GB1600766A - Metering device for dispensing liquid media - Google Patents

Description

(54) METERING DEVICE FOR DISPENSING LIQUID MEDIA (71) We. EATON S.A.M., a Company organised and existing under the laws of Monaco of Boulevard du Bord de Mer, Monaco (pte) BP-84, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention concerns metering devices for use, for example, in dishwashers for metering the supply of detergent during a washing operation.

The present application is one for a patent of addition to patent number 1,562,169.

The parent patent number 1,562,169 relates to a metering device for dispensing liquid media, for incorporating into a door which is pivotable about a horizontal axis between an open horizontal position and a closed vertical position, comprising a reservoir and a metering chamber for preparing a metered quantity of the medium which is to be dispensed by the metering device, a scoop chamber the bottom of which is situated higher than the bottom of the reservoir and the bottom of the metering chamber when the door is open, and a slope leading from the scoop chamber to the metering chamber, whereby when the door is upwardly pivoted to its closed position medium stored in the reservoir is transferred into the scoop chamber and when the door is downwardly pivoted to its open position medium passes from the scoop chamber via the slope into the metering chamber to form therein a metered quantity of medium for dispensing while the door is next in its closed position.

This metering device is characterised by a simple construction and reliable operation and furthermore by being able to store a large volume of liquid medium.

The object of the present invention is to further develop the metering device in the sense that while retaining the above-mentioned advantages the operational reliability is improved and where appropriate operation is facilitated.

According to the invention, there is provided a metering device for dispensing liquid media, for incorporating into a door which is pivotable about a horizontal axis between an open horizontal position and a closed vertical position, comprising a reservoir and a metering chamber for preparing a metered quantity of the medium which is to be dispensed by the metering device, a scoop chamber the bottom of which is arranged to be situated higher than the bottom of the reservoir and the bottom of the metering chamber when the door is open, and slope leading from the scoop chamber to the metering chamber, whereby when the door is upwardly pivoted to its closed position medium stored in the reservoir is transferred into the scoop chamber and when the door is downwardly pivoted to its open position medium passes from the scoop chamber via the slope into the metering chamber to form therein a metered quantity of medium for dispensing while the door is next in its closed position, the metering chamber being connected via a discharge valve to a discharge orifice for the medium, which orifice is arranged to be situated, at least partly, lower than the metering chamber when the door is upwardly pivoted.

In one preferred embodiment a duct situated in the casing of the device leads to the discharge orifice and is defined by walls which are integrally formed on at least one casing part. The duct may extend through the reservoir. The discharge orifice can also be disposed in a projecting screw-threaded socket which is adapted for mounting the casing on the door, thus producing particularly simple design conditions, and can be separated from the inlet orifice. It is possible in this embodiment to arrange that during the washing operation the duct is flushed through with water from the discharge orifice so that it always forms a reliable opening for the liquid medium.

If thermoplastic material is used, the device can have a double-skinned casing in which the duct is defined by two strip-like and substantially parallel walls situated at a distance from each other on one casing skin and by associated similar strip-like projecting walls which are integrally formed on the other casing skin, the walls of one casing skin being welded in liquid tight manner to the walls of the other casing skin. Accordingly, the duct which is integrally formed on both casing skins also contributes to the stiffening of the entire casing.

It is also advantageous to provide the metering device with an inlet orifice which is disposed in a screw-threaded socket adapted for mounting the casing on the door and is arranged to be situated at a level higher than the discharge orifice when the door is in its closed position. To this end, the duct in the casing can be arranged to extend at a downward angle.

Optical indicating means may also be provided. However, if an optical indicating device, normally constructed as an elongated plug of transparent material, is inserted into the inlet orifice, it must be removed when the liquid medium is poured in which means that during the filling operation itself it is not possible for the liquid level to be checked.

Some care is therefore required on the part of the operating person to ensure correct filling of the metering device. To simplify operation the casing can have a casing aperture which is separate from the filler orifice and into which an optical indicating device for the liquid level is inserted in liquid tight manner.

In this way the liquid level can be inspected in a simple manner during the filling operation and as a further simplification the system can be constructed so that the optical indicating device is disposed in a screwthreaded socket which is adapted for mounting the casing on the door.

This arrangement of the optical indicating device, separate from the filler orifice, is not confined to metering devices which are provided in the above-mentioned manner with an internally disposed duct leading to the discharge orifice; independently thereof it can also be used for metering devices which have a reservoir and a metering chamber.

In the manufacture of metering devices whose casing, consisting of thermoplastic material, is normally constructed in doubleskinned form, the two casing skins are welded to each other along a dividing plane.

To check whether the welded seams in the walls are liquid tight it is a common practice to subject the entire casing, for example via the filler orifice, to air pressure and to note any pressure drop which may occur. Such a pressure drop indicates that there must be a leakage at some place in the casing and accordingly a weld which is not perfect.

It is possible in this way to detect reliable welding in the region of the external walls of the casing but it is not possible to determine whether bulkheads in the interior of the casing are also welded in liquid tight manner.

Such internally disposed bulkheads may define, for example a metering chamber against the reservoir or they may define the above-mentioned duct that extends to the discharge orifice or, depending on the construction of the metering device, they may form venting ducts to mention only a few examples. Since the chambers or ducts defined by these bulkheads communicate via apertures in the interior of the casing with the space which forms the reservoir or with other spaces they are subjected on both sides to compressed air in the course of a compressed air test so that it is not possible to detect any leakage which occurs in the region of the bulkheads and permits liquid to pass through the bulkheads. On the other hand, leakages in the bulkheads may cause the metering chamber to discharge or to fill in an uncontrollable manner or cause the liquid in the reservoir to be uncontrollably discharged via the discharge orifice.

To provide a remedy and to enable the welded walls to be reliably tested for sealing tightness it is possible to arrange in accordance with the invention that at least one double bulkhead, comprising walls which extend substantially parallel with each other and are situated at a distance from each other, is disposed in the double-skinned casing, each of the two walls consisting of strip like wall portions which are integrally formed on the casing skins and are welded to each other in liquid tight manner and that the space between the two walls is vented towards the exterior of the casing.

When testing a metering device provided with such a bulkhead by means of compressed air it is possible, in the event of a faulty weld in the region of one of the two walls of the double-skinned wall, for air to be discharged to the exterior so that air pressure in the casing drops and thus indicates the presence of a leakage. In this case it is advantageous that at least the metering chamber is separated by a double bulkhead from the reservoir.

The arrangement of such double bulkheads in the casing of the metering device is not confined to those provided with the initially explained internally disposed duct which leads to the discharge orifice. Instead, it can be employed for all metering devices in which it is important to ensure that bulkheads are reliably welded in liquid-tight manner when the two casing skins are welded.

One embodiment of the invention is illustrated in the accompanying drawings in which: Fig. 1 is a side view of a dishwasher, with a metering device according to the invention with its door partially sectioned; Fig. 2 shows the metering device according to Fig. 1 in rear plan view, considered in relation to the dishwasher; Fig. 3 shows the metering device according to Fig. 2 in corresponding front plan view; Fig. 4 shows the metering device according toping. 2 in the open state, illustrating the two casing skins in perspective view; Fig. 5 shows the front or bottom casing skin of the metering device according to Fig.

4 in plan view; Figs. 6 and 7 show the metering device according to Fig. 2, sectioned along the line VI-VI and line VIl-VIl of Fig. 2 respectively; and Fig. 8 shows the metering device according to Fig. 2 in side view.

The dishwasher shown at 1 in Fig. 1 has associated with it a metering device 2 which is incorporated into the door 3 of the dishwasher 1 and is screwmounted on the rear or internal wall by means of the two screw-threaded sockets 4, 5. The door 3 can be vertically pivoted in a conventional manner about an axis 6 between an open horizontal, and a closed, vertical, position.

The metering device 2 comprises a doubleskinned casing 7 having rear and front casing skins 8,9, when considered in relation to the dishwasher with its door 3 closed. When the door is open, the skin 8 is arranged above the skin 9 and, in order to simplify the following description, the skin 8 is therefore considered to be the top skin and the skin 9 is considered to be the bottom skin. The two skins consist of thermoplastic material and are welded to each other in a dividing plane 10 so that corresponding wall portions of the two casing skins 8, 9 are joined to each other in liquid tight manner.

The device includes a reservoir 19, which may initially be filled by way of an inlet orifice 18 in the socket 4, a scoop chamber 22, and a metering chamber 20 arranged to discharge a metered quantity of a liquid medium to the interior of the dishwasher, in use, by way of a discharge orifice 45, as described in greater detail below.

As shown in Fig. 4, a slope 15, separated on one side by a low wall 14 from a supplementary reservoir 13 and separated on the other side by a low sloping wall 16 from the reservoir 19 is formed on the bottom of the casing skin 9 of the casing 7. The metering chamber 20 which, in use, is filled with liquid via an inlet 21 is located on one side of the slope 15. and on the other side of the slope 15 is the scoop chamber 22 the bottom 23 of which is inclined with respect to the horizontal and is situated at a level higher than that of the reservoir 19. The scoop chamber 22 is also separated from the reservoir 19 by the wall 16 and by a low wall 27 which, like the wall 16, is integrally formed on the casing skin 9 (Fig. 5) in the manner of a projecting strip. In the scoop chamber 22 there are provided on the bottom thereof three strip-like webs 24 25, 26 which are aligned approximately in the flow direction of the liquid medium to the metering chamber and are distributed in the manner illustrated in Fig. 5 to direct the flow of liquid medium from the scoop chamber 22 via the slope 15 into the metering chamber 20 and also stiffen the bottom 23 of the scoop chamber 22.

Adjoining the slope 15 and parallel to the bottom of the reservoir 19, a bottom portion 28 of the casing skin 9 extends towards the inlet 21 of the metering chamber 20.

In the metering chamber 20 there is disposed a displacement member 20, one side of which supports a projecting arm 31 which is slidably guided, by means of two integrally formed wings and a web 33, between two upright guide members 34 which are integrally moulded on the casing skin 9. The arm 31 is provided with a stud 35 which engages with the flights of a worm 36 that is rotatably supported on a bearing projection 37 associated with the bottom portion 28 of the casing skin 9. When the casing is assembled the worm 36 is accessible through the inlet orifice 18 in the screwthreaded socket 4 as may be seen by reference to Fig. 6. Rotation of the worm 36 enables the displacement member 30 to be moved up and down-by reference to Fig. 6--so.that the metered quantity of liquid medium which is to be dispensed by the metering chamber can be adjusted.

The metering chamber 20 is separated from the reservoir 19 by a double bulkhead 38 comprising two walls 39, 40 extending substantially parallel and at a distance from each other, each being integrally formed on the casing skin 8, and on the casing skin 9 in the manner illustrated in Fig. 6 and being welded to each other in liquid tight manner in the dividing plane 10. The space 41 between the two walls 39, 40 is open to the bottom of the casing 7, as disclosed, for example in Fig. 3.

A bore 43 (Fig. 6) leads from the metering chamber 20 into a duct 44 which extends at a downwardly inclined angle in the reservoir 19 when the door 3 is upright and leads to the discharge orifice 45 in the casing skin 8. The discharge orifice 45 is formed in the screwthreaded socket 5 on which a liquid-permeable discharge cap 46 is screwmounted. The duct 44 is defined on both sides by two walls 47, 48 which project in the manner of strips and are integrally formed on the two casing skins 8, 9 and are welded to each other in liquid tight manner in the dividing plane 10. The defining walls 47, 48 of the duct 44 can also be constructed in a manner similar to that of the double bulkhead 38 in which case a portion of the space between the walls which extend parallel with each other may then be vented towards the exterior of the casing as in the case of the double bulkhead 38 with the space 41 (Fig. 7).

A low wall 50, which extends parallel with the duct 44 at a distance therefrom and surrounds the end of the duct 45 in the manner shown in Figure 5 and advantageously influences the distribution of liquid, is also disposed in the reservoir 19 on the bottom of the casing skin 9.

A needle valve 52 (see Figures 3 and 6) which can be optionally opened by a traction magnet 54 via a lever 53 which is pivotably supported on the casing 7, is inserted in the bore 43 and in the opened state it establishes communication between the metering chamber 20 and the duct 44 by a route which can be seen from Figure 3. The metering device so far described is filled through the filler orifice 18 when the door 3 is downwardly pivoted. To monitor the state of liquid in the apparatus during operation an optical indicating device in the form of a so-called "optical eye" 55 (Figure 2) is inserted into the inlet orifice 18 and is screwmounted to the screw-threaded socket 4 in liquid tight manner by means of a screw cap 56. The optical eye 55 substantially comprises a cylindrical member which is conically pointed at one end and consists of transparent material. When inserted with its conical end in the device, the other end face indicates whether the liquid level is above, below or in the region of the conical end member, In an alternative embodiment it is also possible to arrange for the optical eye 55 to be inserted into a corresponding opening of the other screwthreaded socket 5 in which case the duct 44 is omitted and, to enable the metered liquid to be delivered from the device when needle valve 52 is opened, the opening 43 is rearranged to lead directly into the filler orifice 18 so that liquid can flow from chamber 20 through valve 52 and opening 43 and out via orifice 18 into the washing machine. This arrangement would have the advantage that the liquid level in the reservoir can be inspected during the filling operation.

In the filled reservoir 19, the liquid flows over the lowest place 60 of the wall 16 of the casing 7, when this is held horizontally, so that the metering chamber 20 is filled via the inlet 21 and via a low wall 57 (Fig. 6) which is situated in the region of the bottom portion 28. The metered amount of liquid, defined by the displacement member 30 remains in the metering chamber 20 after the door 3 is upwardly pivoted and on operation of the needle valve 52 flows through the bore 43 into the duct 44 and from there through the discharge orifice 45 into the interior of the dishwasher. During the washing operation water is able to enter the duct 44 through the discharge orifice 45 and flush through the said duct so that no residue of liquid medium can remain therein.

The scoop chamber comes into action as soon as the amount of liquid contained in the reservoir 19 is spent to the extent that it no longer comes over the low wall portion 60 when the metering device is in the horizontal position. With the metering device in the vertical position the scoop chamber 22 is filled over the low wall 27 from the reservoir 19 so that when the door is downwardly pivoted liquid disposed in the scoop chamber is able to flow over the slope 15 and the bottom portion 28 and through the inlet orifice 21 into the metering chamber 20 to fill the latter. In this way, irrespective of the state of charge of the reservoir 19, the metering chamber is always correctly filled and correct metering is thus ensured.

During the manufacturing procedure, the casing 7 is subjected to compressed air via the inlet orifice 18 while the discharge orifice 45 is kept closed so as to ensure that there is no leakage through the welding seam in the dividing plane 10 when the two casing skins 8, 9 are welded together. Any pressure drop that occurs is measured and indicates that welding of the external walls of the casing 7 is leaky at some place.

The sealing-tightness of the welds on the double bulkhead 38 is simultaneously tested in the course of this leakage test. Since the walls 39, 40 of the double bulkhead 38 are separated from each other by the externally vented space 41 it is possible, in the event of leakage at the weld of one of the two walls 39, 40 for air to escape into the space 41 and -therefore to the exterior. In this way it is possible to ensure that the metering chamber 20 is perfectly sealed against the reservoir 19 by the double bulkhead 38.

The construction of such a liquid tight bulkhead in the form of a double bulkhead 38 can also be provided for other walls in the interior or the casing 7 in which it is important to ensure liquid-tight closure.

Such a construction as a double bulkhead could be employed for the walls 47, 48 of the duct 44. It can however be also used for other metering devices for venting ducts and the like where such ducts are provided.

WHAT WE CLAIM IS: 1. A metering device for dispensing liquid media, for incorporating into a door which is pivotable about a horizontal axis between an open horizontal position and a closed vertical position, comprising a reservoir and a metering chamber for preparing a

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (14)

**WARNING** start of CLMS field may overlap end of DESC **. tight manner in the dividing plane 10. The defining walls 47, 48 of the duct 44 can also be constructed in a manner similar to that of the double bulkhead 38 in which case a portion of the space between the walls which extend parallel with each other may then be vented towards the exterior of the casing as in the case of the double bulkhead 38 with the space 41 (Fig. 7). A low wall 50, which extends parallel with the duct 44 at a distance therefrom and surrounds the end of the duct 45 in the manner shown in Figure 5 and advantageously influences the distribution of liquid, is also disposed in the reservoir 19 on the bottom of the casing skin 9. A needle valve 52 (see Figures 3 and 6) which can be optionally opened by a traction magnet 54 via a lever 53 which is pivotably supported on the casing 7, is inserted in the bore 43 and in the opened state it establishes communication between the metering chamber 20 and the duct 44 by a route which can be seen from Figure 3. The metering device so far described is filled through the filler orifice 18 when the door 3 is downwardly pivoted. To monitor the state of liquid in the apparatus during operation an optical indicating device in the form of a so-called "optical eye" 55 (Figure 2) is inserted into the inlet orifice 18 and is screwmounted to the screw-threaded socket 4 in liquid tight manner by means of a screw cap 56. The optical eye 55 substantially comprises a cylindrical member which is conically pointed at one end and consists of transparent material. When inserted with its conical end in the device, the other end face indicates whether the liquid level is above, below or in the region of the conical end member, In an alternative embodiment it is also possible to arrange for the optical eye 55 to be inserted into a corresponding opening of the other screwthreaded socket 5 in which case the duct 44 is omitted and, to enable the metered liquid to be delivered from the device when needle valve 52 is opened, the opening 43 is rearranged to lead directly into the filler orifice 18 so that liquid can flow from chamber 20 through valve 52 and opening 43 and out via orifice 18 into the washing machine. This arrangement would have the advantage that the liquid level in the reservoir can be inspected during the filling operation. In the filled reservoir 19, the liquid flows over the lowest place 60 of the wall 16 of the casing 7, when this is held horizontally, so that the metering chamber 20 is filled via the inlet 21 and via a low wall 57 (Fig. 6) which is situated in the region of the bottom portion 28. The metered amount of liquid, defined by the displacement member 30 remains in the metering chamber 20 after the door 3 is upwardly pivoted and on operation of the needle valve 52 flows through the bore 43 into the duct 44 and from there through the discharge orifice 45 into the interior of the dishwasher. During the washing operation water is able to enter the duct 44 through the discharge orifice 45 and flush through the said duct so that no residue of liquid medium can remain therein. The scoop chamber comes into action as soon as the amount of liquid contained in the reservoir 19 is spent to the extent that it no longer comes over the low wall portion 60 when the metering device is in the horizontal position. With the metering device in the vertical position the scoop chamber 22 is filled over the low wall 27 from the reservoir 19 so that when the door is downwardly pivoted liquid disposed in the scoop chamber is able to flow over the slope 15 and the bottom portion 28 and through the inlet orifice 21 into the metering chamber 20 to fill the latter. In this way, irrespective of the state of charge of the reservoir 19, the metering chamber is always correctly filled and correct metering is thus ensured. During the manufacturing procedure, the casing 7 is subjected to compressed air via the inlet orifice 18 while the discharge orifice 45 is kept closed so as to ensure that there is no leakage through the welding seam in the dividing plane 10 when the two casing skins 8, 9 are welded together. Any pressure drop that occurs is measured and indicates that welding of the external walls of the casing 7 is leaky at some place. The sealing-tightness of the welds on the double bulkhead 38 is simultaneously tested in the course of this leakage test. Since the walls 39, 40 of the double bulkhead 38 are separated from each other by the externally vented space 41 it is possible, in the event of leakage at the weld of one of the two walls 39, 40 for air to escape into the space 41 and -therefore to the exterior. In this way it is possible to ensure that the metering chamber 20 is perfectly sealed against the reservoir 19 by the double bulkhead 38. The construction of such a liquid tight bulkhead in the form of a double bulkhead 38 can also be provided for other walls in the interior or the casing 7 in which it is important to ensure liquid-tight closure. Such a construction as a double bulkhead could be employed for the walls 47, 48 of the duct 44. It can however be also used for other metering devices for venting ducts and the like where such ducts are provided. WHAT WE CLAIM IS:

1. A metering device for dispensing liquid media, for incorporating into a door which is pivotable about a horizontal axis between an open horizontal position and a closed vertical position, comprising a reservoir and a metering chamber for preparing a

metered quantity of the medium which is to be dispensed by the metering device, a scoop chamber the bottom of which is arranged to be situated higher than the bottom of the reservoir and the bottom of the metering chamber when the door is open. and a slope leading from the scoop chamber to the metering chamber, whereby when the door is upwardly pivoted to its closed position medium stored in the reservoir is transferred into the scoop chamber and when the door is downwardly pivoted to its open position medium passes from the scoop chamber via the slope into the metering chamber to form therein a metered quantity of medium for dispensing while the door is next in its closed position the metering chamber being connected via discharge valve to a discharge orifice for the medium, which orifice is arranged to be situated, at least partly, lower than the metering chamber when the door is upwardly pivoted.

2. A metering device as claimed in claim 1, in which a duct situated in the casing of the device leads to said discharge orifice.

3. A metering device according to claim 2, characterised in that the duct is defined by walls which are integrally formed 6n at least one casing part.

4. A metering device according to claims 2 or 3, characterised in that the duct extends through the reservoir.

5. A metering device according to any of the preceding claims. characterised in that the discharge orifice is disposed in a projecting screwthreaded socket adapted for mounting the casing of the device on the door.

6. A metering device according to claim 3, whose casing is double-skinned, the duct being defined by two strip-like and substantially parallel walls situated at a distance from each other on one casing skin and by associated similar strip-like projecting wall parts which are integrally formed on the other casing skin, the walls of one casing skin being welded in liquid tight manner to the walls of the other casing skin.

7. A metering device according to claim characterised by an inlet orifice which is disposed in a screwthreaded socket adapted for mounting the casing of the device on the door and is arranged to be situated at a level higher than the discharge orifice when the door is in its closed position.

8. A metering device according to claim 7, wherein the inlet orifice is provided with optical indicating means for the liquid level.

9. A metering device according to claim 2, characterised in that the duct is arranged to extend at a downwardly inclined angle in the casing of the device when the door is in its closed position.

10. A metering device according to claim 7, characterised in that it is provided with a casing aperture which is separate from the inlet orifice and has inserted therein in liquid tight manner optical indicating means for the liquid level.

11. A metering device according to claim 9, characterised in that the optical indicating means are disposed in a screwthreaded socket which is adapted for mounting the casing of the device on the door.

12. A metering device according to claim 1, whose casing is double-skinned, at least one double bulkhead, comprising walls which extend substantially parallel with each other and are situated at a distance from each other, being disposed in the double-skinned casing, each of the two walls consisting of strip-like wall portions which are integrally formed on the casing skins and are welded to each other in a liquid tight manner, the space between the two walls being vented towards the exterior of the casing.

13. A metering device according to claim 1, characterised in that at least the metering chamber is divided by means of a double bulkhead from the reservoir.

14. A metering device substantially as hereinbefore described with reference to the accompanying drawings.