×

Code combination property alarm system

  • US 4,114,147 A
  • Filed: 03/24/1977
  • Issued: 09/12/1978
  • Est. Priority Date: 03/24/1977
  • Status: Expired due to Term
First Claim
Patent Images

1. A property protection alarm system for protecting property against unauthorized intrusion and the like comprising:

  • sensing means for sensing an alarm condition such as any intrusion of the property, said sensing means including means for detecting movement through normal entrance to the property;

    a local audible alarm;

    an external alarm;

    alarm energization means responsive to said sensing means for energizing said local audible alarm for a given alarm interval upon the occurrence of any intrusion of the property including an authorized intrusion through said normal entrance and energizing said external alarm only after a predetermined entrance delay period;

    arming means connected to said alarm energization means for enabling an authorized user of said alarm system to arm and disarm said alarm energization means, said arming means including a numeric keyboard having a plurality of keys and a code combination logic circuit connected thereto for arming and disarming said alarm energization means in response to a predetermined numeric code entered in said numeric keyboard by actuation of selected ones of said keys, said code combination logic circuit including code timing means responsive to the actuation of the first of said selected ones of said keys associated with the predetermined numeric code for establishing a predetermined code interval in which all of the remaining ones of said selected ones of said keys associated with the predetermined numeric code must be actuated in order to arm or disarm said alarm energization means;

    said alarm energization means including exit delay means actuated by said arming means for delaying only the arming of said alarm energization means by said arming means for a predetermined exit delay period to permit the authorized user of said alarm system to leave the property through said normal entrance without energizing either said local audible alarm or said external alarm, said alarm energization means further including entrance delay means connected to said external alarm for delaying energization of said external alarm for the predetermined entrance delay period to permit the authorized user to enter the property through said normal entrance without energizing said external alarm and disarm said alarm system by actuating said arming means, said local audible alarm being immediately energized for a given alarm interval in response to any intrusion of the property including an authorized intrusion through said normal entrance.

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