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:
Dec. 01, 1981
Filed:
Apr. 25, 1978
Applicant:
Inventor:
John D McCann, Abingdon, GB;
Assignee:
Parmeko Limited, Leicester, GB;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G08B / ; G08B / ;
U.S. Cl.
CPC ...
340572 ; 340568 ; 343 / ;
Abstract
A system for monitoring the position of a receptor reradiator in a surveillance zone having a first means for transmitting a first signal through the zone, and a receptor reradiator operable in response to reception of said signal to radiate at least one reply signal which is a function of the first signal and of the position of said receptor reradiator in the zone. There is also a receiver for receiving the reply signal, means controlled by the receiver, dependent upon the reply signal to indicate the position of the receptor reradiator in the zone, and an alarm triggerable by the receiver responsive to the latter for receiving the reply signals.