CLOSING DEVICE FOR A HOLDER AND MEMBRANE FOR SUCH A CLOSING DEVICE

Abstract: A deformable holder is safeguarded against visible implosion by a diaphragm between cover and holder. The space (15) between diaphragm and cover is in contact with the atmosphere via passages (14) between diaphragm and cover, while the holder is hermetically closed off from the outer air by the diaphragm.

Description: The invention relates to a closing device according to the preamble of claim 1. Such a closing device is known from CH-A-443951 or FR-A-2104439. This prevents a thin-walled container deforming in an unacceptably visible manner should an underpressure occur in the container, since the space present between the cover and the diaphragm is in contact with the atmosphere via a small opening arranged in the centre of the cover. In case the diaphragm is removed from the cover during the time that the cover is disconnected from the container, the container space will later on communicate with the exterior through the central hole. Such situation is not acceptable for food. The invention has for its aim to provide a container of thin-walled and easily deformable material which can be opened repeatedly and hermetically closed off from the ambient atmosphere, whereby implosion in the case of a possibly occuring underpressure is prevented without a central opening in the cover. To this end, the feature of claim 1 is applied. The invention likewise relates to a diaphragm for such a closing device as described in claim 7. It is marked that FR-A-2070788 discloses a closing device for a container whereby a paste is released by squeezing in the container. In order to ensure that the container assumes its original shape after being squeezed, communication with the ambient atmosphere is effected between a cover and a diaphragm via grooves arranged in the diaphragm and via an opening arranged in the diaphragm. During storage the contents of the container are in contact with the ambient atmosphere, which is precisely the opposite of the object of the present invention. The invention will be elucidated in the description following hereinafter with reference to drawings. In the drawings: fig. 1 shows a longitudinal section through a container having a preferred embodiment of a closing device according to the invention; fig. 2 shows on a larger scale a fraction II from fig. 1; fig. 3, 5, 6 and 7 each show a longitudinal section in each case through a different container with a different closing device according to the invention; and fig. 4 shows a longitudinal section similar to fig. 3 in another closing position. A container 4, for example a jar or a bottle, particularly for food products, medicine and the like, has a neck 3 with screw thread 5, the neck bounding an opening 6. Opening 6 is closed by means of a closing device 7 according to the invention, comprising a cover 2 which grips on screw thread 5 with internal thread 8 and which is arranged over opening 6. Instead of a continuous screw thread connection a discontinuous screw thread closure may be applied. Arranged between opening 6 and cover 2 is a diaphragm 1 of closure 7. The diaphragm 1 has a form essentially deviating from a flat shape, since the diaphragm lies with its flange 10 on the upper edge 11 of container opening 6, and from there extends downward at a sloping angle a and inward into a bend 12. The central part 13 located inside bend 12 is dome-shaped. The diaphragm 1 is for example manufactured from polyethylene which is soft and can easily be deformed elastically. Present on the top of flange 10 are a number of grooves 14 distributed over the periphery and arranged between ribs in order to place the space 15 between cover 2 and diaphragm 1 in contact with the atmosphere. The flange 10 of diaphragm 1 is on the other hand pressed so tightly onto edge 11 of the neck by means of cover 2, that diaphragm 1 closes off container 4 hermetically. In the case a vacuum should arise in the container, for example because of cooling of the food product contents of container 4 and/or condensation of vapour present in container 4, the diaphragm 1 will move downward while it deforms and air escapes into space 15 via grooves 14. When container 4 is opened for use, cover 2 is unscrewed and diaphragm 1 is removed and thrown away. A lip 18 is present for gripping the diaphragm. After removal of part of the contents, container 4 can be closed hermetically with cover 2 whereby an internal, deformable lip 16 of cover 2 makes a sealing connection to top edge 11. The thin-walled container 4 can consist for example of polyester with a wall thickness of 0.4-0.6 mm with a content of several litres, decilitres or centilitres. If the diaphragm is very elastic, it may possibly be flat in the starting position. It is also conceivable that diaphragm 1 from fig. 1 is manufactured of a thin plastic deformable material such as deep drawn polystyrene with a wall-thickness of 0.1-0.2 mm, or of deep drawn thin aluminium. Diaphragm 1 from fig. 1 has a lip 18 with which it can easily be pulled off opening 6. Diaphragm 1 preferably consists of polyethylene. Cover 2 preferably consists of polypropylene. Closing device 7 is preferably pre-assembled as a whole, whereby flange 10 is accommodated for locking at the lip 16 of cover 2, so that the closing device 7 can be supplied integrally to a closing machine and a container 4 can be closed by the closing machine in one operation. The closing device 37 from fig. 3 comprises a cover 32 with a diaphragm 31 which lies with its flange 57 for sealing against the top edge 11 of container 34 which is identical to container 4 from fig. 1. This thin diaphragm 31 again has a non-flat, easily deformable shape. A space 45 between diaphragm 31 and cover 32 is in contact with the atmosphere via grooves 60 between ridges 58 lying on edge 57. The lip 46 of cover 32 closes off container 34 hermetically when, as according to fig. 4, diaphragm 31 is removed by gripping on a lip 18. When as according to fig. 3 the diaphragm 31 is in fact present, the lip 46 rests on ribs 59 so that air can pass between ribs 59 and lip 46. The closing pressure is realized in fig. 3 and 4 through internal screw thread 8 on cover 32 and internal screw thread or screw thread pieces 5 on the container neck 3. Each closing device 67 of fig. 5, 6 and 7 corresponds to that of fig. 3, with the exception that cover 62 is manufactured of sheet metal and has the form of a conventional jam jar cover, with the difference however that the conventional elastic sealing lining therein is omitted and replaced by a diaphragm 61. This diaphragm 61 is of elastically deformable material, such as plastic, for example thin polyethylene, whereby ribs 59 and ridges 58 are again present. An annular collar 65 is arranged on diaphragm 61 outside container neck 63 and inside cover edge 66. When cover 62 is screwed off the neck 63 on container 64, collar 65 in fig. 5 co-operates directly with the screw edge 68 of cover 62 to remover diaphragm 61 from neck 63. In fig. 6, collar 65 has a collar element 70 hanging from it which co-operates with screw edge 68, this collar element 70 being provided with ridges 71 to ensure the passage of air between collar element 70 and cover edge 66. In fig. 7 hanging fingers 73 are arranged on collar 65 to keep the diaphragm at a constant depth in the cover 62 removed from container 64.

Claims: 1. Closing device (7, 37, 67) for closing a container opening (6) comprising at least a cover (2, 32, 62) arranged over said opening (6) and a diaphragm (1, 31, 61) arranged between an edge (11) of said container opening (6) and said cover (2, 32, 62), said diaphragm being essentially elastically and/or plastically deformable in its plane, preferably having a shape which in unloaded state deviates essentially from the flat form, said diaphragm being provided with a circumferential flange (10, 57) for providing an air tight seal with the edge (11, 63) of the container opening, whereby a space (15, 45) present between said cover (2, 32, 62) and said diaphragm (1, 31, 61) is in contact with the ambient atmosphere via at least one passage (14, 60), said cover being connectable to the container by means of releasable connecting means, characterized in that said at least one passage (14, 60) comprises at least one groove in the upper side of the flange (10, 57) of said diaphragm (1, 31, 61) and extending across said flange (10, 57), so as to communicate said space (15, 45) with the ambient atmosphere. 2. Closing device (7, 37) as claimed in claim 1, characterized in that the diaphragm (1, 31) has at least one groove (14) between diaphragm (1, 31) and a circumferential lip (46) which is arranged on the inside of the cover (2, 32) and which is arranged for sealing engagement with the opening edge of the container (4), when said diaphragm (1, 31) is removed. 3. Closing device (67) as claimed in claim 1 or 2, characterized in that the cover (62) is manufactured of a stiff material, for example metal, and that said diaphragm (61) is provided with coupling means (65, 70, 73) for coupling said diaphragm (61) with said cover (62). 4. Closing device (67) as claimed in claim 3, characterized in that the coupling means (65, 70, 73) are arranged on the outer periphery of the diaphragm (61). 5. Closing device (67) as claimed in any of the preceding claims, characterized in that the diaphragm (61) is provided on its outer periphery with downward hanging coupling means (70, 73) which co-operate for coupling with an edge (68) of the cover (62). 6. Closing device (67) as claimed in claim 5, characterized in that the coupling means consist of downward hanging fingers (73). 7. Diaphragm (1, 31, 61) for use in a closing device (7, 37, 67) according to any preceding claim, said diaphragm being essentially elastically and/or plastically deformable in its plane, preferably having a shape which in unloaded state deviates essentially from the flat form; said diaphragm being provided with a circumferential flange (10, 57) for providing an air tight seal with the edge (11, 63) of a container opening; characterized by said diaphragm comprising at least one groove (14, 60) in the upper side of said flange (10, 57) and extending across said flange (10, 57), so as to communicate a space (15, 45) to be provided between said diaphragm and a cover of said container (4) with the ambient atmosphere.

Inventors: KILLESTIJN, CORNELIS
Applicants: SKILLPACK B.V.
Application year: 1988
Main classification: B65D51
IPC codes: B65D79