Overmolded clock wheel i.e. escape wheel, for use in clock escapement mechanism of clockwork of timepiece, has metal washer threaded on/secured to shaft, where wheel is molded by injection of plastic material on washer

摘要

The wheel (1) has a metal washer (3) threaded on or secured to a shaft (2), where the wheel is molded by injection of plastic material on the washer. The washer has a planar surface (4) forming a bearing and sealing surface for sealing engagement with an injection mold used to produce molding. A pinion (5) is mounted coaxial with the shaft and integral with the shaft. Toothing of the pinion extends through the entire length of the pinion. The pinion is mounted on the washer or secured with the washer. The washer is perforated to reduce inertia relative to a pivot axis (D). An independent claim is also included for a method of manufacturing an overmolded clock wheel.