GB1052195A - - Google Patents

Abstract

1,052,195. Clocks and watches. H.T, GRISEBACH. Aug.2, 1963 [Aug.4, 1962; Oct. 9, 1962 and Nov. 29, 1962], No.30724/63. Heading G3T. [Also in Division F2] A time delay mechanism, for use e.g. in an industrial alarm clock, comprises a flat helical spring 12 attached between a pin 5 and a flange 14 on a drum 13 rotatably mounted on the end of the pin 5 which is riveted, at 3, eccentrically to a base plate 2 and has a frusto-conical stator portion 4, and a ratchet wheel 6 which has a rotor collar 7 which co-operates with the stator 4 and peripheral teeth adapted to engage with a tongue 15, Fig.2 (not shown), bent inwardly from the drum 13, a layer of silicone putty 8 being located between the stator 4 and the collar 7 and the supply of putty being maintained from a small reservoir 9 trapped between the collar 7 and a flange 10 on the base plate 2. When the spring 12 is tensioned the tongue 15 rotates the wheel 3 the speed of which is determined by the resistance of the layer 8. Due to the eccentricity of the stator 4, at a certain point, the tongue 15 disengages from the teeth of the wheel 6 so that the housing 13 can rotate freely carrying a striker with it. In a modification Fig. 3 (not shown), a simple form of stop watch comprises a housing 20 having a front face 21 with time marks and a fixed spindle 22 upon which is mounted, with the interposition of silicone putty 25, a cap 23 which carries an indicator finger 24. A drum 26, with an enclosed spring 27 connected to the cap 23 through a slipping clutch, has edge teeth 28 engaged by a toothed wheel 32 on the shaft 31 of an operating knob 30 for winding up the spring 27. With the spring 27 under tension the cap 23 is driven at a speed determined by the silicone putty 25. The finger 24 can be set at zero by displacing the shaft 31 longitudinally against a spring 35 so that an abutment 34 on the shaft can set an eccentric 33 on the cap 23 in a predetermined position held by a spring 36.