Abstract: A spring-set, electromagnetically released brake that requires a relatively small amount of current to release is provided. The brake includes a magnet shell disposed about a first axis. The shell includes a radially outwardly extending pole. The brake also includes an armature disposed radially outwardly of the pole and pivotable at a first axial end and a first engagement element, such as a brake shoe, coupled to the armature proximate a second axial end of the armature. The brake further includes a spring disposed about the pole. The spring biases the armature radially outwardly to urge the first engagement element towards a second engagement element such as a friction surface in a brake drum. Finally, the brake includes a coil disposed about the pole and means for selectively energizing the coil to urge the armature radially inwardly and the first engagement element away from the second engagement element. A bobbin for use in the brake is also provided.

Abstract: A wrap spring operating mechanism for use in a random start/stop clutch, brake, or combined clutch/brake assembly limits the rate of acceleration or deceleration of the second member relative to the first member when the assembly is engaged. The assembly includes a first member, a second member, and a helical spring wrapped about adjacent portions of the first and second members. An annular control collar is disposed circumferentially about portions of the first and second members. The wrap spring has a first end that is connected to the first member and a second end that is connected to the control collar. An annular armature is connected to the control collar for rotational movement therewith and for relative axial movement. An annular rotor is disposed circumferentially about and connected to the second member. An annular friction ring is disposed within a recess formed in the rotor. The friction ring is formed from a material having a relatively low coefficient of friction, preferably about 0.

Abstract: A mounting system for attaching a clutch assembly to a base structure includes a support member, a clutch assembly mounted on the support member, the clutch assembly having a clutch with an axis generally normal to the support member, a bearing assembly mounted on the support member, and a fastener attached to the base structure and extending through the bearing assembly to prevent rotation of the support member with respect to the axis of the clutch, where the bearing assembly enables relative movement of the support member away from the plane of the base structure.

Abstract: A solenoid for controlling the engagement and disengagement of a wrap spring clutch includes an electromagnetic coil having a core member disposed adjacent one axial end thereof. An armature is provided within the electromagnetic coil for selective axial movement in response to the energization and deenergization of the electromagnetic coil. The armature is connected to an actuator for the wrap spring clutch such that movement of the armature controls the engagement and disengagement thereof. The core member and the armature are both formed from relatively soft, magnetically permeable materials. A flux breaker is disposed within the electromagnetic coil between one axial end of the armature and the core member. The flux breaker is formed from a relatively hard, non-magnetically permeable material, such as stainless steel. The flux breaker prevents the armature from contacting the core member when attracted thereto by energization of the electromagnetic coil.

Abstract: The tangs of the clutch and brake springs of a wrap spring clutch/brake unit are connected to separate sleeves which form the control collar of the unit. The sleeves are normally coupled for rotation in unison by an internally splined ring which may be slid to a released position permitting relative rotation of the sleeves for purposes of adjusting the torsional differential of the springs.