US651032A - Brake-shoe. - Google Patents

Description

No, 65|,u32, Patented June 5, |900. J. D. GALLAGHER.

BRAKE SHOE.

(Application filed Dec. 13, 1899.)

(No Model.)

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"NiTnD STATES PATENT OFFICE.

JOSEPH D. GALLAGl-IER, OF GLEN RIDGE, NEIV JERSEY.

BRAKE-SHOE.

SPECIFICATION forming part of Letters :Patent No. 651,032, vdated. J une 5, 1900. Application filed December 13, 1899. Serial No. 740,177. (No model.)

and particularly to that class yof brake-shoes composed partly of soft iron and partly of chilled iron. In shoes of this class the soft iron, forming by far the larger portion of the shoe, gives the principal frictional resistance or retarding power, while the smaller portion of chilled iron, while affording some frictional resistance, is particularly useful in giving life to the shoe-that is, in increasing the length of time it will wear. Heretofore shoes of this class have generally been chilled on the face of the shoe, usually in sections, as.

shown in the patents to Lappin. Shoes thus made have been largely used and have givenl excellent results. Two defects have, however,

long been recognized in all shoes of this classV first, the liability of these shoes chilled on the face to develop aweakness at the lines of union between the chilled and soft sections, which is commonly in its more lpronounced form called a chill-crack, and to break in service or handling along these lines; second, when the chill Was made light-that is, of no great depth-in order to overcome the first difficulty the shoe during the rst portion of its life until the chilled sections were worn through would wear slowly; but as soon as the chilled sections were Worn off it became a soft -shoe and wore out quickly. Thus the same shoe would at differentl periods of its life require different brakeleverages to properly operate it, so as to get the maximum braking eect and, in addition, to get much increase of life over the life of a soft-iron shoe. The proportion ofchilled area at first had to be much larger than would have been required had the chills penetrated the whole depth of the slice, as the whole additional wearing quality of the shoe was confined to about the rst one-third of its thickness. In his patent of October I, 1889, Samuel Hatt made the first effort to improve on the shoe chilled on its face and devised a shoe chilled on its sides and ends only and having a uniform margin of chilled metal all around it and extending substantially from its face to its back, so that there would be, in his words, a uniform relative proportion of chilled and soft metal throughout the planes of its wear from front to back. This shoe was an improvement over the shoe chilled on its face in that'it had not its tendency to break, maintained a uniform proportion of chilled and soft metal throughout its life, and enabled the use of a much larger area of soft iron for frictional purposes without in any way lessening the life of the shoe. This Hatt shoe had, however, two defects which interfered with its usefulness. The most important of these was that the chilled side margins being of the same width from end to end of the shoe and when the shoe was in use always contacting with the tread of the wheel at substantially the same place tended to make certain classes of wheels wear unevenly-that is, the chilled and soft longitudinal sections of the'shoe exerted different degrees of wear on the wheel. The second defect was that the side'chills ran of substantially-equal width along that portion of the shoe adjacent to the center lug, which, especially in the Master Oar-Builders standard shoe, is the weak point of the shoe, andv in some degree weakened the shoe at the lug. I have endeavored to cure both of the defects in the Hatt shoe, while retaining its meritorious features. To do this, I have devised a shoe chilled on its sides and ends only, as is the Hatt shoe, but having the chills either exceedingly light at the center of the shoe,A or begin a little on each side of the central lug of the Master Car-Builders standard shoe and gradually increase in depth as they approach the ends, so that the side chills will substantially meet at a point on the extreme ends of the shoe, or, if end chills be also used, Will form a curved chill around the extreme ends of the shoe.

I will now describe the figures.

IOO

Figure lis the face of the shoe of this invention after the soft-iron face C has been worn away and shows the relative shapes and proportions of the chilled and soft metal both when side chills are used alone, as at B', and when end chills are also used, as at B. Fig. 2 is also the face of the shoe, showing the shapes of the chilling-blocks used to produce the graduated chills, D' being the shape when side chills alone are used, and D the shape when side and end chills are both used. Fig. 3 is a side elevation of the shoe, showing the soft face C and also showing the soft iron adjacent to the central lug.

In the drawings like letters of reference indicate like parts, and for convenience of illustration the Master Car- Builders standard shoe is used.

In the drawings, A represents the soft-iron section of the shoe.

B and B represent the chilled sections, B when end as well as side chills are used, and B when only side chills are used.

C represents the soft-iron face left on the shoe to enable it to quickly weardown into true conformity with the wheel.

D and D' in Fig. 2 represent the preferred form of chilling-block used to form the chilled sections, D when end and side chills are used, and D when only side chills are used to produce the graduated chill, and in Figs. l and 2 the dotted lines w represent the place where the lug is located on the back of the shoe, and in Fig. 3, @c represents the lug. Of course it is manifest that these chilling-blocks made very thin may, for convenience, extend along the whole side of the shoe, the very light resulting chill in no way affecting the utility of the shoe.

The principal feature of my invention is the graduated chill--that is, a chill gradually increasing in Width from a point at or near the center of the shoe until the two side chills practically meet at the extreme ends. A preferred form of this invention is to have the chills actually begin a full inch on each side of the central lug when a Master Car-Builders shoe is used, so that there will be no chilled metal at or closely adjacent to the lug, and I prefer to chill from the ends as well as the sides.

I will now describe the method of making the preferred form of my shoe.

I make the shoe by embedding in the mold prior to casting in the usual way chillingblocks D, which extend from a point on the pattern about one inch on each side of the central lug to and around the ends of the shoe. These chilling-blocks are preferably very thin at the center of the shoe, though if the chill is to begin at a distance from the central lug they may be made heavier'and gradually increase in thickness as they approach the end of the shoe and extend around the end of the shoe of substantially the same thickness as at the thickest part of the sides.

It is Well known that the depth of the chill will approximately be proportionate to the thickness of the chilling-block, and by thus gradually increasing the thickness of my chilling-blocks I gradually increase the depth of the corresponding chill. In the mixture of iron I use to make my shoes, which is substantially a car-wheel iron, I find a chillingblock of a maximum thickness of one inch sufiicient; but it is not possible to give any exact rule, as the depth of the chill from the same block will vary with the iron used. I prefer to slightly round the corners of the shoe at the ends, ,as shown in Figs. l and 2, as it tends to curve the chilled section and also enables the more easy removal of the shoe from the chilling-block. I make these chilling-blocks from one-quarter to one-half an inch less in depth than the shoe, so that the face of the shoe will for a slight depth be entirely of soft iron. When these chillingblocks are in position in the mold, the pattern is placed in them or the pattern and chilling-blocks may be introduced at the same time, the pattern being preferably so placed that the shoe will be cast face up. The mold is then formed in the usual manner, the pattern removed, and the shoe is then ready for casting. W'hen cast, it will be found on examination to have a chill on the sides gradu` ally increasing in depth from the beginning of the chill until the side chills substantially meet at the ends, and if an end chill has been used the chilled section will be curved at the ends, as shown at B in Fig. 1.

When this shoe is used against the tread of the Wheel, it will be found that the wheel is evenly worn, and when this shoe is tested under the drop it will be found that it has all the strength of a soft-iron shoe. It will also be found that this form of chill permits the use of the smallest area of chilled metal in proportionto the soft metal ,While not decreasing the life of the shoe.

I claim- 1. A brake-shoe having a marginal portion of chilled metal formed on its sides, such marginal portion being of the least thickness at the center of the shoe and gradually increasing in thickness as it approaches the ends, substantially as described.

2. A brake-shoe having a maginal portion of chilled metal formed on its sides, such marginal portion being of the least possible thickness at the center of the shoe and gradually increasing in thickness as it approaches the ends and extending substantially across the ends,` substantially as described.

3. A brake-shoe having a marginal portion of chilled metal formed on its sides and ends, such marginal portion being of the least thickness at the center of thc shoe and gradually increasing in thickness as it approaches thc ends and extending around the ends of the shoe, substantially as described.

4. A brake-shoe having a marginal portion IDO IIO

of chilled metal formed on those portions of In testimony whereof I affix my signature its sides not adjacent to the center lug, saidY in presence of two Witnesses.

marginal chills being thinnest at the points Y nearest the center of the shoe and gradually JOSEPH D' GALLAGHER increasing in width as they approach the ends Witnesses:

of theshoe and extending-'substantiallyacross CHARLES W.- BROWER,

the ends, substantially as described. FRANK B. SMITH.

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