Abstract: A rotational coupling includes input and output hubs disposed about a rotational axis and an attachment ring disposed about the axis on one side of the input hub opposite the output hub. A flexible, multi-coil body such as a cable is disposed radially outwardly of the input and output hubs and couples the hubs together for rotation upon rotation of the input hub in one rotational direction. The body has ends coupled to the output hub and attachment ring. A torque limiter includes a torque transmission plate configured to rotate with the input hub and an armature plate fixed against rotation. The torque transmission plate and armature plate are configured to move axially together along the axis of rotation. An electromagnet disposed on one side of the torque limiter opposite the input hub attracts the plates in a second axial direction away from the attachment ring when energized.

Abstract: A rotational coupling is provided. The coupling includes first and second hubs disposed about an axis of rotation. A wrap spring is disposed radially outwardly of the hubs and rotatably couples the hubs upon rotation of the first hub in a first rotational direction. A spring actuation member is configured for rotation about the axis and coupled to one end of the wrap spring. The opposite end of the wrap spring is coupled to the second hub. An actuator is configured to selectively stop rotation of the spring actuation member and the second hub in the first rotational direction and cause rotation of the spring actuation member in a second rotational direction to thereby unwrap the wrap spring. The rotational coupling therefore facilitates disengagement of the wrap spring from the first hub during release of the coupling to prevent undue noise and vibration and reduce wear.

Abstract: A rotational coupling is provided. The coupling includes first and second hubs disposed about an axis of rotation. The coupling further includes a wrap spring engaging the first hub and disposed radially outwardly of the second hub. The wrap spring is configured to couple the first and second hubs together for rotation during rotation of the first hub in a first rotational direction. The coupling may include one or more shoes disposed radially between the second hub and the wrap spring and springs for biasing the shoes radially outwardly from the second hub. By urging the wrap spring away from the second hub, quick and complete release of the wrap spring occurs even where the difference in rotational speed between the hubs during clutch disengagement is low.

Abstract: A rotational coupling is provided. The coupling includes first and second hubs disposed about an axis of rotation. A wrap spring is disposed radially outwardly of the hubs and rotatably couples the hubs upon rotation of the first hub in a first rotational direction. A spring actuation member is configured for rotation about the axis and coupled to one end of the wrap spring. The opposite end of the wrap spring is coupled to the second hub. An actuator is configured to selectively stop rotation of the spring actuation member and the second hub in the first rotational direction and cause rotation of the spring actuation member in a second rotational direction to thereby unwrap the wrap spring. The rotational coupling therefore facilitates disengagement of the wrap spring from the first hub during release of the coupling to prevent undue noise and vibration and reduce wear.

Abstract: The brake assembly includes a motor shaft connected to a friction disk assembly. Springs housed in a field cup assembly, frictionally link a clapper plate assembly and friction disk assembly against a mounting plate to activate the brake. To disengage the brake, the field cup assembly magnetically attracts the clapper plate thereto and the friction disk assembly is free to rotate. For manual release, rotation of a lever arm against a reaction plate compresses a wave spring to generate an opposing force which overcomes the springs, thereby forcing the clapper plate assembly away from the friction disk assembly to allow rotation thereof.

Abstract: The brake includes a housing for mounting and a disc assembly. The disc assembly engages a drive shaft for rotation therewith. A flange on the disc assembly receives a first ring and a second ring, each ring is slideably engaged to the flange for axial motion. Release plates adjacent to the second ring are free to move in an axial direction. A field cup has springs to bias the release plates against the second ring and o-rings to facilitate quiet operation of the elevator car brake. When no current flows through the coil, the release plates are biased against the second ring. Thus, the second ring engages the friction surface of the housing to park and hold the drive shaft. When current flows through the coil, the first and second release plates are drawn to the field cup, overcome the bias force of the springs and compress the o-rings.

Abstract: A clamping system is disclosed and includes a hollow shaft for interlocking with a shaft. The hollow shaft is integral with a device so that when the hollow shaft and the shaft are coupled, the device rotates therewith. The hollow shaft has slots to allow a two-piece clamping mechanism to simultaneously contact the hollow shaft and the shaft to accomplish the desired coupling. The clamping mechanism includes two shells with mating surfaces and wing portions for generating compressive force to couple the mating surfaces to the hollow shaft and the shaft.

Abstract: A soft action clutch uses a helical spring attached to a pulley at one end and free at the other end. In a relaxed state, preferably, the helical spring presses outwardly pushing a brake pad assembly against a fixed outer field cup braking the pulley. To serve as a clutch, a rotor has a pole face to magnetically draw the helical spring towards it. The resulting friction between the rotor and helical spring causes the spring to wrap down on a spring loaded friction disk. The wrap down compresses the friction disk radially, creating two frictional links from the friction disk to the rotor and the pulley, respectively.

Abstract: An electromagnetic brake includes an improved friction disk that has at least one friction surface formed entirely from a rubber material such as a styrene butadiene rubber material. The rubber material 1) has a high coefficient of friction, 2) conforms to the shape of the mating braking surfaces, 3) is dimensionally stable so as not to unnecessarily widen the air gap of the brake when the brake is applied, and 4) exhibits acceptable wear characteristics. The rubber material also preferably does not exhibit a sharp reduction in coefficient of static friction when it is heated, e.g., due to friction from its mating surfaces and/or due to heat transfer from the electric motor or other braked element. The resultant brake is relatively light-weight, compact, and inexpensive. It is particularly well-suited for use as a static, park-and-hold brake for an electric motor or the like.

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: A battery powered line trimmer possessing a relatively high ratio of mass moment of inertia about a vertical axis extending through its center of gravity to mass. The device comprising a motor and head assembly at the forward end and a rechargeable battery pack at the rearward end of a support shaft. Also, adjustable handles, for supporting the line trimmer, attached about either side of the center of gravity.

Abstract: A line trimmer head 10 for a vegetation cutter having an automatic line feed mechanism which replenishes the line 19 as a result of changes in centrifugal force. The line trimmer head 10 comprises a reel housing 14 which rotates with a shaft 12. A spool 18 containing a supply of line 19 is located within the housing 14. An indexer cam 16 is journaled on the shaft 12 and is axially and rotatably shiftable with respect to the shaft 12. The indexer cam 16 is periodically axially shifted and rotated by a reduction in the centrifugal force applied by the line 19 to the spool 18. A spring 20 is provided to bias the indexer cam 16 axially relative to the housing 14 away from an interlocked posiiton. In the interlocked position, the indexer cam 16 and housing 14 are interlocked together so that the spool 18, indexer cam 16, housing 14 and shaft 12 rotate together.

Abstract: An electromagnetic jaw clutch has interengageable teeth with gaps between them to facilitate engaging the clutch when there is some relative rotation between these teeth. The teeth are defined on one hub and on the armature. The second hub is plastic and a spring pulls the armature toward this second hub to disengage the clutch. The spring may be integrally formed with the plastic second hub.

Abstract: A piston assembly is disclosed having a wrist pin for pivotably attaching a connecting rod to a piston for use in an internal combustion engine. The wrist pin is formed from an elongated circular cylindrical body having a pair of deformable sections formed adjacent each end and a relatively hard middle section therebetween. The wrist pin is sized for insertion along a longitudinal axis defined by a pair of coaxially aligned, spaced apart bores formed in diametrically opposed portions of the piston. The deformable end sections are adapted to be deformed sufficiently to engage the bores of the piston to limit the axial movement therebetween. The relatively hard middle section spans between the bores in the piston for pivotably engaging one end of the connection rod.

Abstract: An automatic line trimmer head 10 including a housing 11 containing a rotor 12 which controls rotation of a spool 16 relative to the housing in a stepwise fashion which is actuated by centrifugal force. Centrifugal force acts upon a radially expansible annular member 14 which is disposed between the housing 11 and the rotor 12. The spool 16 contains a supply of line 18 and is attached to the rotor 12 for rotation with the rotor. A shaft extends through the housing 10, rotor 12 and spool 16. The rotor 12 is biased by a helical spring 24 toward an upper plane of rotation. The radially expandable annular member 14 shifts the rotor 12 to a lower plane when centrifugal force expands the annular member 14. Teeth 54 extending radially outwardly from an outer edge 56 of a circular disk portion 50 of the rotor 12 contact an upper set of stop blocks when the circular disk portion 50 is in the upper plane. The teeth 54 contact a lower set of stop blocks 42 when the circular disk portion 50 is in the lower plane.