US991230A - Overbalanced fluid-pressure valve. - Google Patents

Description

B. P. NOYBS.

OVERBALANGED FLUID PRESSURE VALVE.

APPLICATION FILED JULY 8, 1910.

Patented May 2, 1911.

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UNITED s'rATEs PATENT OFFICE.

EDWARD r. NOYES, -or WINCHESTER, MASSACHUSETTS, assreu'on r0 0 r- POWER COMPANY, or NEWARK, NEW JERSEY, A CORPORATION OF NEW JERSEY.

OVERBALANCED FLUID-PRESSURE VALVE.

Specification of Letters Patent.

Patented May 2, 1911.

Original application filed February 26, 1919, Serial No. 546,133. Divided and this application filed July 8, 1910. Serial No. 570,974.

To all whom 'it may concern:

Be itknown that I, EDWARD P. NoYEs, a citizen of the United States, residing at VVipchester, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Overbalanced Fluid-Pressure Valves, of which the following is a specification.

This invention relates to valves adapted.

to be actuated mechanically and also by the pressure of the fluid controlled by the valve, and its object is to provide a valve which is predisposed by the pressures. acting thereon when at or near closure to go to or remain on its seat, but possessing such capability of control of the acting pressures as to enable the valve when desired to be unseated with the exertion of a moderate mechanical force. The valve may further have provision for bringing into play an additional fluid force in the regions of wider opening, which force may be of such moment as to overcome the normal tendency toward closure and thus hold the valve open.

This application-is' divided from my co pending application Serial No. 546,133, filed February 26,1910.

Of the accompanying drawings, Figure 1 represents a vertical sectional view of a. valve device constructed according to my as an inlet or anterior chamber, and an outlet or posterior chamber 3, the two being connected by a port 4 surrounded by a valve-seat 5 with which the single-seating main valve 6 cooperates. This valve is formed upon a moving piece or member 7 which also has a motor piston 8W0rking in a cylinder 9 of the valve casing, and furthermore this piece has a telescopic connection with a hearing or guidelO which depends from the detachable cover 11 of the cylinder. Thereby are formed two chambers 12, 13 on the upper or valve-closing side of the member 7, the former being an annular intermediate-pressure or controlling chamber surrounding the telescopic connection, and the latter chamber 13 being abalancing chamber, so-called because when opened to the pressure in the posterior chamber 3 a substantial part oft-he area of the main valve 6 is balanced as to posterior pressure.

The intermediate chamber 12 has a restricted inlet from anterior chamber 2 by way of a small aperture 14formed in the piston 8 (or through any other suitable opening'such as that which may be formed by making the piston 8 a loose fit in its cylinder in the well-known manner), and it has an outlet to the balancing chamber 13 by way of a duct 15 formed in the cylinder cover' and a port 16 controlled by the tapered pllot valve 17 and the superjacent close-fitting piston portion 18 formed on an operating stem 19, the latter having suit able operating connections such as thee- levers 20, 21 and the connecting linkage as shown.

An outlet from balancing chamber 13 to the posterior chamber 3 -is;provided by way of a port 22 formed in an extension stem piece 28 of the member 7 having its bearing in a guide 24, and thisoutlet is controlled by a pilot valve 25 formed on the lower end of stem 19. Said stem also has a boss or shoulder 26 adapted to abut against acomplemental shoulder 27 formed on the memher 7, there being some lost motion. in order that the initial upward movement of stem 19 shall merely open the pilot valve .25, while further upward movement causes the main valve to be positively lifted from its seat.

The dotted extension lines aa represent the diameter of the bearing 10 of the telescopic connection, or the smaller diameter .of chamber 12, the lines b-J) represent the The diameter b-b being greater than 1 aa, it follows that the effective or projected area of member 7 exposed to the downward or valve-closing pressure in chamber 12 exceeds that of said member exposed to the upward or valve-opening pressure in chamber 2 by an area a-b. This area 1 term an over-balancing annulus for the reason that when pressures are equalized in the anterior and intermediate chambers 2, 12 on the one hand, and the posterior and balancing chambers 3,13 on the other hand, the main valve will be held to its seat by fluid pressure, the annulus a'b being exposed in a downward direction to the pressure in chamber 12 and in an upward di-.

. relation to the diameter of the main valve port 4 (so long of course as it is not made so large as to -obliterate the chamber 13) thus affording any desired measure of closing pressure-force, regardless of the size of the main valve.

In operation, assuming the main and pilot' valves to be. closed as shown, the anterior pressure will accumulate in thechambers 12 and13 by leakage past the sliding surfaces or other leakage inlets thereto, and thus the main valve will be held to its seat by this pressure actingover the whole of the upper surface of member 7, opposed only by the anterior pressure acting on the under side of piston 8, since the posterior pressure 111 chamber 3 will supposedly have fallen away. Then to open the main valve the stem 19 will be raised so as to open pilotvalve 25, and this will blow down the pressure in the balancing chamber 13 to that of the posterior chamber 3. The main valve still tends to remain on its seat, but with a greatly lessened pressure since all the areas have been balanced except that of annulus (Z -b, and this force can be readily overcome by a further upward movement of stem 19 which through the shoulders '26, 27 causes the main valve to be mechanically lifted from its seat.

If the opening of the main valve increases the posterior pressure, as of course will generally be the case, the net downward or closing pressure on annulus ab decreasesin consequence, and this decrease continues as the posterior pressure continues to rise.

The first part of the upward movement of stem 19 leaves the piston portion 18 there- 'of in the port 16, and hence the. pressure in chamber 12 remains the same as the an terior pressure, but at a certain point in the rise of stem 19 the tapered valve 17 begins to open and partly drop the pressure in chamber 12', in consequence of which the downwardly-acting forces may .soon become smaller than the upwardly-acting forces, causing the main'valve-to be automatically opened wider, its tendency to go to an extreme opening however, being retarded or arrested by the reaction of the rising posterior ressure which tends to check the drop oi pressure in 12. W hen-once the preponderance of upward pressure has been es tablished by a suitable opening of pilotvalve 17, the main valve, without further mechanical assistance from stem 19, tends to gradually attain a wider opening until the balance of acting forces has been restored, and the amount of this opcning'may be made to depend upon the amount of opening of the valve 17.

The amountof lost motion between stem 19 and member 7, as well as the degree of taper of valve 17 and other features of design atlecting the construction 'or operation may of course be suitably arranged as. desired. v

To produce a closure of the main valve, the stem 19 is depressed, thus at first constricting and finally closing port 16, so that pressure accumulates in chamber 12 (checked in its rapidity howe'ver by the falling posterior pressure so long as port 16 is open) and forces the shoulder 27 against shoulder 26, so that the main valve may be seated by fluid pressure under the mechanical restraint of stem 19. During such closing movement, the overbalancing activity of annulus abcomes again into play with increasing eifeet. Vhen the. main valve is seated, a further downward movement of stem 19 seals the port 22 and all flow to the posterior chamber 3 will then be stopped.

Fig. 2 represents a construction in which the piston annulus bo of Fig. 1 is omitted together with the cylinder in which piston 8 works and thepilot valve controlling the outlet from chamber 12 above said piston. In other words the additional motor force which is brought into play by controlling the pressure above said piston is absent in Fig. 2.. The device then becomes simply. an overbalancedsingle-seating valve provided with the balancing chamber 13, whereby the valve-seating pressure which accumulates when the valve is closed may be relieved over a greater or less area of the main valve, and provided with the pilot stem having a loose mechanical connection with the main valve. This type possesses the advantage over exactly-balanced or under-balanced valves, that it is held to its seat by fluid ressure even when the pressure is relieved in the balancing chamber (although it may be opened against said seating pressure with moderate inltial and decreasing final effort) it is more adaptable to use in other than vertical positions, and itsclosure is placed more fully under the control of the stem 19, because if the overbalancing annulus a--?) is relatively large enough to overcome the static forces such as friction (and gravity when the valve is inverted) the valve will close without being pushed by the stem and having the fluid-pressureconditions upset by the pilot-valve closure which such pushing entails.

The structural embodiment is of course subjectto considerable variation without departure from my invention.

I claim,

1. In valve apparatus, the combination of a casing and a member with single-seating main valve, together forming a balancing chamber provided with an outlet tothe posterior side of the valve, whereby pressure which accumulates in said chamber when its outlet is closed may be relieved to permit the opening of the' valve without having to overcome the anterior pressure over its whole area, said member having an overbalancing area whereby it is held seated when the pressure in said chamber is relieved, and operating means provided with a pilot valve which controls said outlet and having a lost-motion connection with the main valve whereby the latter may be opened by a continuation of the outlet-opening movement of said means.

2. In valve apparatus, the combination of.

a casing having anterior and posterior chambers connected by a port, a movable member telescoping with the casing and having a main valve which controls the connection between said chambers and closes in the direction of flow, said member forming with the casing a balancing chamber having an outlet to the posterior chamber through said member and an inlet wherethrough it receives pressure fluid from the anterior chamber, the effective valve-closing area of said member exposed in said balancing'chamber being less than the effective area of the main valve exposed to posterior pressure, and an operating stem having a lost-motion connection with said member for opening the main valve when the stem is moved relatively thereto in one direction and provided with a pilot valve which closes saidoutlet when the stem is relatively moved direction.

3. In fluid-pressure valve apparatus, the

area of the valve, said chamber providedwith an outlet to the posterior side of the valve and adapted to accumulate the pressure anterior to. the valve when said outlet is closed, and a controlling chamber having an inlet for the anterior pressure and an outlet, one of which is adjustable'in' size, and means for controlling the outlet of the balancing chamber and for mechanically controlling said main-valve member.

4. In valve apparatus, the combination of a casing having anterior and posterior chambers connected by a port, a movable member telescopically connected with said casing and forming therewith an intermediate chamber surrounding the telescopic connection and in shunt between the anterior and posterior in the opposite lieving the pressures on said valve-closing chambers, said member having a main valve controllin' said port and a motor piston interposedetween the anterior and intermediate chambers, the etfective area of the piston adjacent to the intermediate chamber, being greater than the eflective-area of said member adjacent to the anterior chamber, and means for controlling the relation between the inflow to and the outflow from said intermediate chamber. v

5. Valve apparatus comprising a casing having anterior and posterior chambers connected by a port, a movable member telescopically connected with said casing and forming therewith an intermediate chamber surroundingthe telescopic connection and having a restricted inlet from the anterior chamber, and a balancing chamber having an inlet from the intermediate chamber'and an outlet to the posterior chamber, said member provided with a main valve controlling said port and a motor piston interposed between the anterior and intermediate chambers, the effective area of the piston exposed to intermediate pressure being greater than the effective area of said member exposedv to anterior pressure, and two pilot valves controlling respectively the inlet to and the outlet from said balancing chamber.

6. Valve-apparatus comprising a valvecasing having anterior and posterior chambers connected by a port, a movable member having a main valve controlling said port, a valve-opening area, a valve-closing area opposed-thereto and a second valve-closing area less than the posterior area of the main valve, and an operating stem having a lostmotion connection with said member for positively opening the main valve, and having also serially-acting pilot valves for reareas.

7. Valve-apparatus comprising a. casing having anterior and posterior chambers conhas an effective valve-closing area smaller I than the effective posterior area of the valve, said balancing chamber provided with an inlet from the intermediate chamber, and an outlet to the posterior chamber through the web of the movable member, and a stem adapted to positively open the main valve and carrying a pilot valve which controls the inlet from the intermediate to the balancing chamber and also carrying a second pilot valve adapted to seat on the web of the movable member and seal the outlet from the balancing chamber to the posterior chamber. a

' 8. Valve-apparatus comprising a casing having anterior and posterior chambers connected by a port, and a guide member, a movable member telescoping with said guide member and forming with the casing an intermediate chamber having an inlet from the anterior chamber, and a balancing chamber having an inlet from the intermediate chamber through a passage within said guide member, said movable member provided with a main valve controlling said port, a web located between the balancing chamber and the posterior chamber and formed with 'a port connecting the two, and

a motor piston interposed between the anterior and intermediate chambers and having an effective area exposed to the latter, greater than the effective area of the movable member exposed to anterior pressure, and a pilot stem having a loose mechanical connection with said movable member for positively opening the main valve and formed with a valve controlling said pas sage within the guide,. an adjacent piston portion adapted to enter and close said assage, and a second pilot valve adapte to close the port in said web.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses, this thirtieth day of June, 1910.

EDWARD P. NOYES Wit-nesses:.

R. M. PIERSON, ARTHUR H. BROWN.

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