Abstract: A braking system for a vehicle has a stepper motor which controls the application of friction elements to a rotating part such as a brake drum. A control circuit controls the motor so that an output member is positioned by the motor in accordance with a variable demand signal. In one application, the control circuit receives a brake pressure signal from a transducer and controls the motor so as to compensate automatically for brake wear. In another application, the motor controls a debooster of an antilock brake system. The system also may include means for operating a parking brake.

Abstract: A spray-resistant water shield is formed for an electric motor by a water shield of a plastics or elastomeric material. This water shield has a conical edge with a periphery which seals against the exterior surface of an end shield, as part of the frame of the motor. A spring in the motor urges the rotor to a position of displacement relative to the stator during de-energization of the motor so that the water spray seal is effected. When the motor is energized, the rotor tends to align with the stator and the water shield moves away from its sealed condition with the motor frame to establish normal running conditions of the motor.

Abstract: An electromagnetic device such as an electromagnetic brake or an electromagnetic coupling comprises an electromagnet, at least two parts arranged so that, when the electromagnet is switched on, a magnetic flux extends through the parts. Formations reducing residual magnetism in the parts, including a plurality of gaps formed as slots, are provided in at least one of the parts, such that this part remains a one-piece member.

Abstract: An electric motor and brake comprises a stator, a rotor, a rotatable brake member and a fixed brake member, the rotor carrying a magnetic actuator at one of its ends. A coupling mechanism couples the rotatable brake member to the motor to rotate with the rotor but to be axially displaceable with respect thereto, and the rotatable brake member is made at least in part of magnetic material, so that it is attracted axially toward the magnetic actuator and away from the fixed brake member by the magnetic field produced by current flowing through the rotor. A spring is provided for urging the rotatable brake member away from the actuator and into engagement with the fixed brake member. The magnetic actuator is U-shaped and opened at one side, and the stator is in line at both its ends with the rotor.

Abstract: A high performance, lightweight and low cost dynamically controlled motor 10 is disclosed wherein the position control of the motor is accomplished by the use of an electronic braking apparatus 20. The dynamically controlled motor 10 of the present invention includes a standard electric motor 15 controlled by the electronic braking apparatus 20. The electric braking apparatus 20 includes a piezoelectric transducer 50 which can be activated to provide a braking force to the rotor 35. The rotor 35 is rotated to the desired stopping location, then the electronic braking apparatus 20 is activated by activating the piezoelectric transducer 50. The rotor 35 can thereby be held at the desired position.

Abstract: The rotor is held on a shaft by means of a membrane providing an easy resilient deflection in axial direction and being stiff for torque transmission in azimuthal direction. The membrane is star-shaped, or has spiral arms or is of polygonal configuration. A membrane carrier is connected to a central part of the membrane or to polygon corner points; the rotor, through a sleeve extension of a short circuiting ring is connected to peripheral points of the membrane. The carrier is splined to or slip friction coupled to the shaft.

Abstract: The object of the process is to obtain an intermediate short-circuiting ring in a squirrel cage rotor by filling. It makes use of the technique consisting in automatically cutting out and assembling rotor laminations by means of a follow-on machine in which the laminations are cut out from a strip, rotated through a determined angle and provided with half-cutouts for their assembly in a packet. The process consists in eliminating at least one tooth in every two from the laminations whose position in the packet corresponds to the situation of the intermediate short-circuiting ring, and turning these laminations through an angle such that when filling is effected a continuous annular zone of nonmagnetic material is obtained.

Abstract: An electromagnetic brake is disclosed in which a brake spring applies compressive force to an armature plate and friction discs to apply the brake. Electrical energization of a coil creates an electromagnetic force on the armature plate in a direction opposite to the braking force on the spring to move the armature plate and spring away from the friction discs and release the brake. A brake adjustment and release mechanism threadably rotates a disc against the spring to increase its compressive force against the armature plate and friction discs to adjust the spring braking force when the discs wear. The mechanism also can be rotated against a cam surface to move the armature in a direction away from the friction discs and against the spring to release the brake for purposes such as maintenance when the brake is not in normal operation.

Abstract: A disk brake motor comprises an electric motor having a housing, an electromagnet, at least one friction surface and a brake wheel which is in contact with the friction surface during braking, the brake wheel including an impeller for drawing in and impelling air so that the air flows tangentially of a surface of the electromagnet into the brake wheel and past the friction surface onto a surface of the housing of the electric motor.

Abstract: A brake mechanism is disclosed wherein a support lever is pivoted at a pivot end to a stationary bearing plate and is urged by a plurality of springs, which engage the support lever radially inwardly from its pivot end, toward the end plate to effect clamping of a rotatable friction disc between the end plate and a brake shoe disposed near the pivot end of the support lever. A solenoid has a plunger pivotally connected directly to a bracket end of the support lever adapted to overcome the forces applied by the springs and release the brake when the solenoid is energized. The springs apply pressure in close proximity to the pivot point and with the solenoid being disposed at the remote free end of the support lever, there are achieved greater mechanical advantages without the need for complicated linkage assemblies. The arrangement of parts is such that the solenoid mechanical advantage is substantially 7 to 1, while the spring-set mechanical advantage is approximately 7 1/2 to 1.

Abstract: An electromagnetic brake having brake shoes which are mounted immobile in circumferential direction with respect to a shaft, but are movable in radial direction. The brake shoes interact with a concentric ring-shaped brake stator having a toroid coil and a magnetizable ring housing that force the brake shoes in a radial direction opposite that of a radial force produced by a spring connected to the brake shoes, centrifical force, or a permanent magnet.

Abstract: A miniature generator includes a cup-shaped supporting shell for fixing a yoke assembly, which supporting shell includes a bearing for a rotary shaft of a permanent magnet rotor. The rotary shaft of the rotor is provided with a worm which drives a worm gear engaging with it.

Abstract: The invention concerns a frequency converter-controlled squirrel cage motor particularly for use in elevator operation. The motor's stator is mounted on a stationary axle and the rotor rotating around the stator has been rotatably carried on the same axle. On the outer periphery of the rotor a cylinder has been mounted, carrying rope grooves and a brake surface for the elevator's lifting ropes and brake.

Abstract: A friction braking system located entirely inside an induction motor of an appliance quickly stops rotation of the rotor in the appliance motor, for example such as a food processor, whenever the A.C. electrical power is turned off. Thus, rotation of any tool being operated in the appliance is quickly stopped, whenever the electrical power is interrupted. The rotor in the induction motor is axially slidably mounted on the motor shaft and is keyed to the shaft for permitting axial shifting displacement of the rotor relative to the stator while preventing any angular displacement of the rotor relative to the shaft. Consequently, the rotor and shaft always turn and stop as a function unit. A friction brake lining is affixed within the motor housing offset from the axis of the motor shaft as far as practicable. A disc brake mounted onto the rotor has an annular friction braking surface positioned for engagement against the brake lining.

Abstract: The present invention relates to an asynchronous motor having a squirrel-cage rotor, associated with a brake operating in the absence of current. The rotor comprises, at its two opposite ends, first and second short-circuiting rings and an intermediate short-circuiting ring, all three being made from non-magnetic material and being connected by longitudinal rotor windings. The intermediate ring extends radially from the outer diameter of the rotor as far as a cylindrical recess provided axially between the second ring and the intermediate ring. It is provided in order to separate a part of the rotor, intended to deflect the corresponding part of the radial stator field towards the moveable plate of the brake. This moveable plate has a radial face arranged opposite segments of magnetic material arranged radially between the periphery of the second ring and the outer diameter of the rotor. The second ring extends radially as far as the recess.

Abstract: A built-in wheel speed sensor structure having an internal gear-like sensor rotor integrally fixed to a tire and an electromagnetic car speed sensor fitted to an inner portion of a parking brake and facing the sensor rotor. The wheel speed sensor is supported by an anchor pin of the drum brake so that the sensor rotor may be positioned away from service holes for fastening bolts which have been bored into a brake drum.

Abstract: A low inertia, speed variable induction motor comprises a frame, a stator fixedly placed in the frame, a yoke fixedly placed in the frame in opposition to the stator with a predetermined gap and a cup-shaped rotor which is inserted into the gap and is fixedly mounted on an output shaft supported in the frame in a freely rotatable manner. Rotating magnetic field is produced in the gap by the stator and the yoke to generate a rotational torque of the cup-shaped rotor. The cup-shaped rotor is formed of a material or materials having a hysteresis characteristic and an eddy current producing characteristic to obtain a large torque.

Abstract: A rotational brake member controls the rotational velocity of an electric generator assembly housed within a projectile. The assembly includes an air-driven turbine and an electric generator. The brake member is affixed to the turbine which drives a rotatable element of the generator to produce electric power. The brake member is formed from an elastically deformable material and is adapted to contact the stationary surface proximate the periphery of the brake member at a predetermined angular velocity. In addition, a shock absorbing member formed from an inelastically deformable material is positioned to absorb shock to the turbine when the projectile is fired. Preferably, the generator further includes an elastomeric seat for biasing the turbine away from the shock absorbing member after the projectile has been fired.

Abstract: A back-stopping device rotor assembly is coupled to a motor shaft to rotate therewith and include a pair of L-shaped flyweights pivotably mounted to a channel crossbar, on respective sides of a motor shaft, which crossbar rotates at right angles to the shaft axis. The flyweights are pivotably mounted to the crossbar at points closer to their end facing the motor housing at positions regularly spaced from the shaft while extending parallel to the shaft, with the motor rotor at rest. A bracket mounted on the motor housing to one side of the shaft supports a stop relative to the shaft borne device rotor such that when the motor rotates at high acceleration in a first forward direction, the flyweights pivot during initial rotation to positions such that their ends proximate to the stops sweep through a stop recess and do not impact the stop. Low acceleration, backward rotation of the motor shaft up to a maximum of 180.degree.

Abstract: A hub and dynamo arrangement includes a wheel hub rotatable about the axis of a fixed shaft; a dynamo having an annular stator carried by the hub, an annular armature disposed radially inwardly of the stator and a current collector fixed to the armature for leading off current generated by the dynamo, the armature being mounted for rotation about the axis of the shaft independently of the hub; a control device for selectively arresting and permitting rotation of the armature about the axis of the shaft, whereby electric current is generated when the armature is arrested, the control device including a contact member mounted for radial movement relative to the axis of the shaft and mounted in a position such that the radial movement effects current-transmitting and rotation-locking engagement with the current collector; and an electrically-conducting, actuating wire attached to the contact member, both for transmitting current from the contact member, and for applying mechanical actuating force to the contact

Abstract: An actuator assembly has two actuators mounted back-to-back such that their actuator rods are displaced in opposite directions. Each actuator has a spring embracing the rod between two slidable collars. The spring urges the collars apart towards stops on the rod and stops on the actuator housing, so that, on failure of the actuator, the rod is displaced to a central position. The rod is driven by a motor which also rotates two discs of different diameters. Each disc has a notch in its edge which align only at the central position of the rod and allow a roller to drop into the notch. When the actuator fails, a solenoid releases a locking arm which engages the rollers, keeping them in the notches thereby preventing rotation of the discs and displacement of the rod.

Abstract: A spring engaged and magnetically disengaged disc brake for engaging two opposing flat surfaces of a rotating disc such as to decelerate the rotating disc. The brake device includes a frame mounted in a fixed position relative to the rotating disc and a pair of identical brake subassemblies interposed portions of the frame and each of the opposing flat surfaces of the rotating disc. Each of the brake subassemblies includes an electromagnet fixedly interconnected with the frame, an armature interposed the electromagnet and one of the flat surfaces of the rotating disc, a spring interposed the frame and the armature to bias the armature towards the rotating disc when the electromagnet is de-energized, and a brake lining interposed the armature and the rotating disc. The frame may be formed of two magnet bodies fixedly interconnected with each other or of a single U-shaped stamping.

Abstract: The motor has two motor flanges (1,2) which form the stator with stator magnets projecting axially inward from the inner sides (11,12) of the flanges, the magnets being distributed along a circle coaxial with the motor axis, and a slightly conical rotor (9) in the air space between opposing stator magnets (11,12). On the output side of one motor half, and facing outwardly, is an annular space defined by the stator magnet (11) on the output side of the motor flange (1). A blocking brake (18 to 23) is mounted in a space-saving manner, with the stationary half of the brake (18 to 21) placed in an opening made for it in the outer flange piece (18) in the motor flange (1) and attached to it. The rotating half of the brake (22,23) is attached to the motor shaft (6). In this way, the motor and friction brake form a compact structural unit whose dimensions are not greater than those of an ordinary motor housing.

Abstract: An object of the invention is to provide variable damping for resonant vibrations which may occur at different rotational speeds in the range of rpms in which a rotating machine is operated.A variable force damper in accordance with the invention includes a rotating mass (12) carried on a shaft (11) which is supported by a bearing (13) in a resilient cage (14). Cage (14) is attached to a support plate (15) whose rim extends into an annular groove in a housing (17).Variable damping is effected by tabs (18) of electrically conducting, non-magnetic material which extend radially from the cage (14). The tabs (18) at an index position lie between the pole faces of respective C-shaped magnets (19). The magnets (19) are attached by cantilever spring members (20) to the housing (17).By rotating the support plate (15) about the axis of shaft (11), the tabs (18) may be rotated through an angle 0 of about 40.degree. away from the index or 0.degree. position. At the 40.degree. position minimum damping is obtained.

Abstract: An electric motor having an electromagnetically operated clutch automatically engageable to lock the motor shaft against rotation in at least one direction. Embodiments are described in which interruption of the power to the motor causes engagement of the clutch and in which application of power to the motor causes disengagement of the clutch. Also disclosed is an automatic sliding door assembly operated by an electric motor having an electromagnetically operable clutch which is engaged on interruption of power to the motor to lock the motor shaft against rotation in one direction.

Abstract: The invention refers to a brake electrical asynchronous motor with short-circuited rotor and double drive, where its magnetic field simultaneously generates both the revolving torque on the rotor, and the electromagnetical force for deblocking the brake.The motor, according to the invention, is characterized by a constructive system with a normal stack of statoric sheets, elongated by a supplementary stack of statoric sheets, having the same cross-geometry as the normal stack of statoric sheets, with an excitation winding common to both, a normal stack of rotoric sheets with the cage rods elongated into the area from under the supplementary stack of statoric sheets, and separated by stacks of teeth between which are created slots with the same shape with those in the area of the normal stack of statoric sheets, but opened towards the inside and short-circuited through these openings by the short-circuiting ring, located in this area.

Abstract: A motor has an electromagnetic brake which is connected to the output shaft to brake the rotation of the output shaft, whereby the driving body can be forcibly braked with excellent stopping response.A fan for forcibly cooling the inside of the motor is enclosed in the casing, whereby temperature rises can be prevented by ventilation.A bracket for supporting the iron core of the brake coil is made of a non-magnetic material, whereby the leaked magnetic flux passing through the bearing fixed on the bracket can be prevented, and consequent damage to the bearing heated by the eddy current can be prevented.The stator can be a stator having windings used in a conventional induction motor, and the rotor is a cup type rotor having a simple structure extended in the axial direction. Accordingly, the structure is simple, and the size of the motor in the radial direction can be reduced.

Abstract: In an electromagnetic retarder armature rotor, comprising a disk (1) connected to a securing collar (2) by means of a ring of rams (4, 4.sub.1) forming ventilation fins, the largest diameter portions of these arms projecting axially from the disk and their tops being connected together by an annular flange (5) parallel to the disk, the assembly of the disk, the collar, the arms and the flange forming a single molded block, if we call D the outer diameter of the disk (1), a the axial distance between this disk (1) and the flange (5), b the radial width of this flange (5) and r the inner radius of said flange (5), the ratio Db/ar is between 10 and 30.

Abstract: An automatic brake control for rotary electric tools such as saws, drills, sanders, grinders and the like comprises a pair of spring biased brake shoes positioned about the periphery of the brake drum of an electric motor which drives the tools. The brake shoes are normally spring biased into engagement with the brake drum which is placed around the fan which in turn is pressed onto the armature shaft. Upon actuation of the motor, a cam element moves the brake shoes back from the drum and into an anchor recess at one end, permitting the motor to operate the tool. The cam element is actuated by a linkage coupled to the trigger through an intermediate pivot plate. When pressure is released on the trigger, the brake shoe springs take over snapping the shoes into contact with the drum and moving the linkage back to the starting position. This action immediately stops the tool and eliminates possible safety problems.

Abstract: The invention refers to a brake electrical asynchronous motor with short-circuit rotor and double drive, where its own magnetic field simultaneously generates both the revolving field on the rotor, and the electromagnetic force for deblocking the brake.

Abstract: A lead screw is threaded into a lead nut to move the lead nut one way or the other depending on the direction of rotation of the lead screw. The lead screw is held in an operative position by springs which prevent it from moving from its operative position until an excessive overload occurs. Braking disks are positioned on opposite sides of a sheave mounted on the lead screw. Abutments hold the braking disks spaced from the sheave to provide a small clearance when the shaft is in its operative position. When the shaft encounters an excessive overload, it will move axially from its operative position and its rotation will be stopped by one or the other of the braking disks. A yieldable support is provided for the braking disks. In one embodiment the yieldable support is a piston-cylinder assembly. In another embodiment it consists of a set of springs.

Abstract: A compactly sized spring-applied electromagnetically released radial face friction brake, with a ball-pocket torque booster producing increased torque capacity is disclosed. The friction brake is released by energization of an electromagnetic coil attracting an axially movable armature, which nullifies the spring operator force to release the brake. The friction brake includes a driving hub having a plurality of bosses which engage a plurality of slots in a rotatable member to be braked. Thus, the driving force from the hub is distributed to the rotatable member so that both brittle and nonbrittle friction materials can be used to form the rotatable member. In addition, a collar is provided to limit the axial movement between the armature and the stationary ferromagnetic housing which contains the electromagnetic coil therein. Thus, as the friction surface on the rotatable member wears away, the magnetic air gap cannot become so great as to prevent brake disengagement.

Abstract: To provide an indexed drive to a device such as a rotary switch having a detent mechanism, a three step-phase stepping motor is wound with only two of the phases (A, B) in its stator slots (S1-S24). Those slots (*) which would carry the third step-phase winding in a conventional machine are left empty. To index the drive from one detent position (I) to the next position (J), first the step-phase (A) and then the step-phase (B) are energized, to take the detent mechanism past its top dead center position (X). The drive then continues to the next position (J) under the detent force and its own inertia, while the step-phase (B) is kept energized to provide electrical retardation to prevent overshoot.

Abstract: A brake assembly includes a non-magnetic brake housing fixedly mounted to a motor shaft and a magnetic brake disc axially movable along the shaft in mechanically interlocked relationship with the brake housing between a braking position where it is attracted by an electromagnet against a fixed friction surface and a non-braking position into which it is biased by a pair of compression springs.

Abstract: An electric motor with automatically acting brake, which possesses a brake element including an armature plate and displaceable on the rotor shaft against a helical spring, and released by the magnetic field of the rotor. The brake element axially guides a disc possessing guide grooves situated between it and the armature plate. The inclined planes of the disc are facing towards the rotor and extending around the rotor shaft in the form of annular segments are disposed axially symmetrically on this disc, which are pressed by a prestressed spring bearing against the brake element onto a starting pin inserted into the rotor shaft.

Abstract: The friction face of an electromagnet is formed by a relatively thin sheet of friction material and by magnetic inserts which are secured to the friction material and which define the pole faces of the magnet. The friction face is adapted to be easily removed from the magnet and replaced with a new friction face when the friction face becomes worn.

Abstract: A starter motor wherein the driven shaft is provided with a brake arrangement including a brake disc carried by the shaft. First and second friction members are engageable with opposite faces of the brake disc respectively and a brake operating member is movable by return movement of the pinion assembly to cause relative movement of the first and second friction members to grip between them the brake disc, so generating a braking force.

Abstract: A compactly sized spring-applied electromagnetically released radial face friction brake, with a ball-pocket torque booster producing increased torque capacity. The friction brake is released by energization of an electromagnetic coil attracting an axially movable armature, which nullifies the spring operator force to release the brake. A fail safe electric motor brake application of the brake includes a friction surface mounted to the cooling fan rotated by the electric motor armature to aid in dissipating the heat energy developed in braking.

Abstract: A brake mechanism is disclosed wherein a support lever is pivoted at a pivot end to a stationary end plate and is urged by a spring, which engages the support lever at its free end, toward the end plate to effect clamping of a rotatable friction disc between a brake shoe and friction plates disposed near the pivot end of the support lever. A solenoid is mounted on the support lever and is connected to a cam pivoted to the end plate and adapted to contact the support lever near its free end to overcome the force of the spring and to release the brake when the solenoid is energized. The location of the spring and cam near the free end of the lever and the configuration of the lever provides mechanical advantages that permits the use of a smaller solenoid and spring. The arrangement of parts is such that the solenoid mechanical advantage is between approximately 24-32 to 1, depending upon the selected brake releasing clearance, while the spring mechanical advantage is approximately 81/2 to 1.

Abstract: An electric coupling and brake motor comprises a continuously rotating main or drive shaft of the motor and an output shaft coaxially therewith, on which a cylindrical coupling member is coaxially mounted for rotation therewith and axially immovable with respect thereto. A flywheel is mounted on the drive shaft for rotation therewith and axially movable with respect thereto and facing one of the end faces of the coupling member, and a brake abutment member is mounted in the motor housing movable only in axial direction toward and away from the other end face of the coupling member. The motor includes further electromagnet means for selectively moving the flywheel or the brake abutment member in axial direction into frictional engagement with the respective end face of the coupling member to rotate the output shaft together with the drive shaft or to hold the output shaft stationarily during rotation of the drive shaft.

Abstract: A linear induction motor includes one ferromagnetic member thereof which is movably resiliently mounted in the motor frame so as to move toward the stator in the motor whenever current is applied thereto. A portion of the armature in the motor extends between the resiliently movable member and the motor frame. When the motor is energized the armature is free to move between the ferromagnetic member and stator. When the motor is de-energized, the resiliently movable member is biased toward the motor frame and sandwiches the armature between the member and the frame so as to prevent the movement thereof. Reactivating the motor then attracts the movable member toward the stator and frees the armature.

Abstract: A hoist brake with an incremental self adjusting feature. The brake has interdigitated plates which will stop a driven shaft when engaged and allow the shaft to rotate when not engaged. The brake is normally biased into an engaged position and an electromagnet is provided to disengage the brake. A sensing apparatus is provided which measures the gap traversed by a portion of the brake when the brake is activated, the traverse indicating the amount of wear which has taken place since the last adjustment. When the amount of wear is greater than a predetermined amount, the distance between the electromagnet and associated plate on which it acts is incrementally reduced the next time the brake is activated to adjust the gap and insure continued proper performance.

Abstract: A brake for drive motors wherein a brake disk is adapted to be pressed against a stationary brake lining which is provided with a bead-like rim and which is held elastically both radially and axially via a molded rubber member having a profile which bears a mating relationship to the bead-like rim, thereby permitting the brake lining to be held by the member detentably in the manner of a snap connection. The brake is further provided with a brake disk ring which is firmly connected to the molded rubber member and which is adapted to be connected to a stationary member.

Abstract: A base yieldably supporting a frame, on which an electromagnetic assembly is mounted, is fixedly secured to a more massive body to which an armature is elastically connected by coupling springs. Limit switches control initiation and termination of a timer controlled cycle during which the electromagnetic assembly is energized to cause advancement of the armature under magnetic attraction followed in sequence by acceleration of the massive body and the frame under the urge of the elastically deformed springs.

Abstract: A brake apparatus is disclosed in which a rotary shaft coupled to a load to be rotated is rotatably supported by a plain bearing and a biasing device is located near the shaft to bias or move the shaft to the biasing device to applying braking force to the rotating load by the friction between the shaft and its bearing so as to stop the rotation of shaft and hence load.

Abstract: Rotatable discs are splined on a hub member and alternately arranged with stationary discs secured to the brake housing to form a brake disc assembly. The brake operator assembly is a combination electromagnet release, spring set assembly associated with a pressure plate and operative to selectively move the pressure plate into and out of engagement with the brake disc assembly for braking the assembly against and releasing the assembly for rotation. Primary torque springs are actuable, when the electromagnet is de-energized, for biasing the pressure plate into engagement with the brake disc assembly. Secondary torque springs are held against actuation to so bias the pressure plate by axially movable guide rods which include outer end portions engageable with outer fixed shoulders to hold the guide rods in a latched position. The secondary torque springs are actuated when the end portions of the guide rods are moved or cammed to an unlatched position, i.e. out of engagement with the shoulders.

Abstract: The present invention relates to hoisting mechanisms and can be utilized to utmost effectiveness in electric hoists. The hoisting mechanism is provided with a rope drum enclosed within a casing and a driving unit of which the motor is accommodated within the rope drum and operatively connected with a reducing gear and a brake. The housing of the motor on the brake side is arranged in supports permitting angular displacement of the output shaft of the driving unit relative to the axis of symmetry of the mechanism and adapted to transmit to the reaction torque to the casing. The drum has one end thereof mounted in a support, the other end of the drum having a flange pivotally supported by the output shaft of the reducing gear of which the input shaft is axially aligned with the output shaft. The disclosed construction enhances reliability and durability of the hoist, facilitates its assembling, operating and maintenance and improves the ergonomic characteristics of the mechanism.

Abstract: A brake mechanism for an electric motor used to drive a projection screen apparatus. The brake mechanism includes a first brake surface fixed to an exterior brake support about an end of the motor shaft projecting from the housing, a second brake surface adjustable on the shaft end and confronting the first brake surface, and a spring for normally urging the brake surfaces into engagement to prevent rotation of the shaft, and brake surfaces being urged apart and the action of the spring counteracted when the motor is operated as the rotor of the motor, which is carried by the shaft, aligns itself with the magnetic field generated by the stator of the motor.

Abstract: An electric motor and brake arrangement comprises an electric motor with a drive shaft for the motor and an output shaft for the arrangement, the output shaft carrying a radial supporting plate in which is provided a brake element with a brake shoe, the brake shoe being urged into contact with a brake drum associated with the casing by spring means and torque transmitting means on the drive shaft for transmitting torque to the brake element to release the brake, the brake element cooperating with stop means on the support plate for transmission of torque from the brake element thereto.

Abstract: A device is disclosed for braking the rod of an electric motor driven valve when the electric motor is put out of action and releasing the rod when the motor is brought into action. It includes a magnetic core integral with the stator of the motor and a magnetic armature capable of being attracted by the core to release the rod when the motor is supplied with current. Spring means automatically returns the device to its rod braking position when the supply of current to the motor is cut off.