WO2016154007A1

WO2016154007A1 - Alternative approaches to mounting the s-cam tube of a vehicle brake assembly

Info

Publication number: WO2016154007A1
Application number: PCT/US2016/023154
Authority: WO
Inventors: Damon E. DILWORTH; Matthew J. VAN METER; Michael P. BLOINK; Jennifer Y. WU; Ashley T. Dudding
Original assignee: Hendrickson Usa, L.L.C.
Priority date: 2015-03-20
Filing date: 2016-03-18
Publication date: 2016-09-29

Abstract

A variety of approaches are provided for securing the support tube of an S- cam camshaft to a brake spider of a vehicle steering assembly. The support tube may be secured to the brake spider in an axial direction or a non-axial (e.g., radial) direction. According to an axial connection approach, a locking feature is provided to prevent rotation of the support tube with respect to the brake spider. According to non-axial approaches, the support tube may be secured to the brake spider via an attachment extension or attachment cap or attachment collar, which may be secured to the brake spider by a radially oriented mechanical fastener.

Description

ALTERNATIVE APPROACHES TO MOUNTING THE S-CAM TUBE OF A

VEHICLE BRAKE ASSEMBLY

RELATED APPLICATIONS

This application claims the benefit of and priority of U.S. Provisional Patent Application Serial No. 62/136,040, filed March 20, 2015, the contents of which are incorporated by reference herein.

DESCRIPTION

TECHNICAL FIELD

The present subject matter relates to brake assemblies for wheeled vehicles. More particularly, the present subject matter relates to the mounting of the S-cam support tube of a vehicle brake assembly.

BACKGROUND

In conventional heavy-duty vehicle brake systems, an S-cam is rotated to press brake shoes against a brake drum to decelerate a vehicle. The S-cam is connected to a camshaft, which is typically supported at each of its ends by a bushing or bearing. These bushings usually are greased to reduce friction between the bushings and the camshaft as the camshaft and S-cam are rotated. If the bushings or the camshaft become worn and/or rotational friction of the camshaft against the bushings increases, the overall efficiency of the brake system decreases. When bushing or camshaft wear exceeds predetermined limits, bushing and/or camshaft replacement is required.

A vehicle brake assembly A according to conventional design is illustrated in Figs. 1 and 1 A. The vehicle brake assembly A includes a camshaft support tube T (Fig. 2) in which a camshaft M (Fig. 1 A) connected to an S-cam C is positioned for rotation within the camshaft support tube T. The camshaft support tube T extends through an axially oriented bore of a brake spider K, with a plate P affixed to the camshaft support tube T being fixedly secured to the brake spider K by one or more axially oriented mechanical fasteners F. As used herein, the term "axially" (and variations thereof) is used to refer to a direction at least substantially parallel to the central axis of a spindle S associated with the brake spider K. In contrast, the term "non-axially" (and variations thereof) refers to a direction that is not at least substantially parallel to the central axis of the spindle S, while the term "radially" (and variations thereof) refers to a direction residing in a plane that is at least substantially perpendicular to the central axis of the spindle S, which may include a direction that intersects and is substantially perpendicular to the central axis of the spindle S. Accordingly, it can be said that the camshaft support tube T of Figs. 1 and 1 A is secured to the brake spider K in an axial direction because axially oriented mechanical fasteners F are used to connect the camshaft support tube T to the brake spider K with an axially facing surface of the camshaft support tube T (in particular, a surface of the plate P) in contact with an axially facing surface of the brake spider K. Other known vehicle brake assemblies include the one described in U.S. Patent No. 6,240,806, which is hereby incorporated herein by reference.

SUMMARY

There are several aspects of the present subject matter which may be embodied separately or together in the devices and systems described and claimed below. These aspects may be employed alone or in combination with other aspects of the subject matter described herein, and the description of these aspects together is not intended to preclude the use of these aspects separately or the claiming of such aspects separately or in different combinations as set forth in the claims appended hereto.

In one aspect, a vehicle brake assembly comprises a brake spider, an S- cam camshaft, and a camshaft support tube. The camshaft support tube receives at least a portion of the S-cam camshaft and is fixedly secured to the brake spider in a non-axial direction.

In another aspect, a vehicle brake assembly comprises a brake spider, an S-cam camshaft, and a camshaft support tube. The brake spider defines an axially oriented bore and includes an axial face with a locking formation. The camshaft support tube is positioned within the axially oriented bore of the brake spider and receives at least a portion of the S-cam camshaft. The camshaft support tube includes a locking projection, which cooperates with the locking formation to prevent rotation of the camshaft support tube with respect to the brake spider.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a front perspective view of selected components of a vehicle brake assembly according to known design;

Fig. 1 A is an exploded view of the vehicle brake assembly of Fig. 1 ;

Fig. 2 is a side perspective view of a camshaft support tube of the vehicle brake assembly of Fig. 1 ;

Fig. 3 is a top plan view of selected components of a vehicle brake assembly, with a camshaft support tube being secured to a brake spider by an axial approach according to an aspect of the present disclosure;

Fig. 4 is a rear perspective view of the vehicle brake assembly of Fig. 3; Fig. 5 is an exploded view of the vehicle brake assembly of Fig. 3;

Fig. 6 is a front elevational view of selected components of a vehicle brake assembly, with a camshaft support tube being secured to a brake spider by a non- axial approach according to an aspect of the present disclosure;

Fig. 7 is a rear perspective view of the vehicle brake assembly of Fig. 6; Fig. 8 is a rear perspective view of the brake spider of the vehicle brake assembly of Fig. 6;

Fig. 9 is a front perspective view of an alternative camshaft support tube incorporated into the vehicle brake assembly of Fig. 6;

Fig. 10 is a front perspective view of the vehicle brake assembly of Fig. 6, incorporating the camshaft support tube of Fig. 9;

Fig. 1 1 is a rear perspective view of selected components of a vehicle brake assembly, with a camshaft support tube being secured to a brake spider by another non-axial approach according to an aspect of the present disclosure;

Fig. 12 is an exploded view of the vehicle brake assembly of Fig. 1 1 ;

Fig. 13 is a front perspective view of the brake spider and an attachment cap of the vehicle brake assembly of Figs. 1 1 and 1 2;

Fig. 14 is a front perspective view of selected components of a vehicle brake assembly, with a camshaft support tube being secured to a brake spider by another non-axial approach according to an aspect of the present disclosure; Fig. 15 is a front perspective view of the brake spider of the vehicle brake assembly of Fig. 14;

Fig. 16 is a top perspective view of selected components of a vehicle brake assembly, with a camshaft support tube being secured to a brake spider by another non-axial approach according to an aspect of the present disclosure;

Fig. 17 is a side perspective view of a camshaft support tube of the vehicle brake assembly of Fig. 16;

Fig. 18 is a front perspective view of selected components of a vehicle brake assembly, with a camshaft support tube being secured to a brake spider by another non-axial approach according to an aspect of the present disclosure; and

Fig. 19 is a rear perspective view of the vehicle brake assembly of Fig. 1 8.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The embodiments disclosed herein are for the purpose of providing a description of the present subject matter, and it is understood that the subject matter may be embodied in various other forms and combinations not shown in detail. Therefore, specific embodiments and features disclosed herein are not to be interpreted as limiting the subject matter as defined in the accompanying claims.

Figs. 3-5 show selected components of a vehicle brake assembly 10 incorporating aspects of the present disclosure. The vehicle brake assembly 10 includes a steering knuckle 12 having a vertical portion 14. In the illustrated embodiment, the vertical portion 14 of the steering knuckle 12 is configured as a brake spider and may be referred to herein as a brake spider, but it should be understood that steering knuckles according to the present disclosure may be provided with an integrated brake spider (as illustrated) or with a brake spider that is separately provided and secured to the steering knuckle (e.g., to the vertical portion of the steering knuckle).

The illustrated steering knuckle 12 is comprised of two pieces or elements or members 16 and 18, which are secured together (e.g., by mechanical fasteners). The first piece 16 may be referred to herein as the knuckle body or backbone and includes the brake spider 14, while the second piece 18 may be referred to as the upper yolk arm. While the illustrated steering knuckle 12 is comprised of two pieces, it is within the scope of the present disclosure for the steering knuckle to be formed as a single piece or to be formed of three or more components. In a preferred embodiment, steering knuckles according to the present disclosure are provided in accordance with the description of U.S.

Provisional Patent Application Serial No. 62/136,308, entitled "Steering Knuckle With Integrated Brake Mounting Provision," which is incorporated herein by reference, but it is also within the scope of the present disclosure for the steering knuckle to have a different configuration.

The brake spider 14 includes a plurality of axially oriented bores, one of which receives a spindle 20, another of which (identified in Fig. 5 as 22) receives a camshaft support tube 24, and the rest of which may receive mechanical fasteners (e.g., bolts) that secure components of the vehicle brake assembly 10 or of a vehicle steering assembly to the brake spider 14. One or more of the axially bores may be configured to receive an anchor pin for associating brake shoes of the vehicle brake assembly 10 to the brake spider 14.

The camshaft support tube 24 extends between first and second ends 26 and 28 (Fig. 5), with a wing bracket or lever 30 affixed at or adjacent to the second end 30. The wing bracket 30 is also secured to a brake chamber 32, which has a pushrod (not visible) pivotally connected to an upper end of a slack adjuster 34. The lower end of the slack adjuster 34 includes a splined bore 36, which receives a splined section or end 38 of an S-cam camshaft 40 (Fig. 5). The S-cam camshaft 40 is received within the camshaft support tube 24, with the splined section 38 of the S-cam camshaft 40 positioned outside of the camshaft support tube 24 (where the splined section 38 is received by the splined bore 36 of the slack adjuster 34). The other end of the S-cam camshaft 40 includes an associated S-cam 42, which is also positioned outside of the camshaft support tube 24, adjacent to the brake spider 14. The camshaft support tube 24 may also receive a plurality of bushings or bearings associated with the S-cam camshaft 40 to allow the S-cam camshaft 40 to rotate about its axially oriented central axis within the camshaft support tube 24.

In use, a driver applies pressure to a brake pedal, which causes the brake chamber 32 to move the pushrod. The pushrod moves the upper end of the slack adjuster 34, which causes the lower end of the slack adjuster 34 to rotate, along with the S-cam camshaft 40. The S-cam 42 at the opposite end of the S-cam camshaft 40 moves brake shoes (not illustrated) into contact with the inner surface of a brake drum (not illustrated), thereby slowing the rotation of the brake drum. The brake drum is coupled to a wheel of the vehicle, such that slowing the rotation of the brake drum also slows rotation of the wheel, thereby decreasing the speed of the vehicle.

In contrast to the vehicle brake assembly A of Fig. 1 , the camshaft support tube 24 of Figs. 3-5 is received by the associated axially oriented bore 22 of the brake spider 14 without being secured to the brake spider 14 by axially oriented mechanical fasteners. Instead, the first end 26 of the camshaft support tube 24 is configured to cooperate with a mechanical fastener 44 to trap the brake spider 14 between the mechanical fastener 44 and a locking projection 46 affixed to the camshaft support tube 24 when the camshaft support tube 24 is received within the axially oriented bore 22. In one embodiment, the first end 26 of the camshaft support tube 24 is externally threaded, with the mechanical fastener 44 being provided as an internally threaded hexagonal nut that receives the threaded end 26 of the camshaft support tube 24. In other embodiments, the first end 26 of the camshaft support tube 24 may be differently configured to cooperate with a differently configured mechanical fastener. Preferably, the mechanical fastener 44 is removably associated with the camshaft support tube 24 (e.g., by a threaded connection) to allow for the vehicle brake assembly 10 to be disassembled for servicing, but it is also within the scope of the present disclosure for the

mechanical fastener 44 to be fixedly secured to the camshaft support tube 24 during assembly of the vehicle brake assembly 1 0.

By omitting the axially oriented mechanical fasteners F of Fig. 2, other means are provided for preventing rotation of the camshaft support tube 24 with respect to the brake spider 14. In the illustrated embodiment, one of the axial faces 48 of the brake spider 14 (the one facing away from the spindle 20 and toward the brake chamber 32 in Figs. 3-5) is provided with a locking formation 50, which cooperates with the locking projection 46 to prevent rotation of the camshaft support tube 24 with respect to the brake spider 14.

The locking projection and formation 46 and 50 may be variously configured to prevent relative rotation of the camshaft support tube 24 and brake spider 14, but in one embodiment, the locking projection 50 is provided with a non-circular outer surface or perimeter. By such an arrangement, the locking formation 50 may present an obstacle to the rotation of the locking projection 46 (and, hence, the camshaft support tube 24 to which the locking projection 46 is affixed). In the illustrated embodiment, the locking projection 46 has a hexagonal shape, with the locking formation 50 comprising at least one projection from the axial face 48 of the brake spider 14. The locking formation 50 may be generally linear or flat and oriented parallel and directly adjacent to one of the flat radial surfaces of the hexagonal locking projection 46. Positioning similarly shaped (flat, in the illustrated embodiment) surfaces directly adjacent to each other, any tendency of the camshaft support tube 24 to rotate is prevented by interference of the locking formation 50, which contacts the locking projection 46 to resist and prevent rotation of the locking projection 46 and associated camshaft support tube 24. While a locking formation 50 comprising a single projection may be sufficient to prevent relative rotation, the locking formation 50 may comprise two or more projections (each associated with a different flat radial surface of the locking projection 46) to hold the locking projection 46 in place.

It should be understood that the illustrated configurations of the locking projection and formation 46 and 50 are merely exemplary and that they may be differently configured without departing from the scope of the present disclosure. For example, the locking projection 46 may be provided with a groove or keyway that receives at least a portion (preferably a complementary shaped portion) of the locking formation 50 to prevent rotation of the camshaft support tube 24 with respect to the brake spider 14. Alternatively, the locking formation 50 may be provided with a groove or keyway in which a portion of the locking projection 46 is received to prevent relative rotation. In yet another embodiment, rather than the locking formation 50 comprising a projection, it may be provided as a pocket or cavity that receives at least a portion of the locking projection 46. By providing such a pocket or cavity with a shape that is complementary with respect to at least a portion of the locking projection 46, the complementary surfaces may cooperate to prevent rotation of the camshaft support tube 24, as described above with respect to a locking formation 50 formed as a projection.

Regardless of the particular configurations of the locking projection and formation 46 and 50, it will be seen that trapping the brake spider 14 between the mechanical fastener 44 and locking projection 46 (with the camshaft support tube 24 received within the axial bore 22) prevents axial and radial movement of the camshaft support tube 24 with respect to the brake spider 14, while the locking projection and formation 46 and 50 cooperate to prevent rotation of the camshaft support tube 24, thereby effectively fixedly securing the camshaft support tube 24 to the brake spider 14. This embodiment allows for the omission of radially oriented mechanical fasteners to secure the camshaft support tube to the brake spider and may also reduce the size of the brake spider (because less surface area is needed around the axial bore to accommodate the mechanical fasteners), thereby reducing the total weight of the vehicle brake assembly 1 0 compared to typical vehicle brake assemblies.

Figs. 6 and 7 illustrate components of a vehicle brake assembly 100 exhibiting an alternative approach to fixedly securing a camshaft support tube 102 to a brake spider 104. In the embodiment of Figs. 6 and 7, the camshaft support tube 102 is provided with an integrally formed attachment extension 106. The brake spider 104 (which is shown as being incorporated into the steering knuckle 108, but may be separately provided) is provided with an attachment formation 1 10 with a radially facing surface 1 12, as shown in Fig. 8. The attachment extension 106 also has a radially facing surface 1 14, which has a shape that is complementary to the shape of the radially facing surface 1 12 of the attachment formation 1 10. In the illustrated embodiment, the radially facing surfaces 1 12 and 1 14 are generally V-shaped (having a pair of substantially planar surfaces oriented at an obtuse angle, with an arcuate transition between the planar surfaces), with the attachment extension 106 provided as a wedge that seats within the attachment formation 1 10 of the brake spider 104. Radially facing surfaces 1 12 and 1 14 with different (i.e., non V-shaped) shapes, including matching convex and concave shapes and matching tapered shapes, may also be provided without departing from the scope of the present disclosure.

With the radially facing surfaces 1 12 and 1 14 in contact, a radially oriented mechanical fastener 1 16 is received within aligned radial bores of the attachment extension and formation 106 and 1 10 to fixedly secure the camshaft support tube 102 to the brake spider 104. The bore of the attachment formation 1 10 of the brake spider 104 may be internally threaded to mate with threads of the mechanical fastener 1 16 (which may be provided as a threaded bolt), but other configurations are also possible and within the scope of the present disclosure.

Figs. 6 and 7 show a pair of identical, substantially parallel mechanical fasteners 1 16 securing the camshaft support tube 1 02 to the brake spider 104, with the mechanical fasteners 1 16 positioned at opposite sides of a camshaft- receiving portion of the camshaft support tube 102. In other embodiments, the camshaft support tube 102 may be secured to the brake spider 104 with a single mechanical fastener or more than two mechanical fasteners, which may be similarly configured or differently configured.

The embodiment of Figs. 6-8 reduces the size of the brake spider 104 (compared to a brake spider according to conventional design), effectively replacing a portion of the brake spider 104 with the attachment extension 106. The attachment extension 106 may be formed of a lighter material than the brake spider 104 (e.g., an aluminum material), thereby reducing the total weight of the vehicle brake assembly 1 00 compared to typical vehicle brake assemblies.

It should be understood that the particular configuration of the camshaft support tube 102 of Figs. 6 and 7 is merely exemplary and that the camshaft support tube may be differently configured without departing from the scope of the present disclosure. For example, Fig. 9 shows a camshaft support tube 1 50 that may be used in combination with the steering knuckle 108 of Fig. 8 (as shown in Fig. 10), but is differently configured than the camshaft support tube 102 of Figs. 6 and 7. The camshaft support tube 1 50 of Fig. 9 includes an integrally formed attachment extension 152, which may be substantially identical to the attachment extension 106 of Figs. 6 and 7, with a radially facing surface 154 having a shape that is complementary to the shape of the radially facing surface 1 12 of the brake spider 104. As described previously with regard to the attachment extension 1 06 of Figs. 6 and 7, the illustrated radially facing surfaces 1 12 and 1 54 are generally V-shaped, but may have differently configured complementary shapes without departing from the scope of the present disclosure. Similarly, while the attachment extension 152 is shown with a pair of radial bores that are aligned with radial bores of the attachment formation 1 10 to receive radially oriented mechanical fasteners 1 16 for securing the camshaft support tube 1 50 to the brake spider 104, other means may be provided for securing the two together when the radially facing surfaces 1 1 2 and 154 are in contact.

The camshaft support tube 150 of Figs. 9 and 10 differs principally from the camshaft support tube 102 of Figs. 6 and 7 in that it includes one or more webs or gussets. The illustrated camshaft support tube 150 is provided with three webs 156, 158, and 1 60, but one or more of the webs may be omitted and additional webs may be provided without departing from the scope of the present disclosure. In particular, the camshaft support tube 150 is provided with a pair of radially facing webs 156 and 1 58, with one web 156, 158 associated with each lateral side of a camshaft-receiving portion of the camshaft support tube 150. Each radially facing web 156, 1 58 is associated with the attachment extension 152 of the camshaft support tube 150, with one of the radially facing webs 1 58 transitioning into a wing bracket or lever 1 62 that may be secured to a brake chamber. The third web 1 60 is axially facing and extends between the camshaft-receiving portion of the camshaft support tube 150 and the lever-defining web 158 and may effectively separate or distinguish the wing bracket or lever 162 from the remainder of the associated web 158. Compared to the camshaft support tube 102 of Figs. 6 and 7, the camshaft support tube 150 of Figs. 9 and 10 may include more material, thereby being heavier than the camshaft support tube 102 of Figs. 6 and 7, but is also stronger and may reduce deflection during brake application. Accordingly, a camshaft support tube of the type shown in Figs. 6 and 7 may be advantageous for situations in which weight must be minimized, while a camshaft support tube of the type shown in Figs. 9 and 10 may be advantageous for situations in which strength and deflection during brake application are prioritized over weight minimization.

Figs. 1 1 and 12 illustrate components of a vehicle brake assembly 200 exhibiting another approach to fixedly securing a camshaft support tube 202 to a brake spider 204. In the embodiment of Figs. 1 1 and 12, the brake spider 204 (which is shown as being integrated into a steering knuckle 206, but may be separately provided) combines with an attachment cap 208 to define an axially oriented bore 210 (Fig. 13). In the illustrated embodiment, a radially facing surface 212 of the brake spider 204 defines half of the bore 210, while a radially facing surface 214 of the attachment cap 208 defines the other half of the bore 21 0 when placed into contact with the radially facing surface 212 of the brake spider 204, but it is also within the scope of the present disclosure for one to define more than half of the bore 210 and the other to define the remainder of the bore 210.

To assemble the vehicle brake assembly 200, the camshaft support tube

202 is positioned between the radially facing surfaces 212 and 214 of the brake spider 204 and attachment cap 208 and then the radially facing surfaces 212 and 214 are moved into contact with each other to define the axially oriented bore 210 in which the camshaft support tube 202 is positioned. With the radially facing surfaces 212 and 214 in contact, a radially oriented mechanical fastener 216 is received within aligned radial bores of the brake spider and attachment cap 204 and 208 to connect the camshaft support tube 202 to the brake spider 204. The radial bore of the brake spider 204 may be internally threaded to mate with threads of the mechanical fastener 216 (which may be provided as a threaded bolt), but other configurations are also possible and within the scope of the present disclosure.

Figs. 1 1 and 12 show two pairs of identical, substantially parallel mechanical fasteners 216 securing the attachment cap 208 to the brake spider 204, with the pairs of mechanical fasteners 21 6 positioned at opposite sides of the camshaft support tube 202. In other embodiments, the camshaft support tube 202 may be secured to the brake spider 204 with more or fewer than four mechanical fasteners, which may be similarly configured or differently configured.

Securing the attachment cap 208 to the brake spider 204 prevents radial movement of the camshaft support tube 202, but may not necessarily prevent axial and rotational movement of the camshaft support tube 202 within the bore 21 0. According to one approach to preventing axial and rotational movement of the camshaft support tube 202, at least one of the radial bores opens into the axial bore 210 (illustrated at 218 in Fig. 13). By such a configuration, a mechanical fastener 216 positioned within the radial bore will extend into the axial bore 210. In the illustrated embodiment, all of the radial bores are configured and arranged to open into the axial bore 210, thereby positioning a section of each of the mechanical fasteners 216 within the axial bore 210, but variations of this configuration (e.g., an embodiment in which at least one of the radial bores does not open into the axial bore 21 0) may also be employed without departing from the scope of the present disclosure.

The camshaft support tube 202 preferably fits relatively snugly within the axial bore 210 (i.e., the outer diameter of the camshaft support tube 202 is equal to the diameter of the axial bore 210) to prevent radial movement of the camshaft support tube 202 within the axial bore 210. Accordingly, the cylindrical outer surface of camshaft support tube 202 may be provided with a groove or flattened portion 220 (Fig. 12) to be contacted by or accommodate a mechanical fastener 21 6 protruding into the axial bore 210. By such a configuration, a portion of at least one mechanical fastener 216 is received within an associated groove or flattened portion 220 of the camshaft support tube 202. Preferably, the mechanical fastener 216 fits snugly within (and more preferably in contact with) the groove or flattened portion 220 to prevent axial movement of the camshaft support tube 202 within the axial bore 210.

Such a configuration may be sufficient to additionally prevent rotation of the camshaft support tube 202 within the axial bore 210, but additional steps may be taken to prevent rotation of the camshaft support tube 202 within the axial bore 21 0. According to one embodiment, one or more of the grooves or flattened portions 220 of the camshaft support tube 202 may be threaded to receive and mate with external threads of the associated mechanical fastener 216. Contact between the mating threads of the mechanical fastener 216 and groove or flattened portion 220 prevents rotation of the camshaft support tube 202 about its central axis within the axial bore 210, thereby effectively fixedly securing the camshaft support tube 202 to the brake spider 204.

The embodiment of Figs. 1 1 -1 3 reduces the size of the brake spider 204

(compared to conventional brake spiders), effectively replacing a portion of the brake spider with the attachment cap 208. The attachment cap 208 may be formed of a lighter material than the brake spider 204 (e.g., an aluminum material), thereby reducing the total weight of the vehicle brake assembly 200 compared to typical vehicle brake assemblies.

Fig. 14 illustrates a variation of the vehicle brake assembly 200 of Figs. 1 1 and 12. In the vehicle brake assembly 300 of Fig. 14, the brake spider 302 (which is shown as being integrated into a steering knuckle 304, but may be separately provided) combines with an attachment cap 306 to define an axially oriented bore. Similar to the embodiment of Figs. 1 1 and 12, a radially facing surface 308 of the brake spider 302 (Fig. 15) defines half of the axial bore, while a radially facing surface of the attachment cap 306 defines the other half of the axial bore when placed into contact with the radially facing surface 308 of the brake spider 302, but it is also within the scope of the present disclosure for one to define more than half of the axial bore and the other to define the remainder of the bore. As in the embodiment of Figs. 1 1 and 12, the camshaft support tube 310 is positioned within the axial bore between the brake spider 302 and the attachment cap 306 (which may be held together by one or more mechanical fasteners 31 2) to prevent radial movement of the camshaft support tube 31 0 with respect to the brake spider 302.

In contrast to the embodiment of Figs. 1 1 and 12, the radial bores in which the mechanical fasteners 31 2 are positioned are not open to the axial bore, so other means are provided to prevent axial and rotational movement of the camshaft support tube 31 0. In particular, the attachment cap 306 may be fixedly secured to the camshaft support tube 310, either before or after connecting the attachment cap 306 to the brake spider 302. The attachment cap 306 may be fixedly secured to the camshaft support tube 310 by any suitable approach, which may include a weld. If the attachment cap 306 is to be welded to the camshaft support tube 31 0, a weld may be applied along one or more edges of the attachment cap 306. Alternatively, or additionally, the attachment cap 306 may be provided with a window or opening 314 in which a weld may be placed to fixedly secure the attachment cap 306 to the camshaft support tube 310. By fixedly securing the attachment cap 306 to the camshaft support tube 310, connecting the attachment cap 306 to the brake spider 302 effectively prevents radial movement (due to the preferably snug fit of the camshaft support tube 310 within the axial bore), axial movement (due to the attachment cap 306 being secured to the camshaft support tube 310), and rotational movement (also due to the attachment cap 306 being secured to the camshaft support tube 310) of the camshaft support tube 31 0. Optionally, the radially facing surface 308 may define at least one radially oriented bore 316 that opens into the portion of the axial bore defined by the radially facing surface 308. The radially oriented bore 316 may receive a dowel pin or other insert that protrudes into the axial bore to bear against the camshaft support tube 31 0, further preventing radial movement of the camshaft support tube 31 0. Other vehicle brake assemblies according to the present disclosure may incorporate a similar bore-and-insert arrangement to assist in preventing radial movement of a camshaft support tube.

This embodiment reduces the size of the brake spider 302 compared to conventional brake spiders, effectively replacing a portion of the brake spider 302 with the attachment cap 306. The attachment cap 306 may be formed of a lighter material than the brake spider 302 (e.g., an aluminum material), thereby reducing the total weight of the vehicle brake assembly 300 compared to typical vehicle brake assemblies.

Fig. 16 illustrates a variation of the vehicle brake assembly 300 of Fig. 14 and of the vehicle brake assembly 100 of Figs. 6 and 7. In the vehicle brake assembly 400 of Fig. 16, the brake spider 402 (which is shown as being integrated into a steering knuckle 404, but may be separately provided) has a radially facing surface of the type shown in Fig. 1 5, which defines a portion of an axial bore. The camshaft support tube 406 includes an integrally formed attachment cap or attachment extension 408 (Fig. 17) with a radially facing surface that may be brought into contact with the radially facing surface of the brake spider 402 to press the camshaft support tube 406 against the radially facing surface of the brake spider 402. The vehicle brake assembly 400 of Fig. 16 is similar to the embodiment of Fig. 15 due to the shape of the attachment cap or attachment extension 408, while being similar to the embodiment of Figs. 6 and 7 due to the attachment cap or attachment extension 408 being integrally formed with the camshaft support tube 406.

If the brake spider 402 is configured as shown in Fig. 15, its radially facing surface defines half of the axial bore, but it is also within the scope of the present disclosure for the radially facing surface of the brake spider 402 to define more or less than half of the axial bore. Regardless of the exact shape of the radially facing surface of the brake spider 402 and associated radially facing surface of the attachment cap or attachment extension 408, securing the two together (with one or more mechanical fasteners 41 0, for example) prevents radial movement of the camshaft support tube 406 with respect to the brake spider 402. On account of the attachment cap or extension 408 being integrally formed with the camshaft support tube 406, securing the attachment cap or extension 408 to the radially facing surface of the brake spider 402 will also prevent axial and rotational movement of the camshaft support tube 406 with respect to the brake spider 402.

This embodiment reduces the size of the brake spider 402 compared to conventional brake spiders, effectively replacing a portion of the brake spider 402 with the attachment cap or extension 408. The attachment cap or extension 408 may be formed of a lighter material than the brake spider 402 (e.g., an aluminum material), thereby reducing the total weight of the vehicle brake assembly 400 compared to typical vehicle brake assemblies.

Figs. 18 and 19 illustrate selected components of another embodiment of a vehicle brake assembly 500 exhibiting an alternative approach to fixedly securing a camshaft support tube 502 to a brake spider 504. In the embodiment of Figs. 18 and 19, the brake spider 504 (which is shown as being incorporated into a steering knuckle 506, but may be separately provided) is provided according to the configuration of Fig. 8, with a radially facing surface 508 having a generally V- shaped profile. The radially facing surface 508 of the brake spider 504 is complementary to a radially facing surface 51 0 of an attachment collar 51 2 and is secured thereto by one or more radially oriented mechanical fasteners 514. It should be understood that the illustrated configurations of the radially facing surfaces and the overall configuration of the attachment collar 51 2 are merely exemplary and that the radially facing surfaces and attachment collar 512 may be differently configured without departing from the scope of the present disclosure. To prevent brake hang up and wear of the brake spider 504 when braking forces move brake shoes and rollers of the vehicle brake assembly 500 in an inboard direction, the vehicle brake assembly 500 (and any of the other vehicle brake assemblies according to the present disclosure) may further include a cam washer 51 6 positioned immediately inboard of the S-cam.

The attachment collar 51 2 defines an axial bore, which receives a camshaft support tube 502. Compared to a vehicle brake assembly in which the axial bore is formed entirely by the brake spider (as in Fig. 1 ), using an attachment collar 512 to define the axial bore may reduce the total weight of the vehicle brake assembly 500 because the attachment collar 512 may be formed of a lighter material than the brake spider 504 (e.g., being formed of an aluminum material).

Positioning the camshaft support tube 502 within the axial bore prevents radial movement of the camshaft support tube 502 with respect to the brake spider 504. To prevent rotation and axial movement of the camshaft support tube 502, a radial bore 518 may be defined by the attachment collar 512, with the radial bore 518 extending from an outer surface of the attachment collar 512 to the axial bore. The radial bore 518 receives a movement restriction member 520 (e.g., a set screw or jam bolt) with an end that presses against the outer surface of the portion of the camshaft support tube 502 that is positioned within the axial bore. In one embodiment, the end of the movement restriction member 520 contacts a flat or generally planar radial surface of the camshaft support tube 502 to prevent rotation and axial movement of the camshaft support tube 502 within the axial bore. In other embodiments, the end of the movement restriction member 520 may be moved into a cavity or pocket defined in the outer surface of the camshaft support tube 502 to effectively lock the camshaft support tube 502, thereby preventing rotation and axial movement of the camshaft support tube 502. It is also within the scope of the present disclosure for the movement restriction member 520 to be omitted, with the camshaft support tube 502 being secured to the attachment collar 512 by a press fit to prevent movement of the camshaft support tube 502.

While many components and bores and surfaces of the various vehicle brake assemblies described herein are characterized as being "radial" or "radially oriented," it should be understood that these components and bores and surfaces may be provided in a non-radial, non-axial orientation. For example, a component or bore or surface characterized herein as being "radial" may be oriented at an angle that is generally perpendicular to the central axis of the spindle of the vehicle brake assembly (e.g., at an 80-degree angle) or some other angle, provided that the component or bore or surface has a non-axial orientation.

It will be understood that the embodiments described above are illustrative of some of the applications of the principles of the present subject matter.

Numerous modifications may be made by those skilled in the art without departing from the spirit and scope of the claimed subject matter, including those

combinations of features that are individually disclosed or claimed herein. For these reasons, the scope hereof is not limited to the above description but is as set forth in the following claims, and it is understood that claims may be directed to the features hereof, including as combinations of features that are individually disclosed or claimed herein.

Claims

1 . A vehicle brake assembly, comprising:

a brake spider;

an S-cam camshaft; and

a camshaft support tube receiving at least a portion of the S-cam camshaft, wherein the camshaft support tube is fixedly secured to the brake spider in a non- axial direction.

2. The vehicle brake assembly of claim 1 , wherein

the camshaft support tube includes an integrally formed attachment extension with a radially facing surface having a shape, and

the brake spider includes an attachment formation with a radially facing surface having a shape that is complementary to the shape of the radially facing surface of the attachment extension of the camshaft support tube, and

further comprising a mechanical fastener securing the attachment extension to the attachment formation, with the radially facing surfaces in contact.

3. The vehicle brake assembly of claim 2, wherein the radially facing surfaces are generally V-shaped.

4. The vehicle brake assembly of claim 2, wherein the radially facing surfaces are generally non-V-shaped.

5. The vehicle brake assembly of any of claims 2-4, further comprising a second mechanical fastener securing the attachment extension to the attachment formation, wherein the mechanical fasteners are positioned at opposite sides of the camshaft support tube.

6. The vehicle brake assembly of claim 1 , further comprising

an attachment cap, and

a mechanical fastener securing the attachment cap to the brake spider, with a portion of the camshaft support tube positioned between the attachment cap and the brake spider.

7. The vehicle brake assembly of claim 6, wherein the mechanical fastener is configured to contact the camshaft support tube to fixedly secure the camshaft support tube to the brake spider.

8. The vehicle brake assembly of any of claims 6-7, wherein the mechanical fastener includes threads configured to cooperate with a threaded portion of the camshaft support tube to fixedly secure the camshaft support tube to the brake spider.

9. The vehicle brake assembly of claim 6, wherein the attachment cap is fixedly secured to the camshaft support tube.

10. The vehicle brake assembly of claim 9, wherein the attachment cap is welded to the camshaft support tube.

1 1 . The vehicle brake assembly of claim 1 , further comprising

an attachment collar defining an axial bore in which a portion of the camshaft support tube is received and a radial bore and including a radially facing surface having a shape, with the brake spider including an attachment formation with a radially facing surfacing having a shape that is complementary to the shape of the radially facing surface of the attachment collar,

a mechanical fastener securing the attachment collar to the attachment formation, with the radially facing surfaces in contact, and

a movement restriction member at least partially received within the radial bore of the attachment collar, with an end of the movement restriction member in contact with the portion of the camshaft support tube received within the axial bore.

12. The vehicle brake assembly of claim 1 1 , wherein the end of the movement restriction member is in contact with a generally planar radial surface of the portion of the camshaft support tube received within the axial bore.

13. A vehicle brake assembly, comprising:

a brake spider defining an axially oriented bore and including an axial face with a locking formation;

an S-cam camshaft; and

a camshaft support tube positioned within the axially oriented bore of the brake spider, receiving at least a portion of the S-cam camshaft, and including a locking projection, wherein the locking projection cooperates with the locking formation to prevent rotation of the camshaft support tube with respect to the brake spider.

14. The vehicle brake assembly of claim 13, wherein the locking projection has a hexagonal shape.

15. The vehicle brake assembly of any of claims 13-14, wherein the locking formation comprises a projection from the axial face of the brake spider.