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
CA801832A
Inventor
P. Driver Joel
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.)
American Telephone Extension Corp
Original Assignee
American Telephone Extension Corp
Publication date
Application grantedgrantedCritical
Publication of CA801832ApublicationCriticalpatent/CA801832A/en