| 968 / | HD | HOROLOGY |
| 801 | DD | APPARATUS WHICH CAN BE SET AND STARTED TO MEASURE OFF PREDETERMINED OR ADJUSTABLY FIXED TIME INTERVALS WITHOUT DRIVING MECHANISMS, E.G., EGG TIMER, ETC. (electric time and time-program switches H01H 43/00) [G04F 1/00] {3} |
| 804 | DD | .~ By movement or acceleration due to gravity [G04F 1/04] {2} |
| 805 | DD | .~.~ By flowing away of a prefixed quantity of fine granular or liquid materials, e.g., sand-glass, water-clock, etc. [G04F 1/06] {2} |
| 806 | | .~.~.~ Using acoustic signalling [G04F 1/06B] |