|  | G |
SECTION G — PHYSICS

INSTRUMENTS

|  | G04 |
HOROLOGY

|  | G04B |
MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME-PIECES USING THE POSITION OF THE SUN, MOON, OR STARS (spring- or weight-driven mechanisms in general Fulltext... Hierarchy... Expanded...F03G; electromechanical clocks or watches Fulltext... Hierarchy... Expanded...G04C; electromechanical clocks with attached or built-in means operating any device at preselected times or after predetermined time intervals Fulltext... Hierarchy... Expanded...G04C 23/00; clocks or watches with stop devices Fulltext... Hierarchy... Expanded...G04F 7/08)

|  | G04B |
Note(s) This sub-class includes mechanically-driven calendar clocks or clockwork calendars, and the mechanical part of such clocks or calendars.

|  | 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 sub-class includes electric features of mechanically-driven clocks or watches, such as electric winding of such clocks or the provision of electric contacts thereon.

|  | 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)

|  | G04F |
TIME-INTERVAL MEASURING (measuring pulse characteristics Fulltext... Hierarchy... Expanded...G01R, e.g. Fulltext... Hierarchy... Expanded...G01R 29/02; in radar or like systems Fulltext... Hierarchy... Expanded...G01S; masers Fulltext... Hierarchy... Expanded...H01S 1/00; generation of oscillations Fulltext... Hierarchy... Expanded...H03B; generation or counting of pulses, frequency dividing, analogue/digital conversion Fulltext... Hierarchy... Expanded...H03K) [2]

|  | G04F |
Note(s) This sub-class includes: apparatus for measuring-off predetermined time intervals; apparatus for producing such intervals as timing standards, e.g. metronomes; apparatus for measuring unknown intervals, e.g. precision systems for short-time-interval measurement. [2]

|  | G04G |
ELECTRONIC TIME-PIECES [3]

|  | G04G |
Note(s) This sub-class covers: [3] electronic time-pieces with no moving parts (electronic time-pieces with moving parts are covered by sub-class Fulltext... Hierarchy... Expanded...G04C); [3] electronic circuitry for producing timing pulses irrespective of the nature of the time-indicating means utilised. [3]