US1967412A - Brake - Google Patents

Description

July 24;*1934.

L. E. LA BRIE BRAKE `Filed sept. 6, 1928 f INVENToR.

fag sin: 6W

A TTORNEY Patented July 24, 1934 PATENT OFFICE BRAKE Ludger E. La Brie, South Bend, Ind., assignor to Bendix Brake Company, South Bend, Ind., a

corporation of Illinois Application September B. 1928, Serial No. 304,126 21 Claims. (Cl. 188-78) This invention relates to brakes, and is illustrated as embodied in an internal expanding automobile brake of the type having one part which anchors when the drum is turning in one I direction and a different part which anchors when the drum is turning in the other direction.

An important object of the invention is to improve the smoothness of operation of the brake, and to eliminate unbalanced forces and sudden l shifts of the anchorage, by an improved arrangement and construction of the parts. One important feature relates to arranging to have the brake-applying forces thrust against the shoes or their equivalents along lines passing substantially through the brake anchors, so that there is no tendency to shift the shoes on the anchors, preferably by rounding the shoe ends on arcs having theircenters substantially in the axes of the anchors.

Such rounded construction also makes possible the brake adjustment, through the expanding means at the lower part of the brake, without any shifting of the shoes on their anchors. The original set of the brake applying lever is also maintained by virtue of this construction, which construction is advantageously combined with a number of improvements in the shoes and in the anchorage meansmore fully described below. y

I prefer to apply the brake by means such as a lever-type applying device, embodying in itself substantial novelty, in such a manner that there is a greater thrust on the primary shoe (i. e. the one which is unanchored and which serves asa servoshoe when the car is moving forward) than on the normally-anchored or secondary shoe. Taken with the return spring connecting the shoes, this greater thrust on the primary shoe yieldingly holds the' secondary shoe against its anchor until the brake is applied to such an-extent that the drum friction takes control 'of the anchorage, and either continues to hold the secondary shoe anchored if the car is moving forward or reverses the anchorage if the car" is moving'backward. Thus there is no shifting of the anchorage at all in the ordinary case, with the car moving forward, while in the occasional case when the car is moving backward the shifting takes place relatively slowly and before the brake is fully applied, so that there is no disagreeable shock or noise.

In connection with these novel features, I find it advantageous to use an improved arrangement of the auxiliary return spring, inclining it at such an angle as to urge the shoes bodily against their anchors, preferably, however, in such a manner as to act about the secondary anchor pin as a fulcrum 'and through the floating shoe connection to uge the other shoe toward a novel stop which determines the positions of the shoes when the brake is released.

Other features of the invention relate to novel means holding the adjustable floating shoe connection, to a new and very rigid mounting for the brake anchors, and to other desirable details of construction which will be apparent from the following description of the illustrative embodiment shown in the accompanying drawing, in which:

Figure 1 is a vertical section through the brake, just inside the head of the brake drum, and showing the brake shoes in side elevation;

Figure 2 is a central vertical section through the brake, on the line 2 2 of Figure 1;

Figure 3 is a partial section through the brakeapplying means and through the brake anchorage;

Figure 4 is a partial section through the adinstable floating shoe connection, on the line 4--4 of Figure '1;

Figure 5 is a partial section on the line 5--5 of Figure l, showing one of the steady rests;

Figure is a partial section on the line 6-6 of Figure l, showing the novel shoe-positioning stop;

Figure 'l is a partial section on the line '1 -'l of Figure l. showing another steady rest; and

Fig. 8 is a section through a modified form of brake anchor.

The illustrated brake. includes a rotatable drum- 10 at the open side of which is' a support such as a backing plate 12, and within which is arranged the friction means of the brake. This friction means preferably includes a pair of novel interchangeable shoes 14 and 16 having transverse pivots 18 and 19 at their lower ends threaded to receive a right-and-left threaded rotatably-adjustable connection 20 having a central collar formed with radial openings to receive a tool such as a nail inserted through an opening 22 in the backing plate.

0n the side opposite the backing plate there is a retainer such as a stamping 24, forked at its opposite ends to straddle a groove at the end of the right-hand'plvot 18 and behind a U-shaped washer 26 seated in a groove in the end of the left-hand pivot 19. Stamping 24 has lugs 28 turned out at right angles toembrace the collar on connection 20, and is punched to form a pro jection 30 serving as a. pawl yieldingly interlocking with the radial tool openings in the collar of connection 20.

The backing plate 12 may be provided with rigidly-mounted steady rest pins 32 engaging the sides of the shoe webs. These pins are preferably positioned at or near a point 90 degrees remote from the brake applying cam giving, with the pin 18 and cam, a good three point support for each iioating shoe. A steady rest 34 may also be provided, which passes through an opening in shoe 14 and is provided at its end with a washer engaging the drum side of the shoe web and held by means such as a U-shaped Washer 36 snapped into a groove in the end of the rest.

Shoe 16 is provided with a novel eccentric stop 38, adjustably mounted in the backing plate and operable from outside the backing plate and having a stamped roller 40 engaging the inner face of the shoe rim. This roller is preferably retained in position by a plain washer 41 seated on a rabbeted portion in the shank of the stop, which washer is retained by a sheer riveted portion 43 of said shank. This stop may have a concentric steady rest portion 42 projecting through an opening in the shoe web, and having at its end a washer engaging the drum side of the shoe web and held by means such as one of the U-shaped snap Washers 36.

Shoe 16 is urged against the adjustable stop roller 40, when the brake is released, by means such as a novel auxiliary spring 44 inclined at such an angle as to act through the connection 20 to urge shoe 16 away from the drum.

'I'he angle of spring 44 is preferably such as to urge both shoes 14 and 16 bodily toward the upperA side of the drum, against novel anchor pivots 46 and 48 passing through elongated anchor openings 50 in the ends of the shoes. Anchors 46 and 48 are grooved adjacent their ends to form end flanges and collars 52 between which the shoe webs are embraced. The plain and U washer construction disclosed in Figure 7- may, however, be substituted in lieu of the integral end flange as illustrated in Figure 8 wherein the anchor 146 has a collar 152-and has at its end a plain washer held by a U-shaped washer 136. The larger portions of openings 50, nearest the ends of the shoes, are large enough to pass over the end flanges of anchors 46 and 48, whereas the narrower portions of these openings, which are held against the anchors when the brake is released by means such as a main return spring 54 tensioned between the shoes, are too small for the passage of the end flanges of the anchors. The inner edges of openings 50, which are held against the anchors by spring 44, extend substantially parallel to the direction of brake-applying movement of the shoe ends andare preferably approximately 15 degrees with the horizontal.

According to an important feature of the invention, the ends of the shoes or their equivalents are rounded on arcs having their centers adjacent the anchor ends of openings 50, i. e. substantially in the centers of the anchors 46 and 48 when the brake is released, for engagement with thrust members such as square blocks 56 pivotally mounted between stampings 58 forming a floating applying lever connected at its lower end by a pivot 60 to an arm 62 pressed on the attened end of a shaft 64. Shaft 64 terminates opposite the upper end of lever 58 and arm 62 extends downwardly beside and parallel to the lever 58, both the lever and arm extending at a sufficient angle to the vertical to permit efficient brake application with movement of the service pedal.

Shaft 64 is journaled in a bearing 68 fitting lin an enlarged opening in the backing plate and rigidly secured to a reinforcing plate 70 resting at against the outer face of the backing plate and having at its ends spaced openings alined with openings in the backing plate. On the inner side of the backing plate there is another reinforcing plate 72, resting against the inner face of the backing plate and having an opening sleeved on the shaft bearing 68. Anchor pivots 46 and 48 are pressed into openings in the ends of plate 72, to form studs projecting through the alined spaced openings in the backing plate and in plate 70 and receiving nuts 74 co-operating with collars 52 to clamp the two reinforcing plates 70 and 72 and the backing plate 12 together. Plate v70 with its integrally secured bearing 68 together constitute a sub-assembly unit, as does the plate 72 together with the anchor pins 46 and 48 pressed therein. The openings in the backing plate are preferably vertically elongated, permitting, with the enlarged opening for the bearing 68, a vertical adjustment of the two brake operating sub-assembly units upon initial installation thereof.

It will be seen that blocks 56 thrust radially against the rounded ends of shoes 14 and 16, on lines passing through the centers of the anchor pivots, so that there is no tendency to shift the shoes on the anchors. Also the thrust on shoe 14 is some two times greater than the thrust on shoe 16. shoe 14 being the primary shoe which acts as a servo shoe when the car is moving forward and shoe 16 being the secondary shoe which remains anchored when the car is moving forward. Thus the greater thrust on shoe 14 acts 110 through spring 48 to hold shoe 16 against its anchor 48 while shoe 14 is being forced against the drum in the preliminary state of applying the brake.

As soon as shoe 14 engages the drum, it is urged 115 by the drum friction in a counter-clockwise direction (if the car is moving forward) to apply shoe 16, which thus never leaves its anchorage during the normal operation of the brake. If the car is. moving backward, shoe 14 is urged clockwise 120 by the drum friction, to shift the anchorage to pivot 46, so that the shift takes place before the brake is fully applied. Moreover during the shifting the lower edge of opening 50 in shoe 14 rubs against anchor 46, thus retarding the shifting movement. As the shifting thus takes place relatively slowly and not under load, there is no shock or noise.

While one illustrative embodiment has been described in detail, it is not my intention to limit the scope of the invention to that particular embodiment, or otherwise than by the terms of the appended claims. The adjustable connection between the shoes and the arrangement and mounting of roller 40 or its equivalent are re- 13:. spectively claimed in my divisional applications Nos. 687,430 and 687,431, both filed August 30, 1933.

I claim:

1. A brake comprising, in combination, a friction device adapted to anchor adjacent either of its ends and having at each of said ends a rigid web with its end rounded in an arc lhaving its center approximately at the corresponding anchorage point and applying means thrusting against said rounded ends.

2. A brake comprising, in combination, a friction device adapted to anchor adjacent either of its ends and having at each of said ends a rigid web with its end rounded in an arc having its center approximately at the corresponding anchorage point and a floating applying device having portions thrusting radially against said rounded ends.

3. A brake shoe having adjacent its end an anchor opening, and having its end rounded on an arc having its center approximately at the anchor end of said opening.

4. A brake shoe having adjacent its end an elongated anchor opening, and having its end rounded on an arc having its center adjacent the end of said opening furthest from the end of the shoe.

5. A brake shoe having adjacent one end an elongated opening with a relatively wide portion nearest the shoe end and a narrower portion further from the shoe end, in combination with an anchor pivot having a retaining part over which the relatively wide portion of the opening can pass but too large to permit the passage of said narrower portion.

6. A4 brake shoe having adjacent one end an elongated opening with a relatively wide portion nearest the shoe end and a narrower portion further from the shoe end. and having its end rounded on an are with its center in said narrower portion of the opening.

"I. A brake shoe having adjacent its end an anchor opening, and having its end rounded on an arc having its center approximately at the anchor end of said opening, in combination with an applying device thrusting against the shoe radially of said arc.

8. A brake shoe having adjacent one end an elongated opening with a relatively wide portion nearest the shoe end and a narrower portion further from the shoe end, and having its end rounded on an arc with its center in said narrower portion of the opening, in combination with an applying device thrusting against the shoe radially of said are.

9. A` brake backing plate having reinforcing parts provided with a bearing for an operating shaft, in combination with a pair of anchor members on opposite sides of the bearing and securing the parts to the backing plate.

10. A brake backing plate having reinforcing parts provided with a bearing for an operating shaft, in combination with a pair of anchor members extending through the backing plate on opposite sides of the bearing and having collars on the inner side of the plate and nuts threaded on their ends and co-operating with the collars to clamp said parts to the backing plate.

11. A brake backing plate having a pair of spaced openings and a bearing opening between the spaced openings, in combination with a reinforcing member lying flat against the outer face oi the pla-te and provided with a shaft bearing rigidly mounted at its center and fitting within the bearing opening of the plate and having spaced openings alined 'with those in the plate, and another reinforcing member lying nat against the inner face of the plate and having a central opening fitting over said bearing, and having rigidly mounted at its ends studs projecting through the alined spaced openings in the plate and the first reinforcing member and securingthe two reinforcing members and the plate together.

12. vA lbrake backing plate having a pair of spaced openings and a bearing opening between the spaced openings, in combination with a reinforcing member lying flat against the outer face of the plate and provided with a shaft bearing rigidly mounted at its center and fitting within the bearing opening of the plate and having Vspaced openings alined with those in the plate,

`ings embracing said pivots and having ends formed on arcs with their centers substantially at the axes of said pivots when the brake is released, and applying means thrusting radially of said arcs against said ends.

14. A brake comprising, in combination, a drum, a pair of anchor pivots at one side of the druxn, floating friction means having elongated openings embracing said pivots and having ends formed on arcs with their centers substantially at the axes of said pivots when the brake is released, applying means thrusting radially of said arcs against said ends and acting with greater force on one of said ends than on the other, and a return spring connecting said ends and holding said other end yieldingly anchored while said one end is forced against the drum, until the drum friction acting on saidfriction means determines the anchorage of the brake.

15. A brake -.comprising, in combination, a drum. a pair of anchor pivots at one side of the drum, floating friction means having elongated openings embracing said pivots and having ends formed on arcs with their centers substantially at the axes of said pivots when the brake is released, and applying means thrusting radially of said arcs against said ends, the inner sides of said openings being approximately parallel to the direction of brake-applying movement of said ends.

16. A brake comprisings, in combination, a

drum, a pair of anchor pivots at one side of the drum. floating friction means having elongated openings embracing said pivots and having ends formed on arcs with their centers substantially at the axes of said pivots when the brake is released, applying means thrusting radially of said arcs against said ends, the inner sides of said openings being approximately parallel to the direction of brake-applying movement of said ends, togetherwith an auxiliary spring urging said inner sides of the openings against the anchor pivots.

17. A brake comprising a backing plate. connected floating shoes on said plate, anchorage means for the unconnected ends of said shoes, and a spring (44) connected at its ends respec tively to one shoe and to said plate and nearly paralleling a line joining the ends of said shoe and urging it toward the anchorage means.

18. A brake comprising a backing plate, connected floating shoes on said plate, anchorage means for the unconnected ends of said shoes, a retracting spring tensioned betweenvsaid shoes4 adjacent the anchorage means, and a spring (44) connected at its ends respectively to one shoe and to said plate and nearly paralleling a line joining the ends of said shoe and urging it toward the anchorage means.

19. A brake comprising a backing plate, connected oating shoes on said plate, anchorage means for the unconnected ends of said shoes, a retracting spring tensioned between said shoes 150 connected at its ends respectively to one shoe and to said plate and substantially paralleling a line joining the ends of said shoe and urging it toward the anchorage means, and an applying device including a floating lever having spaced thrust parts engaging said unconnected ends respectively.

20. A brake comprising a backing plate, connected oating arcuate shoes on said plate, anchorage means for the unconnected ends of said shoes, and a spring connected at its ends respectively to one shoe only and to said plate and arranged in chordal relation to the central portion of said shoe for urging it toward the anchorage means.

LUDGER E. LA BRIE.

Images