Dispensing Apparatus

Abstract: A dispensing apparatus for dispensing a product from a container (600) under pressure of a propellant by means of a composite piston (138). The apparatus has a valve (701) operated by means of an actuator (702) and a lever (630). The actuator co-operates with the valve and lever by means of a screw thread arrangement, such that turning the actuator relative to the lever varies the flow rate of product out of the apparatus. The valve is held in place by a retaining member (715) provided with an internal thread. An actuator (702) fits over the retaining member (715) and is rotationally coupled to the retaining member (715) by ribs (716,717). No boss is required to fit the valve assembly to the container (600), making the filling and assembly of the can simpler.

Description: This invention relates to dispensing apparatus. Particularly, but not exclusively it relates to dispensing apparatus for dispensing viscous materials from a container under pressure of a propellant. Known dispensing apparatus commonly includes a valve mechanism fitted to a container which is refilled with a product, for example mastic or sealant, which is to be dispensed. Examples are disclosed in Patent document EP-B-0243393 (Rocep Lusol Holdings Limited). However, known arrangements have several disadvantages. For example, the cost of components used in the manufacture of such known apparatus is high. This is particularly true in relation to the cans used as containers in such apparatus. Further, automatic assembly of such apparatus is complicated and costly. Yet another disadvantage is that the product must be filled into the dispensing apparatus during manufacture of the apparatus. This involves the product manufacturer supplying the product in bulk to the apparatus manufacturer who then returns the filled apparatus to the product manufacturer for sale. This is costly and inconvenient. As a result of the foregoing, the overall costs associated with presently available dispensing apparatus are high. It would also be desirable to have dispensing apparatus such that a manufacturer can fill the apparatus with product himself, after the apparatus has been assembled and/or pressurised, and to have dispensing apparatus which is refillable. GB A 1 445 202 discloses a dispensing apparatus with an actuator which, when operated, causes a piston to move down and open a valve, causing pressurised product to flow through an exit orifice. However it is not possible to lock the apparatus to prevent accidental operation of the actuator. According to the present invention there is provided dispensing apparatus for dispensing a product from a container (600) under pressure of a propellant, said apparatus comprising a product chamber within the container and a valve assembly adjacent to the product chamber, the product chamber containing a piston (138) situated between the propellant and the valve assembly, characterised in that the valve assembly comprises: a cap (700) secured to the container and provided with a central aperture, a valve (701) slideably movable within the central aperture between a lower open position in which product can flow through ports into the valve and an upper closed position in which the ports are closed, the valve having a protruding portion extending above the cap (700) and provided with an external thread, a retaining member (715) provided with an internal thread screwed around the protruding portion to hold the valve (701) in place in the cap in a "lock-off" position in which sliding movement of the valve is prevented, the retaining member having an external surface provided with longitudinal ribs (716), and an actuator (702) positioned over the retaining member, the actuator having an internal surface provided with longitudinal ribs (717), such that the actuator (702) and retaining member (715) are rotationally coupled such that rotation of the actuator causes the retaining member to travel up the protruding portion of the valve thereby allowing the valve (701) to be moved from the upper closed position to the lower open position; the apparatus further comprising a lever (630) adapted to open the valve (701) by pushing the actuator and valve down relative to the cap. Preferably, the piston is an interlocking double piston. The interlocking sections preferably have a sealant between them. The sealant forms a substantially impenetrable barrier between the propellant and the product. The lever may be manufactured of plastics material; it may be manufactured as a single piece of plastic; for example by injection moulding. Preferably, the actuator and the lever co-operate by means of a screw thread arrangement. Turning of the actuator relative to the lever may vary the flow rate of product out of the apparatus. Turning may be possible from a "lock-off" position, in which the actuator is clicked home, to a fully on position. Markings may be provided to show the flow rate corresponding to predetermined positions on the lever. Means may be provided to demonstrate to a user that the actuator is in the closed position, ie the position in which no product can flow. It is further preferred that the actuator is provided with means to limit the travel of the actuator once the fully open position is reached. Said means may also prevent the actuator from being opened too far or being completely removed from the apparatus. Said means may be a groove or substantially axial slot in the external wall of the actuator. Preferably, the container is made substantially from tin plate or aluminium. Most preferably the container is a wall ironed tin plate can. For example, it may be an extruded tin plate can as used in the beverage industry, without a side seam. Specific embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig 1 is a view in cross-section of a dispensing apparatus not in accordance with the present invention; Fig 2 is an enlarged view of the valve assembly of the dispensing apparatus of Fig 1; Fig 3 is a view in cross-section of the nozzle end of apparatus in accordance with an embodiment of the present invention; and Figs 4a and 4b are exploded views in cross-section of the nozzle end of apparatus in accordance with a further embodiment of the present invention. Referring firstly to Fig 1 of the accompanying drawings, apparatus in accordance with an embodiment of the present invention will be described. The apparatus will be referred to hereinafter as a "pressure pack" or "pack". The pressure pack of Fig 1 is generally denoted 100. The pack 100 consists generally of a canister section and a valve section. In this example, the canister section comprises a standard preformed cylindrical can 102 which is internally lacquered. It is envisaged that the can 102 could be a tin plate beverage can having a bore in the top. Alternatively the can 102 could be manufactured from aluminium. The valve portion 104 is a substantially hollow cylindrical tube, provided with a screw thread 110 on its exterior surface. The valve portion 104 is open at one end (the top as viewed in Fig 2) and has a flap valve 112 attached to its other end by means of a rivet 114. The valve portion 104 is also provided with, in this example, four ports 116 around its exterior surface adjacent the screw thread 110 (to the bottom of the screw thread 110 as viewed in Fig 2). It should be noted at this stage that the flap valve 112 is made from a rubber disc which preferably naturally lies in the open position (ie not sealing the end of the valve). This allows air to be expelled out of the pack, through the valve, during pressurisation. The flap valve 112 is shown in the closed position in Figs 1 and 2. It should further be noted that the total area of the ports 116 exceeds the cross-sectional area of the valve portion 104 itself. The boss 106 is a substantially hollow cylinder with a large flange portion 118 at one end. The valve portion 104 fits snugly within the hollow of the boss 106. The valve portion 104 is fitted into the boss 106 open-end-first and is prevented from moving too far up the boss 106 by abutment of the shaped end profile 120 of the valve portion against a corresponding portion 122 of the boss 106. This can be seen in Fig 2. Further, the valve portion 104 may be prevented from falling out of the boss 106 by means of a clip 124 on the exterior of the valve portion 104 which interacts with a slot (not shown) in the interior surface of the boss 106. It should be emphasised, however, that this is an entirely optional feature. The actuator 108 is a moulded plastic component having a hollow cylindrical interior and a stepped exterior surface. A screw thread 126 is provided on the interior surface of the actuator 108. Following insertion of the valve portion 104 into the boss 106 (and clicking into place) the actuator 108 is placed over the end of the valve portion 104 and screwed onto it by means of cooperation of screw threads 110 and 126. (An optional spring 128 may be dropped into a groove 130 provided in the boss 106 prior to fitting the actuator 108. The spring 128 is designed to close the valve if this does not happen automatically, as will be explained later.) Screwing on the actuator 108 completes the sub-assembly. Referring again to Figs 1 and 2, the sub-assembly is then inserted up the inside of the can 102 until the flange 118 provided on the boss 106 fits into a curled lip 136 at the top of the can 102. This limits further movement of the boss 106. The boss 106 should be a friction fit within the can 102, thereby sealing the end of the can 102. However, if necessary the neck of the can 102 may be crimped below the boss 106 to hold the sub-assembly in place. Following insertion of the sub-assembly, a double piston assembly 138 is inserted into the can 102. The piston assembly 138 comprises two interlocking plastic cup sections 140a,b, each having a stem portion 142a,b in its centre. The cup sections 140a,b lock together and a cavity or chamber 144 is formed between them. In general, the apparatus already described includes a boss portion which is inserted up the middle of the empty canister with the valve assembly therein. However, it is possible to mount the valve assembly on the top end of a canister by means of a specially adapted mounting cap. An example of the mounting cap 300 can be seen in Fig 3. The valve 601 is mounted in the cap 600 and an actuator 602 fitted to the valve 601 in a similar manner to that previously described. An optional support component 603 may be provided as can be seen on the right hand side of Fig 3. Alternatively, the support component is not provided, and the cap 600 continues upwards to form a sleeve 604 surrounding the entry valve 601 to the underside of the actuator 602, as can be seen on the left hand side of Fig 3. A spring 605 is also provided (the benefits of which have already been discussed with reference to other drawings) which at one end sits within a recess 606 provided in the actuator. The entire valve/actuator/mounting cap assembly is then lowered onto the top of a canister 607 (in this case a two piece aerosol can) and crimped over the top, by crimping a curled lip 608 provided on the cap 600 around the outside of the top rim 609 of the can. The top rim 609 is typically a circular rim 1 inch (25.4 mm) in diameter, of the sort generally known in the art. The can 600 could alternatively be a three-piece aerosol can (with sealing dome) or any known aerosol with a hole provided in the top. Alternatively the can 600 may be a one piece can formed with tapering sides which narrow towards the circular rim, which is typically 1 inch or 25.4 mm in diameter. The valve assembly in this example is modified from those of earlier described embodiments. A nozzle 610 with end cap 611 is fitted to the valve 601 by means of a screw thread 620 of increased length, for greater strength. The nozzle 610 is not directly connected to the actuator 602. This assembly has advantages over those already described, for example as the nozzle is tightened onto the valve, this does not cause the valve to open and so no product weeps out of the end of the nozzle. Other components shown in Fig 3 are similar to those already described. It should be noted that the plastic lever 630 already described could be replaced by a more simple lever arrangement, for example a conventional wire lever could be used. The container is filled in the following manner. First the composite piston is inserted into the can while the top of the can is open and lip 621 is flared outwardly to aid insertion of the piston. Then the can is closed to form a one inch (25.4 mm) hole, either by fitting top piece 622 or by forming the can to a taper. The can is then filled with the product from the top. Then the valve assembly comprising the valve 601, actuator 602, nozzle 610, cap 600 and lever is fixed to the top rim 609 by crimping the curled lip 608. The anti-tamper tab 640 comprises a planar piece of plastic connected to the lever 630 which engages one of the eight flutes 642 provided on the valve actuator. The tab 640 is broken off prior to screwing on the nozzle 610 and the first turning of the actuator, to allow for normal use of the pack. Another advantage of the embodiment of Fig 3 is that no boss is required to fit the valve assembly. This means that the ultimate capacity of the can can be greater than with the other described embodiments, and the overall appearance of the pack is not substantially affected. Figs 4a and 4b show exploded views of an embodiment similar to that of Fig 3. Before fixing the valve assembly to the canister, the valve assembly is assembled by inserting the valve 701 into the cap 700 from below, and then screwing a retaining member 715 provided with an internal thread onto the external thread on the protruding portion of the valve 701 in order to hold the valve in place. The external surface of the retaining member 715 is provided with longitudinal ribs 716. The actuator 702 is provided with corresponding internal ribs 717. When the actuator 702 is placed over the retaining member 715 the ribs 716, 717 engage with each other so that the actuator 702 and the retaining member 715 are rotationally coupled. A detent portion 718 on the external surface of the retaining member 715 engages with a corresponding recessed groove 719 on the inner surface of the actuator 702, to hold the actuator 702 on the retaining member 715. The nozzle 710 and end cap 711 are screwed to the valve 701, in a similar way to the embodiment of Fig 3. The cap may be provided with a hinge portion 720 for use with a conventional wire lever to control the valve operation. Alternatively the cap may be used with a moulded plastic lever. It is to be understood that the containers according to the invention may be filled from the bottom, if required, by providing a separate domed base which is sealed to the container after insertion of the product and the composite piston. The packs described have significant advantages over and above known packs including that they may be filled and refilled by manufacturers or retailers on their own premises from bulk quantities of product, instead of sending product to be filled into the packs during manufacture. This means that product-filled packs are much cheaper and easier to produce. The packs themselves are also much cheaper and easier to produce. Modifications and improvements may be made to the foregoing without departing from the scope of the invention.

Claims: Dispensing apparatus for dispensing a product from a container (600) under pressure of a propellant, said apparatus comprising a product chamber within the container and a valve assembly adjacent to the product chamber, the product chamber containing a piston (138) situated between the propellant and the valve assembly, characterised in that the valve assembly comprises: a cap (700) secured to the container and provided with a central aperture, a valve (701) slideably movable within the central aperture between a lower open position in which product can flow through ports into the valve and an upper closed position in which the ports are closed, the valve having a protruding portion extending above the cap (700) and provided with an external thread, a retaining member (715) provided with an internal thread screwed around the protruding portion to hold the valve (701) in place in the cap in a "lock-off" position in which sliding movement of the valve is prevented, the retaining member having an external surface provided with longitudinal ribs (716), and an actuator (702) positioned over the retaining member, the actuator having an internal surface provided with longitudinal ribs (717), such that the actuator (702) and retaining member (715) are rotationally coupled such that rotation of the actuator causes the retaining member to travel up the protruding portion of the valve thereby allowing the valve (701) to be moved from the upper closed position to the lower open position; the apparatus further comprising a lever (630) adapted to open the valve (701) by pushing the actuator and valve down relative to the cap. Dispensing apparatus according to Claim 1, wherein said valve (701) comprises a substantially hollow cylindrical tube having a first upper end and a second lower end, wherein the tube is open at the first end and has one or more ports arranged around the circumference of the tube adjacent to the second end. Dispensing apparatus according to Claim 2, wherein the area of said ports is greater than the cross-sectional area of said cylindrical tube. Dispensing apparatus according to either one of Claims 2 to 3, wherein the second end of said cylinder is closed. Dispensing apparatus according to any preceding Claim, wherein said valve (701) is located within said cap (700) such that said valve can slide longitudinally within said cap, said valve being provided with a shaped end profile at said second end adapted to abut a corresponding portion of the cap to close said valve. Dispensing apparatus according to any preceding Claim, wherein said container (600) is provided with a circular aperture having a rim (609), wherein said cap is adapted to fit to said circular aperture. Dispensing apparatus according to Claim 6, wherein said cap comprises a curled lip portion (608) adapted to be secured to the rim (609) of said circular aperture. Dispensing apparatus according to any preceding Claim, wherein the actuator (702) and the lever (630) co-operate by means of a screw thread arrangement, such that turning of the actuator relative to the lever varies the flow rate of product out of the apparatus. Dispensing apparatus according to Claim 8, wherein the actuator (702) is adapted to be turned between a "lock-off" position in which operation of the lever does not cause the valve to be opened, and a fully on position, in which operation of the lever causes the valve to be opened to produce a maximum flow rate of product. Dispensing apparatus according to any preceding Claim, wherein the container is made substantially from tin plate or aluminium.

Inventors: FRUTIN BERNARD DEREK, FRUTIN, BERNARD DEREK
Applicants: ROCEP LUSOL HOLDINGS, ROCEP LUSOL HOLDINGS LIMITED
Application year: 1998
Main classification: B65D83
IPC codes: B65D83