DIFF Subgroup
H04M 1/27 Devices whereby a plurality of signals may be stored simultaneously
Introduced: July 1974
Full Title
Full titles differ between systems:
IPC:
Substation equipment, e.g. for use by subscribers > Devices for calling a subscriber > Devices whereby a plurality of signals may be stored simultaneously
CPC:
Substation equipment, e.g. for use by subscribers (subscriber services or facilities provided at exchanges H04M3/00; prepayment telephone coin boxes H04M17/00; current supply arrangements H04M19/08) > Devices for calling a subscriber (H04M1/66 takes precedence) > Devices whereby a plurality of signals may be stored simultaneously
Of 3 combined children, 2 exist in both systems.
1 codes are CPC-only extensions.
IPC defines codes here since 1974.
Child Classifications
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- H04M 1/272 with provision for storing only one subscriber number at a time, e.g. by keyboard or dial since 1974 +1 CPC IPC+CPC Available in IPC and CPC
- H04M 1/274 with provision for storing more than one subscriber number at a time since 1974 IPC+CPC Available in IPC and CPC