IPC 7 English version H04M !A-H04M 1/82

IPC ⁷ English version

H04M-H04M00182

H04M 3/00 - H04M 19/08

SECTION H – ELECTRICITY

H 04

ELECTRIC COMMUNICATION TECHNIQUE

H 04 M

TELEPHONIC COMMUNICATION (counting mechanisms G06M; circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08; reels or other take-up devices for cords H02G 11/00; multiplex transmission between switching centres H04J; selecting arrangements H04Q; loudspeakers, microphones, gramophone pick-ups or like electromechanical transducers H04R)

Notes

(1)

This subclass covers:

–

telephonic communication systems combined with other electrical systems;

–

testing arrangements peculiar to telephonic communication systems.

(2)

In this subclass, the following terms or expressions are used with the meanings indicated:

–

"subscriber" is a general term for terminal equipment, e.g. telephone for public use;

–

"substation" means a subscriber or monitoring equipment which may connect a single subscriber to a line without choice as to subscriber;

–

"satellite" is a type of exchange the operation of which depends upon control signals received from a supervisory exchange;

–

"switching centres" includes exchanges and satellites.

Subclass Index

TELEPHONIC SYSTEMS

Combined; party-line systems; prepayment systems

H04M 11/00; H04M 13/00; H04M 17/00

EQUIPMENTS AND ARRANGEMENTS

Equipments

H04M 1/00

Exchanges: automatic; manual

H04M 3/00; H04M 5/00

Interconnection arrangements: centralised; non-centralised

H04M 7/00; H04M 9/00

Monitoring and control; supply arrangements

H04M 15/00; H04M 19/00

Substation equipment, e.g. for use by subscribers (subscriber services or facilities provided at exchanges H04M 3/00; prepayment telephone coin boxes H04M 17/00; current supply arrangements H04M 19/08; keyboard switches in general H01H 13/70, H03K 17/94) [1,7]

Constructional features of telephone sets

Constructional features of telephone transmitters or receivers, e.g. telephone hand-sets (transducers in general H04R 1/00) [2]

Supports for telephone transmitters or receivers (for transducers in general H04R 1/00)

adapted for use on head, throat, or breast

Hooks; Cradles

associated with switches operated by weight of receiver or hand-set

associated with switches operated by magnetic effect due to proximity of receiver or hand-set

Supports for sets, e.g. incorporating armrests

Adjustable supports, e.g. extensible

pantographic

with resilient means to eliminate extraneous vibrations

Protection or guiding telephone cords (devices specially adapted or mounted for storing and repeatedly paying-out and restoring lengths of material B65H 75/34; in general H02G 11/00) [5]

Hygienic or sanitary devices on telephone equipment (for mouthpieces or earpieces H04R 1/12) [2]

Telephone sets modified for use in ships, mines, or other places exposed to adverse environment (H04M 1/19 takes precedence; telephone cabinets E04H 1/14)

Arrangements of transmitters, receivers, or complete sets to prevent eavesdropping, to attenuate local noise or to prevent undesired transmission; Special mouthpieces or receivers therefor (circuit arrangements for preventing eavesdropping H04M 1/68; telephone cabinets E04H 1/14)

Arrangements for preventing acoustic feedback (H04M 1/62 takes precedence)

Combinations with auxiliary equipment, e.g. with clock, with memoranda pad

215

by non-intrusive coupling means, e.g. acoustic couplers [7]

Illuminating; Arrangements for improving visibility of characters on dials

Construction or mounting of dials or of equivalent devices; Means for facilitating the use thereof (by improving visibility H04M 1/22)

Arrangements for testing (measuring electric values G01R; testing transducers H04R 29/00)

247

Telephone sets including user guidance or feature selection means facilitating their use [7]

253

Telephone sets using digital voice transmission (simultaneous speech and data transmission H04M 11/06) [7]

Devices for calling a subscriber (H04M 1/66 takes precedence; coding in connection with keyboards or like devices, in general H03M 11/00) [1,7]

Devices whereby a plurality of signals may be stored simultaneously [2]

272

with provision for storing only one subscriber number at a time, e.g. by keyboard or dial [2]

274

with provision for storing more than one subscriber number at a time, e.g. using toothed disc [2]

2745

using static electronic memories, i.e. memories whose operation does not require relative movement between storage means and a transducer, e.g. chip [7]

275

implemented by means of portable electronic directories [7]

2755

whose contents are provided by optical scanning [7]

276

using magnetic recording, e.g. on tape [2]

278

using punched cards or tapes [2]

Devices which can set up and transmit only one digit at a time

by interrupting current to generate trains of pulses; by periodically opening and closing contacts to generate trains of pulses [2]

315

Clutches, spring assemblies, speed regulators, e.g. centrifugal brakes (H04M 1/32 to H04M 1/40 take precedence) [3]

Locking setting devices during transmission to prevent interference by user

Lost-motion or other arrangements for ensuring a pause between successive digit transmissions

(transferred to H04M 1/677)

Pulses transmitted by a movement variably limited by the setting of a stop

wherein the setting-operation short-circuits or open-circuits the transmitting mechanism during a variable part of a cycle

by generating or selecting currents of predetermined frequencies or combinations of frequencies [2]

515

by generating or selecting other signals than trains of pulses of similar shape or other signals than currents of one or more different frequencies, e.g. generation of dc signals of alternating polarity, coded pulses, impedance dialling [2]

Arrangements wherein a dial or equivalent is mechanically coupled to a line selector

Generation of additional signals, e.g. additional pulses [2]

Arrangements wherein a dial or equivalent generates identifying signals, e.g. in party-line systems [2]

Arrangements for indicating or recording the called number at the calling subscriber's set

Arrangements for indicating or recording the number of the calling subscriber at the called subscriber's set (at the operator set in a manual exchange H04M 5/20) [2]

Anti-side-tone circuits (hybrid circuits for carrier-frequency operation H04B 1/00)

including speech amplifiers

Constructional arrangements

Automatic arrangements for answering calls; Automatic arrangements for recording messages for absent subscribers; Arrangements for recording conversations (centralised dictation systems H04M 11/10) [1,7]

Recording arrangements [2,7]

652

Means for playing back the recorded messages by remote control over a telephone line (H04M 1/658 takes precedence) [7]

654

Telephone line monitoring circuits therefor, e.g. ring detectors [7]

656

for recording conversations [7]

658

Means for redirecting recorded messages to other extensions or equipment [7]

with means for preventing unauthorised or fraudulent calling (verifying user identity or authority in secret or secure digital communications H04L 9/32) [1,7]

663

Preventing unauthorised calls to a telephone set [7]

665

by checking the validity of a code [7]

667

Preventing unauthorised calls from a telephone set (H04M 1/677 takes precedence) [7]

by electronic means [7]

673

the user being required to key in a code [7]

675

the user being required to insert a coded card, e.g. a smart card carrying an integrated circuit chip [7]

677

Preventing the dialling or sending of predetermined telephone numbers or selected types of telephone numbers, e.g. long distance [7]

Circuit arrangements for preventing eavesdropping

Lock-out or secrecy arrangements in party-line systems

Substation extension arrangements; Cordless telephones, i.e. devices for establishing wireless links to base stations without route selecting [1,7]

723

using two or more extensions per line (H04M 1/725 takes precedence) [7]

725

Cordless telephones [7]

727

Identification code transfer arrangements [7]

Battery saving arrangements [7]

733

with a plurality of base stations connected to a plurality of lines [7]

737

characterised by transmission of electromagnetic waves other than radio waves, e.g. infra-red [7]

738

Interface circuits for coupling substations to external telephone lines (H04M 1/78 takes precedence) [7]

with means for reducing interference; with means for reducing effects due to line faults

Compensating for differences in line impedance (in general H04B)

Circuit arrangements in which low-frequency speech signals proceed in one direction on the line, while speech signals proceeding in the other direction on the line are modulated on a high-frequency carrier signal (repeater circuits H04B 3/38) [2]

Telephone line holding circuits [7]

Line monitoring circuits for call progress or status discrimination [7]

H04M 3/00 - H04M 19/08