Patent ID: 7059453

Claim:
An electromagnetic brake interposed between a fixed housing and a rotating member at least partially accommodated in said fixed housing, comprising: a multiplate brake mechanism having a plurality of brake plates mounted on said fixed housing and a plurality of brake discs mounted on said rotating member so as to be arranged in alternate relationship with said brake plates; a ringlike core member fixed in said fixed housing, said ringlike core member having an annular groove and a first tapering surface inclined a first angle with respect to the axis of said ringlike core member; an annular exciting coil accommodated in said annular groove of said ringlike core member; a ringlike armature member having an axial length and arranged radially outside of said ringlike core member along the entire axial length of the ringlike armature member, said ringlike armature member having a second tapering surface complementary in shape to said first tapering surface, said second tapering surface being opposed to said first tapering surface; a first annular restriction member provided between the outer circumferential surface of said ringlike core member and the inner circumferential surface of said ringlike armature member at a position adjacent to said first and second tapering surfaces, said first annular restriction member being a ring and resting radial movement of said ringlike armature member; and a cylindrical pressure member movable in a direction of pressing said multiplate brake mechanism, said cylindrical pressure member having a first end fixed to an outer circumferential portion of said ringlike armature member and a second end engaged with said multiplate brake mechanism.