GB2061874A - Dispensing liquids from containers - Google Patents

Abstract

An installation for dispensing liquid from a container 48, comprising a dispensing head 10 fitted to the container and to a source of pressurising gas, the head having a valve member movable between a "dispensing" position in which liquid from the container 48 can flow under pressure of the gas to the dispensing tap 52 and "rinsing" position in which rinsing water can flow from a source 60 through the head 10 to the tap 62, the valve member being movable in dependence upon the operation of a control device 200. To ensure that the dispensing tap 52 is left open when the control device is set to the "rinsing" mode and that the device is automatically reset to "dispensing" when the tap 52 is closed, the control device 200 is adapted to sense the pressure of liquid in the pipe 50 connecting the dispensing head 10 to the dispensing tap 52 and to cause the valve member to move to or remain in the "dispensing" position when the pressure of liquid in the pipe indicates that the dispensing tap is closed. <IMAGE>

Description

SPECIFICATION Installations for dispensing liquids from containers This invention relates to installations for dispensing liquids from containers.

The invention is particularly, though not exclusively, concerned with installations for dispensing beer, lager or soft drinks from a keg under pressure of carbon dioxide gas supplied through a dispensing head mounted on the keg, the dispensing head being connected to a pipe which feeds the beer or other liquid to a dispensing tap. Such installations are widely used, for example in public houses and restaurants.

In German Offenlegungsschrift (DE) 28 51 453 there is described an installation for dispensing liquid from a container, comprising a dispensing head adapted to be fitted to the container and to a source of pressurizing gas to enable liquid to be dispensed from the container under pressure of gas supplied to the container through the dispensing head, a dispensing tap connected to the dispensing head through a pipe, a source of rinsing fluid connected to the dispensing head, the dispensing head having a valve member movable between a "dispensing" position in which liquid from the container can flow to the dispensing tap and a "rinsing" position in which rinsing fluid can flow through the dispensing head to the dispensing tap, the valve member being movable between the "dispensing" and "rinsing" positions in dependence upon the operation of a control device positioned near the dispensing tap.

In operation of such an installation, it is necessary for the valve member of the dispensing head to be put in the "rinsing" position before the head is transferred from one container to another, so that the installation has to be placed in the rinsing mode at each change of container. However, adequate rinsing cannot take place if the dispensing tap is left closed during the change of container.

It is therefore possible for the described installation to be operated without effective rinsing of the dispensing tap and associated pipework, even though the installation makes rinsing a simple operation.

It is an object of the present invention to provide an improved installation for dispensing liquids from containers, which ensures that the dispensing tap and associated pipework are rinsed at least when ever the dispensing head is transferred from one container to another.

This invention consists in an installation for dispensing liquid from a container, comprising a dispensing head adapted to be fitted to the container and to a source of pressurising gas to enable liquid to be dispensed from the container under pressure of gas supplied to the container through the dispensing head, a dispensing tap connected to the dispensing head through a pipe, a source of rinsing fluid connected to the dispensing head, the dispensing head having a valve member movable between a "dispensing" position in which liquid from the container can flow to the dispensing tap and a "rinsing" position in which rinsing fluid can flow through the dispensing head to the dispensing tap, the valve member being movable between the "dispensing" and "rinsing" positions in dependence upon the operation of a control device positioned near the dispensing tap, in which the control device is adapted to sense the pressure of liquid in the pipe connecting the dispensing head to the dispensing tap and to cause the valve member of the dispensing head to move to or remain in the "dispensing" position when the pressure of liquid in the pipe indicates that the dispensing tap is closed.

In operation of such an installation, the system cannot remain in the "rinsing" mode unless the dispensing tap is left open. It is therefore necessary to leave the tap open whilst the dispensing head is being transferred from one keg to another, thus ensuring that the dispensing tap and pipe are rinsed at least at each change of keg.

The invention is particularly applicable to an installation employing a dispensing head as described in the said German Offenlegungsschrift 28 514 53, in which the valve member of the dispensing head is movable by means of a piston movable in a cylinder of the dispensing head response to the pressure of rinsing fluid applied to a control inlet in the dispensing head, and the control device consists of a control valve through which rinsing fluid can be supplied to the control inlet.In this case, the control valve, in accordance with the present invention, may comprise a valve body, a valve member movable freely in the body between a "dispensing" position in which rinsing fluid can flow from the source through the control valve to the control inlet of the dispensing head so that the valve member of the dispensing head is held in the "dispensing" position, and a second position in which the valve member of the dispensing head is moved to its "rinsing" position, the control valve further including a manually operable actuating member operation of which moves the valve member of the control valve to its "rinsing" position, a chamber in the valve body in communication with the pipe connecting the dispensing head to the dispensing tap, and a piston movable in the chamber and co-operating with the valve member so that when the dispensing tap is closed the pressure of liquid in the chamber acting against the piston effects movement of the valve member to its "dispensing" position.

Suitably the chamber in the body of the control valve has an inlet and an outlet connected to the said pipe, so that liquid flowing through the pipe flows also through the chamber.

Preferably, the dispensing head has a second control inlet, supply of rinsing fluid to the second control inlet causing the valve member to move to the "rinsing" position, the water supplied to the second control inlet flowing to the outlet of the dispensing head when the valve member is in the "rinsing" position, and the control valve is so arranged that, when the valve member of the control valve is in its "rinsing" position, rinsing fluid flows through the control valve to the second control inlet of the dispensing head.

Advantageously, the piston is fixed to or integral with the valve member of the control valve.

The passages in the valve member of the control valve may be so arranged that in the dispensing position the pressure of the rinsing fluid does not urge the valve member towards the tapping position, so that the manual force necessary to move the valve member to the rinsing position need only be high enough to overcome the pressure against the piston in the control valve of the fluid being dispensed.

The valve member can therefore be moved easily, even when the rinsing fluid pressure is high.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic diagram of an installation for dispensing beer-from a keg, in accordance with the invention, Figure 2 is a vertical section through a dispensing head forming part of the installation of Fig. 1, the left-hand and right hand halves of the Figure showing a valve member of the head in lowermost and uppermost positions respectively, Figure 3 is a section through a control valve forming part of the installation of Fig. 1, showing the valve in the "dispensing" position, Figure 4 is a section similar to that of Fig.

3, showing the valve in the "rinsing" position, Figure 5 shows a modified form of control valve according to the invention, and Figure 6 shows a control valve similar to that of Fig. 5, but with a further modification of its actuating member.

Referring to Fig. 1, an installation for dispensing beer from a keg 48, consists of a dispensing head 10 fitted to the keg 48 and connected to a dispensing head 52 through a beer pipe 50, a cylinder 54 of compressed carbon dioxide gas connected through a pressure regulator 55 and a pipe 56 to the dispensing head 10, and a source of rinsing water (for example mains water) connected through a stopcocln 60 and piping 106 to a control valve 200. The control valve 200 is also connected through water pipes 1 02 and 104 to the dispensing head 1 0. The beer pipe 50 is connected to the control valve 200, as described below, and may also pass through a chiller (not shown) in the usual way.

Referring to Fig. 2 the dispensing head 10 comprises an adaptor 1 2 for connection to the tapping hole of a keg, a body 1 4 fixed to the adaptor and surmounted by a cylinder 16, and a valve member 1 8 vertically movable relative to the adaptor 12, body 1 4 and cylinder 16, the valve member having a longitudinally extending channel 20.

The adaptor 1 2 is shaped to fit onto the mouth of a keg, and the lower part of the valve member 1 8 is shaped to engage the valve plunger forming part of the keg, when the valve member is in its lowermost position, so that beer from the keg can flow through the channel 20 of the valve member. The various keg tapping systems in use, and the shape of the adaptor and lower part of the valve member necessary for use with each system, will be well known to those skilled in the art.

The adaptor 1 2 is formed in the usual way with a lateral inlet 22 to which can be connected a pipe supplying carbon dioxide gas under pressure. When the valve member 1 8 is in its lowermost position (as shown on the left-hand side of (Fig. 2) the inlet 22 is, in use, in communication with the interior of the keg, whilst when the valve member is in its uppermost postion (as shown on the righthand side of Fig. 2) the inlet 22 is closed by engagement of the valve member with O-ring 26.

Fixed to the valve member 20 is a piston 28 which moves in the cylinder 16, engagement of the piston with the top and bottom internal faces of the cylinder defining the uppermost and lowermost positions of the valve member. The upper part of oC- the valve member 1 8 extending above the piston 1 6 projects into a cylindrical cavity 482 in a neck 481 fixed to the cylinder 16. The upper cavity of the cylinder 1 6 is sealed from the cavity 482 means of two O-rings 483 positioned between the neck 481 and valve member 18.

At the upper end of the neck 481 is an outlet 48 to which can be connected a beer pipe 50 leading to a dispensing tap 52 (Fig. 1).

A control inlet 90, which as described below is to be connected to a source of rinsing water, is formed in the cylinder 1 6 and communicates through channel 92 with the interior of the cylinder 1 6 above the piston 28. A second rinsing inlet 94 opens into the cylinder 1 6 below the piston 28. When the valve member 1 8 is in its uppermost position as shown on the right-hand side of Fig. 2 the interior of cylinder 1 6 below the piston 28 is in communication with the central channel 20 of the valve member 1 8 through bores 96 in the valve member, so that rinsing water supplied to the inlet 94 can flow into the channel 20.When the valve member 18 is in its lowermost position as shown on the left-hand side of Fig. 2 the bore 96 is closed and water is prevented from leaking into channel 20 by an O-ring 98. A non-return valve member 401 is secured to the lower end of a vertical stem 402, which is fixed at its upper end to the neck 481 by a member 403 suitably perforated so as not to obstruct the flow of liquid to the outlet 48. The non-return valve member 402 is positioned so as to engage a valve seat 42 on the valve member 1 8 when the latter is in its uppermost position, to prevent rinsing water entering the keg. There is thus a positive shut-off communication between the interior of valve member 1 8 and the keg when the valve member is in its uppermost position.

In operation, when rinsing water is supplied to inlet 94 through control valve 200, as described below, the piston 28 is lifted by the water pressure to its uppermost position. The gas inlet 22 is thus closed, and the interior of the keg disconnected from the channel 20 of valve member 18 by non-return valve 401.

Rinsing water flows from inlet 94 through the cylinder 1 6 and bores 96 to the channel 20, from where it can flow through outlet 48 and the beer pipe 50 to the dispensing head 52.

When the supply of rinsing water to inlet 94 is cut off, and water is supplied to inlet 90.

the water pressure acting on piston 28 moves valve member 1 8 to its lowermost position, so that gas can flow through the inlet 22 to the interior of the keg, the spear valve of the keg being opened by engagement with the lower end of valve member 1 8. At the same time valve 401 is opened so that beer can flow from the keg through channel 22 and outlet 48 to the beer pipe 50 and dispensing tap 52.

As shown in Fig. 3, the control valve 200 comprises a body 202. A valve member 306 slides in an axial bore 204 in body 200. The valve member 306 has two transverse bores 208 and 212. Bore 208 is in the communication with an axially extending bore 310 which communicates with a further transverse bore 312. Bore 212 similarly communicates with an axial bore 214 which extends, in the opposite direction, to one end 21 8 of the valve member 306. The valve body 202 has a rinsing water inlet 220 which is connected to the water supply pipe 106 (Fig. 1) and which includes a passage 222 opening into the axial bore 204 in the body 202.On the same side as the inlet 220 the body 202 is formed with two outlets 224 and 230, which are connected respectively to the two pipes 102 and 104 leading to the water inlets 90 and 94 of the dispensing head 1 0. The outlet 224 is connected by a passage 226 to an annular recess 328 in the wall of the axial bore 204. The annular recess 328 extends axially to that the transverse bore 31 2 in valve member 306 opens into the recess 238 in both the "dispensing" position (Fig. 3) and "rinsing" position (Fig. 4), so that outlet 224 is always in communication through bore 31 2 with the axial bore 310 leading to transverse bore 208 in the valve member.The outlet 230 is connected by a passage 232 to a larger diameter portion 234 of the axial bore 204 in which the end 218 of the valve member 306 moves, so that the outlet 230 is always in communication with the axial bore 214 leading to the transverse bore 21 2 in the valve member.

In the side opposite the inlet 220 and outlets 224 and 230, the valve body 202 is formed with a drain outlet 240, which is connected to two passages 236 and 238 opening into the axial bore 204 at locations which are symmetrically disposed, as measured in the axial direction, on either side of the water inlet passage 222. The drain outlet 240 is connected through a pipe 241 (Fig. 1) to a suitable drain.

The various passages in the body 202 and the transverse bores 208 and 21 2 in the valve member 306 are so arranged that in the "dispensing" position of the valve member, as shown in Fig. 3, the transverse bore 208 is in communication with the water inlet passage 222 and the bore 212 is in communication with the passage 238 leading to the drain outlet 240, whereas in the "rinsing" position of the valve member, as shown in Fig. 4, the transverse bore 208 is in communication with the passage 236 leading to the drain outlet and the transverse bore 21 2 is in communication with the water inlet passage 222. A series of O-rings 242 are provided in annular recesses in the body to prevent leakage of water between the valve body 202 and valve member 306.A piston 362 is fixed to one end of the valve member 306 so as to be movable with the valve member.

At one end the valve 200 is provided with a manually-operated actuating member in the form of an actuating member 344 slidable in a collar 346 mounted in the mouth of the larger diameter portion 234 of the bore 204.

The member 244 is slidable between an outer position (Fig. 3) defined by engagement of a ring 348 on the member 344 with the inner end of the collar 346 and an inner position (Fig. 4), so that in moving from the outer to the inner position the actuating member 344 engages the valve member 306 and moves it from the "dispensing" position (Fig. 3) to the "rinsing" position (Fig. 4). The actuating member 344 is formed at its outer end with a push-button 350 by means of which it can be moved from its outer to its inner position. An annular guard 352 integral with the collar 246 surrounds the push-button 350 to pre vent it being inadvertently depressed.

At the end of the body 202 opposite the push-button 350 is a chamber 256 which is in communication with an inlet 258 and outlet 260. The inlet 258 and outlet 260 are connected to the beer line 50 so that all the liquid flowing through the beer line 50 to the dispensing tap 52 passes through the chamber 256. The piston 362 fixed to valve member 306 moves within the chamber 256, the innermost position of the piston being defined by engagement of the piston with a support member 370. An O-ring 364 fitting into an annular recess in the piston 362 prevents leakage of beer or water past the piston. An outlet 365 in body 202 allows the escape of air from beneath piston 362 as it moves to the "dispensing position".

In operation of the described installation, the valve member 306 is normally in the "dispensing" position, i.e. the position nearest the push-button 350 as shown in Fig. 3.

The water supply 60 is therefore connected through inlet 220, and passages 208 and 310 in valve member 306 to the outlet 224 and from there, through pipe 102 to the control inlet 90 of the dispensing head 1 0.

The water pressure therefore acts on piston 28 (Fig. 2) to hold the valve member 1 8 of the dispensing head 10 in the lowermost position. Beer can therefore flow, under pressure of carbon dioxide gas supplied through inlet 22, to the beer pipe 50 and dispensing tap 52. When the beer pipe 50 and tap 52 are to be rinsed, tap 52 is opened and the push-button 350 of control valve 200 is depressed. Depression of the push-button moves the valve member 306 and its piston 362 to the "rinsing" position shown in Fig. 4. The water supply is thereby disconnected from outlet 224 of control valve 200 and is connected, through passages 212 and 214 of the valve member 306 to the water outlet 230.

Rinsing water therefore flows through line 104 to the inlet 94 of dispensing head 10, and the water pressure acting on piston 28 moves the valve member 18 of the dispensing head 10 to its uppermost position. The supply of beer from the keg is therefore shut off, as described above, and rinsing water flows through the passage 20 in the valve member 1 8 and to the beer pipe 50 and dispensing tap 52. As the piston 28 moves to its uppermost position, the water in the cylinder 1 6 above the piston is vented through the inlet 90, which is in communication, through pipe 102, outlet 224 and passages 312, 310 and 208 of the valve member 306, with passage 236 and outlet 240 leading to the drain.

As long as the dispensing tap 52 remains open, the pressure in the chamber 256 of control valve 200 remains low, so that there are no forces tending to move the piston 362 and valve member 306 of the control valve towards the "dispensing" position. The valve member 306 therefore remains in the "rinsing" position (Fig. 4), even when the pushbutton 350 is released. It is therefore necessary only to depress the push-button 350 to initiate the rinsing, after which the button can be immediately released. To terminate the rinsing action, the dispensing tap 52 is closed. The pressure in chamber 256 therefore rises towards that of the water supply, and the pressure moves the piston 362 and valve member 306 to the "dispensing" position shown in Fig. 3.Water pressure is thus again applied to inlet 90 of the dispensing head 10, moving the valve member 1 8 of the dispensing head 10 back to its lowermost position. The inlet 94 of the dispensing head is connected through pipe 104, inlet 230 and passages 214, 212 and 238 and outlet 240 to the drain, so that the liquid below piston 28 can be vented as the valve member moves to the lowermost position.

The control valve thus ensures that the system automatically returns to the "dispensing" mode when the dispensing tap 52 is closed. To return to dispensing beer, it is necessarily only to open the dispensing tap again and to initially draw off and discard the rinsing water remaining in the beer pipe.

It will be apparent that if the push-button 350 is depressed whilst the dispensing tap 52 remains closed, the piston 362 of the control valve 200 will be moved against the pressure of beer (or rinsing water) in the chamber 256, so that the piston 362 will move back to the "dispensing" position as soon as the button 350 is released. The system therefore cannot remain in the "rinsing" mode unless the dispensing tap 52 is open. When it is desired to transfer the dispensing head 10 from one keg to another, for example from an empty keg to a full one, it is necessary for the system to be in the "rinsing" mode, so that the valve member 1 8 of the dispensing head is in its uppermost position and disengaged from the spear valve of the keg.It is therefore necessary to open the dispensing tap, press the button 350 to initiate rinsing and to leave the system in the rinsing mode until the dispensing head has been fitted to the new keg. Thus, the described installation, as well as facilitating routine rinsing of the beer pipe and dispensing tap, ensures that the rinsing is carried out at least at every change of keg.

In the "dispensing" position shown in Fig.

3, the rinsing water from inlet 220 occupies the axial bore 310 in the valve member 306 and the annular recess 238 surrounding the valve member 360, which is of uniform diameter. It will be apparent therefore that the pressure of the rinsing water exerts no axial force on the valve member 306. The force required to be exerted on push-button 350 to move the valve member 306 to the rinsing position has therefore to overcome only the pressure of the beer in cavity 256 against piston 362. The push-button 350 can be easily moved, even if the pressure of the rinsing water is very high.

Fig. 5 shows a second embodiment of the control valve of the invention, in which the valve member comprises a valve spool 206 and a separate piston 262. The valve spool 206 is similar to the lower part of the valve member 306 of the first embodintent as seen in Figs. 3 and 4, having similar passages 208, 212 and 214. A passage 210 leads from the passage 208 to the end of valve spool 206. The piston 262, which moves in chamber 256 as in the first embodiment, has a rod 264 which extends through a bore in a support member 270 fixed to the valve body and emerges into the enlarged portion 228 of axial bore 204, so that the end of the rod 264 can engage the end 21 6 of valve spool 206.The rod 264 is formed with a passage 266 extending from its end to radial bores 268, so that engagement of the rod 264 with valve spool 206 does not impede the flow of rinsing water from passage 210 in the valve spool.

At one end the valve 200 is provided with a manually-operated actuating member in the form of an actuating member 244 slidable in a collar 246 mounted in the mouth of the larger diameter portion 234 of the bore 204.

The member 244 is slidable between an outer position (Fig. 5) defined by engagement of a flange 248 on the member 244 with the inner end of the collar 246 and an inner position (not shown), so that in moving from the outer to the inner position the actuating member 244 engages the valve spool 206 and moves it from the "dispensing" position (Fig. 5) to the "rinsing" position (Fig. 6). The actuating member 244 can be moved from the outer to the inner position by means of a push-button in the form of a rubber disc 250, which is joined by a flexible web portion 252 to an annular support portion 254 clamped between the collar 246 and a retaining member 256 screwed onto the collar.

Operation of the embodiment of Fig. 5 is similar to that of the first embodiment, the valve spool 206 being moved to the "rinsing" position by operation of the button 250, and the piston 262 being moved by fluid pressure into engagement with the valve spool 206, to return it to the "dispensing" position, when the dispensing tap 52 is closed.

Fig. 6 shows a valve spool 206 and piston 262 as in Fig. 5, but in the "rinsing" position. Fig. 6 also shows a further alternative form of actuating member comprising a push button consisting of a block 280 slidable in the enlarged portion 234 of axial bore 204, so that it can engage and move the valve spool 206. The block 280 has a radial bore 282 which, when the button is in its outer position as shown in Fig. 6, is aligned with the passage 232 leading to water outlet 230.

The passage 282 leads to a chamber 284 in the block 280, from which further passage 286 opens into the portion 234 of axial bore 204. Thus, when valve spool 206 is in the rinsing position, rinsing water can flow through passage 286, chamber 284 and passage 282 to the outlet 230, the block 280 being held in its outer position by the water pressure. The chamber 286 is closed by a removable cap 288, which may be of transparent plastics. This enables a detergent to be introduced into the rinsing water, for example in the form of a tablet of solid detergent placed in the chamber 284, or a metered volume of liquid detergent injected into the chamber from a suitable dispensing device.

The control valve could be further modified, for example by having a further passage extending through the body 202 to the portion 234 of bore 204, through which liquid detergent could be introduced to the rinsing water.

The actuating members shown in Figs. 5 and 6 could also of course be used in the embodiment of Figs. 3 and 4, in the place of the push button 350.

It will be appreciated that other modifications could be made to the described embodiments. For example, in the embodiment of Figs. 3 and 4, piston 326 could be formed integrally with the valve member 306. Other dispensing heads could be used, such as those described in the above-mentioned Offenlegungsschrift 28 51 453. To enable the valve member 1 8 of the dispensing head to be move to the rinsing position (to allow the head to be removed from a keg) in the event of a temporary interruption of loss of pressure in the water supply, arrangements could be made for pressurised gas to be supplied to control inlet 90 in place of the water supply.

Claims (11)

1. An installation for dispensing liquid from a container, comprising a dispensing head adapted to be fitted to the container and to a source or pressuring gas to enable liquid to be dispensed from the container under pressure of gas supplied to the container through the dispensing head, a dispensing tap connected to the dispensing head through a pipe, a source of rinsing fluid connected to the dispensing head, the dispensing head having a valve member movable between a "dispensing" position in which liquid from the container can flow to the dispensing tap and a "rinsing" position in which rinsing fluid can flow through the dispensing head to the dispensing tap, the valve member being movable between the "dispensing" and "rinsing" positions in dependence upon the operation of a control device postioned near the dispensing tap, characterised in that the control device is adapted to sense the pressure of liquid in the pipe connecting the dispensing head to the dispensing tap and to cause the valve member of the dispensing head to move to or remain in the "dispensing" position when the pres sure of liquid in the pipe indicates that the dispensing tap is closed.

2. An installation as claimed in claim 1, in which the valve member of the dispensing head is movable by means of a piston mov able in a cylinder of the dispensing head in response to the pressure of- rinsing fluid ap plied to a control inlet in the dispensing head, characterised in that the control device consists of a control valve through which rinsing fluid can be supplied to the control inlet, the control valve comprising a valve body, a valve member movable in the body between a "dis pensing" position in which rinsing fluid can flow from the source through the control valve to the control inlet of the dispensing head so that the valve member of the dispensing head is held in the "dispensing" position, and a second position in which the valve member of the dispensing head is moved to its "rinsing" position, the control valve further including a manually operable actuating member operation of which moves the valve member of the control valve to its "rinsing" position, a chamber in the valve body in communication with the pipe connecting the dispensing head to the dispensing tap, and a piston movable in the chamber and co-operating with the valve member so that when the dispensing tap is closed the pressure of liquid in the chamber acting against the piston effects movement of the valve member to its "dispensing" position.

3. An installation as claimed in claim 2, characterised in that the piston is fixed to or formed integrally with the valve member.

4. An installation as claimed in claim 2, characterised in that the piston is axially movable independently of the valve member and is arranged to engage the valve member to move it to the "dispensing" position on movement of the piston under pressure of liquid in the chamber.

5. An installation as claimed in any one of claims 2 to 4, characterised in that the chamber in the body of the control valve has an inlet and an outlet connected to the said pipe, so that liquid flowing through the pipe flows also through the chamber.

6. An installation as claimed in any one of claims 2 to 5, in which the dispensing head has a second control inlet, supply of rinsing fluid to the second control inlet causing the valve member of the dispensing head to move to the rinsing position, the water supplied to the second control inlet flowing to the outlet of the dispensing head when the valve member of the dispensing head is in the "rinsing" position, characterised in that the control valve is so arranged that, when the valve member of the control valve is in its "rinsing" position, rinsing fluid flows through the control valve to the second control inlet of the dispensing head.

7. An installation as claimed in claim 6, characterised in that the valve member comprises a valve spool movable in a bore in the valve body, in that the valve body first and second ports opening into the bore and connected respectively to the first and second control inlets of the dispensing head, and a third port opening into the said bore and connected to the source of rinsing fluid, and in that the valve spool has a first channel which, in the "dispensing" position of the valve member, connects the first port to the third port, and a second channel which, when the valve member is in the "rinsing" position connects the second port to the third port.

8. An installation as claimed in claim 7, characterised in that the valve body has a fourth port connected to a drain, and in that the channels in the valve spool are so arranged that, in the "dispensing" position of the valve member, the second part is connected to the fourth port and, in the "rinsing" position of the valve member, the first port is connected to the fourth port.

9. An installation as claimed in any preceding claim, characterised in that the manually operable actuating member comprises a push-button movable in the valve body and position so that when the button is depressed it engages the valve member to push it to its "rinsing" position.

10. An installation as claimed in claim 9, characterised in that the push button has a chamber in communication with a passage in the control valve through which rinsing fluid flows to the dispensing head, through which detergent can be added to the rinsing fluid.

11. An installation for dispensing liquid from a container, constructed, arranged and adapted to operate substantially as described with reference to, and as shown in, Figs. 1, 3 and 4, or Figs. 1 and 5, or Figs. 1 and 6 of the accompanying drawings.