GB2470916A

GB2470916A - Foiled closure with swivel member

Info

Publication number: GB2470916A
Application number: GB0909892A
Authority: GB
Inventors: Peter Michael Mcgeough; Andrew Bell; Fergus Shepherd
Original assignee: Bapco Closures Research Ltd
Current assignee: Bapco Closures Research Ltd
Priority date: 2009-06-09
Filing date: 2009-06-09
Publication date: 2010-12-15
Also published as: GB0909892D0

Abstract

A closure has a spout 2 which is adapted to be fitted to a neck of a container (not shown). An overcap 4 closes the spout and a swivel part 6 is held in place within a depending valve 8 in the overcap. The swivel 6 and the spout 2 are both welded to one face of an induction heat sealing foil disc 12. The engagement between the swivel 6 and the valve 8 of the overcap 4 takes the form of an inclined rim 30 on the swivel 6 that engages with a bead 40 on the valve 8 so as to lift/ cam the swivel 6 on rotation of the overcap 4 so as to initiate a tear in the foil disc 12. The depending valve 8 may have vents 54 to permit water vapour to escape from an interior of the overap 4. The spout may also have teeth 18 adapted to pierce the foil disc 12, and ease tearing. To open the closure the user twists the overcap causing the valve to rotate relative to the swivel part. The overcap then lifts the swivel part by means of the camming engagement between the bead 40 in the recess 34, enabling the tear to be easily propagated around the remainder of the disc as the foil is stretched over the teeth 18.

Description

Closure

Technical Field

[0001] The present invention relates to a pre-foiled BAP� closures of the type invented by Bapco Closures Research Ltd (formerly known as Spreckelsen McGeough Ltd) and described, for example in WO 99/61337 A (SPRECKELSEN MCGEOUGH LIMITED) 02/1 2/1 999 and, more particularly GB 2350105 A (SPRECKELSEN MCGEOUGH LTD) 22/11/2000 the disclosure of which is incorporated herein by reference.

Background Art

[0002] BAP� pre-foiled closures comprise a spout closed by a double sided plastics-coated induction heat sealing foil, a removable part in the spout which is also welded to the foil and an overcap. Such a closure can be assembled to a wide variety of containers including bottles, cartons and cans by creating a secondary weld between the exposed face of the foil and an element of the container.

Technical Problems [0003] Problems associated with the design shown in GB 2350105 A (SPRECKELSEN MCGEOUGH LTD) 22/11/2000 are that it is difficult to open because the bond between the swivel plate and the foil needs to be severed all the way round the plate at one time. The opening force is therefore considerable especially for larger diameter openings such as 39mm closures.

[0004] When containers closed with BAP� pre-foiled closures are used in food processing techniques such as retort or hot-filling, a problem can arise with excess water condensing inside the closure.

[0005] Standard BAP� pre-foiled closures have a removable part such as a ring pull that has to be removed in a separate action. Consumers prefer one action opening and no litter element to dispose of.

[0006] The closure of the present invention seeks to solve these problems.

Brief Description of Figures in the Drawings

[0007] In order that the invention may be well understood, an embodiment thereof will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: [0008] Figure 1 is a section through an assembled pre-foiled closure in accordance with the invention; [0009] Figure 2 is a section through an overcap; [0010] Figure 3 is a section on line B-B in Figure 2; [0011] Figure 4 is a section through a spout; [0012] Figure 5 is a view of the spout from below in the direction of arrow A in Figure 4; and [0013] Figure 6 is a section through a removable opening device.

Mode(s) for Carrying Out the Invention [0014] The illustrated combination closure has a spout 2 which is adapted to be fitted to a neck of a container (not shown). An overcap 4 closes the spout and a removable swivel part 6 is held in place inside the overcap by means of a depending valve 8. The swivel part 6 and the spout 2 are both welded to one face of an induction heat sealing foil disc 12.

[0015] The spout 2 defines an opening 14 surrounded by a base flange 16. The underside of the base flange 16 has teeth 18 moulded into it in order to facilitate tearing of the foil discl2 which is induction heat sealed to the base flange 16 and closes the opening 14 in the spout. A wall 20 extends from the base flange and has an external rib formation 22. This wall 20 forms a spout neck.

[0016] The swivel part 6 is mounted within the spout 2 and is attached to the overcap so that it can swivel relative to the overcap during an opening operation. This swivel part 6 is a hollow cylinder with an annular base 24 that is adapted to be welded to the foil disc 12 and a side wall 26 which increases in height from one side of the part to the other. A top face 28 of the swivel part is inclined at an angle to the base 24. An external rim 30 is formed around an upper edge of the top face. An external rim 32 is also formed around the base 24. Together these rims define a recess 34 in the external face of the side wall of the swivel part. The recess 34 is sized at the lowest part of the side wall to receive a bead 40 that projects from the valve 8 in the overcap 4. Buttresses 36, of which four are proposed in the illustrated embodiment are provided inside the side wall 26 in order to maintain its rigidity. The under surface 38 of the rim 30 provides a surface which interacts with the bead 40 to lift the swivel part 6 during an opening operation.

[0017] The overcap 4 is shown in Figure 2 and 3. The overcap has a skirt 42 with a rib 44 designed to co-operate with rib 22 to enable the overcap to engage with the spout. The depending valve 8 within the overcap terminates in the inwardly facing annular bead 40 that engages with the recess 34 in the wall 26 of the removable swivel part 6. As illustrated the interior of the overcap valve is open. Chevron shaped vents 54 are provided around the valve 8. Four are shown in the embodiment. Six vents could also be used. These vents 54 allow the drying of excess water which accumulates during a retort or hot fill cooling process in the interior of the cap.

[0018] At one side of the valve 8 a cap shaped projection 50 extends externally of the valve 8 towards an internal face of the skirt 42. The projection could extend around the whole of the valve but this would make it difficult to manufacture by a moulding process. The projection 50 provides support for the valve as torque is applied during an opening process. It ensures that the bead 40 is tightly engaged with the recess at least at a particular rotational position of the overcap in order to resist rotation. This creates a point at which rotation force applied to the overcap by a consumer will be transmitted in a concentrated manner to the foil in the arc below the projection and create a sufficient stress in that confined section of foil to initiate a tear.

[0019] A top face of the overcap within the valve may be closed by means of an insert or plug 52 after any water has been vented.

[0020] The induction heat sealing foil disc 12 has an aluminium core layer that has plastics layers adhered to each face as used in existing BAP� closures. The material of the plastics layers is chosen so that it is compatible on one face with the material from which the swivel and spout are moulded and on the other face with the material of a container to which the closure is to be applied.

[0021] All three components, spout 2, swivel 6 and overcap 4 are preferably injection moulded plastics components. Suitable plastics materials are selected in order to provide a structure of the required rigidity.

Assembly [0022] The closure is assembled by fitting the swivel 6 to the overcap 4 and engaging the bead 40 in the recess 34. The spout is then engaged with the overcap and swivel assembly. The foil disc 12 is then placed into the base of the inverted closure and held in place by a mandrel while the assembly is passed into an induction field designed to create a primary weld between the disc and the base flange and the base 24. Two concentric annular welds either side of the region in which the teeth 18 are formed are created.

[0023] The pre-foiled closure can then be induction heat sealed to a container in a separate step to create a secondary weld between the container and the base flange externally of the primary weld.

Opening of the Closure [0024] To open the closure the user twists the overcap. This causes the valve 8 to rotate relative to the swivel part. Where the projection 50 engages with the wall of the spout there is a resistance to this rotation and with continued application of force a tear will be initiated in this region. Further rotation of the overcap will then lift the swivel part by means of the carnming engagement between the bead 40 in the recess 34 enabling the tear to be easily propagated around the remainder of the disc as the foil is stretched over the teeth 18.

[0025] The closure is therefore opened in a single operation. The swivel and foil disc are retained within the overcap. This eliminates the litter problem. The overcap can be used to reseal the opening 14 as the rim 32 will seal against the base flange 16. The foil 12 will remain intact across the base of the swivel to complete the seal. An insert plug can also be provided to fit into the top of the valve.

[0026] The projection 50 on the outside of valve prevents deflection of overcap valve 8 and subsequent separation from the weld swivel during the removal operation.

[0027] The components are designed to keep the structures supported during the removal process.

Claims

Claims 1. A closure comprising a spout having a base flange surrounding an opening and an upstanding wall (20), an overcap adapted to engage with an outer side of the spout wall and having a depending valve (8) that extends into the spout, a swivel (6) supported within the opening by means of engagement with the depending valve, an induction heat sealed foil welded across the opening and bonded to the swivel part and the base flange, characterised in that the engagement means between the swivel (6) and the valve comprises an inclined rim (30) on the swivel that engages with a bead (40) on the valve so as to lift the swivel on rotation of the overcap to initiate a tear in the foil.
2. A closure as claimed in claim 1, characterised in that the swivel is a hollow cylinder with an annular base (24) that is welded to the foil.
3. A closure as claimed in claim 2, characterised in that the depending valve has vents (54) to permit water vapour to escape from an interior of the overcap.
4. A closure as claimed in any one of the preceding claims, characterised in that a projection (50) projects from the valve towards an internal face of a skirt of the overcap.
5. A closure substantially as herein described with reference to the accompanying drawings.