The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 03, 1980
Filed:
Jul. 27, 1977
Aaron A Galvin, Nahant, MA (US);
Sheldon P Apsell, Nahant, MA (US);
Daniel Crown, West Newton, MA (US);
American District Telegraph Company, New York, NY (US);
Abstract
A multiple sensor intrusion alarm system including a central controller which communicates with a plurality of sensors over a single, interconnecting cable. The controller periodically polls each of the sensors, and in response to this polling signal, each sensor returns a signal indicating its status. The absence of a return signal from a particular sensor indicates to the controller that the sensor is malfunctioning or has been tampered with. In a preferred embodiment, the interconnecting cable is a single, two-conductor cable. The controller may also be connected to an alarm panel or remote monitoring station to indicate the presence of an alarm condition.