Drum brake with anchor plate noise reduction device

Abstract

Drum brake comprising an anchor plate which carries a primary shoe and a secondary shoe, each fitted with a brake lining, wherein the wheel cylinder actuates the shoes by means of an adjusting lever and a handbrake lever, wherein the brake comprises an anchor plate noise reduction device (90, 90') formed by two noise reduction elements (90A,B) each associated with a shoe (2, 2'), wherein the noise reduction element (90A,B) is formed by a flat bracket (91) conforming to the curved shape of the lining carrier (21, 21') of each shoe (2, 2'), held near its end on the side of the wheel cylinder (5) by a fastening projection (92) and on the side of the support block (86) by a clamp (83) for attachment to the block, wherein the noise reduction device (90, 90') with its two elements (90A,B, 90'A,B) is installed on the inner surface of the anchor plate (1) under the shoes (2, 2') and their parts, characterized in that the end of each element (90') on the side of the wheel cylinder (5) has an extension in the form of a cut-out sector (95') which forms a support point for the wheel cylinder (5).

Description

Field of invention

[0001] The present invention relates to a drum brake comprising an anchor plate which carries a primary shoe and a secondary shoe, each provided with a brake lining, wherein the wheel cylinder actuates the shoes by means of an adjusting lever and a handbrake lever. State of the art

[0002] Such drum brakes are already widely known.

[0003] DE 698 21 308 T2 shows a drum brake device.

[0004] The EP 2 199 638 A1 reveals a drum brake.

[0005] The well-known drum brakes have the disadvantage that their operation is noisy due to vibrations and possible noises generated by the shoes during braking. Objective of the invention

[0006] The present invention aims to develop a drum brake that is quieter than known brakes without increasing the complexity of manufacturing or the cost of the brakes to be realized. Disclosure and advantages of the invention

[0007] To this end, the object of the present invention is a drum brake of the type defined above, characterized in that it comprises an anchor plate noise reduction device formed by two noise reduction elements, each assigned to a shoe, wherein the noise reduction element is formed by a flat bracket that conforms to the curved shape of the lining carrier of each shoe, is held near its end on the wheel cylinder side by a fastening projection and on the support block side by a clamp for its attachment to the block, wherein the noise reduction device with its two elements is installed on the inner surface of the anchor plate under the shoes and their parts.

[0008] The drum brake according to the invention has the advantage that, due to the reduction of operating noise thanks to the insulation of the brake anchor plate, which prevents the transmission of the vibrations and noises of the shoes generated during braking, it has a quieter operation than known drum brakes.

[0009] The drum brake according to the invention is of a particularly simple design, since the anchor plate noise reduction device is installed in the anchor plate before the shoes, levers and other elements of the brake mechanism are attached.

[0010] According to the invention, the end of each element on the wheel cylinder side has an extension in the form of a cut-out sector that forms a wheel cylinder support.

[0011] According to an advantageous feature, the two noise reduction elements are plane-symmetric.

[0012] Although the drum brake is generally symmetrical with respect to the shoes, if the drum brake has asymmetrical shoes, the noise reduction elements conform to the general shape of the shoes without complicating the manufacturing process due to this asymmetry.

[0013] The noise reduction elements according to the invention are attached to the anchor plate, and according to one feature, each element is a stamped and bent sheet metal part, the surface of which facing the anchor plate is covered and the metal surface of which is in contact with the associated jaw. Drawings

[0014] The present invention is described in more detail below with reference to two embodiments of a drum brake, the embodiments being illustrated in the attached drawings; therein: - Fig. 1. A top view of a drum brake; - Fig. 2 a perspective view of an anchor plate noise reduction device of a drum brake, formed by two elements, - Fig. 3 a perspective view of the drum brake anchor plate equipped with the noise reduction device, - Fig. 4 a perspective view of a variant design of the anchor plate noise reduction device, - Fig. 5 a perspective view of the drum brake anchor plate, which is fitted with the noise reduction device according to Fig. 4 is provided. Description of embodiments of the invention

[0015] According to Fig. 1. The invention relates to a drum brake formed by an anchor plate which carries the brake mechanism that actuates the brake shoes, which are provided with a lining and are to be pressed against the braking surface of the drum brake, which is rigidly connected to the wheel. The drum is not shown in this figure.

[0016] The drum brake 100 consists of an anchor plate 1 that accommodates a primary shoe 2 and a secondary shoe 2', each provided with a friction lining 3, 3' which is pressed against the braking surface of the drum (not shown) by spreading the shoes 2, 2'. These shoes 2, 2' each consist of a cylindrical surface or a lining carrier 21, 21' with a curved cross-section, each provided on the outside with a brake lining 3, 3'. The cylindrical surfaces 21, 21' extend through a web 22, 22', which is connected to the mechanical actuating elements of the brake. The primary shoe 2 is equipped with an adjusting lever 6 and the secondary shoe 2' with a handbrake lever 7. The adjusting lever 6 has an adjusting device 61 at its base, which allows the wear of the linings 3, 3' to be automatically compensated. The handbrake lever 7 is connected to the handbrake cable 71.

[0017] The levers 6, 7 are connected by a rocker arm 4 and a return spring 41 to be pressed against the ends of the wheel cylinder 5. This wheel cylinder 5 is a working cylinder that activates the spreading of the levers 6, 7 and thus the pressing of the brake linings 3, 3' against the braking surface of the drum.

[0018] At the end opposite the end of the swing arm 4, the jaws 2, 2' come into contact with a support block 86.

[0019] The anchor plate 1, which accommodates and supports the above elements, has an opening 8 in the axis xx, mounting through-holes 81, projecting parts 82 forming the surfaces of the anchor plate, an access through-hole 83 for accessing the wheel cylinder 5, and a passage through-hole 84 for the handbrake cable; these various through-holes and projecting parts being located in the Fig. 3 and Fig. 5, which show the anchor plate 1 detached from its mechanisms, are more clearly visible.

[0020] According to the invention, the drum brake 100 is made of Fig. 1 equipped with an anchor plate noise reduction device 90, which consists of two noise reduction elements 90A,B, which are symmetrical with respect to the middle plane MM and are assigned to the position of the primary jaw 2 or the secondary jaw 2'.

[0021] According to Fig. 2. The noise reduction elements 90A and 90B are symmetrical with respect to the central plane MM, which is also that of the drum brake 100. Therefore, the following description of elements 90A and 90B is limited to that of element 90A. The description of element 90B is derived from this description by simply replacing the reference numerals, by substituting the suffix "A" used for the parts of element 90A with the suffix "B" for the corresponding parts of element 90B. The detailed description of element 90B is not repeated.

[0022] The noise reduction element 90A consists of a band-shaped flat bracket 91A made of stamped sheet metal, which is provided with a cover and carries a mounting lug 92A. The mounting lug 92A is provided with a mounting hole 921A and, at one end, with a clamp 94A, which is connected to the flat bracket 91A by a curved leg 93A in order to raise the clamp 94A above the plane of the flat bracket 91A. The holes 921A,B serve to fasten the noise reduction elements 90A,B of the anchor plate to a pin 85 of the anchor plate 1.

[0023] After the noise reduction elements 90A,B are attached to the anchor plate, the jaws 2, 2' and the other elements of the drum brake mechanism are installed; the jaws 2, 2' being pressed against the noise reduction elements 90A,B in the rest state and during operation of the drum brake.

[0024] The variant of the anchor plate noise reduction device 90' ​​differs from the first embodiment solely in the shape given to the end of the flat brackets 91A,B on the side of the wheel cylinder 5. Each element 90'A,B has a cut-out sector 95'A,B at the end of the flat bracket 91A,B to be positioned under the support surface of the wheel cylinder 5 with the holes 951'A,B for the mounting screws of the wheel cylinder 5, as well as a large cutout 952'A,B for access to the wheel cylinder 5. The other parts are identical and bear the same reference numerals.

[0025] Fig. Figure 5 shows the installation of the armature plate noise reduction device 90' ​​in the armature plate 1 of the drum brake.

[0026] As a rule, the suffixes “A” and “B” are not systematically repeated in the reference numerals used in the claims. REFERENCE MARK LIST 100 drum brakes 1 anchor plate 2 Casserole / Primary Bake 2' Drain jaw / Secondary jaw 21 Cylindrical surface / plating support 21' Cylindrical surface / plating support 22 Primary jaw bridge 22' Secondary jaw bridge 3.3' friction lining 4 swing arms 41 Return spring 5 wheel cylinders 6 adjusting levers 61 Adjustment device of the adjusting lever 7 Handbrake device 71 Handbrake cable 8 Opening / Passage of the Axis 81 Mounting hole 82 Foreground part 83 Access passage 84 Passage for the handbrake cable pull 85 cones 86 Support block 90, 90' Anchor plate noise reduction device 91 Flat temple 92 Support approach 93 Curved thigh 94 bracket 941, 942 pages of the bracket 95' Cut-out sector 951' Hole 952' excerpt

Claims

[1] Drum brake comprising an anchor plate which carries a primary shoe and a secondary shoe, each provided with a brake lining, wherein the wheel cylinder actuates the shoes by means of an adjusting lever and a handbrake lever, wherein the brake comprises an anchor plate noise reduction device (90, 90') formed by two noise reduction elements (90A,B) each associated with a shoe (2, 2'), wherein the noise reduction element (90A,B) is formed by a flat bracket (91) conforming to the curved shape of the lining carrier (21, 21') of each shoe (2, 2'), held near its end on the side of the wheel cylinder (5) by a fastening projection (92) and on the side of the support block (86) by a clamp (83) for attachment to the block, wherein the noise reduction device (90, 90') with its two elements (90A,B, 90'A,B) is installed on the inner surface of the anchor plate (1) under the shoes (2, 2') and their parts, characterized by , that the end of each element (90') on the side of the wheel cylinder (5) has an extension in the form of a cut-out sector (95') which forms a support point for the wheel cylinder (5). [2] Drum brake according to claim 1, characterized by , that the two noise reduction elements (90A,B, 90'A,B) are plane-symmetric. [3] Drum brake according to claim 1, characterized by , that each element (90A,B, 90'A,B) of the noise reduction device (90, 90') is a sheet metal part whose surface facing the anchor plate (1) is covered and whose metal surface is in contact with the associated jaw (2, 2').

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