GB2258908A - Improvements in and relating to fluid flow control valves - Google Patents

Abstract

A control valve for mixing hot and cold water has a housing 2 with inlets 7, 8 for hot and cold water, and an outlet 10 for mixed water. The housing accommodates a first plate 23 of T shape which is movable in directions 32 to control the proportions of hot and cold water in the mixed water, and a second plate in directions 26 to control the volume of mixed water. In a second embodiment (Fig. 2), slots 18, 19 in the second plate are omitted, and in a third embodiment, the first plate (49, Fig 3) is mounted on a carrier (52) for movement therewith in directions (58) to control the volume of mixed water and for movement relative thereto in directions (57) to control the temperature of the mixed water. Where it is required to only control the temperature of the mixed water, the second plate or the carrier may be omitted. <IMAGE>

Description

Improvements in and relating to Fluid Flow control Valves.

This invention relates to control valves for fluid flows and especially to those that provide control both over the total rate of flow of the fluids and over the proportioning of the rates of flows of the individual fluids.

The invention is particularly applicable, although not exclusively, to mixer valves in which incoming fluids are mixed and which provide control over the total rate of flow of the mixed fluids leaving the mixer and over the proportions of the fluids contained in the mixed output. Such mixer valves are used in domestic shower installations and they have controls that enable a user to control both the total flow of water leaving the mixer valve and the temperature of that water by regulating the proportion of hot water to that of cold water in the mixed flow leaving the mixer valve.

Examples of such mixing valves are described in European Patent Application No. 0384674. The required control over the total flow and over the proportional flows is provided by one or more movable plates with rectangular apertures in them.

The effective cross-sectional area and position of the apertures relative to hot and cold water inlets also of rectangular shape are variable by a user to set the mixer valve to provide an output of a required flow rate at a required temperature.

It is an object of the present invention to provide an improved form of control valve that has movable control plates of a design that is simpler and cheaper to manufacture that the plates described in European Patent Application No, 0384674.

According to the present invention a control valve for fluid flows comprises a housing with first and second fluid inlets and means for controlling the flow of fluids through the inlets, the means comprising a control plate located within the housing adjacent the inlets, the plate being of substantially Tshape and being movable within the housing in opposite directions both lying along the arms of the T in a manner and to an extent such that movement of the plate in one direction closes one inlet and opens the other whilst movement in the opposite direction opens the one inlet and closes the other.

Means are provided for moving the plate, such means being operable from outside the housing.

In one embodiment of the invention, the distance between the parallel sides of the stem of the T is equal to the distance between the centres of the inlets.

Preferably, the plate is so located in the housing that the stem of the T is symmetrically positioned with respect to the inlets when the fluid flows through the two inlets are equal. Thus, the inlets are opened and closed to the same extent on movement of the plate.

The plate may also be movable in opposite directions both of which lie along the stem of the T. Such movement opens and closes both inlets and the change is preferably the same for both inlets.

Preferably, the plate is associated with a second plate of generally rectangular form when seen in plan. The second plate is also located within the housing in abutting relationship with the first-mentioned plate and is movable relatively thereto in opposite directions both lying along the stem of the T. Movement of the second plate in one direction closes both inlets to the same extent whilst movement in the opposite direction opens both inlets to the same extent.

The second plate may have two spaced, parallel slots each of which is centred on one of the inlets.

Means operable from outside the housing are provided for moving the second plate.

By way of example only embodiments of the invention will now be described in greater detail with reference to the accompanying drawings of which: Fig. 1 is a diagrammatic view in exploded form of a first embodiment, Fig. 2 is a diagrammatic perspective view of components of a second embodiment, and, Fig. 3 is a diagrammatic perspective view of a component of a third embodiment.

The embodiment shown in Fig. 1 has a housing 1 of twopart form comprising a hollow body part 2 and an end closure plate 3. The body part 2 has two tubular extensions 4, 5 depending from a floor 6. The extensions 4, 5 form inlets for fluids to be mixed and they both open into the floor 6 in equisized,circular inlet orifices 7, 8 respectively. Above the floor 6, the body part 2 is contoured to form a fluids mixing chamber 9 of a generally pyramidal shape. Mixed fluids exit from the chamber 9 via a tubular outlet 10 in the roof of the chamber 9.

The floor 6 has a recess 11 of semi-circular transverse cross section that is positioned between the extensions 4, 5 and that extends into the body part for a short distance. The inner end of the recess is closed by an end wall 12 having a central opening 13 which is one end of a tubular extension that projects outwardly from the housing 1 as indicated at 14. The recess 11 has a longitudinal keyway 15 located as shown in Fig. 1.

A second tubular extension 16 projects from the housing 1 above extension 14 and communicates, at its inner end, with the mixing chamber 9.

Fluid flow through the inlets 4, 5 is controlled by a plate 17 which, in use, seats on the floor 6 but is shown, in Fig. 1 separated from the housing 1. The plate 17 is of generally rectangular form when seen in plan. The plate has two parallel, spaced, rectangular slots 18, 19 both open at one and closed at the other. The centre lines of the slots 18, 19 are spaced apart by a distance " X" equal to that between the centres of the orifices 7, 8. The slots 17, 18 are both of a width equal to the diameter of the orifices 7, 8.

Plate 17 has a depending shoulder 20 located centrally of one of its longer sides as shown. The shoulder 20 has a threaded bore 21 and an external longitudinal key 22. The shoulder is sized to fit into the recess 11 with the key 22 entering the keyway 15 in the recess.

Part 2 of the housing 1 also accommodates a second flow control plate 23 shown in Fig. 1 as separated from the housing.

The plate 23 is of generally T-shape when seen in plan. The stem 24 of the plate 23 is of a width equal the distance "X" - the distance between the centre lines of the slots 18, 19. Plate 23 carries a short length 25 of a rack on its upper face as seen in Fig. 1 adjacent the longer side of the plate.

The body part 2 is contoured to receive the plates 17, 23 which are entered into the part 2 via the open side thereof.

Plate 17 seats on the floor 6 with the shoulder 20 located in the recess 11, key 22 sliding into keyway 15. The engagement of shoulder 20 in the recess 11 allows plate 17 to move to and fro only in the directions of arrows 26.

Movement of plate 17 is effected by a tubular member 27 screw-threaded over a part 28 of its length adjacent one end and having an external collar 29 about midway between its ends.

Spaced peripheral recesses 30 accommodate "0" rings seals (not shown). A knurled end 31 enables a user to grasp and rotate the member 27 as will be described below.

Plate 23 is constrained by means not shown to move only in the direction of arrows 32 which lie at right angles to the arrows 26.

Movement of plate 23 is effected by a second tubular member 33 formed, adjacent one end, with outwardly projecting gear teeth 34. Member 33 also has an external collar 35 midway of its ends and also has a peripheral recess 36 for an 11011 ring seal (not shown). One end of member 33 is knurled as indicated at 37 to enable a user to grasp and rotate the member.

Prior to the entry of the plates 17, 23 into the body part 2, members 27 and 33 are pushed, after the 11011 ring seals have been placed in position in the appropriate recesses, into the tubular extensions 16 and 15 respectively from the left as seen in Fig. 1, the knurled ends being entered first. Movement of the members ceases when the collars 29 and 35 abut, respectively, the end wall 12 and that end of the extension 15 inside the mixing chamber 9.

The plates 17 and 23 are now entered into the body part 2 in the relative positions shown in Fig. 1. The threaded portion 28 of member 27 engages the threaded bore of shoulder 20 and rotation of member 27 draws the plate 17 into its final position inside the body part 2.

As plate 23 slides into the body part 2, rack 25 is engaged by the gear teeth 34 of member 33. Plate 23 is so positioned relative to plate 17 that the edges of the stem 24 of plate 23 lies along the central lines of the slots 18, 19, the plate 23 being thus positioned symmetrically with respect to those central lines and thereby to the centres of the orifices 7, 8.

When the plates 17, 23 are correctly positioned inside the body part 2, the end plate 2 is secured to the body part 2 to close the latter. Preferably, the part 2 and the plate 3 are of a suitable plastics material in which case, an adhesive may be used to fix the end plate to the body part.

The arrangement is such that movement of plate 17 controls the total flow of fluids through the orifices 7, 8. The plate 17 and the slots 18, 19 are so dimensioned that, at one end position of the plate 17, both orifices are fully uncovered and flow through them is a maximum. At the other end position of the plate 17 both orifices are fully covered and no fluid flow through them is possible. Between those two end positions, the orifices are covered to a greater or lesser extent and by the same amount.

Thus, by rotating the member 27, a user is able to regulate the total flow from the outlet 10, the respective rates of flow of the two fluids remaining the same.

The plate 23 is so dimensioned that, at one end position, one of the orifices is completely closed and flow therethrough is prevented. The other orifice is completely open and flow therethrough is at a maximum. In the other end position of plate 23, the one orifice is completely open and flow therethrough is then at a maximum, the other orifice being completely closed and flow therethrough is prevented. Between those two end positions, the plate one orifice is closed to some extent while the other is open to the same extent thereby ensuring that the total flow remains constant.

Thus, by rotating member 33, a user is able to control the relative proportions of the two fluids in the mixed flow through the outlet 10. Variation of the relative proportions of the two fluids in the mixed fluids leaving through the outlet 10 does not affect the total flow of mixed fluids, that being determined by the setting of the plate 17 as set by member 27.

When the mixer shown in Fig. 1 is used to control the flow of hot and cold water in a shower installation, member 27 controls the total flow of mixed water whilst member 33 controls the temperature of that flow by varying the proportions of hot and cold water in the mixed flow.

To reduce possible leakage between the plate 17 and the floor 6 round the orifices 7, 8, resilient seals are located in the inlets 4, 5. Fig. 1 shows such seals at 38 and 39. Each seal has an upper portion 40 that locates in the respective orifice, longitudinal positioning being ensured by an external shoulder 41 on the seal that seats on a step inside the inlet. Each seal is held in position by a helical spring 42 that seats, at one end, on the lower surface of the seal and, at the other end, on a retainer 43 that locks releasibly into the inlet.

It will be understood that if it is desired to provide control only over the relative proportions of the two fluids in the mixer, the plate 17 and the associated member 27 are omitted.

It will also be appreciated that plate 17 may of other shapes than that shown in Fig. I and one such other shape is seen in Fig. 2 at 44. Fig. 2 also reveals a plate 23 that is identical in form with plate 23 described above.

As can be seen from Fig. 2, plate 44 is of rectangular shape as is not slotted as is the case of plate 17 referred to above. Plate 44 has a shoulder 45 similar to shoulder 20 of plate 17. Shoulder 45 has a threaded bore 46 and an external longitudinal key 47. The plate 44 is movable to and fro in the direction of arrows 48 by a member (not shown) similar to member 27 referred to above.

Plate 44 is so dimensioned that, in one end position of its range of movement, both orifices 7, 8 are completely open whilst, at the other end of that range, both orifices are completely closed. Intermediate of the two end positions, the plate 44 closes both orifices to the same extent thereby controlling the total flow of the mixed fluids.

Plate 17 and 23 may be replaced by a single plate of the shape shown in Fig. 3. The plate 49 shown in Fig. 3 is of generally T- shape when seen in plan. Dimension "X" of the stem 50 of plate 49 has the same value as dimension "X" referred to above. However, the arms 51 of the plate 49 are wider that the arms of plate 23.

The plate 49 is supported in a carrier frame indicated diagrammatically at 52 in Fig.3 and which is similar to carrier tray 242 shown in Fig. 8 of European Patent Application No.

0384674 The frame 52 has a depending shoulder 53 with a threaded bore 54 and an external longitudinal key 55 Plate has a rack 56 similar to rack 25 described above Carrier frame 52 is adapted to permit movement of plate 49 relatively thereto to and fro in the directions of arrows 57 and is itself movable to and fro in the directions of arrows 58 at right angle to arrows 57.

Movement of the carrier frame 52 is effected by a member sm.lar to member 27 described above and that movement effect closure either wholly or partially of the orifices 7, %8 by the arms SA. thereby controlling the total fj.ow of the mixed 5P Movement of plate 49 to and fro in the directions of arrows 57 is effected by a member similar to member 33 referred to above and such movement allows the stem 50 of the plate to cover rsr: :r-! and uncovee the other rsf the orifices 7, 8 by the same amount In that way, the relative rates of flow of the two fluids are controlled as desired.

It wil:l be appreciated that, in embodiments in which control over the relative proportions of the two fluids only is required, plate 44 may be omitted from the arrangement shown ri Fig. 2 and frame 52 may be left out of the arrangement of Fig.

Claims (11)

Claims.

1. A control valve for fluids flows comprising a housing with first and second inlets and means for controlling the flow of fluids through the inlets in which the means comprises a control plate located within the housing adjacent the inlets, the plate being of substantially T shape when seen in plan and being movable within the housing in opposite directions both lying along the arms of the T and in a manner and to an extent such that movement of the plate in one direction closes one inlet and opens the other whilst movement of the plate in the opposite direction opens the one inlet and closes the other.

2. A control valve as claimed in claim 1 in which manually- operable means are provided for moving the plate, the means being operable from outside the housing

3. A control valve as claimed in claim 1 or 2 in which the plate has a stem with parallel sides spaced apart by a distance equal to the distance between the centres of the :i.nlets

4.A control valve as claimed in any one of the preceding claims in which the plate is symmetrically positioned with respect to the inlets when the fluid flows the two inlets are equal

5 A control valve as claimed in any one of the preceding claims in which the plate is so mounted as to be movable to and fro alone directions both of which lie along The stem of the plate and at right angles to the first mentioned directions

6 A control valve as claimed in claim S in which the plate is mounted in a carrier frame movable within the housing in said directions lying along the stem of the plate.

7. A control valve as claimed in claim G in which manually operable means are provided for moving the carry per frame such means being operable from outside the housing.

8. A control valve as claimed in claim 5 in which the T-shaped plate is associated with a second plate located within the housing and j.n cm owe proximity to the T shaped plate, the second plate being movable to and fro in opposite directions botb Zying along the stem Ot the T and at. right angles to the first mentioned directions, the arrangement being such that movemen@ of the second plate in one direction closes both inlets whilst movement of the second plate in the opposite direction opens both inlets.

9. A control valve as claimed in claim 8 in which the second plate has two spaced parallel slots extending in the direction of moment of the second plate.

10. A control valve as claimed in claim 9 in which each slot is centred an a different one of the inlets.

11. A control valve substantially as herein described with reference to and as illustrated by Fig 1 or Fig 2 or Fig, 3 of the accompanying drawings.

12 A shower installation including a control valve as claimed in any one of the preceding claims.