US2284485A - Brake shoe - Google Patents

Description

May 26 1942- w. H. FARR ETAL 2,284,485

BRAKE SHOE Filed Aug. s, 1940 ATTORNEY Patented May 26, 1942 BRAKE SHOE Warren H. Farr, Carolus L. Eksergian, and Karl C. Earle, Detroit, Mich., assignors to Budd l `Wheel. Company, Philadelphia, Pa., a corporation of Pennsylvania Application August 3, V1940, Serial No. 350,880 4 claims. (ci. 18s-250i The invention relates to brake shoes, and more particularly to generally T-section form, such 'shoes fabricated out of lwrought or sheet metal.

More specifically, the invention relates to brake shoes for use in brake assemblies in which the shoes are fluid actuated, and the ends thereof are arranged to directly engage the pistons of the actuating cylinders. Such shoes are ordinarily fabricated of two parts, one consisting of a sheet metal strip curved to the form of a drum which forms the flange of the shoe adapted to receive for direct securement thereto thel usual brake l lining. The other comprises an edge-wise bent strip forming the web of the shoe and secured as vby welding to the` central portion of the flange so as to exlend inwardly thereof. They may also be fabricated of a rolled-section of T-form bent to the-desired curvature. Ordinarily the web portion of the shoe is extended beyond the flange at the ends of the shoe and is adapted to directly engage a piston of the fluid actuator.

It has been'found that shoes so constructed and actuated Idevelop squealing noises when the brakes are applied, and such noises are believed to be duetto vthe lateral instability of the end portion of the web where it projects beyond the ilnnge. Accordingly it is an object of the invention to'ove'rcome this difliculiy and to do this without materially adding to the weight or cost of the shoe. v

It is proposedo attain this object by laterally stiffening this'eex'tended portion of the web of the shoe and preferably by utilizing an extended end portion orportions of the flange of the shoe to accomplish this. There are shown in the accompanying drawing various ways of accomplishing the object of the invention, and it will be understood that the invention may be embodied in forms other than those shown and thatl other and further objects and advantages will become apparent from the following de tailed description of the forms of the invention as shown in the drawing forming a part of this specification.

In the drawing,

Fig. l shows an elevational view, parts being shown in section, of a brake assembly to which the invention is shown applied; Figs. 2 and 3 are enlarged fragmentary views of an end of a shoe according to the disclosure of Fig. 1, Fig. 2 being a perspective view and Fig. 3 a sectional view taken in a plane coinciding with the face of the web;

Figs. 4 and 5, and 6 and 7 are corresponding connected tothe end of the lever lavopposite views to Figs; 2 and 3 of modifications of the invention.

In thedrawing, the invention is shown applied to a brake assembly comprising the usual backing plate l0 bolted or otherwise secured vto the fixed axle housing, symmetrical brake shoes Il and l2 arranged on opposite sides of the vertical central plane of the backing plate, and brake cylinder actuators |3 and I4 arranged between the adjacent ends of the shoes. The shoes have their ends arranged to abut `the pistons at l5 operating in the cylinders I3 and I4. The engagement ofthe shoe ends with the pistons is one to permit floating movement of the shoes, and the shoes are held in their returned position by coil-springs i6 and Il. If desired, the shoes may be additionally ac uated by an emergency actuating mechanism comprising lever i8 hinged to one of the shoes'and acting through a link I9 upon the other shoe, a cable its hinged end forming. the actuating means for the lever.

Each of the shoes comprises an arcuate flanged portion 2l and a radially extending web portion 22 preferably bent to shape prior to assembly and then assembled together by welding the web to the flange. The flange carries the usual antifriction lining 23, shown in Fig. 1 but not shown in the detail views. Ordinarilythe flanged portion 2i would stop slightly beyond the arcuate portion carrying the lining, and the end ofthe shoe therebeyond being constituted solely by the web 22. In the preferred form, and according to the invention, the flange 2Ifis extended to the end of the shoe by lateral portions 24 and 25, which portions taper toward a narrow width at their extreme ends. In the assembly of the parts 2| and 22, thetapering end portion of the flange 2l is centrally slotted at 26, this being of a width corresponding to the thickness of the web 22. The lateral portions 24 and 25 of the end of the flange are bent to embrace the opposite sides of the end of the web, and form there'- with a substantially cross-shaped abutting end portion 2l. To stifi'en the entire end structure,

. it is understood that the lateral portions 24 and the direction of rotation of the drum. It ispreierred that this bearing area be very slightly rounded both vertically and transversely so that the shoe can tilt slightly with 'respect to the piston without placing undue forces upon thepiston tending` to tilt it on its axis and to prevent point contact between shoe and piston.

" According to the form of the invention shown in Figs. 4 and 5, the flange 2 I isextended as a -whole or at least for the' major portion of its width\to. overlap the top inclined end face 28,

and may be provided in this region with a hole 29 through which a portion 30 of the ange projects and i`s riveted over in nal assembly.. This draulic actuator which, in this embodiment, also yserves as anchor for the shoe ends depending on extended portion of the :flange 2| is here designated 32, and prior to assembly it is formed with lateral cut-out portions as 32. 'I'he portions 33 and 34 beyond the cut-outs 32 are then bent parallel to the end'portion of the web 32 and are secured thereto by welding, thus further reinforcing and 'stift'ening the extreme end of the web and providing an enlarged bearing area'for abutting relation with .the piston.` In this case alsothe abutting end may be vertically and transversely slightly curved for the same purpose as described in connection with the preferred form. l

In Figs. 6 and '7, a third modification is shown in which the tapered extended end 3'5 of the ange 2| is extended to overlap not only the inclined top portion 28 of the web 22 but also the horizontal top portion of the extreme end of the web and the vertical end of the web as Well 'as a short overlap with the off-set portion 36 of the bottom of the end of the web 22. This extended flange portion may be welded to all the faces of the web which it overlaps, and it mayl be additionally secured by a rigid connection smiilar to the connection 30 shown in Fig; 5. It willbe seen that in this form, the end of the web is again strongly stabilized laterally by the extended portion of the flange, and it is also widened laterally by the `width of the end of the extended flange portion to form a Wide seat for engagementof the piston.- In this case, the abutting end portion of the shoe may again be slightly curved in vertical and transverse directions for the purpose indicated in connection with Figs. 2 and 3 and 4 and 5.

It may be noted that in' each ofv the modifications described, the lateral stability of the extreme end of the shoe is assured by the integral extensions of the'ilange secured thereto so as toprovide not only llateral stability but an enlarged end bearing area throughwhich the shoe may engage the piston. v

It will be understood that the broad features of the invention could be obtained by a large number of variations of the above specifically ldescribed modications, and it is applicants purpose to cover all -such modications as readily fall within the spirit and scope of the terminology of the appended claims.

What is claimed is:

1a An arcuate brake shoe'fabricated of sheet -metal and having a transverse ange and a radial web secured thereto in its'medial plane, the ends of said web being of reduced radial dimension, said ends being laterally braced by extensions of said flange, the end faces formed by centrally to said transverse -ange portion, the

adjacent ends of both said radialweb and transverse-ange portions being of reduced dimension and secured together to form an end abutting portion having transverse andradial faces Aof substantially similar extent intersecting each other.

4. An arcuate brake shoe having a transverse ange portion and a radial web-portion secured centrally to said transverse ilange portion, both ends of `said radial web and transverse flange portions being o f reduced dimension and secured together to form end'abutting portions at each end of the shoev having transverse and radial facesv intersecting each other.

WARREN H. FARR. cARoLUs n EKSERGIAN; KARL o. HARLE.

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