Patents
Sitemap › H04 - Electric communication technique › H04M - Telephonic communication › H04M 1 - Substation equipment, e.g. for use by subscribers
Patents for H04M 1 - Substation equipment, e.g. for use by subscribers (168,223)
04/1981
04/21/1981US4263481 Automatic telephone answering and recording apparatus
04/21/1981CA1099833A1 Telephone amplifier
04/16/1981WO1981001081A1 Coupler for telephone cords
04/15/1981EP0027044A1 Coupler for telephone cords
04/08/1981EP0026541A1 Voltage stabiliser suitable for a telephone set
04/08/1981EP0026540A1 Voltage stabiliser suitable for use in a telephone set
04/08/1981EP0026187A1 Communication system tracking arrangement.
04/07/1981US4260855 Telephone timer device
04/07/1981CA1099042A1 Signaling tone transparent echo suppressor
04/02/1981WO1981000943A1 Duplex amplifyer particularly for interphone
04/01/1981EP0026146A1 Key selecting switch and its utilisation in a telephone apparatus
04/01/1981EP0026020A1 Telephone set
04/01/1981EP0025955A1 Piezo-electric ringing transducer
03/1981
03/25/1981EP0025582A1 Arrangement for on/off switching and volume control of an amplifier in telecommunication devices by means of a single non-locking push- button
03/24/1981US4258232 Line hold circuits
03/18/1981EP0025254A1 A telephone set
03/18/1981EP0025216A1 Signalling arrangement in a voice transmission system with optically powered modules
03/17/1981US4256929 Telephone set with storing box
03/17/1981US4256928 Telephone call diverting and answering system
03/11/1981EP0024942A1 Circuits and processes for initializing the loop current of a telephone set
03/10/1981US4255634 Cam actuated switching device
03/10/1981US4255622 Emergency dialing aid and marking assembly
03/05/1981WO1981000657A1 Electronic tone ringer
03/05/1981WO1981000656A1 Acoustic coupler cavity lineariser
03/03/1981US4254442 Circuit for the protection of telephone lines
03/03/1981US4254308 Vandal resistant public telephone
03/03/1981CA1096943A1 Control circuitry for a radio telephone
02/1981
02/24/1981US4252996 Convertible acoustic telephone coupler
02/24/1981CA1096523A1 Circuit arrangement for preventing feedback
02/24/1981CA1096522A1 Subscriber line-trunk circuit
02/17/1981US4251697 Keypad for telephones
02/17/1981US4251696 Compact telescoping telephone set
02/17/1981US4251694 Tone-ringing circuits and methods for telephone sets
02/17/1981US4251693 Fixed impulse generator for hook switch flash
02/17/1981US4251692 Telephone call restricting apparatus
02/17/1981CA1096077A1 Electronic hold and hold-release circuit for a telephone set in a multiple extension single line telephone system
02/10/1981US4250356 Telephone cradle
02/10/1981CA1095430A1 Programmed conversation recording system
02/04/1981EP0023403A1 A digital loop sharing communication system and a telephone instrument for use therein
01/1981
01/20/1981US4246451 Security mounting system for coin telephone
01/20/1981US4246445 System for controlling the transmission of specific dial numbers
01/20/1981US4246444 Telephone handset acoustic coupling cup
01/13/1981CA1093720A2 Telephone range extender with gain
01/07/1981EP0021413A1 Hook switch for telephone apparatuses
01/07/1981EP0021296A1 Frequency generator for generating signalling frequencies in a multifrequency telephone apparatus
01/06/1981US4243847 Automatic restoral mechanism for a pushbutton key telephone instrument
01/06/1981US4243846 Pushbutton switch assembly for telecommunications and other input apparatus
01/06/1981US4243845 Repertory telephone dialing apparatus
01/06/1981US4243837 Telephone transmission installation between interlocutors in a noisy environment
01/06/1981CA1093232A1 Snap-in bracket for mounting a telephone dial within a telephone housing
01/06/1981CA1093194A1 Communication system conferencing arrangement
01/06/1981CA1092930A1 Telephone attachment
12/1980
12/30/1980US4242540 Automatic telephone answering device including a display for displaying indications of the various operating modes of the device
12/30/1980US4242539 Telephone information displaying device
12/30/1980US4241974 Multi-outlet adapter for modular telephone cords
12/30/1980CA1092734A2 Recursive-like adaptive echo canceller
12/23/1980US4241242 Telephone handset holder
12/23/1980US4241238 Telephone number memory and indicator system
12/23/1980US4241236 Noise range indicating system
12/16/1980CA1091833A2 Recursive-like adaptive echo canceller
12/10/1980EP0019838A1 Microphone/receiver assembly detachedly securable to a protective helmet
12/09/1980US4238647 Telephone handset having shoulder rest and adjustable earpiece
12/09/1980US4238645 Variable loop telephone transmission circuit
12/09/1980CA1091374A1 Control circuit for transfer of auxiliary telephone equipment
12/02/1980US4237350 Telephone handset
12/02/1980US4237342 Telephone hook-up box
11/1980
11/28/1980EP0016056A4 Telecommunications apparatus, e.g. a telephone, with long distance dialing lockout.
11/26/1980EP0019553A1 Autonomous device for the automatic calling via a switched network for a data processing system
11/25/1980US4236048 Electronic device for subtracting signals and associated system employing such device
11/25/1980US4236044 Remote playout control mechanism for a telephone answering device
11/25/1980US4235501 Connector
11/18/1980US4234764 Long distance telephone call security system
11/18/1980US4233766 Telephone mounting stand
11/18/1980CA1090021A2 Telephone set
11/18/1980CA1089935A1 Transceivers for single channel carrier telephone systems
11/13/1980WO1980002488A1 A balanced amplifier output stage
11/13/1980WO1980002475A1 Multi-oulet adapter for modular telephone cords
11/12/1980EP0018875A1 Automatic telephone-call generators
11/12/1980EP0018654A1 Multi-outlet adapter for modular telephone cords
11/12/1980EP0018525A1 Circuitry for a digital telephone subscriber station
11/11/1980US4233475 Telephone station with automatic switch-over between pulse code dialling and multifrequency code dialling
11/11/1980US4233474 Telephone transmitter amplifier
11/04/1980US4232203 Integral telephone set and handset
11/04/1980US4232200 Dialing system
11/04/1980US4232195 Telephone responder apparatus
11/04/1980CA1089134A1 Telephone station set interface circuit
11/04/1980CA1089129A1 Key telephone intercom line system
11/04/1980CA1089005A1 Circuit for the protection of telephone lines
10/1980
10/29/1980EP0017984A1 Mechanical telephone conversation time limiting device
10/28/1980US4230914 System for and method of indicating intruder presence on telephone lines, and method of installation of telephone intruder alarm system
10/28/1980US4230909 Telephone answering machine
10/28/1980US4230904 Signal control circuit
10/28/1980CA1088689A1 Contact slide included in the push button set of a telephone instrument
10/28/1980CA1088687A1 Automatic signal level adjusting circuits for use in telephone sets
10/28/1980CA1088683A1 Calling circuit
10/15/1980EP0017252A1 Radio installation
10/15/1980EP0016950A1 Circuit arrangement for switch-over between voice frequency signalling and speech, and vice-versa, in telecommunication apparatus
10/15/1980EP0016920A1 Circuit arrangement for telephone equipments provided with an amplifying circuit
10/14/1980US4228325 Telephone set
10/14/1980US4228323 Variable loop length compensated barrier circuit
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