US402503A - Automatic brake-adjuster - Google Patents

Description

I (NoMOdeL) J. B. BURNS.

AUTOMATIUBR'AKE ADJUSTER.

No. 402,503. Patented Apr; 30; 1889.

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, UNITED STATES PATENT, OFFICE.

JOHN B. BURNS, OF INDIANAPOLIS, INDIANA, ASSIGNOR OF ONE-HALF TO ELISHA D. EAMES, OF WATERTOWVN, NEIV YORK.

AUTOMATIC BRAKE-ADJUSTER.

SPEGIFIOATION forming part of Letters Patent No. 402,503, dated April 30, 1889.

- 7 Application filedSeptember 22,1888. Serial No. 286,091. (No model.)

To all whom, it mag} concern:

Be it known that I, JOHN B. BURNS, of Indi- The object of this invention-is to preserve,

automatically, the adjustment of the brakeshoes to the normal or prearranged distance from the Wheels intended to exist when brakes are oif, so that upon the wear of the shoes the increased amount of space between the shoes and the wheels will be at once taken up and the original distance between the shoes and wheels existing when the brakes are off reestablished. Various devices for effecting such a result have been projected, some of which have attained a greater or less degree of success. Of such may be mentioned Patent No. 352,444, granted November 9, 1886, to John B. Burns, and Patent No. 354,401, granted December 14, 1886, to Elisha D. Eames.

My present invention, which embodies the principle set forth in the said two patents, is designed to simplify, cheapen, and render more effective, safe, and reliable the mechanical appliances used.

In the accompanying drawings, Figure 1 is an elevation of a pair of car wheels with their brakes and appendages, showing the application thereto of my invention. Fig. 2 is a perspective view, upon an enlarged scale, of the parts entering chiefly into the invention detached. Fig. 3 is a sectional view of a detail on the line a b, Fig. 2. Fig. 4is a similar section upon the line 0 d of the same figure.

Similar letters of reference indicate similar parts of the invention in the respective figures.-

neled for the greater part of its length to a depth and width equal to the size in crosssection of the lower brakerod, E, which fits and is adapted to slide therein. It is not nec essary, however, that the bottom should be closed, as it may be entirely open, except for so much of the length at the inner end ofthe connection F as maybe required to hold it together and for strength. The inner end of the connection is shaped as seen in the cross-section, Fig. 4, and in Fig. 2that is to say, it forms a strap, shackle, or close bearing, f, entirely, but loosely, surrounding the rod E.

H is the link or rod pivoted at its outer end to the brake-lever D by the pin d. The said end of the link or rod H is forked, as at d,to straddle the lever D, and the fork is provided with a slot, (2 in which the pivotal pin d is adapted to havea movement equal to the pre determined distance between the brake-shoes and the wheels when brakes are 01f. The in- ,ner end of the link or rod His furnished with a strap or shackle, h,which fits loosely over the lower brake-rod, E, and is adapted to work thereon, as hereinafter described. It will be understood that the opposite end of the lower brake-rod, E, is pivoted to the brake-lever D.

The inner end of the short connection F is provided at its lower side with a hooked bracket or proj ection f with its cavity turned up, in which the lower end of a steel link, I,

- surrounding the brake-rod E rests, while the corresponding end'of the link or rod H carries a similar hooked projection, f but with its cavity turned down, in which the upper end of a second steel link, I, (also surrounding the brake-rod E,) rests. The steel links are preferably accurately fitted to the sides of the brake-rod E, so as to admit of no lateral play, but are permitted to have a slight swinging movement in the cavities of the hooked projections f f, as will be more particularly pointed out.

The operation is as follows: The distance which the brake-shoes are designed to move in setting the brakes is, as has been stated, the distance which the pin dis capable of moving in the slot (1 of the rod II. It is therefore seen that so long as the brake-shoes (they having been adjusted to have the required movement) are unworn the lever D will, in the act of setting the brakes, only move a distance sufficient to carry the pin d the length of the slot (1 and the link or rod II will therefore not be moved but wear of the shoes having occurred, in order to bring the shoes up to the wheels a greater movement of the lever D becomes necessary,when the link or rod H being drawn upon and the strap or shackle I'I moving upon the brake-rod E, the steel link I is diverted from its vertical position on the brake-rod to an inclined position, swinging, as it were, in the cavity of the hooked projection f and binding the top edge of the brake-rod E, shifting it toward the lever D, and consequently shortening the connections between the brakeshocs, taking up the slack, and restoring the distance which normally existed between the shoes,when off, and the wheels. The other steel link, I, acts exactly in the reverse manner, viz., to grip the brake-rod E and prevent its back movement upon the back motion of the lever D. It will be seen that the action is entirely automatic, and that the prescribed movement of the brake-shoes in the act of braking is always maintained.

The movement of the brake-rod E toward the lever D is checked by the end of the rod striking a pin, 1', standing across the forked end of the short connection F, while the movement of the brake-rod E in an opposite direction is limited by its pin i coming in contact with the shoulder k of the short connection F.

Having described my invention, I claim- In a brake mechanism, a brake lever, a short connection pivoted thereto, a brake-rod adapted to slide upon the short connectioma rod pivoted by means of a slot and pin to the brake-lever, and having at its inner end a strap or shackle, combined with a link surrounding the brake-rod and inloose engagement at its upper end with said shackle, and a second similar link also surrounding the brake-rod, but in loose engagement with the inner end of the short connection, substantially as set forth, the first link being adapted to grip the brake-rod as the brake-lever is moved to shorten said rod and the second link to detain the brake-rod and prevent its return movement upon the opposite motion of the brake-lever, as described.

In testimony whereof I have hereunto set my hand and seal.

, JOHN B. BURNS. [L. s.]

\Vitnesses:

W. M. COVAL, LEWIS A. STONEMAN.

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