GB2056621A

GB2056621A - Multi-way valve assembly

Info

Publication number: GB2056621A
Application number: GB8021965A
Authority: GB
Original assignee: Thomson-Brandt SA
Current assignee: Thomson-Brandt SA
Priority date: 1979-07-06
Filing date: 1980-07-04
Publication date: 1981-03-18
Also published as: EP0022414B1; DE3066960D1; BR8004200A; IN155927B; AU6015680A; AU537350B2; GB2056621B; YU41721B; JPH0251638B2; FR2461054B1; FR2461054A1; JPS5618897A; ES493125A0; EP0022414A1; YU172080A; ES8106777A1; ATE6679T1

Abstract

A multiple liquid dispenser (5) comprises a single solenoid valve for controlling the intake of liquid; (n-1) liquid guide devices (11) connected in cascade as the connecting system between the single inlet (7) and the n outlets, the guide devices each having three ways (14, 15, 16) and comprising a float valve (12) which is movable to control flow from the way (16) to each of ways (14, 15), the valves being sequentially actuated by the incoming liquid upon repeated opening and closing of the solenoid valve for fixed periods, a hole (25) of predetermined size for connection to atmosphere being formed in the path of the incoming liquid downstream of the valve seat defined between each inlet way (16) and the associated way (15). During operation each float valve (12) is held in turn against the seats surrounding the ways (15), (14) by suction created by downstream negative pressures. <IMAGE>

Description

1 GB 2 056 621 A 1 SPECIFICATION c A multiple liquid supply assembly and

apparatus incorporating it The invention relates to a multiple liquid supply assembly and a device such as a washing machine, equipped with the assembly.

A large number of industrial or domestic devices require a supply of liquid to one or more of their components. In a washing machine, for example, the adjuvants used are frequently disposed in separate vessels and successively introduced into the machine tub during operation, frequently by admit ting a liquid (e.g. water) into the corresponding vessel so as to drive out the products. A number of methods of multiple liquid supply have already been proposed. One method is to connect each vessel individually to a source of liquid via a tap or solenoid valve. This method has the advantage of being simple but is laborious, since the number of taps or valves required is as great as the number of separate vessels. Another method is to connect the various vessels to a source of liquid via a piston and slide-valve tubular distributor. The two ends of the tubular distributor are connected to the source of liquid via two respective solenoid valves or one double solenoid valve, and are also connected to the vessel at various places on its body. A piston and slide valve is pushed into one of its positions by the 95 incoming liquid, depending on whether the two solenoid valves or the double solenoid valve is or are opened separately in alternation or simultaneously, after which the piston and slide valve connects the source of liquid to one or more of the aforemen tioned vessels. This method reduces the number of solenoid control valves to two but is likewise laborious when the number of vessels to be supplied is greater than two. Furthermore, the piston and slide-valve system in the distributor is incapable of 105 supplying some vessels separately.

The object of the invention is to obviate these disadvantages. The invention provides a cheap multiple-liquid dispenser which can supply liquid to each component receiver separately, irrespective of the number of receivers; the invention also provides a device such as a washing machine, comprising the multiple-liquid dispenser.

The invention relates to a multiple-liquid supply system comprising a means controlling the intake of a liquid at the inlet and a connecting:3ystem connecting the inlet to a number of outlets which, according to the invention, comprises at least one simple solenoid valve for controlling the intake of liquid and (n-1) liquid guide devices forming a connecting system between the sing,e inlet and the outlets, the guide devices being connected in cas cade, having three ways and a valve individually controlled by the incoming liquid in a specific sequence determined by a fixed number of openings 125 and closings of the solenoid valve for fixed periods, a hole of predetermined si ze for connecting to atmosphere being formed in the path of the incom ing liquid downstream of each of the guide devices.

The invention will be more clearly understood from the following description, by way of example, of a number of embodiments illustrated by the accompanying drawings in which:-

Figure 1 is a diagrammatic perspective view of a device constructed according to the invention, in the form of an underwear-washing maching; Figure 2 is a view in longitudinal section, on a different scale, of a multiple liquid dispenser according to a first embodiment of the invention; Figure 3 is a view in longitudinal section, on a different scale, of a multiple liquid dispenser according to a second embodiment of the invention; Figure 4 is a cross-section along IV-IV of the dispenser in Figure 3; Figure 5 is a view in cross-section of the dispenser in Figure 3, along V- V; Figure 6 is a diagrammatic view of a multiple liquid dispenser according to a third embodiment of the invention; Figure 7 is a diagram of a first and second variant of the dispenser in Figure 6; Figure 8 is a partial diagram of a third variant of the dispenser in Figure 6; Figure 9 shows a rose forming part of the variant illustrated in Figure 8; Figure 10 is a diagram of a fourth variant of the assembly in Figure 6; and Figure 11 is a diagram of a fifth variant of the assembly in Figure 6.

Figure 1 illustrates a device constructed according to the invention, i.e. an underwear-washing machine 1. Machine 1 has a number of receiving and distributing means which have to be supplied with liquid during operation. The means can e.g. be a vessel for wash i ng-powder 2, a bleach and disi nfectant vessel 3, and a softener vessel 4. In machine 1, the three vessels are connected via a multiple liquid dispenser 5 to a source of liquid, diagrammatically indicated by a water distribution pipe system 6.

According to the invention, the multiple liquid dispenser 5 illustrated in Figures 1 and 2 has a body comprising a single liquid inlet 7 and n liquid outlets e.g. three outlets 8, 9 and 10. The n liquid outlets are connected to the liquid inlet 7 by (n-1) liquid guide devices 11 connected in cascade. The guide devices 11 comprise three-way T devices comprising a valve 12 individually actuated by the incoming liquid in a specific sequence. The illustrated guide devices 11 each have a tubular cavity in the form of a sideways T having a central body 13 representing the arms of the T and prolonged by two end parts 14,15 having a smaller cross-section than the body and forming a first and second way; the guide devices also have a tubular central part 16 forming the body of the T and constituting a third way, The walls 17, 18 connecting the central body 13 to the tubular bottom parts 14 and 15 of the T cavity form the top and bottom seats of valve 12. Valve 12 moves freely in the central body 13. Valve 12 can move between seats 17 and 18 along the central body 13 in the T cavity in orderto open and close the ways constituted by the end of the T arms. The top tubular end part 14 of device 11 is connected to one outlet of dispenser 5. The bottom end part 15 of device 11 is connected to the central part 16 of the next guide device 11, or to the 2 GB 2 056 621 A 2 last outlet. The tubular central part 16 of the first device 11 is connected to the inlet 7 of the multiple liquid dispenser.

In the example illustrated in Figure 2, two devices 11 have been used to connect the three outlets 8, 9 and 10 to the inlet 11 of the multiple dispenser 5.

The tubular central part 16 of the first device is connected to the liquid inlet 7 by a connecting pipe system 19. The top tubular end part 14 is connected to the first liquid outlet 8 and the bottom tubular end part 15 is connected to the tubular central part 16 of the second device 11 via a liquid leak system 20 and a connecting pipe system 21. The top tubular end part 14 of the second device 11 is connected to the second liquid outlet 9 and its bottom tubular end part 15 is connected to the third liquid outlet 10 via a liquid leak system 20 and a connecting pipe system 22.

The illustrated liquid leak system 20 has a leak cavity 23 which connects the bottom tubular end part 15 of device 11 to a connecting pipe system at one end and to atmosphere at the other end via a hole 25 of predetermined size. The system 20 also has an injection nozzle 26 prolonging the bottom tubular end part 15 of device 11 via cavity 23 for a short distance and at the axial level of the pipesystem inlet, and forming a venturi device.

The holes 25 forconnecting to atmosphere can be formed in a collector 24which opens to atmosphere.

In the example illustrated in Figure 2, valve 12 comprises a ball made of material having a density less than that of the incoming liquid travelling through device 11. When the liquid is water, the ball has a density less than 1. The motion of valve 12 from one seatto another inside body 13 of the T cavity of a device 11 is brought about by the liquid which, according to a feature of the invention, is introduced therein through a solenoid valve 27 (Figure 1) in a specific sequence determined by a fixed number of openings and closing of solenoid valve 27 forfixed periods.

In the example illustrated in Figure 2, valves 12 are inoperative and press through gravity against their bottom seat 18, closing the bottom tubular end part 15 of the respective devices 11. When liquid is first introduced into dispenser 5 by opening the solenoid valve 27, the liquid travels through inlet 7, pipe system 19 and the tubular central part 16 and enters the central body 13 of the first device 11. As a result of the pressure of incoming liquid, valve 12 is held 115 pressed against its bottom seat 18 and closes the bottom tubular end part 15 of the first device 11. The incoming liquid has to follow the only free way, which consists of the top tubular end part 14 of the first device 11, and flows out through the first outlet 120 8. Liquid is being supplied through the first outlet 8. If solenoid valve 27 is now closed, the incoming liquid ceases to exert pressure on valve 12, which leaves its bottom seat 18 and rises through buoyan60 cyto its top seat 17. The remaining liquid in dispenser 5 flows down into the first leak cavity 23 and out through holes 25 into collector 24. The size of the hole 25 connecting to atmosphere is chosen so that the body 13 of device 11 is kept, during a 65 chosen -delay- time, sufficiently full of residual liquid to hold the valve near its top seat 17. If solenoid valve 27 is again opened within the delay time, the incoming liquid travels through the bottom tubular end part 15 of the first device 11, since the first outlet 8 is closed by the floating valve 12. The incoming liquid then flows through nozzle 26 and pipe system 21 and enters the second device 11. Valve 12 of the second device 11, which is on its bottom seat 18, is pressed against seat 18 by the incoming liquid and thus closes the bottom tubular end part 15. The incoming liquid 11 travels towards the top tubular end part 14 of the second device 11 and flows out through the second outlet 9 of assembly 5. The incoming liquid continues to travel through the second outlet 9 if solenoid valve 27 is kept open. Liquid is being supplied through the second outlet 9.

If solenoid valve 27 is again closed, the supply of liquid Into assembly 5 is stopped and the valve 12 of the second device 11 leaves its bottom seat 18 and rises through buoyancy to its top seat 17.

The liquid remaining in dispenser 5 flows down into the first and the second leak cavity 23 and out through the respective, holes 25 in to the leak co 11 ecto r 24.

If liquid is again introduced into dispenser 5 by opening the solenoid valve 27 within the delay time, the incoming liquid pushes the floating valves 12 against their top seat 17. The first outlet 8 and the second outlet 9 are thus closed. The incoming liquid thereupon travels through the two devices 11 to reach the pipe system 22 and the third outlet 10 of assembly 5. Liquid is being supplied through the third outlet 10.

If solenoid valve 27 is again cl osed, the flow of liquid into dispenser 5 is stopped. When solenoid valve 27 has been closed for longer than the delay time, the remaining liquid flows completely out of the two guide devices 11 through holes 25 and valves 12 return through gravity to their inoperative position and rest on their respective bottom seats 18. The multiple dispenser 5 returns to the inoperative state.

In short, when dispenser 5 is inoperative, liquid - can be supplied through the first outlet 8 simply by opening solenoid valve 27; the incoming liquid travels through the. pipe system 19, enters the first guide device 11 and flows out through outlet 8. In order to supply liquid through the second o utlet 9, valves 12 are actuated by the liquid, which is introduced in a specific sequence which will now be described. At the beginning, dispenser 5 is in its inopereative position a and solenoid valve 27 is opened a first time for a fixed duration just sufficient to fill the single first guide device 11 with liquid. Solenoid valve 27 is then closed for a fixed time, less than the delay time, so that valve 12 can leave its bottom seat 18 and travel to the top seat 17. Finally the solenoid valve is reopened a second time for the desired supply period, during which the incoming liquid travels through the pipe system 19, the bottom part of the central body 13 of the first device 11, the nozzle 26, the pipe system 21, and the top part of the central body 13 of the second device 11 and flows out through the second outlet 9. In the aforemen- 3 GB 2 056 621 A 3 tioned operation of supplying liquid through the second outlet 9, the times during which solenoid valve 27 are opened and closed in order to actuate valve 12 are both fixed, and no liquid escapes through the first outlet 8 of dispenser 5. If it does not matter if a certain quantity of liquid leaks through outlet 8 during the operation of supplying liquid through the second outlet 9, the solenoid valve 27 for actuating valve 12 can be opened for longer than the fixed time, i.e. lodger than the time needed for just filling the first device 11 with liquid.

In order to supply liquid through the third. outlet 10, valves 12 are actuated by the incoming liquid in a specific sequence, which will now be described.

When dispenser 5 is in the inoperative state, solenoid valve 27 is opened a first time for a fixed period less than the delay time, so that valve 12 of the first device 11 can leave its bottom seat 18 and travel to the top seat 17 so as to close the first outlet 8. Next, the solenoid valve is re-opened a second time for a fixed period just sufficient to fill the second device 11 with liquid, then closed a second time for a fixed period less than the delay time so that valve 12 of the second device 11 can leave its bottom seat 18 and travel to its top seat 17 so as to close the second outlet 9. Finally, the solenoid valve is re-opened a third time for the desired supply period, when the in incoming liquid travels through the two devices 11 and the connecting pipe system 22 flows out through the third outlet 10.

Since devices 11 have a similar structure, there is equality between the fixed periods during which the solenoid valve 27 is open to actuate the two valves 12, and also between the fixed periods during which solenoid valve 27 is closed toactuate valve 12.

In the multiple liquid dispenser, the guide device 11 can be at the same height (Figure 2) or at different heights, i.e. one device 11 being lower than the following device 11. The dispenser 5 can be in a number of parts, e.g. three (Figure 2), which are assembled by known securing means (not shown). Nozzles 26 are positioned e.g. when dispenser 5 is assembled. When the incoming liquid is flowing, nozzles 26 cooperate with leak cavities 23 and pipe systems 21, 22 to produce a venturi effect which greatly reduces leaks of liquid through holes 25.

According to a variant illustrated in Figures 3, 4 and 5, the multiple liquid dispenser 28 has a single inlet 29 for liquid and n outlets for liquid, e.g. three outlets 30, 31 and 32. The n outlets are connected to the single inlet 29 by (n-1) guide devices 33 mounted in cascade and constructed in similar manner to those in the first example, e.g. made up of three-way T-shaped devices and valves 34 actuated by the incoming liquid. Each guide device 33 has a bottom seat 35 and a top seat 36 for valve 34. In dispenser 28, the liquid inlet 29 is connected, as in the example in Figure 1, to a source of liquid 6 via a solenoid valve 27, and connected to the central tubular part 37 of the first guide device 33.

The first outlet 30 of dispenser 28, which is siphon-shaped (Figure 4), is connected to the top tubular end part 38 of the first device 33 and the bottom tubular end part 39 thereof is connected to the tubular central part 37 of the second device 33 via a connecting pipe system 40. The top tubular end part 38 of the second device 33 is connected to the second or siphon-shaped outlet 31 (Figure 5) of dispenser 28 and the bottom tubular end part 39 of the second device 33 is connected to the third outlet 32 by a connecting pipe system 41. Downstream of devices 33, the pipe systems 40 and 41 are connected to atmosphere respectively by holes 43 and 44 which open into a collector 42.

In an illustrated variant (Figures 3 - 5) valve 34 is a ball made of material having a density less than or near the density of the liquid introduced into dispenser 28.

When inoperative, valves 34 rest on the bottom seats 35. When solenoid valve 27 is open, the liquid flows into the first guide device 33 via inlet 29, holds valve 34 against its bottom seat 35, and flows out through the first outlet 30 and to the top tubular end part of the first device 33. Liquid is being supplied to the first outlet 30. If solenoid valve 27 is opened and closed for a fixed period, just sufficient to fill the first device 33 with liquid, valve 34 leaves its bottom seat 35. and rises through buoyancy to its top seat 36. If it does not matter if liquid leaks through the first outlet 30, the fixed first opening period can be exceeded. If the density of valve 34 is near that of the incoming liquids, the rise of valve 34 is assisted and accelerated through suction produced by siphoning resulting from the discharge of residual liquid from the first device 34 through the first or siphon-shaped outlet 30, owing to the presence of the hole 43 connecting to the exterior, i.e. to atmosphere.

If solenoid valve 27 is re-opened a second time after a fixed closing period, the incoming liquid travels through the bottom tubular end part 39 of the first device 33, enters the pipe system 40 and the second device 33, and flows out through the top tubular end part 38 of the second device 33 and the second or siphon-shaped outlet 31, the valve 34 of the second device 28 being pressed against its bottom seat 35. A small, tolerated amount of intake liquid also flows out through hole 43, which is given a predetermined size. Liquid is being supplied to the second outlet 31.

If the solenoid valve 27 is alternatively opened twice for a given time and closed twice for another given time, the incoming liquid allows the valves 34 of the two devices 33 to return to their respective top seats 36. Preferably the second device 33 in dispen- ser 28 is at a higher level than the first device 33, as shown in Figure 3. If the two devices 33 are at different levels, it is easy to move valve 34 off the second device 33 from-its bottom seat 35 to its top seat 36 without interfering with the valve 34 of the first device 33, which is already in its top position.

If the solenoid valve 27 is now re-opened a third time, the incoming liquid travels through the two devices 33, enters the pipe system 41 and flows out through the third outlet 32. Liquid is being supplied to the third outlet 32.

Thus, dispenser 28 operates in similar manner to dispenser 5. As before, valves 34 of devices 33 are actuated in a specific sequence by the liquid admitted into dispenser 28, the sequence being deter- mined by a fixed number of openings and closings 4 GB 2 056 621 A 4 of solenoid valve 27 for fixed periods.

Solenoid valve 27 can be actuated either manually or automatically by a programmer (not shown) of machine 1.

As Figures 3 - 5 show, dispenser 28 can be in two parts 45 and 46 in accordance with the prior art, the parts being assembled by securing means which are likewise known and are not shown.

In dispenser 28, the free ends of outputs 30, 31 and 32 are preferably cut slantwise. This structure can be used.to obviate dis-advantageous surface tension of the liquid, and facilitates the flow of remaining 1 liquid as soon as solenoid valve 27 is closed, thus improving the efficiency of the multiple liquid dis- penser.

According to a third embodiment, diagrammatically illustrated in Figure 6, a multiple liquid dispenser 47 has a single inlet 48 for liquid and n outlets for liquid, e.g. three outlets 49, 50 and 51. The n outlets are connected to the single inlet 48 by (n-1), e.g. two, guide devices 52 connected in cascade and operating in similar manner to those in the first two examples and comprising three-way T devices and valves 53 actuated by the incoming liquid in a specific sequence. In the present embodiment, the illustrated guide means 52 are each formed with a tubular cavity in the shape of a T on its side, having a vertical part 54 representing the arms of the T and a horizontal central part 55 representing the body of the T. Two horizontal tubular parts 56, 57 having a smaller cross-section than the vertical part 54 are formed in the wall of the end regions of the vertical part 54 representing the arms of the T, on the opposite side from the horizontal central part 55. The top tubular horizontal part 56 and the bottom part 57 of the T arms form a first way and a second way, whereas the horizontal central part 55, which repre sents the body of the T, forms a third way. The third way is connected via inlet 48 to solenoid valve 27 (Figurel). Atop vertical seat 58 of valve 53 is formed 105 on the wall of the vertical part 54 around the horizontal tubular part 56, and a bottom vertical seat 59 of valve 53 is formed on the wall of the vertical part 54 around the horizontal tubular part 57. The end parts of the vertical part 54 representing the arms of the T of the guide device 52 form abutments 60, 61 and also form surfaces abutting the valve 53, which can move along the vertical part 54 between its seats 58 and 59. When the solenoid valve 27 stops and the liquid in the guide device 52 is discharged through the bottom horizontal tubular part 57, valve 53 rests on abutment 61 and not on its botiom vertical seat 59. The resulting advantageous structure prevents valve 53 from sticking to its bottom seat 59, which may be caused interalia by deposits of dirt whicl-Y dry after the liquid has been discharged. This advantage can be further improved by forming ribs 52 on the surfaces of abutments 60 and 61 in orderto reduce the capillaryforces which, as a result of the film of liquid between valve 53 and the flat surfaces of the abutments, hold valve 53 back and interfere with its operation. The ribs also form a refuge or reservoir for impurities.

In dispenser47, the liquid inlet 48 is connected, as in the example in Figure 1,to a source of liquid 6 via 130 solenoid valve 27 (Figure 1) and connected to the horizontal tubular central parts 55 of a first guide device 52. The first outlet 49 of assembly 47 is connected to the top horizontal tubular part 56 of th first device 52. The bottom horizontal tubular part 57 of the first device 52 is connected to the horizontal tubular central part 55 of a second device 52 by a tube system 63. The top horizontal tubular part 56 of the second device 52 is connected to the second outlet 50 of dispenser 47 and the bottom horizontal tubular part 57 of the second device 33 is connected to the second outlet 51 by a tube system 64. The structure of the first tubular outlet 49 is particularly important in ensuring efficient operation of a liquid dispenser as shown in Figure 6. If the diameter of outlet tube 49 is too large, air may rapidly rise through outlet 49 when the liquid supply is cut off via solenoid valve 27 during the phase when valve 53 has to move from its low position (i.e. its bottom seat) to its top position (i.e. its top seat), so that air will fill the top part of device 52 and impede valve 53 and make it practically impossible for it to reach its top seat 58. If the diameter of the outlettube 49 is too small, valve 53 can easily occupy its top seat 58, but during the phase when valve 53 must leave its top seat and descend to the level of its bottom seat 59, the air cannot rise in outlet 49, i.e. the column of liquid is trapped in outlet 49 and valve 53 will thus be held against its top seat. In another case where the diameter of the outlet tube 49 is inadequate, plugs produced by fractionating liquid may form in outlet 49 and prevent air from rising. According to the invention, to ensure efficient operation of assembly 47, the outlet tube 49 must remain full of liquid during the entire rise of valve 53 to its top seat 58; after seat 58 has been occupied by valve 53, the outlet tube 49 enters and fills with air so that valve 53 can come away from its top seat 58 during the descending period.

To this end, in the illustrated example,.assembly 47 comprises a liquid reservoir 65 connected to atmosphere by an aperture 66 and connected to a top part of the outlet tube 49 by a pipe 67 of predetermined diameter and by an outlet tube 49 of, predetermined diameter ending in a nozzle 68 of predetermined diameter.

The diameter of the outlet tube 49 is preferably greater than or equal to 8 mm whereas the diameter of pipe 67 and nozzle 68 is of the order of 1.2 and 5 mm respectively.

During the phase when valve 53 returns upwards, the given-diameter nozzle 68 prevents airfrom rising in the outlet tube 49, which is also supplied with liquid via reservoir 65 through pipe 67. The guide device 52 and the outlet tube 49 thus remain full of liquid and valve 53 can rise and occupy its top seat 58 in normal manner. The liquid reservoir 65, which enters through pipe 67, fills the outlet tube 49 and nozzle 68 and prevents air from rising along tube 49.

However, the air required for releasing valve 53 from its top seat 58 during the descent phase thereof is supplied from reservoir 65 when the reservoir is empty.

The tube systems 63, 64 connected to the bottom horizontal tubular parts 57 of the first and second Z GB 2 056 621 A 5 suide devices 52 each have a liquid leak or emptying device 69 at their base. Device 69 is a tube or tubular cavity, the bottom of which has a leak orifice 70. The diameter of the leak orifice is chosen in dependence on the desired emptying time of guide devices 52, and more particularlythe time taken by vaiv,s 53 to 'descend from theirtop seat 58 until theyaare in line with the horizontal tubular central part 55 of devices 56. In the illustrated example, the diameter of the leak orifice 70 is of the order of 0.6 - 0.7 mm and the diameter of the tube or tubular cavity forming the liquid leak device 69 is at least 8 mm. The tube or tubular cavity constituting the liquid leak device 69 contains at least sufficient liquid 71 to overcome the capillary tension at the leak orifice 70.

In the illustrated example, the diameters chosen for the tube or tubular cavity and the leak orifice 70 are 8 and.6 mm respectively, and the height 72 of the liquid 71 is of the order of 48 mm.

According to the invention, the bottom horizontal 85 tubular part 57 of device 52 must be extended inside the liquid 71 filling the liquid leak device 69, in order to produce a negative pressure in the guide device 52 and thus force valve 53 to descend if it is held to its top seat by a negative pressure in the top horizontal tubular part 56 and the corresponding outlet of dispenser 47. In the illustrated example, the top part of the tube or tubular cavity 69 is divided in two by a sealing-tight diametric partition 73, the end of which is immersed in the liquid 71, so that the - liquid travelling in systems 63 and 64 must travel through liquid 71. The aforementioned structure can be used to accentuate the negative pressure in devices 52 during the emptying thereof through orifices 70, thus facilitating the descent of valve 53.

In order to prevent any air rising in the guide devices 52 during the motion of valves 53 from their bottom seat 59 to their top seat 58, the tube systems 63, 64 comprise a siphon 74 in the portion separating devices 52 from the liquid leak devices 69. The siphon 74 contains an amount of liquid at least equal to the volume of valve 53, i.e. to the volume of liquid displaced by valve 53.

As in the previous examples, valve 53 comprises a ball made of material having a density less than or near the density of the liquid introduced into dispense r 47.

When inoperative, valves 53 rest on ribs 62 of surfaces or abutments 61. When solenoid valve 27 is open, liquid flows into the first guide device 52 via inlet 48. Some of the liquid travels along the bottom seat 59 ofvalve 53, the bottom horizontal tubular part 57. the siphon 74 and the leak device 69. The flow of liquid to orifice 70 produces a negative pressure which attracts valve 53 to its bottom seat 59, so that liquid cannot flow out through the bottom seat 59 of valve 53. The pressure of liquid entering device 52 intensifies the pressure of valve 53 against the bottom seat 59. The other part of the incoming liquid.escapes through the first outlet 49 through the top horizontal tubular part 56 of device 52. Liquid is being supplied through the first outlet 49 through tite top horizontal tubular part 56 of device 52. Liquid is being supplied through the first outlet 49. If solenoid valve 27 is open fora fixed time sufficient to fill the first device 52 with liquid and is then closed, valve 53 leaves its bottom seat 59 and rises through buoyancy to its top seat 58. If the density of valve 53 is near that of the incoming liquid, the rise of valve 53 is assisted and accelerated by the suction produced by siphoning through the evacuation of liquid through the first outlet 49. Outlet 49 is likewise supplied by liquid reservoir 65 through orifice 67, so that air cannot enter through outlet 49 and occupy the top part of device 52 and thus tend to prevent valve 53 from occupying its top vertical seat 58.

If valve 27 is again re-opened after a fixed closure time, i.e. is opened a second time, the incoming liquid travels through the bottom part of device 52, enters the bottom tubular part 57 and the tubular system 63, i.e. the siphon 74, and the leak device 69 and enters the second guide device 52 and flows out th through the second outlet 50. Liquid is being supplied through the second outlet 50.

If solenoid valve 27 is alternatively opened twice for a predetermined time and then closed twice for another predetermined time, the incoming liquid enables the valves 53 of the two guide devices 52 to return to their respective top seats 58. The rise of valve 53 of the second device 52 is also easy an d accelerated by the suction effect of siphoning as a result of the discharge of liquid through the second outlet 50, which is likewise supplied by the second liquid reservoir 65 through orifice 67. thus prevent- ing air from entering through the second outlet and rising and occupying the top part of the second device 52, thus tending to prevent valve 53 of the second device from occupying its top seat 58.

If the solenoid valve is no re-opened a third time, the incoming liquid travels through the two devices 52, enters the tubular system 64, i.e. siphon 74 and the leak device 69, and flows out through the third outlet 51. Liquid is being supplied through third outlet 51.

Thus, dispenser 47 operates in similar manner to those in the previous examples. As before, valves 53 of devices 52 are actuated by the liquid introduced into dispenser 47, the process being in a specific sequence determined by a fixed number of openings and closings of solenoid valve 27 forfixed times.

In a first variant of the invention, diagrammatically illustrated in Figure 7, the liquid reservoir 65 is supplied by the liquid introduced into device 52 via a capillary tube 75 which connects the top region of reservoir 65 to the top region of the top part 54 of the cavity in device 52. The diameter of tube 75 is chosen so that only liquid can travel through it and the capillary forces of the liquid therein prevent any air from travelling from reservoir 65 into the guide device 52. In the illustrated example the diameter of the capillary tube 75 is from about 0.6 to 0.3 mm.

In a second embodiment diagrammatically illustrated in Figure 7, a third seat 76 of valve 53 is formed around the tubular central part 55 of the guide device 52. If a negative pressure occurs in the liquid-supplying source 6 and solenoid valve 27 is open, the two guide devices 52 will both be at negative pressure. Normally the negative pressure in device 52 is small if there is no stoppage of the outlet forming the first part, which is connected to 6 GB 2 056 621 A 6 atmosphere, If the aforementioned outlet is blocked, the negative pressure in device 52 causes the liquid to rise therein from siphon 74. The liquid raises valve 33, which is sucked and pressed against its third seat 76. When the valve closes the horizontal tubular central part 55, the negaiive pressure in device 52 ceases and stops any liquid or products being sucked through the other outlets of dispenser 57.

This avoids any riskthat the source 6 will be polluted by the aforementioned products or liquid sucked into source 6 when at negative pressure.

In a third embodiment, illustrated in Figure 8, the first outlet 49 of the multiple liquid dispenser ends in a rose 77 which replaces nozzle 68 in Figures 6 and 7.

Rose 77 has a number of holes 78 which are smaller in diameterthan nozzle 68. In the example illustrated in Figures 8 and 9, the diameter of holes 78 in rose 77 is of the orderto 2 to 4 mm. This structure has the advantage of increasing the reliability since, if the diameter of hole 78 is small, there is a corresponding reduction in the risk of air rising in the first outlet of the multiple liquid dispenser. It also reduces the pressure drop at the liquid outlet, since it increases the total flow cross-section as a result of the replacement of nozzle 68 by a number of holes 78 in rose 77.

In a fourth variant, illustrated in Figure 10, the first outlet49 of the multiple liquid supply device ends in a siphon 79 filled with liquid. Siphon 79 replaces nozzle 68 (Figures 6 and 7). This structure has the advantage of preventing air from rising in the first outlet 49 without thereby increasing the pressure drops at the liquid outlet.

In a fifth embodiment, illustrated in Figure 11, dispenser 47 comprises a tank 80 for liquid, emptied by a nozzle 81. The tank 80, which replaces the liquid reservoir 55, is disposed at the end of the first outlet 49 of dispenser 47. When the liquid is being supplied from the first outlet 49 of dispenser 47. When the liquid is being supplied from the first outlet 49, tank 80 fills. Consequently the first outlet 49 does not extend directly into atmosphere. No air can rise in outlet 49 during the time when the end of outlet 49 is immersed in the liquid in tank 80. When the liquid has been emptied from the tank, air can again flow freely into outlet 49. Consequently the time available for valve 53 to rise from its bottom seat to its top seat can be adjusted by adjusting the volume of tank 80 and/or the diameter of nozzle 81.

Claims

1. A multiple liquid supply assembly comprising a means controlling the intake of a liquid at the inlet and a connecting system connecting the inlet to a number of outlets, characterised in that it comprises at least one simple electrically operated valve for controlling the intake of liquid, and (n-1) liquid guide devices forming a connecting system between the single inlet and the outlets, the guide devices being connected in cascade, having three ways and a valve individually controlled by the incoming liquid in a specific sequence determined by a fixed number of openings and closing of the el ectrica 1 ly-o pe rated valve for fixed periods, a hole of predetermined size for connecting to atmosphere being formed irt the path of the incoming liquid downstream of each of the guide devices.

2. An assembly according to claim 1, characte- rised in that it comprises three-way liquid guide devices each comprising a cavity in the shape of a T on its side, the top tubular end part of the arm of the^ T forming a first way and being connected to one of the corresponding outlets of the dispenser, the bottom tubular end part forming a second way and being connected either to the tubular central part representing the body of the T of the next device or, in the case of the last guide device in cascade, being connected to the last of the dispenser outlets, whereas the central tubular part representing the body of the Tforms a third way and is connected either to the bottom tubular end part of the preceding device or, in the case of the first of the guide devices in cascade, is connected to the dispenser inlet.

3. An assembly according to claim 1 or2, characterised in that the threeway T-shaped liquid guide devices each have a free valve in the central body representing the arms of the T, the valve being used to open and close the way represented by the end parts of the arms of the T, the valve comprising a ball made of material having a density less than that of the liquid entering the devices, the valve having top and bottom seats at the level of the tubular end parts of the Tarms.

4. An assembly according to any of claims 1 to 3, characterised in that it comprises liquid guide devices at the same height as one another.

5. An assembly according to claim 1 or2, characterised in that it comprises liquid guide devices disposed so that each is lower than the next device and higher than the preceding device.

6. An assembly according to any of claims 1 to 5,. characterised in that it comprises a nozzle sur- rounded by a leak cavity and forming a venturi device downstream of the liquid guide devices between the bottom tubular end part of the T arms of a guide device and a connecting pipe system.

7. An assembly according to any of claims 1,2 and 5, characterised in that it comprises outlets eacli constructed as a siphon.

8. An assembly according to claim 7, characterised fri that the three-way T-shaped liquid guide devices each have a free valve in their central body, representing the arms of the T, the valve comprising a ball made of a material having a density nearthat of the liquid admitted into these devices.

9. An assembly according to claim 7, characterised in that it comprises outlets in the form of siphons having free ends cut slantwise.

10. An assembly according to claim 1, characterised in that it comprises three-way liquid guide devices each comprising a cavity in the shape of a sideways T having a vertical part representing the arms of the T and two horizontal tubular parts at the two ends, one part forming the first way connected to a first outlet of the dispenser and the other part forming the second way connected either by a tube system to the horizontal tubular central part repre- senting the body of theTof the nextdevice or, inthe 1 7 GB 2 056 621 A 7 case of the last guide device in cascade, connected by a tube system to the last output of the dispenser, - the horizontal tubular central part representing the body of the T forming the third way and connected either to the second way of the preceding device or, in the case of the first guide device in cascade, connected to the dispenser inlet.

11. An assembly according to claim 10, characterised in that the tube system connected to the second way of the guide device comprises a liquid leak device comprising a tube ortubular cavity formed with a leak orifice having a diameter chosen in dependence on the time to empty the guide device, the tube system also comprising at least one load of liquid which can overcome the capillary tension at the leak orifice.

12. An assembly according to claim 11, characterised in that the tube system comprises a liquid leak device comprising a tube having a diameter greater than or equal to 8 mm and having a leak orifice of a diameter of approximately 0.6 mm and adapted to hold at least one filling of liquid approximately 48 mm high.

13. An assembly according to claim 11, characte- rised in that the tube system in the tube comprising the liquid leak device has a sealing-tight central partition the end of which is immersed in the liquid filling and divides the top part of the tube into two.

14. An assembly according to any of claims 10to 13, characterised in that the tube system upstream of the liquid leak device comprises a siphon which can contain an amount of liquid at least equal to the volume displaced by the valve.

15. An assembly according to anyone of claims 1, 2 and 10, characterised in that, at the end of its first outlet, it has a nozzle having a diameter less than the diameter of the first outlet.

16. An assembly according to claim 15,characterised in that it has a first outlet having a diameter of at least 8 mm and a nozzle having a diameter of approx. 5 mm.

17. An assembly according to any of claims 1, 2, 10 and 15, characterised in that it comprises a liquid reservoir connected to a place upstream of the outlet, which is connected by a pipe to the first way of the three-way guide devices.

18. An assembly according to claim 17, characterised in that it comprises a capillary tube connecting the top region of the guide device to the top region of the liquid reservoir.

19. An assembly according to claim 18, characterised in that it comprises a capillary tube having a diameter between 0.6 and 0.3 mm and connecting the liquid reservoir to the guide device.

20. An assembly according to anyone of claims 1, 2 and 10, characterised in that, atthe end of its first outlet, it has a rose having a number of holes smaller in diameter than the first outlet.

21. An assembly according to claim 20, characte- rised in that, at the end of its outlet it has a rose having holes between 2 mm and 4 mm in diameter.

22. An assembly according to anyone of claims 1, 2 and 10, characterised in that it has a liquid-filled siphon at the end of its first outlet.

23. An assembly according to anyone of claims 1, 2 and 10, characterised in that, atthe end of its first outlet, it has a liquid tank comprising an emptying orifice.

24. Apparatus characterised in that it comprises a multiple liquid supply assembly constructed according to any of claims 1 to 23.

25. A multiple liquid supply assembly substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

Printed for Her Majesty's Stationery Office by Croydon Printing Company Limited, Croydon, Surrey, 1981. Published by The Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies may be obtained.