The present invention relates to a valve device at dispensers which are adapted for dispensing portions of liquid or semi-liquid products, preferably foodstuff, from containers, and which dispensers have vacuum pumps for generating a negative pressure in passage systems through which the products are dispensed from the con- tainers.

Dispensers for dispensing portions of foodstuff, e. g. ketchup, mustard or dressing, are used most inten- sively a few hours during the day, e. g. at lunch time.

This means that the content in the containers from which the foodstuff is dispensed, is normally used up during said hours. The empty containers must then be replaced by full containers, which means that the dis- pensing must be interrupted for a while, prolonging the time of waiting for the customers. In the above case, you notice when the product in the container is used up, but in other cases you do not notice this and the dis- pensing goes wrong. Said latter case might occur when dispensing is to be carried through in milkshake machi- nes, dishwashing machines or washing machines.

In US 4 275 823 there is described a valve device which, when dispensing portions of liquid foodstuff, automatically closes a discharge passage when a contai- ner connected thereto is empty and opens another dis- charge passage for a full container connected thereto.

At this valve device, the valve body is controlled by a spring, which is disadvantageous inter alia because the spring is difficult to clean.

In US 4 819 693 there is described a valve device for controlling a gas flow. The valve body at this valve device is held in its two different positions by means of an electromagnet. For operating an electromagnet, connection to the electricity supply system is required, which, inter alia, for security reasons is not advisable

at dispensing devices for liquid or semi-liquid products such as foodstuff.

The object of the present invention has been to eliminate said problems and this is arrived at by means of a valve device having the characterizing features of subsequent claim 1.

Since the valve device is a permanent magnet device, an appropriate construction from an economic and security point of view is obtained, which is particularly suitable for use in connection with dispensers for liquid or semi- -liquid foodstuff.

The invention will be further described below with reference to the accompanying drawings, in which fig. 1 is an exploded view of the valve device accor- ding to the invention for a dispenser, whereby members forming part thereof are shown in section; fig. 2 schematically illustrates the valve device of fig. 1 with the members thereof in different positions; fig. 3 schematically illustrates portions of a con- tainer which is adapted for emptying by means of the dis- penser, and a coupling, connectable to the container, for a hose; and fig. 4 schematically illustrates portions of the container of fig. 3 with the coupling connected thereto.

The drawings illustrate a dispenser or dispensing device 1 for dispensing portions of liquid or semi-liquid products 2, preferably foodstuff, from two containers 3,4. The foodstuff may e. g. be ketchup, mustard, dres- sing or similar. In order to perform said dispensing, the dispenser 1 includes at least one vacuum pump 5 which is manually operated or operated in another way, e. g. by electricity or pneumatically.

The vacuum pump 5 communicates with one container 3 and 4 respectively, at a time through first and second passages 6a, 6b respectively, of a passage system 6 and it is provided to generate such a negative pressure (vacuum) in the respective container 3,4 and in the

passage system 6 that said product 2 is"sucked from" the respective container 3,4 and through one of the passages 6a and 6b respectively, to the vacuum pump 5.

The passage system 6 also includes a third passage 6c through with both passages 6a, 6b communicate with the vacuum pump 5. The product 2 is dispensed therefrom through a tube 7 or a hose or similar provided with a cut-off valve 8.

The dispenser 1 also includes at least one valve device 9 which is adapted for controlling the dispensing such that the vacuum pump 5 first dispenses or dischar- ges the product 2 portionwise from one of the containers 3 or 4 and when this is emptied on its content, dischar- ges the product 2 from the other container 3 or 4. To accomplish this, the valve device is a magnetic valve device 9 which is designed as a permanent magnet device and which has at least three magnet means, namely a first magnet means 9a which is located in a certain definite position at the first passage 6a, a second magnet means 9b which is located in a certain definite position at the second passage 6b and a third magnet means 9c which form part of or is provided in a valve body 9d which is movable between a first valve position LI (shown with solid lines in fig. 2) in the second passage 6b and a second valve position L2 (shown with broken lines in fig. 2) in the first passage 6a. The valve body 9d is adapted to keep the first passage 6a open for transport of the product 2 therethrough and the second passage 6b closed when it is located in the valve position L1. Also, the valve body 9d is adapted to keep the second passage 6b open for transport of the product 2 therethrough and the first passage 6a closed when it is located in the valve posi- tion L2.

By means of the magnetic fields M1 and M2, the mag- net means 9c of the valve body 9d is subjected to retai- ning forces which see to that the valve body 9d remains in its respective valve position L1 or L2 when the va-

cuum pump 5 generates a negative pressure in the open passage 6a or 6b and the container 3 or 4 connected thereto for feeding the product 2 through said open pas- sage 6a or 6b, and this applies as long as the vacuum pump 5 has not emptied the container 3 or 4 in question.

In more detail, each magnetic field MI and M2 respec- tively, may exert retaining forces PI and P2 respective- ly, on the magnet means 9c of the valve body 9d which are greater than the forces trying to displace the valve body 9d from its valve positions L1, L2 due to the fact that a pressure differential is formed on oppo- site sides of the valve body 9d when the vacuum pump 5 generates a negative pressure in the passage 6a or 6b that is open during the transport of the product 2 through said open passage 6a or 6b as long as the con- tainer 3 or 4 in question is not empty.

When the container 3 or 4 from which the vacuum pump 5 feeds the product 2 is empty, the vacuum pump 5 increases the negative pressure therein and in the pas- sage 6a or 6b to which it is connected. Hereby, said pressure differential on opposite sides of the valve body 9d increases until said pressure differential is so great that the valve body 9d is subjected to displace- ment forces F1 and F2 respectively, which are greater than said retaining forces PI and P2 respectively. When this occurs, said displacement forces F1, F2 move or displace the valve body 9d from the present valve posi- tion in a direction towards the other valve position, which means that the passage previously closed for trans- port of the product 2 opens such that the vacuum pump 5 can generate a negative pressure in the previously clo- sed passage for transport of the product 2 out of the second container when the first container is empty.

At the device illustrated in fig. 2, said function is carried through in the following manner: The magnet means 9c of the valve body 9d is retai- ned, by the retaining forces PI generated by the magne-

tic field M2, in the valve position L1 while the vacuum pump 5 is emptying the container 3 on the product 2 and transports or feeds it through the first passage 6a and the third passage 6c (in a direction illustrated with a solid line arrow T1) for dispensing through the tube 7.

When the container 3 is empty and preferably if it is closed against the atmosphere, the vacuum pump 5 in- creases the negative pressure in the first passage 6a, which means that the pressure differential on the down- stream and upstream side of the valve body 9d increases, i. e. the displacement forces F1 increase. When the dis- placement forces F1 are greater than the retaining for- ces P1, the displacement forces F1 will move the valve body 9d from the valve position L1 in a direction to- wards the valve position L2 and at the end of this displacement, the magnet means 9c of the valve body 9d will preferably be attracted by the magnetic field M1 until the valve body 9d is situated in the valve posi- tion L2 in the first passage 6a. In said valve posi- tion L2, it is retained by the retaining forces P2 and in this valve position L2 the valve body 9d is shown with broken lines. Through said movement or displace- ment of the valve body 9d, the second passage 6b is opened, which means that the vacuum pump 5 can generate a negative pressure in said second passage 6b and in the container 4 for transport of the product 2 from said second container 4 after having emptied the first container 3. The product 2 is in said latter case trans- ported from the second passage 6b to the third passage 6c (in a direction illustrated with a broken line arrow T2) and it is then dispensed through the tube 7.

When one of the containers 3 is empty, it can be replaced or exchanged for a container 4 with the product either during dispensing of the product 2 from the con- tainer 4 containing the product or when dispensing or discharge therefrom is not going on.

The relationship between the retaining forces PI

and P2 respectively, and the displacement forces F1 and F2 respectively, is preferably chosen such that the valve body 9d is moved from one valve position L1 to the other valve position L2 or vice versa immediately after the negative pressure increases in a passage 6a or 6b when the vacuum pump 5 has emptied the container 3 or 4 which is connected to said passage 6a or 6b so that no interruption or substantial interruption in the dispensing or discharge occurs when the vacuum pump 5 starts dispensing of the product 2 from the second con- tainer 4 when the first container 3 is empty.

The magnetic valve 9 is preferably provided to generate such a magnetic field MI and M2 respectively, at each valve position L1 and L2 respectively, that when the valve body 9d is moved by the displacement forces F1 and F2 respectively, in a direction towards this mag- netic field M1 and M2 respectively, said magnetic field will attract the valve body 9d in axial direction rela- tive to the respective magnet means 9a, 9b during the last part of its movement such that it sets in the valve position L1 and L2 respectively, at the magnetic field M1 and M2 respectively, attracting the valve body 9d.

Since the magnetic valve device 9 is a permanent magnet device, complex systems for operating the magne- tic valve device are avoided. The three magnet means 9a, 9b and 9c are consequently permanent magnet means. The first two magnet means 9a and 9b are preferably genera- ting a magnetic force, while the third magnet means 9c, consisting or forming part of said valve body 9d, con- sists of a material which is affected by the magnet means 9a, 9b, generating a magnetic force, for genera- ting said two magnetic fields M1 and M2.

The permanent magnet device 9 comprises a valve hou- sing 10 including parts of the first, second and third passages 6a, 6b and 6c, whereby the parts of the first and second passages 6a, 6b preferably are aligned and open into the third passage 6c which is directed per-

pendicular or substantially perpendicular to the two other passages 6a, 6b.

The valve housing 10 defines a first space 11 for the first magnet means 9a which in this case is annular and which has an, in section, circular inner surface 9e which is centered with the part of the first passage 6a situated therewithin and preferably having a circular cross-sectional shape. The valve housing 10 further defines a second space 12 for the second magnet means 9b which in this case is also annular and having an inner surface 9f which in section is circular, said inner surface being centered with the part of the se- cond passage 6b situated within said inner surface and preferably also having a circular cross-sectional shape.

The valve body 9d has in this case a cylindrical sleeve 13 of plastic material or another suitable mate- rial which preferably is non-magnetic. The size and shape of this sleeve 13 are adapted to the size and shape of the passages 6a, 6b such that the sleeve 13 can close the respective passage 6a, 6b when it is situa- ted therein, so that the product 2 can not be brought to pass the sleeve 13 through the closed passage. In the present embodiment, the sleeve 13 has a circular ex- terior and its diameter is adapted to the diameter of the respective passage 6a, 6b such that the sealing therebetween is sufficient but there is no substantial friction when the valve body 9d moves between the valve positions L1 and L2.

The third magnet means 9c is provided inside the sleeve 13 and in the present embodiment it has a circu- lar cross-sectional shape and is centered relative to the inner surfaces 9e and 9f respectively, of the first and second magnet means 9a and 9b respectively, when it is situated in the respective valve position L1 and L2.

It is hereby ensured that the magnetic fields M1, M2 of the magnet means 9a, 9b can hold the valve body 9d in centered valve positions L1 and L2 respectively,

relative to the passages 6a and 6b respectively, which means that the valve body 9d can be brought to"float" in the respective passage 6a, 6b in the respective valve position L1, L2 and it is thereby meant that the valve body 9d has an equally narrow gap around itself within the passage sides or engage eventually with the same hard pressure to the inner sides of the passages.

As is apparent from fig. 1, parts of the passages 6a, 6b and 6c and the first and second space 11,12 may be provided in one and the same unit 14. End pieces 15,16 can be connectable to said unit 14 for closing the spaces 11,12 and preferably for retaining the magnet means 9a, 9b therein. The end pieces 15,16 may have coupling members 17, 18 for connection to the unit 14 and they may include tube members 19,20 for connection thereto of hoses 21,22. These hoses 21,22 are in turn connectable to the containers 3,4.

The magnet means 9a, 9b are preferably designed and mounted such that their retaining forces decrease imme- diately when the valve body 9d is displaced from the respective valve position L1, L2 by the respective dis- placement force F1, F2. Furthermore, the magnet means 9a, 9b may be designed such that they generate magnetic fields M1, M2 which are centered therewith in axial direction, which means that the magnet means 9c of the valve body 9d is subjected to the greatest retaining forces PI and P2 respectively, when the magnet means 9c is situated in positions which are centered with the respective magnet means 9a, 9b. The retaining forces P1 and P2 respectively, may be decreased when required by preventing the valve body 9d from location in said cen- tered positions relative to the respective magnet means 9a, 9b, which means that only a part of the magnetic forces of the magnet means 9a, 9b is utilized. This might be of interest if the displacement forces F1, F2 generated by the vacuum pump 5 are too small relative to the retaining forces PI, P2 of the magnet means 9a, 9b.

The valve body 9d may be prevented from being situa- ted in said centered positions relative to the respec- tive magnet means 9a, 9b by locating an obstacle of some type in the first and second passage 6a, 6b respec- tively. Said obstacles may e. g. by defined by the end pieces 15,16. Such a displaced valve position L1 is shown in fig. 1.

The vacuum pump 5 can be provided to generate a negative pressure from a 30 % vacuum in the passage sys- tem 6 and the respective container 3,4 and the retai- ning forces P1, P2 can be selected such that the valve body 9d can be displaced or moved from its respective valve position L1, L2 at a negative pressure below the abovementioned negative pressure in the open passage 6a and 6b respectively.

The containers 3,4 are preferably sealed against the atmosphere and they are preferably designed such that they can collapse when they are emptied because of the negative pressure generated therein by the vacuum pump 5. The containers 3,4 may e. g. consist of thin- -walled flexible material, e. g. consisting of or inclu- ding plastic, i. e. they may be designed as plastic bags.

As is apparent from fig. 3 and 4, each hose 21,22 may have an outer coupling member 23 and each container 3,4 an inner coupling member 24. The inner coupling member 24 may be located within a sealed wall portion 25 inside the for the rest also completely sealed contai- ner 3,4. The hoses 21 and 22 respectively, can be con- nected to the containers 3 and 4 respectively, by pushing the outer coupling members 23 of said hoses 21,22 through the sealed wall portion 25. The outer coupling member 23 is also pushed into the inner coupling member 24 until it is fixed therein and thereby, the respective contai- ner 3,4 has been opened and the respective hose 21,22 connected thereto such that its product 2 can flow out of the container 3 or 4 and through the coupling mem- bers 24 23 into the respective hose 21,22. It should

be mentioned that coupling devices of this or similar type are known from US 4 603 793 or EP 0 905 045 (= US 6 098 845).

When the first container 3 is empty and the valve body 9d displaced from valve position L1 to valve posi- tion L2, the vacuum pump 5 will be able to empty the second container 4, whereby the product 2 will flow in direction T2 through the second passage 6b. Since the valve body 9d in valve position L2 closes the first passage 6a, the first empty container 3 can be replaced by a full container 3 and this can be done during dis- pensing of the product 2 from the second container 4 or during an interruption of said dispensing or discharge.

When the second container 4 is empty, the valve body 9d will again be brought to leave the valve position L2 and return to valve position L1 such that the empty second container 4 can be exchanged for a full container 4 and so on.

The invention is not limited to the embodiment of the invention described above, but may vary within the scope of the following claims. Thus, it should be men- tioned that instead of the two fixed magnet means 9a, 9b generating magnetic forces, the movable magnet means 9c can generate a magnetic force and the other magnet means 9a, 9b then be affected by said magnetic force.

There may be more than two containers 3,4 and inde- pendent of the number of containers, these may be of other types than those illustrated and described above.

Regarding the product 2 in the containers 3,4 it should be mentioned that it may be liquid or semi-liquid foodstuff such as ketchup, mustard, sauces, drinks or flavours or concentrates thereof. The product 2 however, may also be another product than foodstuff, e. g. clea- ning liquids or concentrates thereof.

When required, containers 3,4 with different pro- ducts 2 may be used instead of containing the same pro- duct.

Finally, it should be mentioned that the valve body 9d, when moving between its valve positions L1, L2, may cooperate with corners 6d, 6e in the passage sys- tem 6 where the passages 6a, 6b from the containers 3, 4 open into the passage 6c connecting said passages 6a, 6b with the vacuum pump 5, such that solid particles included in the product 2 are cut by the valve body 9d in cooperation with said corners 6d, 6e.