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:
Jul. 19, 1988
Filed:
Dec. 22, 1986
Applicant:
Inventor:
Regis B Mellon, Mulberry, FL (US);
Assignee:
Protel, Inc., Lakeland, FL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04M / ; H04M / ;
U.S. Cl.
CPC ...
379145 ; 379123 ;
Abstract
A toll telephone connected to a coin trunk including tip and ring conductors in which loop current flows from the central office and through the telephone responsive to an off-hook condition at the telephone includes electronic circuitry for maintaining the loop current flow through the telephone for a predetermined period of time after the hook switch is opened, in order to accomplish certain telephone functions. Those functions include operation of an escrow relay, prevention of hook switch fraud, prevention of central office call termination until the call is legitimately completed and completion of certain call accounting functions.