Patent Description:
The present invention relates to the art of brake component mounting for vehicles. More particularly, the invention relates to a clamp assembly for a mechanical leaf spring axle/suspension system of a heavy duty vehicle.

Heavy-duty vehicles that transport freight, for example, tractor-trailers or semi-trailers and straight trucks, include suspension assemblies that connect the axles of the vehicle to the frame of the vehicle. In some heavy-duty vehicles, the suspension assemblies are connected directly to the primary frame of the vehicle. In other heavy-duty vehicles, the primary frame of the vehicle supports a subframe, and the suspension assemblies connect directly to the subframe. For those heavy-duty vehicles that support a subframe, the subframe can be non-movable or movable, the latter being commonly referred to as a slider box, slider subframe, slider undercarriage, or secondary slider frame. For the purpose of convenience, reference herein will be made to a subframe, with the understanding that such reference is by way of example, and that the present invention applies to heavy-duty vehicle primary frames, movable subframes and non-movable subframes.

In the heavy-duty vehicle art, reference is often made to an axle/suspension system, which typically includes a pair of transversely-spaced suspension assemblies and the axle that the suspension assemblies connect to the vehicle subframe. The axle/suspension system of a heavy-duty vehicle acts to locate or fix the position of the axle and to stabilize the vehicle. More particularly, as the vehicle is traveling over-the-road, its wheels encounter road conditions that impart various forces to the axle on which the wheels are mounted, and in tum, to the suspension assemblies which are connected to and support the axle. These forces consequently act to place or create loads on the axle and the suspension assemblies. In order to minimize the detrimental effect of these forces and resulting loads on the vehicle subframe and other vehicle components as the vehicle is operating, and in tum on any cargo and/or occupants being carried by the vehicle, the axle/suspension system is designed to absorb or dampen at least some of the forces and/or resulting loads.

Two common types of heavy-duty vehicles are known in the art as dry freight vans and refrigerated vans. Dry freight vans include enclosed trailers to keep their freight dry, and are used to transport a wide variety of non-perishable consumer and industrial goods. Refrigerated vans include enclosed trailers with refrigeration systems, and typically are used to transport perishable goods. Such dry freight vans and refrigerated vans have traditionally employed axle/suspension systems that utilize mechanical spring axle/suspension assemblies. These mechanical spring axle/suspension assemblies typically include a pair of leaf spring sets or stacks that are transversely spaced and are connected to the axle. Each leaf spring stack is engineered to carry the rated vertical load of its respective axle. Ordinarily, a trailer of a dry freight or refrigerated van employs two mechanical spring axle/suspension systems at the rear of the trailer, that is, a front axle/suspension system and a rear axle/suspension system, which is a configuration that is collectively referred to in the art as a trailer tandem axle/suspension system. As is known to those skilled in the art, the front end of the trailer is supported by a separate axle/suspension system of the tractor. For the purpose of convenience, reference herein shall be made to a spring axle/suspension system with the understanding that such reference is to a trailer tandem mechanical spring axle/suspension system.

In most axle/suspension systems, it is necessary to mount components of the vehicle braking system to one or more locations on the axle/suspension system. More particularly, the axle of the axle/suspension system includes a central tube, and an axle spindle is integrally connected by any suitable means, such as welding, to each end of the central tube. A wheel end assembly is rotatably mounted, as known in the art, on each axle spindle. A brake drum is mounted on the wheel end assembly, and as will be described in greater detail below, components of the vehicle braking system are actuated to apply friction to the brake drum in order to slow or stop the vehicle. Inasmuch as each end of the axle and its associated spindle, wheel end assembly and brake drum is generally identical to the other, only one axle end and its associated spindle, wheel end assembly and brake drum will be described herein.

As known in the art, when the operator of a heavy-duty vehicle applies the vehicle brakes to slow or stop the vehicle, compressed air is communicated from an air supply source, such as a compressor and/or air tank, through air lines to a brake chamber. The brake chamber converts the air pressure into mechanical force and moves a pushrod. The pushrod in turn moves a slack adjuster, which is connected to one end of a cam shaft of a cam shaft assembly. The cam shaft assembly enables smooth, stable rotation of the cam shaft upon movement of the slack adjuster. An S-cam is mounted on the end of the cam shaft that is opposite the slack adjuster, so that rotation or turning of the cam shaft by the slack adjuster causes rotation of the S-cam. Rotation of the S-cam forces brake linings or pads to make contact with the brake drum to create friction and thus slow or stop the vehicle. In order for the brake chamber, pushrod, slack adjuster, and cam shaft to operate properly, the brake chamber and the cam shaft assembly must be mounted on a generally stable structural member near the brake drum. More particularly, mounting of the brake chamber and the cam shaft assembly on a generally stable structural member near the brake drum is necessary so that proper alignment of the brake chamber, pushrod, slack adjuster, and cam shaft is maintained, which is important for proper actuation and performance of the brake system.

In spring axle/suspension systems of the prior art, the brake chamber has been mounted on a brake chamber bracket, and the cam shaft assembly has been mounted on a cam shaft assembly mounting bracket, which is also referred to in the art as an S-cam bearing bracket. Because it is not feasible to mount the brake chamber bracket and/or the cam shaft assembly mounting bracket directly on or to a leaf spring, these brackets have been mounted on the axle in the prior art. More particularly, the leaf spring must flex to dampen forces and thus does not provide a stable structural mounting surface. In addition, because a leaf spring is formed with a metallurgical structure that enables it to flex while withstanding significant stress, attempting to mount such brackets directly on or to the leaf spring may significantly decrease the ability of the leaf spring to withstand stress. As a result, the axle central tube, which is a generally stable structural member that is relatively near the brake drum, has been used as a mounting location for the brake chamber bracket and the cam shaft assembly mounting bracket.

More particularly, the brake chamber bracket has been rigidly attached by welding to a front portion of the axle central tube just inboardly of a respective leaf spring stack. Similarly, the cam shaft assembly mounting bracket has been rigidly attached by welding to a rear portion of the axle central tube just inboardly of a respective leaf spring stack. Such prior art mounting of the brake chamber to a bracket that is in tum welded to the axle central tube, and mounting of the cam shaft assembly to a bracket that is also in tum welded to the axle central tube, has provided a generally stable structural mounting configuration that enables sufficient operation of the brake system components. However, this configuration has certain disadvantages, including a susceptibility to stress.

For example, axles typically are hollow, which desirably reduces the amount of material used to manufacture an axle, thereby decreasing manufacturing costs, and also reduces axle weight, thereby reducing vehicle fuel consumption and costs associated with operation of the vehicle. As a result, it is desirable to use an axle with the thinnest possible wall to optimize the material and weight savings.

It is known in the art that the portion of the axle central tube which is between the leaf spring stacks is a high-stress area, due to the transmission of forces and the creation of resulting loads across the axle between the leaf spring stacks during vehicle operation. When a component is welded to a hollow axle central tube, an area on the axle wall adjacent the weld is created that is generally more susceptible to stress than a non-welded area. As a result, when forces and resulting loads act upon the axle, a welded area along the axle central tube is generally more susceptible to possible damage from such forces and/or loads than a non-welded area. In order to compensate for the increased susceptibility to stress that is caused by welds, the wall thickness of the axle typically is increased, which undesirably increases the amount of material used to manufacture the axle, and also increases the weight of the axle. Thus, in the prior art, the use of a brake chamber bracket and a cam shaft assembly mounting bracket that are each welded to the axle central tube has required the use of a relatively-thick-walled axle, which undesirably increases the cost and weight of the axle.

Alternatively in the prior art, air-ride axle/suspension systems, which are different in structure and operation from spring axle/suspension systems, have employed mounting structures in which welding of the brake chamber bracket and/or the cam shaft assembly mounting bracket to the axle central tube was eliminated. However, such mounting structures cannot be employed in a spring axle/suspension system because air-ride axle/suspension systems are different in structure and operation from spring axle/suspension systems. For example, air-ride axle/suspension systems include a pair of transversely-spaced leading or trailing arm box-type beams, in which a first end of each box-type beam is connected to the vehicle subframe, and a second or opposite end of each box- type beam is connected to the axle. In the air-ride axle/suspension system prior art, welding of the brake chamber bracket and/or the cam shaft assembly mounting bracket to the axle central tube was eliminated by mounting the brake chamber and the cam shaft assembly mounting bracket directly on the box-type beam.

Due to the different structural requirements and operation of box-type beams of an air-ride axle/suspension system and leaf springs of a spring axle/suspension system, it is not feasible to attach the brake chamber bracket and the bearing bracket directly to a leaf spring. More particularly, air-ride axle/suspension systems include air springs to dampen certain forces and thus cushion the vehicle ride. As a result, each box-type beam typically is a rigid beam that is fabricated or cast and typically includes one or more sidewalls, an upper wall, and a rear wall, and is rigidly connected to the axle. As described above, in order for the brake chamber, pushrod, slack adjuster and cam shaft to operate properly, the brake chamber and the cam shaft assembly must be mounted on a generally stable structural member near the brake drum. In an air-ride axle/suspension system, the generally rigid nature of each box-type beam and its generally rigid connection to the axle enables the box beam to be used as a stable structural mounting surface for components such as the brake chamber or brake chamber bracket and the cam shaft assembly mounting bracket. In addition since each air-ride axle/suspension system box-type beam includes one or more sidewalls, an upper wall, and a rear wall, sufficient structural surface area is provided to enable components such as the brake chamber or brake chamber bracket and the cam shaft assembly mounting bracket to be attached to the box-type beam.

In contrast, spring axle/suspension systems do not employ air springs, instead relying on the leaf springs to flex and thus dampen forces. Because the leaf springs flex during vehicle operation, they do not provide a sufficient stable structural mounting surface to enable the mounting of components such as the brake chamber or brake chamber bracket and the cam shaft assembly mounting bracket. In addition, because leaf springs are formed with a metallurgical structure that enables them to flex while withstanding significant stress, it is undesirable to attempt to mount such components or brackets on the leaf springs, as such mounting may significantly decrease the ability of the leaf springs to withstand stress. An exemplary axle-to-beam connection for a heavy-duty vehicle axle/suspension system is described in <CIT>.

As a result, a need has existed in the art for a brake component mounting bracket that overcomes the disadvantages of prior art systems by providing a structure that enables a brake chamber and a cam shaft assembly to be rigidly mounted on or adjacent to the axle without welding a brake chamber bracket or a cam shaft assembly mounting bracket to the vehicle axle, thereby enabling a thinner-wall axle to be used, which in turn desirably reduces the weight and cost associated with the axle/suspension system. The integrated brake component mounting bracket for a spring axle/suspension system of the present invention satisfies this need, as will be described below.

An objective of the present invention is to provide a clamp assembly for a mechanical leaf spring axle/suspension system of a heavy duty vehicle that enables a brake chamber and a cam shaft assembly to be rigidly mounted on or adjacent to the vehicle axle without welding a brake chamber bracket or a cam shaft assembly mounting bracket to the axle.

Another objective of the present invention is to provide a clamp assembly for a mechanical leaf spring axle/suspension system of a heavy duty vehicle that enables the use of a thinner-wall axle, thereby reducing the weight and cost associated with the axle/suspension system.

These objectives and others are obtained by the clamp assembly of the present invention as set forth in claim <NUM>. Further aspects of the invention are set forth in the dependent claims.

The preferred embodiments of the present invention, illustrative of the best modes in which Applicant has contemplated applying the principles, are set forth in the following description and are shown in the drawings, and are particularly and distinctly pointed out and set forth in the appended claims.

In order to better understand the integrated brake component mounting bracket of the present invention and the environment in which it operates, a prior art spring axle/suspension system is indicated generally at <NUM> and is shown in <FIG> and <FIG>. Prior art spring axle/suspension system IO is a tandem axle/suspension system, utilizing a front axle/suspension system <NUM> and a rear axle/suspension system <NUM>, each of which is connected to and depends from a vehicle frame or subframe <NUM>, as known in the art.

As mentioned above, in some heavy-duty vehicles, the axle/suspension systems are connected directly to the primary frame of the vehicle, while in other heavy-duty vehicles, the primary frame of the vehicle supports a movable or non-movable subframe, and the axle/suspension systems connect directly to the subframe. For the purpose of convenience, reference herein will be made to subframe <NUM>, with the understanding that such reference is by way of example, and that the present invention applies to heavy-duty vehicle primary frames, movable subframes and non-movable subframes.

Front axle/suspension system <NUM> includes a pair of transversely-spaced, longitudinally-extending mechanical spring suspension assemblies <NUM>, which connect to a front axle 20F. Similarly, rear axle/suspension system <NUM> includes a pair of transversely-spaced, longitudinally-extending mechanical spring suspension assemblies <NUM> (only one of which is shown), which connect to a rear axle 20R. Inasmuch as each one of the pair of front mechanical spring suspension assemblies <NUM> is identical to the other, and each one of the pair of rear mechanical spring suspension assemblies <NUM> is identical to the other, only one of each will be described herein. Front mechanical spring suspension assembly <NUM> includes a leaf spring set or stack <NUM>, which in turn includes one or more leaf springs <NUM>. Rear mechanical spring suspension assembly <NUM> includes a leaf spring set or stack <NUM>, which in turn includes one or more leaf springs <NUM>.

In front mechanical spring suspension assembly <NUM>, front leaf spring <NUM> extends longitudinally between a front hanger <NUM>, which is mounted on and depends from subframe <NUM> in a manner known to those skilled in the art, and an equalizer or rocker <NUM> (<FIG>). Equalizer <NUM> in turn is pivotally connected to a center hanger <NUM> by a pin and bushing assembly <NUM>, and the center hanger is mounted on and depends from subframe <NUM>, as known in the art. In rear mechanical spring suspension assembly <NUM>, rear leaf spring <NUM> extends longitudinally between equalizer <NUM> and a rear hanger <NUM>, which is mounted on and depends from subframe <NUM> in a manner known to those skilled in the art. Also as known in the art, equalizer <NUM> provides a connection between front and rear suspension assemblies <NUM>, <NUM>, respectively, and pivots in order to attempt to balance the loads between front and rear axles 20F, 20R.

Front leaf spring <NUM> is clamped to front axle 20F by a clamp assembly <NUM>. More particularly, clamp assembly <NUM> includes a top block <NUM> that is disposed on the upper surface of leaf spring <NUM> at about the longitudinal midpoint of the top spring, a top axle seat <NUM> that extends between the bottom of the leaf spring and the upper po1iion of front axle 20F in ve1iical alignment with the top block, and a bottom axle seat <NUM>, which is a essentially a curved plate disposed on the lower portion of the front axle in ve1iical alignment with the top block and the top axle seat. Clamp assembly <NUM> also includes a pair of U-bolts <NUM>, each one of which engages top block <NUM> and extends through a pair of openings (not shown) formed in bottom axle seat <NUM>. In this manner, top block <NUM>, front leaf spring <NUM>, top axle seat <NUM>, axle 20F, and bottom axle seat <NUM> are rigidly clamped together when nuts <NUM> are tightened onto threaded ends of U-bolts <NUM>. It is understood that rear leaf spring <NUM> is clamped to rear axle 20R by clamp assembly <NUM> in a manner similar to that as described for front leaf spring <NUM>.

In order to control fore-aft movement of front axle 20F, a front radius rod <NUM> is pivotally connected to and extends between front hanger <NUM> and front axle top axle seat <NUM>. Likewise, to control fore-aft movement of rear axle 20R, a rear radius rod <NUM> is pivotally connected to and extends between center hanger <NUM> and rear axle top axle seat <NUM>.

Inasmuch as each one of front axle 20F and rear axle 20R is identical to the other, only one axle will be described herein. Axle 20F includes a central tube <NUM>, and an axle spindle <NUM> is integrally connected by any suitable means, such as welding, to each end of the central tube. A wheel end assembly (not shown) is rotatably mounted on each axle spindle <NUM>, as known in the art. A brake system <NUM> includes a brake drum <NUM> that is mounted on the wheel end assembly. Inasmuch as each end of axle 20F and its associated spindle <NUM>, the wheel end assembly, brake drum <NUM>, and associated components of brake system <NUM> are generally identical to the other, only one end of the axle and its associated spindle, wheel end assembly, brake drum, and associated components of the brake system will be described herein.

In order to slow or stop the vehicle, compressed air is communicated through air lines <NUM> to a brake air chamber or brake chamber <NUM>, which converts the air pressure into mechanical force and moves a pushrod <NUM> in a longitudinal manner relative to the brake chamber. Pushrod <NUM> is pivotally connected to slack adjuster <NUM> by a pin-and-link assembly or clevis <NUM>, which enables the slack adjuster to convert the longitudinal movement of the pushrod to rotational movement. Slack adjuster <NUM> in turn is connected to an inboard end <NUM> of a cam shaft <NUM> of a cam shaft assembly <NUM>.

As known in the art, cam shaft inboard end <NUM> is splined and meshingly engages a corresponding splined interior surface (not shown) of slack adjuster <NUM>. An S-cam <NUM> (<FIG>) of cam shaft assembly <NUM> is mounted on an outboard end <NUM> of cam shaft <NUM>, whereby rotation of the cam shaft by slack adjuster <NUM> causes rotation of the S-cam. Rotation of S-cam <NUM> forces brake linings or pads <NUM> (<FIG>) to make contact with an inner surface of brake drum <NUM> to create friction and thus slow or stop the vehicle.

Components of cam shaft assembly <NUM> enable smooth, stable rotation of cam shaft <NUM> upon movement of slack adjuster <NUM>. More particularly, cam shaft <NUM> is rotatably mounted in a cam tube <NUM> by bushings (not shown), as known in the art, and extends through the tube. In this manner, inboard end <NUM> of cam shaft <NUM> is exposed in order to engage slack adjuster <NUM>, and outboard end <NUM> (<FIG>) of the cam shaft is also exposed in order to enable S-cam <NUM> to engage brake linings or pads <NUM> (<FIG>). In order to secure the position of cam shaft <NUM> parallel to axle 20F, and to ensure that only the cam shaft rotates, rather than cam tube <NUM>, a cam tube bracket <NUM> receives and retains the inboard end of the cam tube. An exemplary cam tube bracket <NUM> includes an inboard plate <NUM> and an outboard plate <NUM>, each one of which is formed with a plurality of tabs <NUM> (<FIG>) that secure the cam tube, as more fully described in <CIT>, which is assigned to the same assignee as the present invention, Hendrickson USA, L. To support the outboard end of cam tube <NUM> and thus outboard end <NUM> of cam shaft <NUM>, a brake spider <NUM> is immovably mounted on axle 20F, such as by welding, outboardly of spring stack <NUM>. The outboard end of cam tube <NUM> is mounted in a bore <NUM> formed in a collar <NUM> of spider <NUM>, as known in the art.

Alignment of brake chamber <NUM>, pushrod <NUM>, slack adjuster <NUM>, and cam shaft <NUM> is important for proper actuation and perfo1mance of brake system <NUM>, thereby necessitating the mounting of the brake chamber and cam shaft assembly <NUM> on a stable structural member near brake drum <NUM>. In the prior art, such mounting was achieved by mounting brake chamber <NUM> on a brake chamber mounting bracket <NUM>, and by mounting cam tube bracket <NUM> of cam tube assembly <NUM> on a cam shaft assembly mounting bracket <NUM>, which is also referred to in the art as an S-cam bearing bracket.

More particularly, brake chamber <NUM> is mounted on brake chamber mounting bracket <NUM> by mechanical fasteners, such as bolts <NUM>. Brake chamber mounting bracket <NUM> in turn is rigidly attached to axle 20F by welding the bracket to a front portion of axle central tube <NUM> inboardly of leaf spring <NUM>. Similarly, cam tube bracket <NUM> is mounted on cam shaft assembly mounting bracket <NUM> by mechanical fasteners, such as bolts <NUM>. Cam shaft assembly mounting bracket <NUM> in turn is rigidly attached to axle 20F by welding the bracket to a rear portion of axle central tube <NUM> inboardly of leaf spring <NUM>.

When a component such as brake chamber mounting bracket <NUM> and/or cam shaft assembly mounting bracket <NUM> is welded to axle central tube <NUM>, an area on the wall of axle 20F adjacent the weld is created that is generally more susceptible to stress than a non-welded area. Because the portion of axle central tube <NUM> that is between leaf springs <NUM> is known to be a high-stress area due to the transmission of forces and resulting loads across axle 20F during vehicle operation, the welded area of the axle central tube is generally more susceptible to possible damage from such forces and/or loads than a non-welded area. In order to compensate for the increased susceptibility to stress that is caused by welding brake chamber mounting bracket <NUM> and cam shaft assembly mounting bracket <NUM> to axle 20F, the wall thickness of the axle typically is increased. Such an increase in wall thickness undesirably increases the amount of material used to manufacture axle 20F, undesirably increasing the weight of the axle, in tum undesirably increasing manufacturing costs and fuel consumption.

Alternatively in the prior art, air-ride axle/suspension systems, such as an exemplary air-ride axle/suspension system indicated generally at <NUM> and shown in <FIG>, have employed structures in which welding of the brake chamber bracket and/or the bearing bracket to the axle central tube was eliminated, which was enabled by the structural differences between air-ride axle/suspension systems and spring axle/suspension systems <NUM>. More particularly, and as described in greater detail in <CIT>, air-ride axle/suspension system <NUM> includes a pair of transversely-spaced leading or trailing arm box-type beams <NUM>. A first end <NUM> of each box-type beam <NUM> is pivotally connected to a hanger <NUM>, which in tum is rigidly connected to the vehicle subframe <NUM> (<FIG>), and a second end <NUM> of each box-type beam is rigidly connected to axle <NUM>. Air-ride axle/suspension system <NUM> includes air springs <NUM> to cushion the vehicle ride and provide some damping characteristics, enabling each box-type beam <NUM> to be a rigid beam that is fabricated or cast, and which includes one or more sidewalls <NUM>, an upper wall <NUM>, and a rear wall <NUM>.

In air-ride axle/suspension system <NUM>, brake chamber <NUM> is mounted directly on box-type beam rear wall <NUM> by brake chamber bolts <NUM> and nuts <NUM>. A cam shaft assembly mounting bracket <NUM> is connected to a selected one of beam sidewalls <NUM> by bolts <NUM> and nuts <NUM>, and supports cam shaft assembly <NUM>, which is mounted on the bracket. With this structure, brake chamber <NUM> moves pushrod <NUM> upon actuation. Pushrod <NUM> in tum moves slack adjuster <NUM>, as enabled by the pivotal connection of the pushrod to the slack adjuster. Slack adjuster <NUM> is operatively connected to cam shaft <NUM> of cam shaft assembly <NUM>, enabling rotation of the cam shaft upon movement of the slack adjuster. Rotation of cam shaft <NUM> by slack adjuster <NUM> causes rotation of S-cam <NUM>, which is mounted on outboard end <NUM> of the cam shaft. Rotation of S-cam <NUM> forces brake linings or pads <NUM> (<FIG>) to make contact with an inner surface of brake drum <NUM> (<FIG>) to create friction and thus slow or stop the vehicle. It is understood that, while cam shaft assembly <NUM> is shown in <FIG> without cam tube <NUM>, the cam shaft assembly may employ the cam tube and its associated components, in a manner similar to that as described above.

Alignment of brake chamber <NUM>, pushrod <NUM>, slack adjuster <NUM>, and cam shaft <NUM> is important for proper actuation and performance of brake system <NUM>, thereby necessitating the mounting of the brake chamber and cam shaft assembly <NUM> on a stable structural member near brake drum <NUM>. In air-ride axle/suspension system <NUM>, the rigid nature of each box-type beam <NUM> and its rigid connection to axle <NUM> enables the box beam to be used as a stable structural mounting surface for brake chamber <NUM> and cam shaft assembly mounting bracket <NUM>. In addition, since each air- ride axle/suspension system box-type beam <NUM> includes sidewalls <NUM>, upper wall <NUM>, and rear wall <NUM>, sufficient structural surface area is provided to enable the mounting of brake chamber <NUM> and cam shaft assembly mounting bracket <NUM> to the box-type beam.

In contrast, as shown in <FIG> and <FIG>, spring axle/suspension system <NUM> does not employ air springs <NUM> (<FIG>), instead relying on leaf springs <NUM>, <NUM> to flex and thus dampen forces. Because leaf springs <NUM>, <NUM> flex during vehicle operation, they do not provide a sufficient stable structural mounting surface to enable the mounting of brake chamber <NUM>, brake chamber bracket <NUM>, and/or cam shaft assembly mounting bracket <NUM>, <NUM>. In addition, because leaf springs <NUM>, <NUM> are formed with a metallurgical structure that enables them to flex while withstanding significant stress, it is undesirable to attempt to mount brake chamber <NUM>, brake chamber bracket <NUM>, and/or cam shaft assembly mounting bracket <NUM>, <NUM> on the leaf springs, as such mounting may significantly decrease the ability of the leaf springs to withstand stress.

Therefore, there is a need in the art for a brake component mounting bracket that overcomes the disadvantages of prior mi systems by providing a structure that enables a brake chamber and a cam shaft assembly to be rigidly mounted in conjunction with a spring axle/suspension system without welding a brake chamber bracket or a cam shaft assembly mounting bracket to the vehicle axle, thereby enabling a thinner-wall axle to be used. The integrated brake component mounting bracket for a spring axle/suspension system of the present invention satisfies this need, as will now be described.

Turning to the drawings of the present invention, wherein the illustrations are for showing the preferred embodiment of the invention, and not for limiting the same, <FIG> show a first exemplary embodiment of a clamp assembly of the present invention, indicated generally at <NUM>, for a spring axle/suspension system. In order to better understand integrated brake component mounting bracket <NUM> and the environment in which it operates, an exemplary spring axle/suspension system incorporating the integrated mounting bracket is indicated generally at <NUM>, and is more fully described in <CIT>, by the same assignee, Hendrickson USA, L.

Referring now to <FIG>, spring axle/suspension system <NUM> is a tandem system, utilizing a front axle/suspension system <NUM> and a rear axle/suspension system <NUM>, each of which is connected to and depends from a vehicle subframe <NUM>. It is to be understood that in some heavy-duty vehicles, the axle/suspension systems are connected directly to the primary frame of the vehicle, while in other heavy-duty vehicles, the primary frame of the vehicle supports a movable or non-movable subframe, and the axle/suspension systems connect directly to the subframe. For the purpose of convenience, reference herein will be made to subframe <NUM>, with the understanding that such reference is by way of example, and that the present invention applies to heavy-duty vehicle primary frames, movable subframes and non-movable subframes.

Subframe <NUM> includes a pair of longitudinally-extending, parallel, transversely-spaced elongated main members <NUM>. A plurality of longitudinally-spaced parallel cross members <NUM> extend transversely between and are attached to main members <NUM>. Pairs of transversely spaced hangers, including front hangers <NUM>, center hangers <NUM>, and rear hangers <NUM>, are mounted on and depend from main members <NUM> and selected ones of cross members <NUM>. It should be noted that, while hangers <NUM>, <NUM>, <NUM> are sometimes considered to be part of subframe <NUM> once they are connected to main members <NUM> and selected ones of cross members <NUM>, they are typically engineered as part of spring axle/suspension system <NUM>.

Front axle/suspension system <NUM> includes a pair of transversely-spaced, longitudinally-extending mechanical spring suspension assemblies <NUM>, which connect to a front axle 120F. Similarly, rear axle/suspension system <NUM> includes a pair of transversely-spaced, longitudinally-extending mechanical spring suspension assemblies <NUM>, which connect to a rear axle 120R. Inasmuch as each one of the pair of front mechanical spring suspension assemblies <NUM> is identical to the other, and each one of the pair of rear mechanical spring suspension assemblies <NUM> is identical to the other, only one of each will be described herein. Front mechanical spring suspension assembly <NUM> includes a pair of transversely-spaced leaf spring sets or stacks <NUM>, and rear mechanical spring suspension assembly <NUM> includes a pair of transversely-spaced leaf spring sets or stacks <NUM>.

Front spring stack <NUM> preferably includes a top leaf spring <NUM> and a bottom leaf spring <NUM>. Top leaf spring <NUM> extends longitudinally between front hanger <NUM> and an equalizer or rocker <NUM>. Rear spring stack <NUM> preferably includes a top leaf spring <NUM> and a bottom leaf spring <NUM>, and extends longitudinally between equalizer <NUM> and rear hanger <NUM>. As known in the art, equalizer <NUM> provides a connection between front and rear suspension assemblies <NUM>, <NUM>, respectively, and is able to pivot in order to help balance the loads between front and rear axles 120F, 120R.

Each spring stack <NUM>, <NUM> is clamped to its respective axle 120F, 120R by a clamp assembly <NUM>. More particularly, and with reference now to <FIG> and <FIG>, clamp assembly <NUM> includes an upper plate <NUM>, a top axle seat <NUM>, integrated brake component mounting bracket <NUM>, and a pair of U-bolts <NUM>. Upper plate <NUM> is disposed on an upper surface of each top leaf spring <NUM>, <NUM> at about the longitudinal midpoint of each respective spring. Top axle seat <NUM> is disposed between a bottom surface of each bottom leaf spring <NUM>, <NUM> and the upper portion of each respective axle 120F, 120R in general vertical alignment with upper plate <NUM>. In association with first embodiment clamp assembly, top axle seat <NUM> preferably is welded to each respective axle 120F, 120R. Integrated brake component mounting bracket <NUM>, which will be described in greater detail below, is disposed on a lower portion of each axle 120F, 120R in general vertical alignment with upper plate <NUM> and top axle seat <NUM>, and in the first embodiment of the invention, preferably is welded to each respective axle.

A curved apex <NUM> of each U-bolt <NUM> engages and secures upper plate <NUM>, while each threaded end <NUM> of each U-bolt passes through an opening <NUM> formed in a respective boss <NUM>, which in tum is formed on integrated brake component mounting bracket <NUM>. In this manner, upper plate <NUM>, top leaf spring <NUM>, <NUM>, bottom leaf spring <NUM>, <NUM>, top axle seat <NUM>, axle 120F, 120R, and integrated brake component mounting bracket <NUM> are rigidly clamped and secured together when nuts <NUM> are tightened onto threaded U-bolt ends <NUM>. Preferably, a center bolt <NUM> extends through each respective upper plate <NUM>, top leaf spring <NUM>, <NUM>, bottom leaf spring <NUM>, <NUM> and top axle seat <NUM> to provide an additional interconnection of the springs and clamp assembly <NUM>.

With particular reference now to <FIG>, integrated brake component mounting bracket <NUM> includes a bottom axle seat <NUM>, an air chamber mounting bracket <NUM>, and a cam shaft assembly mounting bracket <NUM>, which is also referred to as an S-cam bearing bracket. More particularly, bottom axle seat <NUM> is a curved plate that seats against a lower portion of each axle 120F, 120R and preferably is welded to each respective axle in the first embodiment of the invention. Bottom axle seat includes a front portion <NUM> and a rear portion <NUM>, and bosses <NUM> are integrally formed on the seat to receive U-bolts <NUM>, as described above.

With additional reference to <FIG>, air chamber mounting bracket <NUM> of integrated brake component mounting bracket <NUM> is rigidly attached to front portion <NUM> of bottom axle seat <NUM>. More particularly, air chamber mounting bracket <NUM> includes a mounting plate <NUM> that is disposed generally parallel to each respective transversely-extending axle 120F, 120R. Mounting plate <NUM> is formed with openings <NUM> to accept bolts <NUM> of a brake chamber <NUM>, which are secured to the mounting plate with nuts <NUM>. A central opening <NUM> is also formed in mounting plate <NUM> to enable a brake chamber pushrod <NUM> to extend through air chamber mounting bracket <NUM> and connect to a slack adjuster <NUM>. Outboardly of central opening <NUM>, a connecting plate <NUM> is rigidly attached to a rear surface <NUM> of mounting plate <NUM>, preferably by welding or integral forming, and extends perpendicular to axle 120F, 120R to front portion <NUM> of bottom axle seat <NUM>. Connecting plate <NUM> is rigidly attached, preferably by welding or integral forming, to front portion <NUM> of bottom axle seat <NUM> inboardly of an outboard front one l 70A of bosses <NUM>. In this manner, connecting plate <NUM> enables the rigid attachment of mounting plate <NUM> in alignment with, rather than being inboardly offset from, bottom axle seat <NUM>, thereby providing desired stability of air chamber mounting bracket <NUM>.

With continuing reference to <FIG> and <FIG>, cam shaft assembly mounting bracket <NUM> of integrated brake component mounting bracket <NUM> is rigidly attached to rear portion <NUM> of bottom axle seat <NUM>. Cam shaft assembly mounting bracket <NUM> extends perpendicular to axle 120F, 120R and is rigidly attached to rear portion <NUM> of bottom axle seat, preferably by welding or integral forming, outboardly of an outboard rear one 170B of bosses <NUM>. Cam shaft assembly mounting bracket <NUM> is formed with an opening <NUM> to enable a cam tube <NUM> of a cam shaft assembly <NUM> to extend through the bearing bracket, as will be described in greater detail below. Cam shaft assembly mounting bracket <NUM> is also formed with a plurality of slots <NUM> adjacent opening <NUM> to accept fasteners, such as bolts <NUM>, which are secured with nuts <NUM>, to enable the mounting of a cam tube bracket <NUM> on the cam shaft assembly mounting bracket, as also will be described in greater detail below. In this manner, cam shaft assembly mounting bracket <NUM> enables the rigid attachment of cam shaft assembly <NUM> to bottom axle seat <NUM>, thereby providing desired stability of the cam shaft assembly.

Turning now to <FIG>, components of a brake system <NUM> are shown installed on integrated brake component mounting bracket <NUM>. Inasmuch as each one of front axle 120F and rear axle 120R (<FIG>) is identical to the other, only one axle will be described herein. Axle 120F includes a central tube <NUM>, and an axle spindle <NUM> is integrally connected by any suitable means, such as welding, to each end of the central tube. A wheel end assembly (not shown) is rotatably mounted on each axle spindle <NUM>, as known in the art. Brake system <NUM> includes a brake drum <NUM> (<FIG>) that is mounted on the wheel end assembly. Inasmuch as each end of axle 120F and its associated spindle <NUM>, the wheel end assembly, brake drum <NUM>, and associated components of brake system <NUM> are generally identical to the other, only one end of the axle and its associated spindle, wheel end assembly, brake drum, and associated components of brake system will be described herein.

In order to slow or stop the vehicle, compressed air is communicated through air lines <NUM> (<FIG>) to brake chamber <NUM>, which is securely mounted on the front of integrated brake component mounting bracket <NUM>. More particularly, bolts <NUM> of brake chamber <NUM> extend through openings <NUM> (<FIG>) formed in mounting plate <NUM> of air chamber mounting bracket <NUM>,
and are secured to the mounting plate with nuts <NUM>. Pushrod <NUM> extends rearwardly from brake chamber <NUM> through central opening <NUM> formed in mounting plate <NUM>, and extends below bottom axle seat <NUM> of integrated brake component mounting bracket <NUM>. Pushrod <NUM> pivotally connects to slack adjuster <NUM> by an offset pin-and-link assembly or clevis <NUM>, which will be described in greater detail below, and enables the slack adjuster to convert the longitudinal movement of pushrod <NUM> to rotational movement.

Slack adjuster <NUM> in tum is connected to an inboard end <NUM> of a cam shaft <NUM> of cam shaft assembly <NUM>. As known in the art, cam shaft inboard end <NUM> preferably is splined and meshingly engages a corresponding splined interior surface (not shown) of slack adjuster <NUM>. Components of cam shaft assembly <NUM> enable smooth, stable rotation of cam shaft <NUM> upon movement of slack adjuster <NUM>. More particularly, can1 shaft <NUM> is rotatably mounted in a cam tube <NUM> by bushings (not shown), as known in the art, and extends through the tube. In this manner, inboard end <NUM> of a cam shaft <NUM> is exposed in order to engage slack adjuster <NUM>, and an outboard end of the cam shaft is also exposed in order to enable S-cam <NUM> (<FIG>), which is mounted on the outboard end of the cam shaft, to engage brake linings or pads <NUM>. As a result, rotation of cam shaft <NUM> by slack adjuster <NUM> causes rotation of S-cam <NUM> to force brake linings or pads <NUM> to make contact with an inner surface of brake drum <NUM> (<FIG>) to create friction and thus slow or stop the vehicle.

To ensure that only cam shaft <NUM> rotates, rather than cam tube <NUM>, cam tube bracket <NUM> receives and retains the inboard end of the cam tube. An exemplary cam tube bracket <NUM> includes an inboard plate <NUM> and an outboard plate <NUM>, each one of which is formed with a plurality of tabs <NUM> that secure the cam tube, as more fully described in <CIT>, which is assigned to the same assignee as the present invention, Hendrickson USA, L. To support the outboard end of cam tube <NUM> and thus the outboard end of cam shaft <NUM>, a brake spider <NUM> is immovably mounted on axle 120F, such as by welding, outboardly of spring stack <NUM>. The outboard end of cam tube <NUM> is mounted in a bore <NUM> formed in a collar <NUM> of the spider, as known in the art.

Secure and stable mounting of cam shaft assembly <NUM> is provided by cam shaft assembly mounting bracket <NUM> of integrated brake component mounting bracket <NUM>. More particularly, cam shaft assembly mounting bracket <NUM> is rigidly attached to rear portion <NUM> of bottom axle seat <NUM>, as described above, and extends rearwardly from axle 120F. Cam tube <NUM> and cam shaft <NUM> extend through opening <NUM> (<FIG>), as do tabs <NUM> of outboard plate <NUM> of cam tube bracket <NUM>. In this manner, cam shaft assembly mounting bracket <NUM> enables cam tube bracket <NUM> to prevent rotation of cam tube <NUM>, while providing a secure mounting location for the cam tube bracket. Such mounting is provided by slots <NUM> formed in cam shaft assembly mounting bracket <NUM>, which align with openings (not shown) formed in inboard plate <NUM> and outboard plate <NUM> of cam tube bracket <NUM>. Fasteners, such as bolts <NUM>, pass through each one of respective aligned openings in cam tube bracket <NUM> and slots <NUM>, thereby enabling the cam tube bracket to be secured to cam shaft assembly mounting bracket <NUM> when nuts <NUM> are tightened.

As a result of the structural integration of cam shaft assembly mounting bracket <NUM> to rear portion <NUM> of bottom axle seat <NUM>, integrated brake component mounting bracket <NUM> provides rigid attachment of cam shaft assembly <NUM> to bottom axle seat <NUM>, thereby providing desired stability and positioning of the cam shaft assembly. Likewise, as a result of the structural integration of air chamber mounting bracket <NUM> to front portion <NUM> of bottom axle seat <NUM>, integrated brake component mounting bracket <NUM> provides rigid attachment of brake chamber <NUM> to bottom axle seat <NUM>, thereby providing desired stability and positioning of the brake chamber.

In this manner, integrated brake component mounting bracket <NUM> provides a structure that enables brake chamber <NUM> and cam shaft assembly <NUM> to be rigidly mounted on or adjacent each axle 120F, 120R, without welding a brake chamber bracket and/or a cam shaft assembly mounting bracket to the vehicle axle. As described above, prior art brake chamber mounting bracket <NUM> and cam shaft assembly mounting bracket <NUM> (<FIG>) were welded to axle central tube <NUM> between leaf spring stacks <NUM>, <NUM>. This is a high-stress area due to the transmission of forces and the creation of resulting loads across each axle 20F, 20R during vehicle operation. As a result, when a component is welded to hollow axle central tube <NUM>, an area on the axle wall adjacent the weld is created that is generally more susceptible to stress than a non-welded area, and when forces and resulting loads act upon axle 20F, 20R, the welded area is generally more susceptible to possible damage than a non- welded area. As a result, by eliminating the welding of brackets to each axle 120F, 120R, integrated brake component mounting bracket <NUM> enables each axle to be less susceptible to possible damage.

In addition, to compensate for the increased susceptibility to stress that was caused by welds, prior art axles 20F, 20R were formed with an increased wall thickness. Because integrated brake component mounting bracket <NUM> enables elimination of the welding of a brake chamber bracket and/or a cam shaft assembly mounting bracket to each axle 120F, 120R, each axle can be formed with a thinner wall. For example, prior art axle 20F, 20R typically includes a wall thickness of about <NUM> (<NUM> inches) with a <NUM> (<NUM> inch) diameter, while each axle 120F, 120R used in conjunction with integrated brake component mounting bracket <NUM> preferably includes a wall thickness of about <NUM> (<NUM> inches) with a <NUM> (<NUM> inch) diameter. Such reduction of the wall thickness of each axle 120F, 120R in turn desirably reduces the cost associated with manufacturing axle/suspension system <NUM> employing integrated brake component mounting bracket <NUM>, as the amount of material used to manufacture each axle is reduced. Moreover, the reduction of the wall thickness of each axle 120F, 120R desirably reduces the cost to operate a vehicle that employs axle/suspension system <NUM> with integrated brake component mounting bracket <NUM>, as axle weight is reduced, which in turn reduces vehicle fuel consumption and the resulting costs associated with operation of the vehicle.

It is to be understood that installation of components of brake system <NUM> on integrated brake component mounting bracket <NUM> is enabled by adjustment of the geometry of certain brake components. More particularly, prior art cam shaft <NUM>, pin and link assembly or clevis <NUM>, and pushrod <NUM> (<FIG> and <FIG>) cannot be employed on integrated brake component mounting bracket <NUM>, as these prior art components do not provide sufficient clearance for component installation on the integrated brake component mounting bracket. Moving brake chamber <NUM> and components of cam shaft assembly <NUM> from a location between leaf spring stacks <NUM>, <NUM>, respectively, to a location beneath each respective spring stack <NUM>, <NUM> (<FIG>) increases the difficulty of assembling components due to the reduced clearances that exist beneath the spring stacks.

With reference to <FIG> and <FIG>, assembly of components on integrated brake component mounting bracket <NUM> is enabled by cam shaft <NUM>, which is shorter in length than prior art cam shaft <NUM> (<FIG>). A shorter length of cam shaft <NUM> enables slack adjuster <NUM> to be disposed between rear bosses <NUM> on bottom axle seat <NUM>. In addition, pin and link assembly or clevis <NUM> is an offset configuration, as compared to the in-line configuration of prior art pin and link assembly or clevis <NUM>. The offset configuration of clevis <NUM> allows pushrod <NUM> to be aligned inboardly of slack adjuster <NUM>, which provides a clearance between the pushrod, the clevis, the slack adjustor and the vehicle tires, and also provides sufficient clearance to install nuts <NUM> onto U-bolts <NUM> to secure clamp assembly <NUM>. Moreover, pushrod <NUM> is longer than prior art pushrod <NUM>, which provides clearance to install nuts <NUM> onto U-bolts <NUM> to secure clamp assembly <NUM>, and to install nuts <NUM> on bolts <NUM> to secure brake chamber <NUM> to air chamber mounting plate <NUM>. As a result, integrated brake component mounting bracket <NUM> cooperates with the specific geometry of components such as cam shaft <NUM>, pin and link assembly or clevis <NUM>, and pushrod <NUM>, to provide secure mounting and optimum positioning of brake chamber <NUM> and cam shaft assembly <NUM>.

Turning now to <FIG>, a second exemplary embodiment of a clamp assembly for a spring axle/suspension system of the present invention. Second embodiment clamp assembly is generally similar in structure and operation to first embodiment clamp assembly <NUM> (<FIG>), with the exception that the second embodiment clamp assembly employs a structure that reduces or eliminates welding of the integrated brake component mounting bracket and top axle seat <NUM> to axle 120F, 120R. As a result, only the differences between second embodiment clamp assembly and first embodiment clamp assembly <NUM> will be described below.

As described above, bottom axle seat <NUM> of axle integrated brake component mounting bracket <NUM> and top axle seat <NUM> preferably are welded to each respective axle 120F, 120R. In certain applications, it may be desirable to reduce or eliminate such welding, which enables axle 120F, 120R to be formed with an even thinner wall when employing second embodiment clamp assembly when compared to first embodiment clamp assembly <NUM>. To reduce or eliminate such welding, the integrated brake component mounting bracket <NUM> and a top axle seat <NUM> of the second embodiment clamp assembly utilize mechanical attachment to each respective axle 120F, 120R.

More particularly, with reference to <FIG>, each respective axle 120F, 120R is formed with an opening (not shown) in an upper or top area <NUM> of the axle beneath top axle seat <NUM>. A c01responding opening <NUM> is fom1ed in a curved axle mounting plate <NUM> of top axle seat <NUM>, which is the portion of the top axle seat that contacts the axle. A dowel <NUM> extends through the opening in upper axle area <NUM> and through aligned opening <NUM> formed in curved axle mounting plate <NUM>. Preferably, dowel <NUM> is secured to axle 120F, 120R and to curved axle mounting plate <NUM> by welding. An aligned opening <NUM> may be formed in an upper plate <NUM> of the top axle seat <NUM> in order to provide access to the opening in upper axle area <NUM>, opening <NUM> in curved axle mounting plate <NUM>, and/or dowel <NUM>. The positive mechanical engagement of dowel <NUM> in the opening in upper axle area <NUM> and opening <NUM> in curved axle mounting plate <NUM> secures the position of top axle seat <NUM> on axle 120F, 120R, respectively.

Turning to <FIG>, similar to first embodiment clamp assembly <NUM>, second embodiment clamp assembly includes bottom axle seat <NUM>, air chamber mounting bracket <NUM>, and cam shaft assembly mounting bracket <NUM>. However, each respective axle 120F, 120R is formed with an opening (not shown) in a lower or bottom area <NUM> of the axle, and bottom axle seat <NUM> of integrated brake component mounting bracket <NUM> is formed with a corresponding opening <NUM>. A dowel <NUM> extends through the opening in lower axle area <NUM> and aligned opening <NUM> formed in bottom axle seat <NUM>. Preferably, dowel <NUM> is secured to axle 120F, 120R and to bottom axle seat <NUM> by welding. The positive mechanical engagement of dowel <NUM> in the opening in lower axle area <NUM> and opening <NUM> in bottom axle seat <NUM> secures the position of integrated brake component mounting bracket <NUM> on axle 120F, 120R, respectively.

In this manner, dowels <NUM>, <NUM> provide positive mechanical engagement of top axle seat <NUM> and integrated brake component mounting bracket <NUM> with each axle 120F, 120R, respectively. This positive mechanical engagement combines with the clamp action of U-bolts <NUM> and nuts <NUM> (<FIG>) to secure top axle seat <NUM> and integrated brake component mounting bracket <NUM> to each respective axle 120F, 120R, thereby eliminating the need to weld the top axle seat and bottom axle seat <NUM> of the integrated brake component mounting bracket to each axle. Elimination of such welding enables axle 120F, 120R to be formed with a thim 1er wall when employing second embodiment clamp assembly, as compared to first embodiment clamp assembly <NUM>.

Such reduction of the wall thickness of each axle 120F, 120R in tum desirably reduces the cost associated with manufacturing an axle/suspension syste1n using second embodiment clamp assembly, as the amount of material used to manufacture each axle is reduced. Moreover, the reduction of the wall thickness of each axle 120F, 120R desirably reduces the cost to operate a vehicle that employs an axle/suspension system with second embodiment clamp assembly, as axle weight is reduced, which reduces vehicle fuel consumption and the resulting costs associated with operation of the vehicle.

In regard to the mechanical attachment of top axle seat <NUM> and second embodiment clamp assembly to each respective axle 120F, 120R, it is to be understood that other means of mechanical engagement of the top axle seat and the integrated brake component mounting bracket to each axle may be used, without affecting the concept or operation of the invention. For example, dimpling of top axle seat <NUM>, integrated brake component mounting bracket <NUM>, axle 120F, 120R, and/or an associated axle sleeve, as described in Application Serial No. <CIT>, which is assigned to the same assignee as the present invention, Hendrickson USA, L. , may be employed.

It is to be understood that integrated brake component mounting bracket of the present invention <NUM>, <NUM>, may be employed in conjunction with types of spring axle/suspension systems other than those shown and described herein, without affecting the overall concept or operation of the invention. For example, with reference to <FIG> and using second embodiment clamp assembly by way of example, the integrated brake component mounting bracket is shown incorporated into a spring axle/suspension system <NUM> that includes radius rods 282F, 282R. More particularly, certain types of spring axle/suspension systems include radius rods 282F, 282R to maintain axle alignment and to react brake forces and other fore-aft forces. For example, in order to control fore-aft movement of front axle 120F, a front radius rod 282F may be pivotally connected to and extend between a front hanger <NUM> and a front top axle seat <NUM>. Likewise, to control fore-aft movement of rear axle 120R, a rear radius rod 282R may be pivotally connected to and extend between a center hanger <NUM> and rear top axle seat <NUM>.

The structure and operation of integrated brake component mounting bracket <NUM> as incorporated into spring axle/suspension system <NUM> with radius rods 282F, 282R is the same as described above, as the bracket includes bottom axle seat <NUM>, air chamber mounting bracket <NUM>, and cam shaft assembly mounting bracket <NUM>. Bottom axle seat <NUM> is disposed on a lower portion of each respective axle 120F, 120R in vertical alignment with each respective top axle seat <NUM>, <NUM>, and is connected to each axle in the same manner that is described above. Integrated brake component mounting bracket <NUM> thus provides a structure that enables brake chamber <NUM> and cam shaft assembly <NUM> to be rigidly mounted on or adjacent each axle 120F, 120R of spring axle/suspension system <NUM> without welding a brake chamber bracket and/or a cam shaft assembly mounting bracket to the vehicle axle. Reduction or elimination of such welding reduces the susceptibility of axle 120F, 120R to possible damage, and enables the axle to be formed with a thinner wall, thereby desirably reducing the weight and cost associated with the axle.

Turning now to <FIG>, an exemplary integrated brake component mounting bracket for use with a spring axle/suspension system of the present invention is indicated generally at <NUM>. More particularly, the first and second embodiments clamp assemblies of the present invention, respectfully, are shown and/or described in use on overslung spring axle/suspension systems <NUM> (e.g., <FIG>), in which springs <NUM>, <NUM> are disposed above or over each respective axle 120F, 120R. The integrated brake component mounting bracket <NUM> applies to underslung axle/suspension systems, in which the springs are disposed below or under each respective axle.

With particular reference to <FIG> and <FIG>, an exemplary underslung axle/suspension system is indicated at <NUM>, and is a tandem system, utilizing a front axle/suspension system <NUM> and a rear axle/suspension system <NUM>, each of which is connected to and depends from a vehicle subframe <NUM>. Front axle/suspension system <NUM> includes a pair of transversely-spaced, longitudinally-extending mechanical spring suspension assemblies <NUM>, which connect to front axle 120F. Similarly, rear axle/suspension system <NUM> includes a pair of transversely-spaced, longitudinally-extending mechanical spring suspension assemblies <NUM>, which connect to rear axle 120R. Inasmuch as each one of the pair of front mechanical spring suspension assemblies <NUM> is identical to the other, and each one of the pair of rear mechanical spring suspension assemblies <NUM> is identical to the other, only one of each will be described herein.

Front mechanical spring suspension assembly <NUM> includes a pair of transversely-spaced leaf spring sets or stacks <NUM>, and rear mechanical spring suspension assembly <NUM> includes a pair of transversely-spaced leaf spring sets or stacks <NUM>. Similar to axle/suspension system <NUM> described above (<FIG>), front spring stack <NUM> preferably includes a top leaf spring <NUM> and a bottom leaf spring <NUM>. Top leaf spring <NUM> extends longitudinally between a front hanger <NUM> and an equalizer or rocker <NUM>. Rear spring stack <NUM> preferably includes a top leaf spring <NUM> and a bottom leaf spring <NUM>, and extends longitudinally between equalizer <NUM> and a rear hanger <NUM>. Exemplary underslung axle/suspension system also includes radius rods 282F, 282R. Front radius rod 282F preferably is pivotally connected to and extends between front hanger <NUM> and a clamp assembly <NUM>, as will be described in greater detail below. Rear radius rod 282R preferably is pivotally connected to and extends between a center hanger <NUM> and clamp assembly <NUM>, also as will be described in greater detail below.

Each spring stack <NUM>, <NUM> is clamped to its respective axle l20F, l20R by clamp assembly <NUM>. More particularly, and with reference now to <FIG> and <FIG>, clamp assembly <NUM> includes integrated brake component mounting bracket <NUM>, a bottom axle seat <NUM>, a bottom spring seat <NUM>, and a pair of U-bolts <NUM>. Bottom spring seat <NUM> is disposed on a lower surface of each bottom spring <NUM>, <NUM> at about the longitudinal midpoint of each respective spring. Each bottom spring seat <NUM> is pivotally connected to a respective one of front and rear radius rods 282F, 282R, so that the front radius rod extends between and pivotally connects to the spring seat beneath front spring stack <NUM> to front hanger <NUM>, and the rear radius rod extends between and pivotally connects to the spring seat beneath rear spring stack <NUM> and center hanger <NUM>.

Bottom axle seat <NUM> is disposed between an upper surface of each top spring <NUM>, <NUM> and a lower surface of each respective axle 120F, 120R in general vertical alignment with bottom spring seat <NUM>. Preferably, each respective axle 120F, 120R is formed with an opening (not shown) in a lower or bottom area <NUM> of the axle above bottom axle seat <NUM>. A corresponding opening (not shown) is formed in a curved axle mounting plate <NUM> of bottom axle seat <NUM>, which is the portion of the bottom axle seat that contacts the axle. A dowel (not shown) extends through the opening in lower axle area <NUM> and through the aligned opening formed in curved axle mounting plate <NUM>. Preferably, the dowel is secured to axle 120F, 120R and to curved axle mounting plate <NUM> by welding. The positive mechanical engagement of the dowel in the opening in lower axle area <NUM> and the opening in curved axle mounting plate <NUM> secures the position of bottom axle seat <NUM> on axle 120F, 120R, respectively. Alternatively, other means, such as welding or alternate mechanical means such as those described above, may be used to secure bottom axle seat <NUM> to each respective axle 120F, 120R.

Integrated brake component mounting bracket <NUM> is disposed on an upper portion <NUM> of each axle 120F, 120R in general vertical alignment with bottom spring seat <NUM> and bottom axle seat <NUM>, and is connected to each respective axle in a manner that will be described in greater detail below. To secure clamp assembly <NUM>, curved apex <NUM> of each U-bolt <NUM> engages and secures integrated brake component mounting bracket <NUM>, while threaded end <NUM> of each U-bolt passes through an opening <NUM> formed in a respective boss <NUM>, which in turn is formed on bottom spring seat <NUM>. In this manner, integrated brake component mounting bracket <NUM>, axle 120F, 120R, bottom axle seat <NUM>, top leaf spring <NUM>, <NUM>, bottom leaf spring <NUM>, <NUM>, and bottom spring seat <NUM> are rigidly clamped and secured together when nuts <NUM> are tightened onto threaded U-bolt ends <NUM>.

With particular reference now to <FIG>, integrated brake component mounting bracket <NUM> includes a top axle seat <NUM>, an air chamber mounting bracket <NUM>, and a cam shaft assembly mounting bracket <NUM>, which is also referred to as an S-cam bearing bracket. More particularly, top axle seat <NUM> is a curved plate that seats against upper portion <NUM> of each axle 120F, 120R. Each respective axle 120F, 120R is formed with an opening (not shown) in its upper or top area <NUM> of the axle, and top axle seat <NUM> of integrated brake component mounting bracket <NUM> is formed with a corresponding opening <NUM>. A dowel <NUM> extends through the opening in upper axle area <NUM> and aligned opening <NUM> formed in top axle seat <NUM>. Preferably, dowel <NUM> is secured to axle 120F, 120R and to top axle seat <NUM> by welding. The positive mechanical engagement of dowel <NUM> in the opening in upper axle area <NUM> and opening <NUM> in top axle seat <NUM> secures the position of integrated brake component mounting bracket <NUM> on axle 120F, 120R, respectively. Alternatively, other means, such as welding or alternate mechanical means such as those described above, may be used to secure top axle seat <NUM> to each respective axle 120F, 120R.

Top axle seat <NUM> includes mechanical features such as tabs <NUM>, which are integrally formed on the seat to retain the alignment of U-bolts <NUM>. Due to space constraints imposed by underslung axle/suspension system <NUM>, top axle seat <NUM> extends inboardly along upper axle area <NUM>, forming an inboard extension <NUM>. Inboard extension <NUM> includes a front portion <NUM> and a rear portion <NUM>, and air chamber mounting bracket <NUM> is rigidly attached to the rear portion of the inboard extension.

More particularly, as best shown in <FIG>, air chamber mounting bracket <NUM> is similar to air chamber mounting bracket <NUM> of first embodiment clamp assembly <NUM> (<FIG>), and thus includes mounting plate <NUM> that is disposed generally parallel to each respective transversely-extending axle 120F, 120R. Mounting plate <NUM> is formed with openings <NUM> to accept bolts <NUM> of brake chamber <NUM>, which are secured to the mounting plate with nuts <NUM>. A central opening <NUM> is also formed in mounting plate <NUM> to enable brake chamber pushrod <NUM> to extend through air chamber mounting bracket <NUM> and connect to slack adjuster <NUM>. Inboardly and outboardly of central opening <NUM>, connecting plates <NUM> are rigidly attached to a front surface <NUM> of mounting plate <NUM>, preferably by welding or integral forming, and extend perpendicular to axle 120F, 120R to rear portion <NUM> of inboard extension <NUM>. Connecting plates <NUM> are rigidly attached, preferably by welding or integral forming, to rear portion <NUM> of inboard extension <NUM>. Such rigid attachment of mounting plate <NUM> to inboard extension <NUM> of top axle seat <NUM> immediately inboard and adjacent each respective spring stack <NUM>, <NUM> provides desired stability of brake chamber <NUM>.

With reference now to <FIG> and <FIG>, cam shaft assembly mounting bracket <NUM> of integrated brake component mounting bracket <NUM> extends perpendicular to axle 120F, 120R and is rigidly attached to front portion <NUM> of inboard extension <NUM>, preferably by welding or integral forming, inboardly of an inboard one of U-bolts <NUM>. Cam shaft assembly mounting bracket <NUM> is similar to cam shaft assembly mounting bracket <NUM> of first embodiment clamp assembly <NUM> (<FIG>), and thus is formed with opening <NUM> to enable a cam tube <NUM> of cam shaft assembly <NUM> to extend through the mounting bracket. Cam shaft assembly mounting bracket <NUM> is also formed with a plurality of slots <NUM> adjacent opening <NUM> to accept fasteners, such as bolts <NUM>, which are secured with nuts <NUM>, to enable the mounting of cam tube bracket <NUM> on the cam shaft assembly mounting bracket. In this manner, cam shaft assembly mounting bracket <NUM> enables the rigid attachment of cam shaft assembly <NUM> to inboard extension <NUM> of top axle seat <NUM>, thereby providing desired stability of the cam shaft assembly.

The operation of components of brake system <NUM> installed on integrated brake component mounting bracket <NUM> is similar to the operation described above for first embodiment clamp assembly <NUM> (<FIG>). As a result of the structural integration of cam shaft assembly mounting bracket <NUM> to front portion <NUM> of inboard extension <NUM> of top axle seat <NUM>, integrated brake component mounting bracket <NUM> provides rigid attachment of cam shaft assembly <NUM> to the top axle seat immediately inboard and adjacent each respective spring stack <NUM>, <NUM>, thereby providing desired stability and positioning of the cam shaft assembly. Likewise, as a result of the structural integration of air chamber mounting bracket <NUM> to rear portion <NUM> of inboard extension <NUM> of top axle seat <NUM>, integrated brake component mounting bracket <NUM> provides rigid attachment of brake chamber <NUM> to the top axle seat immediately inboard and adjacent each respective spring stack <NUM>, <NUM>, thereby providing desired stability and positioning of the brake chamber.

In this manner, integrated brake component mounting bracket <NUM> provides a structure that enables brake chamber <NUM> and cam shaft assembly <NUM> to be rigidly mounted on or adjacent each axle 120F, 120R, without welding a brake chamber bracket and/or a cam shaft assembly mounting bracket to the vehicle axle. By eliminating the welding of brackets to each axle 120F, 120R, integrated brake component mounting bracket <NUM> enables each axle to be less susceptible to possible damage, as described above. In addition, because integrated brake component mounting bracket <NUM> enables elimination of the welding of a brake chamber bracket and/or a cam shaft assembly mounting bracket to each axle 120F, 120R, each axle can be formed with a thinner wall, also as described above. Such reduction of the wall thickness of each axle 120F, 120R in turn desirably reduces the cost associated with manufacturing underslung axle/suspension system <NUM> employing integrated brake component mounting bracket <NUM>, as the amount of material used to manufacture each axle is reduced. Moreover, the reduction of the wall thickness of each axle 120F, 120R desirably reduces the cost to operate a vehicle that employs underslung axle/suspension system <NUM> with integrated brake component mounting bracket <NUM>, as axle weight is reduced, which in tum reduces vehicle fuel consumption and the resulting costs associated with operation of the vehicle.

Moreover, when the preferred configuration employing dowels <NUM> to provide positive mechanical engagement of bottom axle seat <NUM> and integrated brake component mounting bracket <NUM> with each respective axle 120F, 120R, welding of components to each axle is further reduced. More particularly, this positive mechanical engagement combines with the clamp action of U-bolts <NUM> and nuts <NUM> to secure bottom axle seat <NUM> and integrated brake component mounting bracket <NUM> to each respective axle 120F, 120R, thereby eliminating the need to weld the bottom axle seat and top axle seat <NUM> to each axle. Elimination of such welding enables axle 120F, 120R to be formed with a thinner wall when employing integrated brake component mounting bracket <NUM>, as compared to first embodiment clamp assembly <NUM>.

Such reduction of the wall thickness of each axle 120F, 120R in tum desirably reduces the cost associated with manufacturing an axle/suspension system using integrated brake component mounting bracket <NUM>, as the amount of material used to manufacture each axle is reduced. Moreover, the reduction of the wall thickness of each axle 120F, 120R desirably reduces the cost to operate a vehicle that employs an axle/suspension system with integrated brake component mounting bracket <NUM>, as axle weight is reduced, which reduces vehicle fuel consumption and the resulting costs associated with operation of the vehicle.

In this manner, integrated brake component mounting bracket of the present invention <NUM>, <NUM> provides a structure that enables brake chamber <NUM> and cam shaft assembly <NUM> to be rigidly mounted on or adjacent each axle 120F, 120R, without welding a brake chamber bracket and/or a cam shaft assembly mounting bracket to the vehicle axle. By eliminating the welding of such brackets to each axle 120F, 120R, integrated brake component mounting bracket of the present invention <NUM>, <NUM> enables each axle to be less susceptible to possible damage.

In addition, elimination of the welding of a brake chamber bracket and/or a cam shaft assembly mounting bracket to each axle 120F, 120R by integrated brake component mounting bracket <NUM>, <NUM> enables each axle to be formed with a thinner wall. Such reduction of the wall thickness of each axle 120F, 120R in tum desirably reduces the cost associated with manufacturing an axle/suspension system using integrated brake component mounting bracket <NUM>, <NUM> as the amount of material used to manufacture each axle is reduced. Moreover, the reduction of the wall thickness of each axle 120F, 120R desirably reduces the cost to operate a vehicle that employs an axle/suspension system with integrated brake component mounting bracket <NUM>, <NUM> as axle weight is reduced, which reduces vehicle fuel consumption and the resulting costs associated with operation of the vehicle.

Integrated brake component mounting bracket <NUM>, <NUM> employ mechanical attachment of top axle seat <NUM>, <NUM> and bottom axle seat <NUM>, <NUM> to each respective axle 120F, <NUM>, thereby reducing or eliminating the need to weld the top axle seat and the bottom axle seat to each axle. Reduction or elimination of such welding enables axle 120F, 120R to be formed with a thinner wall when employing integrated brake component mounting bracket <NUM>, <NUM> as compared to first embodiment clamp assembly <NUM>, further reducing axle cost and weight.

First and second embodiments clamp assemblies of the present invention enable the rigid attachment of air chamber mounting bracket <NUM> and cam shaft assembly mounting bracket <NUM> in alignment with bottom axle seat <NUM>, rather than being offset from the bottom axle seat. This structural alignment provides stability of air chamber mounting bracket <NUM> and cam shaft assembly mounting bracket <NUM>, which in turn enables brake chamber <NUM> and cam shaft assembly <NUM> to be rigidly mounted on or adjacent each axle 120F, 120R in a stable manner.

Integrated brake component mounting bracket <NUM> enables the rigid attachment of air chamber mounting bracket <NUM> and cam shaft assembly mounting bracket <NUM> immediately adjacent each respective spring stack <NUM>, <NUM> on an underslung axle/suspension system <NUM>. This structural positioning provides stability of air chamber mounting bracket <NUM> and cam shaft assembly mounting bracket <NUM>, which in tum enables brake· chamber <NUM> and cam shaft assembly <NUM> to be rigidly mounted on or adjacent each axle 120F, 120R in a stable manner within the space constraints imposed by underslung axle/suspension system <NUM>.

The present invention also includes a method of mounting a brake chamber and a cam shaft assembly to an integrated brake component mounting bracket, including steps in accordance with the description that is presented above and shown in <FIG>.

It is to be understood that the structure of the above-described integrated brake component mounting bracket of the present invention <NUM>, <NUM>, may be altered or rearranged, or certain components omitted or added, without affecting the overall concept or operation of the invention. As described above, it is also to be understood that the above-described integrated brake component mounting bracket of the present invention <NUM>, <NUM>, may be employed in conjunction with any type of spring axle/suspension system without affecting the overall concept or operation of the invention. For example, the invention applies to overslung and to underslung configurations of axle/suspension systems. In addition, the invention applies to various types of frames used for heavy-duty vehicles, including primary frames that do not support a subframe and primary frames and/or floor structures that do support a movable or non-movable subframe.

Accordingly, the improved integrated brake component mounting bracket is simplified, provides an effective, safe, inexpensive, and efficient structure which achieves all the enumerated objectives, provides for eliminating difficulties encountered with prior art brake component mounting brackets, and solves problems and obtains new results in the art.

In the foregoing description, certain terms have been used for brevity, clarity and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed. Moreover, the present invention has been described with reference to exemplary embodiments. It shall be understood that this illustration is by way of example and not by way of limitation, as the scope of the invention is not limited to the exact details shown or described. Potential modifications and alterations will occur to others upon a reading and understanding of this disclosure, and it is understood that the invention includes all such modifications and alterations and equivalents thereof.

Claim 1:
A clamp assembly (<NUM>) for a mechanical leaf spring axle/suspension system (<NUM>) of a heavy duty vehicle, the clamp assembly (<NUM>) for securing at least one leaf spring (<NUM>; <NUM>) of said mechanical leaf spring axle/suspension system (<NUM>) to an axle (<NUM>) thereof, wherein:
said clamp assembly (<NUM>) includes:
an upper plate (<NUM>) for disposal on an upper surface of said at least one leaf spring (<NUM>; <NUM>);
a top axle seat (<NUM>; <NUM>) for disposal between a lower surface of said at least one leaf spring (<NUM>; <NUM>) and an upper portion of said axle (<NUM>) in general vertical alignment with said upper plate (<NUM>);
a brake component mounting bracket (<NUM>; <NUM>); the brake component mounting bracket (<NUM>; <NUM>) including:
a bottom axle seat (<NUM>) for rigid connection to an axle (<NUM>) of said vehicle, said bottom axle seat (<NUM>) including a front portion (<NUM>) and a rear portion (<NUM>) and being configured to seat against a lower portion of said axle (<NUM>);
an air chamber mounting bracket (<NUM>) rigidly connected to said bottom axle seat (<NUM>) for rigid attachment of a brake air chamber (<NUM>) of a brake system thereto; and
a cam shaft assembly mounting bracket (<NUM>) rigidly connected to said bottom axle seat (<NUM>) for rigid mounting of a cam shaft assembly (<NUM>) of said brake system thereto; and
at least one U-bolt (<NUM>) for securing together said upper plate (<NUM>), said at least one leaf spring (<NUM>; <NUM>), said top axle seat (<NUM>; <NUM>), said axle (<NUM>), and said brake component mounting bracket (<NUM>; <NUM>); characterized in that
said brake component mounting bracket (<NUM>; <NUM>) is formed with bosses (<NUM>) that include openings for receiving respective ends of said at least one U-bolt (<NUM>); and
the brake component mounting bracket (<NUM>; <NUM>) for disposal on a lower portion of said axle (<NUM>) such as to be in general vertical alignment with said upper plate (<NUM>) and said top axle seat (<NUM>; <NUM>).