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. 17, 1991
Filed:
Jan. 03, 1991
Applicant:
Inventor:
Fumihiro Ikawa, Yokohama, JP;
Assignee:
Fujitsu Limited, Kawasaki, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04Q / ; G06F / ;
U.S. Cl.
CPC ...
340825160 ; 340827 ; 34082503 ; 379-2 ; 371-81 ;
Abstract
A one-to-one line switching system for switching between a hot line and a standby line in a one-to-one correspondence. To enable removal of a switching unit while in use, from a mother board for change over or repair, a pair of switching units (1 and 2 or 3 and 4) is provided at the transmitting part and at the receiving part, respectively, the earth element in one of the pair being connected to the other of the pair and the other of the pair being pulled up by a voltage, whereby, when one of the pair in use is removed, the other of the pair can pass the input signal.