GB2360733A

GB2360733A - Container sealing method and apparatus

Info

Publication number: GB2360733A
Application number: GB0005044A
Authority: GB
Inventors: Jack Lee Holt; Peter Graham Crookes
Original assignee: STELRAM ENGINEERING Ltd
Current assignee: STELRAM ENGINEERING Ltd
Priority date: 2000-03-03
Filing date: 2000-03-03
Publication date: 2001-10-03
Also published as: GB0005044D0

Abstract

A method and apparatus for sealing covers 28 to containers 21 comprises supporting the container on a first sealing member 30 mounted on a first support (16 figure 6) and supporting a cover on the container and moving the support relative to a second sealing member 18 mounted on a second support (12 figure 1) whereby at least one sealing member pivots relative to its support. The support may pivot in two axes which may be perpendicular to each other. The pivots may be formed by gimbals 32 and 34 being pivoted on projections 36 located on the second gimbal 34 which locate with recesses on the first gimbal 32 which may form a frame with an aperture for the container. Projections 40 on second gimbal 34 allow the support to pivot in a second perpendicular plane. The sealing means may use a heat activated adhesive. The first and second supports may be pivoted (15 figure 1) together and may have magnetic locking means (50 figure 6). Means may be provided to remove the container after sealing. The container which may be for take away food may be supported in the apparatus by a flange 26 on the container.

Description

2360733 CONTAINER SEALING APPARATUS

Field of the Invention

The invention relates to container sealing apparatus and especially, but not limited to, food carton sealing apparatus.

Background to the Invention

Conventional food cartons comprise a foil carton having a cardboard lid. The food is contained in the carton by bending a section of the foil carton over to prevent the cardboard lid working loose. However, the seal does not prevent fluid flow and, therefore, if the carton is not horizontal liquid may flow out of the carton. In addition, air may enter the carton and may cause the food to deteriorate faster compared to a carton which is maintained in an air tight atmosphere. Contaminants may also be able to enter the carton.

Plastic cartons are available which are sealed by heating a plastic film on to the periphery of the carton. A machine for sealing such cartons exterts a pressure between the film and the periphery of the carton. It is important that an equal pressure is applied around the full periphery in order for a seal to be produced. If the pressure is uneven then a section of the film may not be secured to the carton and liquid may be able to flow from the carton. Accordingly, it is important that the pressure plates of the sealing machine are manufactured to a high tolerance in order for the plates to exert an even force. Alternatively, a very high pressure force can be 2 applied in order to try and ensure that a force is applied around the entire periphery of the carton. This, therefore requires heavy or high pressure means which can be expensive, inefficient and difficult to use. The presence of high forces also increases the accident risks.

Furthermore, plastics cartons and lids have disadvantages in that they are expensive and are non biodegradable.

It is an aim of the present invention to overcome at least 10 one problem with the prior art whether referred to herein or otherwise.

Summary of the Invention

According to a first aspect of the present invention there is provided container sealing apparatus comprising a first sealing member mounted on a first support and a second sealing member mounted on a second support, wherein said first and second supports are movable relative to each other, and wherein the first sealing member is pivotally mounted on the first support in order to pivot about at least one axis relative to first support.

Preferably the first sealing member is pivotally mounted on the first support in order to pivot about a first axis and a second axis relative to the firstsupport.

Preferably the first axis and second axis are at an angle to each other and preferably the first axis and second axis are substantially perpendicular. Preferably the first axis is the longitudinal axis of the first sealing member and preferably the second axis is the lateral axis of the first sealing member.

3 Preferably the first sealing member is mounted on the first support by a support element. The support element may project through at least one washer and preferably projects through two washers. Preferably the or each washer is located between the first sealing member and the f irst support. The first washer may be a male washer which may have a convex surface and preferably has a spherical convex surface. The second washer may be a female washer which may have a concave surface and preferably has a spherical concave surface. Preferably the surface of the first washer substantially corresponds to the surface of the second washer.

Preferably the first sealing member comprises a first gimbal. Preferably the first sealing member may further comprise a second gimbal on which the first gimbal may be pivotally mounted. Preferably the second gimbal is pivotally mounted on the first support.

Preferably the first sealing member includes a planar surface, which planar surface is preferably provided by a part of the first gimbal.

Preferably the first gimbal is a continuous frame member having an aperture defined therein. Preferably the second gimbal is a continuous frame member having an aperture defined therein. The first gimbal may have a seal mounted on it, which seal may comprise a resilient seal. The seal may comprise a continuous resilient seal. Preferably the seal is a silicone seal.

Preferably the second sealing member comprisesa planar surface which may be substantially rectangular.

4 Preferably the second sealing member comprises heating means. The second sealing member may comprise an electrical heating element located therein. The second sealing member may comprise projections. The second sealing member may be mounted on the second support such that heat is restricted from being transmitted from the second sealing member to the second support.

Preferably the second sealing member is not movable relative to the second support.

Preferably the first support is pivotally connected to the second support. Preferably the first support can pivot between at least a first and second position relative to the second support. Preferably in the first position access to the first sealing member is possible. In the second position the first sealing member may co-operate with the second sealing member. In the first position a container and a cover may be placed and supported on the first sealing member. In the second position a container and a cover may be urged together. The apparatus may comprise locking means to lock the first support to the second support in the second position. The locking means may comprise a magnet to lock the first support to the second support. The magnet may be an electromagnet. Preferably, control means are provided to switch the electromagnet on and off. The control means may comprise timing means which automatically switches the electromagnet off after a predetermined time.

Preferably the container sealing apparatus is arranged, in use. to seal a cover to a container.

The container sealing apparatus may comprise timing means. The timing means they may record the time that the first and second support are in the second position.

The container sealing apparatus may comprise means for moving the first and second support relative to each other.

The container sealing apparatus may comprise means to aid the removal of a container from the apparatus. The means may be arranged, in use, to at least partially raise a container with respect to the container sealing apparatus. The means may comprise a lifting member which is arranged, in use, to abut a part of the bottom of a container. The means may be manual means. The means may comprise a lever which is pivotally mounted on the apparatus and is arranged, in use, to operate the lifting member.

According to a second aspect of the present invention there is provided an assembly comprising container sealing apparatus in accordance with the first aspect of the present invention and a container and a cover.

The container may be a carton and preferably is a carton for containing food. The carton may be a take-away food carton.

Preferably the container comprises an outer flange. The outer flange of the container may be arranged, in use, to be supported by the first sealing member. At least a part of the cover may be supported, in use, by the outer f lange of the container.

6 The container and/or the cover may comprise a heat actuated adhesive. The container and/or the cover may comprise a cardboard material. Preferably the container and/or the cover comprise a cardboard material impregnated 5 with a heat actuated adhesive.

Preferably the container and/or the cover comprise a microwavable material. Preferably the container and/or the cover comprise a biodegradable material.

The first and second supports may be movable between at least a first and second position. Preferably in the first position the container and the cover can be placed in the container sealing apparatus. Preferably in the second position at least a part of the cover and the outer flange of the container are urged together. Preferably in the second position at least a part of the cover and at least a part of the container are heated. In the second position at least a part of the cover and at least a part of the container may be heated by heating means which are preferably located in the second sealing member.

According to a third aspect of the present invention there is provided a method of sealing a container comprising supporting the container on a first sealing member mounted on a first support and supporting a cover on at least a part of the container, and moving the first sealing member mounted on the first support relative to a second sealing member mounted on a second support whereby at least one of the sealing members pivots relative to its respective support.

7 Preferably the first sealing member pivots relative to the first support due to a torque produced by the second sealing member.

Preferably at least one of the sealing members pivots about two axes relative to its respective support.

Preferably the method comprises heating one of the sealing members. Preferably the method comprises heating at least a part of the cover and/or at least a part of the container.

A Brief Description of the Drawings

The present invention will now be described, by way of example only, with reference to the drawings that follow, in which:

Figure 1 is a perspective view of container sealing apparatus.

Figure 2 is an exploded perspective view of a carton and cover.

Figure 3 is a cross section through a part of the container sealing apparatus.

Figure 4 is a perspective view of the arrangement of the gimbals.

Figure 5 is a front perspective view of a further embodiment of container sealing apparatus.

8 Figure 6 is a front perspective view of a further embodiment of container sealing apparatus with the lid in an open position.

Figure 7 is a rear perspective view of a further embodiment of a further embodiment of container sealing apparatus.

Figure 8 is a rear perspective view of a further embodiment of container sealing apparatus with the lid in an open position.

Figure 9 is a lateral cross-section view of a further embodiment of container sealing apparatus.

Figure 10 is a longitudinal cross-section view of a further embodiment of container sealing apparatus.

Figure 11 is a lateral cross-section view of a further embodiment of container sealing apparatus having container removal means.

Description of the Preferred Embodiment

As shown in figure 1, container sealing apparatus 10 has a first support in the form of a lid 12 and a second support in the form of a base 14. The lid 12 is connected to the base 14 by two pivots 15. The lid 12 can be opened and closed relative to the base 14. In the open position a container, for example a take away food carton, can be placed into the base 14. The container or carton 21 has an outer flange 26 and a body 22, as shown in figure 2. The carton 21 is placed in the package sealing apparatus 9 such that the outer flange 26 is supported by a first sealing member comprising a support 16 in the base 14 of the package sealing apparatus 10. The support 16 has an aperture defined therein. The body 22 of the carton 21 5 thereby locates in the recess 20 surrounded by the support 16 in the base 14.

The cover 28 or lid is placed on top of the carton 21. The cover 28 covers the carton 21 and is supported by the outer flange 26 of the carton 21. The carton 21 and the cover 28 are made of a cardboard material. The cardboard material is impregnated with a heat actuated adhesive whereby when heat is applied to the cardboard material the adhesive is actuated. 15 The cover 28 and the carton 21 are located in the base 14 whilst the lid 12 is in the open position. The lid 12 is then pivoted about the pivots 15 and is manually moved towards the closed position. The lid 12 has a handle 19 to enable the lid 12 to be easily moved.

The lid 12 supports a second sealing member in the form of a heating element 18 on the inner face of the lid 12. The heating element 18 is a block of heat conductive material with an electrical heating element located therein. In use, the heating element 18 provides a planar heated surface. As the lid 12 is closed the planar heated surface of the heating element 18 abuts the top surface of the cover 28. The planar heated surface is pressed on to the cover 28 and urges the cover 28 and the outer flange 26 of the carton 21 together. The cover 28 and the outer flange 26 of the carton 21 are heated by the conduction of heat from the heating element 18 which causes the impregnated adhesive to actuate. After a predetermined period of time the cover 28 will be sealed to the flange 26 of the carton 21.

To avoid the problems of the prior art a continuous seal is ensured by the present invention by mounting the support 16 on two gimbals 32, 34 as shown in figures 3 and 4. The two gimbals 32, 34 are secured on pivots. The arrangement enables the flange 26 and cover 28 to pivot with respect to the planar heated surface about two perpendicular axes.

The support 16 comprises a resilient seal member 30 which may be a silicone rubber seal. The seal member 30 is mounted on the first gimbal 32. The first gimbal 32 is a continuous frame member comprising a rigid material, for example a metal. The f irst gimbal 32 is supported on the second gimbal 34 by two cylindrical projections 36 which are located in recesses in the outer face of the first gimbal 32. The cylindrical projections 36 are received in co-operating apertures located on projections 38 provided on the upper face of the second gimbal 34. The arrangement enables the first gimbal 32 to pivot with respect to the second gimbal 34. There are two pivot arrangements located on both longitudinal sides of the gimbal arrangement. The two pivot arrangements are located midway along the longitudinal length of the first gimbal 32. This ensures that the first gimbal can pivot to the same degree in both the clockwise and anticlockwise directions.

The second gimbal 34 has two cylindrical projections 40 on the outer face. The two cylindrical projectionsare located midway along the lateral length of the second gimbal 34. The cylindrical projections 38 are received in j - 1 - co-operating apertures located on an inner face in the base 14. This enables the second gimbal 34 to pivot with respect to the base 14. Overall, the seal member 30 is able to pivot in both the clockwise and anticlockwise directions about both a longitudinal axis and a lateral axis with respect to the base.

As the lid 12 is closed the planar heated surface abuts the cover 28. As pressure is applied the seal member 30 will pivot until it resides in the same plane as the planar heated surface. This occurs due to the planar heated surface applying a torque on the seal member 30 until the seal member is in a parallel plane relative to the planar heated surface. Accordingly, the outer flange 26 of the carton 21 and the cover 28 will also realign. Therefore, as pressure is applied the pressure will be distributed evenly over the outer flange 26 of the carton 21.

After a predetermined period of time the body of the carton 22 will be sealed to the cover 28 and the lid 12 is opened. The carton 21 can then be removed f rom the base 14.

The seal member 30 w hich comprises a resilient material also encourages an even distribution of pressure about the flange of the carton. The container sealing apparatus may include a timer which automatically times the length which the lid should be in the closed position.

The container sealing apparatus 10 may have locking means which lock the lid 12 and the base 14 in the closed, position whilst the cover 28 is being sealed to the carton 21. The lock may be an electromagnet which is controlled by control means. The timer may be connected to the control means such that the lid 12 is locked to the base 14 in the closed position for a predetermined time, which is sufficient for the cover 28 to adhere to the carton 21.

The container sealing apparatus 10 may also provide means for easily removing the sealed container from the container sealing apparatus.

Alternatively the gimbal arrangement could be arranged to mount the heating element 18 to the lid 12. This will provide the same result since the sealing member 30 and the heating element 18 will still pivot relative to each other.

A further embodiment of container sealing apparatus 10 also comprises a lid 12 and a base 14, as shown in figures to 10. The container sealing apparatus 10 also comprises a handle 19 to enable the lid to be easily moved between an open position and a closed position.

The container sealing apparatus 10 has locking means to lock the lid 12 to the base 14 in a closed position. The locking means comprises an electromagnet 50 which cooperates with a locking element 52 in the closed position. Accordingly, control means can be used to lock the container sealing apparatus 10 in a closed position for a predetermined period of time.

13 The container sealing apparatus 10 has a support 16 which has an aperture defined therein in order to provide a recess 20. The support 16 is arranged, in use, to support the outer flange 26 of the carton 21.

The lid 12 supports a sealing member in the form of a heating element 54. The heating element 54 is a planar element which has projections defined thereon which substantially correspond to the size and shape of the outer flange 26 of the carton 21. The heating element 54, thereby, only heats the part of the cover 28 which is to be adhered to the carton 21. Again, the operat ion of the container sealing apparatus 10 is the same as previously described in that the carton 21 and cover 28 are placed in the recess 20 and are supported by the support 16. The lid 12 is then closed and locked in the closed position by the locking means for a predetermined period of time. Whilst locked, the heating element 54 heats a part of the cover 28 which releases a heat actuated adhesive which thereby adheres the cover to the carton 21. Once the control means releases the locking means, the lid 12 can be moved into an open position either manually or using automatic means in order for the carton to be removed.

However, the further embodiment of container sealing apparatus 10 does not have a gimbal arrangement in order to ensure a continuous seal but uses a spherical washer arrangement in order for the heating element to align to be in the same plane as the support 16 and the outer flange 26 and the cover 28.

As shown in figures 9 and 10, the heating element 54 comprises a heating plate 56 which is planar and has 14 projections 58 which project downwardly. There is a heater 60 which is located directly above the heating plate 56. Above the heater 60 is a layer of insulating material 62. Finally, there is a clamp plate 64 located directly above the layer of insulating material 62. The heating element 54 is connected to the lid 12 by a support element in the form of a screw 66 which is secured at one end to the clamp plate 64. The shaft of the screw 66 projects through an aperture provided in the lid 12 and is retained therethrough. A first washer 68 and a second washer 70 are located along the shaft of the screw 66 between the upper f ace of the clamp plate 64 and the lower face 72 provided by the lid 12. The first washer 68 is a male washer and comprises a convex spherical face which is arranged to correspond with a concave spherical face provided by the second washer 70 which is female.The arrangement of the washers 68, 70 results in the heating element 54 being able to move about a longitudinal axis and a lateral axis with respect to the lid 12. This, thereby, provides the same function as the early described gimbal arrangement in that as pressure is applied to the lid 12 as it is closed the heating element 54 will pivot until it resides in the same plane as the support 16.

Again, the support 16 may be supported by the spherical washer arrangement rather than the heating element in order to provide the same function.

As shown in Figure 11, the container sealing apparatus may have means for helping to lift a carton out of the container sealing apparatus. The means comprises a lifting member 76 which is shaped in order to cooperate with the underside of a carton. The lifting member is connected to a lever 78 which is mounted the container sealing apparatus 10 by a pivot 80. The lever 78 can be manually pivoted downwardly such that the lifting member pivots upwardly until it abuts the underside of a carton located in the container sealing apparatus. Further movement of the lever thereby causes the carton to move upwardly in order for the carton to be easily removed from the apparatus.

A resilient seal 74 may be located around the periphery of the heating plate 56. The resilient seal 74 may be a "D" shaped silicone rubber seal. The resilient seal 74 prevents axial rotation of the heating element 54 around the spherical washers. In addition the resilient seal 74 prevents the ingress of foreign bodies into the apparatus, for example water or food. Finally, the heating element 54 is spaced from the lid 12 in order for heat to be prevented from conducting from the heating element 54 to the lid 12.

The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

16 Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extend to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

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Claims

1. Container sealing apparatus comprising a first sealing member mounted on a first support and a second sealing member mounted on a second support, wherein said first and second supports are movable relative to each other, and wherein the first sealing member is pivotally mounted on the first support in order to pivot about at least one axis relative to first support.

2. Apparatus according to claim 1 in which the first sealing member is pivotally mounted on the first support in order to pivot about a first axis and a second axis relative to the first support.

3. Apparatus according to claim 2 in which the first axis and second axis are at an angle to each other.

4. Apparatus according to claim 3 in which the first 20 axis and second axis are substantially perpendicular.

5. Apparatus according to any preceding claim in which the first axis is the longitudinal axis of the first sealing member.

6. Apparatus according to any one of claim 2 to claim 5 in which the second axis is the lateral axis of the f irst sealing member.

7. Apparatus according to any preceding claim in which the first sealing member comprises a first gimbal.

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8. Apparatus according to claim 7 in which the first sealing member may further comprise a second gimbal on which the first gimbal may be pivotally mounted.

9. Apparatus according to claim 7 or claim 8 in which the first sealing member includes a planar surface which planar surface is provided by a part of the first gimbal.

10. Apparatus according to any one of claim 7 to claim 9 in which the first gimbal is a continuous frame member having an aperture defined therein.

11. Apparatus according to claim 8 or claim 9 or claim 10 when dependent on claim 8 in which the second gimbal is a continuous frame member having an aperture defined therein.

12. Apparatus according to any one of claim 7 to claim 11 in which the first gimbal has a seal mounted on it.

13. Apparatus according to claim 12 in which the seal comprises a resilient seal.

14. Apparatus according to any preceding claim in which the second sealing member comprises a planar surface.

15. Apparatus according to any preceding claim in which the second sealing member comprises heating means.

16. Apparatus according to any preceding claim in which the second sealing member is not movable relative to the second support.

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17. Apparatus according to any preceding claim in which the first support is pivotally connected to the second support.

18. Apparatus according to claim 17 in which the first support can pivot between at least a first and second position relative to the second support.

19. Apparatus according to claim 18 in which in the first position access to the first sealing member is possible.

20. Apparatus according to claim 18 or claim 19 in which in the second position the first sealing member cooperates with the second sealing member.

21. Apparatus according to any one of claim 18 to claim 20 in which on the first position a container and a cover can be placed and supported on the first sealing member.

22. Apparatus according to any one of claim 18 to claim 21 in which in the second position a container and a cover can be urged together.

23. Apparatus according to any one of claim 18 to claim 22 in which the apparatus comprises locking means to lock the first support to the second support in the second position.

24. Apparatus according to any preceding claim in which the container sealing apparatus is arranged, in use, to seal a cover to a container.

25. Apparatus according to any preceding claim in which the apparatus comprises means to aid the removal of a container from the apparatus.

26. Apparatus according to claim 25 in which the means is arranged, in use, to at least partially raise a container with respect to the container sealing apparatus.

27. Container sealing apparatus substantially as herein described with reference to, and as shown in any of the accompanying drawings.

28. An assembly comprising container sealing apparatus in accordance with any one of claim 1 to claim 27 and a container and a cover.

29. An assembly according to claim 28 in which the container may be a carton.

30. An assembly according to claim 29 in which the carton is a carton for containing food.

31. An assembly according to any one of claim 28 to claim 30 in which the container comprises an outer flange.

32. An assembly according to claim 31 in which the outer flange of the container is arranged, in use, to be supported by the first sealing member.

33. An assembly according to claim 31 or claim 32 in which at least a part of the cover is supported, in use, by the outer flange of the container.

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34. An assembly according to any one of claim 28 to claim 33 in which the container comprises a heat actuated adhesive.

35. An assembly according to any one of claim 28 to claim 34 in which the cover comprises a heat actuated adhesive.

36. An assembly substantially as herein described with reference to, and as shown in any of the accompanying drawings.

37. A method of sealing a container comprising supporting the container on a first sealing member mounted on a first support and supporting a cover on at least a part of the container, and moving the first sealing member mounted on the first support relative to a second sealing member mounted on a second support whereby at least one of the sealing members pivots relative to its respective support.

38. A method according to claim 37 in which the f irst sealing member pivots relative to the first support due to a torque produced by the second sealing member.

39. A method according to any one of claim 37 to claim 38 in which at least one of the sealing members pivots about two axes relative to its respective support.

40. A method according to any one of claim 37 to claim 39 in which the method comprises heating one of the sealing members.

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41. A method of sealing a container substantially as herein described, and as shown in any of the accompanying drawings.