GB1378249A - Calendar-watch with day-of-the week and date indicating means - Google Patents

Abstract

1378249 Calendar watches FABRIQUE D'HORLOGERIE CHS TISSOT ET FILS SA 14 April 1972 [16 April 1971] 17338/72 Heading G3T A calendar watch having hands and concentric day and date rings 10 and 6, is corrected by rotating a calendar setting wheel 8 having fingers 36, 37 which respectively engage teeth 15, 7 on the rings 10, 6. Rotation of the wheel 8 is effected by rotating the winding stem in the hand-setting position. The fingers 36, 37 are not located diametrically opposite on the wheel 8, so that by to and fro rotation of the winding stem, with the hands indicating approximately midnight, the date ring alone can be indexed, and with the hands near the 1 a.m. position, the day ring can be similarly indexed alone. Jumpers 17, 20 respectively hold rings 10, 6 so that each set of teeth 15, 7 is portioned asymmetrically with respect to a straight line between the centre of wheel 8 and the common centre of the rings 10, 6. Thus forward winding of the stem indexes the rings, whereas the jumpers prevent backward winding of the stem from indexing the rings in the opposite direction. During normal operation of the watch, wheel 8 is indexed by teeth 32 on the hour wheel engaging sets of teeth 38, 39. Between indexing, enlarged gaps 40, 41 between teeth sets 38, 39 are held by the periphery 31 of the hour wheel. In a modification the wheel 8 is used for correction purposes only, a further mechanism driving the rings 10, 6. Axial play of the hour wheel is prevented by three resilient fingers 29 pressing against a bridge 9.