US536484A - Tony silvene - Google Patents

Description

(No Model,)

i T.l SILVBNE. Y AUTOMATIG'BRAKE MBGHANISM. No. 536,484.

.Patented Mar. 2.64,* 1895.

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NITED STATES PATE-NT OFFICE. I

TONYSILVENE, OF VICTORIA, CANADA.

AUTOMATIC BRAKE MECHANISM.

SPECIFICATION forming part of Letters Patent No. 536,484, dated March 26, 1895. Application iled October 20, 1894:. Serial No. 57261430. (No model.)

To all whom it may concern,.-

Be it known that I, TONY SILvENE, a citizen of France, residing at Victoria, British Columbia, Canada, have invented certain new and useful Improvements in Automatic Brake Mechanism; 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 towhich it appertains to make. and use the same.

The purpose of the present invention is the provision of a relief valve for the air cylinders of automatic brake mechanism, which will be self acting and quickly respond to the variation in pressure of the air in the train pipe, so as to quickly relieve or bleed the clyinder when it is desired to release the brakes so that the latter will be quick in their releasing action.

With these ends in view the invention consists essentially of a release valve, embodying in its construction two pistons of differential areas, comprising between their oppos, ing ends a chamber which is inncommunication with the train pipe, the smaller piston closing two passages, the one leading to the brake cylinder, the other to the' outer air.

The improvement consists essentially of the novel features and the combination of the parts which hereinafter will be more fully described and claimed and which are shown in the annexed drawing, which is a vertical central central section of a valve constructed-in accordance with and embodying the essential principles of the invention.

The valve case is composed of two parts 2 and 3, which are secured together'by bolts or other fastenings, passingthrough the opposing flange ends. The upper part 2, is closed at the outer end, which end is centrally apertured and internally threaded to receive a set screw, 4. The lower part, 3, is provided with a nipple a, by means of which communication is had with the brake cylinder and with a lateral opening,b, which makes connection with the train pipe, B. The upper vpart of the bore of the part 3 is larger than the lower part of the said bore and between the two 'is provided a chamber C, which is aboutopposite the opening, b. Two pistons, E and D, are connected or form part of a valve stem 5, which latter is projected into the chamber formed in. the part 2, and receives a coiled spring 6, which is confined between the pisdton E and a ianged nut 7, held in engagement with the inner end of the set screw 4. The two pistons D and E are in axial yalignment and it steam tight within their respective bores.

The passage 8 is provided in the nipple and communicates with the brake cylinder, but extends vertically through the lower portion of the part 3 and communicates with -an annular chamber 9. A relief passage l0 leads from the chamber 9 and is designed to carry off the spent air from the brake cylinder when it is desired to release the brakes. The piston D is constructed to close the passages 8 and 10 at the proper time, so as to prevent the escape of the air when the brakes are applied.

The operation ot' the invention is as follows: The opening b, as herein stated, is connected with a train pipe, the air pressure within which is usually about seventy pounds. The set screw 4 is adjusted to create aforward pressure on the piston E, through the spring 6, of say, about twenty pounds. Under normal conditions the upward pressure on the piston E is about 61.85 pounds and on the piston D, plus the twenty pounds pressure of the spring 6, sixty pounds. Hence it will be seen that the upward pressure is in excess of the downward pressure by about 1.85 and therefore the pistons E and D will occupy the highest position, leaving the passages 8 and 10, open. On the application of the brakes the pressure in the train pipe is reduced and the upward pressure on the piston E will be about 53.01 and the downward pressure on the piston D, 35.24 plus twenty pounds, the pressure of the spring, or a total of 55.24 pounds. It will be seen that the downward pressure exceeds the upward. Hence the'pistons Will move downward and close the passages 8 and 10, during the time that the brakes are applied. When the pressure in the train pipe assumes its normal condition the upward pressure will again exceed the downward pressure and the pistons D and E will quickly reverse their position and uncover the passages 8 and 10 and permit the bleeding of the brake cylinder.

It will be observed that the valve is wholly munication with the train pipe, two passages,

the one communicating with the brake cylinder, the other with the outer air and controlled by the smaller of the two pistons, and a spring similarly exerting a pressure to close the piston and cut off the communication between the said two passages, substantially as set forth.

2. The herein shown and described release valve for the cylinders of automatic brake mechanism, comprising a valve casing, diierental pistons operating in said casing and having a chamber between their opposing ends, which is at all times in communication with the train pipe, an annular chamber surrounding the lower portion of the smaller piston and two passages extending therefrom, the one adapted to communicate with the brake cylinder the other leading to the outer air, a coiled spring located in the upper portion of the Valve casing and surrounding the valve stem, and a set screw, passing through a threaded opening in the upper end of the valve casing and adapted to regulate the tension of the said coiled spring, substantially as described.

In testimony whereof l have signed this specification in the presence of two subscribing witnesses.

TONY SILVENE.

Witnesses:

JAS. H. MANSELL, J. CATHCART.

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