CLEARANCE ADJUSTER ASSEMBLY FOR DRUM BRAKE SYSTEMS.
Patent Information
- Authority / Receiving Office
- MX · MX
- Patent Type
- Patents
- Current Assignee / Owner
- HENDRICKSON USA LLC
- Filing Date
- 2023-01-31
- Publication Date
- 2026-05-19
Smart Images
Figure MX433763B0
Abstract
Description
CLEARANCE ADJUSTER ASSEMBLY FOR DRUM BRAKE SYSTEMS Cross-reference with related application This application claims the benefit of U.S. Provisional Patent Application No. 63 / 071,455, filed on August 28, 2020. Background of the Invention Field of Invention The present invention relates generally to braking systems for heavy-duty vehicles. In particular, the present invention relates to braking systems for heavy-duty vehicles using drum brakes. More specifically, the present invention relates to a slack adjuster assembly for a heavy-duty vehicle brake system that has a more robust rotational reference mechanism, allows for 360° sealing of the inner and outer sides of the slack adjuster, and creates a continuous path between a camshaft grease chamber and the slack adjuster to improve lubrication of the camshaft grooves, thereby increasing the service life and maintenance interval of the brake system. Background of the Invention The use of braking systems in heavy-duty vehicles is well known. For the sake of clarity and convenience, it is made MA / a / ZUZ J / UUl refers to a heavy-duty vehicle with the understanding that such reference includes trucks, tractor-trailers or semi-trailers, trailers and the like. Common types of brake systems for heavy-duty vehicles typically include disc brake systems and drum brake systems. Drum brake systems are generally incorporated into an axle / suspension system. Drum brake systems typically include a brake drum mounted on a wheel hub of a wheel end assembly rotatably mounted on an outer end of the axle. The brake drum typically includes a pair of brake shoes housed within the drum. Each brake shoe has a sacrificial, high-friction brake lining mounted on a metal backing plate or shoe table and held radially spaced from the inner braking surface of the brake drum. An S-shaped cam attached to the outer end of a camshaft in the drum brake system's camshaft assembly is engaged with a pair of rollers, each roller being connected to one end of a respective brake shoe. Drum brake systems also include a prior art slack adjuster assembly. Prior art slack adjuster assemblies typically include a slack adjuster attached to the internal splined end of the camshaft. The slack adjuster establishes a rotational reference point for an automatic adjustment mechanism. In particular, the prior art slack adjuster assembly normally includes a control arm operatively connected to the axle / suspension system by a reference reaction bolt to establish the rotational reference point, as is known.More specifically, the self-adjusting mechanism of the prior art slack adjuster assembly indexes the camshaft rotation from the rotational reference point to maintain a preset distance or gap between the brake lining of the brake shoes and the inner braking surface of the brake drum. This self-adjusting mechanism thus regulates the stroke and mechanical force required to engage the brake pads against the brake drum to slow or stop the heavy-duty vehicle. When a heavy-duty vehicle operator applies the vehicle's brakes, compressed air from an air supply source, such as a compressor and / or air tank, is delivered through air lines or ducts to a brake chamber. The brake chamber converts the air pressure into mechanical force and moves a pushrod. The pushrod, in turn, moves the slack adjuster of the prior art slack adjuster assembly, causing the camshaft and S-shaped cam to rotate, forcing the brake pads against the inner braking surface of the brake drum. This creates friction and slows or stops the heavy-duty vehicle. The prior art slack adjuster assembly indexes the camshaft rotation when the operator applies the brakes.Once the heavy-duty vehicle operator releases the brakes, the camshaft, and therefore the S-shaped cam, rotates backward, allowing the radially spaced relationship between the brake lining and the inner braking surface of the brake drums to be re-established. The slack adjuster rotates to a new position based on the indexed rotation of the camshaft, thus maintaining the preset clearance between the brake lining and the inner braking surface of the brake drum. Prior art clearance adjuster assemblies, while suitable for their intended purpose, have disadvantages, drawbacks, and potential limitations. For example, prior art clearance adjuster assemblies are typically not sealed along the inner side of the clearance adjuster that operatively receives and mates with the camshaft. As a result, moisture, corrosive agents, and / or debris can potentially infiltrate between the clearance adjuster and the camshaft, causing corrosion and oxidation of the cross-spliced teeth and / or other components, thus increasing maintenance. MA / a / zuzo / uun brake system and heavy-duty vehicle downtime. Prior art sealing structures, such as covers, faceplates, and the like, have not optimally addressed the problem of slack adjusters, particularly prior art slack adjuster assemblies of the type having control arms mounted with a reference reaction pin. Furthermore, during heavy-duty vehicle operation, axle / suspension system vibration can potentially cause wear between the control arm and the reference reaction pin. Wear between the control arm and the reference reaction pin can potentially allow additional rotation of the slack adjuster's self-adjusting mechanism.As a result, prior art slack adjuster assemblies may not properly or correctly index the camshaft rotation, which could lead to a longer stroke and require mechanical force to engage the liners against the brake drum, thus reducing the effectiveness of the braking system. Therefore, there is a need in the art for an improved clearance adjuster assembly that provides a more robust rotational reference mechanism and a 360° seal of the inner and outer sides of the clearance adjuster that allows for improved lubrication of the splined connection between the camshaft and the clearance adjuster and prevents the infiltration of water, contaminants, and other debris. Brief Description of the Invention Objectives of the present invention include providing a slack adjuster assembly having a more robust rotational reference mechanism. Another objective of the present invention is to provide a slack adjuster assembly having a 360-degree seal around the inner and outer sides of the slack adjuster. Another objective of the present invention is to provide a clearance adjuster assembly having a continuous grease path or route between a camshaft grease chamber and the clearance adjuster for lubricating the camshaft grooves or splines. These objectives and advantages are achieved through the slack adjuster assembly for use with a heavy-duty vehicle drum brake system. The slack adjuster assembly includes a slack adjuster, a cam tube assembly, and an interlock assembly. The interlock assembly is located on the outer side of the slack adjuster and connects the cam tube assembly to the slack adjuster. A component of the interlock assembly and a component of the cam tube assembly work together to form a rotational reference mechanism for indexing the slack adjuster's self-adjusting mechanism. Brief Description of the Various Views of the Drawings Exemplary embodiments of the present invention, illustrative of the best manner in which the applicant has envisioned applying the principles, are set forth in the following description, shown in the drawings, and indicated and set forth particularly and clearly in the appended claims. Figure 1 is a fragmentary elevation view, partially in section, of a slack adjuster assembly of an exemplary modality, according to the present invention, incorporated into a braking system; Figure 2 is an exploded perspective view of a portion of the slack adjuster assembly shown in Figure 1, showing the slack adjuster, interlock assembly, and external sealing assembly; Figure 3 is a fragmentary elevation, sectional view of another exemplary slack adjuster assembly, according to the present invention; Figure 4 is an exploded perspective view of a portion of the slack adjuster assembly shown in Figure 3, showing the slack adjuster, interlock assembly components, and the external sealing assembly; Figure 5 is a fragmented perspective view in an ordered exploded view of a portion of the adjuster assembly of MA / a / ZUZ J / UUl clearance shown in figures 3-4, which shows the internal sealing assembly, clearance adjuster, interlock assembly components and the external sealing assembly integrated into the braking system; Figure 6 is an elevation view of a portion of the slack adjuster assembly shown in Figures 3 to 5, showing the slack adjuster connected to components of the interlock assembly and the external sealing assembly; Figure 7 is a fragmentary elevation, cross-sectional view of the slack adjuster assembly of the exemplary modality shown in Figure 3, which shows the interlock assembly with an alternative anchor ring; Figure 8 is an exploded, fragmented perspective view of a portion of the slack adjuster assembly shown in Figure 7 with the alternative anchor ring, showing the internal sealing assembly, slack adjuster and interlock assembly components and the external sealing assembly integrated into the brake system; Figure 9 is a fragmentary, cross-sectional, bottom view of the slack adjuster assembly of the exemplary modality shown in Figure 3, showing the interlock assembly with an alternative anchor ring and an alternative cam tube support notch, and showing the internal sealing assembly with an alternative cap and iviA / a / zuz j / uui Figure 10 is an exploded perspective view of a portion of the slack adjuster assembly shown in Figure 9, which shows the internal sealing assembly with the alternative cover, the slack adjuster, interlock assembly components with the other alternative anchor ring and alternative cam tube support notch, and the external sealing assembly integrated into the brake system. Similar reference characters refer to similar parts from beginning to end. Description of the Preferred Option A slack adjuster assembly of an exemplary embodiment 280 (Figures 1-2), according to the present invention, can be incorporated into a braking system 272 (partially shown). The slack adjuster assembly 280 includes a slack adjuster 282 having a body 300 that is operatively connected to a push rod or stem (not shown) extending from an air brake chamber (not shown), as is known. The slack adjuster 282 is mounted and engaged with an internal splined end 284 of a camshaft 286. The camshaft 286 is rotatably mounted within and extends through a cam tube 288 of a cam tube assembly 274 by means of a bushing or sleeve assembly 289. An external end 292 of the camshaft 286 extends outward from the cam tube. 288 to allow an S-shaped cam 290 to engage with the brake shoes or linings (not shown), as is known. The cam tube 288 is mounted parallel to a shaft 220 of a heavy-duty vehicle (not shown) by means of a cam tube bracket 291 and a brake spider 246. More specifically, the cam tube bracket 291 is mounted using any suitable means, such as fasteners 250, to a beam side wall 293, but alternatively, it can be mounted on a separate bracket attached to the shaft 220. An inner end 294 of the cam tube 288 is disposed through the cam tube bracket 291, which applies a clamping force to the cam tube using a plurality of tabs 298 as the fasteners 250 are tightened, securing and preventing rotation or slippage of the cam tube. In addition, an outer end 296 of the cam tube 288 is arranged through the brake spider 246, which is mounted on the outer end of the shaft 220. According to an important aspect of the invention, the slack adjuster assembly 280 also includes an external sealing assembly 350 (Figure 2), an interlocking assembly 355 (Figure 2), and an internal sealing assembly 380. With particular reference to Figure 2, the external sealing assembly 350 includes a seal 352 and a cover plate 362. The seal 352 can be formed from any suitable material, but more preferably from a polymer, such as Mylar. The seal 352 can have an adhesive coating on one or both of its internal and external sides for bonding the seal to the slack adjuster body 300 and the cover plate 362, respectively. The cover plate 362 can be formed from any suitable material, such as metal, by any suitable method.Each of the body 300, seal 352 and cover plate 362 have a respective plurality of aligned openings 302, 354, 364 to receive a respective number of fasteners (not shown) to join the cover plate to the body and form a watertight seal between them. The external sealing assembly 350 also includes a flexible sleeve 378. The sleeve 378 is formed of any suitable material, such as an elastomer, and extends between the cover plate 362 and the cam tube 288. In particular, the sleeve 378 interfaces with or is tightly coupled to at least a portion of the cover plate 362 using any suitable means, such as an integrally molded connection, adhesive, and / or friction-fit connection, to provide an additional 360° seal and prevent the infiltration of water, corrosive agents, and debris or waste into the slack adjuster 282. Specifically, the sleeve 378 can be slidably and tightly fitted around the cam tube 288 and integrally molded onto the cover plate 362 such that the openings 364 are arranged MA / a / zuzo / uun inside the case. According to another important aspect of the present invention, the interlock assembly 355 interconnects the cam tube 288 with the slack adjuster 282, enabling the cam tube to provide a relatively more robust rotational reference apparatus for an automatic adjustment mechanism (not shown) of the slack adjuster than slack adjuster assemblies of the prior art, such as those employing control arms mounted on reference reaction pins. In particular, the interlock assembly 355 includes a control ring 356. More particularly, the control ring 356 has an inner portion 358, which includes a fine control gear (not shown) formed on the outer diameter of the inner portion. Alternatively, the inner portion 358 of the control ring 356 may have any other suitable feature, such as a groove, a notch, or a ratchet, as known.The control ring 356 also includes a plurality of teeth 360 arranged around an inner surface of the control ring in a circumferentially spaced arrangement, such that the teeth are separated by a corresponding plurality of spaces 361. The control ring 356 is disposed at least partially within the body 300 of the slack adjuster 282 and is retained by the cover plate 362. As a result, the control gear of the inner portion 358 is operatively engaged with an adjusting pinion 306 within the body 300. Alternatively, the inner portion 358, which has a groove, notch, or ratchet, can be operatively engaged with any other suitable mechanism or slack adjuster 282 interface, such as a rack and pinion assembly or a ratchet wheel, as known.Therefore, the control ring 356 cooperates with the appropriate mechanism or interface to operate the automatic adjustment mechanism of the slack adjuster 282. Furthermore, the interlocking assembly 355 includes a generally tubular anchor ring 366. The anchor ring 366 has an inner portion 368 and an outer portion 370. The inner portion 368 includes a plurality of tabs 372 formed on its outer surface in a circumferentially spaced arrangement. The tabs 372 correspond to spaces 361 formed between the teeth 360 on the inner surface of the control ring 356. More specifically, the inner portion 368 of the anchor ring 366 is slidably arranged within the control ring 356, such that the tabs 372 engage between or interlock with the teeth 360 and operatively connect the control ring. The outer portion 370 of the anchor ring 366 includes an inner surface 374.Surface 374 articulates with the outer surface of cam tube 288 to provide a watertight seal and prevent the infiltration of corrosive agents and debris. It is also contemplated that surface 374 may be coated with any suitable material, such as rubber, or may be chemically or mechanically coated or treated to provide a friction seal between the surface and cam tube 288 that prevents relative rotational movement between the cam tube and the anchor ring 366. The anchor ring 366 may also include a recess or dimple 376 formed on the outer surface of the outer portion 370, extending radially inward from the outer surface and deforming or protruding from the inner surface 374. The dimple 376 is mechanically connected to the cam tube 288. More specifically, the cam tube 288 may include a corresponding recess or dimple 276 (Figure 1) that receives and engages coincidentally with the dimple 376 of the outer portion 370 of the anchor ring 366. The mechanical connection between the dimples 276 and 376 provides a more secure connection and prevents relative rotation between the cam tube 288 and the anchor ring 366, respectively. As a result, the anchor ring 366 allows the cam tube 288 to act as a non-rotating anchor for the control ring 356, which is important for the proper operation of the self-adjusting mechanism of the slack adjuster 282.More specifically, the connection between the anchor ring 366 and the cam tube 288, included. MA / a / zuzo / uun dimples 276, 376, prevents vibration of the heavy-duty vehicle during operation from causing incorrect indexing of the camshaft rotation 286. Therefore, the anchor ring 366, cam tube 288 and dimples 376, 276, respectively, provide a relatively more robust rotation reference mechanism than prior art backlash adjustment assemblies, such as those employing control arms mounted on reference reaction pins. According to another important aspect of the present invention, the interlocking assembly 355 and the external sealing assembly 350 cooperate to operatively connect the cam tube 288 to the clearance adjuster 282 to form a continuous path or route for lubrication of the internal splined end 284 of the camshaft 286. In particular, the connections between the cam tube 288, anchor ring 366, control ring 356, and cover plate 362 described above form a continuous path that allows grease from the cam tube to move between the cam tube and adjuster 282 while preventing grease loss to the environment. The sleeve 378 is also arranged around the control ring 356, anchor ring 366 and at least a portion of the cam tube 288 to prevent grease loss and infiltration of water, corrosive agents and debris into the slack adjuster 282 and cam tube 288.Therefore, the cam tube 288 and the clearance adjuster assembly 280 form a continuous grease path or chamber between the cam tube and internal components of the clearance adjuster 282 that maintains a reservoir for lubricating the internal splined end 284 of the camshaft 286. According to yet another important aspect of the present invention, the internal sealing assembly 380 includes one or more washers 382 (Figure 1) (only one is shown) arranged around the internal splined end 284 of the camshaft 286. The washers 382 may be formed of any suitable material, such as steel, and arranged so that the washers are in contact with and operatively connectable to the inner side of the body 300 of the clearance adjuster 282. The washers 382 may have varying thicknesses to account for variations in the dimensions of other components arranged internally to the outer end 292 of the camshaft 286. The washers 382 limit the axial movement of the camshaft 286 to less than approximately 0.15 cm (0.060 in.), more preferably between approximately 0.025 cm (0.010 in.) and approximately 0.11 cm (0.11 in.).0.045 inches), reducing wear on and increasing the service life of, bearings 289 and cam tube seals 297 of the cam tube assembly 274. It is also contemplated that the washers 382 may be formed with one or more notches extending radially outward from the inner diameter to facilitate the passage of grease through the washer. A retaining ring. 384 engages operatively with a groove 285 formed in the internal splined end 284 of the camshaft 286 to secure the camshaft in the clearance adjuster 282 and prevent outward movement of the camshaft and, in turn, the splines of the camshaft from separating from the splines of the worm wheel 304 (Figure 2) of the clearance adjuster. The retaining ring 384 can also retain the washers 382 against the body 300 around the camshaft 286. Alternatively, the washers 382 can capture or retain an inner cover plate (not shown), similar to the cover plate 362, against the body 300. The internal sealing assembly 380 also includes an external cap 386. The cap 386 can be formed of any suitable material or combination of materials, such as rubber or metal. In particular, the cap 386 can include a metal or composite plate 388 attached by any suitable means to one or more tapered or truncated conical rings or gaskets 390 (only one is shown) extending from the plate. The cap 386 can be attached to the clearance adjuster 282 or camshaft 286 by any suitable means. More preferably, the cap 386 includes an opening (not shown) in the plate 388. The opening aligns with a corresponding opening 287 formed in the internal splined end 284 of the camshaft 286. A fastener (not shown) is passed through the opening in the plate 388 and is received in the MA / a / zuzo / uun opening 287 of the internal splined end 284, thereby securing the cover 386 to the camshaft 286. The gasket 390 generally forms an interface with the inner side of the body 300 or, alternatively, the inner cover plate of the clearance adjuster 282. More particularly, the gasket 390 can be spliced to, or fastened to, the inner side of the body 300 or, alternatively, the inner cover plate of the clearance adjuster 282 by any suitable means, such as adhesive. During assembly, the camshaft 286 can be arranged through the brake spider 246, beam sidewall 293 and cam tube support 291 in such a way that the S-shaped cam 290 is arranged outwards from the brake spider. Next, the cam tube 288 can be placed on the camshaft 286. The control ring 356 of the interlock assembly 355 and the seal 352 and cover plate 362 of the external sealing assembly 350 can be installed or attached to the body 300 of the clearance adjuster 282. Next, the anchor ring 366 and sleeve 378 can be placed around the camshaft 286, such that the anchor ring engages with the cam tube 288. Next, the clearance adjuster 282 can be arranged around and operatively connected to the internal splined end 284 of the camshaft 286. Next, the sleeve 378 can be slid inward into position against the MA / a / zuzo / uun body 300 of the clearance adjuster 282 or cover plate 362 to join or mechanically connect to the body or cover plate and create a 360° sealing structure on the outside of the clearance adjuster. Then, the internal sealing assembly 380 can be installed over the internal splined end 284 of the camshaft 286, creating a 360° sealing structure on the inside of the clearance adjuster. Next, grease is pumped into the cam tube 288 through a port (not shown) in the cam tube, filling the cam tube, clearance adjuster 282, and internal sealing assembly 380, in such a way that excess grease is purged from the interface between the internal sealing assembly and the body 300 of the clearance adjuster.Therefore, the continuous grease path or encapsulation formed between the camshaft 288 and the slack adjuster 282, along with the interlock assembly 355 and the external and internal sealing assemblies 350 and 380, respectively, prevents the infiltration of water, corrosive agents, and debris into the camshaft splines 286 and the slack adjuster, retaining ring 384, washer 382, and camshaft bearings 289. As a result, the slack adjuster 282 requires less maintenance and has a longer service life. Therefore, the slack adjuster assembly 280, according to the present invention, provides a mechanism for MA / a / ZUZ J / UUl rotation reference that is relatively more robust than prior art slack adjuster assemblies, such as those employing reference reaction bolt mounted control arms, by providing the interlock assembly 355 that uses the connection between anchor ring 366 and cam tube 288 with respective dimples 376, 276 to prevent heavy vehicle vibration from causing incorrect indexing of camshaft rotation 286 during heavy vehicle operation. In addition, the internal and external sealing assemblies 380, 350, respectively, provide a 360° seal on the respective internal and external sides of the clearance adjuster 282 and create a continuous path between the cam tube 288 and the clearance adjuster to lubricate the splines of the internal splined end 284 of the camshaft 286 and helical gear 304, also as bearings 289.The slack adjuster assembly 280 thus prevents friction and wear of the washer 382 and seals 297 and bearings 289 of the cam tube assembly 274, thereby increasing the maintenance interval and service life of the slack adjuster 282 and reducing downtime of heavy-duty vehicles. Another embodiment of the slack adjuster assembly 480 (Figures 3-10), according to the present invention, can be incorporated into the braking system 272 (Figure 1) (partially shown), described above. The slack adjuster assembly 480 includes a slack adjuster 482 having a body 500 that is mounted on and connects with the internal splined end 284 of the camshaft 286. According to an important aspect of the invention, the clearance adjuster assembly 480 includes an external sealing assembly 550 (Figure 4), an interlocking assembly 555 (Figure 4), and an internal sealing assembly 580. With particular reference to Figure 4, the external sealing assembly 550 includes a gasket or seal 552 and a cover plate 562. The seal 552 can be formed from any suitable material, but more preferably from a polymer, such as Mylar. The seal 552 can have an adhesive coating on one or both of its internal and external sides for bonding the seal to the body 500 and cover plate 562. The cover plate 562 can be formed from any suitable material, such as metal, by any suitable method.Each of the body 500, seal 552 and cover plate 562 have a respective plurality of aligned openings 502, 554, 564 to receive a respective number of fasteners (not shown) to join the cover plate to the body and form a watertight seal between them. According to another important aspect of the present invention, the interlock assembly 555 interconnects the cam tube 288 with the slack adjuster 482, allowing MA / a / zuzo / uun that the cam tube provides a relatively more robust rotational reference apparatus for a self-adjusting mechanism (not shown) of the slack adjuster than prior art slack adjuster assemblies, such as those employing control arms mounted on reference reaction pins. In particular, the interlock assembly 555 includes a control ring 556. The control ring 556 is generally tubular with a central opening 558. The control ring 556 includes an integrally formed fine control gear (not shown) formed on the outer surface of the control ring. Alternatively, the control ring 556 may have any other suitable feature, such as a groove or notch or a ratchet, as known. The control ring 556 includes a recess 560 (Figure 3) formed around the opening 558 and extending axially outward from the inner side of the control ring.The rebate 560 can be formed in a star-shaped, floral, or any other appropriate shape having lobes, petals, extensions, or the like arranged circumferentially around the opening 558. The interlocking assembly 555 also includes a tubular crimp ring 601 with a central opening 602. The crimp ring 601 has an inner portion 603 and an elongated outer portion 604. The inner portion 603 has an integrally formed flange 605 that extends radially outward. The flange 605 has a star-shaped or floral shape, or any other suitable shape having lobes, petals, extensions, or the like, corresponding to the shape of the recess 560 of the control ring 556. More specifically, the outer portion 604 of the setting ring 601 is disposed through the opening 558 of the control ring 556, such that the flange 605 of the inner portion 603 is disposed within the recess 560. As a result, the flange 605 engages or mechanically interacts with the recess 560 and control ring 556 to prevent relative rotation between the setting ring and the control ring. The control ring 556 and inner portion 603 of the crimp ring 601 are operatively retained within the body 500 of the slack adjuster 482 by the cover plate 562. The control gear of the control ring 556 is operatively engaged with an adjusting pinion 506 within the body 500. Alternatively, the control ring 556, which has a groove, notch, or ratchet, can be operatively engaged with any other suitable mechanism or interface of the slack adjuster 482, such as a rack and pinion assembly or ratchet wheel, as known. As a result, the control ring 556 cooperates with the suitable mechanism or interface to operate the self-adjusting mechanism of the slack adjuster 482. The interlock assembly 555 also includes a grounding ring 592. The grounding ring 592 is generally tubular with an opening 593. The opening 593 may be located off-center in the grounding ring 592. Alternatively, the opening 593 may be located centrally in the grounding ring 592. The opening 593 may be formed with a textured surface or have a plurality of integrally formed projections 598 arranged circumferentially around the opening and extending radially inward. The outer side of the grounding ring 592 is generally stepped or graduated, extending from the outer surface toward the opening 593.In particular, the grounding ring 592 can be formed with annular recesses 594, 595 that extend axially inwards from the outer side and are arranged radially in a staggered manner from the outer surface towards the opening 593. More particularly, the recess 595 extends axially inwards beyond the recess 594, providing a stepped appearance to the outer side of the grounding ring 592. The recess 595 of the grounding ring 592 allows the grounding ring and crimp ring 601 to be permanently connected by stamping. In particular, the outer portion 604 of the crimp ring 601 is disposed at least partially through the opening 593 of the grounding ring 592. More specifically, the grounding ring 592 is stamped onto the outer portion 604, such that the projections 598 of the opening 593 are forced to connect with and deform the outer portion of the crimp ring 601. The stamping of the grounding ring 592 to the crimp ring 601 forms a flange 607 (Figure 3) on the outer portion 604 of the crimp ring. The flange 607 extends radially outward from the outer portion 604 of the crimp ring 601 and the recess 595 of the grounding ring.As a result, the flange 607 can occupy the recess 595, such that the outer surface of the flange is coplanar with the outer surface of the recess 594. Stamping the grounding ring 592 to the crimp ring 601 can allow a small clearance or air gap 591 (Figure 7) to form between the grounding ring and the cover plate 562 to provide the clearance adjuster 482 with a predetermined amount of axial clearance. An annular groove 596 (Figure 5) is formed on the inner side of the grounding ring 592, extending axially outward, and corresponds to another annular groove 563 (Figure 4) formed on the outer side of the cover plate 562, which also extends axially inward. An O-ring 561 can be seated within and between annular grooves 596, 563 such that the O-ring can be compressed when the grounding ring 592 is stamped to the crimp ring 601.As a result, the 561 o-ring provides a. MA / a / ZUZ J / UUl seal between cover plate 562 and grounding ring 592, preventing grease loss and infiltration of water, contaminants and other road debris, while allowing relative rotation between cover plate and grounding ring during operation. The grounding ring 592 may also include a plurality of notches 597 formed on the outer surface of the grounding ring and extending radially inward. The notches 597 correspond to the plurality of aligned openings 502, 554, and 564 in the body 500 of the slack adjuster 482, seal 552, and cover plate 562, respectively, and facilitate access to the fasteners (not shown) arranged within the aligned openings. The grounding ring 592 also includes a projection or tab 600 (Figure 4) extending axially outward from the outer side of the grounding ring adjacent to the outer surface and between adjacent notches 597. Alternatively, the grounding ring 592 may have multiple tabs 600 in a circumferentially spaced arrangement, such that the tabs are located between adjacent notches 597.The tab 600 can also extend radially outward from the outer surface of the grounding ring, but it is preferably circumferentially coplanar with the outer surface. The tab 600 provides a more secure connection and prevents relative rotation between the grounding ring 592 and other components of the interlocking assembly 555, as described in more detail below. The interlocking assembly 555 also includes an anchor ring 566 (Figures 3, 5, and 7-8). The anchor ring 566 is generally tubular and has an inner portion 568 and an outer portion 570. The inner portion 568 has reduced dimensions compared to the outer portion 570. More specifically, the inner portion 568 has an outer diameter or dimension Di that is smaller than the outer diameter or dimension D2 of the outer portion 570. The inner portion 568 also has an inner diameter or dimension D3 that is smaller than the inner diameter or dimension D4 of the outer portion 570.The internal dimension D3 of the inner portion 568 allows the inner portion to be arranged around and connected to the inner end 294 of the cam tube 288 by any suitable means, such as a press fit, to prevent relative rotational movement between the cam tube and anchor ring 566 and to provide a tight seal, thereby preventing the infiltration of corrosive agents and debris. The inner portion 568 is arranged around the inner end 294 of the cam tube 288, such that the outer portion 570 is arranged around and radially spaced at a distance of at least one portion of the cam tube 288.Furthermore, the external dimension DI of the internal portion 568 allows the internal portion to be disposed at least partially within the grounding ring 592, such that the internal surface of the internal portion contacts the external surface of the recess 594 and / or the external surface of the flange 607. More preferably, the internal portion 568 of the anchoring ring 566 and grounding ring 592 are connected by a clearance fit, forming an air gap 567 between the grounding ring and the external portion 570. The air gap 567 provides an outlet for excess pressurized air and / or grease to which the cam tube 288 and clearance adjuster 482 may be exposed when the cam tube is greased using certain equipment, such as a pneumatic or high-pressure grease gun (not shown). The outer portion 570 of the anchor ring 566 may include a plurality of tabs 572 extending radially outward in a circumferentially spaced arrangement. The tabs 572 are generally arched or semicircular but may have any suitable shape. Each tab 572 has a notch 573 (Figure 5) formed adjacent to the radial end of the tab and shaped to receive a head of one of the respective fasteners 250. The fasteners may be slidably arranged within notches 573, such that the fasteners are MA / a / zuzo / uun are restricted and prevented from rotating, thereby facilitating the connection of the camshaft support 291 to the beam side wall 293. Furthermore, arranging the fasteners 250 within notches 573 prevents relative rotation between the anchor ring 566 and the beam side wall 293. More specifically, the press-fit connection between the inner portion 568 of the anchor ring 566 and the camshaft 288, a friction connection between the camshaft and the camshaft support 291, and the engagement of fasteners 250 with notches 573 prevent vibration of the heavy-duty vehicle during operation from causing incorrect indexing of the camshaft 286 rotation. Therefore, the anchor ring 566 with notches 573 provides a relatively more robust rotation reference mechanism than prior art backlash adjustment assemblies, such as those employing arms of control mounted on reference reaction pin. Alternatively, and with specific reference to Figures 7-8, the anchor ring 566 may include one or more circumferentially separated projections 772 (Figure 8) extending axially outward from the anchor ring. More preferably, the outer portion 570 may have a pair of projections 772 circumferentially separated by approximately 180° from each other. Each of the projections or projections 772 extends axially outward from the outer portion 570 by a distance Ll, such that at least one portion The projections 772 can be arranged between or connected with the tabs 298 of the cam tube support 291. More specifically, each of the projections 772 can be slidably arranged within a respective notch 299 formed between a respective pair of tabs 298 of the cam tube support 291. The arrangement of the projections 772 within respective notches 299 prevents relative rotation between the anchor ring 566 and the beam side wall 293. In particular, the press-fit connection between the inner portion 568 of the anchor ring 566 and the cam tube 288, the friction connection between the cam tube and the cam tube support 291, and the engagement of the projections 772 within notches 299 of the cam tube support 291 prevent vibration of the heavy-duty vehicle during the operation causes incorrect indexing of camshaft rotation 286.Therefore, the anchor ring 566 with projections 772 provides a relatively more robust rotational reference mechanism than prior art slack adjuster assemblies, such as those employing control arms mounted on reference reaction pins. Alternatively, and with specific reference to Figures 9-10, the anchor ring 566 may include a large projection or tab 972, best seen in Figure 10, extending axially outward from the anchor ring. Furthermore, the cam tube support 291 may be formed with at least one pair of adjacent tabs 498 shaped to provide an enlarged notch 499 (Figure 10) complementary to the tab 972. The tab 972 extends axially outward a distance L2 from the outer portion 570, such that at least a portion of the tab may be disposed between the adjacent tabs 498 of the cam tube support 291. More specifically, the tab 972 may be slidably disposed within the notch 499 formed between the adjacent tabs 498 of the cam tube support 291.The arrangement of the tab 972 within the notch 499 prevents relative rotation between the anchor ring 566 and the beam side wall 293. In particular, the press-fit connection between the inner portion 568 of the anchor ring 566 and the cam tube 288, the friction connection between the cam tube and the cam tube support 291, and the engagement of the tab 972 within the notch 499 of the cam tube support 291 prevent vibration of the heavy-duty vehicle during operation from causing incorrect indexing of the camshaft 286 rotation. Therefore, the anchor ring 566 with tab 972 and the cam tube support 491 with notch 499 provide a relatively more robust rotation reference mechanism than prior art backlash adjustment assemblies, such as those employing control arms mounted on a reference reaction pin. The outer portion 570 of the anchor ring 566 also includes one or more notches or recesses 576 (Figures 5, 8-10) (only one is shown) formed on the outer surface of the outer portion adjacent to the inner portion 568 and extending radially inward. It is also contemplated that, in the alternative configuration including the tab 972 described above, a single recess 576 may be formed, such that the recess aligns with and extends outward along the tab. The recesses 576 can be formed in such a way that the recesses are coplanar and continuous with the outer surface of the inner portion 568. The recesses 576 correspond to and receive respective tabs 600 of the grounding ring 592. The mechanical connection between tabs 600 and recesses 576 provides a more secure connection and prevents relative rotation between the grounding ring 592 and the anchoring ring 566.As a result, the cam tube 288, together with the friction connection between the cam tube and cam tube support 291, provides a robust, non-rotating reference or anchoring mechanism for the control ring 556, which is important for the proper operation of the self-adjusting mechanism of the slack adjuster 482. According to another important aspect of the present invention, the external sealing assembly 550 includes a ring MA / a / zuzo / uun of general tubular sealing 578. The sealing ring 578 is formed of any suitable material, such as an elastomer, and is disposed around the grounding ring 592 and at least part of the outer portion 570 of the anchoring ring 566. The sealing ring 578 provides an additional barrier that prevents grease loss and infiltration of water, corrosive agents, and debris into the slack adjuster 482 and cam tube 288 on the outer side of the slack adjuster. It is also contemplated that the sealing ring 578 may be joined to the grounding ring 592 using a retaining ring (not shown) and / or to the outer portion 570 of the anchoring ring 566 by means of a slip-fit or interference-fit connection.The interference-fit slip-fit connection between the sealing ring 578 and the outer portion 570 facilitates assembly while providing a bleed point in the outer sealing assembly 550 to allow grease to seep between the flange 600 and the recess 576. This prevents excessive grease pressurization during assembly and provides lubrication to protect the components from wear during operation. Alternatively, the sealing ring 578 can be joined to the grounding ring 592 and the outer portion 570 of the anchoring ring 566 using one or more retaining rings (not shown). It is also contemplated that the sealing ring 578 may include a hole opening. MA / a / zuzo / uun of pin (not shown) extending through the sealing ring and in fluid communication with the air space 567. In this configuration, the pinhole cooperates with the air space 567 to provide an outlet for excess pressurized air and / or grease to which the cam tube 288 and clearance adjuster 482 may be exposed when the cam tube is filled with grease using certain equipment, such as a pneumatic or high-pressure grease gun (not shown). According to another important aspect of the present invention, the interlocking assembly 555 cooperates with the external sealing assembly 550 to operatively connect the cam tube 288 to the clearance adjuster 482, forming a continuous path for lubrication of the internal splined end 284 of the camshaft 286. In particular, the connections between the cam tube 288, anchor ring 566, grounding ring 592, crimping ring 601, control ring 556, and cover plate 562, described above, form a continuous path that allows grease from the cam tube to move between the cam tube and the clearance adjuster 482, such that the grease can be purged between the respective splines or grooves of the internal splined end 284 of the camshaft 286 and the worm wheel 504 of the clearance adjuster.Therefore, the cam tube 288 and clearance adjuster assembly 480 form a continuous grease chamber or path between the cam tube and internal components of the clearance adjuster 482 that maintains a reservoir for lubricating the internal splined end 284 of the camshaft 286. According to another important aspect of the present invention, the internal sealing assembly 580 includes one or more washers 582 arranged around the inner splined end 284 of the camshaft 286. The washers 582 may be formed of any suitable material, such as steel, and arranged so that they are in contact with and can be operatively connected to the inner side of the body 500 of the slack adjuster 482. The washers 582 may have varying thicknesses to account for variations in the dimensions of other components arranged within the outer end 292 of the camshaft 286. The washers 582 limit the axial movement of the camshaft 286 to less than approximately 0.15 cm (0.060 in.), more preferably between approximately 0.025 cm (0.010 in.) and approximately 0.11 cm (0.045 in.), thereby reducing wear and increasing the service life of the bearings 289 and seals 297 of cam tube assembly 274.It is also contemplated that the washers 582 may be formed with one or more notches extending radially outward from the inner diameter to facilitate the passage of grease through the washer. A retaining ring 584 engages operatively in the groove 285 of the inner splined end 284 of the camshaft 286 to secure the camshaft in the slack adjuster 482, prevent outward movement of the camshaft, and in turn prevent the splines of the camshaft from separating from the splines of the worm wheel 504 within the slack adjuster. The retaining ring 584 may also retain the washers 582 against the body 500 around the camshaft 286. Alternatively, the washers 582 may capture or retain an inner cover plate (not shown), similar to the cover plate 562, against the body 500. The internal sealing assembly 580 also includes an external cover 586. The cover 586 may be formed of any suitable material or combination of materials, such as rubber, metal, or plastic. In particular, the cover 586 may include a metal or composite plate 588 attached by any suitable means to one or more O-ring, tapered, or truncated tapered seals 590 extending from the plate. The cover 586 may be attached to the clearance adjuster 482 and / or camshaft 286 by any suitable means. More preferably, the cap 586 includes an opening (not shown) in the plate 588. The opening aligns with opening 287 of the inner splined end 284 of the camshaft 286. A fastener (not shown) is passed through the opening in the plate 588 and received in opening 287 of the inner splined end 284, thereby securing the cap 586 to the camshaft 286. Alternatively, and with specific reference to the figures MA / a / zuzo / uun 9-10, the internal sealing assembly 580 may include a cap 786 similar in construction and arrangement to cap 586. The cap 786 may be formed of any suitable material or combination of materials, such as rubber, metal, or plastic. In particular, the cap 786 may include a metal or composite plate 788 attached to an annular or truncated conical seal 790. The plate 788 may include a circular base 781 and one or more integrally formed outward-extending flanges. The plate 788 may be disposed over the seal 790 such that the flange 783 is separated a radial distance outward from the seal. The flange 783 also extends outward from the base 781 a sufficient distance, such that the outer perimeter or edge of the flange can be adjacent to, in contact with and forming an interface with, connected or mechanically coupled to the body 500, protecting the seal 790 from impacts.The base 781 of plate 788 and seal 790 include aligned openings 789, 799, respectively, which correspond to and are aligned with opening 287 of the internal splined end 284 of the camshaft 286. A fastener (not shown) is passed through openings 789, 799 in plate 788 and seal 790, respectively, and is received in opening 287 of the internal splined end 284, thereby securing the cap 786 to the camshaft 286. MA / a / ZUZ J / UUl Seals 590, 790 generally form an interface with the inner side of the body 500 or, alternatively, the inner cover plate of the clearance adjuster 482. More specifically, seals 590, 790 can be spliced, mechanically connected, or attached to the inner side of the body 500 or, alternatively, the inner cover plate of the clearance adjuster 482 by any suitable means, such as adhesive. Seals 590 and 790 allow relative rotational movement between the cap 586 and 786, respectively, and the body 500 while maintaining a sliding seal during indexing of the camshaft 286. Therefore, the internal sealing assembly 580 with seals 590 and 790 and caps 586 and 786, respectively, prevents grease loss and infiltration of water, corrosive agents, and debris into the clearance adjuster 482 and cam tube 288 on the inner side of the clearance adjuster, while providing a bleed point for excess over-pressurized grease to escape.During assembly, the camshaft 286 can be arranged through the brake spider 246, beam side wall 293 and cam tube support 291, such that the S-shaped cam 290 is arranged outside the brake spider. Next, the cam tube 288 can be placed on the camshaft 286. A portion of the interlock assembly 555 and external sealing assembly 550 can be attached to the body 500 of the clearance adjuster 482. In particular, the crimp ring 601 can be slid through the opening 558 of the control ring 556, such that the flange 605 engages in the recess 560. The control ring 556 and crimp ring 601 can then be inserted into the clearance adjuster 482. The seal 552 and cover plate 562 can then be arranged around the crimp ring 601 and connected to the body 500 of the clearance adjuster 482.Next, the O-ring 561 and grounding ring 592 can be arranged around the outer portion 604 of the crimp ring 601. The grounding ring 592 can then be pressed onto the crimp ring 601, securely connecting the grounding ring to the crimp ring and forming the flange 607. The sealing ring 578 can be placed over and around the grounding ring 592. The anchoring ring 566 can be arranged on the camshaft 286 and around the inner end 294 of the cam tube 288 in a press-fit manner to connect the inner portion 568 of the anchoring ring to the cam tube.Next, the clearance adjuster 482 can be arranged around and operatively connected to the inner splined end 284 of the camshaft 286, such that the grounding ring 592 is arranged around the inner end 568 of the anchor ring 566 and such that the tab 600 of the grounding ring is arranged within the recess 576 of the outer end 570. Next, the sealing ring. 578 can be repositioned around the grounding ring 592 and a portion of the outer end 570 of the anchoring ring 566 and, alternatively, can be secured using one or more clamping rings. The internal sealing assembly 580 can be installed in and over the inner splined end 284 of the camshaft 286 to create, with the external sealing assembly 550, a 360° sealing structure on both the inner and outer sides of the clearance adjuster 482. Alternatively, the internal sealing assembly 580 can be installed in and over a portion of the inner side of the body 500 over the inner splined end 284 of the camshaft 286 to create a 360° sealing structure.The grease can then be forced into the cam tube 288 through a port (not shown) in the cam tube, filling the cam tube, slack adjuster 482, and internal sealing assembly 580, such that excess grease is purged from the interface between the internal sealing assembly and the slack adjuster body 500, between the grounding ring 592 and anchor ring 566 to the air gap 567, and / or between the sealing ring 578 and anchor ring 566. It is also contemplated that the grease can be purged through the air gap 567 and a small orifice opening (not shown) formed through the sealing ring 578.Therefore, the continuous grease path or encapsulation formed between the camshaft 288 and the slack adjuster 482, along with the interlock assembly 555 and the external and internal sealing assemblies 550 and 580, respectively, prevents the infiltration of water, corrosive agents, and debris into the camshaft splines 286 and the slack adjuster, retaining ring 584, washer 582, and camshaft bearings 289. As a result, the slack adjuster 482 requires less maintenance and has a longer service life. Next, the slack adjuster assembly 480, camshaft 286, and cam tube 288 can be mounted to the heavy-duty vehicle. Fasteners 250 can be inserted through the cam tube support 291. The cam tube support 291 can be slidably positioned around the S-shaped cam 290 and the outer end 296 of the cam tube 288. The cam tube support 291 can then be manipulated, such as by sliding, along the cam tube 288, until the heads of the fasteners 250 are arranged in notches 573 of tabs 572 of the anchor ring 566. Alternatively, the cam tube support 291 can be manipulated, such as by sliding, along the cam tube 288, until the projections 772, 972 of the outer portion 570 of the anchor ring 566 are arranged within notches 299, 499 between tabs 298, 498, respectively, of the cam tube support.Next, the S-shaped cam 290 and outer end 296 of the cam tube 288 can be arranged through the brake spider 246. Then, fasteners 250 can be arranged through the beam side wall 293 and tightened to secure the cam tube 288 within the cam tube bracket 291 and secure the bracket on the cam tube to the beam side wall to prevent rotation. Therefore, the clearance adjuster assembly 480, according to the present invention, provides a rotation reference mechanism that is relatively more robust than prior art clearance adjuster assemblies, such as those employing control arms mounted with a reference reaction pin, using an interlock assembly 555 with a press-fit connection between the anchor ring 566 and the cam tube 288, as well as the coupling between fasteners 250 and notches 573 or, alternatively, between projections 772, 972 and notches 299, 499 of the cam tube support 291, to prevent heavy-duty vehicle vibration from causing incorrect indexing of the camshaft 286 rotation.In addition, the slack adjuster assembly 480 with internal and external sealing assemblies 580, 550, respectively, provides a 360° seal on the internal and external sides of the slack adjuster 482, protects index reference components, and creates a continuous path or route between the cam tube 288 and the slack adjuster to lubricate the splines or grooves of the internal splined end 284 of the camshaft 286 and other components of the slack adjuster and braking system 272, thereby increasing the maintenance interval and service life of the slack adjuster and reducing downtime of the heavy-duty vehicle. It is contemplated that the slack adjuster assemblies 280 and 480 of the present invention may be formed from any suitable material, including, but not limited to, composite materials, metal, and the like, without altering the general concept or operation of the present invention. It is also contemplated that the slack adjuster assemblies 280 and 480 of the present invention may be used in braking systems on heavy-duty vehicles having more than one axle and / or one or more wheels per wheel end assembly, without altering the general concept or operation of the present invention. It is further contemplated that the slack adjuster assemblies 280 and 480 of the present invention may be used with all types of drum brake systems on heavy-duty vehicles without altering the overall concept or operation of the present invention. It is contemplated that different arrangements and materials of external sealing assemblies 350, 550; interlocking assemblies 355, 555; and internal sealing assemblies 380, 580, other than those shown and described, could be used without changing the general concept or operation of the present invention, provided they achieve a more robust rotational reference mechanism; a 360° seal on the inner and outer sides of the clearance adjusters 282, 482; and a continuous grease path between the cam tube 288 and the clearance adjuster. It is also contemplated that other methods and assembly sequences could be used for mounting the camshaft 286; cam tube 288; clearance adjusters 282, 482; and interlocking assemblies 355, 555. external sealing assemblies 350, 550 and internal sealing assemblies 380, 580 without changing the general concept or operation of the present invention. Consequently, the slack adjuster assemblies 280, 480 of the present invention are simplified; they provide an effective, safe, economical, and efficient structure and method, achieving all the enumerated objectives; they eliminate difficulties encountered with slack adjusters of the prior art and solve problems and yield new results in the art. In the preceding description, certain terms have been used for the sake of brevity, clarity, and understanding, but no unnecessary limitations beyond the requirements of the prior art are implied, since such terms are used for descriptive purposes and are intended to be interpreted broadly. Furthermore, the description and illustration of the invention are by way of example, and the scope of the invention is not limited to the exact details shown or described. Having now described the features, discoveries, and principles of the invention; the manner in which the slack adjuster assemblies are used and installed; the features of the construction, arrangement, and method steps; and the advantageous, novel, and useful results obtained, the new and useful structures, devices, elements, arrangements, processes, parts, and combinations are set forth in the appended claims.
Claims
1. A slack adjuster assembly for use with a drum brake system of heavy-duty vehicles, the slack adjuster assembly being characterized in that it comprises: a slack adjuster; a cam tube assembly and an interlock assembly, the interlock assembly being disposed on an external side of the slack adjuster and interconnecting the cam tube assembly with the slack adjuster; wherein a component of the interlock assembly and a component of the cam tube assembly cooperate to form a rotational reference mechanism for indexing an automatic adjustment mechanism of the slack adjuster.
2. The slack adjuster assembly of claim 1, characterized in that it further comprises an internal sealing assembly, the internal sealing assembly connecting to an inner side of the slack adjuster to form a 360-degree interface, and an external sealing assembly, the external sealing assembly connecting to the outer side of the slack adjuster to form a 360-degree interface.
3. The clearance adjuster assembly of claim 2, characterized in that the cam tube assembly component comprises a cam tube; wherein the interlock assembly component is at least partially arranged around the cam tube.
4. The clearance adjuster assembly of claim 3, characterized in that the cam tube, interlock assembly, and internal and external sealing assemblies cooperate to form a continuous grease path between the cam tube and the clearance adjuster.
5. The backlash adjuster assembly of claim 3, characterized in that the interlock assembly component has a dimple, the dimple being mechanically connected to a complementary recess formed in the cam tube to prevent relative rotation between the component and the cam tube.
6. The clearance adjuster assembly of claim 5, characterized in that the interlock assembly further comprises another component, the other component being retained at least partially within a clearance adjuster body and mechanically connected to the interlock assembly component and an automatic clearance adjuster adjustment mechanism.
7. The clearance adjuster assembly of claim 3, characterized in that the cam tube assembly further comprises a support having a plurality of fasteners, the cam tube being disposed through the support; wherein the interlock assembly component is connected to at least a portion of a respective one of the plurality of fasteners to prevent relative rotation between the cam tube assembly and the interlock assembly component.
8. The clearance adjuster assembly of claim 3, characterized in that the cam tube assembly further comprises a support having a plurality of notches, the cam tube being disposed through the support; wherein the interlock assembly component is connected to a respective one of the plurality of notches to prevent relative rotation between the cam tube assembly and the interlock assembly component.
9. A slack adjuster assembly for use with a heavy-duty vehicle drum brake system, the slack adjuster assembly being characterized in that it comprises: a slack adjuster; a cam tube assembly and an internal sealing assembly and an external sealing assembly; wherein the internal sealing assembly connects with an inner side of the slack adjuster to form a 360-degree interface and the external sealing assembly connects with an outer side of the slack adjuster to form a 360-degree interface.
10. The clearance adjuster assembly of claim 9, characterized in that it further comprises an interlock assembly, the interlock assembly interconnecting the cam tube assembly with the clearance adjuster to form a rotation reference mechanism for indexing an automatic adjustment mechanism of the clearance adjuster.
11. The clearance adjuster assembly of claim 10, characterized in that the cam tube assembly, the interlock assembly, and the internal and external sealing assemblies cooperate to form a continuous grease path or route between the cam tube assembly and the clearance adjuster.
12. The clearance adjuster assembly of claim 10, characterized in that the internal sealing assembly further comprises a cap having an outwardly extending seal.
13. The clearance adjuster assembly of claim 12, characterized in that the cover further comprises a plate, the plate extending radially outward from the seal and having an outwardly extending flange, the flange being radially separated from the seal and forming an interface 50 with the inner side of the clearance adjuster.
14. The slack adjuster assembly of claim 10, characterized in that the external sealing assembly comprises a flexible sleeve, the sleeve being outward from and forming an interface with the outer side of the slack adjuster; wherein the sleeve is disposed around at least a portion of the interlock assembly.
15. The clearance adjuster assembly of claim 14, characterized in that the external sealing assembly further comprises a cover plate, the cover plate also comprising the outer side of the clearance adjuster and a seal, the seal being connected between the clearance adjuster and the cover plate.
16. The clearance adjuster assembly of claim 15, characterized in that the sleeve forms an interface with the cover plate.
17. A slack adjuster assembly for use with a heavy-duty vehicle drum brake system, the slack adjuster assembly being characterized in that it comprises: a slack adjuster; a cam tube assembly and means for forming a continuous grease path or route between the cam tube assembly and the slack adjuster.
18. The clearance adjuster assembly of claim 17, characterized in that the cam tube assembly further comprises a cam tube.
19. The clearance adjuster assembly of claim 18, characterized in that the means further comprise an interlock assembly, the interlock assembly interconnecting the cam tube assembly with the clearance adjuster to form a rotation reference mechanism for indexing an automatic adjustment mechanism of the clearance adjuster.
20. The slack adjuster assembly of claim 19, characterized in that the means further comprise an internal sealing assembly, the internal sealing assembly being connected to an inner side of the slack adjuster to form a 360-degree interface.
21. The clearance adjuster assembly of claim 20, characterized in that the means further comprise an external sealing assembly, the external sealing assembly being connected to the outer side of the MA / a / zuzo / uun clearance adjuster to form a 360-degree interface.