Patent Document

This application is a division of Ser. No. 10/169,290 filed Aug. 13, 2002; now U.S. Pat. No. 6,685,064 which is a 371 of PCT/GB00/04967 filed Dec. 22, 2000. 
    
    
     FIELD OF THE INVENTION 
     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. 
     BACKGROUND OF THE INVENTION 
     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. The valve mechanism comprises a large number of separate parts which must be assembled together. Automatic assembly of such apparatus is complicated and costly. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a dispensing apparatus which overcomes one or more of the above disadvantages. 
     According to the present invention there is provided a dispensing apparatus for dispensing a product from a container, said apparatus comprising: 
     a product chamber within the container; 
     a valve adjacent to the product chamber; 
     a hinge assembly; 
     a lever hingedly attached to the hinge assembly and having a bearing portion; and 
     a nozzle assembly sealingly engageable with the hinge assembly, the nozzle assembly being rotatable between open and closed positions and including an actuator portion provided with a cam surface which cooperates with the lever bearing portion such that in the open position operation of the lever causes movement of the actuator portion to open the valve and permit flow of the product out of the apparatus. 
     Preferably the apparatus comprises means for urging the product from the product chamber. Preferably the product chamber is pressurised. The product chamber may contain a propellant. The product chamber may contain a piston, situated between the propellant and the valve. 
     Preferably the valve is a tilt valve. Tilt valves are generally known in dispensing apparatus and operate by tilting of a hollow central stem which is resiliently held on a mounting cup by a rubber grommet. The stem is closed at its lower end by a sealing plate. When the stem is tilted, the seal between the grommet and the sealing plate is broken and the product can reach apertures in the central stem and thence flow along the hollow stem. 
     Preferably the valve comprises a mounting cup adapted to secure the valve to the container. Preferably the container is provided with a rolled flange portion and the mounting cup is provided with a corresponding flange portion adapted to engage with the rolled flange portion of the container. 
     Preferably the actuator portion comprises a ring member arranged at a lower end of the nozzle assembly. Preferably the cam surface comprises one or more depressions and one or more raised surfaces. Preferably when the nozzle assembly is in the closed position the lever bearing portion is adapted to bear upon one of said depressions, and when the nozzle assembly is in the open position the lever bearing portion is adapted to bear upon one of said raised surfaces. 
     Preferably the lever comprises two lever bearing portions arranged at opposite sides of the valve. Preferably the cam surface comprises two depressions arranged at opposite sides of the ring and two raised surfaces arranged between the depressions at opposite sides of the ring. 
     Preferably the nozzle assembly is provided with means to limit the rotational travel of the nozzle assembly between the closed position and the open position. These means may comprise two end stops provided on the nozzle assembly adapted to locate against an upstand on the hinge assembly. 
     The nozzle assembly may be provided with fin members adapted to hold the lever bearing portion against the cam surface. The fin members may be of different lengths. Preferably a fin member is provided at each depression and each raised surface of the cam surface, spaced from the cam surface to allow the insertion of the lever bearing portion between the fin member and the cam surface. 
     Preferably the nozzle assembly comprises one or more dog teeth and the hinge assembly comprises one or more slots, adapted such that a dog tooth can enter a slot only when the nozzle assembly is in the open position. The nozzle assembly is preferably coupled to the valve stem for longitudinal movement, such that movement of the nozzle assembly towards the container causes the dog tooth to enter the slot and the valve stem to move, thereby opening the valve to release the product. 
     Preferably, the container is made substantially from aluminium and is most preferably an aluminium monoblock container. Alternatively the container may be a wall ironed tin plate can, or an extruded tin plate can as used in the beverage industry, without a side seam. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Specific embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: 
     FIGS.  1 ( a ) and  1 ( b ) are a side view in cross-section and an end view respectively of a dispensing apparatus in accordance with an embodiment of the present invention in a closed position; 
     FIGS.  2 ( a ) and  2 ( b ) are a side view in cross-section and an end view respectively of the dispensing apparatus of FIGS.  1 ( a ) and  1 ( b ) in an open position with the valve closed; 
     FIGS.  3 ( a ) and  3 ( b ) are a side view in cross-section and an end view respectively of the dispensing apparatus of FIGS.  1 ( a ) and  1 ( b ) in an open position with the valve open; 
     FIG. 4 is an enlarged view of the valve area of the apparatus of FIG.  1 ( a ); 
     FIG. 5 is an enlarged view of the valve area of the apparatus of FIG.  2 ( a ); 
     FIG. 6 is an enlarged view of the valve area of the apparatus of FIG.  3 ( a ); 
     FIGS.  7 ( a ),  7 ( b ),  7 ( c ) and  7 ( d ) are sectional views of the valve, nozzle end cap, lever and hinge assembly respectively of the apparatus of FIG.  1 ( a ); 
     FIG.  7 ( e ) is an end view on the hinge assembly of FIG.  7 ( d ); 
     FIGS.  7 ( f ),  7 ( g ) and  7 ( h ) are a bottom view, side view and top view respectively of the nozzle assembly of the apparatus of FIG.  1 ( a ); and 
     FIGS.  8 ( a ),  8 ( b ) and  8 ( c ) are a bottom view, sectional side view and front view respectively of a hinge assembly of an apparatus according to a second embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1 to  7  of the accompanying drawings, an 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 FIGS. 1 to  3  is generally denoted  10 . 
     The pack  10  consists generally of a canister section and a valve section. 
     In this example, the canister section  12  comprises an aluminium monoblock container of the sort widely used in aerosol applications. It is envisaged that the can  12  could be of tin plate, steel or any conventional can construction having a standard one inch (25 mm) hole in the top. The can may be internally lacquered. 
     The pack  10  is automatically assembled as follows. Firstly a sub-assembly is formed from a valve  14 , a hinge assembly  16 , a lever  18  and an actuating nozzle  20 . The valve is a tilt valve of the type widely used in pressurised dispensers and operated by tilting the valve stem  30 . The valve stem  30  is a hollow plastic tube with apertures  32  in the tube wall at the lower end. The upper end  34  is open, while the lower end is closed by a plastic sealing disc  36 . A resilient grommet  38  of rubber or synthetic material surrounds the lower portion of the stem  30  and is held in place by the sealing disc  36  and a retaining collar  31  formed on the outside of the stem  30 . 
     The grommet  38  is provided with a circumferential groove  40  and a sealing web  42  which house a mounting cup  44  of metal. The mounting cup has an inner flange  46 , which sits sealingly inside the groove  40  on the grommet, and an outer flange  48  which is adapted to fit around a rolled flange  13  which extends around the opening of the container  12 . When the stem  20  is pushed in the direction of arrow A relative to the mounting cup  44 , the sealing disc  36  is pushed away from the grommet  38 , and material in the canister  12  is free to pass between the sealing disc  36  and grommet  38 , through the apertures  32 , along the inner bore of the stem  30  and through the open end  34  of the stem. When the stem is released, the resilience of the grommet  38  pushes the stem back in a direction opposite to arrow A and seals the valve again. If the stem is pushed to one side in the direction of arrow B, one side of the sealing disc  36  is pushed away from the grommet  38 , and material in the canister  12  is again free to pass between one side of the sealing disc  36  and grommet  38 , through the apertures  32 , and out of the stem  30 . 
     The hinge assembly can be seen more clearly in FIGS.  7 ( d ) and  7 ( e ). The hinge assembly  16  is moulded from plastic and comprises a ring  60  having a central aperture  62 . The ring  60  is provided with a circumferential groove  64  adapted to snap on to the outer flange  48  of the mounting cup. A discontinuous flange  66  projects into the aperture  64 , forming two slots  68 , whose purpose is explained later. An upstand  70  is provided with a through bore  72  adapted to house the ends of a wire lever  18 , thereby forming a hinge for the lever. The lever  18  comprises a handle  102 , which extends along the side of the canister  12 , and a lever arm  104 . The lever  18  is preferably formed from a single piece of wire, whose two free ends are mounted in opposite sides of the upstand  70 . 
     The nozzle assembly  20  comprises an elongate tapering nozzle  80  with a removable end cap  82 , which may be click-fit, screw-fit or simple taper fit. The nozzle assembly is free to rotate about its longitudinal axis relative to the hinge assembly  16  and lever  18 . 
     In the illustrated embodiment of FIGS. 1 to  7  the rotation is limited by two end stops  84   a  and  84   b , which come into contact with bevelled contact surfaces  74   a  and  74   b  formed on the upstand  70  of the hinge assembly  16 . When end stop  84   a  is in contact with surface  74   a , the nozzle is in the closed position. When the nozzle is rotated by 45° in a counter-clockwise direction, so that end stop  84   b  is in contact with surface  74   b , then the nozzle is in the open position. 
     When the dispenser is transported and is stored before first use, a removable tab  86  attached to the base  90  of the nozzle assembly prevents any rotation of the nozzle from the closed position by bearing on contact surface  74   b  on the upstand  70 . Only after removal of the tab, by folding and snapping or tearing, can the nozzle be rotated in a counter-clockwise direction. It is to be understood that the provision of a locking tab  86  is optional, and the invention may function without a locking tab. 
     The nozzle assembly is provided with four fins, two shorter fins  92  and two longer fins  94 . The base  90  of the nozzle serves as an actuator to control the opening of the valve and is provided with a cam surface which has two depressions  98  adjacent to the longer fins  94  and two raised surfaces  96  adjacent to the shorter fins  92 . The lever arm  104  of the lever  18  has a bearing portion  100  which is adapted to fit between the longer fin  94  and the depression  98  when the nozzle assembly is in the closed position. Upon rotation of the nozzle assembly, the longer fin moves away from the bearing portion  100 , so that the bearing portion  100  is free to rise, and the cam surface pushes the bearing portion up until it is raised to the level of the raised surface  96 , where it is held between the shorter fin  92  and the raised surface  96 . 
     As the bearing portion  100  is raised, the handle  102  on the lever  18  is moved away from the side of the canister  12 , from the position shown in FIG.  1 ( a ) to that shown in FIG.  1 ( b ). 
     In an alternative embodiment of the invention, not illustrated, the end stops on the nozzle assembly are omitted. The nozzle assembly is provided with an internal thread which mates with an external thread on the valve stem  30 . The nozzle assembly is secured to the valve stem by turning in a clockwise direction until the shoulder  120  on the inside of the nozzle bears on the collar  31  on the outside of the valve stem. Further rotation of the nozzle assembly in a clockwise direction causes both the nozzle assembly  20  and the valve stem  30  to rotate together relative to the grommet  38  and can  12 . The base of the nozzle has a cam surface, as described previously, but the nozzle assembly does not stop automatically when the open position is reached. A first rotation in the clockwise direction brings the nozzle to the open position, while further rotation in the clockwise direction brings it back to the closed position, and so on. 
     Referring again to FIGS. 1 to  7 , the base  90  of the nozzle is provided with a cylindrical extension  110  which has an internal diameter adapted to fit slidably around the inner flange  46  of the mounting cup  44 . The inner surface of the cylindrical extension  110  engages with a protruding part  41  of the grommet  38  adjacent to the groove  40 , to form a seal which prevents the product passing between the valve  14  and the nozzle  80 . 
     Arranged outside the extension  110  are two dogs  112 , which in the closed position of the nozzle are aligned on top of the flange  66  in the hinge assembly. In this position the nozzle assembly  20  cannot be moved in the direction of arrow A relative to the hinge assembly  16 , because the dogs  112  will interfere with the flange  66 . However, when the nozzle is rotated to the open position the dogs  112  are aligned with the slots  68  formed by the gaps in the flange  66 , and the nozzle assembly  20  can be moved in the direction of arrow A, so that the dogs  112  enter the slots  68 . 
     It is to be understood that the nozzle assembly may be provided with only one dog  112 , and the hinge assembly with only one slot  68 . 
     When the nozzle assembly is in the open position, as in FIGS. 2 and 3, then depression of the handle  102  towards the canister  12  causes the bearing portion  100  of the lever  18  to push the nozzle assembly  20  in the direction of arrow A towards the hinge assembly  16 . The nozzle assembly is linked to the valve stem  30  to prevent relative longitudinal movement of the valve  14  and nozzle  80 . The linking means may comprise a thread or a rib and groove arrangement. In the example of FIGS. 4 to  6  three seals  140  are provided on the outer bore of the valve stein  30 . These seals  140  seal between the valve stem  30  and the nozzle  80  and prevent product being forced back down between the valve stem  30  and nozzle  80  by back pressure in the nozzle  80 . 
     An alternative method of sealing is shown in FIG. 7, in which the inside of the nozzle  80  is provided with an annular projection  114  which seals between the nozzle  80  and the valve stem  30  to prevent any product passing between the nozzle  80  and the valve stem  30 . An external thread  116  is provided on the valve stem  30  which engages with a corresponding internal thread (not shown) on the nozzle  80  to prevent relative longitudinal movement of the valve  14  and nozzle  80 . 
     As can be seen in FIG. 6, a shoulder  120  on the inside of the nozzle  20  bears on the collar  31  on the outside of the valve stem  30  and pushes the valve stem against the resilience of the grommet  38  in the direction of Arrow A. This causes the disc  36  to move away from the grommet and allow product to be expelled under pressure from the canister through the nozzle  80 . 
     The nozzle assembly  20  is a single moulded piece of plastic. The nozzle assembly  20 , the hinge assembly  16  and the lever  18  can be preassembled to form a complete nozzle/hinge sub-assembly and then secured to the canister  12  during the filling process. The nozzle/hinge sub-assembly of the invention is much simpler and cheaper than prior art sub-assemblies, because it uses only three components. The valve, being an off the shelf tilt valve having only three parts, namely the stem  30 , grommet  38  and mounting cup  44 , may be obtained cheaply and easily. In practice the container is filled, the valve  14  is secured to the container by crimping the flange  48 , then the nozzle/hinge assembly is snapped onto the mounting cup of the valve. 
     The stroke of the valve is limited by the clearance X between the lower end of the extension  110  and the top of the mounting cup  44  adjacent to the inner flange  46 . The length of the extension  110  is therefore carefully chosen depending on the flow characteristics of the product to be dispensed. Before filling the can  12  with product and before fitting the valve and nozzle/hinge assembly, a piston assembly (not shown) is inserted into the can  12 . A suitable piston assembly is described in our co-pending International Patent Application No PCT/GB98/03003. However the piston assembly does not form part of the present invention, and any suitable automatic or manual pressure inducing arrangement may be used in connection with the apparatus of the present invention, including conventional aerosol cans. 
     To dispense a product, the tab  86  is broken, the end cap  82  is removed and the nozzle  80  may be cut open, if it is not supplied already open. The nozzle assembly  20  is then twisted relative to the hinge assembly  16 . Twisting is made easy by the provision of the four fins  92 ,  94 , which are readily grasped by hand. A 90° turn will fully open the pack. As the nozzle assembly  20  turns, the lever handle  102  lifts on the hinge  72  due to the action of the camming surface  96 ,  98  against the bearing portion  100  of the lever arm  104 . This can be seen in the view of FIG.  2 ( a ) and  2 ( b ). 
     To dispense product, a user then presses down on the lever handle  102  (moving it toward the body of the can  12 ). This pushes the nozzle assembly  20  and valve stem  30  down relative to the hinge assembly  16 , as described above. This is the position seen in FIGS.  3 ( a ) and  3 ( b ). Product is then urged to flow, by virtue of the internal pressurisation of the pack through the ports  32  and up through the valve stem  30  and out through the nozzle  80 . 
     To stop dispensing, the user simply releases the lever handle  102 . This closes the valve by allowing the valve stem  30  to slide back and close access through the ports  32 . 
     Although FIGS. 1 to  7  show a simple camming surface in which there are two positions, a closed position in which the valve is fully closed and the dog cannot locate in the slot, and an open position in which the valve is fully open and the dog can locate in the slot, it is in the scope of the present invention to provide a more sophisticated camming surface, which may provide intermediate raised surfaces, whose height is between that of the depression  98  and highest raised surface  96 . Further slots may be provided in flange  66  corresponding with the intermediate camming surfaces, so that the valve may be actuated in one or more intermediate, partially open positions. Alternatively the dogs  112  and flange  66  may be omitted, thereby simplifying the operation of the apparatus so that the valve can be actuated in any rotational position of the nozzle, the degree of rotation determining the extent to which the valve will open when actuated. Detent grooves may be provided in the camming surface, adapted to cooperate with the bearing portion  100  of the lever, to give a positive click action when the nozzle is rotated to an open position. 
     FIG. 8 shows an alternative form of hinge assembly  116 , made of steel, alloy or other metal. The assembly comprises a ring  130  which fits around the rolled flange  13  of the container  12  before the mounting cup  44  of the valve  14  is fixed to the flange  13 . Fixing the mounting cup holds the ring  130  in place. The upstand  132  and hinge  134  are formed by bending the single flat sheet of metal from which the hinge assembly  116  is formed. The bearing surfaces  136   a ,  136   b  at the end of the upstand  132  serve the same purpose as the bearing surfaces  74   a ,  74   b  described above with reference to FIGS.  7 ( d ) and  7 ( e ). 
     Modifications and improvements may be made to the foregoing without departing from the scope of the invention. In particular the dog mechanism may be omitted if there is another means of ensuring that the nozzle is not accidentally depressed, for example the provision of an outer cap which fits over the whole assembly on to the top of the canister. Similarly the fins may be omitted, and the lever may be retained in some other way, or may be free to rise away from the cam surface.

Technology Category: 7