| 摘要 |
A clock equipped with an electrical or mechanical alarm device has an hour-setting disk and a minute-setting disk which are independently indexable in 24 and 60 different angular positions, respectively, and whose hour and minute markings are visible through a window or windows in the clock housing. Each setting disk is under axial spring pressure and bears a lug which rides on a face of an adjoining follower disk driven by the clockwork at a rate of one or two revolutions per day and one revolution per hour, respectively. Once per revolution, a notch on the face of each follower disk aligns itself with the lug of the associated setting disk to permit axial displacement of the latter; when both setting disks are simultaneously displaced in this manner, the alarm is triggered. |
