GB2158531A

GB2158531A - Brake pad carrier

Info

Publication number: GB2158531A
Application number: GB08511533A
Authority: GB
Inventors: Mathias Schorwerth
Original assignee: KNORR BREMSE GmbH; Knorr Bremse AG
Current assignee: KNORR BREMSE GmbH; Knorr Bremse AG
Priority date: 1984-05-11
Filing date: 1985-05-07
Publication date: 1985-11-13
Also published as: IN162377B; GB2158531B; DE3417600A1; GB8511533D0

Abstract

Carrier 1 for use in disc brake assembly has guideway(s) on under side of the carrier 1 and along and/or into and out of which a brake pad 3 is movable for mounting and de-mounting the brake pad relative to the carrier, and a pad holder 5 in the form of a pivotable mounting engageable with the brake pad in order to retain the latter in the guideway(s). The mounting 5 is movable between a pad-release position and a pad-holding position, and blocking part 15 on the holder 5 is arranged to extend through an opening 23 in the carrier and to block withdrawal of the brake pad 3, from the guideway(s) after mounting of the brake pad therein and upon movement of the pad holder 5 to the pad-holding position, the holder 5 is mounted to permit generally pivotal or rocking movement of the pad holder 5 between its release position and its holding position. As shown, holder 5 is mounted by screw bolts 19 extending through conically widening bores 17 in side parts 11 and into bores in brackets 7, 9 the mounting 5 e.g. carries out pivotal or rocking movement as bolts 19 are screwed into brackets 7, 9. Cup springs (not shown) can be introduced between heads of bolts and mounting 5. One or both bores in brackets may be threaded - instead counter head or nut may be provided - in Figure 5 only one bracket (28) is provided. In Figures 1-5 the dovetail guideways run in longitudinal direction of carrier; in Figure 6,7 they run in transverse direction and hooked part (31) on holder (5) cooperates with dovetail. <IMAGE>

Description

SPECIFICATION Brake Pad Carrier for Use in Disc Brake Assembly This invention relates to a brake pad carrierfor use in a disc brake assembly and which comprises a guideway on one side of the carrier and along and/or into and out of which a brake pad is movable for mounting and de-mounting the brake pad relative to the carrier, and a pad-clamping device mounted on the opposite side of the carrier and engageable with one end of the brake pad in order to retain the latter in the guideway.

The invention has been developed primarily, though not exclusively, in relation to a brake pad carrier for use in a disc brake assembly for a rail vehicle. However, it should be understood that a brake pad carrier according to the invention may be provided for use in disc brake assemblies in other vehicles or braking environments.

It is known from DE-PS2 213 049 and DE PS2 841139 to retain a brake pad assembly on a brake pad carrier by means of pivotable tie rods which are pivotably mounted on the upper side of the brake pad carrier by means of a journal or the like and which, in their closure position, cross the mouth of the pad guideway, and are pivotable into a release position. A closure tie rod of this type is generally guided between two pairs of brackets, wherein one pair of brackets is used for receiving the journal pin for the closure tie rod, whilst the other pair of brackets is used for arresting the end of the closure tie rod that is pivotable between the brackets.

With closure tie rods of this type, whose axis of rotation extends substantially parallel to the longitudinal axis of the brake pad carrier, a secure blocking of the brake pad is possible in its brake pad guideway on the underside of the brake pad carrier.

The brake pad is thus inserted in guideways existing on the underside of the brake pad carrier, with the aid of a pad plate constructed on it, which guideways can be constructed, for example, as dovetail guideways running in the longitudinal direction. The projection of the closure tie rod into the mouth of the brake pad guidewaycertainly prevents an automatic release of the brake pad, but it can not be ruled out that there is a specific clearance, i.e. that the brake pad can make striking movements in the longitudinal direction and/or transverse direction. This can lead both to undesirable noise and also to increased wear; also the closure tie rod itself can be loaded in an undesirable way.

The present invention therefore seeks to provide a brake pad carrier in which not only secure blocking or holding of the brake pad in the guideway can be achieved, but also in which more rigid mounting of the brake pad can be obtained. Accordingly, the same advantages as obtained by the use of undetachable tie rod devices can be retained, as they are in closure tie rods rotatable in the transverse direction as known per se. Also, in a preferred aspect of the invention, it should also be possible to change over or modify existing designs of brake pad carriers, provided for closure tie rods of the type mentioned, without requiring costly adaptation work, to obtain a brake pad carrier with the features of the invention.

According to the invention there is provided a brake pad carrier for use in a disc brake assembly and comprising: a guideway on one side of the carrier and along and/or into and out of which a brake pad is movable for mounting and de-mounting the brake pad relative to the carrier; and a pad-clamping device mounted on the opposite side of the carrier and engageable with one end of the brake pad in order to retain the latter in the guideway, said clamping device comprising: a pad holder which is movably mounted on said opposite side of the carrier for movement between a pad-release position and a pad-holding position; a projecting portion on said holder which is arranged to extend through an opening in the carrier and to block withdrawal of the brake pad from the guideway after mounting of the brake pad therein and upon movement of the pad holder to the pad-holding position; and means mounting the pad holder on the carrier to permit generally pivotal or rocking movement of the pad holder between its release position and its holding position about an axis which extends generally perpendicular to the longitudinal axis of the guideway.

Preferably, the mounting means comprises threaded fasteners which extend through the pad holder and into engagement with brackets fixed to the carrier, the arrangement of these threaded fasteners being such as to permit the holder to pivot or rock to, and then to be clamped in its holding position. Advantageously, the required combined movement of the pad holder is achieved by tightening of the threaded fasteners which permit the pivoting or rocking movement of the pad holder.

In a preferred embodiment, the pad holder is held securely on the upper side of the brake pad carrier by means ofthreaded fasteners in the form of screw bolts located in engagement with the brackets, and this guarantees an undetachable retention. At the same time, it is possible to carry out a specific superimposed movement to the effect that the pad holder can not only project into the mouth of the brake pad guideway, but also that at the same time a specific axial (compressive) clamping force can be exerted with respect to the brake pad.The brake pad guideway may comprise dovetail profiles extending in the longitudinal direction, and a pad-blocking part which may be provided on the pad holder can abut against a rectangular end face of the brake pad, when in the blocking position, whereby a specific axially directed force component can have an effect with respect to a backing plate on which the pad is carried. The pad holder may also be used for brake pad carriers ofthe construction in which rectangular profiles running in the longitudinal direction are provided for the pad guideway, while the dovetail profiles are provided on the front faces. In this case the blocking part on the pad holder replaces one of the front dovetail guideways and engages in hooklike manner a wedge-shaped pad backing plate.

Instead of the screw bolts, other threaded fasteners and other securing elements can also be used, of course, and they can be screwed to the brackets on the upper side of the brake pad carrier, or can be secured to this in some other way. In a particularly advantageous embodiment, the pad holder may also be used with existing brake pad carriers (suitably modified) which until now had been provided for conventional, rotatable closure tie rods of the known type. In this case, it is merely necessary to bore out and/or tap the already existing brackets or pairs or brackets, correspondingly to receive the screw bolts.

Embodiments of brake pad carrier according to the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a partial plan view of a brake pad carrier according to the invention; Figure 2 is a section taken on the line Il-Il in Figure 1, and showing a brake pad holder in a holding position; Figure 3 is a sectional view, similar to Figure 2, but showing the pad holder in a released position permitting mounting and de-mounting of the brake pad; Figure 4 is a front view, seen from the right in Figure 2, showing detailed construction of the pad holder; Figure 5 is a plan view, similar to Figure 1, of a further embodiment of brake pad carrier according to the invention;; Figure 6 is a partial sectional view of a brake pad carrier having a different construction of guideways for the brake pad, and a modified construction of pad holderto cooperate therewith; and Figure 7 is a sectional viewtaken on the lines Vil-Vil in Figure 6.

In Figure 1 of the drawings, there is shown in partial plan view a brake block assembly which is formed by a brake pad carrier 1 and a brake pad 3 (Fig. 2 and Fig. 3). On the underside of the brake pad carrier 1 there is provided a guidewayforthe brake pad 3 which comprises two dovetail shaped guideways (see Fig. 4) running in the longitudinal direction of the brake pad carrier on the underside of the same, into which guideways the brake pad is inserted in the longitudinal direction.After insertion of the brake pad 3 into the guideways located on the underside ofthe brake pad carrier, one end ofthe brake pad abuts the end region of the brake pad carrier 1 (not shown in Figure 1), whilst the opposite end of the brake pad can be arrested with the aid of a pad holder in the form of a pivotable mounting 5 in the manner described below. The brake pad carrier shown in Fig. 1 corresponds to an embodiment which, according to the construction, was originally conceived for use with a pivotable transverse tie rod. For this purpose, two pairs of brackets 7 and 9 are provided on the facing upper side (Figure 1) of the brake pad carrier.The brackets 7 and 9 were originally used in a brake pad carrier of this type for receiving a known type of pivotable closure tie rod, one end of which is pivotably mounted between one of the pairs of brackets 7, 9, whilst the other end can be arrested between the other pair of brackets 7. 9.

In the embodiment of the invention shown in Fig.

1, instead of the pivotable tie rod of the above known type, there is used the pivotable mounting 5 which can be braced with the aid of the brackets 7 and 9. The pivotable mounting 5, in the construction seen in Figs. 1-4, comprises substantially two side parts 11, one central part 13 and one downwardly directed blocking part 15 jutting-out from the central part according to Figs. 2 and 3. The two side parts 11 are provided respectively with a conically widening bore 17, and threaded fasteners e.g. screw bolts 19 extend through the two bores. The screw bolts can be screwed into the brackets 7, 9 and are thus able to brace the pivotable mounting 5 with respect to the brake pad, as is described below.

The brake pad 3 insertable on the underside of the brake pad carrier has a so-called pad (backing) plate 21 which is used for inserting into the guideways on the brake pad carrier, and has a configuration adapted to the shape of the guideways. The front view of Fig. 4 makes it clearthat in the embodiment shown in Fig. 1 dovetail guideways are provided on the underside ofthe brake pad carrier.

Consequently, the pad plate 21, which according to Fig. 1 can be inserted in a right-to-left direction, is provided with corresponding dovetail-shaped configuration. If the brake pad 3 is completely inserted with its pad plate 21 into the guideways of the brake pad carrier, then the brake pad can be fixed in its position with the aid of the pivotable mounting 5. For this purpose the two screw bolts 19, proceeding from the position of Fig. 3, are screwed into the bores of the brackets 7 and 9, and hence the pivotable mounting 5 carries out a superimposed, generally pivotal or rocking movement so that the blocking part 15 engages from the top through an opening 23, which penetrates the brake pad carrier between the brackets 7 and 9 in the transverse direction.The blocking part 15 thus adjoins the end surface 25 on the right-hand end of the brake pad 21 according to Figs. 2 and 3, and in this way fixedly retains the brake pad. The two screw bolts 19 are screwed so far into the brackets 7 and 9, during this pivoting of the pivotable mounting 5 that there is now the distance b (Fig. 2) with respect to the original distance a (Fig. 3) for the two screw heads. If the pivotable mounting 5 is in the position shown in Fig. 2, then a nose 27 projecting from the central part 13 lies on an abutment on the upper side of the brake pad carrier adjacent to the opening 23; a further pivoting movement is thus prevented, and at the same time, by a further rotation of the screw bolts 19, an exclusively axially directed compressive clamping force can be exerted. Furthermore, additional spring elements (not shown), for instance cup springs, can be introduced between the heads of the screw bolts and the pivotable mounting 5 so as to achieve a resilient bracing or clamping of the brake pad in the guideways of the brake pad carrier.

The above described design and function of the pivotable mounting prove to be of particular advantage in the case of brake pad carriers of the construction shown in Fig. 1, since it is possible to change-over or modify in simple fashion brake pad carriers of this type, originally provided for known pivotable transverse tie rods.

Normally both the brackets 7 and 9 are constructed as simple through bores which are used to receive a pivotable bolt or an arresting pin. If the brake pad carrier is to be changed over to use with a pivotable mounting, as shown in Figs. 1-4, then it is merely necessary to tap the already present brackets 7 and 9 with an inner thread to receive the screw bolts 19, since previously the originally present pivotable cross tie rod has been removed. If need be it is also sufficient merely to equip one of the brackets, preferably the wider one, with an inner thread for the screw bolts. In certain circumstances it is also possible to do without inner threads in the bores of the two brackets 7 and 9, and instead of this to guide the two screw bolts 19 through the brackets so that they can be screwed with a counter head or with a nut.The "tightening" of the screw bolts can therefore also be carried out from the opposite end.

It was shown above that the bores 17 in the side parts 11 receiving the screwbolts are constructed to be conically widening. This is necessary, as provided in comparing Figs. 2 and 3, so that the pivoting (rocking) movement of the pivotable mounting 5 is possible around an imaginary centre point. Other possibilities are of course, also given so as to make possible a pivoting movement of this type. Thus it is also possible that the stem of the two screw bolts 19 has a circumferential groove which, in conjunction with the inner bore in the associated side part 11, allows a pivoting movement of the pivotable mounting.

Fig. 5 shows an embodiment of the invention in which the brake pad carrier is designed particularly for the concept of the pivotable mounting. Instead of two brackets 7 and 9, brackets 28 of the throughgoing construction are provided. The screw bolts 19 accordingly extend in corresponding threaded bores of the two brackets 28. Thus it is also possible that instead of the screw bolts 19, throughgoing bolts are used which extend through throughbores into the brackets 28, and are in threaded engagement with a counter head or with a nut. As in the case of the embodiment of Figs. 1-4, with the construction of Fig. 5 also it is possible to insert the brake pad into the longitudinal guides of the brake pad carrier, if there is a position comparable to Fig. 3 in which the pivotable mounting is pivoted out of the blocking position with respect to the pad plate 21.

The pivoting-out of the pivotable mounting 5 can thus be accomplished manually in simple manner whilst the pivoting-into the blocking position of Fig.

2 occurs automatically because of the leverages existing. Of course it is also immediately possible to pivot the pivotable mounting, proceeding from the position of Fig. 3, first of all manually into the blocking position with respect to the pad plate, so as then to carry out the further bracing by screwing with the aid of the screw bolts 19, as explained above. It is therefore directly possible that the changing of the brake pad can be carried out by one single person, since he/she can on the one hand push in or push out the brake pad, and on the other hand is in the position at any time to pivot the pivotable mounting manually into the desired position after the screw bolts have occupied their released position according to Fig. 3.

In Figs. 6 and 7 the use of the pivotable mounting is shown in the case of a brake pad carrier construction in which the dovetail guideways at both sides of the backing plate for the brake pad do not extend in the longitudinal direction on the underside of the brake pad carrier, but run in the transverse direction. With a construction of this type, the backing plate 29 (Fig. 7), whose edges are made to be rectangular, abuts correspondingly rectangular shaped guideways on the underside of the brake pad carrier. Falling-out of the brake pad is thus prevented with this construction by the fact that the two front sides of the backing plate are not made to be rectangular, but dovetail-shaped or angled, as can be seen in the partial sectional view of Fig. 6.So as to make possible pad-retention and also the bracing with the aid of the pivotable mountings, this is equipped with a hooked blocking part 31 on the front side facing it, which co-operates with the transverse dovetail profile at the other end of the guideway. The blocking part thus engages with the backing plate 29. In this special embodiment of the brake pad carrier, the brake pad is therefore pushed in less, then turned in from below, whereby first of all care is taken that the left-hand end face of the brake pad engages into the associated dovetail guideway of the brake pad carrier. Basically even with a construction of this type one can proceed according to the above principle, so that the pivotable mounting with the hooked blocking part 31 is used to secure the brake pad assembly undetachably to the brake pad carrier located thereon, and to be able to clamp the pad assembly in position by applying an axial compression force thereon. Deflection in the area of the guideways is thus eliminated.

Claims

1. Abrake pad carrier for use in a disc brake assembly and comprising: a guideway on one side of the carrier and along and/or into and out of which a brake pad is movable for mounting and de-mounting the brake pad relative to the carrier; and a pad-clamping device mounted on the opposite side of the carrier and engageable with one end of the brake pad in order to retain the latter in the guideway, said clamping device comprising: a pad holder which is movably mounted on said opposite side of the carrier for movement between a pad-release position and a pad-holding position; a projecting portion on said holder which is arranged to extend through an opening in the carrier and to blockwithdrawal of the brake pad from the guideway after mounting of the brake pad therein and upon movement of the pad holder to the pad-holding position; and means mounting the pad holder on the carrier to permit generally pivotal or rocking movement of the pad holder between its release position and its holding position about an axis which extends generally perpendicular to the longitudinal axis of the guideway.

2. A brake pad carrier according to claim 1, in which said mounting means comprises threaded fasteners which extend through the pad holder and into engagement with brackets fixed to the carrier, the arrangement of the threaded fasteners being such as to permit the holder to pivot or rock to, and then to be clamped in its holding position.

3. A brake pad carrier according to claim 2, in which the threaded fasteners have threaded engagement with the brackets.

4. A brake pad carrier according to claim 2, in which the threaded fasteners engage the brackets via nuts on the ends of the fasteners.

5. A brake pad carrier according to claim 4, in which the pad holder comprises a central portion and side portions on either side of the central portion which are provided with conically enlarged bores through which the threaded fasteners extend with a clearance determined by the conicity of the bores, so that the side portions can carry out generally pivoting or rocking movement on the threaded fasteners, and in which said projecting portion extends from said central portion in the direction of the brake pad, whereby the projecting portion is able to project through said opening in the carrier located underneath and through and into the blocking position with respect to a backing plate for the brake pad.

6. A brake pad carrier according to claim 5, in which the threaded fasteners are arranged, upon tightening, to pivot or rock the pad holder to its holding position by virtue of a leverage action exerted thereon.

7. A brake pad carrier according to any one of the preceding claims, including a nose portion extending substantially perpendicularly of the projecting portion of the holder and in the direction of the axis of the guideway, said nose portion being engageable with an abutment on the carrier adjacent to the opening in the carrier in order to limit the pivoting or rocking movement of the holder to its holding position and thereafter to cause further movement of the holder to be axial movement in order to clamp the pad in the guideway.

8. A brake pad carrier according to any one of the preceding claims, in which the guideway has dovetail guides along its side edges which extend parallel to the longitudinal axis of the guideway.

9. A brake pad carrier according to any one of claims 1 to 7, in which the guideway has a rectangular cross section, as seen in the direction of the longitudinal axis, and has a dovetail guide at one end which extends perpendicular to the longitudinal axis of the guideway, and in which the pad holder has a dovetail profile so as to cooperate with said dovetail guide in order to retain and to clamp the pad in the guideway.

10. A brake pad carrier according to claim 2, or any one of claims 3 to 9 when appendent to claim 2, in which the brackets are of the type initially provided on an existing design of carrierto permit of clamping of the pad by use of transversely extending tie rods known per se, and in which the brackets are subsequently drilled-out and/or tapped to receive the threaded fasteners and thereby adapt the existing equipment to mount said pad holder thereon.

11. A brake pad carrier according to claim 1 and substantially as hereinbefore described with reference to, and as shown in any of the embodiments illustrated in the accompanying drawings.

12. Adisc brake assembly including a brake pad carrier according to any one of the preceding claims.