US1137576A - Automatic adjusting air-escape valve for railway-brakes. - Google Patents

Description

S. CHENEY. AUTOMATIC ADJUSTING AIR ESCAPE VALVE FOR RAILWAY BRAKES.

SAMUEL CHENEY, OF WICKEPIN, WESTERN AUSTRALIA, AUSTRALIA.

AUTOMATIC ADJUSTING AIR-ESCAPE VALVE FOR RAILWAY-BRAKES.

Listare.

Specification of Letters Patent.

Patented Apr. 2?, i9i5.

Application led November 23, 1914. Serial No. 873,577.

T0 zZZ whom t may concern:

Be it known that I, SAMUEL CHENEY, a subject of the King of Great Britain, and residing at Wickepin, Western Australia, Commonwealth of Australia, have invented certain new and useful Improvements in Automatic Adjusting Air-Escape Valves for Railway-Brakes, of which the following is a specification.

This invention has been devised to provide an automatically working appliance to be used in open communication with that portion of the pneumatic brake system known as the train pipe the object of the invention being that in case of emergency a sudden freeing of the air pressure may be accomplished so that the brakes may be quickly applied.

In order that my invention may be clearly understood the same will be explained with the aid of the attached drawing wherein the figure represents the invention in sectional elevation.

In apparatus embodying my invention which may be modified to suit varying working conditions of the train brake gear I employ a depending open cylinder as z the neck b of which interscrews with a T piece of the train air pipe. rIhe lower part of this cylinder a is internally screw threaded as at 0 so as of a sleeve cylinder Z thus forming two cylinders as a and Z the cylinder Z being open mouthed at its top end thus communieating with the upper and larger cylinder as L and providing a resultant and annular space as e between said cylinders.

In the interior cylinder Z are a number of air inlet holes f placed radially and giving free access with the said annular space e as shown. The cylinder cZ suitably connects by screw thread with the cylinder g which latter is of a lesser internal bore than that of the cylinder Z thus resulting in dierential areas for the respective pistons Z1 and g1.

The cylinder g is formed with radially arranged air exit holes y' opening to the atmosphere, said cylinder g at its bottom having a threaded neck lo whereby connection is made with the air reservoir 101. In the smaller cylinder g is a piston g1 carried on the bottom end of the tubular piston rod lg2 and said rod at its upper end carries the piston Z1 working in its cylinder d. The bore of the tubular piston rod g2 at its upper end is restricted to a suitable degree by a to interscrew with the bottom' small removable screw cap Z2 having a contracted orifice for the admission of air into the reservoir k1.

This invention makes provision whereby upon a suflicient release of air pressure in the train pipe the compound tandem pistons Z1 and g1 will move upward thus causing piston Z1 to uncover the air inlet ports f as shown by broken lines and so allowing air to escape therethrough and underneath piston Z1 and thence into the cylinder g and so by way of the exit ports 7' into the outer atmosphere. The object of the contracted neck Z2 in the top of the tubular piston rod is to provide a retardation of the air exhaust from the reservoir cl when a rapid reduction of air pressure takes place in the train pipe. This retardation of air exhaust allows a superior pressure to be exerted on the bottom face of the piston g1 and consequently causes the upward movement of both pistons and as soon as the air in the train pipe and reservoir has been fully exhausted the pistons will fall by gravity to the position as seeny in full lines in the drawing. When the train pipe is again charged the air will flow into the reservoir k1 through the contracted neck Z2 and tubular piston rod. The orifice in said neck Z2 is of an approved area to exhaust the air from the reservoir within suit the proper working requirements of the train brake gear as a whole. I may employ a spiral spring and interpose it between the piston Z1 and the underside of the neck o of cylinder a so that its expansive function may operate to press down said piston and assist in its fall by gravity when the air has fully escaped from reservoir k1 while on the upward stroke of the piston the spring prevents it from leaving its cylinder d.

What I claim as my invention and desire to secure by Letters Patent is 1. In air brake apparatus, an automatically acting air escape valve comprising a casing having a pair of cylinders of different diameters, the larger cylinder adapted to be connected to the train pipe and the smaller cylinder to an air reservoir, pistons working in said cylinders, and a tubular rod connecting the pistons and providing means for conducting air between the operative faces of the pistons, air vents being formed in the casing between said pistons, and the larger cylinder having ports in its wall ara given time limit and to ranged to be uncovered piston to admit the flow to said vents.

2. In airy brake apparatus, an automatically acting air escape valve comprising a by the respective pair of cylinders of different-diameters, the'k larger cylinder opening and closing the ports l therein in its movements, and a tubular rod connecting sald pistons'ln tandem and serving to feed air between thevtrain pipe. and

said reservoir.

3. In air'brake apparatus, the-combination of a pair of cylinders of different diamtrain pipeY K sion ports therein, v

said `pistons mtandem and providing air eters, the'cylinder of larger diameter having one. end/in communication With,I thetrainv pipe and also having ports in its side Wall to'admit air thereto from the train pipe,Y and the smaller cylinder having one end in :communication with an air reservoir andhaving air vent ports in its side Wall, pistons Working' in said cylinders, the piston in the larger cylinder controlling said air adminisand means connecting communication betWeenthe operative faces of the pistons. L

In testimony whereof I have hereunto set my. handin presence .of two-subscribing Witnesses.

SAMUEL CHENEY. Witnesses: f

RICHARD SrRRom SAMU-EL RINTEL.

, Copies of thisv patent may be obtained for five" cents each, by -addressing the'f Conimissio'nenof Patents Washington, D. C. Y

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