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:
Sep. 06, 1977
Filed:
Sep. 03, 1976
Barry William Rogers, Geneva, IL (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
This invention pertains to systems servicing coin operated telephones and, more specifically, to apparatus in such systems for detecting when called parties fraudulently generate coin deposit tones to simulate the coin deposit tones which should be received from a calling coin station. During intermediate coin deposit intervals, the network connection between the calling and called stations is split. A first coin tone detector is connected to the calling station portion while a second coin tone detector is connected to the called station portion. Logic is responsive to the detection of coin tones by these detectors for indicating whether a detected coin tone is valid or fraudulent.