GB2215815A - Fluid control valve - Google Patents
Fluid control valve Download PDFInfo
- Publication number
- GB2215815A GB2215815A GB8807292A GB8807292A GB2215815A GB 2215815 A GB2215815 A GB 2215815A GB 8807292 A GB8807292 A GB 8807292A GB 8807292 A GB8807292 A GB 8807292A GB 2215815 A GB2215815 A GB 2215815A
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- GB
- United Kingdom
- Prior art keywords
- spool
- valve
- ports
- sleeve
- adjacent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
- F16K11/00—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves
- F16K11/02—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit
- F16K11/06—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit comprising only sliding valves, i.e. sliding closure elements
- F16K11/065—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit comprising only sliding valves, i.e. sliding closure elements with linearly sliding closure members
- F16K11/07—Multiple-way valves, e.g. mixing valves; Pipe fittings incorporating such valves with all movable sealing faces moving as one unit comprising only sliding valves, i.e. sliding closure elements with linearly sliding closure members with cylindrical slides
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- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Multiple-Way Valves (AREA)
Abstract
A fluid control valve has a spool 10 mounted within a cylindrical sleeve 12, and a plurality of ports distributed along the longitudinal axis of the spool, there being a constituent sleeve portion 12A, 12B both between each adjacent pair of ports, and in which each valve port is formed. There is an adjacent pair of ports, such as a service port 22b and a return port 24b, arranged such that when the service port is shut off by a spool land 23 there is a spool chamber 29 extending from the land to the return port, at the same fluid pressure as in the return port, and there is relatively high fluid pressure in the shut off service port. O-ring seals 16 are provided between the sleeve and the valve body 15 and different fluid pressures, at different points along the sleeve, compress the seals. In order to reduce the tendency of the sleeve to flex, the sleeve portion extending between the return and service ports is provided with a reduced thickness part 30 contiguous with the service port, and an O-ring may be provided between the reduced thickness sleeve part and the valve body; and/or an O-ring extends in a plane including the control edge of the spool land when closing the service port. <IMAGE>
Description
FLUID CONTROL VALVE
THIS INVENTION relates to a fluid control valve, and, in particular, to such a valve having spool mounted within a cylindrical sleeve, the sleeve being clamped in a cylindrically shaped aperture in a body, and the sleeve providing ports for the valve, O-ring seals being provided between the sleeve and the body, and the O-ring seals being distributed along the longitudinal axis of the spool.
Usually there is a plurality of ports distributed, in the sleeve, along the longitudinal axis of the spool, there being constituent cylindrical portions of the sleeve having the valve ports therein, and other such sleeve portions between each adjacent pair of valve ports.
Further, references in this specification, and the accompanying claims, to a port, include references to a sole port, or an arrangement of a plurality of identical, separate, constituent, ports, distributed about the circumference of the cylindrical chamber in which the valve spool is displaceable, and comprising, in effect, a single port. Thus, any single port, along the longitudinal axis of the spool, may comprise either a sole port, or a plurality of constituent ports distributed about the circumference of the cylindrical chamber in which the valve spool is displaceable, irrespective of whether each co-operating single port is a sole port, or a plurality of constituent ports.However, the sole, or any constituent port, of, say, a return port, may not be in the same plane, including the longitudinal axis of the spool of the valve, as the sole, or any constituent, port, of, say, a co-operating inlet port.
Because of the provision of the ports in. the sleeve, and especially when, at least some of, the il.et, return and service ports each comprise a plurality of constituent ports distributed about the circumference of the cylindrical chamber in which the valve spool is displaceable, the sleeve has a tendency to flex.
In the operation of the valve, different fluid pressures are present at different positions along the longitudinal axis of the spool, causing different O-ring seals to be compressed between the sleeve and the body by different amounts. Usually the arrangement is such that each constituent portion of the sleeve between each adjacent pair of valve ports, along the longitudinal axis of the spool, is provided with at least one O-ring seal, to enable the sleeve portion to be clamped to the valve body. Thus, different fluid pressures act on different O-ring seals, possibly, causing the sleeve to. flex.
Differences of fluid pressure occur, along the longitudinal axis of the spool, when at least one port is shut off, because of different fluid pressures established at different ports, for example, a service port and a return port. Inevitably, there is leakage of the fluid to the return port. Thus, in the operation of the valve, with a service port closed, typically, the fluid pressure at the service port is half the fluid pressure at the inlet port of the valve, it being considered that the fluid pressure at the return port is zero.
Such a difference in fluid pressure along the longitudinal axis of the spool increases to a maximum value a few seconds after the valve has closed. The portion of the sleeve between the service port and the return port extends longitudinally along a chamber formed between a reduced diameter portion of the spool, and the sleeve. The spool chamber extends between two lands provided by the spool. When one land shuts off the service port, and the return port is not shut off, the fluid pressure established at the spool chamber is the same fluid pressure as the substantially zero pressure established at the return port.
Thus, for a known valve construction, and in the operation of the valve, the portion of the sleeve between the return port and the service port is subjected to substantially zero pressure.
If the sleeve flexes, then the spool-o-sleeve clearance at, at least, one position along the longitudinal axis of the spool, may be other than is desired. For example, the clearance may be less than is desired, causing the frictional forces acting on the spool to be greater than is desired, and in an extreme case, the spool may be rendered immovable.
It is an object of the present invention to provide a novel and advantageous construction for a fluid control valve having a spool mounted within a cylindrical sleeve, the sleeve being clamped in a body with O-ring seals provided therebetween, the O-ring seals being distributed along the longitudinal axis of the spool, in operation, there being differences of fluid pressure along the longitudinal axis of the spool, the novel construction of the valve being such that the tendency of the sleeve to flex, because of such differences of fluid pressure, is reduced.
According to the present invention a fluid control valve having a spool mounted within a cylindrical sleeve, and a plurality of ports distributed along the longitudinal axis of the spool, the sleeve being clamped in a cylindrically shaped aperture in a body, with O-ring seals provided therebetween, the
O-ring seals being distributed along the longitudinal axis of the spool, there being constituent cylindrical portions of the sleeve having the valve ports formed therein, and other such sleeve portions between each adjacent pair of valve ports, and each such constitutent portion of the sleeve between an adjacent pair of valve ports being provided with at least one O-ring seal, in the operation of the valve, fluid pressure within the valve acting to compress the O-ring seals, and there being at least one pair of adjacent ports arranged such that, with one of the ports shut off by a spool land, there is a difference between the fluid pressures established within the pair of adjacent ports, one sleeve portion extends, between said one pair of adjacent portS, along a spool chamber, and a first fluid pressure is established both in the spool chamber, and in said other port, said one port being formed in an adjacent sleeve portion, a second fluid pressure is established in said one port, the second fluid pressure being greater than the first fluid pressure, and possibly said first fluid pressure being substantially zero, and the control edge of the spool land has a part of the spool land adjacent thereto, when the spool land closes said one port, said part of the spool land is spaced from a reduced thickness part of said one sleeve portion extending between the pair of ports, the reduced thickness part of said one sleeve portion being contiguous with said one port.
Thus, the reduced thickness part of said one sleeve portion is subjected to the second fluid pressure established in said one port, the remainder of said one sleeve portion being subjected to the first fluid pressure established in the spool chamber. Hence, said two adjacent sleeve portions associated with said pair of ports are less likely to flex because of different fluid pressures along the longitudinal axis of the spool, and established at the two ports, than with known constructions of such a valve.
Inevitably, the spool land is larger than in a valve of a conventional construction.
The, or one of the, O-ring seals, provided to clamp said one sleeve portion to the valve body, may be provided between the reduced thickness part of said one sleeve portion, and the valve body.
The O-ring seal provided between the reduced thickness part of said one sleeve portion, and the valve body, may extend, at least substantially, in a plane at right angles to the longitudinal axis of the spool, and also including -the control edge of the spool land when closing said one port.
If the O-ring seal associated with the reduced thickness part of said one sleeve portion lies, at least substantially, in the plane including the control edge of the spool land when closing said one port, the spool-to-sleeve clearances on either side of said one port, and along the longitudinal axis of the spool, are substantially the same.
According to another aspect of the present invention a fluid control valve has a spool mounted within a cylindrical sleeve, and a plurality of ports distributed along the longitudinal axis of the spool, the sleeve being clamped in a cylindrically shaped aperture in a body, with O-ring seals provided therebetween, the O-ring seals being distributed along the longitudinal axis of the spool, there being constituent cylindrical portions of the sleeve having the valve ports formed therein, and other such sleeve portions between each adjacent pair of valve ports, and each such constitutent portion of the sleeve between an adjacent pair of valve ports being provided with at least one O-ring seal, in the operation of the valve, fluid pressure within the valve acting to compress the O-ring seals, and there being at least one pair of adjacent ports arranged such that, with one of the ports shut off by a spool land, there is a difference between the fluid pressures established within the pair of adjacent ports, one sleeve portion extends, between said one pair of adjacent ports, along a spool chamber, and a first fluid pressure is established both in the spool chamber, and in said other port, said one port being formed in an adjacent sleeve portion, a second fluid pressure is established in said one port, the second fluid pressure being greater than the first fluid pressure, and possibly said first fluid pressure being substantially zero, and the, or one of the, O-ring seals, provided to clamp said one sleeve portion to the valve body, extends at least substantially, in a plane at right angles to the longitudinal axis of the spool, and also including the control edge of the spool land when closing said one port.
The present invention will now be described by way of example, with reference to the accompanying drawings, in which:
Figure 1 is a sectional side elevation of a known form of a hydraulic control valve with a spool mounted within a cylindrical sleeve, the sleeve being clamped in a cylindrically shaped aperture in a body, with O-ring seals provided therebetween, and
Figure 2 corresponds to Figure 1, but shows a modification in accordance with the present invention, comprising the provision of reduced thickness parts of the sleeve contiguous with each service port of the valve, the modification ensuring that the sleeve has a reduced tendency to flex, in relation to the known valve construction of Figure 1, because of different fluid pressures along the longitudinal axis of the spool, and established at the service port and a co-operating return port.
Figure 1 shows a hydraulic control spool valve, having a spool 10, displaceable along its longitudinal axis, and a co-operating sleeve 12. The sleeve 12 is mounted within a cylindrical aperture 14 of a body 15, annular O-ring seals 16 being provided at spaced locations along the longitudinal axis of the valve. The sleeve 12 defines a cylindrical chamber 17 in which the spool 10 is displaceable.
Hydraulic fluid enters the valve through a centrally located port 20a in the body 15, and through a co-operating port 20b in the sleeve 12. When the valve is open the fluid flows to one of two service ports 22a, and 22a', in the body 15, over the appropriate land 23 in the spool 10; and via a co-operating service port 22b, or 22b', in the sleeve 12. The fluid flows from the other service port 22b', or 22b, respectively, to the associated one 24a', or 24a, of two return ports, in the body, via a co-operating return port 24b', or 24b, in the sleeve.
Each of the valve ports comprises a plurality of separate, identical, constituent, ports, distributed about the circumference of the cylindrical chamber 17 in which the spool 10 is displaceable, and comprising, in effect, a single port.
Usually, any constituent port of the service port 22b, or 22b', is not in the same plane, including the longitudinal axis of the spool 10, as any constituent port of the co-operating return port, respectively, 24b, or 9'+b'.
Figure 1 is of an imaginary plane, including the longitudinal axis of the spool 10, for convenience, constituent ports of all inlet the return and service ports, being shown in this plane.
The spool 10 is shown in a position in which the spool lands 23 close the service ports 22b, and 22b', in the sleeve 12. The ends of the spool comprise lands 26, b c the lands 26 do not close the return ports 24b, and 24b', when the service ports 22b and 22b' are closed. Between the two intermediate spool lands 23 is a reduced diameter portion 27 of the spool, the chamber 28 provided by this reduced-diameter portion 27 of the spool being normally in communication with the inlet port 20b in the sleeve 12.
Between adjacent pairs of ports, for example, between each return port 24b, or 24b', and the adjacent service port 22b, or 22b', is a cylindrical sleeve portion 12A; and each port is formed in a cylindrical sleeve portion 12B. One, or two,
O-ring seals 16 are provided for each of the sleeve portions 12A.
Thus, there are two arrangements each of an adjacent, co-operating pair of ports, comprising a service port 22b, or 22b', and a return port 24b, or 24b', and an associated pair of sleeve portions 12A, and 12B, along the longitudinal axis of the spool. For either such arrangement, when the service port 22b, or 22b', is shut off by a spool land 23, there is substantially zero fluid pressure established both at the return port 24b, or 24b', and at a spool chamber 29, corresponding to the spool chamber 28; and extending between the co-operating pair of ports. With the service port closed, the spool chamber 29 is in communication with the return port, the return port being only partially shut off by the spool land 26. Further, there is a relatively high fluid pressure established at the shut off service port 22b, or 22b'.Inevitably, there is leakage of the fluid from the service port to the return port, and, typically, the fluid pressure at the closed service port is half the fluid pressure at the inlet port 20b. Thus, the sleeve portion 12A is subjected to zero fluid pressure, and the sleeve portion 12B is subjected to a higher fluid pressure. The O-ring seals 16 are compressed by the fluid pressure to which the associated sleeve portion 12A is subjected.
Because of such pressure differences along the longitudinal axis of the spool, the thin sleeve 12, having the plurality of ports, each comprising a plurality of constituent ports, formed therein, has a tendency to flex, causing the spool-to-sleeve clearance to vary along the longitudinal axis of the spool. Thus, at certain positions along the spool the clearance may be, for example, less than is desired, causing the frictional forces acting on the spool to be greater than is desired, and in an extreme case, the spool may be rendered immovable.
The modification of the hydraulic control spool valve of Figure 1, shown in Figure 2, is such that the tendency for the sleeve to flex is reduced.
Parts of the control valve of Figure 2 identical to, or closely resembling, parts of the valve of Figure 1 are identified by the same reference numerals in both Figures.
The modification, in accordance with the present invention, at least includes providing a reduced thickness part 30 for each sleeve portion 12A, the reduced thickness part being contiguous with the adjacent service port 22b, or 22b'. The reduced thickness part 30 of the sleeve portion 12A is spaced from the part of the spool land 23 adjacent to a control edge 34 of the spool land, when the spool land closes the service port.
Thus, when either of the service ports 22b, or 22b', is shut off by a spool land 23, the major portion of the sleeve portion 12A, between the service port and the co-operating return port, is subjected to substantially zero fluid pressure; but the reduced thickness part 30 of the sleeve portion 12A is subjected to the relatively high fluid pressure established at the service port. Hence, the tendency of the sleeve 12 to flex adjacent to the service port is reduced.
Inevitably, because of the provision of the reduced thickness part 30 of the sleeve portion 12A, the spool land 23 is larger than in the known construction for a valve shown in
Figure 1.
The reduced thickness part 30 of the sleeve portion 12A; as shown, is provided by a channel-shaped groove formed in the sleeve. Alternatively, the reduced thickness part 30 may be provided by chamfering the sleeve.
The, or one of the two, O-ring seals 16 provided for the sleeve portion 12A is shown located between the reduced thickness part 30 and the valve body 15. This feature is desirable but not essential. In addition, this O-ring seal 16 is shown extending, at least substantially, in a plane, indicated partially by a dotted line 36, and including the control edge 34 of the spool land 23. This feature also is desirable, but not essential.
If this O-ring seal 16 is provided between the reduced thickness part 30 and the valve body 15, and lies substantially in the plane 36 including the control edge 34 of the spool land 23, when the spool land closes the service port, the spool-to-sleeve clearance on either side of the service port, and along the longitudinal axis of the spool, is substantially the same.
According to another aspect of the present invention, and irrespective of whether, or not, there is provided a reduced thickness part of the sleeve portion contiguous with the service port, the, or one of the two, O-ring seals 16, provided for the sleeve portion between the co-operating service, and return, ports, is arranged to extend, at least substantially, in a plane at right angles to the longitudinal axis of the spool, and also including the control edge of the spool land when closing the service port.
A modification in accordance with the present invention, and as described above, can be made in relation to any appropriate pair of ports of a control valve, different fluid pressures being likely to be established at the two ports. Possibly the appropriate pair of ports comprise an inlet port, and either a service, or a return, port.
Claims (7)
1. A fluid control valve having a spool mounted within a cylindrical sleeve, and a plurality of ports distributed along the longitudinal axis of the spool, the sleeve being clamped in a cylindrically shaped aperture in a body, with O-ring seals provided therebetween, the O-ring seals being distributed along the longitudinal axis of the spool, there being constituent cylindrical portions of the sleeve having the valve ports formed therein, and other such sleeve portions between each adjacent pair of valve ports, and each such constituent portion of the sleeve between an adjacent pair of valve ports being provided with at least one O-ring seal, in the operation of the valve, fluid pressure within the valve acting to compress the O-ring seals, and there being at least one pair of adjacent ports arranged such that, with one of the ports shut off by a spool land, there is a difference between the fluid pressures established within the pair of adjacent ports, one sleeve portion extends, between said one pair of adjacent ports, along a spool chamber, and a first fluid pressure is established both in the spool chamber, and in said other port, said one port being formed in an adjacent sleeve portion, a second fluid pressure is established in said one port, the second fluid pressure being greater than the first fluid pressure, and the control edge of the spool land has a part of the spool land adjacent thereto, when the spool land closes said one port, said part of the spool land is spaced from a rPaced thickness part of said one sleeve portion extending between the pair of ports, the reduced thickness part of said one sleeve portion being contiguous with said one port.
2. A valve as claimed in claim 1, in which the, or one of the, O-ring seals, provided to clamp said one sleeve portion to the valve body, is provided, between the reduced thickness part of said one sleeve portion, and the valve body.
3. A valve as claimed in claim 2, in which the O-ring seal provided between the reduced thickness part of said one sleeve portion, and the valve body, extends, at least substantially, in a plane at right angles to the longitudinal axis of the spool, and also including the control edge of the spool land when closing said one port.
4. A valve as claimed in any one of the preceding claims, in which the reduced thickness part of said one sleeve portion is provided by a channel-shaped groove formed in the sleeve.
5. A valve as claimed in any one of claims 1 to 3, in which the reduced thickness part of said one sleeve portion is provided by chamfering of the sleeve.
6. A fluid control valve having a spool mounted within a cylindrical sleeve, and a plurality of ports distributed along the longitudinal axis of the spool, the sleeve being clamped in a cylindrically shaped aperture in a body, with O-ring seals provided therebetween, the O-ring seals being distributed along the longitudinal axis of the spool, there being constituent cylindrical portions of the sleeve having the valve ports formed therein, and other such sleeve portions between each adjacent pair of valve ports, and each such constituent portion of the sleeve between an adjacent pair of valve ports being provided with at least one O-ring seal, in the operation of the valve, fluid pressure within the valve acting to compress the O-ring seals, and there being at least one pair of adjacent ports arranged such that, with one of the ports shut off by a spool land, there is a difference between the fluid pressures established within the pair of adjacent ports, one sleeve portion extends, between said one pair of adjacent ports, along a spool chamber, and a first fluid pressure is established both in the spool chamber, and in said other port, said one port being formed in an adjacent sleeve portion, a second fluid pressure is established in said one port, the second fluid pressure being greater than the first fluid pressure, and the, or one of the, O-ring seals, provided to clamp said one sleeve portion to the valve body, extends, at least substantially, in a plane at right angles to the longitudinal axis of the spool, and also including the control edge of the spool land when closing said one port.
7. A fluid control valve substantially as described herein, with reference to Figure 2 of the accompanying drawings.
7. A -fluid control valve substantially as described herein, with reference to Figure 2 of the accompanying drawings.
Amendments to the claims have been filed as follows
Claims 1. A fluid control valve has a spool mounted within a cylindrical sleeve, and a plurality of ports distributed along the longitudinal axis of the spool, the sleeve is clamped in a cylindrically shaped aperture in a body, at least one spool chamber is provided within the spool, and each spool chamber is between an adjacent pair of lands provided by the spool, there are constituent first cylindrical portions of the sleeve with the valve ports formed therein, and second cylindrical sleeve portions between each adjacent pair of valve ports, a plurality of O-ring seals are provided between the sleeve and the body, and the O-ring seals also are distributed along the longitudinal axis of the spool, each of the second cylindrical portions of the sleeve, between an adjacent pair of valve ports, is associated with at least one O-ring seal, in the operation of the valve, fluid pressures within the valve act to compress the
O-ring seals, and the arrangement in relation to at least one pair of adjacent ports is such that, a spool land provides an edge to control the flow of fluid from one of the pair of adjacent ports, and with the spool land closing said one of the pair of adjacent ports, a spool chamber extends from the spool land to communicate with the other of the pair of adjacent ports, a second cylindrical sleeve portion extends between the pair of adjacent ports, and said one port is formed in a first cylindrical sleeve portion adjacent to said second cylindrical sleeve portion, a first fluid pressure is established within both said other of the pair of adjacent ports, and the spool chamber, and acts on said second cylindrical sleeve portion, a second fluid pressure, greater than the first fluid pressure, is established in said one port, and a part of the spool land, adjacent to the control edge provided by the spool land, is spaced from, and is opposite to, a reduced thickness part of said second cylindrical sleeve portion, and the reduced thickness part of said second cylindrical sleeve portion is contiguous with said one port, so that said second fluid pressure acts on the reduced thickness part of said second cylindrical sleeve portion.
2. A valve as claimed in claim 1, in which at least one of the O-ring seals is provided between the reduced thickness part of said second cylindrical sleeve portion, and the valve body.
3. A valve as claimed in claim 2, in which the, or one of the, O-ring seals provided between the reduced thickness part of said second cylindrical sleeve portion, and the valve body, extends, at least substantially, in a plane at right angles to the longitudinal axis of the spool, and the plane also includes the control edge of the spool land when closing said one port.
4. A valve as claimed in any one of the preceding claims, in which the reduced thickness part of said second cylindrical sleeve portion is provided by a channel-shaped groove formed in the sleeve.
5. A valve as claimed in any one of claims 1 to 3, in which the reduced thickness part of said second cylindrical sleeve portion is provided by chamfering of the sleeve.
6. A fluid control valve has a spool mounted within a cylindrical sleeve, and a plurality of ports distributed along the longitudinal axis of the spool, the sleeve is clamped in a cylindrically shaped aperture in a body, at least one spool chamber is provided within the spool, and each spool chamber is between an adjacent pair of lands provided by the spool, there are constituent first cylindrical portions of the sleeve with the valve ports formed therein, and second cylindrical sleeve portions between each adjacent pair of valve ports, a plurality of O-ring seals are provided between the sleeve and the body, and the O-ring seals also are distributed along the longitudinal axis of the spool, each of the second cylindrical portions of the sleeve, between an adjacent pair of valve ports, is associated with at least one O-ring seal, in the operation of the valve, fluid pressures within the valve act to compress the
O-ring seals, and the arrangement in relation to at least one pair of adjacent ports is such that, a spool land provides an edge to control the flow of fluid from one of the pair of adjacent ports, and with the spool land closing said one of the pair of adjacent ports, a spool chamber extends from the spool land to communicate with the other of the pair of adjacent ports, a second cylindrical sleeve portion extends between the pair of adjacent ports, and said one port is formed in a first cylindrical sleeve portion adjacent to said second cylindrical sleeve portion, a first fluid pressure is established within both said other of the pair of adjacent ports, and the spool chamber, and acts on said second cylindrical sleeve portion, a second fluid pressure, greater than the first fluid pressure, is established in said one port, and the control edge of the spool land is in a plane at right angles to the longitudinal axis of the spool, and the plane also includes an 0being seal provided between said second cylindrical sleeve portion and the valve body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8807292A GB2215815A (en) | 1988-03-26 | 1988-03-26 | Fluid control valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8807292A GB2215815A (en) | 1988-03-26 | 1988-03-26 | Fluid control valve |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8807292D0 GB8807292D0 (en) | 1988-04-27 |
| GB2215815A true GB2215815A (en) | 1989-09-27 |
Family
ID=10634205
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8807292A Withdrawn GB2215815A (en) | 1988-03-26 | 1988-03-26 | Fluid control valve |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2215815A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2240609A (en) * | 1990-02-02 | 1991-08-07 | Ferranti Int Plc | Fluid control valve |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB820797A (en) * | 1955-02-21 | 1959-09-23 | Bendix Aviat Corp | Improvements in or relating to fluid valves |
| GB1021500A (en) * | 1963-10-28 | 1966-03-02 | Westinghouse Air Brake Co | Fluid-flow control spool valves |
| US3590874A (en) * | 1969-11-21 | 1971-07-06 | David Y Rice Co | Valve design |
| US3680596A (en) * | 1970-12-28 | 1972-08-01 | Ross Operating Valve Co | Resilient seal spool valve |
| US3680593A (en) * | 1969-12-31 | 1972-08-01 | Systems Design Co Inc | Valve |
| GB1324369A (en) * | 1969-12-18 | 1973-07-25 | Dowty Seals Ltd | Fluid flow control valves and sealing devices therefor |
| GB1524891A (en) * | 1975-01-17 | 1978-09-13 | France Armed Forces | Breathing apparatus |
-
1988
- 1988-03-26 GB GB8807292A patent/GB2215815A/en not_active Withdrawn
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB820797A (en) * | 1955-02-21 | 1959-09-23 | Bendix Aviat Corp | Improvements in or relating to fluid valves |
| GB1021500A (en) * | 1963-10-28 | 1966-03-02 | Westinghouse Air Brake Co | Fluid-flow control spool valves |
| US3590874A (en) * | 1969-11-21 | 1971-07-06 | David Y Rice Co | Valve design |
| GB1324369A (en) * | 1969-12-18 | 1973-07-25 | Dowty Seals Ltd | Fluid flow control valves and sealing devices therefor |
| US3680593A (en) * | 1969-12-31 | 1972-08-01 | Systems Design Co Inc | Valve |
| US3680596A (en) * | 1970-12-28 | 1972-08-01 | Ross Operating Valve Co | Resilient seal spool valve |
| GB1524891A (en) * | 1975-01-17 | 1978-09-13 | France Armed Forces | Breathing apparatus |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2240609A (en) * | 1990-02-02 | 1991-08-07 | Ferranti Int Plc | Fluid control valve |
| US5123450A (en) * | 1990-02-02 | 1992-06-23 | Ferranti International Plc | Fluid control valve |
| GB2240609B (en) * | 1990-02-02 | 1993-11-24 | Ferranti Int Plc | Fluid control valve |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8807292D0 (en) | 1988-04-27 |
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