US1352853A - Automatic starting and equalizing pressure-valve for compound engines - Google Patents

Description

l 1. B..VERN0N. AUTOMATIC STARTING AND 'EQUALIZING PRESSURE VALVE FOR- COMPOUND' ENGINES.

APPLlcATl'oN man A uc.2'1.'191z.

' Patented 86151;. I'14,I 1926.

GMM/Mugs.

l y 1. B'. VERNON. -AUTEIMIITIC STARTING AN D EQUALIZING PRESSURE VALVE FOH COMPOUND ENGINES.

' APPLICATION FILED AUG.2I, I9I7.

PatentedSept. 14, 1920.

2 SHEETS-SHEET 2.

31a/Denton vUNITE STATES P TsNT orifice.l

JAMES B. VERNON, 0FV PRINCETON, WEST -VIRGINIA. t

Specification of Letters Patent. Pat-entedsepf. 14, lgga Application led August 21, 1917. Serial Nb. 187,459.

To all whom t may concern 4 Be it known that I, JAMES B; VERNON, a citizen of the United States, residing at Princeton, in the county of Mercer and State of IVest Virginia, have invented certain new and useful Improvements in Automatic Starting and Equalizing Pressure-Valves for Compound Engines, of whichv the following is a. specification.

My invention relates to new and useful improvements in valves and has as its primary object the provision of an automatic starting and equalizing pressure valve for compound .engines of locomotives.

-It has long been recognized that in the employment of compound engines, 'such as those of the Mallet type von locomotives,l

some means for admitting live steam to the low pressure engine or cylinder is desirable inasmuch as a train when starting requires the Vgreatest possible engine power. Ob-

' viously, when starting the locomotive it is necessary with the previously employed arrangements that the high pressure engine or cylinder operate through several revolutions of the drivers before any appreciable amount of steam is supplied to the low pressure engine, this being due to the fact that there are such rapid condensationsot `the steam that the exhaust steam from the high pressure engine is of little benefit until the l'ocomotive is well under way.

Because ot this failure to supply steam to the low pressure cylinder, undesirable slipping of the high pressure engine is caused as the low pressure engine has no pressure to build up against the high pressure engine and when the high pressure engine slips the low pressure engine will also slip. Furthermore, when the low pressure -engine slips, on account of difference in volume of the cylinders of the two engines, the steam is exhausted faster than the high pressure engine can supply it, which, consequently, reduces back pressure on the high aressure enOine and makes it liable to slin-k pino'. v

@one of the chier" objects of my present invention isv the provision oIrl a valve which will overcome these defects by providing live steam to the low enginey at the time the locomotive is being Started and which will continue to supply live steam to such engine until the exhaust steam from the high pres-y,

sure engine passing to the low pressure enproper ratio still further' object which I have in View is theprovision of means by which thel valve may be opened at any desired time by the engineer. Y t In addition to accomplishing these objects, `I also provide a structure which is simple, economical to manufacture and install and durable and eiiicient in use.

In the drawings:

Figure 1 isl a central verticall-secti'ona view taken through the valve,

Fig. 2 is a transverse sectional view taken on the line 2 2 of Fig. 1 looking in the directon of the arrows, Y

Fig. 3 is a fragmentary perspectiveview illustrating the application of the valve.

AFig- 4 is a view illustrating a locomotive of the compound type to which the inven tion is applied. Y

Corresponding and like parts arereferred to in the following description andV indicated in all the views of the drawings by the saine reference characters.

In order toinsure a clear and accurate understanding of my invention and its operation, I will rst describe the construction of the valve, then its application in connection with the engine and then its operation.

The main body or casing of the valve indicated in general by the reference letter A includes an intermediate section 10 and terminal sections 11v and 12. The intermediate section is formed in one side with an opening surrounded by an internally threaded nipple 13 and at its top is reduced and ex; ternally threaded, asl shown at 14, ior engagement with the lower end of the terminal section 11. rlhis reducing of the top oit' the Section-10 provides a stop shoulder 15 which .insures a close joint between the two sec of the passage through the nipple 13 which-k is the outlet passage of the Vvalve and serves spider 21 ormedacross the terminal section 11. A helical spring 22 surrounds the valve stem bea-ring at one end against the spider.

16V and at its opposite end against the lower face of the valve 18 which is formed with a central boss 23 to centralize the spring 22. This' spring 22, of course, acts yto maintain the valve in open position and the extent to which the valve may open is limited by the stopshoulder 24. at the junctur'e of the valve stem and its reduced terminal 20. The upper end or the terminal section 11 is formed with an 'inlet opening surrounded by an internally threaded nipple 25.

The lower end of Athe intermediate section is internally threaded to receive the threaded upper end 26 of the lower terminal section 12 which is threaded for engagement with the section 10 and which, adjacent its threaded portion, is provided with a stopA flange 27 to insure a close joint between the sections. rIhe outer or peripheral face of this flangeis formedwith flattened faces to receive a wrench or other suitable tool in order that it may be readily applied. The lower end of the terminal section 12 is internally threaded to receive a plug cap 28 and adjacent the lower end, the section 12 is formed with a lateral internally threaded opening 2). lnterioriy, the casing section 12 is-iermed withv an upper axial cylindrical chamber 30 opening into a lower axial lcylindrical chamber v31, of somewhat greater diameter.

Mounted within these chambers is a plunger 32 which, intermediate `the length of the chamber 31, is reduced to receive a pluralitv of washers each or" which has its upper face channeled tovprovide an. annular external seat fora packing ring 34 of brass or other suitable material. Engaging against the lowermost of these washers is the sleeve portion 35 of a piston, indicated as a whole by the numeral 36. The upper end ofthis sleeve portion is cut away to provide a seat for one of the packing rings 34. The under face of the upper portion-of` the piston, which is formed integrally with this sleeve, is channeled to provide a seat for a brass packing ring 37. A washer 38, forming the intermediate section of the piston, engages the packing ring and a terminal section 39 of the piston engages this washerl and is channeled to receive another packing ring 40. The lower end of the plunger is threaded'to receive a nut 41 which clamps piston 42 formed by the washers 33 and tion to the fact that the opening or port 43 surrounded by the nipple 25 constitutes the live steam opening of the valve and the opening 44 surrounded by the nipple 13constitutes the steam outlet of the valve, the opening 29 constituting means for admitting either steam or air under pressure to operate the compound pistons 36 and 42 to cause opening of the valve 18 when desired, independent of the normal automatic operation of the valve.

In Figs. 3 and 4 I have illustrated the manner of applying my improved valve to a locomotive engine of the compound type, in which 45 indicates the high pressure engine, 46 the low pressure engine and 47 a conduit for supplying live steam to the high pressure cylinder. Suitable pipe iittings 48 connect at one end to the nipple 25 and at the other end communicate with the conduit 47, while pipe fittings 50 establish communication between the port 44 of the casing and the exhaust passage leading from the high pressure cylinder to the low pressure cylinder. A pipe 49 is led from the port 29 to' any suitable source of compressed iuid, such as the main reservoir of the air brake system or the steam boiler, a manually controlled operating valve 50 being interposed in this pipe within the locomotive cab and normally kept closed.

In describing the operation of my improved valve, 1 will assume that the engine is stationary and that as a result there is no steam in the cylinders or in the conduit 47. Under these conditions, fluid pressure will'be equal against opposite sides of the valve 18 and the spring 22 will hold the valve open. Y When by the usual gradual opening of the throttle steam is admitted to the conduit 47 and so to the high pressure cylinder 45 to start the engine, a portion of this live steam will pass through the pipe 48 to the valve casing, escaping through the port 44 to the receiver pipe or passage leading from the high pressure to the low pressure cylinder. As the engine starts under steam pressure from the high pressure cylinder, the low pressure cylinder will take steam with the result that the pressure in the valve casing below the valve 18 will be suddenly reduced to such an extent that the unbalanced pressure of live steam above the valve will close it against the action of the spring 22. Thether or not the valve then remains closed will depend upon running conditions.

.At this point it should be noted, that due rio tween the high and low pressure cylinders,

which is the relative steam pressure at oppo site sides of the valve 18, will bear a constant ratio to each other, that of the exhaust passage being a predetermined fraction of that in the conduit 47. F or instance,

to increase the steam pressure in the exl haust passage a pound, it may be necessary to increase the live steam pressure in the conduit 47 four pounds. It will therefore be obvious that in starting the engine, steam pressure will be brought up in the live steam passage at a much fasterrate than in the exhaust conduit.

Under running conditions the pressure'in the high pressure cylinder and the pressure in the low pressure cylinder will bear a certain denite ratio to each other and if the pressure in the high pressure cylinder is from any cause reduced, the pressure in the low pressure cylinder will, of course, be reduced in accordance with such ratio. The spring 22 is capable of exerting a predetermined constant degree of pressure against the valve tending to open the same, and this predetermined degree of pressure to be exerted by the spring is such thatwhen the pressure against the upper side of the valve, or in other words, the pressure in the high pressure cylinder is reduced to a predetermined degree, the pressure, in ratio, in the low pressure cylinder plus the pressure exerted by the spring will more than balance the said pressure against the upper side of the valve and the valve will open, For example, if it is desired that live steam be admitted to the lowpressure cylinder upon reduction of pressure inthe high pressure cylinder to 100 pounds, and assuming that with such a degree of pressure in the high pressure cylinder there is a pressure of 20 pounds in the low pressure cylinder, a spring will be provided which will exert a pressure orn approximately 85 pounds against the valve tending to open the valve; so that, when under running conditions the pressure in the high pressure cylinder falls to 100 pounds, the combined pressure of the spring and the back pressure of the steam in the low pressure cylinder`will result in automatic opening of the valve. Of course, so long as the pressure in the high pressure cylinder is above the predetermined minimum the valve will remain closed unless it is opened through admission of fluid under pressure beneath the plunger 36.

The strength of the spring 22 is to be determined by the high cylinder pressure at which the valve 18 is to open. Customarily,

the pressure in the two cylinders is at a ratio of 4 to 1, sol that when the high cylinders are werking under 200 pounds pressure the low cylinders and receiver pipe will be carrying 50- pounds pressure. If the high cylinder pressureshould fall to 95 pounds, the low cylinder pressure would drop to approxi-l mately 25 pounds and would be ineffective but if the spring exerts aipressure of pounds, the'high cylinder pressure will be overcome by the spring and the low cylinder pressure so that the valve will be opened and the low cylinder prevented from becoming a dead element. In starting, the valve remains Vopen until the pressure built up in the high cylinder exceeds that built up in the low cylinder plus that exerted by` the spring, when it closes. Actual use of my device has demonstrated that there is no unfavorable reaction on the high pressure engine, but on the contrary, the engine is balanced and there is no slipping of the drivers. The increased eiciency of the low pressure engine more than offsets the decreased eiiiciency of the high pressure engine.

By supplying compressed air from the main reservoir of the air brake system or live steam under full boiler pressure through the pipe 49, the engineer may, at any time he desires, cause upward movement of the plunger 32 and opening of the valve 18 to supply live steamto the low pressure 'cylinder. lllhis will be done if, for any reason, the engine has had its speed reduced on account of low steam pressure so that it is about to stall, or under emergency conditions as for example, when increased load is imposed as on an up grade.

Having thus described the invention, what is claimed as new is:

1. An automatic starting and regulating valve for compound steam engines comprising a casing having means whereby the same may be connected to the live steam duct of a compound steam engine and provided intermediate its ends with a valve seat and a valve thereby forming a live steam chamber between said valve and said connecting means, said casing being provided with means whereby the same may be connected to the passage between the high and low pressure cylinders of a compound steam engine, and spring means assisted by the steam pressure in the passage between the high and'low'pressure cylinders for opening the ing a casing having means whereby the same may be connected to the live steam'duct of a compound steam engine and provided intermediate its ends with a valve seat and a valve thereby forming a live steam Chamber between. said valve and said connecting means, one side of said easing being provided with means whereby the same may be connected to the passage between the high and low pressure cylinders of a compound steam engine7 spring means assistedby the steam pressure in the passage between the high and low pressure cylinders Vfor opening the valve against the pressure of the live steam in said chamber when the pressure of the live steam in said chamber drops below the Combined pressure 'of'said spring means and the steam withinisaid passage, and a fluid pressure operated plunger carried by said easing in longitudinal alinement with lsaid valve for opening said valve irrespective of the steam pressures.

3. The combination with a compound steam engine having high and low pressure eyiinders with an exhaust passage connecting the high pressure cylinderY with the intalre of the low pressure cylinder7 of alive steam duet to the high pressure Cylinder, means connecting the exhaust passage and said duet and lincluding a cheek valve elosing in the direction of live steam flow and spring actuated toward the open position, whereby the high pressure Cylinder exhaust assisted by the spring tensionopens the valve t0 eed live steam to the low pressure cylinder when the steam pressure drops below a predetermined degree, and manually controlled means for opening said valve irrespective or the steam pressures.

ln testimony whereof I afliX my signature.

Janes B. vERNoN. [1.. 8.]

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