US147338A - Improvement in hydraulic car-brakes - Google Patents

Description

'NrTnn STATES THOMAS MCBRIDE, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN HYDRAULIC CAR-BRAKES.

Speeiication forming part of Letters Patent No. 147,338, dated February 10,1874; application filed October 13, 1873.

To all whom 'it may concern:

Be it known that I, THOMAS MGBRIDE, of Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in H ydraulic Car-Brakes, and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being had to the accompanying drawings, which form part of this specication, in which the figure shown is a representation of a vertical longitudinal section of my invention. l

This invention has ,relation to hydraulic car-brakes; and consists in the combination, withthe conveying-pipes leading from the water-tank or tender and locomotive-boiler, of a glycerine tank or reservoir, having communication with the pipe leading' from the boiler by means of a tube provided with a suitable valve, all as and for the purpose hereinafter described.

Referring to the accompanying drawing, A is a locomotive, of which B is the boiler, and C a tender. D is the conveying-tube, passing from the boiler to and beneath the tender and cars, having suitable devices for coupling and uncoupling, and so arranged that the contents of the tube will be held in place whether the sections be united or apart. E represents one of the cylinders through which hydraulic pressure is exerted to operate the brakes, said cylinders being provided with pistons, as shown, so connected to the brakes that as the pistons are forced out the brakes are applied to the wheels. A spring, H, is employed to retract the brake andV piston after the hydraulic pressure is Withdrawn. I represents a tube leading from the water-tank in the tender to the tube D, a three-way valve, K, being located at the junction of said tubes, from which leads to the boiler belowT the water-line a pipe, L.

The operation is as follows: The valve K is rst opened in such manner as to allow the water from the tender to enter and ll the tube D, passing thereto through the pipe I,

and kept in this position until it is desired to apply pressure. The valve K is then turned, cutting off communication with the tender, and opening it with the boiler, whereupon the boiler-pressure is at once brought to bear upon the water in the tube, forcing the pistons out and applying the brakes to the wheels.

The object of my invention being to avoid the danger of the water freezing in the tube D in cold weather, I provide the following arrangement of devices: A tank, M, containing glycerine or other non-freezing liquid, is pro, vided and placed in communication with the tube D by' means of a pipe, m, having a checkvalve, m. To apply the glycerine to the operation of the brakes, the check-valve m is opened and the liquid allowed to tlow from the tank :into the tube D until the latter is filled all the way from the three-way cock to the brake-pistons. The three-way cock is now turned, opening communication with the boiler. Pressure' is obtained which at once closes check-valve m', preventing flow of glycerine from tank. The column of glycerine in tube D is moved along in the direction of the cylinders under cars by pressure from boiler, so that'the end of said column adjacent to cock K will travel as far, say, as the tube m. The vacuum which will be formed between the latter and the three-way cock will be filled by the water rushing through said cock. Vhen the pressure is relaxed, by turning cock K, the water in tube D from, say, the cock K to the pipe m will pass up the pipe I, leading to tender, and the glycerine column will assume its original position. Thus there will be no glycerine returned to the boiler or tender, for the water and glycerine will not be mixed in the tube D. The glycerine simply moves to and fro, and the water that enters tube D from boiler is pushed into tender on the return motion of the glycerine column.

I herein disclaim the pipes I, L, and D, and

the three-way valve K, combined as shown,

the same having been described and claimed in an application led by me July 2, 1873, now pending.

I-Izwing fully described my invention, what I with said pipe L by means of the pipe m and claim as new7 and desire to secure by Letters valve m', 'as shown and set forth. Patent, is- In testimony that I claim the foregoing I rIhe combination7 with the conveying-tube have hereunto set my hand this 30th day of D and pipes I and L, the latter eommuni- September, 1873. eating with the boiler B in order to obtain Vitnesses: THOMAS MGBRIDE. hydrzniliepressnre,as setforth7of the giyoerine M. DANL. GONNGLLY, teni; or reservoir M having communication EUGENE I?. EADSON.

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