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Patent Searching and Data


Title:
VEHICLE BRAKE
Document Type and Number:
WIPO Patent Application WO/2009/116928
Kind Code:
A1
Abstract:
A vehicle brake (10) comprising a brake yoke (12) provided with a brake lining (20) for braking engagement with a brake disc (54). According to the invention, the brake lining (20) is provided with a side which faces radially inwards for braking engagement with a peripheral surface (56) of the brake disc (54) by movement of the brake yoke (12) in a radial plane relative to the brake disc.

Inventors:
SUNDBERG MARTIN (SE)
BERNSTROEM ANNETTE (SE)
HARJU ROBERTH (SE)
ROGGENBUCK PHILIP (SE)
LOEFSTRAND MATS (SE)
Application Number:
PCT/SE2009/050197
Publication Date:
September 24, 2009
Filing Date:
February 23, 2009
Export Citation:
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Assignee:
SCANIA CV AB (SE)
SUNDBERG MARTIN (SE)
BERNSTROEM ANNETTE (SE)
HARJU ROBERTH (SE)
ROGGENBUCK PHILIP (SE)
LOEFSTRAND MATS (SE)
International Classes:
F16D55/22
Foreign References:
DE1288376B1969-01-30
DE4025222A11992-02-13
US2906375A1959-09-29
US3780835A1973-12-25
Attorney, Agent or Firm:
FORSELL, Hans (Patents, Södertälje, SE)
Download PDF:
Claims:

CLAIMS

1. A vehicle brake (10) comprising a brake yoke (12) provided with a brake lining (20) for braking engagement with a brake disc (54), c h a r a c t e r i s e d in that the brake lining (20) is provided with a side which faces radially inwards for braking engagement with a peripheral surface (56) of the brake disc (54) by movement of the brake yoke (12) in a radial plane relative to the brake disc.

2. A vehicle brake according to claim 1 , in which the brake yoke (12) is movable by movement of a brake bracket (30) relative to a wheelshaft member (42) connected to it.

3. A vehicle brake according to claim 2, in which the brake bracket (30) is connected to the wheelshaft member (42) via connecting means (32, 34) with radial play.

4. A vehicle brake according to any one of the foregoing claims, in which the brake lining (20) is arranged on the inside of a portion of a lining carrier (14) for axially acting brake linings (22) which straddles the brake disc (54).

5. A vehicle brake according to any one of claims 2-4, comprising an actuator (62; 70) acting between the brake yoke (12) and the shaft member (42) for said movement.

6. A vehicle brake according to claim 5, in which the actuator is a linear actuator (70).

7. A vehicle brake according to claim 5, in which the actuator comprises a worm gear (60) for moving the brake yoke via a rotatable eccentric means (36).

8. Use of a vehicle brake according to any one of the foregoing claims as a parking brake.

Description:

Vehicle brake

TECHNICAL FIELD

The invention relates to a vehicle brake comprising a brake yoke provided with a brake lining for braking engagement with a brake disc. The invention also relates to use of such a brake as a parking brake.

BACKGROUND

Such a known disc brake is used as a service brake which in trucks is also commonly used as a parking brake. In such cases, the parking brake is usually applied by means of a preloaded spring, the force of which is released by removing a counter pressure of compressed air. However, this arrangement for applying the parking brake is relatively complicated and requires a large amount of space in the axial direction.

SUMMARY OF THE INVENTION

An object of the invention is to propose a supplementary brake of the kind indicated in the introduction which is usable as a parking brake along with a conventional vehicle brake by using a common brake disc.

According a version of the invention, the brake lining is provided with a side which faces radially inwards for braking engagement with a peripheral surface of the brake disc by movement of the brake yoke in a radial plane relative to the brake disc.

Using the brake yoke in this way as part of an actuator for applying the brake in a direction perpendicular to the direction of a conventional service brake means that the brake needs only a slight amount of extra space in the axial direction when it is used in combination with such a conventional service brake.

According to an embodiment of the invention, the brake yoke is movable by movement of a brake bracket relative to a wheelshaft member connected to it.

The connection to the wheelshaft member may be achieved via connecting means with radial play. The radial play may be such that it also allows a certain eccentric rotation of the brake yoke in order to effect a self-

locking action of the brake.

The brake lining may be arranged on the inside of a portion of a lining carrier for axially acting brake linings which straddles the brake disc. This makes it possible for the brake with small modifications to be combined with a conventional axially acting disc brake.

The vehicle brake may further have an actuator which effects between the brake yoke and the shaft member the movement between applied and unapplied states of the brake.

The actuator may be a linear actuator. The actuator may alternatively comprise a worm gear for moving the brake yoke via a rotatable eccentric means. This also makes it possible for the brake yoke to be caused to pivot eccentrically for the desired self-locking of the brake.

Other features and advantages of the invention may be indicated by the claims and the description of embodiment examples set out below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified side view of a wheelshaft provided with a vehicle brake according to the invention in an unbraked state;

FIG. 2 is a view corresponding to FIG. 1 with the brake in an applied state;

FIG. 3 is a schematic sectional view to larger scale approximately along the line 3-3 in FIG. 1 ;

FIG. 4 is a schematic sectional view corresponding to FIG. 3 of a modified vehicle brake; and FIG. 5 is a schematic sectional view of the vehicle brake in FIG. 4 in an applied state.

DETAILED DESCRIPTION OF EMBODIMENT EXAMPLES The simplified depiction in FIGS. 1 and 2 shows a vehicle brake in the form of a wheel brake 10 mounted on a wheelshaft 40. The wheelshaft 40 comprises a hollow shaft member 42 in which a driveshaft 50 is supported in a manner not depicted in more detail. In the

example depicted, the shaft member 42 also has an end portion 46 extending through the brake 10. A hub sleeve 52 firmly connected to a brake disc 54 is supported for rotation on the end portion 46.

In the example depicted, the brake 10 comprises in a known manner an axial disc brake. The disc brake has a brake yoke 12 which is connected to the shaft member 42 via a brake bracket 30. As indicated in more detail in FIGS. 3-5, the brake yoke 12 in the examples depicted comprises also a lining carrier 14. The lining carrier 14 straddles the brake disc 54 from above and has on both sides of the brake disc 54 recesses 16 (only one is depicted) for accommodating brake linings 22 (FIG. 1 ) so arranged that braking causes them in a known manner to be applied in the axial direction to opposite planar sides of the brake disc 54. The brake yoke 12 may in a likewise known manner have an undepicted floatingly supported yoke saddle which via a brake piston effects the application of the brake linings 22 on both sides. The brake 10 comprises also according to the invention a radial disc brake with brake linings 20 which can be applied in the radial direction to the peripheral surface 56 of the brake disc 54. Although various other arrangements may be conceivable, a pair of brake linings 20 in the embodiment example depicted are arranged at sides 18 of the lining carrier 14 which face radially inwards (FIGS. 3-5); more specifically, the inward-facing sides 18 are situated on the portions of the lining carrier 14 which straddle the brake disc 54.

The radial disc brake is applied in the radial direction in the embodiments depicted by the brake yoke 12 being moved vertically downwards with respect to the wheelshaft member 42. To this end, the brake bracket 30 is floatingly supported in the radial direction. This may achieved by the brake bracket 30 being movably connected to the shaft member 42 via connecting means with radial play. To this end, the brake bracket 30 has a pair of enlarged apertures 32 (FIGS. 3-5) through which the brake bracket 30 is connected by a pair of spigots 34, e.g. screw spigots, so that the brake bracket 30 can move along the enlarged apertures 32, downwards for brake application and upwards for brake release, and can also pivot to a limited extent.

The movement may be effected by various types of actuator. The embodiment according to FIG. 2 depicts by way of example a linear actuator 70

which can effect the vertical movement. The actuator 70 has its lower end connected articulatedly to the shaft member 42 and its upper end connected articulated Iy to some suitable portion of the brake yoke 12.

In the embodiment according to FIGS. 4 and 5, the movement is achieved by rotation of an eccentric means 36. The eccentric means 36 has a circular outer periphery supported for rotation in a corresponding aperture in the brake bracket 30, and has, eccentric thereto, a circular inner periphery supported for rotation relative to a circular outside of the end portion 46 of the shaft member. Rotary movement of the eccentric means 36 from the position in FIG. 4 to the position in FIG. 5 will cause the brake bracket 30 to move downwards (and also sideways) so that the brake linings 20 come into braking engagement with the periphery 56 of the brake disc 54. As schematically indicated in FIG. 4, the rotary movement may be effected by means of a worm gear 60 driven by an actuator in the form of an electric motor 62 whereby there is worm gear engagement between the output shaft 64 of the electric motor 62 and the outside of the eccentric means 36. The electric motor 62 may be connected to an element 74 which is firmly connected to the end portion 46 of the shaft member. To compensate for the diameter differences during the rotary movement, the motor 62 or the shaft 64 may in an undepicted manner be elastically preloaded towards the eccentric means 36. Alternatively, the eccentric means 36 may of course have, for engagement with the worm gear, a toothed rim which is not eccentric but centric to the brake disc 54 (not depicted).

The enlarged apertures 32 not only allow a vertical movement of the brake yoke 12 but also allow the brake yoke 12 to pivot slightly about an eccentric pivot axis E (FIG. 5) for the outside diameter of the eccentric means 36. The pivot axis E is therefore eccentric to the axis of rotation B of the brake disc. The result is a self-acting braking action of the radial disc brake, i.e. the braking force increases with increasing torsional moment on the brake disc 54 in any desired braking direction.

In the embodiment described above according to FIGS. 2 and 3 with the actuator 70 (FIG. 2) there is no eccentric means, but the brake yoke 12 can, when it is pressed down and applying the brake, be allowed to pivot

eccentrically owing to the play in the apertures 32 (FIG. 3), thereby making it possible to achieve the desired self-action of the brake.

To reliably prevent the brake yoke from pivoting when the radial disc brake is not applied, recesses 38 (FIGS. 3-5) in the brake bracket 30 may engage with protrusions 48 on an axially protruding portion 44 of the shaft member 42. The recesses 38 and the protrusions 48 have with advantage angled lateral flanks so that they can also cooperate to pivot the brake yoke 12 back from the position in FIG. 5 to the position in FIG. 4 (or FIG. 3) when they again come into mutual engagement upon release of the radial disc brake by means of the actuator 62 or 70.

The description set out above is primarily intended to facilitate comprehension and no unnecessary limitations of the invention are to be inferred therefrom. The modifications which will be obvious to one skilled in the art from perusing the description may be implemented without deviating from the concept of the invention or the scope of the claims set out below.