Abstract: An electromagnetic spring clutch has an armature (40) which can be moved to and from in the axial direction thereof and cannot be rotated on the axis, and which is biased by a spring (46), and a coil spring (36) which covers over outer faces of a master driving axle (30) and a slave driving axle (34) and which is capable of being wound tightly in the rotational direction of the master driving axle (30). When an electromagnetic coil (20) is not energized, an engagement section (44a) at the end of the armature (40) and a hook (38) of the coil spring (36) are engaged to expand the inner diameter of the coil spring (36) and disconnect the master driving axle (30) and the slave driving axle (34).

Abstract: The present invention relates to an electromagnetic spring clutch. A conventional field core is formed in a bottomed cylindrical shape, so manufacturing such a field core is troublesome and uneconomical. When a through-hole through which shafts are inserted is provided in one or both of vertical walls of a U-shaped plate, a field core is provided simply and inexpensively.

Abstract: In order to simplify the structure of the armature of an electromagnetic spring clutch and to lower the raw material cost, the armature is cylindrical and the field core is composed of a core section with a U-shaped bracket section having open sides and an open end and a yoke section fixed to the open end of the bracket section and having a through-hole in its middle in which the armature is inserted.