Bell for brake disc with integrated auxiliary brake

Abstract

A bell for brake disc with integrated drum-in-hat auxiliary brake. The bell (2) includes an annular flange (5) configured to be coupled to a braking band (4) of a brake disc (1), and a drum (6) coupled coaxially to the annular flange (5), wherein the drum (6) accommodates or is configured to accommodate an auxiliary brake (7). The annular flange (5) and the drum (6) are separate elements joined together. The annular flange (6) has at least one recess (13). The drum (6) comprises a cylindrical body (14) and an auxiliary annular flange (15) positioned on a peripheral edge of the cylindrical body (14). The recess (13) has an annular shape coaxial with a common symmetry axis (X-X) and houses the auxiliary annular flange (15).

Claims

1. A bell for a brake disc with an integrated drum-in-hat auxiliary brake, the bell comprising: an annular flange configured to be coupled to a braking band of the brake disc, wherein the annular flange includes outer faces on opposite sides of the annular flange; a drum coupled coaxially to the annular flange and including a cylindrical body and an auxiliary annular flange extending from a peripheral edge of the cylindrical body, wherein the drum accommodates or is configured to accommodate an auxiliary brake, wherein the annular flange and the drum are separate elements joined one to the other; and wherein the drum and the annular flange are made of different materials; and at least one annular recess in one of the outer faces of the annular flange; wherein the auxiliary annular flange seats in the at least one annular recess and the auxiliary annular flange is separable from the at least one annular recess; and wherein the auxiliary annular flange and the at least one annular recess share a common axis.

2. The bell according to claim 1, wherein a first radially peripheral edge of the annular flange has a plurality of first passages; wherein a second radially peripheral edge of the auxiliary annular flange has a plurality of second passages; wherein each of the first passages is axially aligned with a respective second passage to delimit a respective single axial passage through the annular flange and the auxiliary annular flange.

3. The bell according to claim 2, wherein the first passages and the second passages have respective notches or cuts formed respectively on the first radially peripheral edge and on the second radially peripheral edge.

4. The bell according to claim 1, wherein the annular flange is made of a light alloy and the drum is made of steel or cast iron.

5. A brake disc comprising: the bell according to claim 1, and a braking band radially external thereto, wherein the braking band and the bell extend around a common symmetry axis.

6. The brake disc according to claim 5, further comprising connecting devices operatively coupled to the braking band and to the bell, to rigidly link the braking band to the bell; wherein each of the connecting devices is placed in a first passage and in a second passage aligned with each other.

7. The brake disc according to claim 5, wherein the braking band is made of composite material; wherein the bell is metallic and is at least partly co-molded on the braking band.

8. A braking system comprising: a brake caliper, the brake disc according to claim 5, and an auxiliary brake located within the drum of the brake disc.

9. The brake system according to claim 8, wherein the auxiliary brake comprises at least one jaw configured, when the auxiliary brake is actuated, to act against an inner surface of the bell to exert a braking force by friction.

Description

SUMMARY OF THE DRAWINGS

(1) Hereinbelow the description will, as a non-limiting example, refer to the enclosed drawings in which:

(2) FIG. 1 illustrates a bell for a brake disc provided with an integrated drum-in-hat auxiliary brake according to the present invention;

(3) FIG. 2 is an exploded view of the bell of FIG. 1;

(4) FIG. 3 shows a sectional view of the bell pursuant to FIGS. 1 and 2 associated with a drum-in-hat auxiliary brake and with a braking band;

(5) FIG. 4 is an enlargement of the bell of FIG. 3; and

(6) FIG. 5 is an enlargement of a portion of FIG. 1.

DETAILED DESCRIPTION OF AN EMBODIMENT(S) OF THE INVENTION

(7) With reference to FIG. 3, the numeric reference 1 overall indicates a brake disc for drum-in-hat braking systems according to the invention.

(8) The brake disc 1 comprises a bell 2 and a braking band 3 radially external thereto. The bell 2 and the braking band 3 are extended around a central symmetry axis X-X.

(9) The braking band 3, made of composite material such as of carbon-ceramic type, is provided with two lateral braking surfaces indicated with 4, which are adapted to be engaged with a brake caliper (not shown since this is per se known) of a disc braking system.

(10) The bell 2 is metallic and is made of two pieces with two different materials. In particular, the bell 2 comprises an annular flange 5 made of aluminum and a drum 6 made of steel or cast iron (illustrated separate in FIG. 2). The annular flange may be superficially protected, such as by anodizing. The drum 6 is made of stainless steel or of cast iron protected from corrosion by means of varnishing.

(11) The annular flange 5 is configured for being directly coupled to the braking band 3. The drum 6 is coupled coaxially to the annular flange 5 and is configured to accommodate an auxiliary brake 7 (illustrated in FIG. 3 and detailed hereinbelow). As is visible in the enclosed figures, the annular flange 5 and the drum 6 are separate elements that are coupled together.

(12) The annular flange 5 has a central hole 8 and a plurality of through fixing holes 9 arranged around the central hole 8 and adapted to allow the fixing of the bell 2 and hence of the brake disc 1 to a hub of a wheel, not illustrated.

(13) The annular flange 5 also has a plurality of auxiliary small through holes 10 located in a radially more external position with respect to the fixing holes 9.

(14) A plurality of first passages 11, defined by notches or cuts, are formed on a first radially peripheral edge of the annular flange 5 (FIG. 2). In the illustrated non-limiting embodiment, each notch 11 is radially open outward and is radially extended from the abovementioned edge towards the symmetry axis X-X. Each notch also has a substantially rectangular shape with rounded inner edges. Two adjacent first passages 11 delimit a tooth between them that is extended for an arc of a circle. In the illustrated embodiment, the annular flange 5 has ten first passages 11 and ten teeth. A notch with arc of a circle shape 12 is also made on each tooth.

(15) On one of the two faces of the annular flange 5, an annular recess 13 (visible in FIGS. 3 and 4) is made which is continuously extended around the symmetry axis X-X. The annular recess 13 has a depth, measured along an axial direction, i.e. parallel to the symmetry axis X-X, constant and equal to about half of a thickness of the annular flange 5. The annular recess 13 is partly extended on the teeth delimited by the first passages 11, i.e. it has a maximum (radially outer) diameter greater than an inner diameter of the first passages 11. The annular recess 13 has a minimum (radially inner) diameter smaller than a diameter of a circumference on which the auxiliary small holes 10 are positioned and greater than a diameter of a circumference on which the fixing holes 9 are positioned. In addition, the annular recess 13 does not interfere with the notches with arc of a circle shape 12, i.e. it remains in a radially more internal position with respect to said notches with arc of a circle shape 12 (FIG. 4). The first passages 11 are partially open in said at least one annular recess 13.

(16) The drum 6 made of steel or cast iron is defined by a single piece which comprises a cylindrical body 14 and an auxiliary annular flange 15 positioned on a peripheral edge of the cylindrical body 14. The cylindrical body 14 is extended coaxially around the symmetry axis X-X and the auxiliary annular flange 15 lies in a plane orthogonal to said symmetry axis X-X on a head end of the cylindrical body 14. A maximum (radially outer) diameter of the auxiliary annular flange 15 is greater than an average diameter of the cylindrical body 14 and a minimum (radially inner) diameter of the auxiliary annular flange 15 is smaller than the average diameter of the cylindrical body 14. In other words, the cylindrical body 14 is connected to the auxiliary annular flange 15 in a radially intermediate zone thereof.

(17) The auxiliary annular flange 15 has an outer diameter smaller than or equal to an outer diameter of the annular flange 5. The auxiliary annular flange 15 also has an inner diameter greater than an inner diameter of the annular flange 5.

(18) The auxiliary annular flange 15 has a plurality of second passages 16, defined by notches or cuts, formed on a second radially peripheral edge belonging to the auxiliary annular flange 15 (FIG. 2).

(19) In the illustrated non-limiting embodiment, each notch 16 is radially open outward and is radially extended from the abovementioned second edge towards the symmetry axis X-X. Each notch 16 also has a substantially rectangular shape with rounded inner edges. Two adjacent second passages 16 delimit a tooth between them which is extended for an arc of a circle. In the illustrated embodiment, the auxiliary annular flange 15 has ten second passages 16 and ten teeth.

(20) The auxiliary annular flange 15 also has a plurality of small through holes 17 located around a central opening 18 of the drum 6 and at a radially inner edge of the auxiliary annular flange 15.

(21) The auxiliary annular flange 15 is counter-shaped with respect to the annular recess 13 and, when the bell 2 is mounted, it is accommodated in said annular recess 13. The maximum (radially outer) diameter of the auxiliary annular flange 15 is therefore about equal to the maximum (radially outer) diameter of the annular recess 13. The minimum (radially inner) diameter of the auxiliary annular flange 15 is therefore about equal to the minimum (radially inner) diameter of the annular recess 13. The auxiliary annular flange 15 has a thickness equal to about the depth of the annular recess 13 and, when it is accommodated in the annular recess 13, it lies flush with an outer surface of the flange 5.

(22) When the bell 2 is mounted, with the auxiliary annular flange 15 positioned in the annular recess 13, each of the small through holes 17 is aligned with a respective auxiliary small though hole 10 and screws 19 and pins 20 are located in said small holes 10, 17 and traverse the annular flange 5 and the auxiliary annular flange 15 in order to join them together and prevent rotary and axial movements (FIGS. 2, 3 and 4). As is visible in FIG. 1 and better illustrated in FIG. 5, the second passages 16 have the same shape as part of the first passages 11. The auxiliary annular flange 15 has, at the second passages 16, an outer diameter equal to an outer diameter presented by the annular flange 5 at the first passages 11.

(23) In the assembled configuration of the bell 2, each of the first passages/notches 11 is axially aligned with a respective second passage/notch 16 in order to delimit a respective single axial passage 21 through the annular flange 5 and the auxiliary annular flange 15. As is better visible in FIG. 5, an axial relief 22 belonging to the radially outer edge of the teeth of the annular flange 5 is placed in a radially outer position with respect to a radially outer edge of the teeth of the auxiliary flange 15.

(24) The annular flange 5 and the auxiliary annular flange 15, once coupled together, form an overall single annular flange configured for being coupled to the braking band 4. For such purpose, the single axial passages 21 are configured for being coupled with connecting devices, e.g. screws, bolts, rivets, operative between the bell 2 and the braking band 4, i.e. configured for joining the braking band to the bell and withstanding the mechanical and/or thermal forces and torques during operation (during braking). Such connecting devices were only schematically represented through their axes Y in FIG. 3. The connecting devices are accommodated in the single axial passages 21 and axially they tighten together radially inner portions of the braking band 4 and radially outer portions of the abovementioned overall single annular flange.

(25) The auxiliary brake 7 of the drum-in-hat braking system is accommodated within the drum 6, as illustrated in FIG. 3. The auxiliary drum brake 7, of known type and therefore not illustrated in detail, comprises a support plate 23 configured for being integrally mounted on the vehicle. The support plate 23 bears a pair of jaws or brake shoes 24, of which only one is schematically represented in FIG. 3, whichwhen the auxiliary brake 7 is actuatedact against a radially inner surface 25 of the bell 2 in order to exert a braking force by friction.

(26) The braking system of drum-in-hat type is therefore formed by the illustrated brake disc 2, 4, by the non-illustrated brake caliper, and by the auxiliary drum brake 7.

(27) In an alternative and non-illustrated embodiment, the bell 2 is at least partially co-molded on the braking band 4 and a radially inner portion of the braking band 4 is inserted in each of the single axial passages 21. In this case, the use of connecting devices, e.g. screws, bolts, rivets, is not required.

(28) While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.