IL104717A - In-line fluid control valve - Google Patents

Description

10A7_17/2 IN LINE FLUID CONTROL VALVE inn n1?^ ELHANAN TAVOR C: 16436 FIELD OF THE INVENTION The present invention relates to control valves generally and more particularly to in-line fluid control valves.

BACKGROUND OF THE INVENTION A great variety of control valves are known for various applications. A particularly efficient in-line control valve is described in U.S. Patent 4,681,130 of the present inventor. Relevant prior art is listed in the References Cited therein.

SUMMARY OF THE INVENTION The present invention seeks to provide an improved and greatly simplified in-line control valve.

According to the present invention, there is provided an in-line valve, comprising: a housing having an inlet at one end to be coupled coaxially to an upstream fluid line, an outlet at the opposite end to be coupled coaxially to a downstream fluid line, and an annular valve seat between said inlet and outlet and coaxial therewith; a cylindrical sleeve mounted coaxially within said housing and radially spaced therefrom to define an annular flow passageway around the sleeve, said sleeve being open at its upstream end and closed at its downstream end; a cylindrical piston assembly having an upstream end closed by an upstream end wall circumscribed by an annular seal, and an open downstream end facing said closed downstream end of the sleeve and defining a control chamber therewith, said piston assembly being axially movable within said cylindrical sleeve either to a closed position wherein said annular seal engages said annular valve seat, or to an open position wherein said annular seal is spaced from said annular valve seat to permit flow via said annular flow passageway to said outlet; a control passageway leading into said control chamber and selectively controllable for applying a control pressure to said control chamber tending to move the piston assembly to the closed position in opposition to the inlet pressure tending to move the piston assembly to the open position; the effective cross-sectional area of said control chamber being substantially equal to that subtended by said annular seal such that when said control pressure applied to the control chamber is equal to the inlet pressure, the force applied by the inlet pressure to move the piston assemby to its open position is substantially equal to and balanced by the force applied by the pressure in the control chamber to move the piston assembly to its closed position; and a spring disposed within the control chamber for biassing the piston assemby to one of said positions .

In one described embodiment, the spring is a compression spring and biasses the piston assembly to a normally-closed position; and in a second described embodiment, the spring is a tension spring and biasses the piston assembly to a normally-open position.

According to further features in the described preferred embodiment, the cylindrical sleeve is fixedly mounted within the housing by a plurality of vanes, and the control passageway is formed through one of the vanes. In one described embodiment, the vanes extend radially with respect to the cylindrical sleeve; and in a second described embodiment, the vanes extend tangentially with respect to the cylindrical sleeve.

According to further features in the described preferred embodiments, the annular valve seat is defined by a conical section of the housing inlet. In addition, the end wall closing the upstream end of the cylindrical piston assembly is of conical configuration decreasing in diameter towards the housing inlet. Further, the downstream end of the cylindrical sleeve is closed by a wall also of conical configuration, decreasing in diameter towards the housing outlet. In such a construction, the valve exhibits generally identical fluid flow parameters to fluid flow from the inlet to the outlet, or from the outlet to the inlet.

According to still further features in the described preferred embodiment, the housing includes a cylindrical side wall element mounting the cylindrical sleeve, an inlet coupling formed with the inlet, an outlet coupling formed with the outlet, and a pair of threaded flange elements threadedly securing the inlet and outlet couplings to the opposite ends of the cylindrical side wall element. Such features permit a compact valve construction.

It is appreciated that some or all of the foregoing features may be combined in any suitable combination in a given product .

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawing in which: Figs. 1A and IB are partially cut-away pictorial illustrations of a valve constructed and operative in accordance with a preferred embodiment of the present invention in respective open and closed orientations; Fig. 2 is a sectional illustration taken along the lines II - II in Fig. 1A and Fig. 3 is a sectional illustration of an alternative embodiment of the invention which illustration corresponds to Fig. 2.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Reference is now made to Figs. 1A, IB and 2, which illustrate an in-line valve constructed and operative in accordance with a preferred embodiment of the present invention. The valve comprises a housing, generally indicated by reference numeral 10, typically comprising a cylindrical side wall element 12 and identical line coupling elements 14 and 16 which are removably joined in sealing engagement with respective ends of element 12 by a pair of threaded flange elements 18. ^u ling, elements 14 and 16 couple the valve to a fluid line extending generally along a longit.udinal axis 17, which is the generally the axis of symmetry of the entire valve.

In accordance with a preferred embodiment of the present invention, integrally formed with cylindrical side wall element 12 and preferably molded or extruded together therewith is an internal sleeve 20 of generally cylindrical configuration which is joined to the cylindrical side wall element 12 by means of a plurality of vanes 22, which are also preferably molded or extruded together with element 12 and sleeve 20 as one piece.

In the illustrated embodiment of Figs. 1A, IB and 2, the vanes 22 extend generally radially between element 12 and sleeve 20. In an alternative embodiment shown in Fig. 3, vanes 24 extend tangentially to a sleeve 26 and join sleeve 26 to an outer wall portion 28. This arrangement provides enhanced ease and accuracy in injection molding of the unitarily formed wall member portion 28, vanes 24 and sleeve 26.

In the embodiment of Figs. 1A, IB and 2, a valve control fluid port 30 formed in housing 10 communicates via a passageway 32 formed in one of vanes 22 with the interior of sleeve 20. In the embodiment of Fig. 3, similarly a valve control fluid port 40 formed in wall 28 communicates via a passageway 42 formed in one of vanes 24 with the interior of sleeve 26.

Returning to Figs. 1A and IB, it is seen that mounted in fluid sealed engagement with sleeve 20 is an end portion 50 which has a generally smoothed conical configuration centered on longitudinal axis 17 and facing one end of a fluid line. The interior of end portion 50 includes a recess 52 which defines a spring seat for a spring 54.

Disposed in cylindrical sleeve 20 and arranged for axial movement relative thereto along axis 17 is a piston assembly 60. Piston 60 includes a generally cylindrical side wall portion 62 having a generally conical end portion 64 integrally formed therewith. A generally conical cover member 66 is mounted onto the generally conical end portion 64 over a generally truncated conical sealing element 67 having an upstanding ring portion 68 which is arranged to sealingly engage a corresponding valve seat region 69 of coupling element 14 when the piston assembly 60 is fully extended in a closed orientation, as seen in Fig. IB.

In the illustrated embodiment, cover member 66 and sealing element 67 are retained against conical end portion 64 by threaded engagement of a spring seat element 70 with a corresponding socket 72 formed in cover member 66.

Spring 54 is preferably a compression spring which tends to urge the piston assembly 60 into a normally closed orientation as illustrated in Fig. 1B.

The valve described above is operated by supplying a control fluid, which may be a gas or a liquid, under an appropriate pressure, which may be more or less than atmosphereic pressure, via port 30 and passageway 32 into the interior of piston assembly 60. Depending on the relationship of the pressure of the control fluid relative to the pressure outside of the piston assembly 60 interior of the housing, the control fluid pressure will either cause extension or retraction of the piston Jo as desired.

It is a particular feature of the present invention that the valve may be used for fluids traveling in either direction through housing 10, as /indicated by arrows 80 and 82. This is made possible by the fact thay the flow characteristics of the piston assembly 60 are generally the same as seen by fluids flowing in either of directions 80 and 82.

It is a further particular feature of the present invention that the cross sectional area subtended by the valve seat area 69 is generally equal to the cross sectional area of the interior of sleeve 20, and that the operation of piston assembly 60 is substantially not affected by fluid pressures impinging on regions other than cover member 66 and the interior of sleeve 20. It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. Rather the scope of the present invention is defined only by the claims which follow: PA 104717/3

Claims (9)

1. An in-line valve, comprising: a housing having an inlet at one end to be coupled coaxially to an upstream fluid line, an outlet at the opposite end to be coupled coaxially to a downstream fluid line, and an annular valve seat between said inlet and outlet and coaxial therewith; a cylindrical sleeve mounted coaxially within said housing and radially spaced therefrom to define an annular flow passageway around the sleeve, said sleeve being open at its upstream end and closed at its downstream end; a cylindrical piston assembly having an upstream end closed by an upstream end wall circumscribed by an annular seal, and an open downstream end facing said closed downstream end of the sleeve and defining a control chamber therewith, said piston assembly being axially movable within said cylindrical sleeve either to a closed position wherein said annular seal engages said annular valve seat, or to an open position wherein said annular seal is spaced from said annular valve seat to permit flow via said annular flow passageway to said outlet; a control passageway leading into said control chamber and selectively controllable for applying a control pressure to said control chamber tending to move the piston assembly to the closed position in opposition to the inlet pressure tending to move the piston assembly to the open position; the effective cross-sectional area of said control chamber being substantially equal to that subtended by said PA 104717/3 annular seal such that when said control pressure applied to the control chamber is equal to the inlet pressure, the force applied by the inlet pressure to move the piston assemby to its open position is substantially equal to and balanced by the force applied by the pressure in the control chamber to move the piston assembly to its closed position; and a spring disposed within the control chamber for biassing the piston assemby to one of said positions.

2. The valve according to Claim 1 , wherein said spring is a compression spring and biasses said piston assembly to a normally-closed position.

3. The valve according to either of Claims 1 or 2, wherein said cylindrical sleeve is fixedly mounted within said housing by a plurality of vanes, and said control passageway is formed through one of said vanes.

4. The valve according to Claim 3, wherein said vanes extend radially with respect to said cylindrical sleeve.

5. The valve according to Claim 3 , wherein said vanes extend tangentially with respect to said cylindrical sleeve.

6. The valve according to any one of Claims 1-5, wherein said annular valve seat is defined by a conical section of the housing inlet.

7. The valve according to any one of Claims 1-5, wherein said end wall closing the upstream end of the cylindrical piston assembly is of conical configuration decreasing in diameter towards said housing inlet. PA

8. The valve according to any one of Claims 1-7, wherein the downstream end of the cylindrical sleeve is closed by a wall of conical configuration decreasing in diameter towards said housing outlet .

9. The valve according to any one of Claims 1-8, wherein said housing inlet includes a cylindrical side wall element mounting said cylindrical sleeve, an inlet coupling formed with said inlet, an outlet coupling formed with said outlet, and a pair of threaded flange elements threadedly securing said inlet and outlet couplings to the opposite ends of said cylindrical side wall element. For the Applicant: P.O. Box 2273 Rehovot 76122 c.16436