GB2476351A

GB2476351A - Fluid flow control device

Info

Publication number: GB2476351A
Application number: GB1020423A
Authority: GB
Inventors: James Wesley Barnham
Original assignee: About Time Design Ltd
Current assignee: About Time Design Ltd
Priority date: 2008-03-27
Filing date: 2009-03-27
Publication date: 2011-06-22
Anticipated expiration: 2029-03-27
Also published as: GB2476707A; GB201020423D0; GB201020457D0; GB2476707B; GB2476539A; GB2476351B; GB2476542B; GB201020420D0; GB201020456D0; GB2476542A; GB2476540B; GB2476540A; GB201020461D0; GB2476541B; GB2476539B; GB201020434D0; GB2476541A

Abstract

A fluid flow control device, particularly an automatic fluid flow device configured to operate when an oversupply condition occurs, comprises first and second housing portions 5, 7 that are configured to be coupled one to the other by a plurality of fixings 45, 47 to define an internal void. A peripheral wall 51 of one of said first or second portions is curved between two adjacent fixings towards a peripheral wall of the other of said first or second portions so that on coupling the first and second portions together at least a portion of said curved peripheral wall is placed in compression.

Description

FLUID FLOW CONTROL DEVICE

The present invention relates to automatic fluid flow control devices, particularly but not exclusively to automatic liquid flow control devices. Particularly preferred embodiments of the present invention relate to automatic fluid flow control devices that are configured to operate when an oversupply condition occurs, and in one particularly preferred embodiment the device is operable to substantially shut-off (i.e. at least severely restrict) fluid flow until the device is reset.

Presently preferred embodiments of the present invention, and indeed the problems addressed by the present invention, are described hereafter with particular reference to domestic water-supply applications, but it should be noted that the scope of the present invention is not limited to a particular fluid type nor is it limited to a particular application. As such the following description should only be interpreted as being illustrative and should not be interpreted as limiting the scope of the present invention.

The device to be described can, for example, be used in domestic, commercial and industrial applications for the control of a variety of different fluids, including both gases and liquids.

In general terms, this application deals with improvements to automatic fluid flow control devices of the general type described in our earlier UK Patent GB2428800, and reference should be made to our earlier patent for a detailed description of the manner in which devices of this type operate.

Our previous UK patent GB2428800, the entire contents of which are also incorporated herein by reference, disclosed an automatic fluid flow control device in which an actuator and a valve magnetically interact to control the flow of fluid to an appliance such as, for example, a bathtub or sink.

Whilst the device disclosed in our prior patent operates flawlessly and has been extremely well received in the marketplace, our programme for continuous improvement has identified facets of that device which could be further improved.

An aspect of the present invention addresses the problem that as the spaces into which automatic fluid flow control devices are installed are typically quite restricted (for example the space between a bathtub and the wall), the device itself should be relatively thin so that it can readily be slotted into the space available behind a bathtub, for example. As such, the logical choice of shape for the device is for it to be a rectangular parallelepiped (i.e. a three-dimensional body with a rectangular cross-section) because such a shape meets the dual requirements of having sufficient width to provide space for the internal components and a relatively small depth. The device disclosed in our previous patent had roughly such a shape (see Figs 7 and 8 for example), and comprised a moulded body formed of top and bottom sections that were fastened together at a number of points (see Fig. 10 for example) around the periphery of the moulded body.

A disadvantage of this arrangement is that the provision of fixings in the vicinity of the inlet to the device (from the appliance overflow) necessarily increased the depth of the device and hence sometimes made it harder to fit the device in the space available behind some appliances, such as a bathtub for example. It would therefore be advantageous to remove the fixings in the vicinity of the inlet to reduce the thickness of the device, but the removal of those fixings would mean that the regions of the top and bottom sections in the vicinity of the inlet were only coupled together by the fixings at either end of the device, and as the device is manufactured from a plastics material that has the potential to creep (i.e. to change shape) over time there is the potential for leaks to occur.

To address this problem, an embodiment of the present invention provides a fluid flow control device comprising first and second portions that are configured to be coupled one to the other by a plurality of fixings to define an internal void, wherein a peripheral wall of one of said first or second portions is curved between two adjacent fixings towards a peripheral wall of the other of said first or second portions so that on coupling the first and second portions together the portion with the curved wall flexes so that at least a portion of said curved peripheral wall is placed in compression (against the other peripheral wall).

An advantage of this arrangement is that by placing at least part of the wall under compression, the likelihood of leaks occurring between the first and second portions can be reduced. Preferably, the portion with the curved peripheral wall is of a plastics material. More preferably both said first and said second portions are of plastics material. In one arrangement the peripheral walls of both said first and said second portions are curved.

It is preferred that the device is operable in the event of an overflow, and without requiring a supply of electricity, to automatically shut off or at least substantially reduce fluid flow through a fluid supply.

Other preferred features and advantages of the present invention are set out

elsewhere in this specification.

Various aspects of the teachings of the present invention, and arrangements embodying those teachings, will hereafter be described by way of illustrative example with reference to the accompanying drawings, in which: Fig. 1 is a front isometric view of a device according to a preferred embodiment of the present invention; Figs. 2 to 7 are, respectively, a front elevation, a rear elevation, a left side elevation, a right side elevation, a top plan view and a bottom plan view of the device depicted in Fig. 1; Fig. 8 is an exploded isometric view of the device depicted in Fig. 1 with all of the components of that device shown; Fig. 9 is an isometric view of a top portion of an actuator chamber; Fig. 10 is an isometric view of a bottom portion of the actuator chamber; Fig. 11 is an isometric view of a float assembly; Fig. 12 is an exploded isometric view of the assembly shown in Fig. 11; Fig. 13 is a cross-sectional view of the bottom portion along the line A-A shown in Fig. 10 and a cross-sectional view of a float carrier of the float assembly along the line B-B shown in Fig. 11; Fig. 14 is a modification of the arrangement shown in Fig. 13; Fig. 15 is an isometric view of a float carrier that comprises part of the float assembly depicted in Fig. 11; Fig. 16 is a view of part of the float carrier shown in Fig. 15 and a magnet; Fig. 17 is a sectional view of part of the float carrier along the line C-C of Fig. 16; Fig. 18 is a cross-sectional view through the device along the line D-D of Fig. 6; Fig. 19a is an isometric view of a valve assembly, and Fig. 19b is a cross-sectional view along the line E-E in Fig. 19a; Fig. 20 is a front isometric exploded view of a valve for the valve assembly of Fig. 19;and Fig. 21 is a rear isometric exploded view of the valve shown in Fig. 20; Fig. 22 is a perspective view of a coupling for use with the device of Fig. 1; Fig. 23 is a schematic representation of a cam track; Fig. 24 is a plan view of the coupling shown in Fig. 22; and Fig. 25 is a side elevation of the coupling shown in Fig. 21.

The automatic fluid flow control device described hereafter operates in a similar way to that in which the device disclosed in our earlier United Kingdom patent operates, and reference should be made to that document for additional details of how the device operates.

Referring now to the drawings, the fluid flow control device 1 is automatically operable, without requiring an electrical supply, to shut-off or at least substantially restrict the flow of fluid to an appliance in the event that an oversupply of fluid (referred to hereafter as an overflow condition) should occur.

The device 1 comprises an actuator chamber 3 formed by a top portion 5 and a bottom portion 7 that are coupled together by a plurality of fixings 9, in this particular case screws.

The top portion 5 includes an inlet 11 in which a barbed coupling 13 has been inserted. The barbed coupling 13 is configured to be connected to the overflow outlet of an appliance (not shown) such as a bathtub, for example by means of a flexible coupling, in particular by a braided flexible coupling.

The bottom portion 7 includes an outlet 15 in which a second barbed coupling 17 has been inserted. The barbed coupling 17 is configured to be connected to a drain inlet (not shown), for example by means of a flexible coupling. The bottom portion further comprises left and right tubular wings 19, 21 in each of which a valve assembly 23 is securely received.

The valve assemblies 23 (see also Fig. 19) comprise a first component 25 which includes an outlet 27 that can be coupled, for example by means of a flexible coupling, to a tap of a bath, and a second component 29 which includes an inlet 31 for coupling, for example by means of a flexible coupling, to a fluid supply.

As shown in Fig. 19a, the peripheral wall of the first component 25 of the valve assembly includes, at or near the edge that is closest to the second component when the two components are coupled together, an external tactile formation 25a. Likewise, the peripheral wall of the second component 29 of the valve assembly also includes, at or near the edge that is closest to the first component when the two components are coupled together, an external tactile formation 29a. In the preferred embodiment the two tactile formations comprise projections (preferably identical triangular projections), and the arrangement is such the first and second parts can be screwed together until the two tactile formations are aligned, at which point the alignment of the tactile formations signifies that the first and second components have been coupled together to the correct torque setting. In the preferred embodiment the first and second components are each provided with a pair of tactile formations for alignment with one another.

The valve assemblies are securely received within the tubular wings 19,21 of the by pushing the outlet end of each valve assembly upwards (in the orientation shown in Fig. 1) through the respective tubular wing 19,21 until a plurality of fingers 33 (see also Fig. 10) snap-fit behind a circumferential wall 35 formed in the periphery of the valve assembly. The fingers are configured to resiliently and outwardly deform as a peripheral shoulder 37 on the first component of the valve assembly is pushed through the tubular wing, following which the fingers inwardly snap-fit behind the aforementioned circumferential wall 35. As will be appreciated by persons skilled in the art, once the fingers 33 have snapped behind the wall 35, the valve assembly can no longer be withdrawn from the tubular wing of the actuator chamber 3. The first component 25 of each valve assembly is also provided with a shoulder 36 (see Fig. 19) that bears against the respective wings 19, 21 to prevent the valve assemblies from being pushed through the wings.

Referring now to Fig.7, in a particularly preferred embodiment of the invention the bottom portion 7 of the actuator chamber 3 is provided with a pair of grooves 38 (for each valve assembly) into which the aforementioned aligned tactile projections (on the periphery of the first and second components of the valve assembly) slide as the valve assemblies are pushed into the respective tubular wings 19, 21 of the actuator chamber 3. As will be appreciated, if only a single set of alignable formations are provided, then only one groove need be provided in the bottom portion 7.

The receipt of the aligned tactile formations in the grooves 39 serves two functions. In the first instance it ensures that the valves within the valve assemblies are correctly aligned with the actuator within the actuator housing 3 so that magnets carried by the actuator can magnetically interact with magnets carried by the valves. In the second instance, it ensures that the second component of the valve assembly cannot be decoupled (to give access to the valves) from the first component whilst the valve components are received within the tubular wings 19, 21 of the actuator chamber 3.

The snap-fit of the fingers 33 behind the circumferential wall 35, the receipt of the aligned tactile formations in the grooves 39 and the abutment of the shoulders 36 with the wings together function as an effective tamper prevention mechanism as the valve assemblies cannot readily be removed from the actuator chamber 3 and cannot readily be disassembled once the valve assemblies have been pushed into the tubular wings.

Referring now to Fig. 8 of the drawings, the top 5 and bottom sections 7 of the actuator chamber define an internal void in which an actuator in the form of a float assembly 41 is provided. Magnets 43 (which, in the preferred embodiment are of Samarium Cobalt) are inserted into a component of the float assembly 41 and are carried with the assembly as it moves.

The first 25 and second 29 components of the valve assembly also define an internal void within which a flap valve 39 is provided, the flap valve 39 being shown in more detail in Figs. 20 and 21 of the accompanying drawings.

To assemble the device, the flap valve 39 is assembled, following which the valve is secured within the first component 25 of the valve assembly and the second component is screwed to the first component until the aforementioned tactile formations 25a, 29a are aligned. This process is then repeated, in this illustrative example, for the other valve assembly.

Once the valve assemblies have been constructed, they are aligned with the bottom section so that the tactile formations 25a, 29a can move into the corresponding grooves 38 and are then pushed into the respective wings until they lock in place.

The float assembly is then constructed, in a manner that will later be described, and magnets are inserted into each of the two magnet holders formed in a component of the float assembly. The completed float assembly is then placed in the internal void defined by the bottom section 7 of the actuator chamber, following which the top section is securely coupled to the bottom section.

Once this has been completed and any desired additional fittings (such as the aforementioned barbed connectors 13) have been inserted, the device is ready for testing and if that testing should be completed satisfactorily, sale.

Figs. 9 and 10 are isometric views of, respectively, the top section 5 and the bottom section 7 of the actuator chamber 3. As shown in Fig. 9, the top section is generally rectangular in plan view and is provided with four internally threaded through-holes 45, one in the vicinity of each corner.

The bottom section 7 comprises four complementary internally threaded through holes 47 that are arranged to correspond in position to the through-holes 45 in the top section 5 when the top section is mounted to the bottom section 7. The bottom section also comprises a peripheral wall 49 that fits within a groove (not shown) in the underside of a complementary peripheral wall 51 of the top section (typically with a sealing member such as an 0-ring in between them) when the top section is fitted to the bottom section.

As will be appreciated from Figs. 2 or 3, for example, when the top and bottom sections are secured together by screws passed through the aligned through holes 45, 47, there are regions 53 (one of which is shown in Fig. 2, the other of which is shown in Fig. 3) of the interengaged top section peripheral wall 51 and bottom section peripheral wall 49 that are quite a large distance, for example more than 5 cm, from the nearest securing screws. Because of the aforementioned problem of plastic creep there is the potential for the shape of the peripheral walls to change over time, and leaks can occur in areas such as regions 53 where the nearest fixing are some distance away.

To address this problem instead of forming the peripheral wall 51 of the top section 5 so that it is parallel to the peripheral wall 49 of the bottom section 7, we have instead formed the peripheral wall 51 of the top section 5 so that each long side is slightly convex (i.e. curved towards the peripheral wall 49 of the bottom section 7) between through holes 45 at adjacent short ends of the top section 5.

The effect of this is that when the top and bottom sections are fitted together and screws are screwed into the aligned screw holes 45, 47 the top section flexes very slightly and a compressive force is generated (at least) in the aforementioned regions 53 which compressive force helps to hold the peripheral walls together and hence helps reduce the likelihood of leaks occurring even if plastic creep should occur. An alternative, but functionally equivalent arrangement, would be to form the peripheral wall 49 of the bottom section 7 so that it is each long side of the bottom section that is slightly convex (i.e. curved towards the peripheral wall 51 of the top section 5).

As an illustration we have found that a curvature which extends the mid point of the long sides of the peripheral wall 49, 51 by 1 mm or less relative to the peripheral wall adjacent the fixings provides sufficient compressive force to address the potential for leaks in the event that plastic creep occurs.

Referring now to Figs 11 and 12 of the drawings there is depicted, respectively, an isometric and exploded isometric view of the float assembly 41. The float assembly comprises upper 53 and lower 55 foam pads that are secured to a float carrier 57 by fixings 59 that engage with four bayonet pins 61 (one at either end of each bayonet) that pass through the foam pads and the float carrier 57.

The float carrier 57 is in the form of a spider and comprises a generally planar section 63 that terminates in a peripheral wall 65 which forms part of first and second holders 67 into each of which a magnet 43 is inserted. The float carrier comprises a tubular portion 69 that extends upwardly and downwardly from the planar section and fits within holes 71 formed in the upper and lower foam pads 53, 55.

As shown in Fig. 13, the bottom section 7 comprises a hollow column 73 that is directly connected to the outlet 15. The column includes a plurality of openings 75 at its base that allow fluid which enters the actuator chamber to exit to a drain. However, as is described in more detail in our previous patent, if an overflow event occurs fluid will enter the actuator chamber via the inlet in the top section (not shown) more quickly than it can exit from the chamber via the openings 75 and the level of fluid within the chamber will increase until the fluid spills over the upper end 77 of the column 73 to exit from the chamber through the column 73.

The tubular portion 69 of the float carrier is sized to fit over the column 73 so that the float assembly (of which only the float carrier is shown for clarity) is located within the bottom section in such a fashion that the float carrier can slide up the column in the event of an overflow to move the magnets 43 and hence cause the valves in the valve assemblies to operate to shut-off or at least substantially reduce the flow of fluid therethrough. Further details of the way in which this happens can be found in our previously granted UK patent.

As aforementioned, it is popular for persons to use products such as bath bombs and it is not unusual for these bath bombs to include solid matter such as flower petals, leaves or confetti. This material tends to float and as such it can flow into the actuator chamber 3 if an overflow condition should occur. Once this material is in the chamber it can form a paste-like gunge that can become lodged between the outer surface of the column 73 and the inner surface of the tubular portion 69. As the gunge builds up between these surfaces it is possible to reach a point where the adhesive force provided by the gunge between the surfaces is of such a magnitude that the float assembly no longer rises when fluid is introduced into the actuator chamber 3, whereupon the device can fail to operate.

To alleviate this situation we have provided the inner surface of the tubular portion with a plurality of parallel, longitudinally extending ribs 79 that, in the first instance, provide areas 81 of increased separation between the inner surface of the tubular portion 69 and the outer surface of the column 73 to promote fluid flow between the surfaces that helps to clean out any gunge that forms between them. The provision of a ribbed internal surface also acts to reduce the surface area of the tubular portion internal surface that is immediately adjacent the outer surface of the column, to reduce the area of the tubular portion inner surface that could be adhered to the outer surface of the column, to reduce the extent of any adhesive force that the gunge may provide, and hence to reduce the likelihood of gunge within the device causing the device to fail to operate as expected.

An alternative, but functionally equivalent arrangement, would be to provide a tubular portion 69 with a smooth inner surface and to provide the outer surface of the column with a plurality of parallel ribs.

In another arrangement, structures other than ribs may be formed on one of the two surfaces. For example, the structures may comprise a plurality of discrete lands or pins extending from one surface towards the other.

As the float assembly carries magnets 43 that interact with magnets in the valve assemblies, it is important for the float assembly to be properly orientated within the actuator chamber 3 so that the magnet polarities interact to cause the valves in the valve assemblies to close in the event of an overflow.

However, as the device is capable of being opened by the user, for example to enable the user to clean the inside of the device, there is a danger that the user may put the float assembly back into the bottom section upside down -in which case the valve assemblies may not operate as intended in the event of an overflow.

To address this problem a preferred embodiment of the present invention provides, as indicated in Fig. 14, a modified bottom section 7 where the exterior surface of the column 73 is thickened to form a shoulder 75 that interacts with the ribs 79 on the internal surface of the tubular portion 69 to prevent the float assembly from being inserted into the bottom section in any orientation other than that shown in Fig. 14.

In another arrangement not shown in the drawings, the shoulder may be replaced by a circumferential rib (which need not be continuous) that runs round the periphery of the column at a point spaced from the base thereof. Other functionally equivalent arrangements will be immediately apparent to persons skilled in the art.

In either case, the advantage of this embodiment of the present invention is that it is impossible for a user to insert the float assembly into the bottom section incorrectly.

Referring now to Fig. 15, there is provided an isometric view of the float carrier 57 of the float assembly 41. As aforementioned, each end of the float carrier includes a magnet holder 67 that are each formed, at least partly, as an extension of a downwardly extending peripheral wall 65 of the carrier 57.

Referring now to Fig. 16, which comprises a view of part of the carrier 57 shown in Fig. 15 together with a magnet 43, the holder 67 comprises an outer wall 83 that comprises an extension of the aforementioned downwardly depending peripheral wall 65 and an arm 85 that terminates with a hook 87 and is deformable towards the tubular portion 69 of the carrier 57.

The magnet 43 includes a pair of chamfered corners, and as shown in Fig. 17 the outer wall 83 and arm (not shown) define a cavity that has a complementary shape to that of the magnet.

When the magnet 43, as orientated in Fig. 16, is inserted into the holder the magnet fills the entirety of the cavity shown in Fig. 17 and the hook 87 fits under a lower edge 89 of the magnet 43 to retain it in the holder 67. If, however, the magnet orientation should be reversed (i.e. so that the chamfered corners point towards the bottom of the page) then it is impossible to insert the magnet into the holder to such an extent that the hook 87 fits under the lower edge 89 of the magnet. As such the hook does not retain the magnet in place and the magnet will tend to fall out of the holder.

It is the case, therefore, that if a user should remove the magnets 43 from the carrier 57 for any reason then it will be impossible for them to put the magnets 43 back into the holders incorrectly, and as such it is impossible for the user to orientate the magnets in such a way that they no longer correctly interact with the magnets in the valve assemblies to operate the device in the event of an overflow.

In a particularly preferred embodiment of the present invention, as shown in Fig. 12, at least the lower foam pad 55 is formed of a material that is both buoyant and resistant to compression. The advantage of this arrangement is that once the magnets have been inserted into the holders 67 and the lower foam pad 55 has been installed on the carrier 57 the foam pad acts to resist movement of the arm 85 towards the tubular portion 69 and hence acts to resist disengagement of the "lock" provided by the engagement of the hook 87 with the lower edge 89 of the magnet 43.

Thus by virtue of this arrangement it is not only impossible for a user in insert a magnet into the holder in an incorrect orientation, but it is also difficult for the user to remove the magnets from the holders 67 in the first place.

In a preferred embodiment of the invention at least the lower foam pad 55 is of Plastazote®, a closed cell cross-linked polyethylene foam available from Zotefoams PLC of 675 Mitcham Road, Croydon CR9 3AL.

Fig. 18 is a cross-sectional view through the assembled device 1 along the line D-D of Fig. 6. As shown the top section 5 and bottom section 7 cooperate to define an internal cavity in which the float assembly 41 is received. The float assembly includes a pair of magnets at either end which cooperate with magnets carried by valves 91 of the valve assemblies 23.

The valve assemblies 23 are inserted into each of the wings 19, 21 of the bottom section 7, and the first component 25 of each assembly is internally structured to form a valve seat 93 against which the valve 91 can move to shut off or at least substantially restrict fluid flow through the valve assemblies 23 from the inlets 31 to the outlets 27 thereof.

As shown in Fig. 19b (which is a cross-sectional view through one of the valve assemblies) the valve 91 of each assembly is pivotally mounted in the valve assembly by means of a pivot pin 95 inserted into the valve assembly via a port 97 that is shown in Fig. 19a.

Fig. 20 is a front isometric exploded view, and Fig. 21 is a rear isometric exploded view, of a valve 91 for the valve assembly 23 of Fig. 19. As will now be explained with reference to Figs. 20 and 21, the valve 91 is configured to reduce the incidence and/or effect of pressure perturbations on the fluid pressure measurements we take to determine whether the bleed rate of fluid past the valve when the valve is in its closed position is appropriate.

The valve 91 comprises a valve body 99, a valve soft face 101 (which may be formed of a resilient material to provide a good seal against the valve seat) and a soft face holder 103. The valve body 99 includes a generally square depression 105 that has a pair of chamfered corners so that the depression can accommodate a similarly shaped magnet 107 in only one orientation (i.e. with the chamfered magnet corners uppermost as shown).

The rear of the valve body 99 is formed with a through-hole 109 with which the pivot pin 95 engages to allow the assembled valve to pivot about the pin 95 to engage with the valve seat 93.

The soft face holder 103 includes four projections 111 that fit through corresponding holes 112 in the valve soft face 101 and can be fixed, for example by ultrasonically welding, to sandwich the magnet 107 between the soft face 101 and the valve body 99. The valve soft face also includes a fifth through-hole 113 that registers with a smaller through hole 115 formed in the soft face holder 103, and the underside of the soft face holder includes a projection 117 that fits within a generally half-moon shaped extension 119 of the depression 105 in the valve body 99.

The generally half-moon shaped extension 119 functions, in the first instance, to reduce the quantity of plastics used to manufacture the valve body 95 and by virtue of this to reduce the chance of warping that might otherwise occur if the half-moon depression were filled with plastics material. The half-moon extension 119 also receives the projection 117 on the underside of the soft face 101, which projection ensures that the soft face can only be installed in the valve in one orientation with respect to the valve body 99.

This last feature is important as the valve soft face 101 further comprises a channel 121 in the outer peripheral rim of the valve soft face that provides a means for fluid to bleed past the valve when the valve is abutted against the valve seat 93 in the closed valve position, and this bleed channel should be located towards that end of the seat 93 that is closest to the second component 29 of the valve assembly 23.

The advantage of this arrangement is that if any fluid should enter into the valve when the valve is under pressure and open, the fifth through-hole 113 and the smaller through-hole 115 that is registered with it provide a means for that fluid (in particular for any fluid filling the half moon extension 119) to quickly exit from the valve when the valve is closed thereby avoiding or at least reducing the pressure perturbations associated that can occur when fluids exits more slowly from within the valve. A channel is preferred to a hole through the valve as a channel is less likely to be blocked by any detritus carried by the fluid flowing through the valve assembly.

Referring now to Figs. 22 to 25, the barbed coupling 13 comprises a first tubular portion 123, and a second tubular portion 125 set at an angle to the first portion. The second tubular portion carries a plurality of barbs on its external surface and is configured to be securely received within a flexible coupling (not shown) that couples the fluid flow control device to the overflow outlet of an appliance. The first and second tubular portions meet at a shoulder 127 that includes a plurality of tactile formations 129, in this instance a plurality of triangular projections, and an upstanding finger plate 131 to which pressure can be applied to move the barbed coupling with respect to the inlet or outlet of the actuator chamber 3.

As will be appreciated by persons skilled in the art, whilst flexible couplings are indeed flexible they cannot easily be bent through small radius turns. As such, if the second tubular portion were to be axially aligned with the first tubular portion, then in many circumstances it is likely that the flexible coupling would need to be bent through one or two relatively small radius turns. By canting the second tubular portion (with respect to the shoulder 127), the extent to which the flexible coupling needs to be bent can be reduced, and hence installation of the device can be eased. In the preferred embodiment the second tubular section 125 is canted by about 10 to 30 degrees towards the horizontal.

The first tubular portion could be secured in the inlet or outlet of the actuator chamber 3 by any of a number of different mechanisms (for example, by means of complementary screw-threads), but in the preferred arrangement the outer peripheral surface of the first tubular portion 123 includes a plurality of raised lands 133 (in this instance four lands) that function as cams and fit within complementary cam tracks 135 (Fig. 23) formed as indentations in the internal surface of the inlet 11 and outlet 15 of the actuator chamber 3.

The cam tracks 135 are generally L shaped, and a leading surface 137 of each of the lands is inclined to form a cam surface that causes the first tubular portion 123 to inwardly deform as the lands 133 ride over a triangular cam 139 provided within the cam track. The first tubular portion 123 outwardly expands once the lands have passed their respective cams and arrived at a rest position 139, thereby securing the first tubular portion in the inlet or outlet of the actuator chamber 3.

As will be appreciated by persons skilled in the art, by providing four lands and four corresponding cam tracks the second tubular portion 125 can be orientated at one of four predefined orientations with respect to the top portion 5 of the actuator chamber.

In effect, the canted second tubular portion can be pointed in whichever one of four (in this instance) directions is most appropriate for the particular circumstances in which the device is to be installed. It will also be appreciated that the number of lands and corresponding cam tracks defines the number of positions in which the second portion can be orientated. For example if three lands and corresponding cam tracks are provided the second tubular portion can be orientated at one of three predefined orientations.

As shown in Fig. 22, each of the tactile formations 129 is aligned with a land 133, and the exterior of each of the outlet and inlet peripheral walls is provided with a plurality of tactile formations 141 that are each aligned with the corresponding rest position 139 within each of the cam tracks. The effect of this is that someone working to install a device that they cannot easily see can insert the first tubular portion 123 of the barbed coupling 13 into the inlet 11, for example, and then rotate the coupling 13 using the finger plate 131 until they can feel that the tactile formations 141 on the exterior of the inlet 11 are aligned with the tactile formations 129 on the shoulder 127. When the tactile formations are so aligned, the person installing the device knows that the lands are properly located in their respective rest positions 139.

As shown in Figs. 22 and 25, the first tubular portion 123 includes a port 143 that functions to provide a second pathway from the interior of the actuator chamber 3 for fluid egress. In our previous patent, a so-called "gunge plug" was provided to ensure that fluid flowed out of the actuator chamber 3 at a slower rate than it entered, and by incorporating the port 143 into the first tubular portion the gunge plug can be dispensed with.

As aforementioned, the automatic fluid flow control device herein described operates in a similar same way as the device disclosed in our earlier United Kingdom patent, and reference should be made to that document for a more detailed description of the manner in which the device operates. In general, in the event of an overflow, fluid travels into the actuator chamber 3 via the inlet 11. Fluid leaves the chamber 3 (via port 15) more slowly than it enters, and as the fluid level within the chamber 3 rises, the float assembly (which carries a magnet adjacent each valve assembly) rises and each magnet exerts a repulsive magnetic force on magnets mounted in a valve in each of the valve assemblies. The magnetic force causes the valves to move into the flow of fluid moving through each of the valve assemblies, whereupon the fluid drives the valves closed thereby interrupting the flow of fluid into the appliance.

To reset the device, the taps of the appliance are turned off, whereupon the fluid pressure either side of the valves equalises by virtue of a small bleed past the valves and the valves return to their original position under gravity and the influence of an attractive magnetic force from the falling float assembly as the fluid drains from the actuator chamber. Once the valves have returned, the taps (where the appliance is a bath or sink) can again be turned on to allow fluid to flow into the appliance once more.

It will be appreciated that whilst various aspects and embodiments of the present invention have heretofore been described, the scope of the present invention is not limited to the particular arrangements set out herein and instead extends to encompass all arrangements, and modifications and alterations thereto, which fall within the scope of the appended claims. For example, whilst the embodiments herein described all refer to a flow control device that has two valve assemblies, it will be apparent to persons skilled in the art that a single valve assembly, or more than two valve assemblies may instead be provided.

It should also be noted that whilst the accompanying claims set out particular combinations of features described herein, the scope of the present invention is not limited to the particular combinations hereafter claimed, but instead extends to encompass any combination of features herein disclosed irrespective of whether that combination of features has been claimed at this time.

Claims

CLAIMS1. A fluid flow control device comprising first and second portions that are configured to be coupled one to the other by a plurality of fixings to define an internal void, wherein a peripheral wall of one of said first or second portions is curved between two adjacent fixings towards a peripheral wall of the other of said first or second portions so that on coupling the first and second portions together at least a portion of said curved peripheral wall is placed in compression.
2. A device according to Claim 1, wherein the portion with the curved peripheral wall is of plastics material.
3. A device according to Claim 1 or 2, wherein both said first and said second portions are of plastics material.
4. A device according to any preceding claim, wherein the peripheral walls of both said first and said second portions are curved.