×

Security alarm system and switch

  • US 4,977,392 A
  • Filed: 05/15/1989
  • Issued: 12/11/1990
  • Est. Priority Date: 05/15/1989
  • Status: Expired due to Fees
First Claim
Patent Images

1. An alarm system for detection of the movement of an object comprising:

  • a housing;

    a lever arm having a sensing extremity and a contact extremity, said lever arm being pivotally mounted intermediate said extremities;

    extensible means under tension affixed to said housing and said lever arm for urging said lever arm about said pivot and causing said contact extremity to close electrical contacts; and

    electronic means for generating a pulsating audible tone upon closing of said electrical contacts, said electronic means including;

    an annunciator device, a first oscillator circuit coupled to said annunciator to generate a tone therefrom, and a second oscillator for periodically disabling said first oscillator to provide a pulsing effect, and said electronic means further comprising;

    a first timing circuit for disabling said first oscillator circuit after a first set time delay and a second timing circuit for enabling said first oscillator after a second set time delay.

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