation of said alarm until lapse of said second time delay interval to thereby enable a non-intruder to enter the premises and disarm said system.