公开(公告)号：US3270140A

公开(公告)日：1966-08-30

申请号：US27792663

申请日：1963-05-03

Applicant: BELL TELEPHONE LABOR INC

Inventor： BROOKS CHESTER E ,  CROFUTT JR GEORGE B ,  SAND WILLIAM C

IPC: H04Q3/58

CPC classification number: H04Q3/58

公开(公告)号：US3198887A

公开(公告)日：1965-08-03

申请号：US15346861

申请日：1961-11-20

Applicant: BELL TELEPHONE LABOR INC

Inventor： BROOKS CHESTER E ,  SAND WILLIAM C

IPC: H04Q3/00

CPC classification number: H04Q3/0004

公开(公告)号：US3627950A

公开(公告)日：1971-12-14

申请号：US3627950D

申请日：1969-10-07

Applicant: BELL TELEPHONE LABOR INC

Inventor： SAND WILLIAM C

IPC: H04M17/02

CPC classification number: H04M17/023

Abstract: A dial-tone-first coin telephone circuit is disclosed in which a battery reversal from the central office switches the circuit between two modes of coin signaling. A relay coil is connected between the ring terminal and ground, to disconnect an initial deposit circuit from the station loop except in response to a predetermined signal sent on the ring conductor.

公开(公告)号：US3412211A

公开(公告)日：1968-11-19

申请号：US49362765

申请日：1965-10-07

Applicant: BELL TELEPHONE LABOR INC

Inventor： CHARLES ABERT ,  SAND WILLIAM C

IPC: H04Q3/00

CPC classification number: H04Q3/0004

公开(公告)号：US3190967A

公开(公告)日：1965-06-22

申请号：US24863462

申请日：1962-12-31

Applicant: BELL TELEPHONE LABOR INC

Inventor： SAND WILLIAM C

IPC: H04Q3/00

CPC classification number: H04Q3/0004

公开(公告)号：US3165590A

公开(公告)日：1965-01-12

申请号：US16318661

申请日：1961-12-29

Applicant: BELL TELEPHONE LABOR INC

Inventor： BROOKS CHESTER E ,  CROFUTT JR GEORGE B ,  SAND WILLIAM C

IPC: H04M19/04

CPC classification number: H04M19/04

公开(公告)号：US3129292A

公开(公告)日：1964-04-14

申请号：US7938560

申请日：1960-12-29

Applicant: BELL TELEPHONE LABOR INC

Inventor： BROOKS CHESTER E ,  SAND WILLIAM C

IPC: H04Q3/00

CPC classification number: H04Q3/0004