US1269478A - Fluid-pressure brake system. - Google Patents

Description

F. L. MARSTN. FlUlQ PRESSURE BRAKE SYSTEM.

APPLICATION man JULY 31, |916.

Patented June 11, 1918.

2 SHEETS-SHEET l.

I: s m viii m m F. L. MARSTON. FLUID PRESSURE BRAKE SYSTEM. APPucATsoN man JULY s1. 191e.

, 196mm@ mente@ June 11 1918.

ff I 54 w y pg@ v mf @fp M A NORA/EY.

FRANK L. MARSTON, OF PORTLAND, MAINE.

FLUID-PRESSURE BRAKE SYSTEM.

Specification of Letters Patent.

Patented J une lli, 11918.

Application lec'l July 31, 1916. Serial No. 112,276.

To all 'whom t may concern Be it known that I, FRANK L. MARs'roN, a citizen of the United States, residing at Portland, in the county of Cumberland and State of Maine, have invented certain new and useful Improvements in Fluid-Pressure Brake Systems, of which the following is a specification.

My invention relates to improvements in fluid pressure braking systems in which automatic devices, known as triple valves are used.

The objects of my invention are, rst: to eliminate the shock and jar to passengers on a moving train, second: to eliminate the danger of derailing one or more cars in a moving train upon a curve: third, to decrease the wear and tear on the rolling stock and the strain on the braking apparatus all of which are caused by the sudden, complete and automatic application of the brakes to full emergency position upon the accidental breaking or pulling apart of the train hose, as occurs in the systems at present in use.

l attain these objects by a combination ofpistons and valves attached to and working with the triple valve of the present systems. Said combination is shown in the accompanying drawings and hereafter de scribed as applied to the Westinghouse quick acting triple valve, as used in air brake systems. But I do not restrict my claims to a combination applicable to a quick acting triple valve, nor to the lVestinghouse apparatus, nor to the exact construction as rep resented in the accompanying drawings or following description,-\vhich is applicable to Westinghouse apparatus only, but have represented it as thus applied to more fully describe the working parts and the result of their action.

No change is made in the l/Vestinghouse triple valve in any of the parts thereof, eX- cepting in the graduating stem, the old plug which screws into the opening X at the end of the stem being taken out, and a new plug, embodying all the features of my combination, being screwed into the aforesaid opemng.

This combination, shown as a whole, and in connection with the general form of the Westinghouse quick acting triple valve, in Figure l, which shows all working parts in release position, consists essentially of two castings 20 and 23, which constitute the shell or main body and contain the working parts. These castings are held together by flange bolts and the joints are made air tight by gaskets clamped between the castings.

Fig. l is a vertical section of the combination of the Westinghouse triple valve as usually shown in the descriptions of the same, together with my improvements, show-- ino' their working parts.

Fig. lA is a horizontal section of the bot-` tom part of the casting 23 with the contained parts taken on the line w-y in Fig. l, and u-fv in Fig. 2, showing the valve seat 7" with its port openings. A bottom view of the slide valve 36 is also shown with its recess s and a portion of the rod 26.

Fig. 2 is a view of the inside of 23 with the flat ring 35 removed to show the pas sage e.

Fig. 3 shows a vertical section of my improvements together with a small portion of the Westinghouse parts, being a part of Fig. 1, shown in the emergency position but on a larger scale.

Fig. 3A is a horizontal section taken through the center of the rod 21 showing a portion of the same passing through the sliding collar 37 and the ring c which is held in place by a pin passing through the rod and ring.

Fig. 3B shows a horizontal section through the center of t-he piston 27, sliding ring 30, the lock nut 28, and a part of the rod 26, showing the pin passing through the rod and nut. The top of the slide valve is shown with a part of the ianges removed to show the pin which holds the spring 25.

Fig. l is a vertical section of the lower part of Fig. 3 in automatic emergency pesition, and Fig. 4A is a View of 7c. 37, and a part of 21 in connection with the l/Vestinghouse parts in the same relative position.

0n account of the small scale of the drawing as shown in Fig. l, and consequent ditiiculty of lettering the same, I hereby, in the following description, refer to the detailed views as well as the general view which is depicted in Fig. l.

The large iston in the chamber CZ', having the same iameter as piston 5 in the present Westinghouse triple valve, is rigidly attached to the rod 2l which passes through the stem of the threaded plug 'forming a part of 20, and a movable shoulder 37 engages one end of a spring 22.

A. piston 27 in chamber e is held rigidly against a shoulder on the rod 26 by a nut 28. A spring 29 resting against one face of the piston 27 holds a movable washer 30 against a shoulder on the rod 26, which passes through the spring 29.

.The rod 26 is loosely attached to a slide valve 36 moving in the chamber r. All chambers containing pistons or valves are brass lined.

The chamber r is connected with the pressure chamber H by a small pipe screwed into a threaded opening in chamber 9". The size of this pressure chamber should be governed by the size of the auxiliary reservoir connected with the chamber of the triple valve proper, and should be so proportioned that the port a would not exhaust the pressure too rapidly into the train line when the same is accidentally opened or broken. The object of this second auxiliary reservoir is, first: to receive the compressed air from the train pipe and supply the same to the chamber CZ to resist any movement to the right of the piston 211. Second: to sup ply a propelling force to the piston 27 with its controlling valve 36 when the pressure in any manner is reduced in the chamber e.

The tension of the spring 32 which rests in the plug 33 and against the shoulder 3l on rod 26 is equal to a pressure on the face of the piston 27 of about 10 pounds to the square inch and can be graduated to correspond to the limit of service reduction desired by the plug 33 which is locked in the required position by a lock nut 34:.

The tension of] the spring 29 resting 'against the piston 27, and the sliding vcollar 30, is equal to the pressure of about l0 pounds to the square inch on the face of the piston 27, or about the difference between the reduction of service and the rey duction of emergency.

In the release position of the device, shown in Fig. l, the piston 5 is against the shoulders at the extreme left, the slide valve 3 is at the extreme left, the port opening e is closed by the bottom of the chamber, the recess n connects the brake cylinder port fr with the exhaust port P allowing the brake springs to hold the brakes at release. The piston 27 is held at the extreme right by the tension of the spring 32; the recess s in the slide valve 36 is over the exhaust port 7L. The pressure in the train line passes in at A, e. g., past the piston 5 by the groove z' to the chamber m and the auxiliary reservoir B, raising the pressure in this reservoir to that of the train line, also 'from the train line A, e, a, a to the chamber el', and a to the chamber o', by the groove a to the chamber r and the pressure chamber H and mesme by port f passage e e to the chamber el equalizing their pressures with the train line.

The service action used in ordinary stops is the saine in the original `Westinghouse parts as it is in the present arrangement. There is no action n the new partsmy combination. The spring 32 revents any motion in the piston 27 by holt ing it to the extreme right with a force strong enough to overcome the counter force caused by the ordinary service reduction of pressure in the chamber 0. The pressure in the chamber cl remaining nearly the same, would be slightly higher than that in m, which slightly expands when piston 5 moves to the right. The projection j striking the rod 2l attached to the piston 24E prevents any further motion of the piston 5: the action of service and release continues as in the present arrangements.

The emergency action is caused by the engineer throwing his valve lever into emergency position, and is the same in the West inghouse parts as in the present arrangements. In the new parts which are einbodied in my invention, the following action takes place: theair in the train line is reduced between l0 and 2O pounds to the square inch by the said action of the engineer, causing the air to flow by the ports a e, etc., to the train line from the chamber 02 until pressure in both are equal. Then the pressure in the chamber r and the pressure chamber H being so much greater than that in 0, forces the piston 27 with the slide valve 36 to the let, overcoming the tension of the spring 32 until the collar 30 rests in the recess m; the tension of the spring 29 then coming into ellect prevents any further movement of the piston 27 and the slide valve 36 which is now in such a position that the recess s connects the exhaust port It with the port f allowing the air to' escape from the chamber d by way of passage c c f s to the exhaust port L until the pressure in the chamber cl is the same as that oi" the atmosphere, when the piston 5 drives the rod 21 and the piston 2a to the extreme right, overcoming the tension of spring 22 as it does in the present arrangement. LThe various parts will then be in emergency position as shown in Fig. 3.

The position ol the various Westinghouse parts and their action is the same as in the present arrangement. The action of rele: se in the lVestinghousc parts is the same as in the present arrangement.' The action oi' release in the new parts is as follows:

The pressure being raised in the train line through the engineersvalve, flows in by the passage c e a a to the chamber' o raising the pressure to a point slightly higher than that in the chamber r, allowing the spring 32 to force the piston 27 to the and piston 24 extreme right, returning it with the slide valve to their former positions, and allow ing the air in the chamber 1^ and pressure chamber H to flow by the port f and passage e e to the chamber cZ, returning the piston 24tand the rod 2l to then' former positions, when it again flows into the chamber r by the groove n raising the pressure in the pressure chamber H to that in the train line.

The automatic emergency action is caused by the breaking or pulling apart of the train hose. The air in the train line is exhausted to atmospheric pressure almost instantly. Pressure in 0 exhausts by train line and passage e e u a to atmosphere, allowing the pressure in 7 which is nearly as high as formerly, to torce piston 27 rapidly to the extreme left, overcoming the tension of both springs 32 and 29 and causing the slide valve 36 to rapidly pass the emergency position allowing but a slight reduction of pressure in chamber d by passage e e and port f to exhaust port It while recess s is passing over them, allowing piston 5 to force rod 21 and piston 24 to the right until the shoulder lc on rod 2l strikes the collar 87 when the spring 22 resists further motion. The slide valve t now covers the exhaust port t and the recess s connects port f with recess p allowing the pressure in chamber r t0 pass to chamber eZ under the edge of 36 by recess p s port f and passage e e, again raising the pressure in el to that in the second pressure chamber H. Now the pressure in the auxiliary B has exhausted into the brake cylinder to a point slightly lower than that in the pressure chamber H, and the higher pressure in the chamber ci forces the piston 2e to the left, driving with it the rod 2l and the pistons 5 and 7 until piston 7 closes the port w in slide valve 3 preventing further discharge of air into the brake cylinder until the air in the chamber d and pressure chamber H exhausts by the port a to a point slightly loweil than that in the chamber m and the auxiliary B, when the piston 5 will again be forced to the right driving rod 2l with it until again checked by the spring 22, when the piston 24C again covers the port a preventing further eX- haust of air from chamber d and pressure chamber H until the pressure in m again exhausts by the port fw which has in the 4mean time been opened to the brake cylinder. This operation continues to take place until the pressure in the brake cylinder is the same as that in both chambers. Then, all exhaust ports being closed, the brakes remain set until the pressure in the train line has again been raised, or the air lealrs out oi both the auxiliary reservoir B and the brake cylinder as in the present arrangement.

1t can be readily seen that this repeated opening and closing orp the port w in the slide valve 3 `causes gradual application of the brakes in the automatic emergency stop, thus accomplishing the objects set forth in the beginning of my description.

What l claim my invention and wish to secure by Letters Patent is the following combination of pistons and valves when applied to triple valves of Huid pressure braking systems:

l. Means for cushioning the operation of a brake valve comprising a casing having two chambers normally comminiicating with each other at points spaced from each other, one chamber having an exhaust port, a piston movably mounted in the other chamber, means fornormally holding the piston at an initial position, means for applying uniform pressure at the opposite sides or' the piston when at its initial position and at rest, the said communications between the chambers being so arranged that the pressure in both chambers is normally uniform, a valve movably mounted in the chamber having' the exhaust port, a piston movably mounted in the last mentioned chamber between the communications connecting the chambers and connected with the valve, resilient means for holding the last mentioned piston at a normal position and the valve at a closed position over the port and means adapted to coperate with the rst mentioned piston after the beginning of its movement and before the end thereof to interrupt the passage of the pressure in that chamber in which it is located and thereby disturbing the balance of the pressure in the ported chamber whereby the piston therein moves the valve to an open position with relation to the port.

2. Means for cushioning the operation of a brake valve comprising a casing having two chambers normally communicating with each other at points spaced from each other, one chamber having an exhaust port, a piston Inova-bly mountedin the @other chamber, means for normally holding the piston at an initial position, means for ap plying uniform pressure at the opposite sides of the piston when at its initial position and at rest, the said communications between the chambers being so arranged that the pressure in both chambers is normally uniform, a valve movably mounted in the chamber having the exhaust port, a piston movably mounted in the last mentioned chamber between the communications connecting the chambers with the valve, resilient means for holding the last mentioned piston at a normal position and valve at a closed position over the port, the last said chamber being provided with a groove which establishes communication with the opposite ends of the chamber and at the opposite sides ot the last said valve when the same is at one of its positions, and means adapted to cooperate with the irst mentioned piston after ithe beginning of its movement and before the end thereof to interrupt the passage of the pressure in that chamber in which it is located and thereby disturbing the balance of the pressure in the ported chamber whereby the piston therein is moved beyond the groove and moves the valve to an open position with relation tothe port.

3. In a device as described, a easing having a chamber and provided with an eX- haust port, there being inlet ports communieating with the chamber at points spaced from each other, a piston movably mounted in the chamber between the inlet ports, a rod Xed in the piston, a spring mounted on the rod at a point between the ends thereof and adapted. to encounter the easing when the rod is moved and exert. pressure upon the rod, a spring interposed between the rod and casing to hold the rod at a normal pof sition therein, a valve carried by the rod and normally closing the exhaust port, the parts being so arranged that the initial movement of the rod compresses the last mentioned spring and moves the valve to an open position over the exhaust port, and

the linal movement of the rod compresses .A

the first mentioned spring and moves the valve to a closed position over the exhaust port.

In testimony whereof l my signature.

' FRANK L. MARSTON Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C.

Images