Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS3341662 A
Publication typeGrant
Publication dateSep 12, 1967
Filing dateNov 26, 1963
Priority dateNov 26, 1963
Publication numberUS 3341662 A, US 3341662A, US-A-3341662, US3341662 A, US3341662A
InventorsCerny Louis J, Curtis Robert B, Nightingale John G, Orfeo Cesareo, Parkinson Jr Frederick H
Original AssigneeBell Telephone Labor Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Equipment for operator served calls at an intermediate switching center
US 3341662 A
Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2357756 *Jan 3, 1942Sep 5, 1944Musher Foundation IncProcess of preparing a vitamin b complex concentrate
US3019294 *Jul 3, 1959Jan 30, 1962Automatic Elect LabPaystation customer dialling in a toll ticketing telephone system
US3133153 *Oct 7, 1960May 12, 1964Automatic Elect LabSpecial service toll telephone system
US3218392 *Oct 10, 1961Nov 16, 1965North Electric CoSignalling system for use with toll ticketing equipment
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3499117 *May 19, 1967Mar 3, 1970Communication Equipment & EngRemote operator coin control using multi-frequency tones
US4007339 *Nov 28, 1975Feb 8, 1977Bell Telephone Laboratories, IncorporatedArrangement serving operator assistance calls requiring routing back to originating offices
US4145578 *Apr 28, 1978Mar 20, 1979Bell Telephone Laboratories, IncorporatedPosition access preference method
U.S. Classification379/121.1, 379/201.1, 379/224, 379/123
International ClassificationH04Q3/00
Cooperative ClassificationH04Q3/0016
European ClassificationH04Q3/00D