REFILLABLE DISPENSER

Abstract: The application describes a dispenser for dispensing a product, comprising a dispenser head (1') through which the product can be dispensed, withdrawal means to assist in the withdrawal of the product from a collapsible container (4') thereof, a substantially rigid container (2') above the dispenser head for holding the collapsible container and piercing means (18) at the base of the first mentioned container to open the collapsible container upon it being placed into the first mentioned container.

Description: PCTTT.T.»RT.T! DISPENSER FIELD OF THE INVENTION The present invention relates to a dispenser, for example for dispensing liquid or slurried products, in particular detergents, wetting agents, drying agents and rinse aids for industrial cleaning processes, typically but not exclusively for dishwashing machines, or for dispensing non-liquid detergents in processes such as machine dishwashing, manual washing of dishes and pans, in commercial kitchens, general cleaning activities, and in laundries. The non-liquid detergents might be in powder, granulate, tablet, briquette or pellet form. By the term "detergents" is meant any chemical product having a cleaning, drying and/or disinfecting property. Although the dispenser is particularly useful for detergents, it can be used for other non-liquid substances such as additives for water treatment, for example to prevent scale. Detergents in dishwashing machines are generally dispensed on an intermittent basis, but the invention is not limited to intermittent dispensing. BACKGROUND OF THE INVENTION Conventionally, liquid detergents are supplied to customers in large drums and the detergent reservoir in the dishwashing machine is regularly filled up from the drums. This is a laborious and inconvenient method of keeping the dishwashing machine topped up and could result in spillage of the liquid, which is often caustic, onto the operator's hands. Alternatively, the detergent may be supplied from a relatively large drum and pumped into the dishwashing machine along a tube or otherwise dispensed directly into the dishwashing machine. Such pumping systems often cause spillage of the detergents when the operator is disconnecting and reconnecting the pumping system to the supply drum. One approach to solving the problems of the conventional liquid dispensing methods is shown in EP-A- 0369722 in the name of Diversey Corporation. With the dispenser described in this publication, a rigid container of liquid is inverted onto a dispensing head. The top of the container is closed by a rubber septum with a slit in it. A penetrating member on the dispensing head penetrates the septum to allow the liquid to be dispensed. Also, US Patent No. 3952918 in the name of Highland Laboratories discloses a dispensing system which includes a puncture tube which pierces a rubber seal on a rigid container of the liquid to be dispensed. Conventional dispensers for non-liquid detergents for dishwashers comprise a container for the detergent into which a nozzle sprays water in a generally vertical direction. The nozzle is typically controlled by a valve connected in an electrical circuit which includes the washing vessel itself. When the concentration of the cleaning agent in the washing vessel falls below a given amount, the valve opens and water is sprayed. When the concentration reaches a sufficiently high level, the valve closes and spraying is stopped. The container may either be a hopper which is refilled as necessary and in which the nozzle is permanently fitted, or may be a cartridge which, when empty, is disposed of and replaced by another full cartridge; in the latter case, the nozzle is mounted beneath the opening of the cartridge. In both cases, the nozzle sprays upwardly and into the powder or granular detergent which is supported above the nozzle by a coarse mesh. These two conventional systems have been used very widely throughout the world for the past fifteen years or more. Between them, they account for the majority of dispensing systems currently in use in industrial washing machines, for example for use in restaurants. Another dispenser for dispensing powder or granular material, for example caustic dishwashing granules, is described in the applicant's US Patent No. 4666682 and European Publication No. 0300819. In this dispenser, an inverted rigid container of the granular material is mounted on a dispenser head which includes spray means to inject a spray of water in a generally horizontal direction into the container. The spray dissolves the granular material falling out of the container and washes it into the washing machine. A disadvantage of the systems in which reservoirs or hoppers are periodically refilled is that it can be awkward to refill the hopper and spillages can easily occur, which is a potential health hazard. A disadvantage of the systems in which rigid containers or cartridges are used is that the cartridges are relatively expensive and so involve a waste of resources if they are not reused. Furthermore, the empty cartridges are bulky and so are inconvenient to handle. In a system sold by the company Henkel in Germany, it is known to place a bag of the powder or granular material in a hopper above a dispenser. The dispenser includes a wire which is moved to cut open the bag. The bag is then shaken to fill the hopper and empty the bag, which is then removed. A disadvantage of this system is that in shaking and removing the bag, the powder or granular material tends to get spilt. This can be a health hazard as well as an inconvenience. An object of the invention is to provide an improved dispenser. SUMMARY OF THE INVENTION Accordingly, the invention provides a dispenser for dispensing a product, comprising a dispenser head through which the product can be dispensed, withdrawal means to assist in the withdrawal of the product from a collapsible container thereof, a substantially rigid container above the dispenser head for holding the collapsible container, piercing means at the base of the first mentioned container to open the collapsible container upon it being placed into the first mentioned container and means for retaining the product in the collapsible container while the withdrawal means assists in the withdrawal of the product. The invention also provides a method of dispensing a product through a dispensing head, comprising the steps of inserting a collapsible container of product into a substantially rigid container above the dispensing head, piercing means being provided at the base of the rigid container whereby the collapsible container is opened as it is lowered in, withdrawing the product from the collapsible container through the dispenser head, and removing the empty collapsible container when all the product has been dispensed. The advantage of the invention is that spillages of product do not occur and all that is left to be disposed of is an empty collapsible container, which is relatively cheap and easily compressed. As used herein, the term "collapsible container" is intended to mean a container which collapses under its own weight when empty or under minimal manual pressure or under atmospheric pressure when its contents have been removed particularly when air cannot enter the container as product is withdrawn. The collapsible container is thus in the nature of a pouch or bag. Where the product is a liquid or a slurried product, the dispenser head can include an outlet connected to a pump for withdrawing the product. The pump is adapted to function as both the means to retain product in the collapsible container and as the withdrawal means to withdraw product. Preferably, the piercing means in this case is an at least partly tapered spike which widens from a point at its uppermost portion. The collapsible container is formed of a material which does not tear easily and has a degree of elasticity. Thus, according to a preferred aspect of the invention, on lowering a full collapsible container into the rigid container, the point of the spike initially punctures the container, the puncture hole then widening as the container is lowered further onto the spike with the walls of the puncture hole preferably sealing around the spike so that there is no leakage of the contents. The spike is at least partly hollow so as to define an outlet passage for the product. Preferably, there is at least one opening in the side of the spike which communicates with a substantially central, axial passage. The absence of an opening at the top of the spike, at or adjacent the point, avoids the possibility of such an opening being blocked either by the collapsible container collapsing onto the point or by a section of the container wall itself at the time it is punctured. Where the product is in non-liquid form, spray means are provided at the dispenser head to spray water onto the product as the withdrawal means. In this case, the piercing means may comprise a plurality of upwardly inclined webs meeting at a point. An imaginary line joining the bottom ends of the webs forms a polygonal shape, preferably a square. The bottom of the rigid container and of the collapsible container substantially match this shape. The advantage of this design of piercing means is that a plurality of triangular sections or flaps are created when the container is pierced and these are pushed downwardly by the material inside to create a full opening in the bottom of the bag. The dispenser head also includes the retaining means, for example a mesh or grid, on which product rests before being dispensed by the spray means. Preferably, the bottom of the collapsible container is formed with a relatively rigid strengthening collar around its base, the shape of the collar conforming, at least substantially, to that of the piercing means. The advantages of the collar are that the flaps of container material tend to fall downwards more certainly, hinging about the sides of the collar. No "shelves" remain inside the container base upon which material, for example in powder form, would otherwise tend to collect. Such collected material would be disadvantageous from both an economic and health point of view when the container came to be replaced, it being not completely empty. In an alternative embodiment for non-liquid products the piercing means is in the form of a substantially conical perforated member. In other words the piercing means is integral with a mesh through which the product is dispensed upon being wetted with the spray. The piercing means is formed in a generally pointed shape so that it and the mesh form a hollow into the middle of which water can be sprayed. BRIEF DESCRIPTION OF THE DRAWINGS Preferred embodiments of the invention are described in detail below, by example only, with reference to the accompanying drawing, wherein: Fig. 1 is a perspective view of a dispenser of the invention into which a collapsible container is being placed; Fig. 2 is a schematic part-elevational and part- sectional view of one embodiment of the dispenser of Fig. l; Figs. 3A, 3B and 3C are schematic sectional views of different piercing members for the dispenser of Fig. 1; Fig. 4 is a schematic part-elevational and part- sectional view of a second embodiment of the dispenser of Fig. 1; Fig. 5A is a schematic perspective view of the piercing member and Fig. 5B is an underside view of the collapsible container; and Fig. 6 is a schematic elevational view of a third embodiment of a dispenser of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The dispenser of Fig. 2, in conjunction with Fig. 1, is intended to dispense liquid or slurried products and comprises a dispenser head 1, a rigid container or hopper 2 and withdrawing means (not shown) . The dispenser head and the withdrawing means can be conventional, for example the retaining means and withdrawing means can in combination be provided by a peristaltic pump; their construction is thus well understood by the man skilled in the art and so will not be described in more detail here. The peristaltic pump, when operating, withdraws liquid through the piercing device; however, when the pump is not operating the liquid is retained .... the dispenser and is not permitted to pass beyond the pump head. In this manner, it is only when the withdrawal means is actuated that dispensing takes place, to provide thereby intermittent dispensing. Arranged above the dispenser head 1 is the hopper 2 which is of substantially rigid design and of any suitable shape and size. The top of the hopper 2 is open, to allow insertion of a collapsible container 4 of the liquid or slurried material to be dispensed. The open top of the hopper has a lid 5. The collapsible container or pouch 4 is constructed so as to have a shape and size corresponding to the shape and size of the hopper 2. The container may be formed of a 0.25 mm thick sheet of low density polyethylene, for example. Other materials could of course also be used, for example laminated polyethylene/nylon or polyethylene/PET, provided that they have good tear resistance and ability to seal about the piercing device. The base or gusset of the container 4 can be formed of a different material than the remainder of the collapsible container, for example a material of a slightly smaller thickness (e. g. 0. 16mm) . It is advantageous for the entire container to be made of the same plastics substance, however, to facilitate recycling. At the base of the hopper 2 is the piercing member 8 which punctures the collapsible container or bag 2. As seen more clearly in Figs. 3A, 3B and 3C, the piercing member 8 consists of an upwardly directed spike 9, with a point 10. The spike 9 can be formed of a rigid plastics material, for example PVC, or of steel. The spike 9 is preferably located at the centre of the base of the hopper 2. This tends to create a maximum piercing force to puncture the flexible container and also tends to equalize horizontal forces around the container; in other words, one side of the container does not tend to pull away more from the spike, which would cause leakage. As seen in Figs. 3A, 3B and 3C, the spike has a tapered shape so that the elastic material of the collapsible container seals efficiently around the enlarged puncture hole. The taper can be constant or can vary between two taper angles. Alternatively, the spike can have a cylindrical body portion below the tapered, pointed portion, as shown in Fig. 3A. The spike has a central hollow bore 11 which connects to the outlet pipe of the dispenser. A transverse passage 12, opening on one or two sides of the spike, communicates with the end of the bore. The spike of Fig. 3C has annular lips 13 which create discrete rings to help prevent either leakage of the product out of the pouch 4 or leakage of air in. The lips 13 also serve to more efficiently anchor the base of the pouch onto the spike. The spike length, i.e. that part which extends above the floor of the hopper, can be approximately 20 mm, with a maximum diameter of 8 mm. These dimensions are, however, only examples. To use the dispenser of Fig. 2, the hopper is opened and a collapsible container or pouch of the desired detergent is lowered in. The weight of the full container forces its bottom part onto the point 10 of the spike 9, thereby puncturing the container. As the container continues to fall to the bottom of the hopper, the puncture hole in the container is widened and seals around the sides of the spike. Due to the pump or other withdrawal means holding back the liquid level in the container, the seal established by the container around the piercing device must be sufficient to withstand the pressure of the head of liquid in the container. The withdrawing means is then operated in a conventional fashion, when required, to dispense the liquid. When the container is empty, it will have collapsed under atmospheric pressure as the contents were pumped out and is simply lifted out and replaced by a full container. The hopper 2 is designed to be removable so that it can easily be cleaned and so that any leakage that might occur, should the collapsible containers be incorrectly lowered in, can easily be disposed of. Ball 14 in the outlet from the dispenser head seals the outlet when the hopper is removed. As an alternative, to deal with possible leakage, should the collapsible container be "double-spiked", a drain hole 1" in the hopper could be provided through which excess liquid could flow away to be disposed of or recycled. The dispenser of Fig. 4, in conjunction with Fig. 1, is intended to dispense non-liquid products, for example powder or granular material, and comprises a dispenser head 1' and spray means 3. The dispenser head and the spray means can be conventional; their construction is thus well understood by the man skilled in the art and so will not be described in more detail here. As in the first embodiment, above the dispenser head 1' is the hopper 2' which is of substantially rigid design and of any suitable shape and size. The top of the hopper 2 opens, to allow insertion of a collapsible container 4" of the powder or granular material to be dispensed. The collapsible container 4' is again constructed so as to have a shape and size corresponding to the shape and size of the hopper 2. The container may be formed of the same materials as in the first embodiment, although it is appreciated that the container, in view of the nature of the contents, could be made from pressed paper suitably coated with wax or plastic to make it impermeable to water. In the dispenser head, below the base of the hopper 2', is a mesh 16 through which the powder or granular material is dispensed upon being impacted by a jet 17' of water coming in through lateral aperture 17. Alternatively, the jet could come vertically upwards, through the mesh. At the base of the hopper 2' is the piercing means 18 which opens the collapsible container or bag 4' . As seen more clearly in Fig. 5A, the piercing means 18 consists of four upwardly inclined webs 19, meeting at a point 20. The webs 19 are formed of a rigid plastics material or of steel and, looking in a downward direction, are relatively narrow to provide maximum area for the powder or granular material to pass through. An imaginary line joining the lower ends of the webs 19 forms a polygonal shape, here a square. In this embodiment, the base of the hopper 2' is formed to a complementary square shape. By virtue of their narrowness, and/or because they have a sharpened edge, the webs pierce the base of the container 4' in an "X" shape, matching the arrangement of the webs. The four sections of container material making up the square shape across which the X-shaped cuts are formed tend to bend downwardly with the weight of the material in the container to create a large and effective opening. As shown most clearly in Fig. 5B, a relatively rigid collar 21 of a suitable plastics material is fitted into the bottom of the container 4' with a section of plastics sheet material stretched across it. For example, the collar can be made by injection molding from a high density polyethylene/low density polyethylene mix and can be heat welded into the bottom of the container. The shape of the collar 21 corresponds to that of the imaginary line joining the bottom ends of the webs 19. It will be appreciated that, upon being pierced, the triangular sections of container material within the collar tend to pivot downwardly about the sides of the collar, which leaves no "shelves" inside the container base upon which the material inside could collect. The material inside the collar can be the same as the remaining material of the container, stretched relatively tightly across the collar, or can be a thinner material - such as polyethylene, PET, polypropylene or nylon - to make piercing even easier. In particular, the membrane inside the collar can be formed of low density polyethylene of a thickness of between 0.05 and 0.10 mm. The number of webs can be more or less than four, three of course being the minimum. With three webs, the shape of the collar is triangular and with five it is pentagonal. Above five, there is a problem that the number of webs can begin to impede the passage of the powder or granular material. To use the dispenser of Fig. 4, the hopper is opened and a collapsible container or pouch of the desired detergent is lowered in. The weight of the full container forces its bottom part onto the point 20 of the webs 19, thereby rupturing the container. As the container continues to fall to the bottom of the hopper, the opening in the container is widened to form four triangular flaps which fall downwardly along the collar edges. The spray means 3 is then operated in a conventional fashion, when required, to dispense the detergent. When the container is empty, the water spray having rinsed the container to completely empty it, it is simply lifted out, discarded and replaced by a full container. The dispenser of Figure 6 is again intended to dispense non-liquid products; it is similar to the dispenser of Fig. 4 except that a substantially vertical spray means 3' is used, instead of a substantially horizontal spray. The collapsible container is essentially the same as in the earlier embodiments. At the base of the hopper 2" is arranged a rigid mesh 24 which can support the powder or granular material above the spray of water, as in the prior art systems described at the beginning of this application. The mesh 24 is shaped so as to define a point or other shape which will tend to pierce, rupture or tear the collapsible container inside the hopper. In the illustrated embodiment, the mesh is substantially conical, with four main ribs 25 meeting at point 26. If desired, the base portion of the container which is to be broken by the point of the mesh could be formed as a discrete membrane bonded to the remainder of the container material possibly inside a rigid collar, as in the previous embodiment. The membrane could thus be formed of a material which is easier to tear than the material of the container, e.g. thinner polyethylene, PET, polypropylene or nylon. As an alternative, it is also appreciated that the membrane could be made of an impermeable pressed paper which is readily severed by the piercing device. In view of the pressure sensitive nature of the membrane, it is understood that a protective cap or the like might be press-fitted onto the collar 21 to protect the membrane until removed to expose the membrane for puncture when placed in the dispensing head. To use the dispenser of Fig. 6, the hopper is opened and a collapsible container or pouch of the desired detergent is lowered in. The weight of the full container forces its bottom part onto the point 26 of the mesh 24, thereby rupturing the container. As the container continues to fall to the bottom of the hopper, the opening in the container is widened so that the contents are exposed over the full extent of the mesh. The spray means 3 is then operated in a conventional fashion, when required, to dispense the detergent using a vertical jet of water. The hollow shape of the mesh is advantageous in that a greater area of detergent is exposed to the water spray. As before, when the container is empty, the water spray having rinsed the container to completely empty it, it is simply lifted out and replaced by a full container. Although preferred embodiments of the invention are described herein in detail, it will be understood by those skilled in the art that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.

Claims: CLAIMS 1. A dispenser for dispensing a product, comprising a dispenser head through which the product can be dispensed, withdrawal means to assist in the withdrawal of the product from a collapsible container thereof, a substantially rigid container above the dispenser head for holding the collapsible container, piercing means at the base of the first mentioned container to open the collapsible container upon it being placed into the first mentioned container and means for retaining the product in the collapsible container while the withdrawal means assists in the withdrawal of the product. 2. A dispenser according to claim 1, for dispensing liquid or slurried products, wherein the piercing means is a hollow spike. 3. A dispenser according to claim 1, for dispensing non- liquid products, wherein the piercing means is adapted to open the bottom of the collapsible container to allow the product to fall out and wherein spray means are provided to wet the product as it falls out. 4. A dispenser according to claim 3, wherein the piercing means comprises a substantially conical perforated member having an upwardly projecting piercing means for piercing a collapsible container. 5. A dispenser according to claim 2, wherein said hollow spike comprises a piercing member and transverse extending passages below said piercing member. 6. A dispenser according to claim 2, wherein said hollow spike comprises an outwardly tapered shaft member to enhance a seal with a pierced collapsible container. 7. A dispenser according to claim 3, wherein said piercing means comprises a plurality of inclined cutting edges which intersect to form an apex, said cutting edges severing a collapsible container wall to release the non- liquid products. 8. A dispenser according to claim 7, wherein said non- liquid product is granular solid detergent, said cutting edges forming an opening permitting solid material to drop downwardly onto said retaining means. 9. A dispenser according to claim 8, wherein said retaining means is a mesh screen. 10. A method of dispensing a product through a dispensing head, comprising the steps of inserting a collapsible container of product into a substantially rigid container above the dispensing head, piercing means being provided at the base of the rigid container whereby the collapsible container is opened as it is lowered in, withdrawing the product from the collapsible container through the dispenser head, and removing the empty collapsible container when all the product has been dispensed.

Inventors: BIRD KENNETH JOHN HERBERT, CROSSDALE GARRY WILLIAM, VEVERIS MICHAEL, WEBB JOHN CHRISTOPHER, BIRD, KENNETH, JOHN, HERBERT, CROSSDALE, GARRY, WILLIAM, VEVERIS, MICHAEL, WEBB, JOHN, CHRISTOPHER
Applicants: BIRD KENNETH J H, BIRD KENNETH JOHN HERBERT, DIVERSEY CORP, VEVERIS MICHAEL, WEBB JOHN CHRISTOPHER, BIRD, KENNETH, JOHN, HERBERT, CROSSDALE, GARRY, WILLIAM, DIVERSEY CORPORATION, VEVERIS, MICHAEL, WEBB, JOHN, CHRISTOPHER
Application year: 1995
Main classification: A47L15
IPC codes: A47L15, B01F1, D06F39