GB2244662A

GB2244662A - Mixing device for shower head

Info

Publication number: GB2244662A
Application number: GB9006699A
Authority: GB
Inventors: John Frederick Mash; Michael Peter Koller; Christopher John Kissane
Original assignee: Drayton Controls Engineering Ltd
Current assignee: Drayton Controls Engineering Ltd
Priority date: 1990-03-26
Filing date: 1990-03-26
Publication date: 1991-12-11
Anticipated expiration: 2010-03-26
Also published as: GB9006699D0; GB2244662B

Abstract

A mixing device is disclosed in the form of a shower head having an inlet chamber (3) to receive hot and cold water maintained apart by a meandering wall (17), and an outlet chamber (4) containing three annular walls (20) defining four annular outlet chambers, two of which communicate with the hot water section of the inlet chamber and two with the cold water section of the inlet chamber. The annular walls (20) taper and extend into grooves (22) in a rose (2). The rose has rings of outlet passages (23) intersected by the grooves so that the annular walls (20) divide each passage (23) into converging hot and a cold water outlet flow paths. <IMAGE>

Description

MIXING DEVICE The present invention relates to mixing devices and is applicable in particular to shower fittings and spray heads.

GB-A-2218926 discloses a mixing device comprising a chamber having inlets for the entry of respective fluids into the chamber, dividing means dividing the chamber into separate regions to maintain the respective fluids separate in the chamber, a plurality of outlets for the fluids, and means dividing the entrances of a plurality of the outlets each into zones communicating with respective ones of said separate regions of the chamber.

In this way, the fluids can mix as they exit the device, yet are maintained separate within the device.

In the field of domestic showers, it is important to keep the hot and cold water separate in this way.

Moreover it is a requirement that the spray should be reasonably uniform across the outlets and that sufficient mixing should occur to avoid excessive hot or cold spots. To assist in this, GB-A-2218926 proposes that the dividing means is a meandering wall to distribute the fluids across the chamber, the meandering being such that, taking a cross-section across the chamber, that section will cut alternate hot and cold water zones of the chamber.

According to a first aspect of the present invention, it is proposed to divide the chamber from the outlets by a separating wall containing apertures for the passage of the respective fluids into further separate regions which open into the outlets. In this way it is believed easier to make the hydraulic resistances between the inlets and outlets more equal or balanced, so assisting in distributing all the fluids more evenly to most of the outlets. Looking at it in another way, the apertures of the separating wall provide a plurality of paths for each fluid from inlet to outlet, instead of the single path of GB-A-2218926.

According to a second aspect of the invention there is provide a mixing device comprising a chamber having inlets for the entry of respective fluids into the chamber, dividing means dividing the chamber into separate regions to maintain the respective fluids separate in the chamber, a plurality of outlets for the fluids, and means dividing the entrances of a plurality of the outlets each into zones communicating with respective ones of said separate regions of the chamber,wherein a second chamber is provided having said outlets and having dividing means dividing the second chamber into separate regions for respective fluids, the chambers being separated by a wall having distribution apertures for distributing the fluids from the regions of the first chamber to the regions of the second.

Regarding the division of the outlets, GB-A2218926 proposes the use of individual, planar, projections extending to the outer ends of respective outlets and fitting against the sides of the outlets to seal the outlet zones from each other.

According to a third aspect of the invention, it is now proposed to provide a mixing device having a chamber to receive two fluids and divided by a wall or walls into distinct regions separating the fluids from one another, the chamber having an outlet wall containing outlet passages and the rear side of which has grooves intersecting a plurality of said passages and into which the dividing wall or walls extend to divide the entrance portion of each passage of that plurality into distinct zones communicating with respective regions of the chamber so as to receive respective fluids.

This enables the sealing of the distinct regions and the distinct zones of the passages to be implemented more easily, especially when the parts are constructed by moulding. Preferably, the wall or walls converge in the direction towards the exterior, improving the fluid mixing at the outlet ends of the passages. It also facilitates withdrawal from a mould during manufacture. The mixing is additionally facilitated if the passages also converge in the direction towards the exterior. One thus achieves converging stream of the fluids as they emerge from the passages.

According to a fourth aspect of the invention, there is provided a mixing device comprising means for feeding two distinct flows of fluid to an outlet passage, there being a wall intersecting the passage to define at its entrance region two distinct inlets to the passage for the respective flows, the passage having a substantially rectangular cross-section, with its longer dimension extending substantially at right angles to the length of the wall.

Having a rectangular outlet hole keeps the outlet aperture as small as possible whilst spanning a wide dividing wall, whilst the continuation of the tapering effect gives a narrowing outlet aperture that gives a powerful jet.

Another concept to be described hereinafter involves a spray-head having an array of passages such as described in the third and fourth aspect wherein the passages taper toward the exterior with a taper at that side of the passages nearer the centre of the array which increases in the direction away from the centre of the array.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which; Fig. 1 is a cross-section of the shower head of a shower fitting; Fig. 2 is a cross-section of a first moulded part of the shower head of Fig. 1; Fig. 3 is an underside view of first moulded part of Fig 2; Fig. 4 is cross-section of a second moulded part of the shower head of Fig. 1; Fig. 5 is an underside view of the second moulded part of Fig. 4; Fig. 6 is a view of the interior surface of a rose of the shower head of Fig.l; and Fig. 7 is a view of the exterior surface of the rose of Figures 6.

Fig. 1 shows the shower head of a shower fitting which is in essence the same as the shower fitting shown in Figures 1 to 4 of GB-A-2218826 with the exception of the construction of the shower head itself. What is shown and described in that case but not shown in the present Fig. 1 is the body of the shower fitting by which in use it might be held in the hand, that body containing two flexible conduits for hot and cold water, the conduits being acted upon by a manually controllable peristaltic flow control valve with a rotary control knob, all as shown and described in GB-A-2218826.

The shower head as shown in Fig. 1 comprises four plastics moulded parts which are: a cover member 1 extended to the right to form the upper part of the body; a rose 2; an inlet chamber member 3; and an outlet chamber member 4, the outlet member 4 being formed integrally with the lower portion 5 of the body of the shower fitting.

Fig. 1 additionally shows a screw 6 for attaching the inlet chamber member 3 to an upstanding boss 7 on the outlet chamber member 4, a screw 8 attaching the rose 2 to a downwardly extending boss 9 of the inlet chamber member 4 and an apertured gasket 10 providing a seal between the inlet and outlet chamber members.

The inlet chamber member will now be described with a reference to Figures 1, 2 and 3. This member has a upper circular wall 11 from the edge of which depends a cylindrical outer wall 12 to define a cylindrical inlet chamber into which open hot and a cold inlet pipes 13 and 14 respectively. The inlet chamber is divided into a hot water region 15 and a cold water region 16 by a meandering wall 17 the main portion of which follows annular paths concentric with the cylindrical outer wall 12. It will thus be seen that the two hot and cold regions produce alternating hot and cold portions when considered in a crosssection across the chamber, these portions being marked H and C in Figures 2 and 3.

The outlet chamber member 4 will now be described with reference to Figures 1, 4 and 5. It comprises a circular wall 18 from the edge of which extends an annular wall 19 defining an outlet chamber within which are three annular walls 20 depending from the plate 18.

As shown more particularly in Fig. 4, these walls have a tapering cross-section. Wall 18 has apertures 21 extending through it between the walls 20 and 19, these apertures being arranged in star fashion radially of wall 18 along six radii.

The resulting four annular chambers align with the four annularly extending passage portions in the inlet chamber member and in fact communicate one with the other by way of the apertures 21 in the plate 18.

Thus, in Fig.4, these annular passages in the outlet chamber are labelled H and C to show their correspondence with the passage portions in the upper inlet chamber. As shown in Fig. 1, the members 3 and 4 have interposed between them a gasket 10 which has the effect of sealing the join between these members thus keeping the hot and cold water passageways separate from one and another, i.e so that there is no mixing within the chambers.

The purpose of the construction is to provide a separating wall 18 between the inlet chamber and the outlet chamber with the apertures 21 so arranged as to make the hydraulic resistance of the various fluid paths more equal so that the incoming hot and cold water flows are distributed relatively uniformaly to the annular passageways of the lower chamber.

Specifically, the total aperture cross-section per unit length of flow path along each annular passageway increase towards the centre, i.e. away from the inlets.

The rose 2 will now be described with reference to Figures 1, 6 and 7. As will be apparent more particularly from Figures 1 and 6, the rose 2 contains three annular grooves 22 into which the walls 21 fit and seal, these grooves tapering to correspond with the tapering form of the walls 21. In addition, rose 2 is provided with three rings of rectangular section outlet passages 23 which are intersected by the grooves 22, the passages 23 have a tapering form corresponding to that of the walls 21 but of slightly wider dimension in order to allow the passage of water through the passageways on both sides of the walls 21. Owing to the way in which the wall 21 fit in the grooves 23, it will be seen that the hot and cold water flows are maintained separate, with the hot water flowing only down one side of its dividing wall and with the cold water flowing only down the other side. These flows will converge at the outlet owing to the tapering form of the walls 22 and passages 23, thus giving a good mixing effect with considerable spray force. The water also mixes with the air, giving a well aerated jet (champagne effect). It will be seen that the tapers are not symmetrical nor are they equal. The radially outer sides of the passages 23 and walls 21 are substantially parallel to the axis of the rose whilst the radially inner walls are at an angle and this angle increase radially outwardly, directing the flows in a diverging spray pattern.

Claims

Claims:

A mixing device comprising a first chamber having inlets for the entry of respective fluids into the chamber, dividing means dividing the chamber into separate regions to maintain the respective fluids separate in the chamber, a plurality of outlets for the fluids, and means dividing the entrances of a plurality of the outlets each into zones communicating with respective ones of said separate regions of the chamber, wherein a second chamber is provided having said outlets and having dividing means dividing the second chamber into separate regions for respective fluids, the chambers being separated by a wall having distribution apertures for distributing the fluids from the regions of the first chamber to the regions of the second.
2. A device according to claim 1, wherein the dividing means is a single continuous wall which meanders to proved a plurality of hot and cold passageway portions which alternate across the first chamber.
3. A device according to claim 1 or 2 wherein the dividing means define a plurality of annularly extending passageways.
4. A device according to claim 2 or 3, wherein the inlets open into outer passageway portions, so that the fluid flows in the first chamber extend on paths which extend progressively towards the central region of the first chamber.
5. A device according to any one the preceding claims, wherein the dividing means define for each fluid a flow path extending past ones of said distribution apertures having such spacing and flowthrough areas that, as considered along each flow path, the flow-through area per unit distance along the path increase in the downstream direction.
6. A device according to any one of the preceding claims and comprising a first, second and third moulded part, the first part having the dividing means of the first chamber and containing a space constituting the body of the first chamber, the second part having the separating wall, the dividing means of the second chamber and containing a space constituting the body of the second chamber, and the third part having said outlets.
7. A device according to any one of the preceding claims wherein the dividing means of the second chamber comprise a wall arrangement, and the chamber has an outlet wall containing, as said outlets, outlet passages and the rear side of which wall has grooves intersecting a plurality of said passages and into which the wall arrangement extends to divide the entrance portion of each passage of that plurality into distinct zones communicating with respective regions of the second chamber so as to receive respective fluids.
8. A mixing device having a chamber to receive two fluids and divided by a wall arrangement into distinct regions separating the fluids from one another, the chamber having an outlet wall containing outlet passages and the rear side of which has grooves intersecting a plurality of said passages and into which the dividing wall arrangment extends to divide the entrance portion of each passage of that plurality into distinct zones communicating with respective regions of the chamber so as to receive respective fluids.
9. A device according to claim 7 or 8, wherein the wall arrangement and the grooves converge in the direction towards the exterior ends of the outlet passages.
10. A device according to claim 9, wherein the wall arrangement does not extend completely to the exterior ends of the outlet passages.
11. A device according to claim 9 or 10, wherein the outlet passages converge towards their exterior ends.
12. A device according to claim 9, 10 or 11, wherein the convergence increases from passage to passage in the direction radially away from the central region of the plurality of passages.
13. A device according to any one of claims 8 to 12 wherein the passages have a substantially rectangular cross-section with their longer dimension extending substantially at right angles to the length direction of the wall arrangement.
14. A device according to any one of claims 8 to 13, wherein the wall arrangement comprises a plurality of concentric walls.
15. A mixing device comprising means for feeding two distinct flows of fluid to an outlet passage, there being a wall intersecting the passage to define at its entrance region two distinct inlets to the passage for the respective flows, the passage having a substantially rectangular cross-section, with its longer dimension extending substantially at right angles to the length of the wall.
16. A device according to claim 15, wherein the wall tapers so as to converge in the direction towards the exterior end of the passage.
17. A device according to claim 15 or 16, wherein the passage tapers so as to converge in the direction towards the exterior end of the passage.
18. A device according to claim 15, 16 or 17, whereing the wall does not extend to the exterior end of the passage.
19. A spray device substantially as hereinbefore described with reference to the acccompanying drawings.