Pulse generator for sewing machines

In a sewing machine which comprises a machine housing, a main shaft rotatably mounted on the machine housing, a needle bar swingably mounted and vertically reciprocated by the main shaft, a feeding device operated in timed relation with the needle bar, first electrically operated means for controlling the lateral movement of the needle bar, and second electrically operated means for controlling the movement of the feeding device, a pulse-generating system operative for generating in synchronism with rotation of the main shaft pulses controlling the operation of the first and second electrically operated means, the pulse-generating system comprising two rotational parts, two pulse-generating devices, each pulse-generating device sensing the presence and absence of a respective one of the two rotational parts and generating pulses in correspondence thereto, each rotational part having an axial extension, and furthermore including a mounting ring encircling the main shaft and receiving the axial extensions of the two rotational parts and means securing the mounting ring and thereby the two rotational parts to the main shaft.