GB1110717A - Alarm-bell mechanism for an alarm clock - Google Patents

Abstract

1,110,717. Ringer for alarm clock. FABRIQUE D'HORLOGERIE CHS. TISSOT ET FILS S.A. 7 Oct., 1965 [9 Oct., 1964; 8 Sept., 1965], No. 42652/65. Heading G5J. [Also in Division G3] When the alarm clock of which 1 is the bell rings, a spring attached to face cam 11 drives the hammer 3 through gear train 7, 6, 5 and escapement 15, the cam 11 and wheel 7 making less than a single turn during the ringing. Escapement 15 turns on pin 16 and has a stud 20 which strikes hammer 3 when output projection 18 is expelled from the teeth of wheel 5. Hammer 3 rises, swinging on its mount 4, to the dotted position and input projection 19 locks wheel 5 until the hammer returns under its own weight, strikes. stud 20, so unlocking wheel 5, and rings the bell. As cam 11 rotates, stud 30 on resilient rocker 24 follows U-shaped grooves 27, 28 and 28a, moving towards and away from the centre of the cam and the rocker rotates clockwise and anticlockwise on its mount 25. Spring 21 restricts the rise of the hammer when in position 21<SP>1</SP>, and causes its early return, but has no effect when in the position shown by full lines. Pins 26. move spring 21 between the two positions shown for it and so produce a variation in the rate at which hammer 3 strikes bell 1. When rod 2 is depressed the rocker is rotated clockwise, the abutment 33 moves the hammer to an inactive position by bearing on stud 23 and pins 26 move the spring 21 and its other arm 34 anticlockwise, so that the arm 34 presses on stud 35 and disengages the escapement. At the same time stud 30 is forced from groove 27, 28 or 28a to groove 29 and the mechanism idles until with continuing rotation of cam 11 stud 30 reaches the end of groove 29 and is forced by the weight of hammer 3, acting through rocker 24, to move along radial groove 31 towards the centre of the cam. Rewinding restores it to the position shown in Fig. 1. If rod 2 is displaced by a screw in its mount, prior to its depression, into the position shown by broken lines in Fig. 1 the clockwise movement of rocker 24 is restricted, so that stud 30 is unable to move into groove 28 and instead mounts its shoulder and drops into groove 27 again. In this way the ringing of the bell can be kept, if desired, to its initial slow speed. An alternative escapement (Figs. 4 and 5, not shown) for use in a ringing mechanism of this kind, in which the input and output projections are carried by separate components, articulated so as to be capable of moving through a limited angle relative to one another is described.