Abstract: A wear ring that surrounds a friction disk to improve the life and performance of a clutch. The wear ring may further facilitate braking action. A hub retains a helical spring that wraps down upon the wear ring to actuate the clutch. The helical spring is at least partially retained by a lip formed on the hub.

Abstract: An electromagnetic disk brake is compact, self-sealing, self-contained, has relatively few components, and is relatively easy to fabricate and to install when compared to traditional electromagnetic disk brakes. Self-containment and self-sealing are achieved by providing a skirt on the field cup that extends over the remaining moving components of the brake and that is attached, preferably by a press-fit, to a reaction plate at the inner end of the brake. The need for stand-offs to set the air gap of the brake can be eliminated by suitable control of the press-fitting of the field cup onto the reaction plate. For electric motor braking applications, the reaction plate can form the endbell of the electric motor, thereby combining the endbell, mounting plate and reaction plate in a single plate. Simplicity and ease of assembly of a spring-applied brake are enhanced further by employing a single compression spring at the center of the brake rather than a plurality of peripherally-spaced springs.

Abstract: A combination clutch and brake uses a helically wound spring attached to a pulley at one edge and magnetically drawn to a rotor at a second edge. In a relaxed state, the spring presses against an outer field cup locking the pulley against that cup. In a torsion state caused by the magnetic attraction between the rotor and the spring, the spring decreases in diameter to compress a frictional wedge inward against the pulley and rotor causing them to turn as one.

Abstract: A multiple plate clutch/brake employs a single electromagnet coil to attract an elongate cylindrical armature to compress a series of non-ferromagnetic friction plates alternately joined to one of two independently rotatable shafts. The armature joins one set of friction plates to its shaft for torsional but not axial forces. The compression of the friction plates by the armature transmits torque between the shafts rather than frictional contact by the armature itself. The magnetic path to the armature may pass through two axial gaps to provide a net axial force on the armature. A portion of the magnetic path is provided by one of the shafts.

Abstract: An armature assembly in an electromagnetically actuated braking mechanism and including a circular armature plate having a central opening defined by a circumaxial series of radially inwardly extending armature teeth. The inner ends of the armature teeth cooperate to define a coaxial crest circle. A plastic hub, molded in place on the armature plate, substantially encapsulates the armature teeth and has a coaxial central opening defined by a circumaxial series of spline teeth which define a root circle having a diameter greater than the diameter of the crest circle. Equiangularly spaced fan blades integrally connected to the central portion of the hub project radially outwardly therefrom adjacent one face of the armature plate.