|  | G |
SECTION G — PHYSICS

|  | G |
Note(s) In this section, the following term is used with the meaning indicated: "variable" (as a noun) means a feature or property (e.g., a dimension, a physical condition such as temperature, a quality such as density or colour) which, in respect of a particular entity (e.g., an object, a quantity of a substance, a beam of light) and at a particular instant, is capable of being measured; the variable may change, so that its numerical expression may assume different values at different times, in different conditions or in individual cases, but may be constant in respect of a particular entity in certain conditions or for practical purposes (e.g., the length of a bar may be regarded as constant for many purposes). Attention is drawn to the definitions of terms or expressions used, appearing in the notes of several of the classes in this section, in particular those of "measuring" in class Fulltext... Hierarchy... Expanded...G01 and "control" and "regulation" in class Fulltext... Hierarchy... Expanded...G05. Classification in this section may present more difficulty than in other sections, because the distinction between different fields of use rests to a considerable extent on differences in the intention of the user rather than on any constructional differences or differences in the manner of use, and because the subjects dealt with are often in effect systems or combinations, which have features or parts in common, rather than "things", which are readily distinguishable as a whole. For example, information (e.g., a set of figures) may be displayed for the purpose of education or advertising (Fulltext... Hierarchy... Expanded...G09), for enabling the result of a measurement to be known (Fulltext... Hierarchy... Expanded...G01), for signalling the information to a distant point or for giving information which has been signalled from a distant point (Fulltext... Hierarchy... Expanded...G08). The words used to describe the purpose depend on features that may be irrelevant to the form of the apparatus concerned, for example, such features as the desired effect on the person who sees the display, or whether the display is controlled from a remote point. Again, a device which responds to some change in a condition, e.g., in the pressure of a fluid, may be used, without modification of the device itself, to give information about the pressure (Fulltext... Hierarchy... Expanded...G01L) or about some other condition linked to the pressure (another subclass of class Fulltext... Hierarchy... Expanded...G01, e.g., Fulltext... Hierarchy... Expanded...G01K for temperature), to make a record of the pressure or of its occurrence (Fulltext... Hierarchy... Expanded...G07C), to give an alarm (Fulltext... Hierarchy... Expanded...G08B), or to control another apparatus (Fulltext... Hierarchy... Expanded...G05). The classification scheme is intended to enable things of a similar nature (as indicated above) to be classified together. It is therefore particularly necessary for the real nature of any technical subject to be decided before it can be properly classified.

INSTRUMENTS

|  | G04 |
HOROLOGY

|  | G04C |
ELECTROMECHANICAL CLOCKS OR WATCHES (mechanical parts of clocks or watches in general Fulltext... Hierarchy... Expanded...G04B; electronic time-pieces with no moving parts, electronic circuitry for producing timing pulses Fulltext... Hierarchy... Expanded...G04G)

|  | G04C |
Note(s) This subclass covers electric features of mechanically-driven clocks or watches, such as electric winding of such clocks or the provision of electric contacts thereon.

|  | G04C |
Subclass index
ELECTRIC WINDING OF MECHANICAL CLOCKS | 1/00
ELECTROMECHANICAL CLOCK MOVEMENTS; ELECTRIC OR MAGNETIC ESCAPEMENTS | 3/00, 5/00
TIME INDICATING |
Optical; acoustical means | 17/00, 19/00; 21/00
TIME SETTING | 9/00
POWER SUPPLIES | 10/00
SYNCHRONISATION; MASTER-AND-SLAVE CLOCK SYSTEM; SYNCHRONOUS-MOTOR CLOCKS | 11/00; 13/00; 15/00
CLOCKS FOR OPERATING A DEVICE AT A PRESELECTED TIME | 23/00

|  | G04C 1/00 - G04C 10/00 |
Electric winding of mechanical clocks; Independent electric clocks or watches

|  | G04C 1/00 |
Winding mechanical clocks electrically (winding mechanically Fulltext... Hierarchy... Expanded...G04B 3/00)

|  | G04C 1/02 |
· | by electromagnets

|  | G04C 1/04 |
· | by electric motors with rotating or with reciprocating movement

|  | G04C 1/06 |
· · | winding-up springs

|  | G04C 1/08 |
· · | raising weights

|  | G04C 1/10 |
· | Protection against overwinding (in mechanical clocks or watches Fulltext... Hierarchy... Expanded...G04B 1/20, Fulltext... Hierarchy... Expanded...G04B 3/06, Fulltext... Hierarchy... Expanded...G04B 3/10)

|  | G04C 1/12 |
· · | of the spring

|  | G04C 1/14 |
· · | of the weights

|  | G04C 3/00 |
Electromechanical clocks or watches independent of other time-pieces and in which the movement is maintained by electric means

|  | G04C 3/02 |
· | wherein movement is regulated by a pendulum

|  | G04C 3/027 |
· · | using electromagnetic coupling between electric power source and pendulum (Fulltext... Hierarchy... Expanded...G04C 3/033 takes precedence) [3]

|  | G04C 3/033 |
· · | using torsion pendulums; using conical pendulums (construction thereof Fulltext... Hierarchy... Expanded...G04B 17/00) [3]

|  | G04C 3/04 |
· | wherein movement is regulated by a balance

|  | G04C 3/06 |
· · | using electromagnetic coupling between electric power source and balance [3]

|  | G04C 3/08 |
· | wherein movement is regulated by a mechanical oscillator other than a pendulum or balance, e.g. by a tuning fork [3]

|  | G04C 3/10 |
· · | driven by electromagnetic means [3]

|  | G04C 3/12 |
· · | driven by piezo-electric means; driven by magneto-strictive means [3]

|  | G04C 3/14 |
· | incorporating a stepping motor (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G04C 3/02-G04C 3/12 take precedence) [3]

|  | G04C 3/16 |
· | incorporating an electro-dynamic continuously rotating motor (Fulltext... Hierarchy... Expanded...Fulltext... Hierarchy... Expanded...G04C 3/02-G04C 3/12 take precedence; clocks driven by synchronous motors Fulltext... Hierarchy... Expanded...G04C 15/00) [3]

|  | G04C 3/18 |
· | incorporating electro-thermal or electro-pneumatic driving means [3]

|  | G04C 5/00 |
Electric or magnetic means for converting oscillatory to rotary motion in time-pieces, i.e. electric or magnetic escapements (regulators Fulltext... Hierarchy... Expanded...G04C 3/00) [3]

|  | G04C 9/00 |
Electrically-actuated devices for setting the time-indicating means (of slave clocks Fulltext... Hierarchy... Expanded...G04C 13/03; mechanical setting devices Fulltext... Hierarchy... Expanded...G04B 27/00) [3]

|  | G04C 9/02 |
· | brought into action by radio transmission

|  | G04C 9/04 |
· | by blocking the driving means [3]

|  | G04C 9/06 |
· | by decoupling the driving means (combined with blocking means Fulltext... Hierarchy... Expanded...G04C 9/04) [3]

|  | G04C 9/08 |
· | by electric drive [3]

|  | G04C 10/00 |
Arrangements of electric power supplies in time-pieces [3]

|  | G04C 10/02 |
· | the power supply being a radioactive source [3]

|  | G04C 10/04 |
· | with means for indicating the condition of the power supply [3]

|  | G04C 11/00 - G04C 15/00 |
Electric clock installations; Master-and-slave clock systems; Synchronous-motor clocks

|  | G04C 11/00 |
Synchronisation of independently-driven clocks

|  | G04C 11/02 |
· | by radio

|  | G04C 11/04 |
· | over a line (transmitting time signals over telephone networks Fulltext... Hierarchy... Expanded...H04M 11/06)

|  | G04C 11/06 |
· | with direct mechanical action on the time-indicating means [3]

|  | G04C 11/08 |
· | using an electric magnet or motor [3]

|  | G04C 13/00 |
Driving mechanisms for clocks by master clocks

|  | G04C 13/02 |
· | Circuit arrangements; Electric clock installations

|  | G04C 13/03 |
· · | Pulse transmission systems with additional means for setting the time indication of slave clocks [3]

|  | G04C 13/04 |
· · | Master clocks

|  | G04C 13/06 |
· · · | Contact devices (for simultaneously winding several clocks Fulltext... Hierarchy... Expanded...G04C 1/00)

|  | G04C 13/08 |
· | Slave clocks actuated intermittently

|  | G04C 13/10 |
· · | by electromechanical step-advancing mechanisms

|  | G04C 13/11 |
· · · | with rotating armature [3]

|  | G04C 13/12 |
· · | by continuously-rotating electric motors [3]

|  | G04C 13/14 |
· · | by electrically-released mechanical driving mechanisms

|  | G04C 15/00 |
Clocks driven by synchronous motors

|  | G04C 17/00 - G04C 23/00 |
Indicating the time or producing time signals electrically

|  | G04C 17/00 |
Indicating the time optically by electric means (Fulltext... Hierarchy... Expanded...G04C 19/00 takes precedence; liquid crystal materials Fulltext... Hierarchy... Expanded...C09K 19/00; by mechanical means Fulltext... Hierarchy... Expanded...G04B 19/00, Fulltext... Hierarchy... Expanded...G04B 19/20) [3]

|  | G04C 17/02 |
· | by electric lamps

|  | G04C 19/00 |
Producing optical time signals at prefixed times by electric means

|  | G04C 19/02 |
· | by electric lamps

|  | G04C 19/04 |
· | by indicating members moved electrically, e.g. flap, band

|  | G04C 21/00 |
Producing acoustic time signals by electrical means

|  | G04C 21/02 |
· | Constructional details (Fulltext... Hierarchy... Expanded...G04C 21/04, Fulltext... Hierarchy... Expanded...G04C 21/16 take precedence)

|  | G04C 21/04 |
· | Indicating the time of the day (acoustic indication of time Fulltext... Hierarchy... Expanded...G04B 21/00)

|  | G04C 21/06 |
· · | by striking mechanism

|  | G04C 21/08 |
· · · | with snail

|  | G04C 21/10 |
· · · | with locking plate

|  | G04C 21/12 |
· · | by electro-acoustic means

|  | G04C 21/14 |
· · · | Electro-acoustic time announcement, i.e. spoken

|  | G04C 21/16 |
· | producing the signals at adjustable fixed times

|  | G04C 21/18 |
· · | by mechanically unlocking an electromechanical vibrator, e.g. actuated by the leakage flux of the electric driving means

|  | G04C 21/20 |
· · | by closing a contact to ring an electromechanical alarm

|  | G04C 21/22 |
· · · | put into action by the arbor of a mechanical alarm work

|  | G04C 21/24 |
· · · | put into action by the spring of a mechanical alarm work

|  | G04C 21/26 |
· · · | put into action by the vibrations caused by the operation of a mechanical alarm work

|  | G04C 21/28 |
· · | by closing a contact to put into action electro-acoustic means, e.g. awakening by music

|  | G04C 21/30 |
· · | with provision for a number of operations at different times, e.g. ringing the bells in a school

|  | G04C 21/32 |
· · · | giving indications at a number of places, each at a different time, e.g. system of alarms in a hotel

|  | G04C 21/34 |
· · | Devices on watches or similar portable time-pieces

|  | G04C 21/36 |
· · | Signal-repeating devices

|  | G04C 21/38 |
· · | Adjusting the duration of signals

|  | G04C 23/00 |
Clocks with attached or built-in means operating any device at preselected times or after preselected time-intervals (if restricted to producing acoustic time signals by electrical means Fulltext... Hierarchy... Expanded...G04C 21/00; mechanical alarm clocks Fulltext... Hierarchy... Expanded...G04B 23/02; apparatus which can be set and started to measure-off predetermined intervals Fulltext... Hierarchy... Expanded...G04F 3/06; time or time-programme switches which automatically terminate their operation after the programme is completed Fulltext... Hierarchy... Expanded...H01H 43/00)

|  | G04C 23/02 |
· | Constructional details

|  | G04C 23/04 |
· · | Housings, supports, shielding, or similar stationary parts

|  | G04C 23/06 |
· · | Driving or regulating means

|  | G04C 23/08 |
· · | Programming means

|  | G04C 23/10 |
· · | for actuating any element which operates, or initiates the operation of, the device concerned

|  | G04C 23/12 |
· · | Electric circuitry

|  | G04C 23/14 |
· | Mechanisms continuously running to relate the operation(s) to the time of day

|  | G04C 23/16 |
· · | acting only at one preselected time or during one adjustable time interval

|  | G04C 23/18 |
· · | for operating one device at a number of different times

|  | G04C 23/20 |
· · · | with contacts operated, or formed, by clock hands or elements of similar form

|  | G04C 23/22 |
· · · | with the actuating element carried by a disc

|  | G04C 23/24 |
· · · · | the actuating element controlling another element mechanically

|  | G04C 23/26 |
· · | for operating a number of devices at different times

|  | G04C 23/28 |
· · · | with contacts operated, or formed, by clock hands or elements of similar form

|  | G04C 23/30 |
· · · | with the actuating element carried by a disc

|  | G04C 23/32 |
· · · · | the actuating element controlling another element mechanically

|  | G04C 23/34 |
· · | with provision for automatic modification of the programme, e.g. on Sunday

|  | G04C 23/36 |
· · · | by external influences

|  | G04C 23/38 |
· | Mechanisms measuring a chosen time interval independently of the time of day at which the interval starts

|  | G04C 23/40 |
· · | using continuously-running mechanism

|  | G04C 23/42 |
· · | acting only at the end of a single time interval

|  | G04C 23/44 |
· · · | with provision for selection from a number of preset intervals

|  | G04C 23/46 |
· · · | with provision for adjustment of the interval (Fulltext... Hierarchy... Expanded...G04C 23/44 takes precedence)

|  | G04C 23/48 |
· · | acting at the ends of successive time intervals

|  | G04C 23/50 |
· · | with provision for modification of the interval(s) by external influences