WO2004104306A1

WO2004104306A1 - A water tap

Info

Publication number: WO2004104306A1
Application number: PCT/GB2004/002114
Authority: WO
Inventors: Oczan Ozagir
Original assignee: Astracast Plc
Priority date: 2003-05-19
Filing date: 2004-05-17
Publication date: 2004-12-02
Also published as: GB0523387D0; GB2417547B; GB2417547A

Abstract

A water tap (10, 100) which comprises: a tap body (11, 31, 110); first, second and third inlets (12, 13, 14, 120, 130, 140) for supplying respectively hot water (H), cold water (C) and a further liquid (F) to the interior of the tap body; a discharge spout (15, 32, 150) mounted on the tap body (11, 31, 110) and having a discharge outlet (18, 180) at or near its free end; an internal valve assembly (20, 24, 25, 360) in the tap body for selectively controlling the admission of liquids to the interior of the tap body via the first, second and third inlets and the discharge of selected liquid(s) from the tap body to the discharge spout; and, a single operating lever (33, 190) pivotally mounted on the tap body for adjustment movement about a substantially vertical axis and along a predetermined first arc of movement (210), said lever being coupled with the valve assembly and being operative to selectively admit hot water (H) and / or cold water (C) to the tap body via the respective first and second inlets according to the position of adjustment along the arc of movement, said lever also being movable along an arcuate extension to the arc of movement (250) in which the valve assembly is adjusted to block admission of hot water (H) and cold water (C) and to allow admission only of further liquid (F) via the third inlet: in which the valve assembly defines within the tap body three separate waterways (Wh, Wc, Wf) corresponding to the first, second and third inlets, and each dedicated, under adjustment of the valve assembly, to block or to allow flow of hot water (H) only, cold water (C) only, or further liquid (F) only along the respective waterways (Wh, Wc, Wf) and without any mixing of the liquids within the interior of the tap body.

Description

A WATER TAP

This invention relates to a water tap having a tap body, separate connections on the tap body for receiving supplies of hot water, cold water and filtered water, a common discharge spout mounted on the tap body, and valves means for controlling the supply of hot water, cold water and filtered water from the tap body to the discharge spout.

It is well known to provide a common discharge spout, for discharging hot and / or cold water, and the spout may have two separate passages, each dedicated to one of the hot and cold water supplies, and which have discharge outlets located adjacent to, or close to each other, and so that a single jet of hot and / or cold water can be discharged. Alternatively, the spout may have a single passage, along which hot only, or cold only water may pass, upon opening of the hot or cold valves. In addition, the tap body may incorporate a pre-mixing chamber, in which hot and cold water supplies maybe mixed (upon opening of both of the hot and cold water valves), prior to the mixed supply passing along the single passage in the discharge spout to be discharged as a mixed jet of hot and cold water.

It is also known to provide a discharge spout with three separate dedicated passages, corresponding to hot, cold, and filtered water supply, and this has the claimed advantage that there will be no "contamination" of the filtered water passage, in that it will always only convey filtered water. However, the fabrication costs of providing three separate routes for the three different water supplies through the tap body, and the provision of three separate discharge passages within the common discharge spout, make this an expensive item which is not suitable for the mass market which requires the facility to obtain occasional supply of filtered water (in addition to more regular usage of hot and / or cold water), but not at premium cost.

The invention has therefore been developed to address this need in a way that is effective, but simpler in construction and therefore can be made available at a competitive price.

According to one aspect of the invention there is provided a water tap having a tap body, separate connections on the tap body for receiving supplies of hot water, cold water and filtered water, a common discharge spout mounted on the tap body, and valve means for controlling the supply of hot water, cold water and filtered water from the tap body to the discharge spout, in which: the discharge spout is provided internally with two separate discharge passages only, which lead to a common discharge outlet of the spout; the tap body defines a route for hot water only which communicates with a dedicated first one of the two separate discharge passages in the discharge spout which can therefore discharge hot water only; the tap body also defines a separate incoming route for each of cold water and filtered water, and a common outgoing route for one or the other only of cold water and filtered water and such common outgoing route communicating with a second of the two separate discharge passages and which is dedicated to said common outgoing route; the valve means includes a dual purpose valve which is mounted on or in the tap body and is operative selectively to divert the communication of the incoming route for cold water, or filtered water, with the common outgoing route depending upon whether cold water discharge or filtered water discharge is required, and to control the flow along said common outgoing route; and a single lever is mounted on the tap body to control the operation of the valve means. Therefore, in a water tap according to the invention, two discharge passages only are provided in the discharge spout, and the first of which is dedicated to supply hot water only, whereas the second can selectively discharge cold water or (cold) filtered water only, under the control of the dual purpose valve, and depending upon whether the valve diverts the incoming cold water route or the incoming filtered water route with the common outgoing route.

The dual purpose valve therefore can be quite simply a standard cold water control knob, button or handle, and a separate diverter valve can be sourced economically by utilising existing technology available in bath taps or similar, or incorporated into the tap body (diverters are used to divert water flow between a common discharge spout to fill the bath and a supply line leading to a shower fitting or similar).

Alternatively, the dual purpose valve may be a (single) integrated valve, in the sense that it has the dual function of (a) diverting and (b) directing flow of filtered water, or cold water via the common outgoing route. The flow along the second discharge passage can be changed easily between (unfϊltered) cold water supply and filtered water supply, and if there are any consumer concerns that the passage has previously conveyed unfiltered water, it is only necessary to let the filtered water flow run for a little longer to flush out the passage, before filling a glass, jug etc with filtered water.

Conveniently, the diverter valve is arranged to revert automatically to cold water routing to the common outgoing route (after operation to route filtered water), and this reversion may be after a predetermined time period e.g. for long enough to fill a glass, and under spring or other return control.

A second aspect of the invention relates to a water tap having a tap body, first, second and third liquid inlets to the tap body for supplying, respectively, hot water, cold water and further liquid to the interior of the tap body, a discharge spout mounted on the tap body and having a discharge outlet at or near its free end, and a single operating lever mounted on the tap body and operative to control the supply of liquid from the interior of the tap body to the discharge spout.

It is known to provide a water tap with a single operating lever, and which has a range of pivotable adjustment about a generally vertical axis relative to the tap body, in order to vary the relative proportions of hot and cold water admitted to the tap body via the respective first and second inlets, and therefore also the relative proportions of hot and cold water discharged from the outlet of the discharge spout. The adjustment about the vertical axis allows the proportion of hot to cold water to vary from 100:0% and 0:100% as required, depending upon the position taken by the lever along a defined arc of movement, with one end of the arc corresponding to 100% hot and 0% cold, and the other end of the arc corresponding to 100% cold and 0% hot. The lever is also pivotable about a generally horizontal axis in order to control the volumes of hot and cold water admitted for any position of adjustment along the arc of movement.

It is further known e.g. from US 6029699 to provide an arcuate extension to the arc of movement of the operating lever, and to arrange that the admission of hot and cold water to the interior of the tap body is blocked when the lever takes-up a position along the arcuate extension, and in which a further liquid is admitted to the interior of the tap body via the third inlet and then is discharged from the tap body to the discharge spout. The further liquid can be any desired liquid beverage, including filtered water, chilled water, aerated water or other beverage.

The tap body has an internal mixing chamber which receives hot water only, cold water only or a mixture of hot and cold water, depending upon the position of angular adjustment of the lever along the arc of movement. The third inlet port communicates with a discharge outlet from the tap body when the lever is adjusted to the arcuate extension, and at the same time communication of the hot and cold water inlets to the mixing chamber is blocked.

In this known design of tap with single operating lever, there is provision of a complicated design of internal valve assembly, which is required selectively to control the supply of (a) hot, cold, hot and cold water mixture, or further liquid e.g. filtered water and (b) the volumes, all under the control of a single operating lever.

The discharge spout has two internal discharge passages, one dedicated to convey hot, cold or mixed hot and cold water, and the other dedicated solely to discharge the further liquid e.g. filtered water.

The second aspect of the invention seeks to simplify the internal design of a water tap body (having three inlet ports and a single operating lever), by excluding requirement to carry out pre-mixing of hot and cold water supplies within a mixing chamber in the tap body, whereby separate flows of hot and cold water can be discharged from the tap body and along respective dedicated spout passages. If mixing is required, this may be obtained by use of a mixer nozzle at the spout outlet. However, for many customers, it may be quite sufficient for initially separate streams or flows of hot and cold water along the discharge spout to come into at least partial mixing contact with each other at or close to the spout outlet.

According to second aspect of the invention there is provided a water tap which comprises: a tap body; first, second and third liquid inlets to the tap body for supplying respectively hot water, cold water and a further liquid to the interior of the tap body; a discharge spout mounted on the tap body and having a discharge outlet at or near

an internal valve assembly in the tap body for selectively controlling the admission of liquids to the interior of the tap body via the first, second and third inlets and the discharge of selected liquid from the tap body to the discharge spout; and, a single operating lever pivotally mounted on the tap body for adjustment movement about a substantially vertical axis and along a predetermined first arc of movement, said lever being coupled with the valve assembly and being operative to selectively control admission of hot water and / or cold water to the tap body via the respective first and second inlets according to the position of adjustment along the arc of movement, and said lever also being movable along an arcuate extension to the arc of movement in which the valve assembly is adjustable to block admission of hot water and cold water and to allow admission only of further liquid via the third inlet: in which the valve assembly defines within the tap body three separate waterways corresponding respectively to the first, second and third inlets, and each dedicated, under adjustment of the valve assembly, to block, or allow flow of hot water only, cold water only, or further liquid only along the respective waterways without any mixing of the liquids within the interior of the tap body.

By provision of three separate waterways within the tap body, and no requirement to carry out pre-mixing of hot and cold water within the tap body, a simple and therefore more reliable (and also inexpensive) design of tap can be obtained.

Preferably, the discharge spout has two dedicated passages, one serving to convey hot water only, and the other serving to convey cold water only, or further liquid e.g. filtered water only.

The first arc of movement may subtend an angle of about 90° about the substantially vertical pivoting axis of the lever, with a mid-position along the arc corresponding to approximately 50:50 ratio of hot / cold water and with one end position corresponding to 100% of one supply and 0% of the other supply, and the other end position corresponding to 100% of the other supply and 0% of the one supply.

The arcuate extension preferably is an extension from the end position of the arc corresponding to maximum cold water supply, and preferably a biassed detent determines this end position and which can only be overcome by deliberate force applied to the lever to move the lever from the arc of movement and onto the arcuate extension. Preferably, the lever is also adjustable about a substantially horizontal axis (throughout the angular adjustment along the arc of movement, or the arcuate extension) in order to control the degree of communication between each inlet port and its respective waterway and thereby control the volumes of liquid flow.

The further liquid supply may be filtered water, and which may be obtained by selective diversion of a cold water supply (feeding to the second cold water inlet to the tap body) through a filter cartridge and then to the third inlet to the tap body. Alternatively, the filtered water may be supplied from other sources.

Preferred embodiments of water tap according to first aspect of the invention will now be described in detail, by way of example only, with reference to the accompanying drawing, in which:

Figure 1 is a schematic drawing of a general type of tap to which the invention may be applied; and

Figure 2 is a perspective illustration of practical embodiment of the invention.

Referring first to Figure 1 of the drawings, a water tap is designated generally by reference 10 and has a tap body 11, separate connections 12, 13, 14 on the tap body 11 for receiving, respectively, supplies of cold water C, filtered water F and hot water H. A common discharge spout 15 is mounted on the tap body 11, and valves are provided to control the supply of hot water H, cold water C and filtered water F from the tap body 11 to the discharge spout 15.

The discharge spout 15 is provided internally with two separate discharge passages only, namely first passage 16 which is dedicated to convey hot water only, and second discharge passage 17 which is dedicated to supply cold water or filtered water. As can be seen, the passages 16 and 17 lead to a common discharge outlet 18 of the spout 15.

The tap body 11 defines a route 19 for hot water only, under control of a hot water control valve 20, and route 19 communicates with the dedicated first discharge passage 16 of the discharge spout 15, and which can therefore discharge hot water only.

The tap body 11 also defines separate incoming routes 21 and 22 for each of the cold water C and the filtered water F. The tap body 11 also defines a common outgoing route 23 for one or the other only of cold water C and filtered water F, and such common outgoing route 23 communicates with the second discharge passage 17, which is dedicated to the common outgoing route 23. A diverter valve 24 is mounted on the tap body 11 and is operative selectively to control the communication of the incoming route 21 for cold water C, or the incoming route 22 for filtered water F, with the common outgoing route 23. According to the operation of the diverter valve, cold water C or filtered water F can be discharged via the outlet 18 of the spout 15, via dedicated second discharge passage 17.

A dual purpose water control valve 25 is provided on the tap body 11, and is operative to control the flow along the common outgoing route 23.

Therefore, in the water tap 10 shown in the drawing, two discharge passages 16, 17 only are provided in the discharge spout 15, and the first passage 16 is dedicated to supply hot water only, whereas the second passage 17 selectively discharges cold water, or filtered water only, under the control of the dual purpose water control valve 25, and depending upon whether the diverter valve 24 communicates the incoming cold water route 21 or the incoming filtered water route 22 with the common outgoing route 23.

The dual purpose water control valve 25 can be quite simply a standard cold water control knob, button or handle, and the diverter valve 24 can be sourced economically by utilising existing technology available in bath taps, or similar.

The diverter valve 24 may be arranged to revert automatically to cold water routing to the common outgoing route (after operation to route filtered water only), and this reversion may be after a predetermined time period, or under spring or other return movement control.

Alternatively, the valves 24, 25 may be integrated in to a single valve assembly, having the dual function of (a) diverting and (b) routing cold water C or filtered water F via the common outgoing route.

Referring now to Figure 2 of the drawings, this shows practical embodiment of the invention, in which the features of the schematically illustrated embodiment of Figure 1 are incorporated into a tap assembly having a common discharge spout for all three flows of water (hot water, cold water and filtered water), and also having a single operating lever.

The embodiment of Figure 2 is designated generally by reference 30, and comprises a tap body 31 which communicates with three separate piped supplies (not shown) of hot water, cold water and filtered water, and which has a common discharge spout 32. A single operating lever 33 is provided, which can be pivoted upwardly to the "on" position, and downwardly to the "off position. Rotation of the lever 33 can be through three separate phases, as shown schematically. The rotation of the lever to the left effects operation of the internal valve assembly (not shown) to route hot water only through the tap body 31 and to be discharged via the outlet 34 of the common discharge spout 32. Rotation of the lever 33 in an anticlockwise direction, as seen in plan view, brings it to a position in which it operates the internal valve assembly so that cold water only is routed through the tap body to be discharged via the outlet spout 34. Further rotation of the lever 33 brings it to a transition point, at which a "detent" is provided, and at such time the internal valve arrangement operates to divert the flow from cold water only to filtered water only, and which is routed through the discharge spout 32 and outlet 34.

This embodiment therefore provides a single lever movement tap, and may have internally a valve which has two or three purposes. The internal valve may comprise a cold / hot mixture arrangement, and progressive movement of the lever, in one direction or the other, alters the relative proportions of hot and cold water to suit requirements. The lever can take-up a position of hot water only, cold water only, or a mixture. Further movement through the cold range reaches the detent position, and thereafter flow is diverted to filtered water only.

Any suitable detent arrangement may be provided, including spring loaded latches etc, and preferably gives a defined "click" to indicate that the diverting point has been reached between cold water only and filtered water only.

The discharge spout 32 may be a single or dual flow spout i.e. with one or more internal passages.

The internal valve arrangement will take any suitable form, e.g. as disclosed above and shown schematically in Figure 1. An alternative arrangement is shown in Figure 2a.

A preferred embodiment of water tap according to second aspect of the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which:

Figure 3 is a diagrammatic view in vertical section of an upper part of a water tap according to the invention, showing an upper part of a tap body, a single operating lever, and a discharge spout having two separate spout flow passages;

Figure 4 is a plan view showing a range of movement of the operating lever; Figure 5 is a diagrammatic view of a water installation incorporating a water tap according to the invention; and,

Figures 6a to d are views showing different operating modes of an internal valve assembly within the tap body, and coupled with the operating lever to be adjusted between the different operating modes illustrated.

Referring now to Figures 3 to 6 of the drawings, a water tap according to the invention is designated generally by reference 100 and comprises a tap body 110, of which the upper part is shown in Figure 3, and having first, second and third inlets to the tap body for supplying respectively hot water, cold water and a further liquid to the interior of the tap body. The first, second and third inlets are designated by references 120, 130 and 140 respectively, and a discharge spout 150 is mounted on the tap body 110 and has two internal spout discharge passages 160 and 170, leading to a common discharge outlet 180

A single operating lever 190 is pivotally mounted on the upper part of the tap body 110, for adjustment movement about a substantially vertical axis 200 and along a predetermined first arc of movement 210, as shown in Figure 4. The lever 190 is coupled with an internal valve assembly 260 (Figure 6) within the tap body (described in more detail below) for selectively controlling the admission of liquids to the interior of the tap body via the first, second and third inlets 120, 130, 140, and also the discharge of selected liquid(s) from the tap body 110 to the discharge spout 150.

During adjustment movement of the lever 190 along the first arc of movement 210, the valve assembly 260 is adjusted to operate selectively to admit hot water and / or cold water to the tap body 110 via the respective first and second inlets 120, 130 according to the position of adjustment of the lever 190 along the arc of movement 210.

As shown in Figure 4, the lever 190 has a mid position 220, in which the mixture proportions of hot and cold water will be approximately 50:50, whereas clockwise movement from the mid position to an end position 230 will progressively increase the proportion of hot water admitted via inlet 120 to the tap body 110, and progressively decrease the proportion of cold water admitted to the interior of the tap body 110 via inlet 130. Similarly, anti-clockwise movement from the mid position towards an opposite end position 240 will progressively increase the proportion of cold water and decrease the proportion of hot water. At each end position, there will be 100% flow of one of the liquids, and 0% admission of the other liquid.

Still referring to Figure 4, the operating lever 190 also is movable along an arcuate extension 250 to the first arc of movement 210, in which the valve assembly 260 is adjusted to block admission of hot water and cold water via inlets 120, 130, and to allow admission only of further liquid via the third inlet 140.

Although not shown in detail, the interior of the tap body has dedicated waterways corresponding to each of the inlets 120, 130, 140, and under adjustment of the valve assembly, flow of hot water only, cold water only, or further liquid only along the respective waterways is blocked, or allowed, without any mixing of the liquids within the interior of the tap body.

The separate waterways lead to the inner end of discharge spout 150, and the routing of the waterways is such that the waterway Wh for hot water only leads to the spout discharge passage 160, whereas the waterways dedicated to cold water W_c and further liquid W_f (filtered or "pure" water) both lead to the spout discharge passage 170.

When the valve assembly is adjusted to end position 230 of lever 190, hot water only will be admitted to the tap body 110 via hot water inlet 120, and is then routed along a dedicated waterway W_h leading to spout passage 160, so that hot water H only is routed along the spout 150 and is discharged via outlet 180. When the lever 190 is adjusted to end position 240, cold water only is admitted to the tap body 110 via cold water inlet 130, and is then routed via waterway W_c for cold water which leads to entry end of spout passage 170, so that cold water C only flows along passage 170 to be discharged via outlet 180.

In the event that the lever takes-up a position intermediate the end positions 230 and 240, relative proportions of hot and cold water will be admitted to the tap body 110, and each proportion of hot water H and cold water C is then routed along its own dedicated waterway W_h and W_c, for independent passage along separate spout passages 160, 170, and then are discharged together via outlet 180, which may incorporate a mixer nozzle if required, if mixing of hot and cold is required.

When the operating lever 190 is rotated anti-clockwise beyond the end position 240 of the first arc of movement 210, the valve assembly is adjusted so as to block any admission of hot water via inlet 120 or cold water via inlet 130, and then allows admission of filtered water F via inlet 140, which communicates with dedicated internal waterway W_f which leads to the entry end of spout passage 170, so that filtered water F only flows along discharge spout 150, to be discharged via outlet 180.

The first arc of movement 210 subtends an angle of about 90° about the pivoting axis 200 of the lever 190, and the arcuate extension 250 extends beyond the cold water only end position 240 through an angle of approximately 25%. A biassed detent e.g. a spring-loaded ball or the like may be provided, to determine the end position 240, and which can only be overcome by deliberate force applied to the lever 190 to move the lever from the first arc of movement 210 and onto the arcuate extension 250.

The lever 190 is also adjustable about a substantially horizontal axis, as shown in Figure 3, with a lower position of the lever 190 being an "off position for all liquids supplied to the tap body, and the dashed outline showing an upper adjusted position of maximum volume of flow of liquid, of which the proportions will be dependent upon the position of the lever 190 along the path of movement shown in Figure 2.

Figure 5 shows water tap 100 incorporated in a water installation, preferably provided for a kitchen sink. Alternatively, the water tap 100 may be installed in / on a basin in a bathroom; or it may be mounted on a work surface. Cold water is supplied to the tap 100 via supply pipe 260, hot water via supply pipe 270, and filtered or purified water via supply pipe 280. A diverter arrangement (not described in detail) may divert cold water supply via a water filter cartridge 290, and the admission of cold water, hot water, and filtered water is then controlled by operation of the lever 190, as described above.

Figures 6a to d show different operating positions taken-up by the relatively slidable portions of an internal valve assembly 360, of which the movable portion is coupled with lever 190 to provide the required control of admission of: hot water only; cold water only; variable proportions of hot and cold water; and filtered water. A lower portion of the valve assembly is provided with inlets corresponding to inlets 120, 130, 140, and the upper movable portion of the valve assembly blocks or allows partial or total communication with the respective waterway W_h, W_c and W_f, according to the angle of adjustment of lever 190 about the axis 200. Upward adjustment of lever 190 about the horizontal axis increases the area of communication between each inlet and its respective waterway, to increase the volume of flow.

Figure 6a shows in the left hand view adjustment of the valve assembly 360 to a position in which it is ready to receive supplies of hot and cold water via the inlets 120 and 130, but in which the tap 100 is effectively "switched-off, by reason of the lever 190 being in the lower closed position. The right hand illustration of Figure 6a shows the valve assembly adjusted to an "open" position in which both hot and cold water supplies are admitted to the tap body via the respective inlets, and then routed along the dedicated waterways without any mixing of the flows of hot and cold water internally of the tap body.

Similarly, Figure 6b shows in the left hand view the valve assembly adjusted to a position to receive hot water supply only, but with the tap switched off. Figure 6b in the right hand view shows the valve assembly adjusted to receive hot water only.

Figure 6c shows in the left hand view the positions of the valve assembly corresponding to being ready to receive cold water only, but with the tap switched off, whereas the right hand view shows the adjustment of the valve components to an open position for cold only.

Finally, Figure 6d shows the valve assembly components adjusted to a position in which admission of cold water and hot water is blocked, and only filtered water is admitted via filtered water inlet 140 and then passes to dedicated waterway W_f, and leading to entry end of discharge passage 170 in spout 150.

A preferred additional option feature to the tap embodiments of the invention disclosed herein include provision of a separate discharge attachment e.g. a spray attachment. This may form part of the tap assembly, or may be sited remotely from the tap assembly. The attachment may be incorporated in the discharge spout e.g. as a pull-out spray unit.

This separate discharge attachment can discharge different types of water flow in the same way as described for the illustrated embodiments. The routing of the water flows to the separate discharge attachment will be obtained by a suitable valve management unit or assembly (valve; diverter or the like).

Claims

CLALMS

1. A water tap (10) having a tap body (11,31), separate connections (12, 13, 14) on the tap body (11,31) for receiving supplies of hot water H, cold water C and filtered water F, a common discharge spout (15,32) mounted on the tap body (11), and valve means (20, 24, 25) for controlling the supply of hot water H, cold water C and filtered water F from the tap body (11,31) to the discharge spout (15,32), in which: the discharge spout (15,32) is provided internally with two separate discharge passages (16, 17) only which lead to a common discharge outlet (18) of the spout (15,32); the tap body (11) defines a route (19) for hot water only which communicates with a dedicated first one (16) of the two separate discharge passages in the discharge spout (15,32) and which can therefore discharge hot water H only; the tap body (11,31) also defines a separate incoming route (21, 22) for each of the cold water C and the filtered water F, and a common outgoing route (23) for one or the other only of cold water C and filtered water F and such common outgoing route (23) communicating with a second of the two separate discharge passages (17) and which is dedicated to said common outgoing route (23);

The valve means includes (24, 25) when is mounted on or in the tap body (11) and is operative selectively to divert the communication of the incoming route (21) for cold water C, or the incoming route (22) for filtered water F, with the common outgoing route (23) depending upon whether cold water discharge or filtered water discharge is required, and to control the flow along said common outgoing route (23); and a single lever 33 is mounted on the tap body (31), to control the operation of the valve means (20,24, 25).

2. A water tap (100) which comprises: a tap body (110); first, second and third inlets (120, 130, 140) for supplying respectively hot water H, cold water C and a further liquid F to the interior of the tap body (110); a discharge spout (150) mounted on the tap body (110) and having a discharge outlet (180) at or near its free end; an internal valve assembly (360) in the tap body (110) for selectively controlling the admission of liquids to the interior of the tap body (110) via the first, second and third inlets (120, 130, 140) and the discharge of selected liquid(s) from the tap body to the discharge spout (150); and, a single operating lever (190) pivotally mounted on the tap body (110) for adjustment movement about a substantially vertical axis (200) and along a predetermined first arc of movement (210), said lever (190) being coupled with the valve assembly (360) and being operative to selectively admit hot water H and / or cold water C to the tap body (110) via the respective first and second inlets (120, 130) according to the position of adjustment along the arc of movement (210), said lever (190) also being movable along an arcuate extension (250) to the arc of movement (210) in which the valve assembly (360) is adjusted to block admission of hot water H and cold water C and to allow admission only of further liquid F via the third inlet (140): in which the valve assembly (360) defines within the tap body (110) three separate waterways W_h, W_c, W_f corresponding to the first, second and third inlets (120, 130, 140), and each dedicated, under adjustment of the valve assembly (360), to block or to allow flow of hot water H only, cold water C only, or further liquid F only along the respective waterways W_h, W_c, W_f and without any mixing of the liquids within the interior of the tap body (110).

3. A water tap according to claim 2, in which the discharge spout (150) has two dedicated passages (160, 170), of which first passage (160) serves to convey hot water H only, and second passage (170) serves to convey cold water C only, or further liquid F only.

4. A water tap according to claim 2 or 3, in which the arc of movement (210) subtends an angle of about 90° about the pivot axis (200) of the lever (190), and the arcuate extension (250) forms a prolongation of the arc of movement (210), leading from the 100% cold water only end position (240) on the arc of movement (210).

5. A water tap according to claim 4, in which a biassed detent determines the cold water end position (240), and which can be overcome by deliberate force applied to the lever (190) to move the lever (190) from the arc of movement (210) and onto the arcuate extension (250).

6. A water tap according to any one of claims 2 to 5, in which the lever (190) is also adjustable about a substantially horizontal axis, throughout the angular adjustment along the arc of movement (210) and the arcuate extension (250), in order to control the extent of communication between each inlet (120, 130, 140) and its respective waterway W_h, W_c, W_f and thereby control the volume of liquid flow.