US636770A

US636770A - Time-valve for pneumatic railway-signals.

Info

Publication number: US636770A
Application number: US65685797A
Authority: US
Inventors: Frank L Hodgson
Original assignee: PNEUMATIC RAILWAY SIGNAL Co
Current assignee: PNEUMATIC RAILWAY SIGNAL Co
Priority date: 1897-10-29
Filing date: 1897-10-29
Publication date: 1899-11-14
Anticipated expiration: 1916-11-14

Description

- No. 636,770. Patented Nov. l4, I899.

F. L. Douasou. TIME VALVE ron PNEUMATIC RAILWAY SIGNALS.

(Application filed Oct. 29, 1897.)

(No Model.)

Fig. 1.

THE NORRIS PETERS cc, Pno'r o-uma, WAsHmt-ro. n, c,

UNITED STATES PATENT OFFICE.

FRANK L. DODGSON, OF ROCHESTER, NEW YORK, ASSIGNOR, BY MESNE AS- SIGNMENTS, TO THE PNEUMATIC RAILWAY SIGNAL COMPANY, OF WEST VIRGINIA.

Tl ME-VALVE FOR PNEUMATIC RAILWAY-SIGNALS.

SPECIFICATION forming part of Letters Patent No. 636,770, dated November 14, 1899.

Application filed October 29, 1897. SeriaLNo. 656,857. (No model.)

'To all whom it may concern:

Be it known that I, FRANK L. DODGSON, a citizen of the United States, residing at Rochester, Monroe county, New York, have invented an Improved Time-Valve for Pneumatic Railway-Signals, of which the following is a specification, reference being had to the accompanying drawings.

My invention relates to an improved timevalve for pneumatic railway-signals, which improvement is fully described and illustrated in the following specification and the accompanying drawings, the novel features thereof being specified in the claims annexed to the said specification.

' My invention is represented in the accompanying drawing, in which the figure is a sectional elevation of a time-valve embodying my improvement.

The object of this invention is to furnish means by which a valve used in operating a pneumatic railway-signal may be opened and may be left open for a certain length oftime and may be automatically closed at the expiration of such time. As an illustration, supposingit be required to fill the signal-pipe H in the accompanying drawings to a certain definite pressure, this can be done by operating a Valve between the signal-pipe and the main supply-pipe M and leaving said valve open for a definite length of time, that time depen ding upon the length and area of the pipe H. In order to accomplish this result, I employ a cylinder A, having a side'opening J about midway of its length and containing a piston B, that travels up and down in the cylinder and acts when in its lowest position as a weight to close the time-valve I. The piston and the valve are not connected together but the stem of the valve extends into the path of movement of the piston, and when the piston strikes said stem itcloses the valve, and when the piston is lifted from contact with said stem the valve may open. The piston and the cylinder have such relative proportions that the escape-orifice J is uncovered when the piston is at either the top or the bottom of the cylinder; but when the piston is at other positions in its movement in the cylinder the orifice J is covered by the piston, so that the cylinder is cut off from connection with the outer air.

The piston B is adapted to be raised to the position shown in dotted lines in the figure by air under pressure admitted through the operating-pipe O and the valve D. The valve D is an ordinary three-way valve with an ample escape-orifice to the outer air, as usual. The raising of the piston B high enough to lift it from contact with the valve I permits the pressure of the air from the main M through the branch pipe E to raise the valve I, so as to open the port F, through which the air passes into the pipe H. As the piston rises the air in the cylinder above it passes out freely through the opening J, thus permitting a rapid upward movement of the piston at first and a quick release of the valve I. The piston in its further upward movement soon closes the escape-orifice J, andafter said orifice is thus closed the air passes out freely through a back-pressure checkvalve G at the upper part of the cylinder. After sufficient air has been admitted, as above described, by the proper turning of the valve D to raise the piston to its highest position the valve is turned so as to close it, or, if desired, the valve may be kept open, and the piston may thus be held in the upper part of the cylinder and away from the valve I. When the piston has arrived at the upperend of its travel, it uncovers the escape-orifice J in the side of the cylinder and allows the compressed air below the piston to escape, which permits the piston to drop quickly until the orifice J is again closed. It must be understood that the opening of the Valve D to admit the air to the cylinder is ordinarily but momentary. After the piston has dropped partly back, as just described, the valve D is turned so as to connect with the outer air through its escape-orifice above mentioned, and thereupon the piston will descend and the air in the cylinder underneath the piston passes out through the pipe 0 and valve D. The time occupied by the descent of the piston B is regulated .by the restricted admission of air into the upper part of the cylinder through the valve K, which may be set so that the piston may descend at any desired rate of speed. The cock or valve K may be of any usual or preferred type and maybe arranged to be set with any desired amount of opening through it for the said restricted admission of air. When the piston B arrives at the end of its downward movement, the orifice J is again uncovered, permitting air to pass freely into the upper end of the cylinder, and thus permitting a quick downward movement of the piston, so that it closes the valve I with some force by contact with its stem L, and the weight of'the piston holds the valve I closed against pressure of air from the main E. The stem L projects upward from the valve I through a collar N, inserted in the upper end of the tube or valve casing O in the lower cylinder-head P. At each end of its travel the valve I seats against a packing ab within the valve-casing. The port F opens laterally through the valve-casing O and thence extends downward through the cylinder-head, connecting with the pipe II.

The valve D may be arranged to be operated in any suitable way-as, for instance, by hand or by the passage of a train. As shown in the drawings, the device is operated by hand, although the valve D may be set at any desired distance from the cylinder A.

It will be noticed that the upward movement of the piston, so far as is necessary to allow the valve I to be lifted, is a free movement, and that the movement of the piston through that part of its stroke that closes the valve I is likewise a free movement, and that the device produces quick action of the signal-valve I, both for opening and for closing the air-inlet from the main M to the signalpipe H, permitting at the same time a definite interval of time to elapse for the closing of the valve after the operating-valve D is set to its normal position. The employment of the three-way valve for operating this device and the normal setting of said valve in the position described above renders accidental operation of the piston, and consequently of the signal, practically impossible.

I claim 1. In a railway-signal time-valve mechanism, a valve controlling the signal-pipe, a gravity device normally holding the valve on its seat to close the inlet to said pipe, means for lifting said gravity device from said valve, and automatic means for controlling the rapidity of return of said gravity device to restore said valve to its seat, substantially as described.

2. The combination, with the upright cylinder A, of the piston 13, the escape-valve G, the regulating inlet-valve K, said valve being connected with the highest part of the cylin der, the time-valve I having a stem extending into the path of movement of the piston, a pipe connecting with the cylinder for operating the piston, and a signal-pipe controlled by the time-valve, substan tially as described.

3. In a time-valve for pneumatic railway signals, the combination of a cylinder, a regulatable inlet-valve connecting with one end of said cylinder and an escape device, a piston in said cylinder, a pipe connecting with said cylinder for operating the piston, a threeway valve controlling said pipe, a main supply-pipe, a signal-pipe, a valve disconnected from said piston and held closed by the weight thereof, and adapted to be raised to open communication between the main supplypipe and the signal-pipe upon the raising of the piston, substantially as described.

4. The combination, in a time-valve for pneumatic railway-signals, of the cylinder A, the piston B, a pipe connecting with said cylinder for operating the piston, the lower cylinder-head having the valve-casing O, the time-valve in said casing disconnected from said piston and having the stem L guided in said casing and extending within the cylinder, and suitable connecting-pi pin g, substantially as described.

5. The combination with the upright cylinder A, of the piston B, escape-valve G, regulating-valve K, time-valve I, inlet-pipe O having valve D, the escape-orifice J and suitable connecting-piping,substantially as described.

FRANK L. DODGSON.

Witnesses:

GERTRUDE C. BLACKALL, S. P. MOORE.