GB2560763A

GB2560763A - Brake calipers

Info

Publication number: GB2560763A
Application number: GB1704732.5A
Authority: GB
Inventors: M Blackwell Anthony; Thomas Philip; R Mutch-Mathieson Daniel; Holloway Karly; Stevens Nicholas; Tait Jon
Original assignee: Liberty Vehicle Tech Ltd
Current assignee: Liberty Vehicle Tech Ltd
Priority date: 2017-03-24
Filing date: 2017-03-24
Publication date: 2018-09-26
Anticipated expiration: 2037-03-24
Also published as: GB2560763B; GB201704732D0

Abstract

Disclosed is a brake caliper 100 having a fixed part for attachment to a vehicle and a floating part movably mounted to the fixed part. The floating part includes a pair of spaced apart limbs 30, 31 and a bracing abutment. One of the limbs has an actuation means to apply a brake force for clamping, between the limbs, a pair of brake members 62a, 62b against a rotating disc. On application of a brake force by actuation means (which may be a piston), rotation of the brake disc exerts a drag force on the brake members, which causes at least one of them to brace against the bracing abutment. Each brake member may have their own respective bracing abutment. The limbs may be connected by a pair of bridging portions 32. The fixed and floating parts may be slidably connected by a drag force transmission pin which is orthogonal to the limbs and slidable within a bore (which is within first guide portion 40 in figure 9). The slidable connection may also include a guide pin secured within a bore (within second guide portion 50 in figure 9). The force transmission pin may be larger than the guide pin.

Description

(54) Title of the Invention: Brake calipers

Abstract Title: Floating brake caliper with bracing abutments to receive a drag force (57) Disclosed is a brake caliper 100 having a fixed part for attachment to a vehicle and a floating part movably mounted to the fixed part. The floating part includes a pair of spaced apart limbs 30, 31 and a bracing abutment. One of the limbs has an actuation means to apply a brake force for clamping, between the limbs, a pair of brake members 62a, 62b against a rotating disc. On application of a brake force by actuation means (which may be a piston), rotation of the brake disc exerts a drag force on the brake members, which causes at least one of them to brace against the bracing abutment. Each brake member may have their own respective bracing abutment. The limbs may be connected by a pair of bridging portions 32. The fixed and floating parts may be slidably connected by a drag force transmission pin which is orthogonal to the limbs and slidable within a bore (which is within first guide portion 40 in figure 9). The slidable connection may also include a guide pin secured within a bore (within second guide portion 50 in figure 9). The force transmission pin may be larger than the guide pin.

FIGURE 9

1/5

Z 23

FIGURE 3

2/5

FIGURE 6

3/5

FIGURE 7

100

3a

FIGURE 8

4/5

FIGURE 10

5/5

34a

FIGURE 11

FIGURE 12

BRAKE CALIPERS

This invention relates generally to brake calipers for vehicles. More specifically, although not exclusively, this invention relates to a disc brake caliper body and to brake calipers, braking systems and vehicles incorporating such a brake caliper body.

Conventional disc brake systems for vehicles generally include a disc coupled to the wheels, a brake caliper within which is received an outer segment of the disc and friction pads within the caliper on either side of the disc. The brake caliper includes one or more pistons reciprocable within a respective piston chamber that selectively compresses the disc between the pads to slow the vehicle.

Such brake calipers generally fall into one of two categories, namely opposed-piston calipers and reaction-type calipers. Opposed-piston calipers generally include a pair of opposed limbs, each including one or more inwardly facing pistons that are actuated to urge a respective brake pad in order to compress a brake disc received therebetween, thereby applying a braking force thereto.

Reaction-type calipers generally include a floating arm slidably mounted to a torque member fixed to the vehicle. The floating arm has one or more pistons on one of its sides, a reaction member on the other of its sides and a bridging portion extending between the sides and bridging the top of the brake disc. When actuated, the piston urges a first brake pad against the brake disc, which causes the reaction member to engage a second brake pad, drawing it toward the brake disc and compressing the brake disc between the pads to apply a braking force thereto.

One example of such a reaction-type caliper is described in US4261443, in which the torque member includes a pair of arms each of which slidably supports one side of the brake pads. When a braking force is applied, the rotation of the brake disc exerts a drag force on the brake members, which is perpendicular to the braking force and is caused by friction between the brake members and the brake disc. The torque member, for example each of its arms, provides a bracing abutment against which the brake pads braces, thereby transmitting the drag force through the torque member and to the vehicle.

The torque member is therefore subjected to considerable forces, requiring a robust construction to avoid failure. This robust construction has been found to inhibit the use of reaction-type calipers in certain applications, for example those which require a compact construction due to space constraints. Another known issue with reaction-type caliper designs is that the bridging portion of the floating arm inhibits access to the brake pads.

There is therefore a need for a brake caliper which has the advantages of reaction-type calipers, but which mitigates at least one of the aforementioned issues with its construction. There is a more general need to provide a brake caliper that overcomes, or at least mitigates one or more issues with known brake caliper designs.

Accordingly, a first aspect of the invention provides a brake caliper, for example a service brake caliper, the caliper comprising: a fixed part, e.g. for attachment to a vehicle; and a floating part, e.g. movably mounted to the fixed part, including a pair of opposed, spaced limbs and a bracing abutment, one of the limbs comprising actuation means operable to apply a brake force for clamping, between the limbs, a pair of brake members against a rotating brake disc; wherein the caliper is configured such that, on application, in use, of the brake force, rotation of the brake disc exerts a drag force on the brake members, which causes at least one of the brake members to brace against the bracing abutment of the floating part.

By configuring the floating part to include a bracing abutment for at least one of the brake members, the construction of the fixed part may be simplified. More particularly, at least a portion of the drag force generated during braking may be transmitted from the floating part to the vehicle via the fixed part, which enables flexibility in adapting the caliper for certain compact installations. In embodiments, the fixed part comprises a mounting plate, which may be adjacent the limb of the floating part with the actuation means.

Preferably, the fixed part comprises a first bracing abutment and the bracing abutment of the floating part comprises a second bracing abutment. The caliper may be configured such that, on application, in use, of the brake force, rotation of the brake disc exerts a drag force on the brake members, which causes a first of the brake members to brace against the first bracing abutment and causes a second of the brake members to brace against the second bracing abutment.

A more specific aspect of the invention provides a brake caliper comprising: a fixed part for attachment to a vehicle and including a first bracing abutment; and a floating part movably mounted to the fixed part and including a pair of opposed, spaced limbs and a second bracing abutment, one of the limbs comprising actuation means operable to apply a brake force for clamping, between the limbs, a pair of brake members against a rotating brake disc; wherein the caliper is configured such that, on application, in use, of the brake force, rotation of the brake disc exerts a drag force on the brake members, which causes a first of the brake members to brace against the first bracing abutment and causes a second of the brake members to brace against the second bracing abutment.

The limb with the actuation means may comprise a first limb and/or the other limb may comprise a second limb. The caliper may include a bridging portion, which may connect the limbs. The bridging portion may comprise the bracing abutment of the floating arm, e.g. the second bracing abutment. Alternatively, the second limb may comprise the bracing abutment or second bracing abutment. The caliper or bridging portion may include one or more, for example a pair or two or more, bridging portions. The caliper or bridging portions may comprise bridging members. The bridging portion(s) or member(s) may comprise the bracing abutment(s), e.g. the second bracing abutment(s) of the floating part. Alternatively, the second limb may comprise both second bracing abutments.

The fixed part may comprise a pair of first bracing abutments, e.g. between which the first brake member is receivable. The floating part may comprise a pair of second abutments, e.g. between which the second brake member is receivable. The first and second brake members may each brace, in use, against a respective one of the bracing abutments, e.g. when the brake disc rotates in a first direction. The first and second brake members may each brace, in use, against a respective other of the bracing abutments, e.g. when the brake disc rotates in a second direction opposite the first direction. More particularly, the first brake member may brace, in use, against a one of the first bracing abutments when the brake disc rotates in a first direction and against the other of the first bracing abutments when the brake disc rotates in a second direction opposite the first direction. Similarly, the second brake member may brace, in use, against a one of the second bracing abutments when the brake disc rotates in a first direction and against the other of the second bracing abutments when the brake disc rotates in a second direction opposite the first direction.

The caliper may comprise a pair of bridging portions or members each connecting one of the ends of the second limb to the first limb. In embodiments, each of the bridging portions includes a bracing abutment, for example one of the bracing abutments, e.g. one of the second bracing abutments. The second limb may comprises a reinforcement rib extending between the bridging portions or members, for example such that the floating part is substantially rectangular in plan, e.g. with an open top.

Thus, the floating arm may be configured to provide easy access to the brake members from above. The floating part may include one or more retaining elements for retaining the braking members in place, such as one or more, e.g. a pair of, pins and/or a resilient or spring retaining member. The retaining elements may be removable, for example to provide access to the brake members for their removal and/or replacement.

The fixed and floating parts may be connected, e.g. slidably connected, such that at least part of the drag force exerted, in use, on the brake member(s) is transmitted from the floating part to the fixed part via the connection.

The connection may comprise a drag force transmission pin, which may be substantially orthogonal to the limbs. The drag force transmission pin may be connected, mounted, fixed or secured to one of the floating and fixed parts. The drag force transmission pin may be slidably connected to, e.g. slidable within a bore in, the other of the floating and fixed parts, e.g. for transmitting at least part of the drag force from the floating part to the fixed part.

Additionally or alternatively, the connection may comprise a guide pin, which may be connected, mounted, fixed or secured to one of the floating and fixed parts and/or slidably connected to, e.g. slidable within a bore in, the other of the floating and fixed parts. The guide pin may be slidable within a resilient damping sleeve disposed within the bore.

The drag force transmission pin may be longer and/or larger than the guide pin. The or each pin may be connected, mounted, fixed or secured to the fixed part. Additionally or alternatively, the or each bore may be in, e.g. comprised or incorporated in, the floating part.

The drag force transmission pin may be in a trailing position, e.g. in relation to the forward rotation of a brake disc to be received, in use, between the limbs. The guide pin may be in a leading position, e.g. in relation to the forward rotation of a brake disc to be received, in use, between the limbs. Alternatively, the or a further drag force transmission pin may be in a leading position, e.g. in relation to the forward rotation of a brake disc to be received, in use, between the limbs. The forward rotation of the brake disc may comprise rotation in a direction when the vehicle moves, in use, in a forward direction.

The floating part may comprise first and second floating members, which may be connected or secured, e.g. releasably connected or secured, together or to one another. The first floating member may include the first limb and/or one or more, e.g. a pair of, guide portions. The guide portion(s) may be formed integrally with the first limb. Each guide portion may comprise a bore for receiving a respective pin, e.g. a respective one of the drag force transmission pin and guide pin. The pins may slidably connect the floating part to the fixed part. The second floating member may include the second limb and/or the one or more bridging portions. The one or more bridging portions may be formed integrally with the second limb.

The first floating member may be formed of a different material than the second floating member. The materials and/or forming processes may be selected to suit the particular application. For example, the second floating member may be formed of a stronger material than the first floating member and/or the first floating member may be formed of a weaker material than the second floating member. The reverse is also envisaged. In embodiments, one of the floating members may be cast, while the other may be machined from a billet.

The actuation means may comprise one or more cylinders, which may be comprised, incorporated or formed in the first limb. The actuation means may comprise one or more pistons, each of which may be received in a respective one of the cylinders. The or each piston may be reciprocable toward a rotating brake disc to apply the brake force. The actuation means may comprise one or more channels for supplying and/or evacuating a hydraulic fluid to and/or from the cylinder, e.g. in order to cause the piston to reciprocate therein. The one or more channels may be formed in the floating part, e.g. the first floating member.

The brake caliper may comprise reaction-type brake caliper or a pin-slider type brake caliper.

The brake force may comprise a service brake force. The actuation means may comprise a parking brake mechanism, e.g. for applying a brake force such as a parking brake force, for clamping, between the limbs, a pair of brake members against a stationary or substantially stationary brake disc. The parking brake mechanism may comprise a lever, e.g. for manual operation, or a motor, e.g. for automatic or motorised operation.

A more general aspect of the invention provides a brake caliper body comprising a fixed part and a floating part, e.g. movably mounted to the fixed part, including a pair of opposed, spaced limbs, one of the limbs being configured to include actuation means operable to apply a brake force for clamping, between the limbs, a pair of brake members against a rotating brake disc; wherein the caliper is configured such that, on application, in use, of the brake force, rotation of the brake disc exerts a drag force on the brake members, which causes the brake members to brace against a bracing abutment of one or both of the fixed and/or floating parts.

Another aspect of the invention provides a braking apparatus comprising a brake caliper, e.g. a brake caliper as described above, and a pair of opposed braking members, which may be movably received between the first and second limbs of the brake caliper.

The braking apparatus may comprise a brake disc disposed between the braking members.

Another aspect of the invention provides a vehicle comprising a brake caliper or braking apparatus, e.g. as described above.

Another aspect of the invention provides a method of making a brake caliper, for example as described above.

Yet another aspect of the invention provides a method of slowing a vehicle comprising operating an actuation means associated with a first limb of a floating part of a brake caliper to cause a first brake member to contact a first side of a rotating brake disc, thereby drawing a second limb of the floating part toward the first limb to cause a second brake member to contact a second side of the rotating brake disc and clamping the rotating brake disc between the brake members such that the brake disc exerts a drag force on the brake members, which causes at least one of the brake members to brace against a bracing abutment of the floating part.

For the avoidance of doubt, any of the features described herein apply equally to any aspect of the invention. For example, the brake caliper or braking apparatus or vehicle may comprise any one or more features of the method relevant thereto and/or the method may comprise any one or more features or steps relevant to one or more features of the brake caliper or braking apparatus of vehicle.

Another aspect of the invention provides a computer program element comprising and/or describing and/or defining a three-dimensional design for use with a simulation means or a three-dimensional additive or subtractive manufacturing means or device, e.g. a threedimensional printer or CNC machine, the three-dimensional design comprising an embodiment of one or more components of the brake caliper described above.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. For the avoidance of doubt, the terms “may”, “and/or”, “e.g.”, “for example” and any similar term as used herein should be interpreted as non-limiting such that any feature so-described need not be present. Indeed, any combination of optional features is expressly envisaged without departing from the scope of the invention, whether or not these are expressly claimed. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

Figure 1 is a top view of a brake caliper according to an embodiment of the invention;

Figure 2 is a partial section view through the line X-X in Figure 1;

Figure 3 is a rear view of the brake caliper of Figures 1 and 2;

Figure 4 is a section view through the line Y-Y of Figure 3;

Figure 5 is a section view through the line Z-Z in Figure 3;

Figure 6 is a schematic view of a vehicle with a braking system including four brake calipers according to an embodiment of the invention;

Figure 7 is a perspective view of a brake caliper according to another embodiment of the invention from above;

Figure 8 is a top view of the brake caliper of Figure 7;

Figure 9 is a perspective view of the brake caliper of Figures 7 and 8 from below;

Figure 10 is a side view of the brake caliper of Figures 7 to 9 from the mounting side;

Figure 11 is a perspective view of the second floating member of the brake caliper of Figures 7 to 10; and

Figure 12 is a perspective view of the fixed part of the brake caliper of Figures 7 to 10.

Referring now to Figures 1 to 5, there is shown a brake caliper 1 according to an embodiment of the invention, which is operable to apply a service braking force to slow a vehicle 10, as illustrated in Figure 6. In this embodiment, the caliper 1 includes a fixed part 2 for attachment to the vehicle 10 and a floating part 3 movably mounted to the fixed part 2 by a pair of slider pins 4, 5.

The vehicle 10 includes a braking system 11 including an actuator 12, a brake pedal and master cylinder in this embodiment, which feeds each of a plurality of calipers 1 via brake lines 13. Each wheel 14 of the vehicle 10 includes a brake disc 15 coupled thereto and for rotation therewith. As is per se conventional, the caliper 1 receives a pair of brake members 6a, 6b for applying a braking force to the brake disc 15, thereby to slow the vehicle 10. The brake members 6a, 6b each include a carrier plate 61a, 61b having disposed thereon a friction material 62a, 62b which engages the brake disc 15 to create a frictional force to slow the brake disc 15 and thereby slow the vehicle 10.

In this embodiment, the fixed part 2 of the caliper 1 is in the form of a generally U-shaped plate with a pair of bracing arms 20, 21 projecting upwardly from a mounting base 22. The mounting base 22 includes a pair of spaced mounting holes 23 through its thickness for securing the caliper 1 to the vehicle 10. Each bracing arm 20, 21 includes a threaded guide pin mounting hole 24, 25 for threadedly engaging a respective one of the slider pins 4, 5.

A first of the pins 4, 5, in this embodiment a drag force transmission pin 4, threadedly engages a first guide pin mounting hole 24 such that the pin 4 projects orthogonally with respect to the fixed part 2. A second of the pins 4, 5, in this embodiment a guide pin 5, engages a second guide pin mounting hole 25 such that the pin 5 projects orthogonally with respect to the fixed part 2. A first brake member 6a is received between the bracing arms 20, 21 such that lateral sides 63a, 64a of the carrier plate 61a lie adjacent an inner, lateral surface 20a, 21a of a respective one of the bracing arms 20, 21.

The floating part 3 in this embodiment includes a pair of opposed, spaced limbs 30, 31 connected together by a pair of bridging portions 32. A first limb 30 includes a pair of guide portions 40, 50 formed integrally with a central portion 33, thereby providing a unitary first floating member 3a. The first guide portion 40 includes a blind bore 41 within which is slidably received the drag force transmission pin 4. The second guide portion 50 includes a through bore 51 within which is received a resilient sleeve 52 having a blind bore 53 therein. The guide pin 5 is slidably received in the blind bore 53 of the resilient sleeve 52.

The central portion 33 includes an actuation means in the form of a central blind bore providing a cylinder 33a within which a piston 33b is slidably received. The central portion 33 also includes a seal ring 33c within the cylinder 33a for sealingly engaging with the piston 33b and an inlet port 33d for feeding a hydraulic fluid into the cylinder 33a to cause the piston 33b to reciprocate therein.

A second limb 31 of the floating part 3 includes a recess 34 within which the carrier plate 61b of a second brake member 6b is received. The recess 34 includes opposed lateral surfaces 34a, 34b along which lateral sides 63b, 64b of the carrier plate 61b of the second brake member 6b lie. The second limb 31 is also profiled such that an actuating plate 31a is provided which engages the exposed major surface of the carrier plate 61b and a reinforcement rib 31b extending along the actuating plate 31a and perpendicular thereto. The bridging portions 32 extend from each end of the second limb 31 and are formed integrally therewith, thereby providing a unitary second floating member 3b. The second floating member 3b may advantageously be formed of a stronger material than the first floating member 3a. The opposite is also envisaged.

The reinforcement rib 31b extends from one of the bridging portions 32 to the other on an outboard side of the actuating plate 31a. Each bridging portion 32 also includes an inner reinforcing web 32a which defines, in this embodiment, the recess 34 and lateral surfaces 34a, 34b, which is formed on an inboard side of the actuating plate 31a.

In this embodiment and as shown more clearly in Figure 2, the bridging portions 32 are curved to follow substantially the curve of a brake disc 15. The second floating member 3b is substantially U-shaped in plan and each bridging portion 32 includes a threaded bore (not shown) adjacent its free end. The first floating member 3a includes a pair of holes (not shown) which receive threaded fasteners 35 extending therethrough and threadedly engaging the threaded bores (not shown) of the bridging portions 32 to secure the first and second floating members 3a, 3b together.

With the slider pins 4, 5 secured to fixed part 2 and slidably mounted to the floating part 3, the first limb 30 is located on an outboard side of the first brake member 6a and the second limb 31 is located on an outboard side of the second brake member 6b. In the assembled configuration, the cylinder 33a and piston 33b face the carrier plate 61a of the first brake member 6a and the recess 34 of the second limb 31 receives the carrier plate 61b of the second brake member 6b.

The floating part 3 also includes a pair of retaining pins 36 each of which spans a respective side of the brake members 6a, 6b and maintain a spring retainer 37 against the brake members 6a, 6b to retain them in position. The retaining pins 36 and spring retainer 37 may be removed to access the brake members 6a, 6b.

In use, a braking input received, in use, by the actuator 12 creates a hydraulic pressure within the brake lines 13, which are fluidly coupled to the inlet port 33d, thereby causing the piston 33b to move toward the first brake member 6a. This urges the first brake member 6a against a first side of the brake disc 15, thereby drawing the second limb 31 toward the brake disc 15.

As a result, the second limb 31 draws the second brake member 6b into contact with the second side of the brake disc 15 and further movement of the piston 33b causes the brake disc 15 to be clamped between the brake members 6a, 6b, thereby exerting a braking force on the brake disc 15 in a direction perpendicular thereto, or parallel to its axis of rotation.

It will be appreciated that rotation of the brake disc 15 exerts a drag force on the brake members 6a, 6b, which is perpendicular to the direction of the brake force. Depending on the direction of movement of the vehicle 10, and the corresponding direction of rotation of the brake disc 15, one of the lateral sides lateral sides 63a, 64a of the carrier plate 61a of the first brake member 6a will brace against one of the adjacent inner, lateral surface 20a, 21a of the bracing arms 20, 21. Similarly, one of the lateral sides 63b, 64b of the carrier plate 61b of the second brake member 6b will brace against one of the adjacent lateral surfaces 34a, 34b of the recess 34 associated with the second limb 31 of the floating part 3.

As such, part of the drag force created during braking is transmitted from the second brake member 6b through to the floating part 3 and to the fixed part 2 via the slider pins 4, 5. It will be appreciated that the presence of the resilient sleeve 52 causes the majority of this drag force transmission to take place through the drag force transmission pin 4.

In this embodiment, when the vehicle 10 travels in a forward direction the guide pin 5 is in a leading position and the drag force transmission pin 4 is in a trailing position. As such, the second lateral side 64b of the carrier plate 61b of the second brake member 6b braces against the lateral surface 34b of the recess 34 nearest the drag force transmission pin 4. It will be appreciated that this configuration is preferable as the speed of travel will invariably be greater when the vehicle 10 travels in this direction and so the majority of the forces will be transmitted to the fixed part 2 via the drag force transmission pin 4 and not through the guide pin 5.

As a result of the above configuration, the construction of the fixed part 2 may be simplified, with the requirement for strength and robustness being transferred to the drag force transmission pin 4 and its slidable connection. This has proven to be beneficial in some applications where the space available to accommodate the fixed part 2 is restricted. The aforementioned caliper 1 is also beneficial as it enables access to the brake members 6a, 6b by simply removing the retaining pins 36 and spring retainer 37.

Turning now to Figures 7 to 12, there is shown a brake caliper 100 according to another embodiment of the invention, wherein like references are labelled with like reference numbers. Whilst the specific shape of the features of the brake caliper 100 shown in this embodiment vary somewhat from those of the embodiment described above, they are broadly similar and as such these will not be described further herein.

The brake caliper 100 according to this embodiment differs mainly in that the actuation means includes a parking brake mechanism 107 in addition to cylinder 33a and piston 33b io arrangement. As with the caliper 1 according to the earlier embodiment, the cylinder 33a and piston 33b arrangement are configured to apply a service brake force. However, in this embodiment, the parking brake mechanism 107 is configured to apply a parking brake force for clamping the brake members 6a, 6b against a stationary or substantially stationary brake disc 15.

The parking brake mechanism 107 includes a cable mounting arm 170 with an aperture 171 for receiving a parking brake cable (not shown) and to which the sheath thereof is secured. The parking brake mechanism 107 also includes a lever 172 pivotally mounted relative to the mounting arm 170 and operatively connected to a mechanism (not shown) within the first limb 30. The free end of the lever 172 includes a hook 173 for receiving the free end of the parking brake cable (not shown). In use, a parking brake actuator (not shown) within the vehicle is operated to retract the parking brake cable (not shown) within its sheath, thereby actuating the lever 172 and operating the mechanism (not shown) to apply a parking brake force to the brake disc 15.

It will be appreciated by those skilled in the art that several variations are envisaged without departing from the scope of the invention. For example, it may be beneficial in some embodiments for both bracing abutments to be included in or on the floating part 3. Additionally or alternatively, the position of the pins 4, 5 may be reversed in certain applications, for example where the configuration of the floating part 3 is such that the forces are distributed differently. Alternatively, the caliper 1 may be configured with two drag force transmission pins 4. Moreover, the parking brake mechanism 107 may be automatic, motorised or omitted.

It will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features and/or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.

Claims

1. A brake caliper comprising:

a fixed part for attachment to a vehicle; and

5 a floating part movably mounted to the fixed part and including a pair of opposed, spaced limbs and a bracing abutment, one of the limbs comprising actuation means operable to apply a brake force for clamping, between the limbs, a pair of brake members against a rotating brake disc;

wherein the caliper is configured such that, on application, in use, of the brake io force, rotation of the brake disc exerts a drag force on the brake members, which causes at least one of the brake members to brace against the bracing abutment of the floating part.

2. Brake caliper according to claim 1, wherein the fixed part comprises a first bracing

15 abutment and the bracing abutment of the floating part comprises a second bracing abutment, wherein the caliper is configured such that, on application, in use, of the brake force, rotation of the brake disc exerts a drag force on the brake members, which causes a first of the brake members to brace against the first bracing abutment and causes a second of the brake members to brace against the second bracing

20 abutment.

3. Brake caliper according to claim 2, wherein the fixed part comprises a pair of first bracing abutments between which the first brake member is receivable and the floating part comprises a pair of second bracing abutments between which the second

25 brake member is receivable such that the first and second brake members each brace, in use, against a respective one of the bracing abutments when the brake disc rotates in a first direction and against a respective other of the bracing abutments when the brake disc rotates in a second direction opposite the first direction.

30

4. Brake caliper according to any preceding claim, wherein the fixed part and floating part are slidably connected such that at least part of the drag force exerted, in use, on the at least one brake member is transmitted from the floating part to the fixed part via the slidable connection.

5. Brake caliper according to claim 4, wherein the slidable connection comprises a drag force transmission pin substantially orthogonal to the limbs, the drag force transmission pin being secured to one of the floating and fixed parts and slidable within a bore in the other of the floating and fixed parts for transmitting at least part of the drag force from the floating part to the fixed part.

6. Brake caliper according to claim 4 or claim 5, wherein the slidable connection comprises a guide pin secured to one of the floating and fixed parts and slidable within a bore in the other of the floating and fixed parts.

7. Brake caliper according to claim 6, wherein the guide pin is slidable within a resilient damping sleeve disposed within the bore.

8. Brake caliper according to claim 6 or claim 7 when dependent upon claim 5, wherein the drag force transmission pin is longer and/or larger than the guide pin.

9. Brake caliper according to any one of claims 5 to 8, wherein the or each pin is secured to the fixed part and the or each bore is in the floating part.

10. Brake caliper according to any one of claims 5 to 9, wherein the drag force transmission pin is in a trailing position.

11. Brake caliper according to any preceding claim comprising one or more bridging portions connecting the limbs.

12. Brake caliper according to claim 11, wherein the limb with the actuation means comprises a first limb and the other limb comprises a second limb, the bridging portion(s) and/or the second limb comprising the bracing abutment(s) of the floating part.

13. Brake caliper according to claim 11 or claim 12, wherein the floating part comprises a first floating member including the limb with the actuation means and a second floating member releasably secured to the first floating member and including the other limb and the one or more bridging portions.

14. Brake caliper according to claim 13, wherein the limb with the actuation means comprises a first limb and the other limb comprises a second limb, the first floating member comprising a pair of guide portions formed integrally with the first limb, each guide portion comprising a bore for receiving a respective pin slidably connecting the

5 floating part to the fixed part.

15. Brake caliper according to claim 13 or claim 14, wherein the second limb and the one or more bridging portions of the second floating member are formed integrally.

io

16. Brake caliper according to any one of claims 13 to 15, wherein the first floating member is formed of a different material than the second floating member.

17. Brake caliper according to claim 16, wherein the second floating member is formed of a stronger material than the first floating member.

18. Brake caliper according to any preceding claim, wherein the actuation means comprises a cylinder formed in the limb within which a piston is reciprocable toward the rotating brake disc to apply the brake force.

20 19. Brake caliper according to claim 18, wherein the brake force comprises a service brake force and the actuation means comprises a parking brake mechanism for applying a parking brake force for clamping, between the limbs, a pair of brake members against a stationary brake disc.

25 20. Brake caliper according to any preceding claim, wherein the limb with the actuation means comprises a first limb and the other limb comprises a second limb, the caliper comprising a pair of bridging members each connecting one of the ends of the second limb to the first limb, wherein the second limb comprises a reinforcement rib extending between the bridging members.

21. A braking apparatus comprising the brake caliper of any preceding claim and a pair of opposed braking members movabiy received between the limbs of the brake caliper.

22. A braking apparatus according to claim 21 comprising a brake disc disposed between the braking members.

23. A vehicle comprising the brake caliper according to any one of claims 1 to 20 or a

5 braking apparatus according to claim 21 or claim 22.

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