Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA778950A
Inventor
T. Fought Benjamin
David Muir, Iii
B. Macurdy William
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AT&T Corp
Original Assignee
Western Electric Co Inc
Publication date
Application grantedgrantedCritical
Publication of CA778950ApublicationCriticalpatent/CA778950A/en