US739761A - Fluid-pressure brake for railway-trains. - Google Patents

Description

- No. 739,761. PATENTED SEPT. 22, 1903. I

J. E. VOORHEES.

FLUID PRESSURE BRAKE FOR RAILWAYIRAINS.

APPLICATION FILED DEG. 5, 1898.

H0 MODEL.

nections.

UNITED STATES Patented September 22,1903.

PATENT OFFIC JEREMIAH F. VOORHEES, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TO NATHANIEL B. -K. HOFFMAN, OF NEW YORK, N. Y.

FLUID-PRESSURE BRAKE FDR RAILWAY-TRAINS.

STE EC'IFIGATION forming part of Letters Patent No. 739,761, dated September 22, 1903.

Application filed December 5 1898. P Serial No. 698,888. (No model.)

To all whom it may concern.-

Be it'known that I, JEREMIAH F. Voca- HEEs, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvauia,have invented a new and useful Improvement in Fluid-Pressure Brakes for Railway-Trains, which improvement is fully set forth in the following specification, reference being had to the accompanying drawings, in which similar characters of reference indicate similar parts.

My invention relates to an independent controlling device for automatic fluid-pressure brakes described in my Patent No. 615,326, bearing date December 6, 1898.

In the present improvement I substitute an improved relief-valve mechanism in connection with the brake-cylinders for that described in said patent, and I add to the locomotive equipment an auxiliary storage-reservoir and an automatic pressure-valve for the purpose of enabling the auxiliary trainpipe forming part of said controlling device to be charged with fluid-pressure without the same being takendirectly from the main reservoir when it is not expedient to do so.

The usual connections of an automatic brake apparatus such as now ingeueral use being so well known they are not illustrated.

In thedrawings', Figure 1 isa diagrammatic side elevationshowing the several parts of my improved controlling device and their con- Fig. 2 is a plan view of the engineers valve (3 in section. Fig. 3 is an enlarged vertical section of the variable reliefvalve mechanism F, and Fig 4 is an enlarged vertical section of the pressure-valve A.

The valve Aisinterposed between the main reservoir (not shown) and an auxiliary storage-reservoir A, which is connected with an auxiliary engineers valve 0 through a pipe B and a pressure-reducing valve B, which may be of ordinary construction and adapted to limit an accumulation of pressure in the pipe B, as may be desirable.

The valve 0 is an ordinary three-way cock connecting the auxiliary train-pipe D with the supply-pipe B or with the atmosphere, an intermediate position of the plug-valve G blanking all ports. A gage I, situated on the locomotive, enables the engineer to be accurately informed as to the amount of pressure he admits to or releases from the pipe D through the valve 0.

The auxiliary train-pipe D extends throughout the train and is connected by a branch pipe D at each car with a variable relief-valve F for the brake-cylinder H.

It is now common to maintain a greater pressure in the main reservoir than in the main-train-pipe of the usual automatic brake apparatus, and this extra pressure can be used for charging the auxiliary train-pipe D without inconvenience, for the fact that the automatic valve A will prevent the pressure in the main reservoir from beingthereby reduced to an extent that would cause a return of fluid-pressure thereto from the main trainpipe, and the pressure stored in the auxiliary reservoir A will insure sufiicient pressure in the pipe D when needed, A partition A in the valve-casing A forms a'seat for a valve A which is connected to a. piston A within a cylinder forming part of the valve-casing. A flexible gasket A is interposed between the piston and a plate A"'. Its outer edge is secured on an ofiset by the annular flange of the screw-cap A A spring A", interposed between the plate A and a regulating-stud A acts to retain the valve A on its seat.

The piston A is? subject at all times to the main reservoir-pressure, which acts on the piston in direction to open the valve against the resistance of the spring and allow the fluid-pressure to pass from the main reservoir to the reservoir Apand the regulating-stud enables the resistance of the spring to be ad justed to close the'valve when the pressure in the main reservoir does not exceed an amount usually employed in the main trainipe. p The valve-easing F is divided into separate compartments by an actuating-diaphragm F, the outer edge of which is secured on an 0&- set I5 by the annular flange of the screw-cap 5 F. A plate F and a cylindrical guide-block F fitted into the tube F forming part of the screw-cap F are,with the diaphragm,seoured on a smaller end of the valve-stem by means of a nut F Into the lower end of the tube 10: F is fitted a regulating-stud F and between it and the guide-block F is interposed a spring F". A cap F serves as a lock-nut for the regulating-stud. The interior of the screwcap issubject to pressure in the auxiliary train-pipe D, to which it is connected by the branch pipe D. The main body of the valvecasing is open to the atmosphere to an extent that-will prevent an appreciable accumulation of pressure therein. A chamber F is in constant communication with the brakecylinder through the pipe E. A valve F which may form part of the stem F or be separate therefrom, at the option of the constructor, is adapted to form a tight joint with an annular seat F by means of a gasket F secured to the face of the valve by means of a nut engaging with a thread on a larger part of a stem F which is rigidly connected to the valve and extends into a central hole in a perforated bridge E", which acts as a guide for it.

From the fact that the space between the relief-valveand the diaphragm F is open to the atmosphere their relative areas determine a proportionate efficiency of pressure in the auxiliary train-pipe D to retain pressure in the brake-cylinders in excess of an amount retained the-rein by the action of the reliefvalve springs in a manner similar to that described in my prior patent, and the pro portion may be at the option of the constructor; but to obtain the best results it should be such that the maximum pressure employed in the pipe D need not exceed an amountjust sufficient to admit of graduation.

The amount of clearance between the plate F and the annular end of the tube F should not exceed one thirty-second of an inch when the valve is seated, thereby preventing the valve from forcibly striking its seat when there is a sudden reduction of pressure in'the brake-cylinder, and the opening through the valve-seat F should be proportioned to re: lease pressure from the brake-cylinder H as rapidly as admitted thereto through the triplevalve mechanism and pipe G with this amount of clearance of the valve from its seat.

The relief-valve springs should be uniformly adjusted to retain in the brake-cylinders a pressure that will exert a braking force proportionately less than the weight of the car when stationary. 1

Limitation in'the amount of fluid-pressure stored in the auxiliary reservoirs ofthe usual car-brake apparatus is unnecessary when my controlling device is employed, for the fact that said stored pressure cannot then become efiective as a braking force in excess of an amount determined by the adjustment of the relief-valve springs unless so determined by the engineer from the locomotive of the train and cannot exceed to an appreciable extent the amount so determined. A suffi-.

cient pressure should therefore be maintained in the auxiliary reservoirs to apply the brakes with the greatest amount of force that can be advantageously employed at any time.

can be automatically applied predetermined by the engineer according to the amount of pressure he permits to accumulate in the auxiliary train-pipe D.

The engineer is by means of my controlling device enabled to positively regulate the braking force according to the speed of the train and atmospheric conditions afiecting the adhesion of the wheels to the rails. He can also cause a reduction in the amount of pressure in the brake-cylinders when it exceeds a specific amount by releasing the pressure from the auxiliary train-pipe D through the valve 0 and with great rapidity on account of the small volume of fluid-pressure necessarily released from the auxiliary trainpipe in order to enable the relief-valves to al most instantly reduce the pressure in the brake-cylinders a proportionately greater amount.

The engineer can control a reduction in the force with which the brakes are applied in the manner described whatever may cause the brakes to be applied, excepting the train parting. Should this occur after the auxiliary train-pipe has been charged and quick-acting triple valves are employed, the serial action of the brakes will be more rapid than the entire release of pressure from the auxiliary train-pipe at place of parting, and the pressure therein will for a short length of time act to retain an extra pressure in the brake-cylinders and aid in stopping the train.

In case of the brakes being automatically applied from any cause when there is no pressure in the auxiliary train-pipe the pressure admitted to the brake-cylinders in excess of an amount sufficient to overcome the resistance of the relief-valve springs escapes to the atmosphere through the relief-valves as rapidly as it enters the brake-cylinders' The maximum force with which the brakes can be automatically applied is therefore primarily determined by the resistance of the relief-valve springs and cannot exceed this amount unless the engineer admits pressure relief-valve to increase the load of said valve,

this being the general nature of my invention as set forth in my prior patent previously referred to.

The present improvement eliminates the risk of the brakes being automatically applied on account of charging the auxiliary trainpipe while the train is moving and, further, increases the efficiency of pressure in the auxiliary train-pipe without increasing the area of the relief-valve to an undesirable, extent. Iconsider all known substitutes and equivalents as within the scope of my invention.

I claim as my inventionv and now desire to secure by Letters Patent- 1. In a controlling device for fiuid-pressur brakes, the combination of a main storagereservoir, an auxiliary storage-reservoir, an automatic valve controlling a connection be- 7 tween said reservoirs, and a pressure-reducing valve for limiting a flow of pressure from said auxiliary storage-reservoir to an auxiliary train-pipe, substantially as specified.

2. A valve-casing containing a relief-valve interposed immediately between a brake-cylinder and the atmosphere, a piston or diaphragm, one side of which is exposed to the atmosphere the opposite side being subject to fluid-pressure in an auxiliary train-pipe, and a stem or red interposed between said relief-valve and piston or diaphragm, substantially as specified.

3. A valve-casing having a connection to an auxiliary train-pipe and another to a brakecylinder, and an intermediate compartment open to the atmosphere, a relief-valve opening from a brake-cylinder to said intermediate compartment, a piston or diaphragm interposed between said compartment and an auxiliary train-pipe, a stem or projection connected with said diaphragm or piston, and adapted to engage with said relief-valve, a spring acting in concert with fluid-pressure acting on said piston or diaphragm, to cpunteract pressure in a brake-cylinder, acting to open the relief-valve, substantially as specified.

4. A valve-casing having a piston or diaphragm fitted therein, one side of which is subject to pressure from a retaining-pipe while the opposite side is exposed at all times to the atmosphere, a stem or projection con- .seat acts on the valve in direction to unseat it, the opposite side of the valve being exposed at all times to the atmosphere and the proportion of the area of the valve subject to pressure from the brake-cylinder to that of said diaphragm or piston, subject to pressure from said retaining-pipe, determining the effectiveness of said pressure to retain the valve on its seat substantially asspecified.

5. In a fluid-pressure brake apparatus, the combination with the brake-cylinders and a main fluid-pressure supply, of a pressure-retaining valve A, storage-reservoir A, pressure-reducing valve B, supply-pipe B, ongineers valve 0, auxiliary train-pipe D, and an automatic variable re1ief-valve F, adapted to vent excess pressure immediately to the Witnesses ARTHUR KROSSMANN, AARON HOFFMAN.

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