US555975A

US555975A - Brake-shoe

Info

Publication number: US555975A
Authority: US
Publication date: 1896-03-10
Anticipated expiration: 1913-03-10

Description

(No Model.)

W. D. S ARGENT. BRAKE SHOE.

No. 555,975. Patented Mar. 10, 1 896.

s MW dag ANDREW B GRANAMFPMOTQ-LIMQWASNINGTON. 0.0

NlTED STATES Fries.

ATENT BRAKE-SHOE.

SPECIFICATION forming part of Letters Patent No. 555,975, dated March 10, 1896.

Application filed December 13, 1895. Serial No. 572,05 '7. (No model.)

To all whom it may concern.-

Be it known that I, TILLIAM I). SARGENT, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Brake-Shoes, of which the following is a full, clear, and exact description, reference beinghad to the accompanying drawings, forming a part of this specification.

This invention relates to the class of brakeshoes known in the art as dressing brakeshoes, because, in addition to their function of brakes, they serve the purpose of dressing the entire tread and flange of car-wheels in proportion to the wear on said wheels resulting from contact with the rails. This class of brake-shoes is exemplified in Letters Patent of the United States No. 523,084, granted to me July 17, 1894, upon which my present invention is more especially designed as an improvement.

The primary object of this invention is a brake -shoe which will not only dress carwheels proportionately to the wear thereof, due to contact with the rails, so as to 1nai11- tain the tread and flange of the wheels in uniform and proper condition at all times during their lives, but will also possess the maximum degree of longevity in service without detriment to the strength or braking quality of the shoe.

A further object is to provide a brake-shoe with a wearing-surface that shall be practically continuous over the tread and flange of a car-wheel, which will dress with maximum effect those portions of the wheel which do not contact with the rail, and which will dress those portions of the wheel that are worn by contact with the rail with proportionate effect and which will yet have a composite metallic wearing-surface, a portion of which is directed to afford a braking effect, while the other portion serves to retard the wear of the shoe.

Another object of the invention is a brakeshoe having integral hard and soft or composite metallic wearingsurfaces, which shall possess in the maximum an exceptional degree of strength, durability, and effectiveness.

These and such other objects as may hereinafter appear are attained by the device illustrated in the accompanying drawings, in which- Figure 1 is a perspective view of a brake shoe provided with alternate chilled parts and in Fig. 0. ordinary flat brake-shoe. Fig. 0 is .a crosssectional view of a flat brakeshoe, showing a flange on the back thereof; and Fig. '7 is a diagrammatic view illustrating the wear upon a wheel and the position of the chilled parts in the brake-shoe with relation to the wear on the wheel.

In all of the figures, A designates the body portion of the brake-shoe, and B the chilled parts thereof. These chilled parts may be variously disposed, and in Fig. 1 I have shown them arranged alternately with openings 0, one or more of which may be provided as desired. In this case the chilled parts extend through all that portion of the shoe between the openings, as clearly shown in Fig. 1.

In Fig. 3 I have shown anumber of chilled parts with narrow webs I) separating said parts, and in Fig. 5 the webs separating the chilled parts are wider than those shown in Fig. 3. These chilled parts may be made in many ways, but a common way is to subject parts of the shoe to the action of a cold piece of metal in the process of casting. The chilled parts may be of any desired configuration and size, audit will be understood by those skilled in the art, as well as by others, that the number and size, as well as the location and arrangement of the chilled parts with relation to the other parts of the brake-shoe, will vary under different conditions, but the chilled parts are arranged in such a position with relation to the other parts of the brake-shoe that they will be located opposite to that portion of the wheel which is Worn by contact with the rail, and those portions of the wheel which do not contact with the rail, and therefore are not worn, will be dressed by the soft parts of the brake-shoe around the chilled parts thereof with maximum effect.

In Fig. 7 I have shown the preferred location of the chilled parts with relation to the wear on the wheel. In actual use it will be found that the chilled parts of the brakeshoe wear more or less, but they do not have the dressing effect upon the wheel that is afforded by the other parts of the brake-shoe. While the soft parts of the brake-shoe wear the wheel by reason of the grinding action afforded by the particles rubbed off of the shoe the chilled parts form polished surfaces and do not, to any material extent, dress the por tion of the wheel with which they come in contact. The chilled parts merge into the soft parts of the shoegradually, and the corners thereof are rounded, as at F, whereby the dressing-face of the shoe is gradually enlarged on either side of the line where the wheel is worn the most by the rail.

The foregoing will be clearly understood by referring to the diagrammatic view, Fig. 7, in which G represents the car-wheel; H, the rail; I, a portion of the brake-shoe; J the original outline of the car-wheel, and K the outline showing the ordinary wear upon a carwheel by the rail to which a dressing brakeshoe has not been applied in service.

That portion of the wheel-tread between the lines a a represents the area of maximum and practically uniform wear of the rail upon the wheel-tread.

That portion of the wheel-tread between the lines a and b and a and 1) represents the area of proportional wear of the rail upon the tread, the minimum wear being at about the lines I) b. That portion of the tread and flange between the lines Z) c and b a represents the area of no wear upon the wheel by the rail, because these portions of the wheel never come in contact with the rail. It is therefore desirable to dress with maximum wearing effect substantially that portion of the wheel tread and flange included between the lines I) c and b c, to dress with minimum wearing effect that portion of the wheel-tread between the lines a and a, and to dress with a proportionate effect from the maximum to the minimum that portion of the wheel tread and flange between the lines a Z) and a b. That portion of the shoe indicated by the letter d is intended to illustrate the merging of the chilled portion of the brake-shoe into the soft or unchilled portion thereof, and while I have shown in this view and in the other views a comparatively sharp line of demarcation between the chilled and unchilled or soft portions of the shoe, in practice no such line does or can exist, as the eifect of the chill will extend, in a rapidly-lessening degree, from the desired outlines of the chilled portion into the soft portion, so that the wearing-surface of my brake-shoe, in point of fact, is of composite metal of three degrees of hardness, the hardest being over the area of maximum wear, the softest being over the area of minimum wear and the intermediate being over the area of proportionate wear of the rail upon the wheel.

I am aware that there are many different constructions in the art which propose or attempt to provide for the uniform dressing of wheels aside from my patented invention hereinbefore referred to, but so far as I am aware it is broadly new to provide chilled parts in a brake-shoe which are disposed so that they will contact with or be located opposite to that portion of the wheel which received the greatest wear by contact with the rail.

The use of chilled parts in the manner I have described will provide a brake-shoe of great strength and durability.

In Figs. 4: and 6 of the drawings I have shown the rib E, which is provided on the back of the brake-shoe for attachment to the brakehead. I have also shown two different forms of brake-shoes in these drawings which appear to be sufficient for the purpose of fully disclosing the invention, but it will be understood, of course, that the improvements may be embodied in brake-shoes of any kind not inconsistent with the purposes of the invention.

It will be noted in Figs. 2 and 6 more especially that the contour of the wearing-surface of my shoe does not coincide exactly with that of the wheel tread and flange, or, in other words, that the chilled portion practically spans between the tread and flange of the brake-shoe over the areas of maximum and proportionate wear and does not make contact therewith. This condition, however, to the fullest extent exists only when the shoe is first applied to the wheel, the length of span gradually lessening as the shoe wears, until finally the contour of the shoe and wheel will actually correspond. This feature is important in order to avoid detriment to the full effectiveness of the brake-shoes when first applied, which might result from carelessness or the exigencies of chilling, when the chilled portion might otherwise serve for some time to prevent the application of the full wearing-surface of the shoes to the wheels when first applied, and consequently prevent the maximum braking effect of the shoe being brought into play.

I am aware that changes and variations in the form and proportion of the different parts of my improved brake-shoe may be made without departing from the spirit or sacrificing the advantages of the invention, and I would therefore have it distinctly understood that I reserve to myself the right to make all such changes as fall within the spirit and scope of the invention.

Having thus fully described my invention, what I claim, and desire to secure by Letters Patent, is

1. A brake-shoe composed of cast metal having chilled parts in its wearing-surface so disposed as to contact only with that portion of the wheel which contacts with the rail, substantially as described.

2. A cast-metal brake-shoe having a composite integral wearing-face composed of unchilled cast metal, chilled cast metal and parwith the rail, that portion of the shoe between such continuous wearing surfaces being chilled so as to leave a substantially uniform wearing-surface of chilled metal over the area of maximum wear of the rail upon the Wheel,

approximately from a to a, and gradually decreasing wearing-surfaces of chilled metal between said uniform chilled portion and the said continuous wearing-surfaces, approximately from a to b and a to b, substantially as described.

4. A brake-sh0e composed of soft metal having chilled parts located in the wearingsurface of said shoe opposite that portion of the wheel which contacts with the rail, said chilled parts being substantially uniform opposite the area of maximum wear of the wheel and gradually reduced from said uniform portion at each side to approximately a point Where the wear of the rail upon the wheel ceases, substantially as described.

5. As a new article of manufacture, abrakeshoe having parts of its wearing -surface chilled opposite that portion of the wheel which contacts with the rail, said chilled portion being adapted and arranged to span the area of the wheel worn by contact with the rail when first applied to the wheel, substantially as described.

WILLIAM D. SARGENT.

WVitnesses:

M. E. SHIELDS, F. H. DRURY.