US503244A

US503244A - Air-brake valve

Info

Publication number: US503244A
Authority: US
Publication date: 1893-08-15
Anticipated expiration: 1910-08-15

Description

- (No Model.)

' H. M. LOFTON.

AIR BRAKE VALVE.

, -No.50s,244. Patented Aug, 15, 1893.

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Hf OFTON. Am; B AL E, No. 503,244. ,Piatented Aug. 1-5, 1893;

(No Model.)

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AIR BRAKE VALVE. No. 503,244. Patented Aug. 15, 1893.

WM. I

U ITED STATES PATENT OFFICE.

HERBERT M. LOFTON, OF SAVANNAH, GEORGIA.

Al R-BRAKE VALVE.

SPECIFICATION forming part of Letters Patent No. 503,244, dated August 15, 1893.

Application filed August 29, 1891. Serial No. 404,118. (No model.)

To all whom it may concern.-

Be it known that I, HERBERT M. LOF'ION, of Savannah, in the county of Ohatham and State of Georgia, have invented certain new and useful Improvements in Air-Brake Valves; and I do hereby declare thefollowing 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 the same, reference being had to the accompanying drawings, and to letters and figures of reference marked thereon, which form a part of this specification.

This invention relates to the class of valves that are used by locomotive engineers in applying and releasing air-brakes, the object being to improve the construction to the end that they be made more convenient and certain in their operation.

The invention consists of valves and passages and means for operating the valves the particulars of which will be hereinafter fully described and the details of which are all shown in the accompanying drawings, in

which- Figure 1 is a vertical section on the line 1-1, Fig. 2, and shows the inlet and outlet ports and two puppet-valves one of which is integral with, and is opened and closed by, a piston, while the other is opened by the piston and closedby gravity. This figure also shows an oscillating disk valve and the means for operating it. Fig. 2 is a top view of the casing with the cover and the oscillating valve and the mechanism for operating the oscillating valve removed. Fig. 3 is a central vertical section on the line 3 Fig. 1, showing the valve-seats and the discharge openings through which released air is discharged into the outside atmosphere. Fig. 4 is a horizontal section on line 4., Fig. 1, showing the oscillating valve in the position that will cause the train-pipe, and its connections to be charged arbitrarily, that is without the air passing through the valves that automatically regulate the pressure. In the above figure and in all the figures showing the different positions of the oscillating valve, the open 'ports in said valves are shown by solid lines, 5

in the valve coincide with the ports in the valve seat. Fig. 5 shows the oscillating disk valve in the position that will charge the air through the train. pipe automatically, the pressure in the train pipe being regulated by the valves shown in Fig. 1. Fig. 6 shows the oscillating valve in the position that will close all the ports that is to say none of the ports in the seat will coincide with the open ports in the valve and the pocket ports in the valve will not connect any two of the ports in the seat. Fig. 7 shows the oscillating disk-valve in the position that will cause one of the pocket-ports in the valve to connect the two ports in the seat that will cause the release of the air in the train-pipe automatically. Fig. 8 shows the oscillating valve in the position that will cause a pocket-port in the valve to connect the two ports that will cause the air in the train-pipe to be released positively, that is without passing through the-other valves. Fig. 9 is a section through the oscillating disk-valve on the same plane as the section through the valve casing in Fig. 1. Fig. 10 is a plan of a portion of the cover shown in Fig. 1, showing the notches that hold the operating-lever in its different required positions.

In the several figures the difierentparts are uniformly marked by reference characters.

The casing consists of the main part A and the top cover B and bottom cover 0. The part A carries the inlet port land the outlet port 2. The inlet port connects with the air supply and discharges above the valve 3, which is an oscillating disk-valve having open portst and 5 through-it, vertically, and pocket ports 6 and 7 that are of a length that will connect the two of the ports in the seat. The ports in the seat (see Fig. 2) are the ports 8 (also shown in Fig. 1) through which the air passes to automatically charge the train pipe and its connections, the port 2, (also shown in Fig. 1) through which the air passes to arbitrarily charge the train-pipe and its connections, the

ports

9 and 10, (shown in Fig. 3) through which air is discharged to reduce the tension in the'train-pipe. These ports in the seat are also shown, mostly by dotted lines in Figs. 4, 5, 6, 7 and 8. The piston 11 works, vertically, in the cylinder 12 and carries a puppet-valve that has its seat in the part A of the casing. The pilot of a valve 13 abuts against the pilot of a valve 14 that is made integrally with the piston 11 as shown in Fig. 1; the two valves having abutting pilots of such a length as will prevent both being closed at the same time, fora reason that will hereinafter be explained. The piston 11 is forced downwardly by a spring 15 of a strength and for the purpose that will also be described. Aport 16 opening into the chamber above the oscillating valve connects that. chamber with the cylinder 12 below the piston 11. The lug 17 on the bottom cover prevents the depression of the piston below the opening of the port 16 into the cylinder 12. A port 18 connects the cylinder 12, above the piston with the outlet port 2. The oscillating disk valve 3 has a pilot 19 that goes down into an opening in the part A to cause the valve to keep a central position on the seat. The valve 3 is moved back and forth by a lever 20 that is attached to the stem 21 of the valve by a tongue 22 working in a suitable groove in the boss 23 011 the valve. The valve and stem are made in two pieces to allow the valve to seat itself freely. Several notches 24, 25-, 26, 27 and 23 are made in an annular projection on the cover B in which the springpawl 29 goes to hold the valve in the different positions that will be described as necessary to the operation of the device. These notches should be of such a form as will prevent the accidental displacement of the lever and valve, but that will allow the pawl to be forced out by the turning of the lever. The valve 3 has been described, in the description of Fig. 4 as being in the position that will directly connect the air pump and reservoir on the locomotive with the train-pipe; that is to say, the discharge of air will be positive, as the current does not pass through the other valves in this device. Whenever the valve is in this position the pawl 29 will engage with the notch 24, in the annular projection on the cover B. WVhenever the handle 20 is turned so that the pawl 29 will engage with the notch 25 the port 5, through the valve, will coincide with the port 8 in the part A and all of the other ports will be closed,as shown in Fig. 5. Whenever the valve 3 is in the position just above described the air will pass through the port 8 and through the

valves

13 and 1 1 and the port 18, or not, according to the position of said valves, the position of those valves being governed entirely by the relative pressures in the chamber of the valve 3 and in the train-pipe. It will be seen by reference to Fig. 1 that the lower part of the chamber 12 is connected by the port 16 with the chamber of the valve 3, in which the air tension is that of the locomotive reservoir, and that the pressure in the chambers 12 must therefore be the same as in said reservoir; and that the part of the chamber 12 above the piston 11 is connected with the port 2 by the port 18 which would cause the pressure above the piston in said chamber to be the same as in the train-pipe.

For the purpose of illustrating the automatic operation of the valves 13 and 14 in regulating the supply and exhaust of air we will suppose that the pressure of air below the piston of cylinder 12, and in the chamber of the valve 3, is eighty pounds and that the pressure of air in the train pipe and above the piston in the cylinder 12, has been reduced, for the purpose of applying brakes, to fifty pounds; and, that the pressure exerted by the spring 15 is equal to thirty pounds in the compressed condition in which it is shown and fifteen pounds when it is extended. In these hypothetical pressures given above, and in those to be hereinafter given no account is taken of the unknown but slight and immaterial force required to overcome inertia and friction and to cause the valves to remain securely seated. The piston will be in the position shown only when the pressure below will balance or overcome the pressure in trainpipe and thirty pounds spring pressure, consequently the pressure in the train pipe must be at fifty pounds, or below to produce this static condition which is necessary to the operation of the triple valve in applying the brakes. Whenever the brakes are to be released, and the auxiliary reservoir filled, it is necessary to increase the pressure in the trainpipe by fifteen pounds, making the total pressure in the train-pipe sixty-five pounds as against eighty pounds pressure in the passage 1. This result will occur whenever the port 5 through the valve 3, shall coincide with the port 8, the area of the valves 13 and 14 being exposed to the pressure of the air coming through the port 8, which pressure will overcome the equilibrum above described and cause the piston to descendopening the valve, 14, and thus permitting the air to pass into the train-pipe through that valve and the passage 18. The air will continue in this way to rush into the train-pipe until the pressure on top of this piston shall arrive at sixty-live pounds which, with the pressure of the spring, will depress the piston and open the valve 14 sufficiently to allow the valve 13 (which abuts against the valve 14,) to close and stop the further ingress of air into the train-pipe. It is therefore necessary that spring 15 should exert fifteen pounds pressure when extended by the depression of the piston to the point that will permit the valve 13 to close. The piston and valves will remain in the position just described as long as the spring is assisted by sixty-five pounds pressure, above the piston, to balance the eighty pounds below but should a leakage occur in the pipes, or should the air be exhausted from the trainpipe, in any other way than through the engineers valve, the eighty pounds pressure be low will overcome the pressure of the extended spring and the diminished air pressure above and push the piston up, thus opening the valve 13 and admitting more air into the train-pipe until the equilibrium is again established which will, as before, cause the valve 13 to close whenever the pressure in the train-pipe shall again arrive'at sixty-five pounds after which the piston and the valves will again assume the positions in which they were before the leakage occurred. Whenever the pawls on the handle 20 engage the notch 26 the valve 3 will be in the position shown in Fig. 6, that is to say, none of the ports will be open. Consequently air will be neither charged nor discharged.

The next operation described will be the automatic releasing or discharging the air from the train-pipe; the position'of the valve 3, in this operation being shown in Fig. 7. The valve 3 being turned as shown in that figure will cause the pocket port 6 in said valve to cover and connect the

ports

8 and 9; the port 8 connecting, through the valves 13 and 14, with the train pipe, and the port 9 with the open air. This operation takes place when the pressure on the top of the piston 11 is sixty-five pounds against eighty pounds below said piston which'allows the spring 15 to exert an effectual pressure of fifteen pounds in excess of the resistance thereto against the said piston, the tension expansively of said spring being thirty pounds. This will obviously close the valve 13. The opening of a passage from the port 8 to the open air will cause the air-pressure in the top of the cylin- (ler 12, and the train-pipe to raise the valve 13 and to escape through the pocket-port 6 and the port 9 until said air-pressure in the cylinder shall be so reduced that the pressure under the piston will overcome it and thirty pounds spring pressure, when the valve 14 will close by the action of the piston and hold the air pressure, on top of the piston, at fifty pounds. Whenever the valve 3 is in this position to discharge the air automatically, as shown in Fig. 7, the pawl on the handle will engage with the notch 27, Fig. 18.

The last to be described, of the five positions of the valve 3 is shown in Fig. 8, which position of the valve will require the pawl on the handle 20 to be in the notch 28. When the valve 3 is in this position the pocket port 7 will connect the

ports

2 and 10 which will allow the air in the train-pipe to discharge freely and the quantity discharged, and the pressure remainingjmust be governed by the engineer. It is not desirable to use this combination of ports except in a case of emergency when the automatic operation of the valve would be too slow.

Having thus described my invention, what I I claim as new, and desire to secure by Letters Patent, is-

1. In a device of the classspecified, as a means of automatically exhausting air from the train pipe, an oscillating valve having a pocket port 6, and means for operating it, the

ports

8 and 9 through the seat of saidvalve, the puppet valve 14 attached to a piston that is operated by a pressure of air in the direction that will close said puppet valve, an air passage connecting the train-pipe with the said valve 14 and said piston',a passage that connects said valve 14 with said port 8, and a port connecting the pocket port 6 with the passage that will connect the chamber of the valve 3 with the cylinder of the said piston on the side of the piston opposite the valve 14, substantially as described.

2. In a device of the class specified, as a means of automatically increasing the air pressure in the train-pipe a piston having on one side thelocomotive-reservoir pressure and on the other the pressure in the train pipe and a spring-pressure, a puppet valve that will contact with and be forced open by the piston on said reservoir pressure,overcoming the pressure of the train-pipe and the pressure of the said spring, the port 8 and avalve that will open and close communication between said port and the locomotive reservoir, substantially as described.

3. In a device of the class specified, as a means of automatically reducing the pressure in the train pipe,a cylinder and a piston sliding therein, a port 8 communicating between the upper end of said cylinder and a passage leading to the open air, a valve adapted to close said port 8 at its embouchure into said passage,avalve 14 carried on the piston and set in and adapted to close said port 8 on the piston reaching its point of ultimate elevation, a spring 15 acting to move said piston away from said upper end of the cylinder, a passage 16 connecting the lower end of the cylinder with the air supply, and a passage 18 connecting the upper end of the cylinder with the train pipe substantially as and for the purpose specified.

In testimony whereof I hereunto affix my signature in presence of two witnesses.

HERBERT M. LOFTON. Witnesses:

A. J. DIERK, W. H. LoFToN.