US129868A - Improvement in steam and air car-brakes - Google Patents

Description

Patented my 23,1872.'

IEESII 1.-Y. SNHTH. y y nSteam and Air CarfB-rakes.

lmprovementi PATENT- ,.IorINr.` SMITH, or rrrrsnnne, PENNSYLVANIA.

"f IMPRovEMi-:NT IN ,STEAM AND AIR'CAR-BRAKES.

- specificati@ forming part of Letters Patent No. 129,868, dated July 23, 1872.Y

. `series of diaphragms, which, collapsing when the vacuum or partial vacuum is created, draw uponthe brake-rods or connected mechanism for operating such brake-rods with a pressure due to the diierence of atmospheric pressure on the outsideahfd inside of such diaphragm.

In the annexed drawing, Figure 1 is an elevationof an engine and tender with my im- `proved brake applied, showing, also, two

"modes of creating avacuum; or partial vacuumw .in the pipe.. Figs 2,;is aplan, showing the bot- `tom of a car as seen looking upward from below. Fig. "3is a longitudinal section of an inc jector proposed tolbe usedin exhausting the air from the pipes and diaphragms. Fig. 4. is

a vertical section of avalve proposedA to be used in connection with the exhaust-pipe when the exhaustion is produced by a pump or by the cylinder; and piston of the locomotive used as air-pump. Fig. 5 is an enlarged view of the diaphragm. y i

In all the iigures `the same letters are employed in the designation of identical parts.

In the annexedfdrawing, A indicatesa `mc- `tallicpipe extending from the locomotive under the tender and all the cars of the train. ThisA pipe willbe made in sections. Those `fastened to each car may be rigid, and these sections should be connected by other sections which are iiexible, so as to permit the free motion of the cars without breaking the continuity of the pipe. The ilexible and rigid sections should be so attached by coupling that they may be conveniently disconnected or connected as cars are taken from or added to the train, As such couplings are in common use it is unnecessary here to describe them. B in Fig. 1 indicates the cylinder of a locomotive. The pipe A opens through the top of the steamchest. When the steam is shut off by means of the throttle-valvethc piston will act as an air-pump to draw air out of the pipe and dis- Vexcept under the valve a?.

tle-valve is open, a check-valve, shown in l Fig. 4 and Vattached to the pipe A, is closed.

by the pressure of the steam on topof the valve al. When the piston is acting as an airpump, after the steam is shut off and a cock at A3 is opened by the engineer, the pressure of air on the under side of the valve,V al will raise the valve and allow the air to low out of the pipe A into the cylinder. A diaphragm, a2, placed in the, pipe A, prevents the air passing Attached to the pipe A is also placed an injector, C, shown in sectionin Fig. 3. The steam entering through the upper pipe into the chamber Cl passes back through the nozzle, into which is fitted a plug, G3, of conical form, which may be regulated by a hand-wheel, C, so as to control the force of the steam-jet. A dial-plate (not `shown in the drawing) may be connected with the hand-wheel to indicate the position of the regulating-plug. The air in the pipe A will be drawn through the lower opening, shown in Fig. 3, and driven out with the steam into vthe open air, thereby causing a partial vacuum in the pipe A. This injector may be used alone or in connection with the cylinders used as an air-pump. In any case it will be important in maintaining the vaccum when the train has been stopped on an inclined portion of the track. The air may be let into'tlie pipe A to supply the vacuum and let off the brakes by means of a -valve within convenient reach of the engineer at any point behind the injector. A check-valve should also be placed in the pipe connecting the injector with the pipe A. Under each car the pipe A is connected by a branch pipe with a diaphragm or series of diaphragms, D. These diaphragms may be constructed of India rubber, India-rubber cloth,

or thin plates of elastic metal, corrugated so FFIGE.

fastened, and the opposite side, or sideof the one at the opposite end of the series, is to be in like manner connected with a reciprocating rack-bar, E, working in suitable guides. The branch pipe must be suitably braced, so as to sustain the strain upon it. The rack on the bar E engages the teeth of the spur-pinion F, on which studs F are placed, secured in radial slots so as to permit their adjustment nearer to or further from the center of the wheel F, to increase or diminish the leverage. Instead of fastening the studs to a wheel they may be attached to a bar bolted thereto, and instead of the rack and pinion a system of levers such as are in common use in operating car-brakes may be connected with the bar E. A chain, G, is wound around the studs F', as shownin Fig. 2; and this chain, or rods attached thereto, may be connected directly with the ordinary cross-bar of the brakes H, or to levers `such as are in common use for operating brakes applied to the opposite sides of the wheel. When the air is exhausted from the pipe A it will at the same time be drawn from the interior space between the diaphragms, and they will be collapsed by the pressure of the external atmosphere applied to their entire outer surface by a force proportionate to the degree to which the vacuum is produced. This pressure in forcing the diaphragms together will draw the rod E toward the diaphragms, and by means ofthe mechanism shown, or the system of levers used instead thereof, will draw thebrakes against the wheels with a force depending upon the amount of the atmospheric' pressure and the multiplication of power caused by the intermediate mechanism employed. The brakes should be provided with the usual springs for drawing them back when released, and the tension of these springs must also be sufcient to move the intermediate mechanism and distend the diaphragms when the air is let into the pipe A by the engineer by means of the valve mentioned as used for that purpose; or this distension may be produced by forcing air into the pipe by means of a pump or injector.

I am aware that vacuum-brakes are not new, both ilexible diaphragms and cylinders and pistons having been proposed to be used. I am also aware that it is not new to use the cylinders of the locomotive as an air-pump for exhausting the air to operate the brakes. I am also aware that divers forms of air-pumps have been proposed, both those operated by the driving mechanism of the locomotive and steam-jets or injectors. I do not, therefore, claim these or any of them independently. In Nehemiah Hodges patent of 1860 he covers by his claims the use of an elastic diaphragm for this purpose; but to exhaust the air from the diaphragms he proposed to use an air-pump operated by the moving parts of the locomotive, making use of a vacuum-chamber to maintain the pressure on the brakes when the train was stationary. I have no doubt of the great superiority of the flexible diaphragm, but the operative mechanism, I think, is objectionable; so Westinghouse has proposed to use a steam or air jet for drawing the air out of the cylinder to free the piston from back pressure, or to operate it by atmospheric pressure. But the cylinder and piston are in my opinion entirely unfit for this purpose, on account of the amount of friction'to be overcome, from which the flexible diaphragm is free. I believe myself to be the ,first to unite the advantages of the steam-jet as an exhaust and the flexible diaphragm, by which means the exhaust may be regulated and continued and friction avoided, and thereby the Hodge brake improved.

What I claim as my invention as an improvement on the vacuum-brake for railway cars patented by Nehemiah Hodge is 1. In combination with a ilexible diaphragm for operating the car-brakes, an exhaust-pipe containing a nozzle for injecting a current of steam to induce an outward flow of the air, substantially in the manner set forth.

2. In combination with the diaphragm, reciprocating-rod E, pinion F, and chain Gr, for

5to this specification in the presence of two subscribing witnesses.

JOHN Y. SMITH. Witnesses:

A. RUPPERT,

B. EDw. J. EILs.

applying pressure to the brake H, snbstan- Y

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