Automatic slack adjuster assembly

Abstract

A slack adjuster assembly comprises a housing (2) that receives a worm shaft (3) in a bore (a) of the housing (2) with a hex nut of the worm shaft (3) on the right side of the assembly. A worm wheel (16) is assembled in a hole (b) of the housing (2), and the worm wheel (16) meshes with the worm shaft (3). The hole (b) is perpendicular to the hole (a). The worm wheel (16) is inserted into the S-cam shaft, the S-cam shaft is coaxial with the hole (b) of the housing (2), the clutch worm wheel (4) is inserted into the hole (a) from the right side of the housing (2), the clutch worm wheel (4) is meshed with the sawteeth of the worm shaft (3), and the hole (c) is formed in the right side of the housing. A ratchet-pinion assembly (14) is inserted into the bore (c) of the housing (2), the clutch worm (14b) of the ratchet-pinion assembly (14) meshes with the clutch worm wheel (4), and the cover plate assembly (19) faces the brake chamber mounting bracket when the aforementioned slack adjuster assembly is mounted in the brake assembly.

Description

Technical Field

[0001] The present invention relates to an automatic slack adjuster. The improvement of the present invention lies in the design of the components and the sealing system. Background Art

[0002] General concept of self-setting automatic tensioner:

[0003] A Self-Setting Automatic Slack Adjuster (S-ASA) is used to maintain the clearance between the brake drum and the friction lining. In continuous braking applications, the clearance between the friction lining and the drum inner diameter increases due to wear. The Self-Setting Automatic Slack Adjuster is designed to adjust for this increased clearance. A controlled clearance between the lining and the drum is essential for effective braking performance. This clearance sensing and adjustment mechanism can be implemented in many designs. One such conventional design is described below.

[0004] Design introduction of conventional self-setting automatic tension adjuster

[0005] Figure 1 Brake assemblies 1L (left hand side) and 1R (right hand side) for drum brakes are shown. A self-setting automatic slack adjuster 1a is assembled to an S-camshaft 1b, and a brake chamber 1c is mounted to a bracket 1d. The self-setting automatic slack adjuster is connected to the brake chamber via a pin 1e, which is inserted into the brake chamber. Figure 2a The control arm 21 of the self-setting automatic slack adjuster 1a is anchored to a fixed member (not shown in the figure) of the vehicle.

[0006] The self-setting automatic slack adjuster has two sides, namely a front side and a rear side, which is shown in FIG. Figure 2a Indicates the front side of the self-setting automatic tensioner. Figure 2b Indicates the rear side of the self-setting automatic slack adjuster.

[0007] The rear side of the self-setting automatic slack adjuster 1a faces the bracket 1d when installed in the brake assembly 1L, and the front side of the self-setting automatic slack adjuster 1a faces the bracket 1d when installed in the brake assembly 1R.

[0008] Figure 2 Figure 3a and Figure 3b A conventional self-setting automatic slack adjuster assembly is shown, including a housing 2, which receives a worm shaft 3 in a hole a of the housing 2, wherein a hexagonal nut 3a of the worm shaft 3 is located on the left side of the assembly. A worm wheel 16 is assembled in a hole b of the housing 2 together with two O-rings 17 and 15, and the worm wheel 16 meshes with the worm shaft 3. A clutch worm wheel 4 having serrations is inserted into the hole b from the left side of the housing 2, and the clutch worm wheel meshes with the serrations of the worm shaft 3.

[0009] A hole c exists on the left side of the housing. The ratchet-pinion assembly 14 is inserted into the hole c of the housing 2, and the clutch worm 14a of the ratchet-pinion assembly 14 is meshed with the clutch worm wheel 4.

[0010] The front of the housing 2 is sealed by a gasket 18 and a cover assembly 19, as shown in FIG. Figure 1 As shown. Use seven M4 screws 20 to tighten the cover assembly to the housing.

[0011] The spring seat 9, the heavy coil compression spring 10 and the spring retainer 11 are inserted into the hole a of the housing 2 from the right end.

[0012] The bearing 5 is inserted into the hole a of the housing from the left side, as shown in Figure 2. The O-ring 6 is placed on the groove of the worm shaft 3, and then the bearing retainer 7 is inserted from the left side of the hole a.

[0013] A grease nozzle 12 is assembled to the housing 2. A protective cap 8 is assembled to the bearing retainer 7 at the left end of the hole a, which protects the self-setting automatic slack adjuster from water and dust. The protective cap 8 is anchored to the grease nozzle 12, which prevents the protective cap 8 from being lost during brake adjustment. Summary of the invention

[0014] Improvements in existing designs require:

[0015] 1. When using a conventional design, the same slack adjuster is used on both the left and right sides of the brake assembly. To achieve the desired function, the self-setting automatic slack adjuster 1a must be assembled to the camshaft in a specific direction, which is Figure 1 , where the left brake assembly 1L and the right brake assembly 1R use the same self-setting automatic slack adjuster 1a.

[0016] The self-setting automatic slack adjuster has two sides, namely a front side and a rear side, which is shown in FIG. Figure 2a Indicates the front side of the self-setting automatic tensioner. Figure 2b Indicates the rear side of a self-setting automatic slack adjuster. The front side of an assembly has more potential leak paths than the rear side of an assembly.

[0017] When based on Figure 1 When assembling the self-setting automatic slack adjuster, the front side of the brake assembly 1L is directly exposed to dust and water from the environment. This assembly condition increases the chance of mud and water entering the interior of the system, which may corrode the internal components, so the performance of the self-setting automatic slack adjuster 1a may be reduced.

[0018] 2. As shown in FIG4, when the worm shaft rotates in the "X" direction during assembly or maintenance, the pinion assembly 14 pushes the cover plate 19a in the direction indicated by the arrow "Y". The cover plate 19a screwed onto the housing 2 resists this force.

[0019] 3. Previously mentioned in point 1, the self-setting automatic slack adjuster 1a must be assembled in the brake assembly on the left and the brake assembly on the right from different directions. This assembly method is not ideal because it may create confusion in one's mind during assembly. The assembly method for both directions should be the same to avoid any kind of confusion.

[0020] 4. For Figure 1 In both brake assemblies 1L and 1R, the conventional design is installed from different directions, and the stress pattern in the self-setting automatic slack adjuster 1a will be different when installed in the assembly 1L on the left side compared to when installed in the assembly 1R on the right side. This results in different fatigue lives of the self-setting automatic slack adjuster 1a in the brake assemblies 1L and 1R. The same design having different fatigue lives when installed in the left and right camshafts does not represent an ideal state for the brake assembly.

[0021] Conventional designs have the above disadvantages, which are addressed by the present invention. The main purpose of the present invention is to improve the overall sealing capability of the self-setting automatic slack adjuster and to minimize potential leak paths. The objectives of the present invention are listed below.

[0022] Purpose of the Invention

[0023] 1. The objective is to design a self-setting automatic slack adjuster assembly that, when installed in a vehicle, has potential leakage areas that are not directly exposed to dust and water from the environment, thereby protecting the internal components from corrosion.

[0024] 2. The present invention is directed to designing a self-setting automatic slack adjuster assembly so that when the worm shaft is rotated (for brake resetting), the pinion assembly does not push the cover plate, thereby avoiding a potential leak path.

[0025] 3. The objective is to design a self-setting automatic slack adjuster assembly that can be assembled in the same orientation as conventional assemblies.

[0026] 4. The present invention is intended to provide a self-setting automatic slack adjuster assembly whose stress pattern will be the same as conventional designs and which will have a fatigue life similar to conventional assemblies.

[0027] 5. To achieve all of the above objectives, significant design changes would be required, but the present invention is intended to achieve these objectives with minimal design changes, which means that most of the internal components of the self-setting automatic tensioner will be used as is or with very minor changes in the new design. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1A conventional brake assembly is shown having:

[0029] Left brake assembly 1L;

[0030] Right brake assembly 1R;

[0031] Self-setting automatic tension adjuster 1a;

[0032] Camshafts 1b and 1g;

[0033] Brake chamber 1c;

[0034] Brake chamber mounting brackets 1d and 1h;

[0035] Pin 1e;

[0036] Cam tubes 1i and 1j.

[0037] Figure 2 Figure 3a and Figure 3b A conventional self-setting automatic slack adjuster 1a is shown, wherein:

[0038] Figure 2a Indicates the front side of the self-setting automatic tensioner;

[0039] Figure 2b Indicates the rear side of the self-setting automatic tensioner;

[0040] Subject 2;

[0041] Worm shaft 3;

[0042] Clutch worm gear 5;

[0043] Worm shaft O-ring 6;

[0044] Bearing retainer 7;

[0045] Protective cover 8;

[0046] Spring seat 9;

[0047] Heavy duty coil spring 10;

[0048] Spring retainer 11;

[0049] Grease injection nozzle 12;

[0050] Pinion spring 13;

[0051] Pinion assembly 14;

[0052] Worm gear O-rings 15 and 17;

[0053] Worm gear 16;

[0054] Gasket 18;

[0055] Cover plate subassembly 19;

[0056] Cover plate 19a;

[0057] Control arm 21;

[0058] Cover screws 20.

[0059] FIG. 4 shows a conventional self-setting automatic slack adjuster 1a, wherein:

[0060] Figure 4a shows the self-setting automatic slack adjuster along Figure 2a The section of line ZZ;

[0061] Figure 4b An enlarged view of section 4a is shown.

[0062] FIG5 shows a self-setting automatic tension adjuster of the present invention:

[0063] Figure 5a The front side of the self-setting automatic slack adjuster of the present invention is shown;

[0064] Figure 5b The rear side of the self-setting automatic slack adjuster of the present invention is shown. DETAILED DESCRIPTION

[0065] First the components of a conventional design will be explained, followed by its operating principles, and then the present invention and its operating principles will be explained.

[0066] Assembly of conventional design:

[0067] Figures 2 and 3 show a conventional self-setting automatic slack adjuster assembly, including a housing 2, which receives a worm shaft 3 in a hole a of the housing 2, wherein a hexagonal nut 3a of the worm shaft 3 is located on the left side of the assembly. A worm wheel 16 is assembled with two O-rings 17 and 15 in a hole b of the housing 2, and the worm wheel 16 is meshed with the worm shaft 3. A clutch worm wheel 4 having serrations is inserted into the hole a from the left side of the housing 2, and the clutch worm wheel is meshed with the serrations of the worm shaft 3.

[0068] A hole c exists on the left side of the housing. The ratchet-pinion assembly 14 is inserted into the hole c of the housing 2, and the clutch worm 14a of the ratchet-pinion assembly 14 is meshed with the clutch worm wheel 4.

[0069] The top of the housing 2 is sealed by a gasket 18 and a cover assembly 19, as shown in FIG2. The cover assembly is tightened to the housing using seven M4 screws 20.

[0070] The spring seat 9, the heavy helical compression spring 10 and the spring retainer 11 are inserted into the hole a of the housing 2 from the right end.

[0071] The bearing 5 is inserted into the hole a of the housing from the left side, as shown in Figure 2. The O-ring 6 is placed on the groove of the worm shaft 3, and then the bearing retainer 7 is inserted from the left side of the hole a.

[0072] The grease nozzle 12 is assembled to the housing 2. A protective cap 8 is mounted at the left end of the hole a, which protects the self-setting automatic slack adjuster from water and dust. The protective cap 8 is locked with the grease nozzle 12, and this locking prevents the protective cap 8 from falling off from the assembly.

[0073] Figure 1 Brake assemblies 1L and 1R for drum brakes are shown. A self-setting automatic slack adjuster 1a is assembled to an S-camshaft 1b, and a brake chamber 1c is mounted to an anchor bracket 1d. The self-setting automatic slack adjuster is connected to the brake chamber via a pin 1e, which is inserted into a hole h of the self-setting automatic slack adjuster 1a. A control arm 21 of the self-setting automatic slack adjuster 1a is fixed to the anchor bracket via a screw (not shown in the figure).

[0074] The self-setting automatic slack adjuster has two sides, namely a front side and a rear side, which is shown in FIG. Figure 2a Indicates the front side of the self-setting automatic tensioner. Figure 2b Indicates the rear side of the self-setting automatic slack adjuster.

[0075] When installed in the brake assembly 1L, the rear side of the self-setting automatic slack adjuster 1a faces the brake air chamber mounting bracket 1d, and when installed in the brake assembly 1R, the front side of the self-setting automatic slack adjuster 1a faces the mounting bracket 1d.

[0076] How the general design works:

[0077] When the brakes are applied, there are two possible situations:

[0078] 1. The clearance between the brake lining and the inner diameter of the drum is within the predetermined limits. In this case, no adjustment is required.

[0079] 2. The clearance between the brake lining and the inner diameter of the drum exceeds the predetermined limit. In this case, adjustment is required.

[0080] Both situations will be discussed one by one.

[0081] Case 1

[0082] The control arm of the self-setting automatic slack adjuster 1a is anchored to a fixed member of the vehicle (not shown in the figures).The control gear is assembled in such a way that there will be no relative rotational movement between the control arm and the control gear.

[0083] When the brake is applied, the self-setting automatic slack adjuster 1a moves along Figure 2a. The control arm is fixed, so the control gear does not rotate. The pinion 14a is meshed with the control gear 4, so the pinion 14a rotates due to the rotation of the self-setting automatic slack adjuster 1a.

[0084] Before the brake is applied, there is a preset gap between the pawl housing 14d and the control worm 14b. The preset gap is positioned by the torsion spring 14e. The preset gap maintains a predetermined gap between the brake lining and the brake drum.

[0085] When the slack adjuster rotates, the worm wheel rotates the camshaft, and the gap between the brake lining and the brake drum begins to decrease. When the pawl housing 14d rotates, the gap between the pawl housing 14d and the control worm 14b closes.

[0086] If the clearance between the brake lining and the inner diameter of the drum is within predetermined limits, the brake lining will contact the brake drum when the clearance between the pawl housing and the clutch worm 14b is closed. In this case, the self-setting automatic slack adjuster 1a will not perform an adjustment.

[0087] Case 2

[0088] If there is too much play between the brake lining and the brake drum, the brake lining will not contact the brake drum when the pawl housing and clutch worm clearance closes. The self-setting automatic slack adjuster will continue to rotate, and during further rotation, the ratchet mechanism in the pinion assembly 14 will slip and adopt a new position.

[0089] Sliding of ratchet mechanism

[0090] Figure 10 shows the ratchet mechanism. When there is too much play between the brake lining and the drum, the pinion 14a continues to rotate in the counterclockwise direction indicated by the arrow "X". Due to the friction between the clutch worm 14b and the clutch worm wheel 4, the clutch worm 14b will not rotate with the pinion 14a. This friction comes from the serrations of the clutch worm wheel 4 and the worm shaft 3. The rotation of the pinion 14a causes the pawl pin 14c to slide and engage in the new position.

[0091] When the brake lining begins to contact the brake drum, further rotation of the self-setting automatic slack adjuster will increase the reaction torque in the assembly, and this torque will cause the saw teeth between the worm shaft 3 and the clutch worm wheel 4 to disengage.

[0092] Now, when the saw teeth disengage, there is no longer friction to stop the clutch worm 14b, so it can now rotate freely. This free rotation of the clutch worm 14b is essential to prevent over adjustment.

[0093] Reverse travel

[0094] When the brake is released, Figure 2a The self-setting automatic slack adjuster in will begin to rotate in a clockwise direction. The pinion assembly will begin to rotate in a clockwise direction. Since the ratchet teeth do not allow slippage in this direction, the clutch worm 14b will now rotate with the pinion 14a. Further rotation of the self-setting automatic slack adjuster will cause the brake lining and drum to separate. When the brake lining is disengaged from the brake drum, the reaction force is no longer present and the teeth of the worm shaft 3 and the clutch worm wheel 4 reengage.

[0095] The friction between the clutch worm 14b and the clutch worm wheel 4 is now restored due to the serrations. Further rotation of the self-setting automatic slack adjuster will cause the pinion 14b to rotate in the clockwise direction, but the clutch worm will not rotate due to the restored friction. The pawl housing 14d continues to rotate, and the preset clearance between the pawl housing 14d and the clutch worm 14b will be restored. This preset clearance is essential for controlling the ideal running clearance between the brake drum and the brake lining.

[0096] Further rotation of the self-setting automatic slack adjuster will rotate the clutch worm 14b in the clockwise direction, which in turn rotates the clutch worm wheel 4. The clutch worm wheel 4 will rotate the worm shaft 3 through the saw teeth, and the worm shaft 3 will now rotate the worm wheel 16. The worm wheel 16 in turn rotates the camshafts 1b and 1g, and this rotation causes the excess clearance existing between the brake linings and the drum to be reduced.

[0097] The present invention:

[0098] Figure 5 and Figure 6 A self-setting automatic slack adjuster assembly is shown, which includes a housing 2, which receives a worm shaft 3 in a hole a of the housing 2, wherein the hexagonal nut of the worm shaft 3 is located on the right side of the assembly. A worm wheel 16 is assembled in a hole b of the housing 2, and the worm wheel 16 meshes with the worm shaft 3. A clutch worm wheel 4 is inserted into the hole b from the right side of the housing 2, and the clutch worm wheel 4 meshes with the serrations of the worm shaft 3.

[0099] A hole c exists on the right side of the housing. The ratchet-pinion assembly 14 is inserted into the hole c of the housing 2, and the clutch worm 14a of the ratchet-pinion assembly 14 is meshed with the clutch worm wheel 4.

[0100] The front of the housing 2 is sealed by a gasket 18 and a cover assembly 19, as shown in FIG. Fig. 9 As shown. Use seven M4 screws 20 to tighten the cover assembly to the housing.

[0101] Bearing 5 is inserted into housing hole a from the right side. Fig. 9 As shown. Place the O-ring 6 on the groove of the worm shaft 3, and then insert the bearing retainer 7 from the right side of the hole a.

[0102] The grease nozzle 12 is assembled to the housing 2. A protective cap 8 is mounted at the right end of the hole a, which protects the self-setting automatic slack adjuster from water and dust. The protective cap 8 is locked with the grease nozzle 12, and this locking prevents the protective cap 8 from falling off from the assembly.

[0103] It can be said that changing the assembly direction is enough to assemble the slack adjuster on the other side, but if someone wants to change the assembly direction of the components, he / she must change all the components appropriately, otherwise the slack adjuster will not work. In other words, the direction of all gear teeth must be reversed.

[0104] The novelty here is to design a housing so that even if the orientation of the assembly is changed, only minimal modifications are required in a few parts.

[0105] Figure 8 Brake assemblies 1L and 1R for drum brakes are shown. A conventional self-setting automatic slack adjuster 1a is assembled to an S-camshaft 1g, and a brake chamber 1c is mounted to an anchor bracket 1h. The self-setting automatic slack adjuster 1a is connected to the brake chamber 1c via a pin 1e, which is inserted into a hole h of the self-setting automatic slack adjuster 1a. A control arm 21 of the self-setting automatic slack adjuster 1a is fixed to the anchor bracket 1h by a screw.

[0106] The redesigned self-setting automatic slack adjuster 1f is assembled to the S camshaft 1b, and the brake chamber 1c is mounted to the brake chamber mounting bracket 1d. The self-setting automatic slack adjuster 1f is connected to the brake chamber 1c via a pin 1e, which is inserted into the hole h of the self-setting automatic slack adjuster 1f. The control arm 21 of the self-setting automatic slack adjuster 1f is fixed to the vehicle chassis through an anchor bracket (not shown in the figure).

[0107] The self-setting automatic slack adjuster 1f also has two sides, namely a front side and a rear side, which is shown in FIG. 5 , wherein Figure 5a Indicates the front side of the self-setting automatic tensioner 1f, Figure 5b Indicates the rear side of the self-setting automatic tensioner 1f.

[0108] When mounted in the brake assembly 1L, the front side of the automatic slack adjuster 1f is set to face the brake chamber mounting bracket 1d, while when mounted in the brake assembly 1R, the front side of the automatic slack adjuster 1a is set to face the brake chamber mounting bracket 1h.

[0109] In this case, only the rear sides of the self-setting automatic slack adjuster 1f and the self-setting automatic slack adjuster 1a are directly exposed to the environment. The front side, which has more potential leakage paths, is protected by the brake chamber mounting brackets 1d and 1h and the cam tubes 1i and 1j. This assembly state prevents water or dust from entering the self-setting automatic slack adjuster 1f, while Figure 1 The front side of the self-setting automatic slack adjuster 1a of the brake assembly 1L is directly exposed to the environment.

[0110] Working principle of the present invention:

[0111] When the brakes are applied, there are two possible situations:

[0112] 1. The clearance between the brake lining and the inner diameter of the drum is within the predetermined limits. In this case, no adjustment is required.

[0113] 2. The clearance between the brake lining and the inner diameter of the drum exceeds the predetermined limit. In this case, adjustment is required.

[0114] Both situations will be discussed one by one.

[0115] Case 1

[0116] Refer to Figure 5. Figure 6 , Figure 7 , Figure 8 , Fig. 9 and Figure 11.

[0117] exist Figure 8 In the embodiment of the invention, the control arm of the self-setting automatic slack adjuster 1f is anchored to a fixed member of the vehicle (not shown in the figure). The control gear is assembled in such a way that there will be no relative rotational movement between the control arm and the control gear.

[0118] When the brake is applied, the self-setting automatic tension adjuster 1f moves along Figure 5a 1f. The control arm 14a rotates in the direction of the arrow shown in . Because the control arm is fixed, the control gear does not rotate. The pinion 14a is meshed with the control gear 1, so the pinion 14a rotates due to the rotation of the self-setting automatic slack adjuster 1f.

[0119] Before the brake is applied, there is a preset gap between the pawl housing 14d and the control worm 14b. The gap is controlled by the torsion spring 14e. The gap maintains a predetermined gap between the brake lining and the brake drum.

[0120] When the slack adjuster rotates, the worm wheel rotates the camshaft and the gap between the brake pad and the drum begins to decrease. When the pawl housing 14d rotates, the gap between the pawl housing 14d and the control worm 14b closes.

[0121] If the clearance between the brake lining and the inner diameter of the drum is within predetermined limits, the brake lining will contact the brake drum when the clearance between the pawl housing and the clutch worm 14b is closed. In this case, the self-setting automatic slack adjuster 1f will not perform an adjustment.

[0122] Case 2

[0123] If there is too much play between the brake lining and the brake drum, the brake lining will not contact the brake drum when the clearance of the pawl housing and the clutch worm 14b is closed. The self-setting automatic slack adjuster will continue to rotate, and during further rotation, the ratchet mechanism in the pinion assembly 14 will slip and adopt a new position.

[0124] Sliding of ratchet mechanism

[0125] FIG11 shows a ratchet mechanism. When there is too much play between the brake pad and the drum, the pinion 14a continues to rotate in the clockwise direction as indicated by the arrow "X". The clutch worm 14b will not rotate with the pinion 14a due to the friction between the clutch worm 14b and the clutch worm wheel 4. The friction comes from the serrations of the clutch worm wheel 4 and the worm shaft 3. The rotation of the pinion 14a causes the pawl pin 14c to slide and engage in the new position.

[0126] When the brake lining begins to contact the brake drum, further rotation of the self-setting automatic slack adjuster 1f will increase the reaction torque in the assembly, and this reaction torque will cause the saw teeth between the worm shaft 3 and the clutch worm wheel 4 to disengage.

[0127] Now, when the saw teeth disengage, there is no longer friction to stop the clutch worm 14b, so it can now rotate freely. This free rotation of the clutch worm 14b is essential to prevent over adjustment.

[0128] Reverse travel

[0129] When the brake is released, Figure 5a The self-setting automatic slack adjuster in will begin to rotate in the counter-clockwise direction. The pinion assembly will also begin to rotate in the counter-clockwise direction. Since the ratchet teeth do not allow slippage in this direction, the clutch worm 14b will now rotate with the pinion 14a. Further rotation of the self-setting automatic slack adjuster will cause the brake lining and drum to separate. When the brake lining is disengaged from the brake drum, the reaction force is no longer present and the serrations of the worm shaft 3 and the clutch worm wheel 4 re-engage.

[0130] The friction between the clutch worm 14b and the clutch worm wheel 4 is now restored due to the serrations. Further rotation of the self-setting automatic slack adjuster will cause the pinion 14b to rotate in the counterclockwise direction, but the clutch worm will not rotate due to the restored friction. The pawl housing 14d continues to rotate, and the preset clearance between the pawl housing 14d and the clutch worm 14b will be restored. This preset clearance is essential for controlling the ideal running clearance between the brake drum and the brake lining.

[0131] Further rotation of the self-setting automatic slack adjuster will rotate the clutch worm 14b in the counterclockwise direction, which in turn rotates the clutch worm wheel 4. The clutch worm wheel 4 will rotate the worm shaft 3 through the saw teeth, and the worm shaft 3 will now rotate the worm wheel 16. The worm wheel 16 in turn rotates the camshafts 1b and 1g, and this rotation causes the excess clearance existing between the brake linings and the drum to be reduced.

[0132] The present invention has disclosed the following novel features, such as:

[0133] according to Figure 6 The self-setting automatic tensioner assembly,

[0134] a. It includes a housing 2, which receives a worm shaft 3 in a hole a of the housing 2, wherein the hexagonal nut of the worm shaft 3 is located on the right side of the assembly. A worm wheel 16 is assembled in a hole b of the housing 2, and the worm wheel 16 meshes with the worm shaft 3. The hole b is perpendicular to the hole a. The worm wheel 16 is inserted into the S-camshaft, wherein the S-camshaft is coaxial with the hole b of the housing.

[0135] b. The clutch worm wheel 4 is inserted into the hole a from the right side of the housing 2 , and the clutch worm wheel 4 meshes with the serrations of the worm shaft 3 .

[0136] c. A hole c exists on the right side of the housing. The ratchet-pinion assembly 14 is inserted into the hole c of the housing 2 , and the clutch worm 14 b of the ratchet-pinion assembly 14 meshes with the clutch worm wheel 4 .

[0137] d. When the slack adjuster is installed in the brake assembly, its cover plate assembly 19 faces the brake chamber mounting bracket, thus avoiding direct exposure to dust and water.

[0138] It also discloses a self-setting automatic slack adjuster assembly as described above.

[0139] a. Hole c exists on the right side of the housing. It is parallel to the worm gear hole b but not coaxial.

[0140] b. Hole c exists on the right side of the housing. It is perpendicular to the worm shaft hole a.

[0141] c. The ratchet pinion assembly 14 with a one-way locking mechanism is inserted into hole c.

[0142] d. A ratchet pinion assembly 14 wherein the one-way locking mechanism slides in a clockwise direction.

[0143] e. The ratchet pinion assembly 14, wherein the pinion assembly pushes the housing 2 when it is rotated for maintenance, such as Figure 7 shown.

[0144] The essential features which have been disclosed, described and illustrated in the present invention are:

[0145] In one aspect, the present invention is a self-setting automatic slack adjuster assembly connected to a brake chamber, which includes a housing 2 having a plurality of holes a, b and c, a grooved worm shaft 3 having a plurality of serrations is inserted into the hole a of the housing 2, a hexagonal nut of the worm shaft is arranged on the right side of the assembly, a worm wheel 16 is inserted into the hole b of the housing 2, the worm wheel 16 meshes with the worm shaft 3 mounted on the hole a, a clutch worm wheel 4 is also inserted into the hole b of the housing 2 from the right side of the assembly, and the worm wheel meshes with the serrations of the worm shaft 3, a ratchet pinion assembly 14 having a clutch worm 14a is inserted into the hole c positioned on the right side of the housing 2 and The worm 14a of the ratchet pinion 14 is meshed with the clutch worm wheel 4, the cover plate assembly 19 is fixedly screwed onto the front part of the housing 2 together with the sealing gasket 18, thereby sealing the front part of the housing, the bearing 5 is inserted into the housing hole a from the right side of the assembly, the O-ring 6 is placed on the groove of the worm shaft 3, thereby sealing the right side part of the housing, the bearing retainer 7 is inserted from the right side of the hole a, the grease nozzle 12 is assembled to the side of the housing 2, the protective cover 8 is installed at the right end of the hole a, thereby protecting the assembly from water and dust, and the protective cover 8 is positioned using the grease nozzle 12 to prevent misalignment of the cover 8.

[0146] A feature of the arrangement according to the invention is that the cover plate assembly 19 faces the brake chamber mounting bracket, so only the rear side of the assembly is exposed to an environment that attracts water and dust, unlike conventional assemblies where both sides are exposed to the environment.

[0147] On the other hand, the present invention also discloses that hole b is perpendicular to hole a, hole c is perpendicular to hole a, hole c on the right side of the housing is parallel to the worm gear hole b but not coaxial with the worm gear hole b, the worm gear 16 is inserted into the S-camshaft, wherein the S-camshaft is coaxial with hole b of the housing 2, and the ratchet pinion assembly 14 is a one-way locking mechanism and is inserted into hole c.

[0148] On the other hand, the present invention also discloses that the one-way locking mechanism slides only in the clockwise direction, and the ratchet pinion assembly 14 is adapted to push the housing 2 when manually rotated for maintenance.

[0149] The examples and embodiments provided are for the purpose of understanding only, and none of them should limit the scope of the present invention. All variations and modifications that occur to those skilled in the art are within the spirit and scope of the present invention.

Claims

1. A self-setting automatic lash adjuster assembly connected to a brake chamber, comprising: a. a housing (2) having a plurality of holes (a, b and c), b. a grooved worm shaft (3) having a plurality of saw teeth, the worm shaft (3) being inserted into the hole (a) of the housing (2), wherein the hexagonal nut of the worm shaft is arranged on the right side of the assembly, c. a worm wheel (16) inserted into the hole (b) of the housing (2), the worm wheel (16) meshing with the worm shaft (3) mounted on the hole (a), d. The clutch worm wheel (4) is also inserted into the hole (b) of the housing (2) from the right side of the assembly, and the worm wheel is meshed with the serrations of the worm shaft (3), e. a ratchet pinion assembly (14) having a clutch worm (14a), the ratchet pinion assembly (14) being inserted into a hole (c) positioned on the right side of the housing (2) and causing the worm (14a) of the ratchet pinion (14) to mesh with the clutch worm wheel (4), f. a cover plate assembly (19) which, together with a sealing gasket (18), is fixedly screwed onto the front of the housing (22) to seal the front of the housing, g. a bearing (5) which is inserted into the hole (a) of the housing from the right side of the assembly, h O-ring (6), which is placed on the groove of the worm shaft (3) to seal the right side of the housing, i. The bearing retainer (7) is inserted from the right side of the hole (a), j. A grease nozzle (12) mounted on the side of the housing (2), k. a protective cover (8) fitted to the right end of the hole (a) to protect the assembly from water and dust, and l. The protective cover (8) is positioned by a grease nozzle (12) to prevent the protective cover (8) from being dislocated. The arrangement is characterized in that the cover plate assembly (19) faces the brake chamber mounting bracket so that only the rear side of the assembly is exposed to an environment that attracts water and dust, unlike conventional assemblies where both sides are exposed to the environment.

2. The self-setting automatic slack adjuster assembly of claim 1, wherein the hole (b) is perpendicular to the hole (a).

3. The self-setting automatic slack adjuster assembly of claim 1, wherein the hole (c) is perpendicular to the hole (a).

4. The self-setting automatic slack adjuster assembly of claim 1, wherein the hole (c) on the right side of the housing is parallel to the worm gear hole (b) but not coaxial with the worm gear hole (b).

5. The self-setting automatic slack adjuster assembly according to claim 1, wherein the worm gear (16) is inserted onto an S-cam shaft, wherein the S-cam shaft is coaxial with the hole (b) of the housing (2).

6. The self-setting automatic slack adjuster assembly according to claim 1, wherein the ratchet pinion assembly (14) is a one-way locking mechanism and is inserted into the hole (c).

7. The self-setting automatic slack adjuster assembly of claim 6, wherein the one-way locking mechanism slides only in a clockwise direction.

8. A self-setting automatic slack adjuster assembly according to claims 6 and 7, wherein the ratchet pinion assembly (14) is adapted to push the housing (2) when manually rotated for servicing.

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