Slit Diaphragm Valve

Abstract

A slit diaphragm valve having a slit diaphragm and a control plate retained in facial contact. The slit diaphragm is a circular sheet of rubber having a centrally positioned elongated slit. The control plate is a flat perforated circular metal plate with a centrally positioned control opening. Fluid flow in one direction is unrestricted whereas flow in the other direction is restricted by the size of the control opening in the control plate. Another embodiment includes a pair of control plates for controlled flow in both directions. Still another embodiment functions as a check valve by employing a perforated control plate having no central opening.

Description

STATEMENT OF GOVERNMENT INTEREST

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a valve and more particularly to a slit diaphragm valve for controlling fluid flow in one or both directions.

2. Description of the Prior Art

Previously available valves for controlling fluid in one or both directions have included breather valves, relief valves, check valves and recirculation control devices, for example. These valves often include relatively complex mechanical systems such as hinged covers, sliding pistons and other mechanical levers and parts. In addition, these valves are expensive, require maintenance and are subject to frequent failure.

These disadvantages are overcome by the present invention by the use of a very simple and reliable valve that employs a flexible slit diaphragm and has no moving metal parts.

SUMMARY OF THE INVENTION

Briefly, the present invention comprises a slit diaphragm valve having a slit diaphragm and a control plate retained in facial contact. The slit diaphragm is a circular sheet of rubber having a centrally positioned elongated slit. The control plate is a flat perforated circular metal plate with a centrally positioned control opening. Fluid flow in one direction is unrestricted whereas flow in the other direction is restricted by the size of the control opening in the control plate. Another embodiment includes a pair of control plates for controlled flow in both directions. Still another embodiment functions as a check valve by employing a perforated control plate having no contral opening.

STATEMENT OF THE OBJECTS OF THE INVENTION

An object of the present invention is to provide a valve that is inexpensive and reliable.

Another object is to provide a valve that has control of fluid flow in one or both directions.

Still another object is to provide a valve wherein the moving element is made of elastomeric material.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a pictorial view of one embodiment of the slit diaphragm valve of the present invention;

FIG. 2 is an exploded view of the slit diaphragm valve of FIG. 1;

FIGS. 3A, 3B and 3C are diagrams illustrating the operation of the slit diaphragm valve of FIGS. 1 and 2;

FIG. 4 is an exploded view of another embodiment of the valve of the present invention in which the flow is variable in both directions;

FIG. 5 is an exploded view of another embodiment of the valve of the present invention in which the valve functions as a check valve;

FIG. 6 is another embodiment of the slit diaphragm that may be used in the different embodiments of the slit diaphragm valves of the present invention;

FIG. 7 is still another embodiment of the slit diaphragm that may be used in the different embodiments of the slit diaphragm valves of the present invention; and

FIG. 8 is still another embodiment of the slit diaphragm that may be used in the different embodiment of the slit diaphragm valves of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 is illustrated a pictorial view and in FIG. 2 is illustrated an exploded view of one embodiment of the slit diaphragm valve 11 of the present invention. Slit diaphragm valve 11 includes flanges 13 and 15, slit diaphragm 17 and control plate 19. The piping 21 of a system, in which the slit diaphragm valve 11 may be used, is illustrated by broken lines in FIG. 1. The piping may be connected to the flanges by means of bolts, welding or the like. Flanges 13 and 15 normally have inside diameters d.sub.1 and d.sub.2 that are about the same as the inside diameter of the piping to which they are connected. However, these openings may be larger or smaller depending upon special design considerations. Flanges 13 and 15, respectively, include openings 23 and 25 through which bolts 27 of FIG. 1 may be inserted. Slit diaphragm 17 is made of an elastomeric material, preferably neoprene, and includes openings 29 through which bolts 27 of FIG. 1 may be inserted. Slit diaphragm 17 also includes a slit 31 that is preferably straight, is center positioned and has a length L.sub.1. The length L.sub.1 is preferably the same as, or longer than, the inside diameter d.sub.1 of flange 13. This is because if L.sub.1 is lesser than d.sub.1, the slit has a tendency of tearing at the ends after a certain duration use. However, if this limited use is a permissible condition, then L.sub.1 may be made of lesser length and will provide a more restricted flow than if L.sub.1 were the same as or greater than diameter d.sub.1. Control plate 19 includes a center opening 33 having a diameter d.sub.3, a plurality of openings or perforations 35, and openings 37 through which bolts 27 of FIG. 1 may be inserted. Depending upon the desired flow control the diameter d.sub.3 may be varied. Openings 35 are made throughout the exposed region of control plate 19 and provide for relatively unrestricted and uniform flow when fluid flow is in the uncontrolled or upward direction. The size and spacing of openings 35 are based upon providing adequate flow and strength. If high strength is not essential, then a greater total area of openings 35 is preferred. In certain situations, depending upon the size of the opening 35, it may be desirable that openings not be provided directly behind the slit of slit diaphragm 17. That is, adjacent to slit 31 should be provided a solid backing except where opening 33 is provided. This will provide a somewhat better seal and control of flow in the downward direction and control will be determined only by opening 33. When assembled, flanges 11 and 15, slit diaphragm 17 and control plate 19 lie flat against each other and are clamped in place by bolts 27 to provide structural integrity and an effective seal at the periphery of the valve.

In FIGS. 3A, 3B and 3C is shown the schematic sequential operation of the slit diaphragm valve 11 of the present invention. The elements of the valve are shown in spaced relation for illustrative purposes. Above each figure is illustrated the configuration of the slit for that particular condition.

FIG. 3A illustrates the components of the valve when there is no flow in either direction through the valve. From this diagram it can be seen that slit 31 of slit diaphragm 17 is closed and provides a tight seal in both directions.

FIG. 3B illustrates the components of the valve when there is fluid flow through the valve in the upward or unrestricted direction. From this figure it can be seen that slit 31 has separated to provide a relatively large opening 31B. It can also be seen that there is a free flow of fluid through openings 33 and 35 of control plate 19. Therefore, when the flow is in the upward direction, control plate 19 does not control or restrict the fluid flow.

FIG. 3C illustrates the components of the valve when there is fluid flow in the downward or restricted direction. From this figure it can be seen that slit 31 has separated to provide a relatively small opening 31C. This is because control plate 19 prevents all parts of slit 31 from separating except that part of slit 31 that is adjacent opening 33. Therefore, only restricted flow is allowed to pass through openings 31C and 33 in the downward direction.

From this it can be seen that a variable flow valve of FIGS. 1 and 2 is provided that is simple and very effective. This valve may be used in many applications where variable flow in opposite directions is desired. That is, it may be used in piping systems as either a breather valve, relief valve or a circulation control device, for example.

In FIG. 4 is illustrated another embodiment of the present invention. This embodiment differs from the previously described embodiment in that it includes a pair of control plates 41 and 43 positioned on opposite sides of slit diaphragm 17. Control plate 41 includes an opening 45 that has a diameter d.sub.4. Control plate 43 has an opening 47 that has a diameter d.sub.5. From this it can be seen that flow in the upward direction is controlled by the diameter d.sub.4 of opening 45 and flow in the downward direction is controlled by the diameter d.sub.5 of opening 47. As illustrated in FIG. 4, opening 45, having a diameter d.sub.4, is larger than opening 45, having a diameter d.sub.5. Therefore, flow in the upward direction is less restricted than flow in the downward direction. It should be particularly noted that the simplicity of removing and then inserting different control plates having different sized openings is one of the unique features of the present invention.

In FIG. 5 is illustrated another embodiment of the present invention. This embodiment differs from the previously described two way flow valves in that it allows flow in only one direction, that is, it functions as a check valve. This embodiment includes a pair of control plates 49 and 51. It should be particularly noted that control plate 49 has no central opening and therefore prevents slit 31 from opening when there is a pressure differential that would otherwise cause fluid flow in the upward direction. Control plate 51 has an opening 53, having a diameter d.sub.6, which controls the flow in the downward direction in the same manner as described in the previous embodiments. The perforated openings 35 in control plate 49 allow flow in the downward direction but are spaced and sized in such a manner as to prevent slit 31 from opening for what would otherwise be flow in the upward direction. It should be noted that control plate 51 need not include perforations 35. Moreover, the valve in this embodiment would still function as a check valve if control plate 51 were removed.

In FIG. 6 is illustrated another embodiment of the slit diaphragm 17 that may be used in the previously described embodiments of the slit diaphragm valve of the present invention. This slit diaphragm includes a plurality of magnets 55 that are imbedded in each side of the elastomeric material. This may be used when a more positive closure is required. Also, springs may be used in place of the magnets, or in conjunction with them, to provide a more positive closure.

In FIG. 7 is illustrated still another embodiment of the slit diaphragm 17 that may be used in the previously described embodiment of the slit diaphragm valve of the present invention. This slit diaphragm includes a plurality of slits 57 in the elastomeric material. These plurality of slits allow a larger flow than the previously described single slit.

FIG. 8 illustrates still another embodiment of the slit diaphragm 17 that may be used in the previously described embodiment of the slit diaphragm valve of the present invention. This slit diaphragm includes a plurality of short and or long parallel or nonparallel unconnected slits 59 in the elastomeric material. This plurality of slits allows a larger flow due to a larger cross sectional area of elastomeric material which can be used.

Claims

1. A valve comprising:

a. a flat diaphragm made of elastomeric material and having at least one slit formed therein;

b. a flat first control plate having a center opening positioned in the center region thereof;

c. means holding one side of said flat diaphragm in facial contact with one side of said flat first control plate;

d. said flat first control plate has a plurality of fluid transfer openings formed therein that surround said center opening;

e. said slit is elongated, is centrally positioned and has a predetermined length that is greater than the diameter of said center opening; and

f. whereby said flat first control plate restricts said slit from opening

2. The valve of claim 1, wherein:

a. the diameters of said plurality of openings are substantially smaller

3. The valve of claim 1, including:

a. a flat second control plate having a center opening positioned in the center region thereof;

b. means holding the other side of said flat diaphragm in facial contact with one side of said second flat control plate; and

c. said predetermined length of said slit is equal to or greater than the diameter of the opening in said second control plate and the diameter of the opening in said second control plate is greater than the diameter of

4. The valve of claim 3 wherein:

a. said second control plate has a plurality of openings formed therein that surround said center opening; and

b. the diameters of said plurality of openings are substantially smaller

5. The valve of claim 1 including:

a. a flat plate having a plurality of openings formed therein;

b. the diameters of said plurality of openings are substantially smaller than the diameter of said center opening in said first control plate; and

6. The valve of claim 1 wherein:

a. said flat diaphragm has a plurality of magnets embedded adjacent said

7. The valve of claim 1 wherein:

a. said flat diaphragm has a plurality of slits formed therein.