US524154A - Engineer s valve - Google Patents

Description

f .UNITED STATES 'PATENT Ormes.

WILLIAM C. WIIITACRE, OF S'I. LOUIS, MISSOURI.

ENGINVEERS VALVE.

SPECIFICATION forming part of Letters ratelt'No. 524,154, dated August '7, 1894. i VApplication tiled March 7,1893. Serial-No. 464,958. (No model.)

. is a full, clear, and exact description, such as will enable others skilled in the art to which my invention relates 4to make and use the same, reference being had to the drawings forming a part of this specification.

My invention relates to devices to be used by engineers on locomotivesfor controlling .t the motive'fluid for operating the brakes on trains in pneumatic brake systems, popularly known as engineers valves. More particularly, it-relates toan engineersvalve, the subject matter of 'an application filed by myself April 12, 1892, Serial No. 428,855-

allowed January 23,1893, and consists in features ofl improvement in the construction of the said valve and in the consequent method ofoperation.

\ In the practical operation of the engineers valve, the subject of the aforementioned application, it was found lacking in'some particularszf-It was found too sudden in its opcondition.

Vtion is to supplythese wants, and effect the vational view of the valve as a whole.

eration in the setting of the brakes, and there was no provisionfor partially settingthe brakes, not allowing the full pressure in the auxiliary cylinder to act, and maintain that The object of thepresent inven desirable consequent results.

In the accompanying` drawings, in which like characters of reference denote like parts in the several viewsz-Figure 1 is a side -ele- Fig. 2 is alongitudinal section, partly in elevation, taken o nra diameter corresponding to the axis of the operating cam shaft, or as on the line 2 2 in Fig. 1. Figs. 3 to 7' are similar longitudinal diametrical sections taken as on the lines 3-7 in Fig. 2, on a diameter at right angles to the operating cam shaft, illustrating in the different Iiguresfrespectively, the position of the coacting parts corresponding to the several positions of the operating handle; Fig. 3 being f or the position of the operating handle for emergency stop, Fig.

I 4 servicestop; Fig, 5, flap, Fig. 6 running, and Fig. 7 for f excess pressure.

Yation.

As already stated, in a general-Way, after the en gineers valve, the subject of the aforementioned application, was given a practical test, it was found that it could be improved on,'a'nd indeed, required some changes in the construction and consequent method of oper- Primarily, the escape of the air from the train pipe through Athe valve, was too sudden, causing a too sudden application of V the brakes, or rather, a too sudden setting and again, it was found advisable to often set the.

wasr practically impossible. In the presentmodel I have sought to provide for these extra requirements in 'the form of construction which I will nowvdescribe. 1 A represents an open ended cylindrical valve casing, bored out or otherwise formed t0 two relativelydifferent diameters, at least so that there is a middle portion of relatively smaller diameter than the two end portions,

making use of the shoulders formed by the relatively reduced portions, as at a and a', for

valve seats facing toward either end, respect# i ively. A

B represents aclosing cap piece screwed into the upper end of the casing A.

yC represents a cupshaped end extension of the casing A, being screwed at its comparatively closed end into the lower end ofthe t o. D represents a hollow plug-piece screwed casing! into the projecting end of the extension piece C, screw threaded on its projecting end adapting a connecting pipe from the. main reser l 'I l 95 central perforation providing a direct `corn`v l voir to be screwed thereto. The upper closed end of the extension piece C is formed with a municating opening from the space in the valve casing above it, with the hollow space below the same, and adapted'to receive a Ioo valve, described later, to control such open# ing, the lower circumferential vedge of .the

perforation being beveled o as at c to for 1 d r a seat for the sai-Jdvalve. The pieceQisal/g/ formed with a laterally extending opening N, (see Figs. 6 and 7) communication through which is controlled bya valve'therefor, to be described later, and a communicating duct C in the side wall thereof extending from the said lateral openingto the space in the valve casing above the piece C, around the direct central communicating opening already referred to. C" represents a screw-cap for closing the outer end of the lateral opening described, and for providing a housing for the valve therefor.

The inner end of the hollow plug piece D is formed as a skeleton web, in the center of which is formed a guide for the lower or guide end of the valve stem E of the winged, beveled an'ged valve F which is used to close the central opening in the upper end of the cup-shaped Aextension piece C.

F represents a coil spring surrounding the stem E for normally forcing the valve F to its seat c, to close the said perforation.

G represents a rod or shaft placed diametrically across lthe upper end of the valve casing A and having journalbearings formed therefoir in the side walls of the casing and secured in place by the screw g. One end is made to project beyond lthe casing, and has secured thereto the operating handle H. The handle H is provided with a spring pawl H' which is adapted, in the movement of the handlev I-l, about the axis of its rod or shaft- G, to engage in notches l, 2, 3, 4 and formed in the circumferential edge of the segmental pawl rack I, thereby determining the different set positions of the handle l-L rlhe pawl rackrI is `secured tothe side of the casin g A with itscurved notched edge concentric with the center of the axial shaft G, and to theshaft G, at approximately midway between the sides of the v alve chamber, is rigidly secured the double compound cam-piece K, which com prisessubstantially three cams in one-a central lone 7c, and two outside similar ones, see Fig. 2.

The casing A is formed with a lateral projection or nozzle A', the projecting end of which is screw-threaded to receive the end of.

the train pipe. This projection is hollowed or bored' out, affording a lat-eral port from the central or relatively reduced portion of the valve casing.

. In the side walls of the valve casing A are formed the several orificesor exit perforations P, from which communicate openings from the upper relatively enlarged portion of the valve casing to the exterior atmosphere.

In the lower relatively enlarged portion of the-valve casing is fitted a beveled flanged win ged main valve L for controlling communication from the main reservoir to the train pipe, which has an upwardly extending stem portion Z, and is normally held seated or closed by the coil spring L', iinding a bearing on the upper surface of the extension piece C. M is a valve similar to the valve L, lexcept that itis made with the additional feature corresponding to a piston, with packing in it to fit the upper relatively enlarged portion of the casing A, and is relatively inserted. The valve casing Mis also formed with a longitudinally projecting lug M which is faced o on a curve substantially concentric with the axis of the cam shaft G, adapted to be engaged by the surfaces of the cams lc. The valves L and M, and their respective stems G and m are concentrically bored out longitudinally to accommodate the upwardly extend ing valve operating stem E of the Valve F, which is'preferably ofa length sufficient to normally project somewhat above the operative surfaces of the lug M and between the same (see Fig.. 2). The upper end of this valve stem Eis adapted to be engaged and operatedby the middle cam surface la of the cam block K.

Into the laterally extending perforation N in the side wall of the extension piece C, is fitted the bevel ended cup valve O which is provided with a valve seat p formed by diametrically reducing the inner of the perforations, and is normally held closed by the internally disposed -gaged coil-spring O (see Fig. 4t) vwhich finds an end bearing against the inner surface ofthe closing screw cap C".

The cam surface 7c comprisessubstantially a cam with tive relatively diametrically different stepped faces by which means the valve M can be given five relatively different positions corresponding toas many dilferent positions ofthe operating handle H, as determined by allowing the spring operated pawl to engage in the dierent notches 1 to 5 in the pawl rack I. Two of these relative-longitudinal movements of the valve M are effected by the inclination of the cam surface between two diametrically different concentric portions (see Figs. 4 and 6).

The cam'lc consists in a simple one-place cam projection at one point on a concentric hub portion, which engages with the projecting end of the valve stem E to depress the same longitudinally, and operate the valve F, in one of the extreme positions of the operating handle H (to the extreme left inv Fig. 7, the right in Fig. 1). The position of this cam lug on the cam lc relative to the operative faces of the cam 7c is such that it is in engagement IOO with the valve rod E when the cam surface of the cam 7c of the longest radial dimensions in engagement with the valve lug M to seat the valve M, for reasons that will appear in the following description of the method of operation of' my improved device.

The drawings (Figs. 3 to 7 inclusive) are almost self-explanatory of the method of operating the valve in train service, the co-relative position of the several parts being shown in the several figures, and the flow of the vmotive uid consequent in such positions, being indicated by the small arrows.

The stems m and l of the valves M and L, are of such length that they will abut against each other, and in that way hold one of the valves M or L away fromxits seat at all times,

and when the lower orspringseated valve L is closed, the piston part of thevalve M will close the perforations P, as shown in `Fig.'5.

' While the valves are in this position, a lap position as it is termed, the valve M can be forced down to unseat the valve L, without unv of the valve F. This causes the Valve L to seating the valve F, and thus cause the parts to assume a .running position, as shown in Fig. 6, or one in which the relief valve O will permit the excess pressure in the main reservoir to pass into the train pipe. The different positions assumed bythedilerent valves as shown in the drawings, may be classified as follows: l f

In Fig. 3, where the handle H is to the extreme right, the cam faces 7c and lo are away from the lugs Mi and theoperat-ing stem E seat itself by reason of the pressure from the main reservoir, beingat Vits back (this pressure obtaining access to the back of the valve through the port C', if it is great enough to compress the spring O) and the pressure of the spring-L. .The valve 4M in 't'nis.instance, being free to move up, will doso by reasono f the back pressurefrom the air in the train pipe, which will not only unseat the valve from its seat a, but will cause its piston portion to pass beyond the exit ports. P, and` therebyopen communication from the train pipe Vto the exterior atmosphere. This will reduce the pressure in the train pipe to .atmospheric pressure, which will cause the brakes to be applied quickly andsuddenly. This position I term the emergency stop.

. In Fig. 4, the handle H has been moved one notch toV the left, thereby bringing the Vfirst fluctuation in the cam faces k into contact with the lugs M which will slightly depress the valve M, without changing the positions of the valves L, Fand O. We will assume, in describing the eiect of this position of the handle, that the train pipe has v been previously charged, and that this position hasV just been taken. IThe valve M in this instance is raised from its seat a, by the back pressure in the train pipe, and but partially uncoversthe exit ports P, which will jf fpermit a gradual escape of the air, therebyV p p. so,

causing a slow reduction'of the pressure in the train pipe, consequently 'the application of the brakes is slow and gentle. This position, I term the service stop.

In Fig. 5, Where the handle H occupies a central position, the rst fluctuation on the cam surface lo is in engagement with the lugs M .and has caused the piston portion of the valve M4 to entirely coveror lap the exit portsr P, thereby preventing the escape of air therethrough, and as the cam surface k has not yet reached the operating rodE for the valve F, and as the stem 'm of the valve M but lightly rests upon the stem Z- ofthe valve/L, the valves L and F are seated. These positions of the different valves will prevent the passage of the air therethrough in either direction, and is termed a lap position.

'stem E, but has not depressed it. surface 7c, has by its second fluctuation, forced y 4it, the brakes are released, reservoirs recharged.

located above the first In Fig. 6, the handle H occupies a position slightlyto the left, and the cam surface k has just come into contact with the piston The cam the valveM downwardly, and by theabutment of vits stem m with the 4stem l, of `the valve L, has unseated said valve partially,

thus permitting the excess pressure in the 'main reservoirto low through the port C',

past the valve L, into the train pipe, thus raising the pressure of the lat-ter to-that of themain reservoir. Of course it will be u nderstoodin this connection, that the valve O is set to resist being unseated vuntil a certain l pressure is v reached in the main reservoir. This, I term the running position. n

In Fig.7, the handle H has been turned to its extreme left position, forcing the valve M downward, by reason of its cam which valve byvits contacting, or abutting stem, further unseats the valve L, andestablishes an easy communication between the train pipe,.and the space behind, the valve. The cam surface 'c has also forced the rod E- snrface 7c,

downwardly, and has unseated the valve F,

which opens communication between the main reservoir and the train pipe without the interposition ofthe relief valve O. This; I term apposition of excess pressure and by Having thus describedmy invention, what I claim, and desire to secure by Letters Patent, is-

l. In an engineers valve, the combination with the valve casing having communication with a main reservoir, train pipe, and the eX- terior, of a valve for controlling the communication between the train pipe and the exterior atmosphere, means for operating said valve, a v ,valve for controlllng communication between the main reservoir and the vtrain pipe, said latter valve being operated by the-abutting contact of the first named valve when the same is operated, substantially as described.

2. In an engineers valve, the combination with the valve casing having communication with the main reservoir, train pipe andthe exterior atmosphere, of a main valve for controlling communication between the main reservoirand train pipe, a valve for controlling communication between the train pipe and the exterior atmosphere, a handle proand the auxiliary IOO IIO

vided with a cam surface for operating the last named l valve, which valve operates the valve which controls the communication between the main reservoir and train pipe, substantiall y as described.

3. In an engineers valve, the combination 4 with the valve casing having communication with a main reservoir at its lower end, a valve for controlling the passage .of the air from the main reservoir to the train pipe, a valve trolling communication between the train pipe and the exterior atmosphere, said last named valve for connamed valve being independently operative n `from the valve which controls the communication between the main reservoir and train pipe, and which is `adapted to operate said rst named Valve yby its contacting stem, and means for operating said valve,vsubstantially as described.- 4

4. In an engineers valve, the combination with the Valve casing having communication with the main reservoir,train pipe and eXterior atmosphere, of a Valve F' and its stem,

which valve establishes free communication between the main reservoir and the train pipe in conjunction with a main nValve LVV with the main reservoir, train pipe and the exterior atmosphere, yof a main valve Vforcontrolling communication between thereservoir and the train pipe, a relief valve located between said main valve and fthe mai-n reservoir, an .excess pressure valve located between the main valve 'and the main reservoir, a stem on said valve, a piston valve slidingly mounted on said stem for controlling the reduction ofthe pressure in the train pipe, and cam surfaces foroperating the piston`valve (which in turn operates the main controlling valve between the reservoir and the train pipe in certain of its positions) and the excess pressure valve, substantially as described.

In. testimony whereof I -hereuntoaix my signature, in presence of two witnesses, this 18th day of December, 1893. WILLIAM C. WHITA'CRE.

Witnesses:

F. R. 'CoRNwALm HUGH K. WAGNER.

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