US247830A - Car-brake - Google Patents

Description

(No Model.)

A.JOHNSON.

GAR BRAKE.

Patented Oct. 4,1881

UNITED STATES PATENT OFFICE,

ALONZO JOHNSON, OF SPRINGFIELD, MASSACHUSETTS.

CAR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 247,830, dated October 4, 1881,

Application filed April 6, 188i.

To all whom it may concern Be it known that I, ALONZO JoHNsoN, a citizen of theUnited States, residingat Springfield, in the county ot'Hampden, State of Massachusetts, have invented new and useful 1mprovenients in Gar-Brakes, of which the following is a specification.

This invention is in the nature of an improvement upon my patent of December 7,1880,No. 235,152, and relates to the details of construction of an improved chain-drum and operatinglever for ear-brakes, and to improvements in stop devices for said chain-drum, the object being to prevent said chain-drum from revolving too far when the brakes are let off, and to provide such a construction of pawl-lever as willprotect the teeth ofthe ratchet on the chaindrum from snow and ice.

In the drawings, forming part of this specification, Figure 1 is an isometric view of a carbrakc embodying my improved chain-drum stop devices, and showing a modified construction of pawl-lever. Fig. 2 is a side elevation, partly in section, of a oar-brake embodying my improvements in said chain-drum stop devices and in said operating or pawl lever. Fig. 3is a view of the pivot end of said operating-lever.

In the drawings, A is the frame of the brake. c is the chain-drum, provided with a ratchet around it, as shown. d is the pawl-lever. e is the pawl. i is the brake-chain. 0 is a chainbolt in the drum 0. w is astop-cl1ain attached to drum 0 and to the frame of the brake. s is a stop-lever. t is the weighted end of the stoplever s. d is a guard-plate on the pawl-lever d, and d is a ratchet-guard on plate d (1 is a modified construction of pawl-lever.

The improved chain-drum herein shown is constructed with an opening therein, a, so that one side of the drum opposite to said opening will be heavier than the other, or the same end would be attained by otherwise constructing the drum so that its side opposite to that to which the brake-chain i is attached would be the heaviest, the object of so constructing said drum being to cause -said drum to turn to such a position after the brakes are released as will cause the bolt 0. to stand at or near the top of the drum, so that when the pawl-lever d is operated to turn drum 0 one or two motions of (No model.)

said lever carrying the pawl 0 against the teeth on said drum will be sufficient to cause the requisite strain to be put upon the brakes, for 'the reason that no motions of the lever (1 will then be required to take up the slack in the brake-chain before said chain will begin to draw upon the brakes; for it will be easily understood that if the bolt 0 stands over toward the under side of the drum when the pawl-lever d is operated to wind up chain t, it Will require several more motions of said lever to cause the chain to draw upon the brakes than it will if the bolt 0 stands in the position shown in Fig. 2 when the lever 61 is first operated. Another means for preventing the chain-drum c from turning too far around in a direction toward the pawl when the brakes are let off, is provided for in the stop'chain m, which is secured to said chain-drum by the bolt 0 or other convenient means, and to the frame A, as shown, or to the roof of the car or other suitable fixed point. Thus when said chain-drum is rapidly thrown around by the recoil caused by its sudden disengagement from the stop-lever s, the said drum will revolve only so far as it is permitted to by the length of said chain 00. Thus sufficient slack can be given to the brakechain 2' to release the brakes, and still hold the drum 0 in such position that one or two open ations of the lever d and the pawl 0 upon said drum will suffice to take up sufficient of the slack ofchain to cause the brakes to be brought firmly against the wheels of the car.

By the employment of the above-described improvements for controlling the backward revolutions of the chain-drum when the brakes are let off, the brakeman is enabled to quickly and surely apply the brakes to a car, generally with one motion of the brakelever d.

The improvement in the pawl-leverd, whereby the ratchet-teeth on drum 0 are protected from snow and ice, consists in securing to the part of said lever which lies by the side of drum 0 a vertical guard-plate, (2 which reaches up above said ratchet-teeth, and has upon its top edge a ratchet-guard, d standing at right angles to said plate 61 and extendingoutover said ratchet-teeth far enough to so cover them that snow and ice cannot fall thereupon and prevent the proper action of the pawl e therein.

ICG

The pawl-lever (1 (shown in Fig. 2) illustrates still another improvement over the construction shown in my said patent, and one which permits of keeping thelower end thereof within the limits of frame A, and thus admits of being covered over, if desired. Said improvement consists in extending its lower end in a straight line beyond its pivot-point, as shown, and in setting a stop-bolt, r, into the frame A, against which said lever may strike when its upper end has been swung as far as it should be to rotate said chain-drum, the object being to stop said lever (1 when it swings against the stop-bolt r, as and for the purpose stated in my said patent.

The stop-lever s,pivoted in the frame A, and adapted to engage in the teeth of the ratchet upon chain-drum 0, illustrates an improved construction and location thereof, inasmuch as said stop-lever is located almost entirely within frame A, and having itstreadle end extending toward the center thereof. Thusit can be protected from snow, &e., by covering frame A, and is disengaged from .the ratchetteeth by hearing down upon the treadle end of the lever under the frame, and when said lever is free to operate, its weighted end t causes it to engage with the ratchet-teeth on drum 0, and hold said drum wherever it may be left after applying the brakes. A pin, I), is fixed in the frame A in such position that when lever d is brought down horizontally, as in Fig. 2, the under side of pawl 42 will strike said pin, and the pawl will be lifted out from the teeth of the ratchet,as there shown, leaving the stop-lever t as the soleimpediment to the turning of the chain-drum by the strain of the brake-chain upon it.

The modified construction of the pawl-lever (1 (shown in Fig. 1,) whereby the lever is carried down from its pivot-pointin frame A, under the edge thereof, and its end is brought up inside and has the pawl hung to it, as shown, permits of covering over the top of frame A, and so protecting the operative parts of the brake within it from snow and ice. When said pawl-lever (1* is made as shown in Fig. 1 it is not essential that there be arranged upon the frame A any projecting point against which the lever may fall when in a horizontal position, as in Fig. 2, for that portion of said lever which passes down under the lower edge of said frame acts as a support to said lever when it is thrown down, although anysuitable device may, if desired, be attached to the side of frame A, to support the end of the lever d, instead of leaving it to be supported solely by that portion which passes under frame A, as just described.

The pawl-lever (1 may have a stud secured in it opposite the pivot-point of the pawl e, to which said pawl maybe hung, instead of supporting it as herein shown; but such construction would not afford so good facilities for covering the frame as that shown herein, and the lever or frame may be adapted to let the lever fall to a horizontal position.

The operation of my car-brake embodying the improvements herein shown and described is as follows: When the pawl-lever d lies in the position shown in Figs. 1 and 2 the pawl 0 lies upon pin a, which projects beyond the inner face of frame A, and is raised up away from the ratchet-teeth around the chain-drum c. The brake chain 1', secured to said chaindrum and extending thence to the brake-levers under the car, hangs in the position shown in Fig. 2, the stop-chain m preventing said drum from being further revolved by the weight of chain tor other cause, and the stop-levers, when not interfered with, is held so that its tooth z is in constant contact with the ratchetteeth around drum 0 by the action of its weighted end 1;. To apply the brakes to the car-wheels lever cl is lifted from a horizontal position and swung over to a vertical one, causing pawl e to be lifted away from pin a and letting its point drop and engage in said ratchet-teeth and to turn the drum 0, winding chain t thereon and causing the brakes to be drawn against the car-wheels. Lever (I may be so operated successively until chain t'draws sufficiently for the above purpose, when stoplever s will hold the drum where lever d may leave it, and the stop-chain or will be slack, as seen in Fig. 1. Lever (I will, when released, drop down to a horizontal position again, so as not to be in the way of the brakeman when passing over the car, and to be out of the way of low bridges. To let off the brakes, as it is termed, the brakeman presses his foot on the treadle end of the stop-lever s, under frame A, disengaging tooth z from the ratchet-teeth and letting drum 0 be turned back by the strain of chain t upon it. Said drum 0 is free to turn back just far enough to give chain 1 the requisite slack to free the brakes from the wheels, but is prevented from turning further by chain 00, or by making drum 0 heaviest On its side opposite to bolto. Thus said drum is leftin the most advantageous position, as heretofore described, to permit the brakes to be reapplied by a simple single motion of lever d.

\Vhat I claim as my invention is- In combination, frame A, the pawl-lever d, pawl c, chaindrum c, stop-lever s, the brakechain 1, and appliances, substantially as described, for stopping the revolution of said drum when the brakes are let off, substantially as set forth.

ALONZO JOHNSON.

Vitnesses:

H. A. GHAPIN, J. D. GARFIELD.

Images