Pulse generator for variable-speed drives

摘要

A pulse generator of variable-speed drives, particularly sewing machine drives having a main rotatable shaft and a housing comprising a casing defining an inner space connected to the sewing machine housing, a generator shaft rotatable and synchronous with the main shaft and mounted for rotation in the casing, a pulse disc with light-dark zones connected to the shaft and rotatable within the inner space of the casing, a light transmitting module and a light receiving module connected to the casing, the casing including bearing surfaces on either side of the disc bearing against and bearing surfaces of the shaft for supporting the pulse disc for rotation. Bearing surfaces provide a seal against stray light and dust and the like and also accurately center and support the pulse disc.