US 3319926 A
Description (OCR text may contain errors)
y 1967 H. w. BOGER 3,319,926
MULTIPLE SIGNAL ACTUATED DIAPHRAGM VALVE Filed Dec. 17, 1965 HENRY W. BOGER l N VEN TOR.
United States Patent Ofilice 3,319,926 MULTIPLE SIGNAL ACTUATED DIAPHRAGM VALVE Henry William Boger, Westwood, Mass., assignor to Worthington Corporation, Harrison, NJ, a corporation of Delaware Filed Dec. 17, 1%5, Ser. No. 514,559 Claims. (Cl. 251-61) This invention relates generally to diaphragm valves, and more particularly to a diaphragm valve capable of being actuated by separate signals in isolated chambers.
In many pressure fluid systems, e.g. cryogenic systems, it is desirable to completely enclose the valve actuating mechanism in order to prevent leakage which normally occurs about the valve stem. These systems utilize diaphragm valves which are actuated from within by external pressure signals.
Diaphragm valves may consist of a diaphragm acting against a valve seat to interrupt or control the flow of fluid in a flow passage. In the prior art, these diaphragms were actuated either by a single signal pressure which forced the diaphragm against the seat or, in the case of normally closed valves, a single signal pressure which unseated the diaphragm and opened the flow passage.
In some fluid pressure control systems, this type of prior art valve has proved inadequate. For example, in control systems operated by different fluid pressures, in which it is necessary to compare one control pressure with another, before making a correction in the controlled fluid. In such systems, it is often desirable when making the correction to proportion it to the difference between control pressures. This type of control is frequently encountered in proportional servomechanisms.
The prior art diaphragm valves can not perform these desirable control functions because they are limited to single signal inputs.
The present invention is capable of performing these desirable control functions. It provides multiple signal input chambers, isolated from one another and from the controlled fluid flow passage. These chambers are capable of receiving independent control signals and actuating the valve by moving the diaphragm in response to these independent signals or in response to the differential pressure across the diaphragm caused by the dnlerences in these signals.
Accordingly, it is an object of this invention to provide a diaphragm valve with multiple signal input chambers, so that the valve may be actuated by separate signal inputs.
It is another object of this invention to provide a multiple signal input diaphragm valve wherein the signal input chambers are isolated from one another and from the controlled fluid flow passage.
It is a further object of this invention to provide 21 diaphragm valve for use as a multiple signal input proportional controller.
These and other objects and advantages of the invention will become evident from the following description with reference to the accompanying drawings in which:
FIGURE 1 is a side elevation of the valve in cross section;
FIGURE 2 is a side elevation in partial cut-away and cross section taken along the line 2-2 of FIGURE 3; and
FIGURE 3 is a top view in partial cut-away of the valve in FIGURE 1.
Referring to the drawings, FIGURE 1 shows the valve body, designated generally as 1. The valve is made in two partsa cover 2, and a base 3-which are fastened together in any convenient manner, as by bolts 4, to form a cavity 5. This cavity is divided into an upper portion 6 and a lower portion 7 by the single flexible diaphragm 3,319,926 Patented May 16, 1957 8, which may be made of any appropriate material, e.g. rubber or Teflon, and which is clamped firmly between the cover and the base thereby isolating the upper portion from the lower portion. The lower portion is further divided into two isolated chambers by means of the clamp ring 9 disposed above the diaphragm 8 (See FIGURE 3), and firmly clamped to the annular boss it of the base 3, as by bolts 11.
The chambers thus formed in the lower portion 7 of the valve body, for convenience will be referred to hereinafter as the second signal input chamber 12, and the fluid flow chamber 13; while the chamber formed in the upper portion 6 will be referred to as the first signal input chamber.
A diaphragm actuating plate 15 is mounted above the diaphragm t5, and, in the preferred embodiment of this invention, is acted upon by the spring 16 to seat the diaphragm against the raised seating surface 17 in the base 3 of the valve body.
This raised seating surface 17 is at the end of the inlet flow passage 18 in the base 3 of the valve body. The base also contains an outlet flow passage 19 communicating with the fluid flow chamber 13, and a second signal input passage 25', FIGURE 2, communicating with the second signal input chamber 12.
The cover 2 contains a first signal input passage 21, FIGURE 2, which communicates with the first signal input chamber 6.
The aforementioned passages are all adapted to be connected in any appropriate fashion to suitable conduit means for transmission of pressure'signals and pressure fluid.
Operation In operation, the fluid to be controlled by this valve will normally be prevented from flowing through the inlet flow passage 18 into the fluid flow chamber 13, because the valve is normally biased closed by the spring 16. See FIGURE 1.
An external fluid pressure signal input supplied thru passage 29 to the second signal input chamber 12 (FIG URE 2), of sufficient magnitude to overcome the force of the spring, will cause the valve to open, and fluid will flow from the inlet flow passage into the fluid flow chamber 13 and thence out the outlet flow passage 19. Under these conditions, the first signal input chamber may simply be vented to the atmosphere through the first signal input passage, or, for cryogenic service, the first signal input chamber may be purged with a dry gas to prevent frost from forming inside.
An alternate mode of operation is to have this valve operate as a reverse acting fluid controller in a servomechanism. For example, if it is used as part of a temperature control mechanism, the valve could control the flow of fuel or coolant in response to a differential pressure signal input caused by having the second input passage connected to the output of a temperature measuring device and the first signal input passage connected to the input of the same temperature measuring device. This invention is thus ideally suited for such service, being equipped with separate signal chambers, isolated not only from each other, but also from the controlled fluid flow passage.
in this device, control over fluid fiow is proportional to the signal input and can be made proportional to differential signal input. Thus, for a particular application, a safety signal might be provided to the first signal input chamber to further bias the valve closed. Under such a condition, the normal input signal in the second signal input chamber would fail to open the valve, until either the safety signal were removed or the difference in pressure between the safety signal and the input signal to the second signal input chamber, became such that the pressure below the diaphragm was greater than that above it.
It will be understood that various changes in the details, materials and arrangements of parts which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention, as expressed in the appended claims.
What is claimed is:
1. A fluid pressure actuated valve comprising:
(a) a body having a cavity therein;
(b) a flexible member fixedly mounted in said cavity and dividing said cavity into a first signal chamber, a second signal chamber and a fluid flow chamber;
(c) means in said cavity coacting with said flexible member and said body to isolate the chambers from one another;
(d) said body having a fluid flow inlet passage therein communicating with the fluid flow chamber and terminating in a valve seat within said fluid flow chamber;
(e) said body having a discharge passage therein communicating with said fluid flow chamber;
(f) said body having a first signal passage communicating with said first signal chamber, and a second signal passage communicating with said second signal chamber, for receiving separate pressure fluid signals; and
(g) an actuating means movably mounted in said first signal chamber and coacting with said member to operate said valve by moving the flexible member against the valve seat, and permitting the flexible member to move away from the valve seat in response to pressure signals in the second signal chamber and in the fluid flow chamber which are in excess of the pressure exerted against the diaphragm in the first signal chamber.
2. A valve as in claim 1 wherein: said body comprises, an upper portion and a lower portion, said lower portion having an annular boss formed thereon within said cavity; said flexible member comprises a diaphragm which is fixedly clamped by and between said upper and lower portions thereby sealing said portions from one another; and an annular ring is disposed in said upper portion and fixedly clamped to the boss in said lower portion thereby clamping said diaphragm therebetween and sealing that part of the lower portion which is within the annular boss from that part which is without the annular boss, whereby said first signal chamber is formed above said diaphragm in said upperportion, said second signal chamber is formed below said diaphragm without said annular boss, and said fluid flow chamber is formed below said diaphragm within said annular boss.
3. A valve as in claim 2 wherein said actuating means comprises a rigid plate disposed in said upper portion above, and in contact with, said diaphragm, and a spring mounted in said upper portion above and in contact with said plate to exert a force against said plate, whereby the plate will normally hold the diaphragm against the valve seat in the flow chamber thereby maintaining the valve in normally closed position in the absence of a sufficient pressure signal in either the second chamber or the fluid flow chamber to offset the force of the spring.
4. A valve in claim 3 wherein a portion of the plate is disposed above the fluid flow chamber, said portion being the portion acted upon by the spring and another portion of the plate is disposed above the second signal chamber to be acted upon by pressure signals in said second signal chamber transmitted through said diaphragm whereby said valve may be opened by a suflicient pressure signal in said second signal chamber to overcome the force of the spring and any pressure signal supplied to said first signal chamber through said first signal passage.
5. A fluid pressure actuated valve for fluid control comprising:
(a) a valve body having an inlet and an outlet;
(b) a first annular boss on said body;
(c) a second annular boss on said body disposed concentric to said first annular boss, said first annular boss, being within said second annular boss;
((1) a diaphragm disposed on said first and second annular bosses;
(e) means fixedly connected to said diaphragm and said first and second annular bosses to form thereby an isolated chamber between said bosses and an isolated chamber within said first annular boss;
(f) a signal passage in said body communicating with the isolated chamber formed between said annular bosses for receiving external pressure fluid signals;
(g) passage means in said valve body communicating said inlet and said outlet with the isolated chamber formed within said first annular boss;
(h) means mounted on said valve body to move said diaphragm to control the flow of fluid between the inlet and outlet passage means in the isolated chamber formed within said first annular boss, such that said valve is normally closed; and
(i) means connected to said last mentioned means and connected to, and coacting with, said diaphragm to actuate said last mentioned means to open said valve in response to external pressure fluid signals transmitted thru said signal passage to the isolated chamber formed between said annular bosses.
References Cited by the Examiner UNITED STATES PATENTS 2,187,768 1/1940 Arquint et al. 25161 X 2,207,840 7/1940 Tornquist 25161 X 2,677,390 5/1954 Davies et a1 25 l6l X References Cited by the Applicant UNITED STATES PATENTS 2,529,028 11/1950 Landon. 2,989,282 6/1951 White. 3,100,002 8/1963 Moore. 3,138,168 6/1964 Waller.
M. CARY NELSON, Primary Examiner.
A. ROSENTHAL, Assistant Examiner.