GB285838A - Improvements relating to winding up mechanism for clocks - Google Patents

Abstract

285,838. Meier, K. H., and Huessy, W. Feb. 22, 1927, [Convention date]. Winding-apparatus; overwinding, preventing.- A clock weight is wound up through differential gearing, a part of which is held by a pawl, the weight when it reaches a certain height releasing the pawl to prevent overwinding, the differential thereafter absorbing the excess power. The source of power may be continuous or non-uniform; for example, expansion of a fluid under changes of atmospheric temperature may be used to operate a plunger. On its working stroke, the plunger pulls on a strap 5 to rotate a pulley 4 to which is fixed the inner end of a spring 3, the other end of the spring being attached to a casing 2 rigid with the stationary plate 1. This stresses the spring 3 and a wheel 10 rigid with the pulley 4 rotates a pawl 11 and a wheel 12 so that a wheel 13 fast on a shaft 15 is rotated. Carried by this shaft 15 are two wheels 18, 19 meshing with wheels 16, 17 which are loose on the shaft. Rigid with the wheel 17 is a pulley 24 carrying a cord 25, and a ratchet wheel 28, which, with a pawl 29, ensures that pulley 24 rotates only in one direction. Rigid with the wheel 16 is a wheel 20 gearing with wheels 32, 33 of which the latter may be arrested by a pawl 21 on a double bell crank lever 23, 30 pivoted at 22. The cord 25 supports the driving weight 26, and a counterweight 27 and passes over a pulley 34 which is fixed on the main driving arbor of the clock. When the pawl 21 engages the wheel 33 each working stroke of the plunger stresses the spring 3 and rotates wheels 12, 13, &c. so that the differential rotates the pulley 24 and winds up the weight 26. At each return stroke of the plunger spring 3 is unstressed and pawl 11 rides over the wheel 10. When the weight 26 reaches a certain predetermined height it raises the lever 30, 23 and removes the pawl 21, preventing overwinding.