JPS6213836A - Self-adjusting parking brake - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved mechanical parking brake actuation assembly having integral self-adjusting characteristics and particularly suitable for rear axle disc brake assemblies.

The parking brake actuation assembly disclosed herein is a "bolt-on" type assembly intended for external mounting to disc brake calipers. This “Bolt・
When using the 'on' type assembly, the parking brake mechanism is not an integral part of the disc brake assembly;
Eliminates the need for disparate designs of front and rear axle disc brake assemblies.

The preferred embodiment of the "bolt-on" self-adjusting parking brake assembly includes an adjustable thrust screw non-adjustable nut combination mechanically actuated by a toggle bin for applying the parking brake. The adjusting nut is actuated by a ratchet pawl structure each time the thrust screw pre-adjusting nut is actuated. Whenever the parking brake is mechanically activated, or
Whenever the hydraulic brake is activated, the thrust screw non-adjustable nut combination is activated. Therefore, regardless of the frequency of use of the parking brake, by adjusting the parking brake mechanism,
Friction pad wear is prevented.

The embodiments described herein are preferably described in my Patent No. 4.
No. 391,355, such a floating force brake assembly is generally used. As shown in FIGS. , respectively, and a C-shaped floating caliper 10 having a brake pad assembly 16, 18'& a fixed inner leg 21 and an outer leg 22. Inner leg 21
It has a cylinder hole 12 whose longitudinal axis is approximately perpendicular to the axis of rotation of the disk 200 and in which a brake actuation piston 14 is slidably disposed.

In response to hydraulic actuation of the brake, piston 14 exerts a force on inner play V-pad assembly 16 to force the pad against disc 201. The stiff movement of the caliper 10 causes the outer caliper leg 22 to press the brake pad assembly 18 against the outer surface of the disc 20. As the hydraulic pressure increases in the silling hole 12, the caliper 10 pushes the brake pad assembly 16,1
As the clamping force applied to 8 increases, the braking torque also increases.

2, 4 and 8, the parking brake actuation and adjustment mechanism 24 is attached to the caliper 10 by suitable fastening means such as bolts 23 shown in FIG. 2I. Housing 32# has cross holes 34,36. The longitudinal axis of the hole 34 is substantially perpendicular to the plane of rotation of the disk 200, and
It is shaped to include a first diameter 29 extending from the inner end of the housing 32 and terminating in a shoulder 33 , and a second diameter 31 extending from the shoulder 33 to an outer shoulder 35 . The tapered hole 25 is located at the shoulder portion 3.
5 and terminates at the outer surface of the housing 32.

Put the head 54 on the shoulder 35! Toggle bin 52
is installed at the outer end of the hole 31 (through the circular hole 25).The mechanical actuation lever 26 is fixed to the outside of the toggle bin 52.

The actuator 26 has side arms 27a, 27b spaced apart by webs 30. These side arms include
] 1 includes six parts 28α and 28b that are inserted into the positioning holes 13α and 13b of the housing 32, respectively. Web 30 has
An opening 38 is provided for receiving the protruding toggle bin 52 therethrough. The toggle bin 52 and the actuating lever 26 are fastened together by a rough washer 43 that is received in the groove 55 of the pin 52, and the coil spring 15 is attached to the eye 57 of the pin 52 and the lever 2.
6 and the notch 41. Garbage hole 251
A dust pan 90 is provided to prevent dust from entering. By the action of washer 43 and barb 15, 6 parts 28α and 28
b is held in the positioning holes 13α and 13b, and the toggle pin head 54 is seated on the shoulder portion 35#.

An adjustment nut 42 having a coaxial threaded hole 44 therein passes through the nozzle hole 34 and is engaged with the hole 31. The adjustment nut 42 communicates with the toggle pin 52 through a protrusion 49f of the nut 42 that abuts a recess 561 in the toggle pin head 54.

Adjustment screw 58 is threaded into threaded hole 441 of adjustment nut 42 and has an overhang head 60 fixedly received in a cage 62 secured to inner brake pad assembly 16.
including.

A dust pan 72 is provided to prevent dirt and other impurities from entering the hole 291 of the housing 32.

Having described the parking brake actuation elements, the automatic adjustment elements will now be described.

5 that comes into contact with the shoulder portion 37! An adjustment mechanism base plate 76 is provided in the hole 36I73. This plate 76 is provided with a pivot post 78. Post 78 is shown formed of upset sheet metal and formed onto the post by insertion of roll pins or other means known in the art. As shown in FIG. 8α, the adjusting pawl 66 is assembled to the plate 76 so that the pivot post 78 extends through the dog leg 7 of the pawl 66 through the opening 84 in the plate 66.
6 of the plate 76 and the 6 portion of the pawl 66. 72, thereby pushing the adjusting leg 7o counterclockwise. The plate 76 is held at a predetermined position in the axial direction by the snap ring 8o, and rotation is prevented by the rotation prevention 6 part 75. Once positioned within hole 36, side surface 82 of plate 76 and ratchet I'i
The track arm 68 is shown in FIGS. 4, 5, and 7. It slides into track groove 48 of adjustment nut 42 as shown in FIG.

The present invention has two operational functions: Fourth, as a primary function, the mechanism operates as a mechanical parking brake actuator. Second, the mechanism has friction pads 16.17
It functions as a self-adjusting mechanism that prevents the parking brake from losing effectiveness due to wear. This self-adjusting mechanism has two unique modes of operation: first, and most importantly, the self-adjusting mechanism operates to adjust for brake pad wear that occurs during normal hydraulic braking operations; The adjustment mechanism is actuated by mechanical actuation of the parking brake.

Mechanical actuation of the parking brake is initiated by the vehicle operator applying tension to cable 98 by a parking brake mechanical actuation mechanism, not shown. The tension of the cable 98 causes the operating lever 26 to move into the hole 1 that receives the 6 part 28.
Rotate around 3. As the lever 26 rotates, the lever similarly rotates the toggle bin 52 as shown in FIG. Due to the rotation of the toggle pin 52, the adjusting screw 5
Adjustment nut 42 , threaded onto 8 , is moved axially to apply a braking action blade to inner brake pad assembly 16 .

The outer brake pad assembly 18 is brought into sliding contact with the disc 20 via a reaction force applied to the caliper 10. When the vehicle operator releases the parking brake mechanism (not shown), the actuation lever 26 and toggle pin 52 are returned to the normal idle position M by the return spring 15 (K as shown in FIG. 4).
E Return. The adjusting nut 42 in combination with the screw 58 returns to the mid-motion position under the action of the spring 88.

During normal hydraulic operation of the disc brake, the inner brake pad assembly 16i is engaged with the screw head 60 within a bracket 62 secured to the backing plate of the inner brake pad assembly 16 and adjusted with the adjustment nut 42. The screw 58 is similarly moved in the axial direction. Axial movement of the adjusting nut 42 toward the disc 20, either by actuation of the hydraulic brake or by the mechanical parking brake, causes a self-adjusting mechanism to move, causing the adjustment nut 42 to move in the direction of the amount of wear on the brake pads that requires adjustment. With constant axial displacement, adjusting pawl 66 rotates adjusting nut 42 to advance adjusting screw 58 by an amount proportional to the amount described below.

Referring primarily to FIGS. 5, 6, and 7, as the adjusting nut 42 is translated toward the disc 20, the leg 68 of the adjusting pawl 66 tracks within the groove 48 of the adjusting nut 42.
The pawl 66 is rotated about the pivot 78. Compare FIG. 5, which shows the mechanism in the brake released state, and FIG. 7, which shows the mechanism in the brake applied state. Since FIG. 7 shows the mechanical operation of the mechanism, the toggle bin 52 is shown in its tilted position, and when the adjusting nut 42 moves linearly by hydraulic punching, the toggle bin 52 moves as shown in FIG. It remains in its mid-motion position.

When the brake pad assembly 16.18 is in a state where wear control of the mechanical brake mechanism is desired, as evidenced by the predetermined adjustment screw translation, the pawl check feet 70 are arranged as shown in FIGS. 5 and 7. It is advanced by an adjusting screw ratchet wheel 47 that engages the next tooth as shown in the comparison.

Upon release of the brake application mechanism (parking brake or hydraulic brake), the energy stored in spring 88 acts during brake application to restore pawl 66 to its original position, thereby rotating adjustment nut 42 and proportionally adjusting adjustment screw 58. In addition to being advanced forward, the claw foot 68 acts on the adjustment screw groove 48 to return the adjustment screw 42 to its mid-motion position as shown in FIGS. 2 and 5.

Although the above description is of the preferred embodiments of the invention, it is contemplated that variations, changes and modifications may be made without departing from the scope or fair meaning of the claims.

[Brief explanation of drawings]

FIG. 1 is an exterior elevational view of a disc brake assembly suitable for use with the present mechanical parking brake, fJIJ
FIG. 2 is a side view of a floating caliper disc brake assembly as shown in FIG. 1 showing a "bolt-on" mechanical parking brake assembly as taught herein; FIG. Internal elevation of the disc shown,
FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 3 showing the actuation elements of the mechanical parking brake actuation assembly, and FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 6 is a sectional view taken along line 6-6 in FIG. 5, FIG. 7 is a sectional view similar to FIG. Figure 8a, an exploded view of the "bolt-on" mechanical parking brake assembly, shows the subassembly of the adjustable pawl mechanism. 10...Caliper, 11...Pin, 16.18...
・Brake pad, 15...Coil spring, 20...
Disc, 21, 22... Leg, 23... Bolt, 2
4... Parking brake operation and adjustment mechanism, 27...7-
4, 32... Housing, 42... Nut, 52.
...Toggle bin, 58...Screw, 66...Claw, 74
...Pivot hole, 78...Pivot column, 88...
Spring, 98...cable. Procedural amendment (method) August 2, 1985 Commissioner of the Patent Office Uga Michibu Dan 1, Indication of the case 1985 Patent Application No. 152608 2, Title of the invention Self-adjusting parking brake 3, Person making the amendment Case Relationship with Patent Applicant Name Kelsey Hayes Company 4 Agent 5 Engraving of the handwritten specification attached to the application subject to amendment 6 Contents of the amendment As shown in the attached sheet, however, there is no amendment to the content.

Claims (6)

[Claims] (1) In an automatically adjusting parking brake actuation mechanism used in a motor vehicle brake assembly, the mechanism is fixed to a friction pad means and moves in an axial direction in response to normal brake actuation movement of the friction pad means. thrust screw means; adjustment nut means having an axially threaded hole into which the thrust screw is screwed, the adjustment nut means including coaxial ratchet teeth and a circumferential groove circumscribing the adjustment nut means; Adjusting pawl means having a pivot, the pawl means including an adjusting leg communicating with the ratchet teeth and a cam leg communicating with the circumferential groove, wherein the pawl means is rotated by direct axial movement of the adjusting nut means. adjusting pawl means thereby rotating said ratchet teeth and said adjusting nut means relative to said thrust screw means; said adjustment in cooperation with said thrust screw means by applying an axial force to said adjusting nut means; and means for axially moving a nut means to place the friction pad means in a brake applying mode. (2) said means for applying an axial force to said adjusting nut means comprises toggle pin means in communication with said adjusting nut means, and rotation of said toggle pin means applies said axial force to said adjusting nut means; A mechanical parking brake actuation mechanism according to scope 1. (3) In cooperation with the automobile's hydraulically operated disc brake,
The automatically adjusting parking brake mechanism includes a housing juxtaposed to the disc brake assembly and having an elongated aperture therethrough, an elongated adjustment nut having a threaded aperture, and a thrust screw threadably received in the threaded aperture. a parking brake adjustment strut assembly, wherein the adjustment nut has a circumferential ratchet wheel and a circumferential groove that are axially separated from each other, and the strut assembly is slidably retained within the housing hole to thereby adjust the thrust screw; a parking brake adjustment strut assembly extending from a first open end of the housing bore; a means for securing the thrust screw to a friction pad assembly of one of the disc brakes; means for translational movement in cooperation with the friction pad assembly; pawl means movably secured to the housing, an adjustment leg communicating with the ratchet wheel and a cam leg communicating with the circumferential groove circumscribing the adjustment nut; and adjusting by linearly moving the adjustment strut assembly a predetermined length so that the pawl means adjustment leg rotates the ratchet wheel to advance the adjustment screw outwardly from the adjustment nut threaded hole. an automatically adjusting parking brake mechanism comprising pawl means for increasing the axial length of a strut assembly; and means for applying an axial force to the adjusting strut assembly to actuate the disc brake. (4) The means for applying an axial force to the adjustment strut assembly comprises toggle pin means communicating with the adjustment strut assembly, and rotation of the toggle pin means applies the axial force to the adjustment strut assembly. An automatically adjusting parking brake mechanism according to scope 3. (5) In an automatic brake adjustment device, an adjustment strut assembly including an adjustment nut means having a threaded hole and a thrust screw means threadedly received within the threaded hole, the adjustment nut means having a circumscribed ratchet wheel and an axle. an adjustment strut assembly having circumferential grooves separated from each other in a direction; means for securing said adjustment strut assembly to friction pad means of a brake assembly, said adjustment strut assembly being moved in cooperation with said friction pad means; securing means; pawl means including a first arm communicating with the ratchet wheel and a second arm communicating with the circumferential groove and having a pivot therebetween, the adjustment post assembly being in a predetermined axial alignment; Upon movement, the adjustment strut assembly rotates the adjustment strut assembly by rotating the pawl arm about the pivot to rotate the ratchet wheel and adjustment nut means relative to the thrust screw means. pawl means for changing the axial length of the automatic brake adjustment device. (6) In an automatic brake adjustment device, the adjustment strut means includes an adjustment nut means having a threaded hole and a thrust screw means for receiving a screw in the threaded hole, and is axially separated from the circumscribed ratchet wheel. an adjustment strut assembly having a circumferential groove; a means for securing said adjustment strut assembly to friction pad means of a brake assembly for moving said adjustment strut assembly in conjunction with said friction pad means; pawl means including a first arm in communication with the circumferential groove and a second arm communicating with the circumferential groove and having a pivot therebetween; and pawl means for rotating the ratchet wheel and the adjusting nut means relative to the thrust screw means to change the axial length of the adjusting nut assembly.