US2028605A - Signal valve device - Google Patents

Description

5631.21, 1936. HEWlTT 2,028,605

SIGNAL VALVE DEVICE- Filed Jan. 13, 1933 w i p l 4 INVENTOR 4 s I ELLIS E.HEWITT i ATTORNEY Patented Jan. 21, 1936 UNITED d'l'ATEE zszasts fiATEN'i OFFHQE SIGNAL vAL'vn DEVICE Application January 13, 1933, Serial No. 651,487

22 Claims.

This invention relates to signal valve devices and more particularly to a signal valve device adapted to be controlled by variations in fluid pressure.

5 The principal object of my invention is to provide an improved pneumatically controlled signal valve device which is light in weight, simple in construction, cheap to manufacture and very sensitive to variations in fluid pressures, and which, at the same time, is stable against accidental operation by unintentional fluctuations in fluid pressures.

The fluid pressure signal system employed on railway trains usually comprises a signal whistle and a signal valve device located on the locomotive or head vehicle of the train, a signal pipe and a vent valve device on one or more cars of the train adapted to be operated by a traimnan to vent fluid under pressure from the 20 signal pipe to effect the operation of the signal valve device to supply fluid under "pressure to the signal whistle to cause the whistle to sound a signal. The operating characteristics of the type of signal valve device now in common use 25 are such that if the signal vent valve device is maintained in venting position for a given period of time on either a short or a long train, the duration of the signal blast from the signal whistle will vary according to the length of the train, 30 that is to say that the signal blast on a long train will be of shorter duration than on a short train. The trainman of course tries to produce signal blasts of uniform duration and, in attemping to produce such signals, he must esti- 35 mate the length of the train and approximate, as nearly as possible, the period of time the vent valve device is to be maintained in venting position. It will thus be seen that, since the trainman must use his own judgment as to the length & of the train and as to the period of time the vent valve device is to be maintained in venting position, signals of uniform duration cannot be dependably efiected.

Since it is very diflicult to effect signals of substantially uniform duration with the signal valve devices now employed, only one code of signals can be safely used, which code consists of one or more signal blasts regardless of the length of each blast.

Another object of my invention is to provide a pneumatically controlled signal valve device which, when employed in a railway train signal system, will function, regardless of the length of the train, to cause the engineers signalwhistle to sound a signal of substantially uniform duration upon the trainman maintaining the vent valve device in venting position for a predetermined period of time, thus eliminating the aforementioned difficulties and making it possible to safely use a code of signals consisting of signal blasts of varying duration which results in the saving of signal pipe air and makes it possible for the trainman to transmit intelligence to the engineer in a shorter period of time than is now required by the use of the old code.

Other objects and advantages will appear in the following more detailed description of the invention.

In the accompanying drawing, Fig. 1 is a cross sectional view of a. signal device embodying my invention; Fig. 2 is an enlarged detail cross sectional view of a portion of the signal device showing the particular construction of one 0! the valves of the device; Fig. 3 is a sectional view taken on the line 3-3 of Fig. 1; Fig. 4 is a side elevational view of one of the end portions of the device; and Fig. 5 is a diagrammatic view of a train signal system embodying my invention, the equipment for the locomotive and two cars being shown.

According to the drawing, the signal valve device may comprise an annular cast metal casing section B and alsopcmprises sheet metal casing sections 2 and 3 which are clamped to the casing section I by bolts 4 which pass through registering openings in the section I, an annular flange 5 of the section 2 and an inturned flange 6 oi the section 3, the inner end of each bolt having screw-threaded connection with a lug l which is preferably welded to the flange 5, and the head 35 of the bolt engaging the outer surface of the flange 5 of thesection 2.

In the present embodiment of the invention, supporting brackets 8 are welded to the exterior of the casing section 2, which brackets are adapted to be secured in any desired manner to a suitable supporting structure, (not shown). Also welded to the exterior of the casing section 2 is a lug 9 having a passage Ill formed therein which is open at one end to a passage ll in the casing section and open at the other end to a pipe H2 which is in communication, in the usual manner, with a train signal pipe 50 which is continuous throughout the length of the train.

The casing section I is provided with integral spaced arms l3, l4 and I5 which merge together at the center of the section, the arm it: having a passage it formed therein which is open at one end to a pipe ll leading to a signal whistle it, said passage being open at the other A5 end to a recess I9 formed in the central portion of the casing section. Secured to the central portion of the casing section, within the recess I9, is a choke plug 29 having a restricting passage 2I which is open at all times to the chamber I9 and also having a seat rib 22 on which a valve 23 hereinafter described, is adapted to seat.

Clamped between the casing sections I and 2 is a flexible diaphragm 24 and clamped between the casing sections I and 3 is a flexible diaphragm 25, said diaphragms, togethen with the casing sections defining chambers 26, 21 and 28, the chamber 26 being in constant communication with the train signal pipe by way of passage II in the casing section 2, passage I in the lug 9 and pipe I2.

Between the flexible diaphragms' there is arranged a follower member comprising followers 29 and 39 which are rigidly secured together in spaced relation to each other by spaced struts 3I', the follower 29. engaging one side of the flexible diaphragm 24 and the follower 39 engaging one side of the flexible diaphragm 25. Contained in the chamber 26 and engaging the other side. of the diaphragm 24 is a follower 32, and contained in the chamber 28 and engaging the other side of the diaphragm is a follower 33, said followers and follower member being clamped together and to the flexible diaphragms by means of machine bolts 34 having screw-threaded connection with the fo-l lower struts 3I. This diaphragm and follower assembly constitutes a movable abutment for controlling the operation of certain valves as hereinafter described.

The follower 32 is provided with a central recess 35 containing the valve 23 and also containing a spring 5I which tends to maintain the valve seated on the seat rib 22'. This recess is in constant communication with the chamber 26 by way of a small port 36 in the follower.

The follower 29 is provided with an opening 31 for the accommodation of the valve seat portion of the choke plug 29. This opening is of less diameter than that of the valve 23, so that the follower 29 operatively engages one side of the valve. The valve 23, beyond its seating portion, is provided with perforations 38 through which the recess 35 is in constant communication with the chamber 21 by way of the opening 31 in the follower 29.

The follower 33 is provided with a central bore 39 containing a valve 40 having a stem M which is slidably guided within the central bore 42 of a follower stem 43 having screw-threaded connection, at one end, with the follower 33 within the bore 39, said valve being subject to the pressure of a spring 44 interposed between and engaging the valve 49 and stem 43. The follower stem 43, at its other end, is slidably guided in a guide member 45 which is welded or otherwise secured to the casing section 3.

The valve 49 is provided with an extension 46 which is preferably round in cross section and tapers from its greatest diameter adjacent the valve seating surface to its lesser diameter at its end. This projection extends through a port 41 in the follower which is normally closed by the valve.

The chamber 28 is constantly open to the bore 39 in the follower 33 by way of a port 48 and is also constantly open to the chamber 21 through a port 49 of small diameter in the follower 33'.

Interposed between and engaging the casing section 2 and the follower 32 is acoil spring 59 which is adapted to function to prevent the signal valve device from operating to effect a signal under unintentional fluctuations in signal pipe pressure caused by leakage of fluid from the signal pipe or otherwise.

When the signal pipe 69 is charged with fluid under pressure in the usual manner, fluid from this pipe flows through the pipe I2, passage II! in the lug 9 and passage I I in the casing section 2 to the chamber 26. From the chamber 26, fluid flows to the chamber 21 by way of port 36 in the follower 32,.recess 35, perforations 38 in the valve 23 and opening 3'! in the follower 29. Fluid under pressure flows from the chamber 21 through the port 49 to the chamber 28. Thus the chambers 26, 21 and 28 are charged with fluid to the pressure normally carried in the signal pipe. It will here be noted that in charging these chambers, the diaphragms may have a tendency to flex inwardly due to the chambers 26 and 21 being charged more rapidly than the chamber 28 can be charged through the small port 49, but before the diaphragms can be unduly flexed in this direction; they are brought to a stop by the follower 29 contacting with stops 52 carried by the arms I3, I4 and I5 of thecasing section I.

From an inspection of Fig. 1 of the drawing it will be seen that there is sufficient clearance space provided between the valve 23and the follower 32, that, when the diaphragms flex inwardly, they will not act to materially increase the seating pressure of the valve on the seat 22, thus y effectively preventing the valve from being cut or unduly worn by the seat 22. The inward flexing of the diaphragms does cause a slight additional compression of the spring 5|, but the increase in. the pressure of the valve on its seat, due to such compression, is so slight as to be negligible.

In order to signal the engineer, a car discharge valve 91 of the usual well known construction, is operated by a trainman tovent fluid from the signal pipe. A reduction in fluid pressure is thus effected in chambers 26 and 21 in the signal valve device and, since the pressure of fluid in these chambers is reduced at a faster rate than fluid can flow from the chamber 28 through the small port 49 in the follower 33, the higher fluid pressure in the chamber 28 will act to deflect the diaphragms 24 and 25 outwardly in unison.

The follower 29, as it is moved outwardly by the diaphragms, raises the valve 23 from the seat 22, permitting fluid under pressure to flow from the chambers 26- and 2'! through the passage 2| in the choke plug 29, passage l6, pipe I1 and Whistle I8 to the atmosphere. The diaphragms continue to move outwardly and following the unseating of the valve 23, the tapered extension 46 of the valve 49 is moved into abutting engagement with the arm I5 of the casing section I, so that the continued movement of the diaphragms causes the follower plate 33 to move relative to the valve 49, and the seat for such valve is moved out of seating engagement with the valve. In addition to the flow of fluid through the small port 49, fluid now flows from the chamber 28 to the atmosphere by way of passage 48 in the follower 33, bore 39, past the open valve 49 and its tapered extension 46, chamber 21, past the unseated valve 23, passages 2I and I6, pipe I? and whistle I8. Fluid continues to flow from the chamber 26 and connected signal pipe through the whistle l8. It will here be understood that the rate of flow of fluid from the chamber 28 to the whistle when the valve 46 is open will exceed that of the flow of fluid from the chamber 26 by way of the passage 36.

Now when the pressure of fluid in chamber 28 has been reduced by the flow of fluid to the whistle to substantially the pressure of fluid in chamber 26 or slightly below the pressure of fluid in chamber 26, the diaphragms and parts associated therewith, will be flexed inwardly to their normal positions as shown in Fig. 1, in which the valve 23 is seated, closing off the flow of fluid to the whistle i8 and in which the follower 33 seats on the valve 40, closing communication from the chamber 28 to the chamber 21 by way of the passage 48.

The spring 59 which is primarily for the purpose of stabilizing the valve mechanism against accidental operation due to unintentional fluctuations in signal pipe pressure, also functions to assist in shifting the valve mechanism to its normal position.

Since the volume of the signal pipe varies with the length of the train, the rate and amount of reduction in the pressure of fluid in the chamber 26 of the signal valve device on a short train will be greater than on a long train where the vent valve device 61 is maintained in venting position for a predetermined time.

With the signal valve devices now in common use, if the vent valve device were maintained in venting position for the same period of time on a short or long train, the resulting signal blast would vary according to the length of the train, in other words, the longer the train is the shorter will be the signal blast.

According to one feature of my invention, the tapered extension 46 of the valve 40 so controls the rate of flow of fluid from the chamber 28 to the whistle 18 according to the reduction in signal pipe pressure, that when the car vent valve is operated in the usual manner, as above described, the period of time over which the whistle sounds will be uniform regardless of the length of the train, as will readily be understood from the following description.

On a short train, when the car vent valve is opened and maintained open for a predetermined period of time, the rate and amount of reduction is the pressure of fluid in the chamber 25 will be such that the diaphragms 24 and 25 will be caused to quickly flex outwardly until such flexing is stopped by the follower 30 engaging stops 53 carried by the arms l3, land 15 of the casing section I. In this position, the maximum rate of flow of fluid past the tapered extension 46 of the open valve 40 is permitted, causing a fairly rapid reduction in the pressure of fluid in the chamber 28 to create a suificient pressure difierential on the diaphragms to cause them to operate to effect the seating of the valve 23 and the consequent closing ofi of the flow of fluid to the whistle [8.

On a long train, when the car vent valve is maintained open for the same period of time that it is maintained open on a short train, due to the greater length and volume of the signal pipe, the rate of reduction and consequently the amount of reduc ion in the pressure of fluid in the diaphragm chamber 26 will be less than on a short train. As a result of this, the diaphragms will not flex outwardly to the same extent that they do on a short train, consequently the tapered projection 46 of the valve 40 will retard the flow of fluid from the chamber 28 to a greater extent than when the diaphragms are flexed to their extreme outer position. By thus retarding the flow of fluid from the chamber 28, the valve 23 is maintained open for a longer period of the operation of the signal valve device so as to produce a signal blast of uniform length.

From the foregoing description it will be seen that the signal valve device will function to cause the signal whistle I8 to sound a signal blast of substantially uniform duration regardless of the length of a train when the signal vent valve device is maintained open for a predetermined period of time.

While one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope to that embodiment or otherwise than by the terms or the appended claims.

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

1. .In a fluid pressure signal system for a train, the combination with a train signal pipe charged with fluid under pressure, of a pneumatically operated signal indicating device, a valve device operative to vent fluid under pressure from the signal pipe, and means responsive to a reduction in signal pipe pressure, upon the vent valve device being maintained in venting position for a predetermined period of time, to supply fluid under pressure to the signal indicating device to efiect the operation of the signal indicating device to indicate a signal for a predetermined uniform period of time regardless of variations in the rate and amount of reduction in signal pipe pressure.

2. In a fluid pressure signal system for a train, the combination with a train signal pipe charged with fluid under pressure, of a pneumatically operated signal indicating device, a valve device operative to vent fluid under pressure from the signal pipe, and valve means operative in trains of diflerent lengths to supply fluid under pressure to said signal indicating device fora uniform period of time when the vent valve device is maintained in venting position for a predetermined period of time.

3. In a fluid pressure signal system for a train, the combination with a train signal pipe charged with fluid under pressure, of a pneumatically operated signal indicating device, a valve device operative to vent fluid under pressure from the signal pipe, and valve means operative upon a reduction in signal pipe pressure for supplying fluid under pressure from said chamber to the signal indicating device, and means for automatically regulating the rate of flow of fluid from said chamber to the signal indicating'device according to the reduction in signal pipe pressure.

5. In a fluid pressure signal system, the combination with a signal pipe, of a fluid pressure operated signal indicating device, a signal valve device subject to the opposing pressures of the signal pipe and a chamber and operated upon a reduction in signal pipe pressure for supplying fluid under pressure to the signal indicating device, and means included in the signal valve device for varying the rate of flow of fluid to the signal indicating device according to the reduction in signal pipe pressure.

6. In a fluid pressure signal system, the combination with a signal pipe, of a fluid pressure operated signal indicating device, a signal valve device subject to the opposing pressures of the signal pipe and a chamber and operated upon a reduction in signal pipe pressure for supplying fluid under pressure from said pipe and chamber to the signal indicating device, and means for varying the rate of flow of fluid from the chamber to the signal indicating device according to the reduction in signal pipe pressure.

' 7. In a fluid pressure signal system, the combination with a signal pipe, of a fluid pressure operated signal indicating device, a signal valve device subject to the opposing pressures of the signal pipe and a chamber and operated upon a reduction in signal pipe pressure for supplying fluid under pressure from said pipe and chamber to the signal indicating device, and means for varying the rate of flow of fluid from said chamber according to the reduction in signal pipe pressure.

8. In a fluid pressure signal system, the combination with a signal pipe, of a fluid pressure operated signal indicating device, a signal valve device subject to the opposing pressures of the signal pipe and a chamber and operated upon a reduction in signal pipe pressure for supplying fluid under pressure from said pipe and chamber to the signal indicating device, and operated upon a reduction in the pressure in said chamber by the flow of fluid therefrom to the signal indicating device to close off the flow of fluid to the signal indicating device, means for varying the rate of flow of fluid from the chamber according to the reduction in signal pipe pressure, and means restricting the rate of flow of fluid from the signal pipe to the signal indicating device.

9. In a fluid pressure signal system, the combination with a signal pipe, of a fluid pressure operated signal indicating device, a signal valve device subject to the opposing pressures of the signal pipe and a chamber and operated upon a reduction in signal pipe pressure for supplying fluid under pressure from said pipe and chamber to the signal indicating device and operated upon a reduction in the pressure in said chamber by the flow of fluid therefrom to the signal indicating device to close ofl the flow of fluid to the signal indicating device, means for varying the rate of flow of fluid from the chamber according to the reduction in signal pipe pressure, and means restricting the flow of fluid from the signal pipe to the signal indicating device to a rate slower than the slowest rate of flow of fluid from the chamber to the signal indicating device.

10. In a fluid pressure signal system, the combination with a signal pipe and a signal indicating device, of a signal valve device comprising a valve operative to control a communication through which fluid under pressure is adapted to be supplied to the signal indicating device, a movable abutment subject to the opposing pressures of the signal pipe and a normally charged chamber for operating said valve, valve means operated by said abutment upon a reduction in signal pipe pressure for venting fluid under pressure from said chamber, and means associated with said valve means and cooperating with said abutment for varying the rate of flow of fluid from said chamber.

11. In a fluid pressure signal system, the combination with a signal pipe and a signal indicating device, of a signal valve device comprising a valve operative to control a communication through which fluid under pressure is adapted to be supplied to the signal indicating device, a movable abutment subject to the opposing pressures of the signal pipe and a normally charged chamber for operating said valve, and valve means operated by said abutment upon a reduction in pressure in the signal pipe for venting fluid from said chamber at a rate according to the reduction in pressure in the signal pipe.

12. In a fluid pressure signal system, the combination with a signal pipe and a signal indicating device, of a signal valve device comprising a valve operative to control a communication through which fluid under pressure is adapted to be supplied to the signal indicating device, a movable abutment subject to the opposing pressures of the signal pipe and a normally charged chamber for operating said valve, and valve means carried by said abutment and operative upon a reduction in signal pipe pressure for venting fluid from said chamber to the signal indicating device at a rate according to the reduction in signal pipe pressure.

13. In a fluid pressure signal system, the combination with a train signal pipe charged with fluid under pressure and a fluid pressure operative signal indicating device, of a signal valve device comprising a plurality of signal controlling valve mechanisms, a movable abutment subject to the opposing pressures of the signal pipe and a normally charged chamber for controlling the operation of said valve mechanisms and operated upon a reduction in signal pipe pressure for operating said valve mechanisms to supply fluid under pressure from the signal pipe and chamber to the signal indicating device, and means included in one of said valve mechanisms for regulating the rate of flow of fluid from said chamber to the signal indicating device according to the reduction in signal pipe pressure.

14. In a fluid pressure signal system, the combination with a train signal pipe charged with fluid under pressure and a fluid pressure operative signal indicating device, of a signal valve device comprising a plurality of signal controlling valve mechanisms, a movable abutment subject to the opposing pressures of the signal pipe and a normally charged chamber for controlling theoperation or" said valve mechanisms and operated upon a reduction in signal pipe pressure for operating said valve mechanisms to supply fluid under pressure from the signal pipe and. chamber to the signal indicating device, means included in one of said valve mechanisms for varying the rate of flow of fluid from said chamber to the signal indicating device according to the reduction in signal pipe pressure, and means for restricting the flow of fluid from the signal pipe to the signal indicating device.

15. In a fluid pressure signal system, the combination with a train signal pipe charged with fluid under pressure and a fluid pressure operative signal indicating device, of a signal valve device comprising a plurality of signal controlling valve mechanisms, a movable abutment subject to the opposing pressures of the signal pipe and a normally charged chamber for controlling the operation of said valve mechanisms and operated upon a reduction in signal pipe pressure for operating said valve mechanisms to supply fluid under pressure from the signal pipe and chamber to the signal indicating device, means included in one of said valve mechanisms for varying the rate of flow of fluid from said chamher to the signal indicating device according to the reduction in signal pipe pressure, and a restricted port in said abutment for governing the flow oi fluid from said signal pipe to the signal indicating device.

16. In a fluid pressure signal system, the combination with a train signal pipe charged with fluid under pressure and a fluid pressure operative signal indicating device, of a signal valve de-- vice comprising a plurality of signal controlling valve mechanisms, a movable abutment subject to the opposing pressures of the signal pipe and a normally charged chamber for controlling the operation of said valve mechanisms and oprated upon a reduction in signal pipe pressure for operating said valve mechanisms to supply fluid under pressure from the signal pipe and chamber to the signal indicating device, means included in one of said valve mechanisms for varying the rate of flow of fluid from said chamher to the signal indicating device according to the reduction in signal pipe pressure, and means for restricting the flow of fluid from the signal pipe to the signal indicating device to a slowerv rate than the rate at which fluid under pressure is supplied from said chamber to the signal indicating device.

17. A signal valve device comprising a casing having end sections and an intermediate section having a passage through which fluid under pressure is adapted to be supplied to: a signal indicating device, means securing said casing sections together, a flexible diaphragm clamped between each end casing section and the intermediate casing section, means clamping said diaphragms together to operate in unison, and valve means carried by the means clamping said diaphragms together adapted to cooperate with the intermediate casing section to control the flow oi fluid to said passage.

18. A signal valve device comprising a casing having end sections and an intermediate section, means clamping said casing sections together, a flexible diaphragm clamped between each end casing section and the intermediate casing section, a member disposed between the diaphragms and carried by the intermediate casing section, said member having a passage through which fluid under pressure is adapted to be supplied to a signal indicating device, and means carried by said diaphragms adapted to cooperate with said member for controlling the supply of fluid under pressure to said passage.

19. A signal valve device comprising a casing having a passage through which fluid under pressure is adapted to flow to operate a signal indicating device, a flexible diaphragm mounted in said casing, a diaphragm plate at one side of said diaphragm having a recess formed therein, a valve seat carried by a portion of the casing, a valve mounted in said recess and normally engaging said valve seat to close said passage, a diaphragm plate at the other side of the diaphragm operatively engaging one side of said valve, means clamping said diaphragm plates to the diaphragm, the second mentioned diaphragm plate being adapted to move said valve to its open position upon the flexing of the diaphragm in one direction, and a spring interposed between and engaging the first mentioned diaphragm plate and valve for exerting a seating pressure on the valve when the diaphragm is flexed inwardly.

20. A signal valve device comprising a casing having a passage through which fluid under pressure is adapted to flow to operate a signal indicating device, a flexible diaphragm mounted in said casing, a diaphragm plate at one side of said diaphragm having a recess formed therein, a valve seat carried by the casing, a valve mounted in said recess and normally engaging said valve seat to close said passage, a diaphragm plate at the other side of the diaphragm operatively engaging one side of said valve, means clamping said diaphragm plates to the diaphragm, said diaphragm and diaphragm plates being movable inwardly relative to said valve and the second mentioned diaphragm plate being adapted to move said valve to its open chamber normally charged with fluid under pressure and responsive to a reduction in signal pipe pressure for effecting the operation of said signal indicating device and for venting fluid under pressure from said chamber, and means for varying the rate at which fluid is vented from said chamber according to the rate at which the signal pipe pressure is reduced.

22. In a fluid pressure signal system, the combination with a signal pipe charged with fluid under pressure, of a valve device responsive to a reduction in signal pipe pressure for effecting the operation of said signal indicating device, and means for conditioning said valve device to effect the operation of said signal indicating device for a substantially constant period of time, regardless of the rate and amount of reduction in signal pipe pressure.

ELLIS E. HEWITT.

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