Spring-actuated electromagnetic brake with noise suppressing device

A spring-actuated electromagnetic brake comprising:

• a stationary field having an electromagnetic coil embedded therein for magnetizing the field;
• a brake plate mounted on a rotating shaft for co-rotation with said rotating shaft;
• an armature disposed between said field and said brake plate and movable only in the axial direction of the rotating shaft;
• a brake spring urging said armature against said brake plate to normally hold said brake in the engaged state;
• and
• a noise-suppressing device for suppressing a striking noise emitted when said armature is attracted onto said field to release the brake when said electromagnetic coil is excited to magnetize said field, wherein
• said field and said armature having opposed surfaces with a plurality of finite recesses formed in one of said opposed surfaces;
• said noise-suppressing device is a plurality of hemispherical elastic members disposed in said plurality of finite recesses, and
• said hemispherical elastic members each have a flat circular face seated in the bottom of one of said finite recesses and a hemispherical surface which, when the brake is in the engaged state, projects from said one of said recesses and is in contact with the other of said two opposed surfaces, said hemispherical surface adapted to deform as a whole to become a flattened shape.