US679051A - Gate-valve. - Google Patents

Description

No. 679,o5|. Patented July 23, lem.

A. M. HEWLETT.

GATE VALVE.

(Application fil-ed May 27, 1901.) (No Model.)

:T HEZZ 7 MJJZEEEES 7,6,

NITED STATES PATENT .L Etc.,v

GATE-VALVE.

SPECIFICATION forming part of Letters Patent No. 679,051, dated July 23, 1901.

Application tiled May 27, 1901.

To @ZZ whom t may concern.-

Be it known that 1, ALFRED M. HEWLETT, a citizen of the United States, residing at Kewanee, in the county of Henry and State of Illinois, have invented certain new and useful Improvements in Gate-Valves, of which the following is a specification, reference being had to the accompanying drawings.

One of the leading objects sought to be attained in the manufacture of all gate-valves is a construction whereby such valves can be readily and quickly opened and closed without liability of the disks or valves proper sticking to or grinding against their seats during the entire movement of said disks. Such a construction is highly desirable, especially where the valves are employed to control the iiow of fluids under high pressures, for in such cases an apparently slight scratch or defacement of the acting faces of the said disks or their seats often results within a short time thereafter in a leak. The two disks that are employed in valves of this description are sometimes formed together from a single piece, their acting faces being wedge-shaped and the seats therefor correspondingly inclined. This construction is objectionable owing to the extreme care that must be exercised in properly securing the stem by which they are actuated, as it is evident that such stem passing through a screwthreaded cap or bonnet must Vbe held rigid, and of course the disks attached to such stem must fit exactly or wear of the parts will at once take place. It is more common, therefore, to form such disks in separate pieces, the faces of whichA are inclined or straight, and provide means for forcing them apart and against their seats as their actuatingstem is turned or forced down. Many of these constructions are objectionable in that they do not always permit the disks to loosen between the seats while being moved and in consequence are scratched or marred with the'results above specified. This contacting of the disks with their seats in the forms of construction last referred to is frequently due to the temporary sticking to the disks of the device employed to wedge them apart at the commencement of the upward movement of the disks.

It is one of the objects of my invention to Serial No. 62,098. (No model.)

provide improved means for securely'forcing said disks against their seats without any rubbing or grinding taking place between them and their seats.

A further object is to provide an improved construction ofi-valve by which, when it is desired to open the valve, the locking or spreading devices will release said disks from pressure-contact against their seats before they are given an upward pull.

Another object of the invention is to provide improved means for raising the disks.

These objects I accomplish by the means shown in the drawings and hereinafter specitically described.

That which I regard as new will be set forth in the claims.

In the accompanying drawings, Figure lis a vertical section through the valve, showing the position of the parts when the disks are firmly pressed against their seats. Fig. 2 is a similar view with the upper part of the device broken away and showing the position of the parts when the disks are released from their seats preparatory to being raised. Fig. 3 is a view similar to Fig. 2, with the disks raised to partlyl uncover 4the'passages that they control. Fig. t is a detail, beinga View of the inner face of one of the disks. Fig. 5 is a detail, being an elevation of the wedgingsleeve that is located between the two disks; and Fig. 6 is a partial vertical section through the wedging-sleeve and one of the disks, the other disk being in elevation.

Referring to said drawings, 6 indicates the main or body portion of the valve, having oppositely-located extensions 7, through which extend passages 8, screw-threaded, as usual, to receive the screwthreaded ends of pipesections.

9 indicates the neck portion, to which is screw-threaded the bonnet 10 and which in turn has screw-threaded to it at its upper end a stuffing-box nut 11. Around the contracted inner end of each passage 8 is formed a valveseat 12.

13 indicates two disks or valves each adapted to be seated on one of the valve-seats 12 to close the passages S. The rear or inner face of each disk 13 is provided with a large concave portion 14, at the lower end of which vis another and considerably smaller concave IOO . concaved portion 15.

18 indicates a notch formed in the lower edge of the lip 16 of each disk.

19 indicates a stop or tapered projection on the bottom of the chamber in the main or body portion and so loc-ated that when the disks are forced down, as hereinafter explained, it will project between them and act as a stop to limit their downward movement and also as a spreader to incline the disks, moving their lower edge portions outward against their respective seats. This stop or projection 1.9 is tapered just sufficiently so thatwhile serving to effectively stop the descent of the disks it inclines them at their lower edge portions laterally toward the seats and permits the seating of the valves by the wedging action between the sleeve and the disks, as hereinafter described, to be more easily accomplished. If this stop were not tapered, but had a fiat or squared end, then in the operation of setting the disks to their seats the friction of the disks on such stop would have to be overcome.

2O indicates the stein or rod, provided with an ordinary hand-wheel 2l at its upper end. This stem or rod passes through the stuffingboX cap 11 and bonnet 10. It is provided, as shown, with two oppositely-cut screw- threads 22 and 23, the scre`w-thread 22 being a righthand screwwhich engages with screw-threads formed in the bonnet 10 and the screw-thread 23 being a left-hand screw on the lower portion of such stem or rod.

21 indicates an interiorly-screw-th readed sleeve adapted to receive the lefthanded screw-threaded portion 23 of the stem or rod 20. This sleeve 24 is adapted to pass between the two disks 13 and rest within the large concaved portions 14 on the rear or inner faces of such disks. The lower end of this sleeve, on opposite sides thereof, is beveled downward, as indicated at 25, such beveled portions lying, when the parts are in position, opposite the oppositely-beveled portions 15"L on the rear or inner faces of the disks 13, so that a powerful wedging actionv directly on the shoulder of the groove.

the surface 25 bears upon the surface 15a at its highest point, which, as above stated, lies substantially central of the disk. At opposite sides of the sleeve and between the two curved and beveled portions 25 extend down; ward two arms 26, that have heads 27 formed on their lower ends, said heads being adapted, when the parts are in position, to extend into the grooves 17 and so engage the disks that as the valve is being opened the heads 27 will vcarry the disks along after the spreading strain has been relieved, which release of the spreading strain always precedes the engagement of the heads 27 with the disks.

In operation, with the parts in position as shown in Fig. 1, in order to open the valve the stern or rod is turned so as to cause it to rise, which will by its engagement with the sleeve 24 also cause said sleeve to be lifted. By reason of the engagement of the stem or rod with said sleeve being through screwthreads of opposite character to that which engages the screw-threads in the bonnet the raising of the disks will be accelerated, owing to the relative movement of the sleeve on its said screw-thread. By this construction important advantages are secured in that the disks are raised by fewer turns of .the stem or rod and a shorter stem or rod can be employed, both of which features are very desirable in certain instances'. The width of the grooves 17 vis greater than that of the heads 27 that rest ltherein, and owing to this fact it will be evident that a slight upward movement of the sleeve 24C will take place upon commencing theoperation of opening the valve before said heads contact with the upper This slight upward movement removes the force that holds the disks to their seats by causing the disengagement of the beveled faces 15L and 25, and when this is accomplished the parts will be substantially in the position indicated in Fig. 2, insuring the disks being drawn up practically out of pressure-contact with their seats, as indicated in Fig. 3, thus guarding them against danger of such scratches and defacing as would tend to promote leakage,

'especially when employed to control the iiow of iuids under high pressure. Upon turning the stem or rod 20 in the reverse direction to lower the disks the compound screw action is again brought into use, as described in referring to the reverse operation, and of course materially shortens the time in closing the valve. During the descent of the disks they will not be forced against their respective seats until such disks are in position to entirely cover the passages 8. At that time further downward movement of the disks will be prevented by the stop 19, which will spread the disks, inclining them and moving their lower edge portions into contact with their seats. By this means not only is the danger of movement of the disks across the faces of the seats during the subsequent spreading operation reduced, but the valve- IIO.

' ness of iit.

disks are also more strongly supported at the point where they are subjected to the greatest strain-'viz., at the bottom. Afterward the two oppositely-beveled portions 15L and 25 will come together and the wedgin g effects thus produced will cause the said disks to be forced tightly against their seats without rubbing and be there held. The disks are thus presented squarely tol their seats-1l. e., without movement upon or across the faces thereof-and pressed thereon without scraping or scratching, such as frequently occurs when the faces of the disks and their seats or either of them are inclined and one or the other, or both, moved edgewise to act as a wedge or Wedges to secure the desired tight- In my construction the two curved and beveled portions 15 and 25 bear against each other when brought together; but as the curvature of the two surfaces is dierent when the sleeve 24 is forced down the curved and beveled portion 25 on the sleeve is advanced slightly on the beveled portion 15a, and by reason of these two portions being differently curved, as shown and described, the contact in each case is substantially at the center of the disk and is more that of a point than a line, and hence the disks have a slight rocking motion that is of service in securing a better seating of the disks. Owing to the abruptness of the inclination of the beveled portions 15 and 25 when the valve is being closed, the disks Will be moved without being spread apart until they are stopped by the projection 19, the said beveled portions, however, being sufficient to spread the disks and force them against their respective seats with great force after the disks are so stopped. An angle of about forty-five degrees has been found by act-ual tests to accomplish both purposes. The angle, however, may be varied according to the size of the valve.

By this improved construction I close my valve perfectly tight by spreading the disks firmly against their seats after they have been stopped in the downward movement across the seats, and I open my valve by first relieving the spreading strain against the seats, and then moving the disks upwardly across the seats, thus avoidingthe tearing and scratching of the disks and seats, which so frequently is the case with all previous constructions when the valve is being opened and closed.

' So far as I am aware no one has heretofore produced a valve of similar character in which the disk or disks are spread laterally by the action of a spreader acting centrally upon them and arranged to permit rocking of the disks so that they may adjust themselves to their seats. Nor am I aware that any one has produced a valve in which the disk or disks are first tilted or inclined to move one edge portion thereof against their seats, the disks being afterward moved up tightly against their seats by pressure applied thereto at substantially the center. I wish it understood, therefore, that my invention is not restricted to the specific details of construction described and illustrated, except in so far as such details are specically claimed.

That which I claim as my invention, and desire to secure by Letters Patent, is-

l. In a gate-valve, the combination of a disk, a seat for the same, means for moving said disk without sliding under pressure on said seat, means for forcing said disk laterally against its seat by impingement substantially against the center thereof afterits movement across its seat has been stopped, and a Wedge-stop for such disk which acts to tilt and move a portion of the disk laterally against its seat before said forcing means operates, substantially as described.

2. In a gate-valve, the combination with a pair of disks, of means for applying pressure to said disks substantially centrally thereof for spreading said disks apart and seating them against their seats without sliding under pressure thereon, and means for tilting the disks to move a portion thereof laterally into contact with their seats before said spreading means operates, substantially as described.

3. A gate-valve having a disk, a seat therefor, means for moving said disk edgewise into and out of position opposite its seat, means for applying pressure to said disk substantially centrally thereof for forcing said disk laterally against its seat without further edgewise movement, and means for tilting said disk to move one edge portion thereof against its seat before the rest of the disk is forced thereagainst, substantially as described.

4. A gate-valve having a disk, a seat therefor, means for moving said disk into and out ot' position opposite its seat without sliding under pressure thereon, and means having a rocker-bearing on said disk for forcing it laterally tightly against its seat, substantially as described.

5. A gate-valve having a disk, a seat therefor, means for moving said disk into and out of position opposite its seat Without sliding under pressure thereon, means having a rockerbearing on said disk for forcing it laterally tightly against its seat, and auxiliary means acting to move an edge portion of said disk laterally against its seat before said'forcing means acts to force said disk on its seat, substantially as described.

6. A gate-valve having a disk, a seat therefor, means for moving said disk into and out of position opposite its seat, and means hav- IOO IIO

ing a substantially central rocker-bearing on of said disk and acting thereon before said forcing means operates to press the disk on its seat, substantially as described.

8. In a gate-valve, the combination with a pair of disks adapted to control the ilow of fluid through the valve, and each provided on its rear or inner face with a curved and beveled projecting portion, of a movable sleeve located between said disks and having a curved and beveled portion adapted to bear against and slide upon the said beveled portions on the disks, forming a rocker-bearing, means for connecting said disks and sleeve together, and means for moving said sleeve, substantially as and for the purpose specified.

9. In a gate-valve, the combinationv with a pair of disks adapted to control the ilow of liquid through the valve, of a movable sleeve located between said disks and adapted when said disks are brought opposite their respective seats to force said disks against said seats, projections carried by said sleeve and fitting within grooves in said disks, said grooves being wider than said projections, whereby said sleeve may have a slight upward movement independent of said disks, and means for moving said sleeve, substantially as and for the purpose specified.

10. A gate-valve consisting of a pair of oppositely-arranged parallel disks, seats therefor, means for moving said disks into and out of position opposite their seats without sliding under pressure thereon, and means having substantially central rocker-bearings on said disks for spreading said disks to force them against their seats, substantially as described.

ll. A gate-valve havinga disk, a seat therefor, means for moving said disk edgewise into and out of position opposite its seat, a sleeve connected with said moving means and having a central rocker inclined bearing on said disk for forcing it laterally tightly against its seat, and a stop limiting the downward movement of said disk and adapted'to move 45 lthe lower edge thereof toward its seat, substantially as described.

12. In a gate-valve, the combination with two disks adapted to be spread apart firmly against their seats without sliding thereon, of an operating stem or rod provided with a right and left hand screw-thread, a xed support for said-stem or rod with which one of said screw-threads engages, a sleeve between Vsaid disks in which the other of the screwthreads moves, and means carried by said f sleeve and engaging said disks forming center rocker-bearings for spreading said disks by longitudinal movement of said sleeve with reference thereto, substantially as described.

13. In a gate-valve, the combination with two disks adapted to be spread apart firmly against their seats without sliding thereon, of an operating stem or rod provided with a right and a left hand screw-thread, a fixed support for said stem or rod with which one of said screw-threads engages, a sleeve between said disks in which the other of the screw-threads moves, and means operated by the movement of said sleeve for spreading said disks, substantially as and for the purpose specified.

lll. Agate-valve havinga disk, a seat therefor, meansfor moving said disk into and out of position opposite its seat, means having a substantially central rocker-bearing on said disk for forcing said disk against its seat without edgewise movement while in pressure-contact therewith', and means for tilting said disk to move one edge portion thereof against its seat before said forcing means acts to press the rest of the disk thereagainst, substantially as described.

ALFRED M. HEWLETT.

Witnesses:

J. C. BANNIsTnn, H. L. DAY.

Images