US1351168A - Drifting and by-pass valve - Google Patents

Description

c. u. HILFERTIK. DRIFTING AND BY-PASS VALVE APPLICATION FILED NOV. 8, I917.

Patented Aug. 31, 1920.

'3 SHEETS-SHED I.

C. D. HILFERTY.

DRIFTING AND BY-PASS VALVE.

APPLICATION FILED NOV. 8, 1917.

1, 35 1 1 68. t nted Aug. 31, 1920.

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DRIFTING AND BY-PASS VALVE.

APPLICATION HLED NOV. 8, m2.

Patented Aug. 31,1920,

3 SHEETS-SHEET 3.

P721] CA'IFZEJ-R/V/ZFEFTY avwewto c $51 attoawwi are ST? lF'l 'ltZE.

CHARLES D. HILFIJRTY, OF YONKEBS, NEW/V YORK, ASSIGDIQR TO LGCOMOTIVE SUPER- I'IEATER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

nnrr'rme am) nr rass VALVE.

Application filed November 8, 1917.

To all whom it may concern:

lie it known that 1, CHARLES D. l'lILFER'lY, of Yonkers, New York, have invented certain new and useful Improvements in Drifting and By-Pass Valves, of which the followin is a specification.

My invention relates to locomotives and has particular reference to the class of valves known as drifting valves which are used. on. locomotives. ln my invention I combine valve of this kind with a by-pass valve, 0., a valve capable, under certain conditions, of establishing communiaation between the two ends of the cylinder. 1

provide by my invention a practical means of admitting drifting steam and cutting it off, and simultaneously respectively opening and closing'the by-pass. I further provide an improved mechanism for automatically cutting off the drifting steam and clos ing: the hvpass when the engine is at rest. Other objects of my invention will appear as the description proceeds.

To urulerstand the invention a reading of the following description in connection with the acconn ianying drawings till he sutiicicnt. in these drawings Figure 1 represents my invention applied to a locomotive, only as much of the latter being shown as is required to show the relation of my device to the parts of the locomotive;

Fig. 2 is an enlarged sectional view of a part of my device, the section being on line ill ll of Fig. l;

Fifi. -3 is a sectional detail on a. still larger section line being the same as in on l ne l r" of Fig. 1.

Figs. 5 to 5) show a 110(lltiCflt1011,F1g. 6 view showing the device applied to Fig. 7 showing the drifting and lrr-passvalve in longitudinal central section; 8 and 9 showing sectional lQTYS. ta n thmuejh the axis of the central vrlve and at ri ht angles to each other.

and 9 are on a larger scale than Figs. 10 and 11 are two central longitudi- Specification of Letters Patent.

orally. 2

Patented Aug. 31, 19%).

Serial No. 200,920.

nal sectional views taken at right angles to each other of a modified form of the control val ve;

Referring first to the form of my invention illustrated in Figs. 1 to 5, there is shown in Fig. 1 my device attached. to a locomotive, only as much of the latter be ing shown as is required to show the mannet of attachment and working. Reference numeral 1 refers to the valve casing genis the locomotive boiler, and -'l a re the cylinder and valve chest respectively, 5 is the link of a alve gear. These parts are of the ordinary or any preferred con struction. The two ends of the cylinder are connected to each other by means of the by-pass GG, the two parts ot which lead from the two ends of the cylinder to the va ve casing l. Also connected with this alve casing is the pipe '7, its other end being connected to the steam space of the boiler. 8 is a globe valve in this pipe, while 9 a from Tr'lJCll a branch pipe corresponding to 7 leads to a valve casing corresponding to 1 and located on the other side of the locomotive.

it will be understood that while in the following description and in what has preceded reference is usually made to only one cylinder, one valve chest, one drifting valve, etc., there are correspondingduplicate parts on the opposite side of the locomotive.

The stems ilk-10, which will be more fully referred to farther on, are acted upon by a yoke 11, which, in Fig. 1, is shown in section. This yoke 11 is attached to rod 12, the latter being securedcby means of a pin to the link 12, which in turn is similarly connected with the rocker 1 which is pivoted at 15. The other end of this rocker is connected through the rod 16 to the link 5.

Valve casing 1 is connected by means of the pipe 1? to the valve chest.

Valve casing 1 has in its upper portion (see Fig. 2) the cylindrical bore 18 with the ports 19 and. 20, with which latterthe pipes (3 6 of the by-pass communicate. The c vlindrical here 21, considerably larder than here 18, is coaxial with the latter, and the curl ton valve, 6. c, the portion lying in the bore "18 is hollow and has cut into it a circular series of port openings 23. The proportions of the parts ust described are such that when the piston valve 22 is in its upper p0- sltion, as in Fig. 2, the port openlngs 23 are closed, but when the valve-1s 1n 1ts lower position, these openings register with port- 20, and the upper edge 24 of the hollow valve is about flush with the lower edge of port 19.

A small opening 24 connectsthe hollow interior of the upper portion of the valve with the space 25 below the large piston 22,

while the small opening 49 leads to the at-' the lower of these cylinders on an enlarged scale. The cylindrical interior is of one diameter forabout half of its length and of a slightly different diameter for the remaining distance, resulting in shoulder 33. These two cylindrical portions and the opening which accommodates stem 10 are in axial alinement. Seating on shoulder 33 is the valve 34, which has an extension 35 toward the left, as viewed in Fig. 3, which fits slidably in recess 36 in cap 31. A spring 37 engages the inner side of the cap 31 and the opposing surface about 34, tending to keep the valve seated. On the opposite side of valve 34 there is the extension 38 connected to which is the small piston 39 which has a slidin fit in the smaller part of the cylinder. Extending through this piston are holes 40, of which two are shown though there may be any desired number. Stem 10 is integral with the remainder of this piston valve structure. For a small distance it is of a slightly enlarged diameter, forming shoulder 41. Spaced slightly from this shoulder is the annular groove 42. Clamped between the shoulder 41 and a split ring 43, which is sprung into groove 42, is the annular disk 44. Slidable on the enlarged portion for the small distance between piston 39 and disk 44 is the annular disk 45, which acts as a check valve, closing the openings 40 when it is contact with piston 39.

The description of the details just given in connection with the cylinder illustrated in Fig. 3 applies substantially to both cylinders 27 and 28.

Connectingthe space 25 with the space above valve 34 in cylinder 27 is the opening 46. in cylinder 27 with the space above valve 34 in cylinder 28 is the opening 47. The space Connecting the space below valve 34' in cylinder 23 below valve 34 is connected with the valve chest 4 through opening 48 and pipe 17.

The opening 24 which is located so it will be uncovererd by the upper edge 24 of the piston valve 22 when the valve is in its lower position, is connected by pipe with the lubricator choke plug 72 which is somewhat modified for. the present purpose. 71 is the ordinary oil or tallow pipe, which also connects with choke plug 72. The choke plug is screwed into the walls of the main steam passage at any suitable point. The steam discharge end 73 of the choke plug 72 is bent so that it lies at right angles to the tallow discharge end of the choke plug and faces toward the steam chest valve.

The operation of the form of the device described this far is as follows:

The locomotive being in motion, link 5 oscillates about its pivot, and this oscillatory motion is imparted to rocker 14 by means of the rod 16, and rocker 14 in turn imparts a reciprocatory motion to rods 12 and 12, the latter bearing yoke 11 at its end. The parts are shown at about their mid-position. As they move as described, the two branches of yoke 11 alternately come into contact with the two stems 10. It will be noted that the dimensions are such that the two stems 10 can never be engaged by the yoke at one and the same time. \Vhen the yoke moves one of the stems 10 inward, spring 37 is compressed. Valve 34 is lifted from its seat, any fluid above piston 39 is free to pass through openings 40 in that piston, lifting disk valve 45 off its seat and passing around the edge of disk 44. lVhen the yoke 11 performs its return stroke, and no longer engages the end of stem 10, the spring 37 forces valve 34 back toward its seat; but whatever fluidhas passed through openings 40 will be trapped as valve 45 seats. It escapes comparatively slowly pastpiston 39. The speed with which it escapes depends mainly on the strength of spring 37 and the closeness of fit between piston 39 and the wall of the cylinder. These are so arranged as to keep the valve 34 from seating at'all during all butthe very slowest speeds of the locomotive. The result is that during running at any but the very lowest speed, there is continuous communication of chamber 25 through opening 46, the larger and smaller chambers of cylinder 27, opening 47, larger and smaller chambers of cylinder 28, outlet 48, and pipe 17' with the valve chest. Evidently spring 37 can be made of such strength and lit of piston 39 of such snugness that the speed of the locomotive at which the openings of valves '34 no longer overlap may be any predetermined low speed desired, within reasonable limits.

Valve 8 is normally open. Steam through pipe 7 reaches the chamber in the hollow upper portion of piston valve 22, and leaks through the small opening 24k into the lower chamber 25. The resulting pressure on the lower side of the piston valve 22 overbalances the combined steam pressure and air pressure admitted through opening d9 on the upper side, and the valve will remain in its upper position.

W hile running above the predetermined low speed referred to above, chamber 25 will be in constant communication with the valve chest, as stated; as long as the steam chest pressure does not fall below a certain predetermined amount, which can evidently be fixed by giving the proper proportions to the surfaces of piston valve 22, the latter remains in its upper position, keeping the by-pass closed and the drifting steam supply shut oil.

hen the pressure in the steam chest drops below the predetermined point referred to, due to partial or entire closing of the throttle, steam escaping from 25 through passages 1:6, 4:7, etS and 17 to valve chest permits valve 22 to assume the lower position. The opening 2%, it should be here pointed out, is made materially smaller than the outlet to the steam chest, so that steam pressure in cannot materially exceed steam pressure in the valve chest l.

Vith valve 22 in its lower position, communication is established between the two ends of the cylinder 3 through by-pass 66,

and at the same time steam from the steam space coming through pipe 7 is free to flow to either end. This will effectually prevent the formation of any vacuum in the cylinder.

lVhen the locomotive has come to a standstill, it is impossible, as will be understood from the description given above, for both valves Set to be open. Either both, or at least one, will be closed; and pressure will therefore at once build up in chamber 25 by steam leaking through small opening 2%, valve 22 will be forced into its upper position. drifting steam from pipe 7 and communication through by-pass 66 being cut off. No danger therefore exists of the engine beginning to move. The valve remains in this upper position until the locomotive again begins to drift.

If for any reason the passage from chamber 25 to the valve chest 4 should fail to close when the engine stops, the two ends of the cylinder are in free communication and no possibility exists of unbalanced pressure or the piston building up on either side sufficient to move the engine. This is a safeguard not existing in previously known drifting valves.

Referring to the oil supplying apparatus, the ordinary method of supplying oil to the steam chest fails to deliver oil to the bearing surfaces of the valve, etc., when the steam supply from the throttle is insufficient to convey the oil from the choke plug to the bearing surfaces. lVith my improved device a limited amount of steam will be supplied for this purpose through opening 2i", pipe 70, and discharge port whenever steam chest pressure is low enough to let valve 22 drop into its lower position. This steam supply, passing across the open end of the tallow pipe, carries the oil, fed from the tallow pipe, to the steam valve, etc.

Another form of my device is shown in Figs. 6 to 9. The valve casing l is here shown in horizontal position. The difference in diameter between the two cylindrical portions of the piston valve 22 is shown here as less decided. Otherwise the con struction of this valve is closely similar to the one first described. Steam is delivered to it at the left and passes, when the valve is open, through ports 19 and 20 to the steam ports 69 and 69 of the cylinder through pipes 6-6. The valve 22 will be held in the position shown in the figure whenever the pressure in chamber is sensibly near that on its other side. 50 is a bracket by means of which the valve casing is secured to the smokebox wall or other convenient support.

In place of the mechanism used in the form first described for insuring the closure of valve 22 upon the stopping of the locomotive, I here provide the control valve, shown at 51, and represented to a larger scale in the two sectional views of Figs. 8 and In the casing 52 of this control valve there is piston valve 53, the upper enlarged portion 54: of which reciprocates in the larger chamber. 55, while its lower stem portion 56, of smaller diameter, extends into the cylindrical. chamber 57, coaxial with 55. Fora short distance below the piston 53 the stem 56 is of reduced diameter, as at 58. Also extending through the lower part of the casing 52 is the duct 59, which leads into chamber 55 and has located in it the check valve 60. This check valve opens outwardly from and is pierced by a small hole 61.

Duct 62 leads to the atmosphere from the chamber 57, its inner end being so located that it opens into the annular s:-aee around the reduced portion 58 of stem 56, .when the valve 53 is in its lower position, but is closed by the stem when valve 53 begins to rise.

Annular port 63' connects by means of passage 64 and pipe with chamber 25.

A small bleeder 66 leads from port 63 to the lower surface of stem 56. Chamber 57 is connected to one of the steam ports of the engine cylinder by means of pipe 67, opening into it at 68. This answers as well as tapping it into the steam chest, as the vacuum produced by the moving piston during drifting exists first of all in the cylinder.

The operation of this form of the device may be described as follows. IVhen the locomotive is running normally, with the throttle open, steam from steam port 69 passes up through pipe 67 and duct 59, leaking through the small hole 61 in check valve 60, and fills chamber 55. This steam pressure keeps control valve 53 in its lower position against steam pressure on the lower end of stem 56 and air pressure on the lower annular surface of 54. The valve in casing 1 is kept in its closed position, as in Fig. 7, by steam pressure in chamber 25, which steam has leaked in through small passage 24, the opposing steam pressure on the valve acting on a smaller surface. 1

.VVhen now the engineer shuts the throttle, and a vacuum forms in the cylinder, the steam in chamber 55 immediately leaves by way of passage 59, with the result that valve 53 is raised by atmospheric pressure. This establishes communication between chamber 25 and space 57 by way of pipe 65, passage 64, and port 63. The steam in 25 then escapes, and escapes faster than opening 24 allows fresh steam to leak in, with the result that the reduced pressure on the right is overcome and valve 22 moves to the right. This puts the two ends of the main cylinder into communication and also allows drifting steam to be supplied, as in the first form of the device.

As a matter of fact, there is not, during drifting, anything like a constant condition of vacuum in the cylinder port passage. As the piston approaches the end of its stroke, the main valve is closed, and the pressure runs up. This pressure, however is not quickly transmitted to chamber 55, because check valve 60 operates, and allows only a very small, gradual leakage through opening 61. Before any appreciable amount of pressure can accumulatein 55, the plston, on its return stroke, is again creating a. vacuum and relieves this pressure, In eifect the action is that of pumping out pressure from chamber 55, with a small seepage back through 61.

The function of bleeder 6G is to drain away any water and obviate the danger of freezing. It is of course made small enough so it does not conduct enough steam away from chamber 25 to influence the action of the apparatus.

The modification of the control valve shown in Figs. 10 and 11 substitutes a diaphragm 70' for the piston 54. Stem 56 moves with this diaphragm, and the action is identical with that of the 'form in Figs. 8 and 9.

In the case of locomotives having more than two cylinders, it will be understood that each cylinder may, if cons dered advisable, be equipped with my device. I

- lVhile I have in the above fully described only two principal forms of device for carrying out my invention, other modifications arereadily seen to be possible, and willbe made in practice. These, however, inasmuch as they come within the spirit of my invention, are meant to be covered by the terms of the subjoined claims.

lVhat I claim is:

1. In a locomotive, the combination of a valve chest, a main engine cylinder, a bypass connecting. its two ends, a conduit connecting the bypass with the. locomotive steam space, a differential piston valve for controlling the by-pass and for shutting off communication from the conduit to the bypass, pressure on the smaller and on the larger areas of the piston valve tending to open it and to close it respectively, and means to subject the smaller area to live steam pressure at all times, and the larger area to a pressure substantially equal to valve chest pressure while the locomotive is moving above a low pre-determined speed and to live steam pressure when moving below that speed or standing still.

2. In a locomotive, the combination of a valve chest, a main engine cylinder, a bypass connecting its two ends, a conduit con necting the bypass with the locomotive steam space, a differential piston valve for controlling the bypass and for shutting off communication from the conduit to the bypass, pressure .on the smaller and on the larger areas of the piston valve tending to open it and to close it respectively, means to subject the smaller area to live steam pressure at all times, means to subject the larger area to a pressure substantially equal to boiler pressure at times when the engine is moving below a low predetermined speed or standing still, and means to cut this latter pressure down to substantially valve chest pressure during drifting above said low speed. j

3. In a locomotive, the combination of a valve chest, a main engine cylinder, a bypass connecting its two ends, a conduit connecting the bypass with the locomotive steam space, a diiferential pistonvalve controlling the by-pass and the communication from the conduit to the bypass, pressure 011 the smaller and on the larger. areas of the piston valve tending to open and to close it respectively, means to subject the smaller area to live steam pressure at all times, aconduit connecting the large differential cylinder to the valve chest, a valve in said conduit, means to open said valve periodically in definite time relation to the strokes of the main piston, and resilient means to close said valve.

4. In a drifting mechanism of the class described the combination of a differential piston valve comprising a piston movable in a chamber, a conduit connecting the chamber wit-h the steam chest, two valves in said conduit, means to open said valves successively, and means to close them eompai atively slowly.

o. in a mutt/111g mechanism of the class described the combination of a differential plston valve comprismg a plston movable in a chamber, a eonclult connecting the chamber with the steam chest, two Valves 1n said conduit, automatic means to open them comparatively quickly and to close them comparatively slowly, so that at all speeds 10 of the locomotive above a predetermined one each valve is opened before the other closes.

CHARLES D. HILFEBTY.

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