Abstract: A hand brake system (40) for a rail vehicle providing a hand brake position alarm (76) before a train is moved with a hand brake not fully released. A switch (56) detects the position of a hand brake drive chain (18) to provide a brake engaged signal (60). The weight of the drive chain is supported through a load path that bypasses the switch. A master controller reverser handle position detector (74) provides a reverser handle position signal (72) when the reverser handle is moved out of neutral in preparation for providing power to the locomotive drive motors (15). A relay (70) is used to actuate the multiunit wheel slip indicator (54) and the general alarm bell (52) in every locomotive of the train consist when the brake engaged signal is coincident with the master controller reverser handle position signal. This combination of alarms, which normally indicates a locked axle when the train is above a predetermined speed, is interpreted as a hand brake position alarm when the train is at rest.

Abstract: An electromechanical wheel brake device has a helical gear for converting the rotating motion of an electric motor into a translating motion of a brake piston in order to press a brake pad against a brake disc in an advancing stroke or in order to release the brake pad in a restoring stroke. In addition, a clutch is provided, which operatively disengages a part of the helical gear from the electric motor should a permissible restoring stroke be exceeded. This prevents a mechanical failure or damage to the wheel brake device in the event of such a malfunction. The electromechanical wheel brake device can be used in motor vehicles such as cars.

Abstract: An electric parking brake mechanism characterized in an electric parking brake for pressing a friction member to a braked member via a force transmission converting mechanism for converting a rotational movement of an electric motor to a linear movement, including an input shaft connected to a side of the electric motor, an output shaft connected to a side of a brake mechanism for pressing the friction member to the brake member and a cam mechanism interposed between the input shaft and the output shaft, the cam mechanism is provided with a plurality of cam members and each having a cam face having a radius gradually increasing relative to a rotational center and in driving only a side of the output shaft, rotation of the output shaft is hampered by operating all of the plurality of cam members to constitute sides of large diameters.

Abstract: The present invention relates to a method for establishing the relationship between actuator position and actuator clamping force as well as a control system for applying defined actuator clamping forces to a brake operated electrically using an actuator. The method according to the present invention makes it possible to determine the initially unknown relationship between actuator position and actuator clamping force in real time without using any force sensor at all.

Abstract: The invention relates to a method for actuating a wheel brake assembly, in particular an electromechanical wheel brake assembly (10) or a mechanical system involving friction and having spring elasticity. To increase a braking force once a quasi-static terminal state of the wheel brake assembly (10) is reached, the invention proposes actuating the wheel brake assembly (10) for a brief period of time in the release direction and then to re-tighten it; the period of time of the actuation in the release direction is selected to be so brief that the braking force is reduced, if at all, only imperceptibly.

Abstract: The invention relates to an electromechanical disk brake (10). To attain brake boosting, the invention proposes embodying the disk brake (10) with a multiple brake cylinder (24), which is displaceable in a secant direction of a brake disk (20), and which has both a friction brake lining piston (22), which is displaceable transversely to the brake disk (20), and two brake booster pistons (26), disposed facing one another, which are displaceable parallel to the brake disk (20), and which are braced on fixed abutments (36), for instance on an inside of a brake caliper (12) of the disk brake (10). For actuation of the disk brake (10), the multiple brake cylinder (24) is displaced in the direction of rotation (46) of the brake disk (20), and as a result, the brake booster piston (26) that is at the front in the displacement direction moves into the brake cylinder (26) and, via the friction brake lining piston (22), presses the friction brake lining (18) against the brake disk (20).

Abstract: An electric braking apparatus is disclosed in which a rotational movement from a motor is converted into linear movement that moves a brake piston to generate braking force. The electric brake apparatus can perform full parking brake function without sacrificing its original braking function. In operation, immediately after generation of braking force caused by rotation of the rotor (26) supply of electricity to the motor is turned off. After supply of electricity is turned off, however, the rotor (26) is restricted from returning to its original position due to an engagement with an engaging claw (54) via a claw wheel (50), thereby keeping the barking brake remain effective. When electricity is thereafter supplied to the motor, the rotor (26) generates rotational torque sufficiently strong to push down the engaging claw (54) for disengagement, thereby releasing the parking brake.

Abstract: An electrically or manually operable brake drive for the brakes of a vehicle which has a gear train optionally driven by a reversible electric motor or a manual member. The brakes can be set or released by the electric motor without manual changing of the drive components permitting setting and releasing of the brakes at a location remote from the drive. For maintaining the brakes in a “set” mode, the drive includes a gradual release detent mechanism which permits rotation of the gears in the brake setting direction but opposes such rotation in the opposite direction unless a drive shaft rotatable by the motor or the manual member is rotated in the brake release direction.

Abstract: An actuator including a housing accommodating a screw mechanism and a drive including a motor. The screw mechanism includes a nut and a screw, one of which is rotatably supported with respect to the housing. Upon relative rotation of the nut and the screw, linear movement of one of the nut and the screw is obtained. At least a rotatable component of the drive, for example, the rotor of the motor, is rotatably supported on the screw which is rotatably supported with respect to the housing.

Abstract: An electric parking brake system that includes a parking brake, and an electric motor, wherein the parking brake is activated by the electric motor. Operation of the parking brake is controlled such that a vehicle is decelerated at a target deceleration of a predetermined magnitude when an operation command to operate the parking brake is issued by a driver via an operation switch while the vehicle is running. If a service brake fails while a vehicle is running, when the driver depresses the operation switch to issue the operation command to a parking brake to brake the vehicle, the parking brake is controlled such that the vehicle is decelerated at the target deceleration of the predetermined magnitude set on the basis of the number of times of depressing the operation switch.

Abstract: A method of accommodating wear in an electrically operated brake assembly includes setting a home position when a brake shoe engages a brake drum. A stepper motor drives the brake shoes into engagement with the drum. Upon engagement of the brake shoes with the drum, the stepper motor slips. Slipping of a stepper motor indicates that a home position has been reached. Upon release of the brake, the brake shoe is moved away from the drum a fixed distance. The fixed distance is an optimal distance between the friction member and the rotating member such that regardless of wear, the distance relationship between the brake shoe and drum is maintained.

Abstract: A disc brake assembly has a hub that is rotatable about an axis and at least a pair of discs supported on the hub for relative axial movement along the axis of the hub with the discs having opposite sides presenting braking surfaces. A non-rotatable support structure supports a plurality of friction elements for relative axial movement into and out of frictional braking engagement with the braking surfaces of the discs. An electric actuator is mounted on the support structure adjacent at least one of the friction elements and is operative when actuated to move the friction elements into frictional braking engagement with the braking surfaces of the discs.

Abstract: An actuating unit for an electromechanically operable disc brake for automotive vehicles including a driving unit or an electric motor, an actuating element secured against rotation and causing one of two friction linings that are arranged slidably in a brake caliper to move into engagement with a brake disc, as well as a reducing gear interposed between the electric motor and the actuating element. To ensure the testability of the reducing gear, the present invention includes an anti-rotation mechanism of the actuating element be arranged in a gearbox casing accommodating the reducing gear.

Abstract: A vehicle brake control system includes an improved ACC system for controlling the operation of a brake actuator and a throttle actuator, based on a signal from a preceding vehicle detector such as a radar device, so that a subject vehicle tracks a preceding vehicle. After a regular brake device is actuated to stop the subject vehicle, an EPB ECU disengages the regular braking device and, instead, actuates an electrically initiated and mechanically maintained parking brake device, so as to temporarily maintain the subject vehicle in a stationary state. Once the electric parking brake device is initiated, its braking state is mechanically maintained even if the flow of current is cut off. Therefore, neither the regular brake device nor the electric parking device consume power while the vehicle is in a stationary state, thereby saving power and minimizing electrical heat generation.

Abstract: An electrically operated disc brake includes a ball/ramp mechanism operable to convert rotary motion of an electric motor to linear motion and transmit the linear motion to a piston so that the piston is advanced to urge a pair of friction pads against opposite sides of a disc rotor to produce a barking force. The disc brake also includes a pad wear adjusting mechanism operable to threadably move the piston relative to an axially movable member of the ball/ramp mechanism in response to the amount of pad wear. The axially movable member has a female thread along its full length. The piston includes a piston head and a piston rod joined to the piston head. The piston rod has a male thread or threaded section. The threaded section has a length such that the piston can safely be moved together and relative to the axially movable member. The piston also has a smooth section extending from the threaded section toward the disc rotor.

Abstract: A parking brake is disclosed, comprising a brake-actuating electric motor (1), a brake actuating output shaft (2) driven by said electric motor and extending along a second axis (A2), a brake-actuating linkage (4) that is adjustably arranged parallel to a first axis (A1) that substantially extends perpendicularly to the second axis (A2), and a drive connection from the brake-actuating output shaft (2) to the brake-actuating linkage (4). The drive connection is configured in the form of a cam-type cam disk or gate guide (3) that translates the rotation of the brake-actuating output shaft (2) into a translational movement of the brake-actuating linkage (4) through an adjusting element (5) that is guided along a surface (F) of the cam disk or gate guide 93) forming a radial profile. The motor axis (A3) of the brake-actuating electric motor (1) extends substantially perpendicular to the second axis (A2).

Abstract: A vehicular brake apparatus, which is provided at a shaft of a motor that revolves due to depression of a brake pedal, has a variable gear mechanism including a non-circular spur gear that changes a reduction ratio from a high gear ratio to a low gear ratio along with revolution. Revolution is converted to linear movement by roller bearings interposed between two ramp portions each having a straight inclined surface, and a friction member is pressed against a disk by a friction material holding portion being moved in a straight direction. Further, a braking force is generated on the disk by the friction member and another friction member provided on the opposite side of the caliper.

Abstract: A screw actuator which has a housing, a motor, an actuating member and a screw mechanism which provides a linear movement of the actuating member with respect to the housing in response to a rotational movement of the motor. The screw mechanism has a screw and a nut engaging each other by rolling elements, one of the screw or the nut is rotatbly supported with respect to the housing, and a reduction gear means. The nut is fixed with repect to the housing, and the screw is rotatably supported with respect to the housing by mean of rolling elements.

Abstract: The invention relates to an electromechanical wheel brake device, with an electric motor that can press a frictional brake lining against a brake body (brake disk) by a reduction gear (planetary gear) and a rotation/translation conversion gear (ball screw). The invention proposes embodying the electric motor as a transverse flux motor with three phase windings; each phrase winding has a circular, annular excitation winding that is disposed inside U-shaped yokes, which are distributed over the circumference of the excitation winding. This embodiment of the electric motor permits a compact design of the electric motor in an annular, hollow shaft design so that the reduction gear and the rotation/translation conversion gear can be disposed at least partially inside the electric motor.

Abstract: A slidable disc brake assembly for vehicles includes a rotatable hub, at least one friction disc rotatable but slidable along the hub, at least two friction pads on axially opposite sides of the disc with at least one being slidable on a brake caliper. The caliper is provided with an electric primary actuator which is operative to slide the brake disc and the friction pad or pads into frictional engagement with one another.

Abstract: A manually operated cable release apparatus, suitable for use in an electrically actuated brake, is provided for a locking mechanism having a shaft that is rotatable about an axis of rotation of the shaft, between a first angular position where the locking mechanism is disengaged, and a second angular position where the locking mechanism is engaged. The cable release apparatus includes a lever having one end thereof fixedly attached to the shaft and extending outward from the shaft for applying a force to the lever, for rotating the shaft back and forth through an angular displacement between the first and second angular positions.

Abstract: An electrically actuated parking brake system and actuator therefor. The actuator includes a motor having a drive shaft, and a gear train coupled to the drive shaft, wherein the gear train provides at least one mechanical output from the actuator. The gear train may include a drive gear coupled to the drive shaft, a driven gear coupled to the drive gear, and a planetary gear set coupled to the driven gear. Various configurations are provided for isolating actuator components for controlling audible noise, including sub-frame isolation configurations, motor isolation configurations, and gear train isolation configurations.

Abstract: An electrical vehicle parking brake device capable of reducing the size towards a cable shaft and improving the degree of freedom of mounting in a vehicle is provided for the electrical vehicle parking brake device of controlling the braking force to a wheel due to the driving power of a motor which is transmitted by way of a cable at the time of parking the vehicle.

Abstract: An electric brake actuator (14), including a rotatable member (21) and electric drive means (34) for driving the rotatable member (21) to rotate. The rotatable member (21) is arranged for engagement with a continuous cable (18) that in use extends between and in connection with a pair of brake assemblies (12) that are operable when actuated to apply a braking load to brake a wheel associated with each respective brake assembly. The rotatable member (21) is arranged such that it is operable to pull the cable (18) on each side of the rotatable member (21) upon rotation of the rotatable member (21) in a first direction, for actuation of the brake assemblies (12), and to extend the cable (18) on each side of the rotatable member (21) upon rotation of the rotatable member (21) in a second and reverse direction.

Abstract: An electric mechanical brake assembly including an electric-mechanical-brake ballscrew subassembly, a first electric motor, and a first worm or cluster gear set. The electric-mechanical-brake ballscrew subassembly has a rotatable actuation member and has a linearly-movable member which is driven by the actuation member and which is attachable to a brake pad. The first electric motor has a first drive shaft. The first worm or cluster gear set at least in part operatively connects the first drive shaft to the actuation member.

Abstract: A parking brake actuation assembly is provided including an electric motor and a first rotatable member operatively connected to the electric motor so as to enable the motor to rotate the first rotatable member in a brake applying rotational direction. The first rotatable member normally is prevented against rotation in a brake releasing rotational direction. A second rotatable member is rotatable relative to the first rotatable member and includes cable attachment structure for affixing a brake activation linkage thereto. A clutch spring is disposed between the first and second rotatable members and is configured to contract upon initiation of rotation of the first rotatable member in the brake applying direction so as to couple the second rotatable member to the first rotatable member for affecting rotation of the second rotatable member in the brake applying direction.

Abstract: An electromechanical brake assembly 10 having a pair of selectively movable and dissimilar self energization wedge members 24, 26 which are respectively and independently controlled by motors 30, 34, and which have respectively dissimilar angles of inclination 60, 62, thereby providing a controllably varying amount of self energization.

Abstract: An actuating unit for an electromechanically actuated disc brake for automotive vehicles which is composed of a drive unit or an electric motor, an actuating element forming one of two friction linings into engagement with a brake disc, and a reducing gear. A freewheel mechanism that interacts with the electric motor has the function of a parking brake. In order to ensure a high level of reliability in operation of the parking brake and to render it resistant to external influences, in particular, oscillations or vibrations, the present invention suggest that the freewheel mechanism be configured in such a way that its clamping effect is produced by a form-locking torque transmission and that, in its actuated state, it prevents a rotational movement of a bearing in which the rotor of the electric motor is mounted.

Abstract: A screw actuator (4) comprises a housing (1), a nut (5) and a screw (6) one of which is axially fixed with respect to the housing and the other of which is axially displaceable with respect to the housing for moving an head (21), as well as a motor (7) which comprises a stator (8) connected to the housing, and a rotor (9) which is drivingly connected to a rotatable part (6) of the screw actuator, the housing having a bore (10) accommodating at least the nut and/or screw, an axially fixed part of said nut or screw being supported with respect to a radial support abutment (11) which extends inwardly in the bore. The rotor of the motor is supported rotatably on a sleeve (13), said sleeve engaging the fixed part and extending away from the brake pad, said sleeve having a radially outwardly extending sleeve flange (14) which is interposed between said support abutment, and the axially fixed part.

Abstract: An electrically activated parking brake can include a constant power motor for actuating a cam that is connected via a cable to the parking brake. The cam has a variable radius perimeter such that a roller follower or linkage operably engages the cam by rolling along the perimeter of the cam. The follower will move radially outward from the center of rotation, as the cam rotates in a positive direction. A cable is operably attached to the follower and to a cable mechanism operably associated with a brake system on a wheel. The brake system applies the brakes when the cable or linkage is pulled by the follower after the cam rotates a full cycle.

Abstract: A brake actuation assembly for a vehicle is actuatable to apply and release tension to one or more elements that connect to a brake system of the vehicle. The brake actuation assembly includes an electrically powered brake actuator, a manually operable control, and a manual brake actuator. The electrically powered actuator includes a motor with a driveshaft for driving connection with the elements. The motor is actuatable to rotate the driveshaft in a brake-applying direction to apply tension to the elements and in a brake-releasing direction to release tension to the elements. The manual actuator includes a handle and a cable. The manual actuator is movable between an operative position wherein the cable connects the handle to the driveshaft to enable rotation of the handle to rotate the driveshaft in the brake-applying and brake-releasing directions via the cable, and an inoperative position wherein the handle is disconnected from the driveshaft.

Abstract: An actuator (5) comprises a housing (4) with a motor (6) and a screw mechanism (9), said screw mechanism comprising nut (10) and a screw (11) one of which is rotatably supported with respect to the housing by means of a screw mechanism support (13) allowing relative rotations of the screw and the nut with respect to the longitudinal screw mechanism axis (28), and an actuating member (15) connected to the screw mechanism by means of an actuating member connection (26), such that on relative rotation of the nut and screw the actuating member is displaced with respect to the housing. The screw mechanism support and the actuating member connection allow rotations having at least one axis transverse with respect to the longitudinal screw mechanism axis, so as to compensate traverse loading and bending moments.

Abstract: An actuation system controls the flow of electric power to electromagnetic actuators to control motion or movement of at least two shafts or bodies. The system is preferentially applied to braking systems in automobiles and trucks, and may also be applied to other areas, including clutches and drive systems for other power transmission purposes. The electromagnetic retarders may also be used in combination with friction brake systems. Principal advantages of the combination system are the reliability and simplicity of friction and hydraulic components, and the lower wear and longer life of electromagnetic components.

Abstract: An electrically actuated aircraft brake system and method which provides for brake wear measurement, brake running clearance adjustment, ram position-based control and improved construction and operation. Brake wear and running clearance measurement are obtained by analyzing the output of position sensing circuitry. The position sensing circuitry, preferably including a LVDT position sensor, is also used to determine braking load, a brake controller including circuitry for effecting displacement of one or more reciprocating rams to load a brake disk stack by a predetermined amount based on a present displacement value of the position signal obtained from the position sensor. The position sensor preferably includes a LVDT transducer connected between the reciprocating ram and a brake housing, and the motive device preferably includes a servo motor.

Abstract: An actuator for a drum brake comprises a housing (1), a screw mechanism having at least one screw (3,6) and a nut (4, 7), which screw mechanism (2) is supported with respect to the housing (1), and drive means (3) which are drivingly connected to the screw mechanism for providing a linear movement of at least one of the screw and nut with respect to the housing upon driving the screw mechanism. The screw mechanism comprises two axially aligned screws which have opposite lead angles and two corresponding nuts, said screws each engaging a respective nut, the drive means being connected to both screws or to both nuts.

Abstract: An electric brake actuator for actuating a brake arrangement. The actuator includes an electric drive unit (15, 15′) and a load multiplier (17). the electric drive unit (15, 15′) is in cable connection through a first cable unit (16, 16′) with the load multiplier and the load multiplier (17) is arranged for cable connection through a second cable unit (19) with the brake arrangement. Whereby the electric drive unit (15, 15′) is operable to apply a load to the load multiplier (17) through the first cable unit (16, 16′) and the load multiplier (17) is operable to multiply the load for application to the brake arrangement through the second cable unit (19).

Abstract: The invention relates to a brake application device for a motor vehicle brake, in particular to a brake application device for a rail vehicle brake and preferably to a brake application device for a rail vehicle disc brake, comprising a braking force generator for applying and/or releasing the vehicle brake and a braking force converter for converting the energy delivered by the braking force generator into a brake application motion. The brake application device is characterised in that the braking force converter is configured in such a way that the force which is to be exerted by the braking force generator during braking, in order to generate a defined brake application force which is greater than zero and less than the maximum brake force, measures zero.

Abstract: An electrically operated parking brake apparatus that includes a ball screw mechanism driven by an electric motor so as to move a nut member along a screw-threaded shaft. Two Bowden cables, for example, are connected to left and right ends of an equalizer supported on the nut member via an upper support shaft and a lower support shaft for transmitting brake operation force to wheel brakes. Since an axis of the upper and lower support shafts provided at positions facing each other across the screw-threaded shaft for swingably supporting the equalizer on the nut member passes through the center of the screw-threaded shaft, and a line connecting portion where the pair of Bowden cables are connected to the equalizer passes through the center of the screw-threaded shaft, the application of an unbalanced load to the screw-threaded shaft is prevented.

Abstract: An electrically operated parking brake apparatus that includes an electric motor and a screw mechanism The screw mechanism includes a screw-threaded shaft adapted to be rotationally driven by the electric motor, and a nut member meshing with the screw-threaded shaft, the nut member being movable along the screw-threaded shaft by the rotation of the screw-threaded shaft. The parking brake apparatus also includes a transmission member connected to the nut member for transmitting a brake operating force to a wheel brake, and a rotation preventing unit for preventing the rotation of the screw-threaded shaft so as to hold the brake operating force by fixing the position of the nut member relative to the screw-threaded shaft. The rotation preventing unit in one embodiment is an electromagnetic brake for confining the screw-threaded shaft to a stationary portion of a vehicle body.

Abstract: An automatically acting braking system for a stepper motor (10) of the type having a rotor (18) that is radially centered within a stationary stator (12) and which rotates about the central axis of a central shaft (30). The rotor (18) is allowed to axially slide back and forth, biased in one direction continually by a resilient means (40). When the stator (12) is energized, it pulls the rotor (18) to an axially centered position within stator (12), but when it is de energized, the resilient means (40) pushes the rotor (18) to one side, lockingly engaging its teeth (24) with the teeth (44) of a fixed locking ring (42).

Abstract: An electrically driven brake booster (1) includes an input member (4) disposed in operative association with a brake pedal (12), an output member (5) disposed in operative association with the master cylinder (6), and drive transmitting device (10) for translating a rotating motion of a motor (9) into a linear motion to be transmitted to the output member (5). The drive transmitting device (10) comprises a rack (23) formed on the output member (5), and pinions (21, 22) disposed in operative association with the motor (9) and in meshing engagement with the rack (23). Also, reaction transmitting device (8) which transmits a brake reaction to the input member (4) and the output member (5) at a given proportion is provided. In comparison to conventional drive transmitting device, the drive transmitting device (10) of the present invention has a simple construction, a reduced weight and a better transmission efficiency.

Abstract: A motor system includes an electric motor, a shaft extending through the motor and through a magnetorheological fluid stopper, which comprises a rotor and a stator in operable communication with the rotor. A magnetorheological fluid is disposed at the rotor and the stator.

Abstract: An actuator (7) comprises a housing (8) which contains a screw mechanism (9) and a motor (10) which is drivably connected to the screw mechanism (9), said screw mechanism (9) providing a linear movement in response to a rotational movement of the motor (10), and comprising a screw (12) and a nut (13) one of which is supported rotatably with respect to the housing (8) by means of a rolling element bearing (25, 62). Support means (22, 61) have been provided which extend axially with respect to the screw mechanism (9), said support means (22, 61) engaging the housing (8), and supporting the screw mechanism (9) so as to take up the axial loads exerted on said screw mechanism (9).

Abstract: A brake apparatus for a vehicle includes a housing including a bore formed therein. A piston is slidably positioned in the bore, the piston and bore defining a fluid chamber therebetween. A screw member is operatively engaged with the piston. The piston and screw member are movable based on fluid pressure in the fluid chamber and movable in a linear direction based on the rotational movement of the screw member.

Abstract: An electric brake actuator for actuating a brake arrangement. The actuator includes an electric drive unit (15, 15′) and a load multiplier (17). The electric drive unit (15, 15′) is in cable connection through a first cable means (16, 16′) with the load multiplier and the load multiplier (17) is arranged for cable connection through a second cable means (19) with the brake arrangement. Whereby the electric drive unit (15, 15′) is operable to apply a load to the load multiplier (17) through the first cable means (16, 16′) and the load multiplier (17) is operable to multiply the load for application to the brake arrangement through the second cable means (19).

Abstract: An electric braking apparatus is disclosed in which a rotational movement from a motor is converted into linear movement that moves a brake piston to generate braking force. The electric brake apparatus can perform full parking brake function without sacrificing its original braking function. In operation, immediately after generation of braking force caused by rotation of the rotor 26, supply of electricity to the motor is turned off. After supply of electricity is turned off, however, the rotor 26 is restricted from returning to its original position due to an engagement with an engaging claw 54 via a claw wheel 50, thereby keeping the barking brake remain effective. When electricity is thereafter supplied to the motor, the rotor 26 generates rotational torque sufficiently strong to push down the engaging claw 54 for disengagement, thereby releasing the parking brake.

Abstract: An electromechanical wheel brake device for a motor vehicle, having an electric motor for driving two planetary gears, connected in series with one another, which actuate the wheel brake device via a threaded roller gear. The planetary gear is provided with a first electromagnetic coupling, with which a sun wheel of the second planetary gear can be locked, or can be connected in a manner fixed against relative rotation to a sun wheel of the first planetary gear, and with a second electromagnetic coupling, with which a ring gear of the second planetary gear can be stopped or can be connected in a manner fixed against relative rotation to a ring gear of the first planetary gear. By means of the electric motor, by switching of the two couplings, the rolling thread drive can be driven fast to overcome an air gap, slowly and with major speed reduction for the ensuing exertion of a high braking force, and fast for releasing without a reversal of the direction of rotation of the electric motor.

Abstract: A park brake system for vehicles is provided that has an actuator with an electric drive motor and an electronic control unit provided with an interface. A reduction gear has an input connected to the output of the electric motor and an output member for connection to mechanical brakes of the vehicle. A command unit has a transducer connected to the electronic control unit. The transducer converts position indication signals into appropriate digital signals to enable the control unit to generate corresponding brake control commands. With appropriate control signals from the electronic control unit, the mechanical brake system can thus reflect positional brake commands from the command unit within an operating range from OFF to ON, including partial activation conditions of the park brake.

Abstract: A vehicle braking system having an operating member (103) by way of which a foundation braking force can be transmitted to a brake actuator in accordance with a driver's intentions, wherein there is provided a park brake mechanism (24) which provides the facility of electric motor driven actuation of the operating member (103) of the brake for the parking phase of braking.

Abstract: An actuator comprising, a first, rotatable member arranged to be driven by a motor, a sleeve, said first member cooperating with said sleeve such that rotation of the first member at a given speed relative to said sleeve causes the sleeve to be translated axially at a first speed through a predetermined distance, stop means limiting axial translation of the sleeve reative to the first member whereafter during continued rotation of the first member the sleeve rotates with the first member, a second, non-rotatable, member, said sleeve cooperating with said second member whereby rotation of the sleeve at said given speed causes axial translation of the second member relative to said sleeve at a second speed and, a brake arrangement applying a braking force to the sleeve, the braking force resisting rotation of the sleeve but not significantly affecting translation of the sleeve.