GB604034A - Improvements in watch winding device - Google Patents

Abstract

604,034. Winding mechanism. HILL, C., and JOHNS, C. K. Nov. 21, 1945, No. 31373. Convention date, Nov. 27, 1944. [Class 139] A watch winding device comprises in combination with the crown forming a driving element, a driven member having a stem for attachment to the winding shaft of the watch, and a friction member in driving relation with the crown and in frictional engagement with the driven member, both of said members being housed in the crown. As shown in Fig. 1 the winding device comprises a plate 13 which rests on the bottom of a crown 22 and has a stem 11 which is screwed on the winding shaft 10 of the watch. The driven plate 13 has, projecting therefrom, one or more studs 14 which engage with corresponding holes or depressions 15 in a domed friction disc 16 which is in frictional engagement with the plate 13 and is attached to a driving plate 24 which is fixed to the crown 22 knurled at 26. In operation the crown 22 is rotated and this rotation is transferred by way of driving plate 24, friction disc 16, driven plate 13 to the winding shaft 10 so winding the mainspring. When the mainspring is fully wound continued rotation of the crown 22 results in the friction disc slipping over the plate 13 and an audible warning is given by the " clicking " action of the projections 14 in the holes or depressions 15. It is obvious that the friction area of the disc 16, i.e. the area in contact with the plate 13, depends on the thickness of plate used, Fig. 7. In another embodiment, Fig. 3, the crown 35 is turned the other way up and the driven plate 41 is supported by a keeper plate 37 which is a force fit in the open end 36 of the crown 35. The friction disc 42 is attached directly to the crown 35 and no driving plate is used. In another modification, Fig. 6, the friction disc 50 has two small horizontal projections 48a which are loosely received by two vertical channels in the crown. In still a further modification, Fig. 8, the friction disc is replaced by a substantially circular wire spring 66 which surrounds the driven plate 63 and whose ends are held in openings 67 of the crown. The plate 63 has two straight sides and two curved sides as shown to allow for slipping when the mainspring is fully wound.