| 968 / | HD | HOROLOGY |
| 524 | DD | DRIVING MECHANISMS FOR CLOCKS BY MASTER CLOCKS [G04C 13/00] {2} |
| 525 | DD | .~ Circuit arrangements; electric clock installations [G04C 13/02] {5} |
| 534 | DD | .~.~ Master clocks [G04C 13/04] {4} |
| 541 | DD | .~.~.~ Arrangements for generating normal driving pulses (generating timing pulses in general subclass 817) [G04C 13/04D] {3} |
| 542 | | .~.~.~.~ By starting an independent mechanical driving device, e.g., motor controlling the contacts, etc. [G04C 13/04D2] |