GB1385070A - Calendar timepieces - Google Patents

Abstract

1385070 Calendar timepieces EBAUCHES SA 2 May 1972 [5 May 1971] 20283/72 Heading G3T A calendar watch, e.g. an electric wristwatch, having day wheel 4 and date ring 2 respectively associated with jumpers 8 and 6, has a stem 10 with three axial positions: (a) an inner inoperative position Fig. 1, (b) a central position Fig. 2 (not shown) in which rotation of the stem in one direction causes both the day and date indicators 4, 2 to rotate, and rotation of the stem in the other direction causes only one indicator to rotate, and (c) an outer hand-setting position Fig. 3 (not shown). The indicators 4 and 2 are coupled together by a thin ring 25, Fig. 7, which is fixed to the wheel 4 but with angular play, and which has an elastic tongue 25b. When ring 2 is rotated clockwise, ratchet teeth 2b engage the tongue 25b and wheel 4 is rotated. When ring 2 is rotated anti-clockwise the tongue 25b slides over teeth 2b and wheel 4 remains stationary. In the embodiments of Figs. 9 and 10 (not shown) the ring 2 drives, directly or indirectly, a wheel upon which are mounted spring-biased pawls (34) which for one direction of rotation of ring 2 drive teeth 4a of wheel 4. In the embodiment of Fig. 11 (not shown) the coupling mechanism comprises a three-toothed wheel (39) which can drive the day wheel in only one direction since the axis of the wheel (39) is positioned asymmetrically with respect to the rest position of the day wheel teeth as determined by a jumper (43). In a final embodiment Fig. 13 (not shown) the coupling mechanism comprises a jumper (51) which is asymmetrically shaped and which acts on the date ring 2.