US723334A - Brake-shoe. - Google Patents

Description

. PATENTED MAR. 24, 1903.

A. L. STREETER.

7 BRAKE SHOE. APB IIIIIIIIIIIIII AR. 111111 1.

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ALFRED L. STREETER, OF CHICAGO, ILLIN OIS, ASSIGNOR TO JOSEPI-ID.

- GALLAGHER, OF GLENRIDGE, NEW JERSEY.

BRAKE-SHOE.

SPECIFICATION forming part of Letters latent No. 723,334,-dated March 24, 1903. Application filed March 15.1901. Serial No. 51,393. (No model.)

To all whom it may concern:

Be it known that I, ALFRED L. STREETER,

a citizen of the United States, and a. resident of Chicago, in the county of Cook and State consists ofthe various features, combinations of Illinois, have invented an Improved Brake- Shoe, of which the following is a specification. I

This invention relates to brake-shoes, and relates particularly to brake-shoes the body portions of which are reinforced or strength ened by relatively strong tough metal.

The invention also has particular reference to brake-shoes of the general type having faces or friction -surfaces comprising relatively hard and soft portions.

The primary object of the invention is to provide a brake-shoe of this general type which shall be strong, durable, and efficient for braking purposes. I To this end a brakeshoe of my invention of features,and details of construction hereinafter described and claimed,

In the accompanying drawings a brakeshoe of my invention is fully illustrated.

Figure 1 is a side view of one form of brakeshoe embodying my invention. sectional view on the line 2 2 of Fig. 1. Fig. 3 is a sectional view thereof on the line 3 3 of Figs. 1 and 2, and Figs. 4 and 5 are longitu' dinal sectional views of modified forms of brake-shoes embodying my invention.

Referring now to the drawings, A designates the body ofa brake-shoe of my invention. l

Asshown in Figs. 1, 2, and 3,- my improved brake-shoe is provided with holes or openings a, which extend entirely through the same from the face or friction-surface to the back of the shoe, andthis I now consider the preferable form. of the shoe. My invention, however, contemplates. forming recesses or pockets a in the face or friction-surface of the shoe, which will be closed at the back and may be of any desired depth, as shown in Fig. 4 of the drawings. If desired, my invention also contemplates forming the brakeshoe solid, as shown in Fig. 5 of the drawings. My invention also contemplates forming recesses or pockets similar to the recesses or pockets at, in the back of the shoe. With Fig. 2 is a this construction it is obvious that as soon as the shoe wears sufliciently said recesses or pockets will form holes or openings in all respects similar to the holes or openings Ct. The number, size, shape, and disposition of the holes a and recesses a is a matter of judgment, and they may be varied as desired or to meetdilferent requirements. I

The entire outer portion of the shoe for a depth of, say, one-quarter (i) of an inch from all exposed surfaces consists of malleable iron. In the drawings this outer malleable portion of the shoe is indicated by relatively heavy shade or section lines and is designated by the reference-letter 0,

The inner portion of the shoe consists of cast-iron, which is relatively hard as compared with the outer malleable portions thereof. Said inner relatively hard cast-iron portion of the shoe is indicated in the drawings by the relatively light shade and section-lines and is designated by the reference-letter a The attaching-lug A is preferably madeintegral with the body portion A of the shoe and is proferably of malleable iron.

The face or friction-surface of the shoe, being soft, quickly wears, and thus adjusts itself to the contour of the car-wheel, thus rendering the shoe readily adaptable for use on wheels of different radii, it being well known that ordinary cast-iron brake-shoes are very liable to break and are, in fact, frequently broken when appliedin braking to wheels having larger radii than the initial faces or f fiction-surfaces of said shoes and before said shoes seat themselves thereon. Iconsider this an advantageous feature, but by no means essential.

The malleable layer at the back of the shoe operates to give necessary strength and toughness to the shoe to prevent its breaking under the strain of applying the brakes, said malleable back operating in the same. manner and performing substantially the same purposes as the steel backs or plates now commonly secured to the backs of cast-iron shoes. As compared with castiron shoes having separate strengthening-plates secured to the backs thereof, my present shoes possess material advantage in that the shoes may be worn much thinner, thus greatly reducing the amount of scrap and effecting a corresponding saving to the user. A further advantage of my present shoes as compared with shoes having separate strengthening-plates secured to the backs thereof is that the malleable back, being formed integral with the body portion of the shoe, effectually prevents pieces of the shoe from breaking off from the strengthening-plate and falling, which is a very objectionable feature of steel-back shoes, particularly when they are worn thin.

As soon as the malleable layer a on the initial face or friction-surface of the shoe is worn away the face or friction-surface of the shoe will consist at all stages of its wear of malleable-iron portions at the sides and ends of the shoe and around the holes or openings (1, Figs. 1, 2, and 3, and the recesses a, Fig. 4, and relatively hard cast-iron portions at points remote from the exposed surfaces of the shoe.

The malleable portions a at the sides and ends of the shoe and around the openings at, Figs. 1, 2, and 3, and-the recesses a, Fig. 4, being soft, operate to give the desired frictional engagement of the shoe with the carwheel to render the shoe eflicient for braking purposes, while the relatively hard castiron portions (1 being hard, render the shoe durable and increase the life thereof. Incidentally, also, the malleable portions or of the shoe, disposed so as to extend from front to back of the shoe, being continuous with the malleable layer 0. at the back of the shoe, operate, in connection with said malleable back, to render the shoe very strong, particularly in handling, before the shoe is put to its designed use. As preferably constructed, also, a brake-shoe of my invention is provided with raised beads or flanges a, which extend along the lateral edges of the back of the shoe, as clearly shown in Fig. 3 of the drawings. The advantage of this construction is that when the shoe is worn said beads or flanges a give the desired factor of safety and enable the shoe to be worn very thin, thus further reducing the amount of scrap formed when the shoe is worn out. In the preferable construction shown, also, the malleable portions a and the relatively hard cast-iron portions a of the shoe are not separated from each other by a clear and welldefined line; but they merge into each other,

as indicated by the section -liues. In this manner the formation or development of sharp cutting edges in the face or friction surface of the shoe is prevented as the shoe Wears, such sharp cutting edges operating to cut and gouge the treads of the wheels, es pecially steel-tired wheels, and being very objectionable.

Shoes embodying my invention may be conveniently constructed in the following manner: A shoe consisting entirely of White castiron is first formed, an ordinary sand-mold being preferably used for this purpose. After it is removed from the mold this White cast-iron shoe is placed in a furnace, such as is ordinarily used for converting White cast-iron into malleable iron, and is left there until such time as the outer portions thereof to a desired depth are converted into malleable iron. It is obvious that the thickness of the malleable shell will depend upon the length of time the shoe is allowed to remain in the furnace. It is also obvious that the attaching-lug A, being relatively small and being exposed on several sides to the action of the furnace, will be converted into malleable iron throughout in a desirable manner.

I claim 1. A brake-shoe provided with an opening or openings in its face or friction-surface, a layer of malleable iron disposed at the back of the shoe, layers of malleable iron on all exposed surfaces of the shoe extending from the face or friction-surface toward the back thereof and relatively hard cast-iron portions, substantially as described.

2. A brake-shoe provided with an opening or openings in its face or friction-surface which extend entirely through the shoe, a layer of malleable iron at the back of the shoe, layers of malleable iron on all exposed surfaces of the shoe extending from the face or friction-surface toward the back thereof and relatively hard cast-iron portions, substantially as described.

In testimony that I claim the foregoing as my invention I have hereunto set my hand this 6th day of March, 1901.

ALFRED L. STREETER.

Witnesses:

BYRON B. CARTER, ARTHUR F. EVANS.

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