US199540A - Improvement in vacuum-brakes for railway-cars - Google Patents

Description

` J. s J. G. HARDY. Vacuum-Brakes for Railway-Gars.

. Patented Jan. 22, 1878.

N. PETERS. PHOT0L|THOGRAPMER, WASHINGTON. DJI,

UNITED STATES PATENTOEEICE.

.IOHN HARDY AND JOHN GEORGE HARDY, OE VIENNA, AUSTRIA.

IMPROVEMENT `IN VvAouulvl-I aFaAKES FOR RAILWAY-CARS.

Specification formingpart of Letters Patent No. 199,540, dated January 22, 1878; application filed l May 31, 1877.

To all whom t may concern: l

Be it known thatwe, JOHN HARDY and JOHN GEORGE HARDY, both of Vienna, in the Empire of Austria, engineers, have invented Improvements in Railway-Brakes, of which the following is a specification:

and, secondly, to so arrange 'the brakes and air-exhausting pipes on a train of cars that.

the brakes on the engine and tender may be applied simultaneously with or before those on the cars.

These Obj ects we attain in the manner which we will now proceed to describe, reference being had to the accompanying drawings, in which- Figure 1 is a sectional view of our improved car-brake; Figs. 2 and 3, views of modified forms of the brake; and Fig. 4, a side view of a locomotive, tender, and car, showing-the arrangement of brakes and air-pipes.

Referring to Fig. 1, B is Vthe brake-cylinder, made in two halves, B1 and B2, in the form of truncated cones, secured to each other at their bases by bolts f, passing through flanges d e, the iiat end b of one cone, B1. being closed, while the end b of the other half ofthe cylinder is made open.

A is the piston, formed, in the present instance, of two rigid disks, a a, constituting the piston-head, to which the piston-rod D is secured. This piston A is of nearly. the same size as the flat head of the vacuum-chamber of the cylinder, but flts loosely within the latter.

The piston-head is connected with the cylinder by means of a sack, a', so as to completely exclude communication between the two halves ofthe cylinder. The sack a is secured to the piston-head by riveting the sack at c between the disks a a, a tight joint being similarly made where the sack is connected to the cylinder, about midway between its extremities, by bolting the edges ofthe sack between the flanges d c, as shown in Figs. 1 and 3.

In the modification, Fig. 2, the main portion of the cylinder is made of one piece, and the sack secured to about the center of the cylinder by the ring g, fastened by rivets f. The cylinder itself, however, is of substantially the saine form as that shown in Figs. 1 and 3 that is, the vacuum-chamber has sloping sides and a fiat head, b', the brake-cylinder being vof this form for the reasons explained hereinafter.

The piston-rod D is connected to the brake- .leversby a suitable system of levers, C F, as shown in Fig. 4. ln order to steady the action of these levers the piston-rod D may have an extension, D', adapted to move freely in a closed cap, E, in the head b of the cylinder, as shown in Fig. 3.

The outlet h of each cylinder communicates, through a system of pipes, with an ejector, airpump, or other suitable air-exhausting apparatus, so that on exhausting the air from the cylinder the pressure of the atmosphere on the piston A will cause it to assume the posi tion shown by dotted lines, so as to apply the brakes to the car-wheels.

Brakes having rigid cylinders or casings, as heretofore constructed, have been principally of two kinds-in one case apston adapted to slide in a cylinder being used, while in the other case a flexible diaphragm has been adapted to a casing of substantially spheroidal form. The objections to these' constructions are, that in the former case the friction on the piston and in the necessary stufingboxes greatly detracts from the power exerted by the atmospheric pressure, while in the case where a ilexible diaphragm has been used the rigid head of the piston-rod, on which only the atmospheric pressure could have any effective pressure, has been of toc small a size to be practically useful;

In our form of cylinder and piston the fric tion is reduced to a minimum, while the pecu liar form of the casing permits the use of the largest possible size of rigid piston on which the atmospheric pressure may act, while the piston and' sack adapt themselves to the slop'- ing sides and fiat head of the cylinder, thereof the pistons, so that the sack and its fastenings ymaybe relieved from undue strain in either position.

In reference to our improved arrangement of air-pipes, as shown in Fig. 4., practical ex- .perience has shown that where vacuum-brakes are used with the same system of pipes communicating with all the brakes throughout the train, the vacuum is first created in the brake-cylinder on lthe last car, while on the engine and tender (where the greatest impetus is) the brakes are not applied until a vacuum has been created in all the cylinders onthe cars in the rear. Consequently the impetus of the engine and tender drags the train some distance before itcan be stopped.

order tc avoid this difficulty we use one system of pipes and brakes for the engine and tender only, and Ian entirely separate system of pipes for the cars. l Referring toFig. 4, Gr is the ejector; B, the vacunm'orbrake-cylinder of one of the cars H, whileJ Bl yBI are the brake-cylinders of the engine I and tender K. Y d

A'lhe brake-cylinders of the cars H are connected with the ejector by a pipe, L, while the brake-cylinders B1 B1 of the engine and tender are connected to the same or a separate ejector by anotherpipe, L', separate from and independent of thepipe L. Hence, when the air-exhausting -apparatus is l'set in action, the brakes of the engine and tender will be at once applied with maximum efect, slightly before the brakes on lthe cars are applied, so

that the impetus of the heaviest part of thek train (the engine and tender) will be at once counteracted.

We do not desire to claim, broadly, abrakecylinder with a diaphragm; but

We claim as our inventionl. In a vacuum-brake, the combination of the cylinder, having an exhaust-outlet, sloping sides, and flat heads, with the piston-head A, of about the size of the head of the vacuumchamber, the said piston-head being connected tothe brakes by suitable levers, and to the cylinder by a flexible sack, u', secured there'- to about midway between the ends of the said cylinder, so that the piston and sack may rest on the head and sloping sides of the cylinder in each of the extreme positions vof the piston, all substantially as described.

2. The within-described system of brakes,

vcomprising one or lmore ejectors, a series of brake-cylinders, a set of pipes connecting an ejector with the brake-cylinderson the engine and tender only, Yand an independent set of pipes connecting any ejector with the cylinder on the cars, as and for the purpose set forth.

v In witness whereof we have signed our names to this specification in presence of two subscribing witnesses.

JOHN HARDY. v JOHN GEORGE HARDY.

Witnesses:

C. O. PAGET, .'l. BARTAL.

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