GB703362A - Improvements in or relating to automatic winding devices for watches - Google Patents

Abstract

703,362. Watches. COMPAGNIE HORLOGENE ULTRA. Jan. 4, 1951 [Jan. 4, 1950; Oct. 28, 1950], No. 344/51. Class 139 An automatic watch-winding mechanism of the type in which an inertia mass is pivoted so that it can turn freely about its pivotal axis without limitation of movement to effect winding of the watch mechanism in both directions of rotation of the mass, comprises a cam fixed with respect to the inertia mass and capable of pivoting about said axis, and a device comprising two opposed pawls which can engage with a ratchet wheel, of which the rotation in a certain direction effects the winding of the watch spring, in such manner that when the two pawls are moved in one direction one of the pawls slips on the ratchet wheel and the other engages to turn this wheel in said certain direction, and when the two pawls are moved in the other direction the first pawl engages to turn the ratchet wheel in said certain direction whilst the second pawl slips on the ratchet wheel, and means controlled by the pivoting of the cam for moving the pawls so that the movement of the inertia mass in either direction about its pivot always ensures the rotation of the ratchet wheel in the said certain direction and consequently the winding of the watch spring. The oscillating inertia mass or weight 14, Figs. 1 and 3, is pivotally mounted by a screw 15 on a shaft 11 carried by a casing 1 fixed to and covering the movement 2. The shaft 11 has an eccentric neck 12 carrying a roller 13 which, as the shaft rotates in either direction, imparts rectilinear movement to a slide 16 which has riveted to it a double spring pawl 25 the ends 26, 27 of which step-on a ratchet 21 which drives the barrel ratchet 28 through a pinion 22. The slide 16 has at its ends slots 17, 18, which embrace sleeves 19, 20 respectively, carried by the shell 1 to guide the slide during its movement. The sleeves 19, 20 may carry rollers to reduce the friction between the sleeves and the slots 17, 18. The barrel ratchet 28 is connected to the barrel spindle by an adjustable friction device, Fig. 2 (not shown), so that overwinding is prevented. In a modification, Fig. 4 (not shown), the slide 16 is reduced in size and only extends to the right of the roller by which it is moved. In another example, Fig. 5, the slide is replaced by a ring 16a to which two pawls 26, 27 are fixed.