Vehicle brake and method for actuating a vehicle brake

In a vehicle brake comprising a housing, a brake piston, which is accommodated in the housing and on which a brake lining is fitted, and a blocking device, it is provided that the brake piston is displaceable in the housing by means of an actuating device and that the brake piston is securable relative to the housing by means of the blocking device. In this vehicle brake, it is further provided that the blocking device comprises an electromechanical latching arrangement, which is actuable in such a way that in a latching position it prevents a displacement of the brake piston inside the housing and in a release position it enables a movement of the brake piston in the housing.

BACKGROUND OF THE INVENTION

The invention relates to a vehicle brake comprising a housing, a brake piston, which is accommodated in the housing and on which a brake lining is fitted, and a blocking device, wherein the brake piston is displaceable in the housing by means of an actuating device and wherein the brake piston is securable relative to the housing by means of the blocking device.

Such a vehicle brake is known for example from the European patent EP 0 551 397, and corresponding U.S. Pat. No. 5,148,894 A1, both of which are incorporated by reference herein in entirety. With this vehicle brake, in a service braking situation, i.e. when a brake disc coupled to a vehicle wheel is to be braked to decelerate the vehicle wheel, a brake piston is displaced relative to the housing and pressed against the brake disc by feeding hydraulic fluid into the fluid chamber. The brake force then exerted on the brake disc is dependent upon the magnitude of the hydraulic pressure prevailing in the fluid chamber. At the end of the service braking situation, hydraulic fluid is discharged from the fluid chamber, thereby allowing the brake piston with its brake lining to move away from and release the brake disc. In a parking braking situation, in which a vehicle equipped with such a brake is to be prevented from unintentionally rolling away by firmly clamping the stationary brake disc against unintentional rotation, in this vehicle brake first the brake piston is again fed towards and pressed against the brake disc by feeding hydraulic fluid into the fluid chamber. Then a motor-driven blocking rod is displaced inside the housing and brought into contact with the brake piston. The blocking rod is supported by a self-locking thread pairing in the housing. The effect achievable thereby is that the blocking rod under the action of axial forces is blocked in its axial position. This effect is utilized to block the brake piston in its brake application position. After the brake piston has been contacted by the blocking rod, hydraulic fluid may be discharged from the fluid chamber, wherein the blocking rod holds the brake piston in its braking position. The hydraulic fluid circuit is therefore relieved and the parking braking function of the vehicle brake is activated. To cancel the parking braking function, the fluid chamber is filled anew with hydraulic fluid until the hydraulic pressure prevailing therein is high enough for the brake piston to release the blocking rod. The blocking rod may then be displaced mechanically into its basic position. The hydraulic fluid is subsequently discharged from the fluid chamber, with the result that the brake piston may readopt its braking-effect-free basic position. For displacement of the actuating rod, according to this patent an electromotive drive is required, thereby lending the entire arrangement a relatively complicated construction. The required electric motor is moreover an additional load on the electrical system of a motor vehicle.

BRIEF SUMMARY OF THE INVENTION

The problem of the present invention is to provide a vehicle brake of the initially described type that combines a simple and compact construction with fast and reliable activation of the parking braking function.

In a vehicle brake of the initially described type, this problem is solved in that the blocking device comprises an electromechanical latching arrangement, which is actuable in such a way that in a latching position it prevents a displacement of the brake piston inside the housing and in a release position it enables the brake piston to move in the housing.

Thus, the conventional measures for activating a service braking function, during which the brake piston is displaced inside the housing, may be used also to activate the service braking function. Once the brake piston has been fed towards and pressed against a brake disc of the vehicle brake in such a manner, the latching arrangement may then be activated, by means of which the brake piston is blocked in the housing and secured in its currently fed position.

With regard to the mechanical construction of the latching arrangement, it may be provided that it comprises a detent element arrangement having at least one detent element, which is displaceable between a detent element position associated with the locking position and a detent element position associated with the release position and which is latchable through self-locking engagement with a detent-element working surface of a counterpart detent component drive-connected to the brake piston. In order to bring about a defined position in the unloaded state, in a development of the invention the at least one detent element may be biased into its detent element position associated with the release position by means of a spring element. For actuating the latching arrangement, the at least one detent element may be displaceable between its detent element position associated with the latching position and its detent element position associated with the release position by means of an electromechanical actuator.

An advantageous development of the invention provides that two detent elements are actuable by means of the electromechanical actuator, wherein the distance between the detent elements and the pitch of the counterpart detent component designed with a plurality of detent-element working surfaces are tuned in such a way to one another that in the locking position only one of the detent elements is in self-locking engagement with one of the detent-element working surfaces and the, in each case, other detent element in said case engages without self-locking between two adjacent detent-element working surfaces. In this way, it is possible to achieve a doubling of the detent stages, i.e. a refinement of the distances between individual detent positions.

In a form of construction of the invention, it may be provided that the at least one detent element is formed by a pawl and that the detent-element working surfaces of the counterpart detent component take the form of detent teeth. Alternatively, the at least one detent element may be formed by a detent pin and the detent-element working surfaces of the counterpart detent component may take the form of detent-pin recesses.

For the drive connection of brake piston and counterpart detent component, a constructional variant of the invention provides that the brake piston is connected by a self-unlocking thread pairing to a blocking element of the blocking device. In said case, the self-unlocking thread pairing may be formed by an external thread, which is provided on a threaded bolt fastened to the brake piston, and an internal thread, which is provided on a locating bush fastened to the blocking element. Alternatively, in a further constructional variant of the invention, it may be provided that the self-unlocking thread pairing is formed by an internal thread, which is provided on the brake piston, and an external thread, which is provided on the blocking element.

For reducing the forces arising at the latching arrangement, a development of the invention provides that the blocking element is drive-connected to the counterpart detent component by a gear device, in particular by a planetary gear. In said case, it may be provided that the blocking element is connected in a rotationally fixed manner to a sun wheel of the planetary gear, that moreover the counterpart detent component is connected in a rotationally fixed manner to a planet carrier of the planetary gear and that the ring gear of the planetary gear is formed in or connected in a rotationally fixed manner to the housing. Alternatively, it may be provided that the blocking element is connected in a rotationally fixed manner to a planet carrier of the planetary gear, that moreover the counterpart detent component is connected in a rotationally fixed manner to a sun wheel of the planetary gear and that the ring gear of the planetary gear is formed in or connected in a rotationally fixed manner to the housing. For further reducing the forces arising at the latching arrangement, it may be provided that the planetary gear is of a multi-step design.

The actuating device may be of a hydraulic design, wherein the brake piston with the housing delimits a fluid chamber, which via a hydraulic fluid circuit is chargeable with hydraulic fluid, so that for actuation of the vehicle brake the brake piston is hydraulically displaceable inside the housing along a piston longitudinal axis. Equally, in a form of construction according to the invention, it is possible for the actuating device to be an electro-mechanical design, wherein for actuation of the vehicle brake the brake piston is displaceable inside the housing along a piston longitudinal axis through activation of an electric motor.

For supporting the blocking element rotatably in the housing, a radial bearing arrangement or/and thrust bearing arrangement may be provided.

For operation of the vehicle brake according to the invention, it may be provided that in a service braking situation the brake piston is displaceable inside the housing by activating the actuating device and that in a parking braking situation first the brake piston is displaced inside the housing by activating the actuating device, then the blocking device is actuated and the brake piston is blocked inside the housing and finally the actuating device is deactivated. For cancelling the parking braking situation, the actuating device may then be reactivated until the blocking element releases the brake piston and finally the brake piston is returned to its braking-effect-free basic position.

The invention further relates to a method of actuating a vehicle brake of the previously described type, whereby in a service braking situation the brake piston is displaceable inside the housing by activating the actuating device and in a parking braking situation first the brake piston is displaced inside the housing by activating the actuating device, then the blocking device is actuated and the brake piston is blocked inside the housing and finally the actuating device is deactivated. In this method according to the invention, it may further be provided that for cancelling the parking braking situation the actuating device is activated until the blocking element releases the brake piston and finally the brake piston is returned to its braking-effect-free basic position.

Other advantages of the invention will become apparent to those skilled in the art from the following detailed description of the invention, when read in light of the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION

InFIG. 1a first embodiment of a vehicle brake according to the invention is shown in longitudinal section and generally denoted by10. The vehicle brake10, as will be additionally explained below in detail, is actuated electromechanically. It takes the form of a disc brake of the floating caliper type. For this purpose, the vehicle brake10comprises a housing12with a floating caliper region14. In the floating caliper region14a first brake lining16and a second brake lining18are disposed. The two brake linings16and18are resiliently connected to one another by a release play spring20, wherein the release play spring20attempts to push the two brake linings16and18apart from one another. Accommodated between the two brake linings16and18is a brake disc (not shown), which is connected at its radially inner region to a vehicle wheel (likewise not shown) that is to be braked. The brake lining18is fitted on the floating caliper region14of the housing12so as to be displaceable in the direction of the longitudinal axis A. The brake lining16is supported opposite so as to be displaceable in the direction of the longitudinal axis A.

The displacement of the brake lining16in the direction of the longitudinal axis A is effected by means of an electrically actuable actuator24. The electrically actuable actuator24comprises an electric motor26and a self-unlocking spindle/nut gear arrangement28. The electric motor26takes the form of an internal-rotor motor. It comprises a stator30, which is accommodated in a housing lid32fastened to the housing12. Situated radially inside the stator30is a rotor34, which on its radially outer peripheral surface has permanent magnets36, by means of which it is mechanically driven in the magnetic field built up upon energization of the stator. The rotor34is supported via a bearing arrangement38on an axial extension40of a bearing bush58fixed in the housing12and hence rotatably relative to the housing12about the axis A. In its radially inner region, the rotor34is connected in a rotationally fixed manner to an externally geared bolt42. This bolt42extends in axial direction centrally in the direction of a planet carrier44of a planetary gear46.

The planet carrier44holds planet wheels50by means of bearing pins48, wherein the axes of rotation of the bearing pins48extend parallel to the longitudinal axis A. The planet wheels50at their, in relation to the longitudinal axis A, radially inner region are in mesh with the externally geared bolt42. In their, in relation to the longitudinal axis A, radially outer region the planet wheels50are in mesh with ring gear teeth52, which are formed on the axial extension of the bearing bush58. The bearing bush58on its end remote from the internal gearing52has a flanged portion60, by which it is supported in axial direction against the housing.

The planet carrier44on its, inFIG. 1, right side has a bolt-shaped axial extension54, which is provided with external gearing. In mesh with this external gearing are further planet wheels56, which further mesh with the ring gear teeth52of the bearing bush58. The planet wheels56are supported by means of bearing pins59rotatably against the rear of a spindle64.

The spindle64on its outer peripheral surface has a guideway66, which extends spirally around the axis A and in which spherical bearing bodies68are guided. The spindle64is embraced by a nut70, which likewise has on its inside at least in sections a correspondingly spiral guideway, into which the bearing bodies68likewise engage. The spindle64, the bearing bodies68and the nut70form the self-unlocking spindle/nut gear arrangement28.

The spindle64is supported via a plain bearing arrangement72in the bearing bush58. The bearing bush58moreover guides the nut70in the direction of the axis A and prevents misalignment of the nut70. On the flanged portion60of the bearing bush58flexible bellows74are provided, which interact in a sealing manner with a cover76fitted on the nut70.

The rotor34at its, inFIG. 1, left region is provided with spur gearing78. By means of an electrically controllable lifting magnet80a locking element82may be brought into engagement with the spur gearing78, with the result that the rotor34is locked against rotation about the longitudinal axis A. The locking element82and the lifting magnet80are biased into a release position, in which they allow a rotation of the rotor34. By energizing the lifting magnet80, the lifting magnet80shifts the locking element82into a latching position, in which the locking element82blocks the rotor34. The engagement of the locking element82into the spur gearing78is self-locking, i.e. it is unlockable only under the action of an axial force.

The vehicle brake10according toFIG. 1in a service braking situation, in which a rotating brake disc is to be braked, operates as follows. Upon energization of the electric motor26, the rotor34rotates about the axis A with low friction, owing to the bearing arrangement38. The rotation of the rotor34causes first the bolt42and, with it, the planet wheels50to be driven. These roll in the internal gearing52of the bearing bush58serving as a fixed ring gear, with the result that the planet carrier44rotates about the axis A, but at a different rotational speed from the rotational speed of the rotor34. The rotation of the planet carrier44is transmitted via the axial extension54and the planet wheels56, which likewise roll in the internal gearing52of the bearing bush58serving as a fixed ring gear, to the spindle64. The spindle64rotates with low friction inside the bearing bush58. Owing to the rotation of the spindle64, the nut70guided linearly in the bearing bush58is displaced in the direction of the longitudinal axis A. This means that the nut70is displaced axially in the direction of the longitudinal axis A because of the two guideways of the spindle64and the nut70by the agency of the bearing bodies68and therefore presses via the cover76upon the brake lining16. The brake linings16and18as a result of this pressure act in a floating manner upon the brake disc22and are applied against both sides thereof, with the result that the brake disc22is braked because of the frictional effect thus generated. When this braking effect is to be reduced or cancelled, the electric motor26is no longer energized or is even energized with reverse polarity. This leads to a reversible movement of the nut70along the spindle64.

In the case of a parking braking situation, in which a stationary brake disc is to be locked against unintended rotation, the brake linings16and18are first pressed against the non-illustrated brake disc. This is effected by energizing the electric motor26, in the manner described above for the service braking situation. Once a sufficiently high clamping force has been reached at the brake disc, the lifting magnet80is then activated. The lifting magnet80pushes the locking element82into its latching position, with the result that the rotor34is locked against rotation. This prevents a resetting motion of the brake piston14and hence of the brake linings16and18. The vehicle brake10remains in its applied position without any need for further energization of the electric motor26. By virtue of the action of the two-step planetary gear46, the peripheral force acting upon the locking element may be kept low. To cancel the parking braking situation, the lifting magnet80is activated so that it pulls the locking element82out of its latching position. The vehicle brake may then move back into its basic position shown inFIG. 1.

InFIG. 2a second embodiment of a vehicle brake according to the invention is denoted by110. The vehicle brake110comprises a housing112, in which a brake piston114is guided displaceably in the direction of a piston longitudinal axis A. The brake piston114with the housing112encloses a fluid chamber116, to and/or from which hydraulic fluid is feedable and/or dischargeable through a non-illustrated hydraulic fluid line of a hydraulic fluid circuit. The brake piston114guided in the housing112is connected at its, inFIG. 2, right front end by bellows122to the housing112, so that the housing interior is screened off to prevent dirt from penetrating. Disposed on the front end124of the brake piston114is a brake lining126, which is displaceable in the housing112. Disposed opposite the brake lining126is a second brake lining128, which is likewise displaceable in the housing112. The brake linings126and128are supported in the housing112in accordance with a conventional floating caliper arrangement so that, when the brake lining126is displaced by means of the brake piston114, the brake lining128is displaced equally, but in the opposite direction. Thus, a non-illustrated rotating brake disc disposed between the brake linings126and128may be clamped in between the brake linings126and128and therefore braked.

Disposed on the brake piston114in its radially inner region is a threaded bolt130. The threaded bolt130is accommodated by its external thread in a threaded location bore132of a shank portion of a blocking element134. The internal thread of the threaded location bore132in the blocking element134together with the external thread of the threaded bolt130forms a self-unlocking thread pairing.

The blocking element134further has a flange136, which extends radially outwards. By means of the flange136, the blocking element134is supported via a thrust bearing138in axial direction inFIG. 2to the left against a shoulder140of the housing112. At the side of the flange136remote from the thrust bearing138, a cup-shaped spring plate144is fitted in the housing112by means of a locking ring142fixed in the housing112. Disposed between the spring plate144and the flange136is a further thrust bearing146, which lies radially within the region, by which the spring plate144is supported via the locking ring142against the housing112.

On its side remote from the brake piston114, the blocking element134is connected to a planetary gear148, which is of a similar design to the planetary gear46ofFIG. 1. The planetary gear148comprises planet wheels150, which are supported rotatably against the blocking element134and which engage, in relation to the longitudinal axis A, radially at the outside into housing-fixed ring gear teeth152and mesh, in relation to the longitudinal axis A, radially at the inside with a sun wheel154. The sun wheel154is formed in a rotationally fixed manner on a planet carrier156. Supported rotatably on the planet carrier156are further planet wheels158, which engage, in relation to the longitudinal axis A, radially at the outside into the housing-fixed ring gear teeth152and mesh, in relation to the longitudinal axis A, radially at the inside with a sun wheel160. The sun wheel160is formed in a rotationally fixed manner on a detent disk162, which is supported via a bearing pin164rotatably in the housing112. The detent disk on its radial peripheral surface has detent teeth164. In the housing112an electrically controllable lifting magnet166is provided, which has a detent pin168. The detent pin168may be brought counter to a spring bias into self-locking engagement with the detent teeth164.

There now follows a detailed description of the operation of the vehicle brake110according to the invention ofFIG. 2.

In a service braking situation, in which a non-illustrated rotating brake disc disposed between the brake linings126and128is to be braked, the fluid chamber116is charged through the hydraulic fluid line with hydraulic fluid from the hydraulic fluid circuit, with the result that the brake piston114is displaced inFIG. 2along the piston longitudinal axis A. In said case, the brake linings126and128are pressed from both sides onto the non-illustrated brake disc, which is accordingly braked. To cancel the braking effect, hydraulic fluid is discharged from the fluid chamber116through the fluid line.

For the description of a parking braking situation, in which the non-illustrated brake disc disposed between the brake linings126and128is stationary and is to be locked against unintended rotation, reference is additionally made toFIG. 10.

In the parking braking situation, at time t0the fluid chamber116is charged through the fluid line with hydraulic fluid from the hydraulic fluid circuit. The brake piston114is therefore moved inFIG. 2to the right and displaces the brake linings126and128in a conventional manner towards one another, such that they press upon the brake disc. The hydraulic pressure in the fluid chamber116is increased from the value p0(0 bar) to the value p1(for example 160 bar). The brake piston114is therefore pressed inFIG. 2to the right to such an extent that a clamping force F1is generated at the brake disc. The hydraulic pressure in the fluid chamber116is then maintained at the value p1.

At time t2the lifting magnet166is activated, with the result that the detent pin168is brought into engagement with the detent teeth164. Rotation of the detent disk162and hence of the entire planetary gear148is therefore blocked. This means that a displacement of the brake piston114in the housing112is also blocked. Then, at time t3hydraulic fluid is discharged from the fluid chamber116, with the result that the pressure prevailing in the fluid chamber116drops from the value p1to the value p0, which is reached at time t5. Owing to the reduction of the hydraulic pressure prevailing in the fluid chamber116, the brake piston114moves slightly inFIG. 2to the left in the direction of its basic position. In said case, the clamping force acting upon the brake disc is reduced, i.e. it drops from the value F1to the value F2. This may be explained by the occurrence of mechanical setting operations. This may in particular be explained by the fact that because of the slight axial movement of the brake piston114inFIG. 2to the left the blocking element134, driven by the thread pairing of the threaded bolt130and the blocking element134, may rotate slightly until the detent teeth164move into self-locking engagement with the detent pin168. Once this state has been reached, further rotation of the blocking element134about the piston longitudinal axis A is prevented by the mutual engagement of detent teeth164and detent pin168. This state is reached at time t4. The brake piston114in this state is secured in its axial position inside the housing112.

Once the self-locking engagement of detent teeth164and detent pin168has been established, the energizing of the lifting magnet166may also be cancelled.

In this state, the blocking element134is locked against rotation about the piston longitudinal axis A. The brake linings126and128press with the clamping force F2upon the brake disc. The parking braking function is activated.

To cancel the parking braking function, at a time t6hydraulic fluid is fed through the hydraulic fluid line to the fluid chamber116and the hydraulic pressure in the fluid chamber116is increased from the value p0to the value p1. In said case, the clamping force rises from the value F2to the clamping force value F3. The brake piston114is mechanically uncoupled from the blocking device134. The blocking device134consequently rotates slightly, with the result that the detent teeth164and the detent pin168may move out of their self-locking engagement, displaced by the bias acting upon the detent pin168. The blocking element134is therefore no longer blocked by the planetary gear148and is rotatable inside the housing112. Subsequently, at time t10hydraulic fluid may be discharged from the fluid chamber116until the hydraulic pressure prevailing therein drops from the value p1to the value p0. In parallel, the clamping force transmitted via the brake linings126and128drops to the value F0, so that the vehicle brake110is once more in its braking-effect-free basic state shown inFIG. 2.

InFIGS. 3 and 4a third embodiment of the invention is shown. This is similar to the second embodiment according toFIG. 2. For this reason, in the following only the differences from the embodiment according toFIG. 2are described, wherein for components of identical type or identical effect the same reference characters as for the description of the second embodiment are used, only prefixed by the number “2”.

One difference is that the blocking element234is designed with a threaded bolt230, which is accommodated in an internal thread formed in the brake piston214, thereby forming a self-unlocking thread pairing. The brake piston214is guided in a rotationally fixed manner in the housing212by means of guide pins270fastened to the housing212.FIG. 3also shows the hydraulic fluid feed line218.

The blocking element234is supported rotatably about the piston longitudinal axis A in the housing212by means of the bearing arrangement238. The bearing arrangement238is secured axially by means of a piston damping element274and a locking ring276. The blocking element234extends through a wall portion272, in which it is guided in a fluid-proof manner by means of a sealing element278. On the, inFIG. 3, left end of the blocking element234a detent disk262is fitted in a rotationally fixed manner. The detent disk262is of a dish-shaped design and has on its radial peripheral region detent teeth264with recesses280, into which a detent pin268of a lifting magnet266may engage upon activation of the lifting magnet266. A plurality of such recesses280are provided over the circumference of the detent disk262.

During operation the vehicle brake210functions analogously to the vehicle brake110ofFIG. 2, wherein owing to the absence of the planetary gear higher forces act upon the detent pin268. What was said with regard toFIG. 10applies equally to the vehicle brake210. It should additionally be noted that, given a very fine pitch of the detent disk262with recesses280, the setting operations mentioned in the description inFIG. 10may be minimized and so the magnitude of the drop in the clamping force from F1to F2may be kept low.

InFIGS. 5 to 7a fourth embodiment of the vehicle brake according to the invention is shown and generally denoted by310. This embodiment is similar to the second and third embodiment according toFIGS. 2 to 4. For this reason, in the following only the differences from the embodiments according toFIGS. 2 to 4are described, wherein for components of identical type or identical effect the same reference characters as for the description of the previous embodiments are used, but prefixed by the number “3”.

In the fourth embodiment according toFIGS. 5 to 7, the blocking element334is likewise connected by a planetary gear360to the detent disk362. The planetary gear360comprises a sun wheel384fitted in a rotationally fixed manner on the blocking element, three planet wheels382meshing with the sun wheel384and supported by bearing pins390rotatably on the detent disk362serving as a planet carrier, and a sun wheel386, which is fitted in a rotationally fixed manner in the housing312and with which the planet wheels382mesh.

A further characteristic feature of the fourth embodiment according toFIGS. 5 to 7is that the detent disk362is connected by a spiral spring388to the housing312. The spiral spring388is tensioned when the brake piston314is displaced towards the non-illustrated brake disc and leads to the build-up of a resetting force, which upon release of the brake piston314returns the brake piston314actively to its basic position shown inFIG. 5.

Otherwise, the vehicle brake310is of the same design as the previously described, hydraulically actuated embodiments, in particular as shown inFIG. 3, and operates in a corresponding manner.

InFIG. 8a possible latching arrangement according to the invention is shown in detail. In this arrangement a pawl468, which is supported there by means of a bolt494rotatably in the non-illustrated housing, is biased by means of a spring492into a release position that is not shown inFIG. 8. By means of the lifting magnet466the pawl468is displaceable counter to the spring action of the spring492into its blocking position shown inFIG. 8, in which it is in engagement with internal gearing464of the detent disk462and prevents the detent disk462from rotating in direction of rotation R1. This direction of rotation R1corresponds to a cancelling of the braking effect. Rotation in the opposite direction of rotation R2, i.e. further application of the brake, is, however, possible. During cancelling of the latching, the detent disk462need merely be rotated slightly in direction R2for the pawl to be released and returned by the spring492to its detent-effect-free release position. The lifting magnet466accordingly no longer has to be activated to cancel the latching.

InFIG. 9an alternative latching arrangement according to the invention is shown in detail. This arrangement comprises two pawls5681and5682, which are biased into their release position in each case by springs5921and5922associated therewith. Both pawls5681and5682are actuated by one and the same lifting magnet566. However, the pawls5681and5682are disposed and dimensioned so in tune with the pitch of the internal gearing564that there is always only one of the pawls5681and5682in self-locking engagement with one of the teeth of the internal gearing564and the, in each case, other of the pawls5681and5682then lies between two adjacent teeth of the internal gearing564. Thus, despite a relatively coarse pitch of the internal gearing564, sufficiently fine detent positions may be provided.

The invention provides a vehicle brake, with which a service braking function may be realized in a conventional manner hydraulically or electromechanically and with which a parking braking function may be activated and/or deactivated utilizing a latching arrangement of a simple design.