Power clutch for the main spring of watch movements and the like

• Main Author: FIECHTER RENE A
• Format: Patent
• Language: English
• Published: 04.08.1964
• Subjects: BLASTING; BRAKES; CLUTCHES; COUPLINGS FOR TRANSMITTING ROTATION; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; HOROLOGY; LIGHTING; MECHANICAL ENGINEERING; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; MECHANICALLY-DRIVEN CLOCKS OR WATCHES; PHYSICS; THERMAL INSULATION IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS; WEAPONS

955,318. One-way acting friction devices; lubricating. INTERNATIONAL MICROMECHANISMS CORPORATION. Feb. 27, 1962 [Feb. 27, 1961], No. 7710/62. Headings F2A and F2E. [Also in Division G3] A coil spring driven mechanism (for example a watch) includes a coil spring 2 fixed at one end to an arbor 3 to which is secured a rotatable friction element formed by a special ratchet wheel 7, a fixed second friction element formed by a cam and plate assembly 13, 14 and ball or roller mechanisms 18 movable into and of wedging relationship to relatively inclined surfaces according to the direction of rotation of the ratchet wheel 7. The watch movement shown in Figs. 1 and 2 shows a ratchet wheel 7 associated with the arbor of the barrel 1 containing the main spring 2, a crown wheel 11 and the centre pinion portion 4 of the watch movement to eliminate the customary click spring arrangement and replace it with a smoothly operating brake system of the above kind whereby the main spring may be prevented from being overwound and may be released from the final winding tension. In operation, application of a winding force to the crown wheel 11 in the direction of the arrow W1 will rotate the special ratchet wheel 7 in the direction of the arrow W11, during which operation the rollers 18 will tend to move freely to the positions indicated by the full lines in Fig. 1. When the application of the winding force ceases either during winding or when the spring 2 has reached its fully wound position, the spring ratchet wheel 7 will rotate in the reverse direction BL and will move one or more of the rollers 18 towards the cam surface portion 1611 where each roller will become wedged between its associated portion 16 and the wall 9 as indicated in the broken lines in Fig. 1, the reverse motion of the ratchet thus being arrested. Instead of the roller braking action being radial the frictional action may be effected in an axial direction by means of the alternative embodiment shown in Figs. 4 and 5 (not shown). A further embodiment (not shown) describes an arrangement where the cam plate, ratchet wheel and rollers are in a sub-assembly which can be handled as a unit. The rollers used in the above mechanism may be constructed such as to retain adequate quantities of lubricant for long periods of time. This is achieved by means of the arrangements shown in Figs. 14-16 inclusive wherein the interfaces between parts of the brake roller provide capillary or retaining areas from which oil will circulate to adjacent surfaces by centrifugal action.