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:
Nov. 08, 1977
Filed:
Jul. 28, 1976
Ronald Joseph Angner, Freehold, NJ (US);
Marion Lee Blount, Palo Alto, CA (US);
James Volney Lacy, Red Bank, NJ (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
An electronic key telephone line circuit is disclosed for controlling the hold and disconnect conditions with respect to associated telephone stations in response to transient signals generated upon on-hook to off-hook and off-hook to on-hook transitions of those stations. Due to the nature of the switchhook contacts, the tip and ring leads open before the A-lead opens. Since the disconnect condition is determined from a transient signal caused by the tip and ring lead opening together with an A-lead open, and since by its very nature the transient response of the tip and ring lead transition can be finished before the A-lead opens, timing is used to delay the transient signal to insure that the line circuit goes into the proper mode.