US1465645A - Strickland l - Google Patents

Description

' Aug. 21, 1923. 1,465,645

' S. L. KNEASS VALVE Filed March 5,

Patented Aug. 21, 1923.

{UNITED STATES CORPORATION OF PENNSYLVANIAQ STBICKLAND L. KNEASS, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO WILLIAM SELLERS & COMPANY, INCORPORATED, OE PHILADELPHIA, PENNSYLVANIA, A

; VALVE.

Application filed "March 3, 1922 Serial No. 540,741.

To all whom it may concern." Be it known lit-hat I, S'rmoKLAND L. Thames, a citizen of the United States, re-

siding at Philadelphia, county of Philadel 5 phia, and State of Pennsylvania, have invented a new and useful; Improvement in Valves, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form apart of this specification.

This invention is directed to animprOvement in valves, and more particularly re lates to drifting valves for locomotives.

It hasbeen found advantageous in operating locomotives on down grades to admit an amount of steam to the cylinders insufiicient' to add a propelling force to the pistions, but suilicient to prevent cutting of the sliding surfaces and the, admission of air tending tothe oxidation of the lubricating oil at the ends of the pistonvtravel, all of which is well known in railroad engineering practice. p v

One of the objects of my invention isto provide a simple and efficient valve of this character by which the amount of steam admitted to the cylinder is confined within fixed predetermined limits beyond the judgment of the engineer or fireman, This I accomplish by providing a valve which is always shifted to either its fully open or ,fully closed position and cannot remain in stable position in an intermediate position.

Another object of my invention is to provide .avalve which is self-seating and gravity-actuated so that if excess pressure oc- -curs in the pipe connecting the valve to the" cylinders, the valve will be raised to relieve said pressure'and be automatically returned 40 to its seat without attention on the part of the operator. v

x Still and her object of my invention is to "provide .a quickly opening valve whereby the require amount ofsteam can be instantly delivered to the cylinders to prevent damage immediately after the. main ,steam supply is cut off also'a valve having ample area to supply the necessary amount of steam hile drifting, aS well as operating so arranged as to require the minimu a ,amount of effort on'the part ofthe opera-ton to quickly open the valve againstthe high mechanism for opening and closing the VillVQ steam pressures now carried by locomotive boilers.

t still further object of my invention is to arrange the valve andv its operating mechanism so that the valve is moved sub stantially rectilinearlyand friction and wear on the bottom of the valve and the guiding parts thereof'are avoieed, and-the valve is thereby permitted tolift and seat easily, as well as seat squarely'on its seating surface.

. The above objects are accomplished by providing a simple form of casing in which is mounted a gravity-actuated valve provided with guiding means at the top and bottom, and which is opened against the steam pres: sure so that the valve is held to its seat under normal conditions. As the valve is held to its seat under normal conditions, all danger of the valve permitting a continuous flow of steam to the cylinder is. eliminated, when it is opened by accidental means, such as excessive compression within the cylincers, which might tend to cause an accumulation of steam pressure in the cylindersand produce a gradual increase of pressure sufficient to move the locomotive forward or backward from a standing position and cause an accident.

'The valve actuating mechanism com arises a lifting lever pivotally mounted in the cas the receiving and deliveringchambers in the alve body. .As the lift of the cam gradually increases from thebeginni'ng toward the end of the movement thereof, a compare tively large arc of travel of the operating lever is required for the initial valve lifting movement of the cam, the arcof travel of the operating lever. decreasing as the valve is continued to be'lifted, thereby providing the maximum lifting power and slowest speed of valve movement when the valve is under the greatest pressure and an increasing speed of valve movement and reduced power as the pressure on the valve decreases. This increase of valve movement and decrease of power are enhanced by the circumstance that at the beginning of the valve-lifting movement, the cam 24 contacts with the free extremity of the lever 18 and that, as the valve lifts, the point of contact between'the ca-nrand the lever shifts toward the pivot of the lever.

A still further object of my invention is to provide a valve in which the velocity of the steam passing through the valve controlled opening is reduced below that at another portion of the valve body, so as not to cause undue wear on the valve seat and valve guiding surfaces. This is accomplished by interposing a restricted area in the valve body, preferably in the outlet, which throttles the flow of steam.

Theprecise nature of my invention will best be understood by reference to the accompanying drawings, which will now be described, it being premised, however, that various changes may be made in the details of construction without departing from the spirit and scope of mv invention as defined in the appended claims.

Fig. 1 of the drawings is a vertical section through the valve body.

, F 2 is a similar view at right angles to Fig. 1.

Fig. 3 is a sectional plan view on the line 3-3 of Fig. 2.

In these drawings, the reference character 5 designates the valve body, 6 the inlet opening, and 7 the outlet opening which is restricted as clearly shown in Figs. 1 and. 2. Both the inlet and outlet openings are provided with threaded portions for coupling the valve body to the steam line. 8 designates the septum in the valve body which separates the receiving chamber 9 from the delivery chamber 10, and is provided with a passage 11 having a cylindrical wall and an annular valve seat 12. 13 is the valve controlling the passage 11 and having downwardly extending guiding members 14 which engage the walls of passage 11. The valve is also provided with an upwardly extending guiding member or stem 15,-which is sage are machined, and through which the valve member is inserted into the body.

Pivotally mounted in the delivery chamber 10 on a pin 17 seated in orifices in the walls of the body is a lever 18, the free and in its gland 20 threaded therein, and i in a bearing 21 in the opposite wall of the body, is a spindle 22. 23 is a cam connected to the spindle 22 having a curved surface 24 in engagement with the lower face of lever 18. I This cam 23 is provided with a tail piece which is arranged to'engage one side of a stop lug 25 when the valve is open as shown in Fig. 2. 26 is an operating lever connected to the spindle 22 and which is shifted from the full line position to the dotted line position, as shown in Fig. 2, when the valve is closed; and when the valve is in its closed position the straight portion of cam 23 will engage the upper face of stop lug 25.

The are of movement of the lever 26 from one position to the other is approximately ninety degrees and the parts are so positioned with relation to each other that the lever is at approximately forty-five degrees from the vertical when the valve is in either of its positions,so'that the parts are always maintained in their shifted positions by the weight of the lever and by fluid pressure, holding the valve against its seat, or against the lever 18 when the cam 24 is in stable position relative to such pressure.

The curved surface of the cam 24 is so arranged about the axis of the spindle 22,

that the radius of its point of contact with the lever 18 varies from a minimum when the long axis of the cam is in a horizontal or inoperative position to a maximum when the long axis is about vertical and the valve is fully opened as shown in Fig. 2. When the valve is in this position, the operating mechanism is in stable position, preventing accidental closing of the valve.

When it is desired to close the valve, the lever 26 is shifted from the full line position to the dotted line position, in which position thecam 23 will contact withstop 25 and arrest the further movement of the lever 26 in a clockwise direction.

lVhen lever 26 is in the dotted line position, the valve 18 will be seated on its seat.

12, and the lever 18 will rest on cam 23, while the upper face of lever 18 will be clear of the lower faces of the valve guiding members 14.

ll hen it is desired to open the valve, the lever 26 is shifted from the dotted line posi tion to the full line position. During the first movement of cam 23, lever 18, which raises the valve, is moved but slightly for a long are movement of lever 26 so that the leverage for raising the valve from its seat while under full boiler pressure is very great, but as the lift of the cam due to the eccentric curvature thereof rapidly increases and the area of the passage 11 is relatively large, the valve will be quickly opened to a sufficient degree after it has been raised from its seat to provide a free passage for the steam and relieve the pressure on the top of the valve.

By the interposition of lever 18 between the cam 23 and the valve, the lifting pressure upon the valve is always in the line of its axis, while the guides for the valve are so arranged that pressure of entering steam is ineffective to produce lateral movement of the valve.

The advantages of my invention result from the provision of a quick opening valve, which is arranged to be shifted to and maintained only in its fully opened or closed position, and in which the mechanism is so arranged that leverage of the valveopening means is relatively great when the valve is initially moved from its seat, but rapidly decreases as the valve moves farther away from the seat. A further advantage results from the provision of a valve in which the velocity of the steam passing through the valve controlled passage isless than the velocity of the steam passing through other portions of the valve body, so that the cut-- ting action of the steam on the valve guides and seat is reduced to a minimum. other advantage of my invention results from the provision of meansto prevent any tilting of the valve to cause its axis to deviate from parallelism with its direction of movement.

Having now fully described my invention, what I claim and desire to protect by Letters Patent is:

l. A hand operated locomotive drifting valve comprising a body, a septum dividing the body into a receiving chamber and a discharge chamber and provided with a pas-' discharge chamber and provided with a passage, a gravity check valvecontrolling said passage, guides preventing lateral displacement of the valve by fluid pressure, and valve opening mechanism situated in the discharge chamber and comprising a cam and a pivoted lever adapted to be operated by said cam and transmit rectilinear motion to the valve, a hand lever for operating said cam, the cam surface being so shaped that a comparatively large are of travel of the hand lever is required for the'initial lifting movement of the valve and the arc of travel of the operating lever decreasing as the valve is continued to be lifted.

3. A hand operated locomotive drifting valve forcontrolling the flow of steam, comprising a body having a receiving chamber with an inlet thereto and a delivery cham her with an outlet therefrom, a septum between said chambers with a passage extending therethrougli, a valve controlling said passage, guides for the valve preventing its lateral displacement by fluid pressure, and hand actuating mechanism for the valve, the outlet from the delivery chamber being of smaller effective area than the passage between the chambers.

4. A hand operated locomotive drifting valve comprising a body having a receiving chamber with an inlet thereto and a delivery chamber With an outlet therefrom, a septum between said chambers with a passage extending therethrough, a valve for controlling the passage in the septum, a hand actuated cam for raising the valve to open said passage, a lever interposed between the cam and the valve member to cause the lifting'pressure to be solely in the direction of the valves axis, and guides to prevent lateral movement of the valve under pressure of the entering steam.'

I testimony of which invention, I have hereunto set my hand at Philadelphia, Pa, on this first day of March, 1922.

STRICKLAND L. KNEASS.

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