|  | 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

|  | G04D |
APPARATUS OR TOOLS SPECIALLY DESIGNED FOR MAKING OR MAINTAINING CLOCKS OR WATCHES (machine tools in general Fulltext... Hierarchy... Expanded...B23, Fulltext... Hierarchy... Expanded...B24; hand tools in general Fulltext... Hierarchy... Expanded...B25)

|  | G04D |
Subclass index
HAND AND MACHINE TOOLS | 1/00, 3/00
LUBRICATING DEVICES | 5/00
MEASURING AND TESTING APPARATUS | 7/00
DEMAGNETISING DEVICES | 9/00

|  | G04D 1/00 |
Gripping, holding, or supporting devices

|  | G04D 1/02 |
· | Tweezers; Vice clamps or other special hand tools for watchmakers

|  | G04D 1/04 |
· | Tools for setting springs

|  | G04D 1/06 |
· | Supporting devices for clockworks or parts of time-pieces

|  | G04D 1/08 |
· | Tools for setting or removing hands

|  | G04D 1/10 |
· | Devices for opening or closing watch bottoms or covers

|  | G04D 3/00 |
Watchmakers' or watch-repairers' machines or tools for working materials

|  | G04D 3/02 |
· | Lathes, with one or more supports; Burnishing machines, with one or more supports

|  | G04D 3/04 |
· | Devices for placing bearing jewels, bearing sleeves, or the like in position

|  | G04D 3/06 |
· | Devices for shaping or setting watch glasses

|  | G04D 3/08 |
· | Machines or apparatus for cleaning

|  | G04D 5/00 |
Oiling devices; Special lubricant containers for watchmakers

|  | G04D 7/00 |
Measuring, counting, calibrating, testing, or regulating apparatus

|  | G04D 7/02 |
· | for mainsprings

|  | G04D 7/04 |
· | for gearwork

|  | G04D 7/06 |
· | for escapements

|  | G04D 7/08 |
· | for balance wheels

|  | G04D 7/10 |
· | for hairsprings

|  | G04D 7/12 |
· | Timing devices for clocks or watches for comparing the rate of the oscillating member with a standard

|  | G04D 9/00 |
Demagnetising devices (demagnetising in general Fulltext... Hierarchy... Expanded...H01F 13/00)