Torque-dependent sheared guide pin assembly for heavy vehicles

Abstract

A guide pin assembly (80) for use with a disc brake system of a heavy vehicle includes a hollow guide pin (82), a fastener (92), a separate torque separable shear adapter (94). The guide pin (82) mounts a component of the disc brake system. A fastener (92) is disposed at least partially through the guide pin (82) and engages another component of the disc brake system to attach the guide pin (82) to the other component. A shear adapter (94) is at least partially disposed within the guide pin (82) and removably attached to the fastener (92).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 439,634, filed on January 18, 2023. Technical Field

[0003] The present invention generally relates to the art of brake systems for heavy-duty vehicles. In particular, the present invention relates to brake systems for heavy-duty vehicles utilizing disc brakes. More particularly, the present invention relates to a guide pin assembly and a pilot or support adapter having a torque-dependent shear feature for use with disc brake systems of heavy-duty vehicles. The guide pin assembly allows for the use of commonly available low-profile tools and facilitates consistent torque, thereby eliminating complexity and errors during assembly. Background Art

[0004] The use of brake systems on heavy vehicles is well known. For the sake of clarity and convenience, reference to heavy vehicles should be understood to include trucks, tractor trailers or semi-trailers, trailers, etc. Common types of brake systems used on heavy vehicles generally include drum brake systems and disc brake systems.

[0005] Disc brake systems are typically incorporated into the axle / suspension system of heavy-duty vehicles. More specifically, the disc brake system includes a plurality of disc brake assemblies, each of which is operatively mounted on or adjacent a respective wheel-end assembly of the heavy-duty vehicle. Each wheel-end assembly is, in turn, rotatably mounted on a respective spindle, which is fixedly connected to one end of the heavy-duty vehicle's axle, as is well known. A pair of suspension assemblies connect the axle to members of the heavy-duty vehicle's frame or subframe, thereby forming the axle / suspension system. For those heavy-duty vehicles that support a subframe, the subframe may be immovable or movable, the latter of which is commonly referred to as a sliding box, sliding subframe, sliding chassis, auxiliary sliding frame, or bogie.

[0006] Each disc brake assembly typically includes a torque plate that supports a bracket, which in turn supports a caliper. The torque plate is rigidly connected to the axle of the axle / suspension system, at or near the wheel end of a heavy vehicle, by means such as welding. The bracket is typically attached to and supported by the torque plate using mechanical fasteners (e.g., bolts). The bracket is formed with a pair of threaded openings extending through the bracket and having corresponding counterbores formed around each of the threaded openings on the inner side of the bracket. As is well known, the caliper is slidably connected to the bracket using a guide pin assembly of the prior art. Specifically, a hollow guide pin extending inwardly is positioned within each counterbore of the bracket and attached to the bracket via a fastener that is partially disposed within the guide pin and engages with a corresponding threaded opening in the bracket. More specifically, the caliper is formed with a pair of holes with corresponding bushings press-fitted therein to receive the corresponding guide pins, thereby enabling the caliper to slidably engage the guide pins and permitting lateral movement of the caliper relative to the bracket.

[0007] The caliper is also formed with a bore for receiving one or more pistons and an opening for receiving an actuator. The actuator is typically a brake air chamber or chamber that is in fluid communication with a source of compressed air to activate movement of the one or more pistons via a sealed mechanical actuation mechanism. The sealed mechanical actuation mechanism amplifies the force between the air actuator and the one or more pistons. The caliper is also formed with an outboard lining seat positioned opposite the one or more pistons. A pair of opposing brake linings having friction material mounted on a backing plate are positioned in a carrier such that one lining is adjacent to the one or more pistons and the other lining is adjacent to the outboard lining seat.

[0008] Each disc brake assembly also includes a rotor having a disc portion, a mounting portion, and a sleeve integrally formed with and extending between the disc and mounting portions. The disc portion of the rotor is positioned between a pair of opposing brake pads such that the friction material of each pad faces a respective one of an inner and outer surface of the disc portion. The mounting portion is adapted to be mounted to a hub of a corresponding wheel end assembly via mechanical fasteners (e.g., bolts), thereby rigidly connecting the rotor to the hub. The hub, in turn, is rotatably mounted to a vehicle axle (wherein one or more wheel rims and tires are mounted to the hub), such that the rotor rotates about the axle of the heavy vehicle as the tires rotate.

[0009] The disc brake assembly can have an alternative configuration that does not utilize a bracket. In this configuration, the caliper is slidably connected directly to the torque plate via a prior art guide pin assembly. More specifically, the torque plate is formed with a pair of threaded openings extending through the torque plate. A corresponding counterbore is formed on the inner side of the torque plate surrounding each of the openings. A hollow guide pin extending inwardly is positioned within each counterbore and attached to the torque plate via a fastener partially disposed within the guide pin and engaging the threaded opening. The caliper is then mounted on the guide pins in a manner similar to that described above.

[0010] During operation, upon engagement of the disc brake assembly, compressed air flows into the brake chamber, causing the disc brake assembly to actuate. This causes one or more caliper pistons to extend in an outboard direction, thereby forcing the brake pads adjacent to the one or more pistons outboard against the inner surface of the disc portion of the rotor. The force exerted by the one or more pistons against the brake pads and the inner surface of the disc portion of the rotor causes the caliper to slide in an inboard direction along the guide pins of the prior art guide pin assembly, thereby forcing the brake pads adjacent to the outer lining seats against the outer surface of the disc portion. The abutting contact of the friction material of the brake pads with the disc portion of the rotor causes the wheels of the heavy vehicle to slow and / or stop. The torque plate reacts and resists the torque generated during braking and maintains proper alignment of the caliper to ensure optimal operation of the components of the disc brake assembly.

[0011] While existing guide pin assemblies perform well, they also have several drawbacks, deficiencies, and limitations. For example, during assembly or maintenance of the disc brake assembly, fasteners used in the existing guide pins must be tightened to a specific torque using large equipment to ensure proper operation of the disc brake assembly. Due to packaging constraints of the axle / suspension system and the disc brake assembly, the use of such large equipment during assembly and maintenance may be difficult or impossible and / or prone to error, potentially resulting in improper operation and / or shortened service life of the disc brake assembly components.

[0012] Some prior art guide pin assemblies have incorporated torque-based shearing technology into guide pin fasteners to facilitate the use of low-profile tools operating within the clearances restricted by disc brake assembly packaging. However, such prior art shear-based fasteners may still experience off-axis or out-of-plane torque, which may alter the torque at which the shear joint breaks and / or prevent it from breaking at the desired location, resulting in improperly torqued and / or improperly broken fasteners. This can affect the assembly and disassembly, operation, and / or service life of the disc brake assembly, thereby increasing maintenance and repair costs and heavy vehicle downtime. Furthermore, prior art shear-based fasteners are typically designed such that they typically require the use of one or more specialized tools. For example, prior art shear-based fasteners typically have a first interface that enables the fastener to be engaged by a specialized tool for installation and torqueing. Once the prior art shear-based fastener is sufficiently torqued and the shear joint breaks, a different interface remains, which can be engaged with the fastener using a different tool for adjustment, maintenance, and / or disassembly. The use of one or more specialized tools complicates assembly and maintenance of the guide pin assembly and increases cost and downtime for heavy vehicles.

[0013] Therefore, there is a need in the art for a guide pin assembly for heavy vehicles that allows the use of commonly available low-profile tools in tight clearance conditions and provides a pilot or support adapter for a torque-based shear interface, thereby eliminating complexity and error during assembly and facilitating consistent torque maintenance. Summary of the Invention

[0014] Objects of the present invention include providing a guide pin assembly for heavy vehicles that allows the use of commonly available low-profile tools in tight clearance conditions.

[0015] Another object of the present invention is to provide a guide pin assembly for heavy vehicles that includes a torque-shear interface with a pilot or support adapter, thereby eliminating complexity and error during assembly and facilitating consistent torque.

[0016] These objects and advantages are achieved by a guide pin assembly for use with a disc brake system for a heavy vehicle according to the present invention, the guide pin assembly comprising a hollow guide pin, a fastener, and a separate torque-disconnectable shear adapter. The guide pin mounts a component of the disc brake system. The fastener is disposed at least partially through the guide pin and engages with another component of the disc brake system to attach the guide pin to the other component. The shear adapter is disposed at least partially within the guide pin and is removably attached to the fastener. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The preferred embodiments of the invention, illustrating the best mode contemplated by the applicant for applying the principles of the present invention, are set forth in the following description and illustrated in the drawings, and are particularly pointed out and recited in the appended claims.

[0018] Figure 1 is a perspective view of a heavy vehicle axle / suspension system including a pair of air disc brake assemblies;

[0019] Figure 2 yes Figure 1 A partially exploded view of the disc brake assembly is shown;

[0020] Figure 3 yes Figure 1-2 a perspective view of a bracket of the disc brake assembly shown;

[0021] Figure 4 yes Figure 1-2 A partially exploded view of a portion of the disc brake assembly is shown illustrating components of a guide pin assembly of an exemplary embodiment for mounting a caliper to a carrier;

[0022] Figure 5 yes Figure 1-2 and 4 , a partial elevational view (partially in section) of a portion of the disc brake assembly illustrating a guide pin assembly of an exemplary embodiment for mounting the caliper to the bracket;

[0023] Figure 6 yes Figure 5 A perspective view of a shear adapter of a fastener subassembly of a guide pin assembly of an exemplary embodiment is shown.

[0024] Like reference numerals in the drawings indicate like parts. DETAILED DESCRIPTION

[0025] According to the present invention, the guide pin assembly 80 ( Figure 4-6 ) may be incorporated into any disc brake assembly, such as a disc brake assembly 15 mounted to an axle / suspension system 5 of a heavy vehicle (not shown). Figure 1-5 ).

[0026] The axle / suspension system 5 includes an axle 10 and a pair of beams 12. The axle 10 includes a central tube 11 and a pair of main shafts 13 ( Figure 2) (only one shown), the spindles are fixedly attached to opposite ends of the center tube by any suitable means (e.g., welding). Beams 12 are spaced along center tube 11 and rigidly attached thereto by any suitable means (e.g., welding). A pair of wheel-end assemblies 7 each include a hub 8 rotatably mounted on a respective spindle 13. Respective mirror-image disc brake assemblies 15 are located on laterally opposite sides of the axle / suspension system 5 and are attached to or adjacent to the respective wheel-end assemblies 7, as is well known. Because the disc brake assemblies 15 are mirror images of one another, and for the sake of clarity and brevity, only one of the disc brake assemblies will be described below.

[0027] Disc brake assembly 15 includes a rotor 20 that is removably attached to hub 8. Rotor 20 includes a radially extending mounting portion or flange 22, a radially extending disk portion 24, and an axially extending sleeve 26. Flange 22 is integrally formed with sleeve 26, which extends between and interconnects the flange and disk portion 24. Flange 22 is formed with a plurality of openings 23 that align with corresponding openings (not shown) formed in hub 8 and that collectively receive corresponding fasteners (not shown) to removably secure rotor 20 to the hub so that the rotor rotates therewith.

[0028] Disc brake assembly 15 also includes a torque plate 14, a bracket 30, and a caliper 60. Torque plate 14 is attached to axle 10 and adjacent beam 12. Specifically, torque plate 14 is formed with a hole 17 extending transversely therethrough. More specifically, center tube 11 of axle 10 is disposed through hole 17 such that torque plate 14 is positioned outboard of beam 12. Torque plate 14 is typically rigidly attached to center tube 11, such as by welding, along the interface between hole 17 and the center tube, as is well known. Torque plate 14 is also formed with a plurality of transversely extending openings 16 adjacent respective longitudinal ends of the torque plate.

[0029] The bracket 30 is formed with an inner portion 32 ( Figure 3), an outer portion 34, and a pair of integral bridge arms 36 extending between respective longitudinal ends of the inner and outer portions. Each of the inner and outer portions 32, 34 is formed with respective front and rear abutments 38, 39 for receiving and supporting a pair of opposing brake linings 40. Each brake lining 40 includes a high-friction material 44 mounted or attached to a backing plate 42. More specifically, each brake lining 40 is positioned between the respective front and rear abutments 38, 39 of the respective inner and outer portions 32, 34 of the bracket 30, such that the friction material 44 of the brake linings faces each other. The bracket 30 is also formed with a plurality of transversely extending openings 31 and a pair of transversely extending threaded openings 33. The openings 31 are formed in a symmetrical arrangement through the inner portion 32 of the bracket 30 and adjacent the longitudinal ends of the bracket. These openings align with the openings 16 of the torque plate 14 to enable removable attachment of the bracket to the torque plate. Specifically, the bracket 30 is mounted on and removably attached to the torque plate 14 using a plurality of fasteners 18 that are received through aligned openings 16, 31 of the torque plate and bracket, respectively. More specifically, the bracket 30 is at least partially positioned over and around the disc portion 24 of the rotor 20 and attached to the torque plate 14 such that the inner and outer portions 32, 34, and therefore the friction material 44 of the brake lining 40, are positioned adjacent the inner and outer sides of the disc portion, respectively. Threaded openings 33 are each formed through the inner portion 32 of the bracket 30 and are adjacent to and vertically offset from the opening 31. Each of the threaded openings 33 includes a corresponding counterbore 35 formed around the perimeter of the respective opening and extending partially inwardly into the inner portion 32 of the bracket 30.

[0030] Special References Figure 4The caliper 60 is integrally formed with an inner portion 62, an outer portion 64, and a pair of bridge arms 66 extending between the longitudinal ends of the inner and outer portions, as is well known. The outer portion 64 of the caliper 60 includes an inwardly facing pad seat 69 for contacting the back plate 42 of one of the brake pads 40 during actuation of the disc brake assembly 15. The inner portion 62 of the caliper 60 is formed with a pair of openings 67 for mounting an actuator or brake chamber 27 using a pair of nuts 28. The brake chamber 27 is in fluid communication with a compressed air source (not shown) from a heavy vehicle (not shown) for activating movement of one or more pistons (not shown). The inner portion 62 is also formed with one or more outwardly facing holes 68 for receiving the one or more pistons. The inner portion 62 also includes a pair of holes 63 longitudinally spaced apart from each other and extending through the inner portion. The holes 63 are formed so that they align with corresponding threaded openings 33 and counterbores 35 of the bracket 30, allowing the caliper 60 to be installed or removably attached to the bracket. Alternatively, it is also contemplated that in certain configurations of the disc brake assembly 15, the disc brake assembly does not include the carrier 30. In such configurations, the caliper 60 may be mounted on and slidably connected to the torque plate 14 in a manner similar to that described below.

[0031] More specifically, according to an important aspect of the present invention, the caliper 60 is slidably mounted on and connected to the bracket 30 via a guide pin assembly 80 of the exemplary embodiment. The guide pin assembly 80 includes a pair of hollow guide pins 82. The guide pins 82 are formed as generally tubular structures made of any suitable material, such as metal. Each guide pin 82 is at least partially positioned within and extends inwardly of a corresponding counterbore 35 of the inner portion 32 of the bracket 30. The guide pins 82 can have any suitable length and can also have different relative lengths and / or diameters to prevent potential binding and ensure proper travel and movement of the caliper 60 during braking, as is well known.

[0032] Guide pin assembly 80 also includes at least one pair of cylindrical or tubular bushings 84 disposed within bore 63 of caliper 60. Bushings 84 have an inner diameter or size (not shown) that is equal to or slightly larger than an outer diameter or size (not shown) of guide pins 82. Bushings 84 also have an outer diameter or size (not shown) that is equal to or slightly smaller than the inner diameter or size of bore 63 of caliper 60. Bushings 84 are disposed within bore 63 in an interference fit and receive corresponding guide pins 82, enabling the guide pins, and therefore caliper 60, to slide relative to the bushings and bracket 30, respectively.

[0033] According to another important aspect of the present invention, the guide pin assembly 80 according to the exemplary embodiment of the present invention includes a pair of fastener subassemblies 90 (only one shown) ( Figure 5). Each fastener subassembly 90 includes any suitable attachment structure or fastener 92 and a separate torque-detachable shear adapter 94. The fastener 92 can be any suitable fastener (e.g., a bolt) made of any suitable material (e.g., metal) and includes a threaded end 93 axially opposed to a head and / or a common tool interface 95 (e.g., a hex socket head). The fasteners 92 of the fastener subassembly 90 can removably attach the guide pins 82 to the bracket 30. More specifically, the fasteners 92 can be disposed within the corresponding guide pin 82 and extend at least partially through the corresponding guide pin to engage the corresponding threaded opening 33 of the bracket 30.

[0034] The shear adapter 94 can be removably attached to the fastener 92 at the fastener's interface 95. Specifically, the shear adapter 94 is generally cylindrical having an outboard end 96 and an axially opposed inboard end 97. More specifically, the outboard end 96 is suitably sized and comprises any suitable shape, such as a hexagon, to enable engagement between the interface 95 of the fastener 92 and the outboard end of the shear adapter 94. The outboard end 96 of the shear adapter 94 can be attached to the interface 95 of the fastener 92 using a suitable lightweight adhesive that breaks or ruptures when sufficient torque is applied to the fastener subassembly 90, thereby allowing the outboard end to separate from the interface, rendering the interface undamaged and accessible.

[0035] The shear adapter 94 also includes an axial length or dimension L having any suitable length sufficient to ensure clearance between the inboard end of the guide pin 82 and the inboard end 97, thereby ensuring accessibility of the inboard end 97. Furthermore, the axial dimension L can be any suitable length sufficient to ensure engagement between the outboard end 96 of the shear adapter 94 and the interface 95 of the fastener 92. More specifically, the axial dimension L can be in the range of approximately 2.00 inches to approximately 3.00 inches, more preferably in the range of approximately 2.30 inches to approximately 2.40 inches. The shear adapter 94 also includes an outer diameter or dimension that is generally smaller than the inner dimension of the guide pin 82. In particular, the outer dimension of the shear adapter 94 can be in the range of approximately 0.6 inches to approximately 1.2 inches, more preferably in the range of approximately 0.9 inches to approximately 1.0 inches. More specifically, the outer dimension of the shear adapter 94 can vary along the axial dimension L, such that the shear adapter can have a non-uniform profile with multiple, differently arranged outer dimensions. For example, the shear adapter 94 can have an outer dimension Da at the outboard end 96 that is sized to allow engagement between the outboard end and the interface 95 of the fastener 92, as described above. The shear adapter 94 can also have an outer dimension Db at the inboard end 97 that is less than, greater than, or equal to dimension Da and is specifically sized to allow engagement between the inboard end and a commonly available low-profile tool (not shown).

[0036] According to yet another important aspect of the present invention, the inboard end 97 of the shear adapter 94 allows for the use of commonly available tools during assembly and maintenance of the drum brake assembly 15. In particular, the inboard end 97 is generally formed axially opposite the outboard end 96 and can be customized to have any suitable shape or interface to allow engagement with the inboard end without the use of specialized tools. More specifically, the inboard end 97 of the shear adapter 94 can include a shape suitable for engagement with a socket wrench or other commonly available low-profile tool. As a result, assembly and maintenance of the bracket 30 or torque plate 14, caliper 60, and guide pin assembly 80 do not require the use of specialized equipment or tools, making assembly and maintenance relatively easy and less complicated.

[0037] According to an important aspect of the present invention, the inboard end 97 of the shear adapter 94 also includes a torque-dependent shearing feature. Specifically, the shear adapter 94 includes a neck 99 positioned axially adjacent the inboard end 97. More specifically, the neck 99 includes an outer diameter or dimension Dc that allows the neck to break or shear at a predetermined optimal torque for the fastener 92 to attach the guide pin 82 to the bracket 30 or torque plate 14. The outer dimension Dc may be in the range of about 0.25 inches to about 0.50 inches, more preferably in the range of about 0.35 inches to about 0.42 inches, thereby allowing the neck 99 to shear at a torque in the range of about 125 lb-ft to about 230 lb-ft, more specifically in the range of about 180 lb-ft to about 200 lb-ft. As a result, because the inboard end 97 shears off at the predetermined optimal torque, over-torquing of the fastener 92 is prevented, thereby ensuring that the guide pin 82 is attached to the bracket 30 or the torque plate 14 at the optimal torque, thereby reducing errors during assembly and maintenance of the disc brake assembly 15. Similarly, because the neck 99 does not break or shear off until the predetermined optimal torque is reached, the shear adapter 94 remains intact and serves as an indicator that the optimal torque has not yet been applied to the fastener 92, thereby preventing under-torquing of the fastener.

[0038] According to another important aspect of the present invention, the shear adapter 94 of the fastener subassembly 90 further includes a pilot region 98. The pilot region 98 can be formed as a generally cylindrical segment axially located midway along the shear adapter 94 between the outboard end 96 and the inboard end 97. It is also contemplated that the pilot region 98 can be located near either the outboard end 96 or the inboard end 97. The pilot region 98 of the shear adapter 94 ensures that consistent torque is applied to the fastener 92, thereby ensuring proper fracture of the neck 99. Specifically, the outer dimension Dp of the pilot region 98 can be greater than the outer dimension Dc of the neck 99 and equal to or slightly less than the inner diameter of the guide pin 82. More specifically, the outer dimension Dp can be in the range of about 0.6 inches to about 1.2 inches, and more preferably in the range of about 0.9 inches to about 1.0 inches. As a result, when the fastener subassembly 90 is positioned within the guide pin 82, the pilot region 98 can contact the inner surface of the guide pin, thereby providing support to the fastener subassembly (and in particular, the shear adapter 94) and ensuring that the fastener subassembly (and in particular, the shear adapter) remains centered within the guide pin, thereby minimizing or eliminating subassembly wobble. Thus, the shear adapter 94 of the fastener subassembly 90 reduces or eliminates off-axis torque applied to the fastener 92 during assembly and installation, thereby preventing the neck 99 of the shear adapter from improperly breaking or shearing, or preventing over-torque or under-torqueing of the fastener into the bracket 30 or torque plate 14.

[0039] During operation of a heavy-duty vehicle (not shown), when disc brake assembly 15 is engaged, compressed air flows to actuator 27, causing one or more pistons of caliper 60 to move outward. The one or more pistons force adjacent brake pads 40 against the inner side surface of disc portion 24 of rotor 20 in an outboard direction. The force of the one or more pistons acting on brake pads 40 is reacted by disc portion 24, causing caliper 60 to be pulled inward relative to carrier 30 or torque plate 14 along guide pin assemblies 80. More specifically, bushings 84 disposed within bores 63 of caliper 60 allow the caliper to slide along corresponding guide pins 82, causing brake pads 40 adjacent to lining seats 69 to contact the outer side surface of disc portion 24 of rotor 20. The abutting contact of brake pads 40 with the inner and outer side surfaces of disc portion 24 of rotor 20 slows and / or stops the heavy-duty vehicle and generates a force (e.g., torque) that acts on caliper 60 and carrier 30 or torque plate 14, and is resisted by the torque plate.

[0040] Thus, the guide pin assembly 80 according to an exemplary embodiment of the present invention provides a torque-shear fastener subassembly 90 having a shear adapter 94 for attaching the guide pin 82 to the bracket 30 or torque plate 14, thereby allowing the use of commonly available low-profile tools during assembly and maintenance of the disc brake assembly 15. The shear adapter 94 of the fastener subassembly 90 also provides a pilot area 98 that supports and centers the fastener subassembly within the guide pin 82, thereby ensuring proper breaking or shearing of the neck 99 at a predetermined optimal torque for attaching the fastener 92 to the bracket 30 or torque plate 14, thereby helping to maintain consistent torque and eliminating complexity and errors during assembly and maintenance.

[0041] It should be understood that the guide pin assembly 80 according to the exemplary embodiment of the present invention may be used in conjunction with axle / suspension systems, wheel end assemblies, and / or brake system components other than those shown and described above without affecting the overall concept or operation of the present invention. It should also be understood that the components of the guide pin assembly 80 (including the guide pin 82, bushing 84, and fastener subassembly 90) may be formed using any suitable method and from any suitable material or combination of materials without affecting the overall concept or operation of the present invention.

[0042] The present invention has been described with reference to specific exemplary embodiments. This description is intended to be illustrative only and not limiting. Potential modifications and variations will occur to others upon reading and understanding this disclosure, and it should be understood that the present invention includes all such modifications, variations, and equivalents. In the foregoing description, certain terms have been used for the sake of brevity, clarity, and understanding, but these terms should not be used to imply unnecessary limitations beyond the requirements of the prior art, as these terms are used for descriptive purposes and are intended to be broadly interpreted.

[0043] Therefore, the guide pin assembly of the present invention is simplified; provides an effective, safe, inexpensive and efficient structure and method that achieves all the listed purposes; eliminates the difficulties encountered by existing guide pin assemblies; solves the problems existing in the prior art and achieves new results.

[0044] The features, discoveries and principles of the invention have now been described; the use and installation of the guide pin assembly of the invention are set forth in the appended claims; the features of the construction, arrangement and method steps; and the advantageous, novel and useful results obtained, as well as the novel and useful structures, devices, elements, arrangements, processes, parts and combinations.

Claims

1. A guide pin assembly for use with a disc brake system of a heavy vehicle, the guide pin assembly comprising: a hollow guide pin for mounting components of the disc brake system; a fastener disposed at least partially through the guide pin and engaging another component of the disc brake system to attach the guide pin to the other component; as well as A discrete torque-separable shear adapter is at least partially disposed within the guide pin and removably attached to the fastener.

2. The guide pin assembly of claim 1 , wherein the shear adapter further comprises an inner end portion and an outer end portion axially opposite the inner end portion; The outboard end has a first shape that corresponds to and engages an interface of the fastener, the interface being shaped to receive a commonly used tool. 3 . The guide pin assembly of claim 2 , the inner end portion having a second shape corresponding to and engageable by a commonly used low-profile tool.

4. The guide pin assembly of claim 2, said outboard end being removably attached to said fastener by an adhesive.

5. The guide pin assembly of claim 1, the shear adapter further comprising an axial length and an outer dimension, the outer dimension varying along the axial length.

6. The guide pin assembly of claim 5, the axial length being in the range of 2.00 inches to 3.00 inches.

7. The guide pin assembly of claim 5, the axial length being in the range of 2.30 inches to 2.40 inches.

8. The guide pin assembly of claim 5, the shear adapter further comprising a pilot region, wherein the outer dimension of the pilot region is equal to or smaller than the inner diameter of the guide pin.

9. The guide pin assembly of claim 8, the outer dimension of the pilot region being in the range of 0.6 inches to 1.2 inches.

10. The guide pin assembly of claim 8, the outer dimension of the pilot region being in the range of 0.9 inches to 1.0 inches.

11. The guide pin assembly of claim 5, the shear adapter further comprising a neck, wherein: The outer dimensions of the neck are optimized to shear at a predetermined torque rating.

12. The guide pin assembly of claim 11, the outer dimension of the neck being in the range of 0.25 inches to 0.50 inches.

13. The guide pin assembly of claim 11, the outer dimension of the neck being in a range of 0.35 inches to 0.42 inches.

14. The guide pin assembly of claim 11, said outer dimensions of said neck being optimized to shear at a torque in the range of 125 lb-ft to 230 lb-ft.

15. The guide pin assembly of claim 11, said outer dimensions of said neck being optimized to shear at a torque in the range of 180 lb-ft to 200 lb-ft.

16. A guide pin assembly for use with a disc brake system of a heavy vehicle, the guide pin assembly comprising: a hollow guide pin for mounting components of the disc brake system; a fastener disposed at least partially through the guide pin and engaging another component of the disc brake system to attach the guide pin to the other component; as well as A separate torque-detachable shear adapter is at least partially disposed within the guide pin and removably attached to the fastener.

17. The guide pin assembly of claim 16, the shear adapter further comprising an inner end portion and an outer end portion axially opposite the inner end portion; The outboard end is formed to correspond to and engage an interface of the fastener, the interface being shaped to engage a commonly available tool.

18. The guide pin assembly of claim 17, the inboard end of the shear adapter being formed to correspond to and engage commonly available low-profile tools.

19. The guide pin assembly of claim 17 or 18, the outboard end of the shear adapter being removably attached to the fastener by adhesive.

20. The guide pin assembly of any one of claims 16 to 19, the shear adapter further comprising an axial length and an outer dimension, the outer dimension varying along the axial length.

21. The guide pin assembly of claim 20, the axial length of the shear adapter being in the range of 2.00 inches to 3.00 inches or 2.30 inches to 2.40 inches.

22. The guide pin assembly according to any one of claims 16 to 21, the shear adapter further comprising a pilot region, The outer dimension of the pilot region is equal to or smaller than the inner diameter of the guide pin.

23. The guide pin assembly of claim 22, the outer dimension of the pilot region being in the range of 0.6 inches to 1.2 inches or in the range of 0.9 inches to 1.0 inches.

24. The guide pin assembly according to any one of claims 16 to 23, the shear adapter further comprising a neck, in, The outer dimensions of the neck are optimized to shear at a predetermined torque rating.

25. The guide pin assembly of claim 24, the outer dimension of the neck being in the range of 0.25 inches to 0.50 inches or in the range of 0.35 inches to 0.42 inches.

26. The guide pin assembly of claim 24 or 25, the outer dimensions of the neck being optimized to shear at a torque in the range of 125 lb-ft to 230 lb-ft or 180 lb-ft to 200 lb-ft.

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