Abstract: A rotational coupling device for use as a clutch and/or brake is provided having a modular construction enabling relatively easy variation of braking torque and having improved magnetic efficiency during brake engagement and release. The device includes one or more brake modules attached to a mounting bracket to vary braking torque. The brake modules include brake poles axially aligned with one portion of an armature. Permanent magnets are contained in one of the brake pole and the armature and axially aligned with the other providing a strong magnetic circuit. The mounting bracket is axially aligned with another portion of the armature, radially outward of the portion aligned with the brake pole. At least one of the mounting bracket and the aligned portion of the armature has a high magnetic reluctance providing a flux busting gap in the magnetic circuit that allows easier release of the brake.

Abstract: A rotational coupling device for use as a clutch and/or brake is provided having improved magnetic efficiency and structural integrity. An electrical conduction assembly is disposed within a field shell between radially spaced inner and outer poles of the field shell. The assembly includes a conductor disposed within a shell having a radially extending flange that is disposed proximate the outer pole of the field shell and that is affixed to the field shell at a plurality of points.

Abstract: A rotational coupling device for use as a clutch and/or brake is provided having improved magnetic efficiency and structural integrity. A field shell and a rotor of the device each define radially spaced, axially extending inner and outer poles. The inner pole of the rotor is disposed radially outwardly of the inner pole of the field shell resulting in improved magnetic efficiency.

Abstract: A rotational coupling device for use as a clutch and/or brake is provided having improved magnetic efficiency and structural integrity. A permanent magnet is coupled to one of a brake plate and an armature and axially aligned with a portion of the other for improved braking performance.

Abstract: A clutch/brake assembly for selectively connecting a source of rotational power to a driven device includes an input hub and a flange secured to the input hub for rotation therewith. An output hub is journalled within the clutch/brake assembly for rotation relative to the input hub. One or more outwardly extending bosses are formed on the outer surface of the output hub. A friction plate is disposed about the input hub between the lower surface of the flange and the upper surface of the output hub. A ring of friction material is secured to the upper surface of the friction plate adjacent to the lower surface of the flange. The friction plate is connected to the output hub for rotation therewith and for axial movement relative thereto. To accomplish this, the peripheral edge of the friction plate has one or more axially extending finger portions formed integrally therewith.

Abstract: A rotor for a six-pole electromagnetic clutch includes an outer pole ring and an axially facing disc. The disc is formed with two circumferentially extending and radially spaced rows of circumferentially spaced slots, there being short circumferentially extending bridges between adjacent slots in each row. To strengthen the bridges against failure under high load and heavy wear conditions, a stainless steel reinforcing ring is brazed to the outer pole ring and the disc and transmits torque between the two. The outer edge of the disc thus may be spaced radially inwardly from the outer pole ring to establish an annular air gap which coacts with the two rows of slots to enable the rotor to possess the requisite magnetic characteristics to function in a six-pole clutch.

Abstract: The clutch includes an input hub keyed to a drive shaft, a spacer telescoped into and keyed to the input hub, a bearing telescoped over and supported radially on the spacer, and an output member supported by the bearing. A bolt is threaded into the drive shaft and, when tightened, causes the bearing to be clamped axially between the spacer and the input hub. The spacer is formed with flats adapted to be engaged by a wrench in order to prevent the spacer, the input hub and the drive shaft from turning when the bolt is tightened.

Abstract: Energization of an electric coil produces flux for attracting an armature of a clutch into engagement with a rotor in order to couple an input shaft to an output pulley. When the coil is de-energized, two angularly spaced permanent magnets pull the armature away from the rotor and into engagement with fixed pole pieces which cause a braking torque to be applied to the output pulley. The magnets are located closely adjacent one another and only along a short arc of the armature in order to enable the flux of the coil to overcome the flux of the magnets and effect easy release of the brake and engagement of the clutch when the coil is energized.

Abstract: A clutch/brake unit especially adapted for use with a walk-behind lawn mower and having a braking element which applies a brake and disengages a clutch when shifted axially in response to turning of a rotary actuator in one direction. A single anti-rotation bolt extends between the braking element and the engine of the mower to prevent rotation of the braking element when the brake is applied. Angularly spaced springs urge the braking element axially toward the rotary actuator and are located above the actuator so as to be shielded from lawn trash.

Abstract: A magnet assembly is made up by a plurality of magnet modules each having a permanent magnet adapted to attract a rotatable armature into engagement with the pole pieces of the module. Each module also includes an electromagnetic coil having an axis disposed perpendicular to the pole pieces. When energized, the coil produces flux which causes the permanent magnet flux to bypass the armature and enable release of the armature from the pole pieces.