DE69023756T2 - Locking device. - Google Patents

Description

The present invention relates to a closure device for closing an opened can for a carbonated beverage.

Carbonated drinks, also known as fizzy drinks, are sold in cans that traditionally have a ring-pull opening mechanism. When a ring attached to the top of the can is pulled, part of the top of the can is removed, creating a hole through which the drink can be dispensed. One problem with such cans is that the ring-pull opening cannot be resealed. So if you only want to drink part of the can's contents, the rest of the contents cannot be kept fresh. Furthermore, if the can is carried around or transported in a moving vehicle, there is a risk of the contents spilling.

The shape of the opening exposed in the top of the can when the ring is pulled varies from manufacturer to manufacturer. In some cases the ring remains on the can and because of these differences it is not practical to provide a reclosable top which cooperates with the opening itself, although proposals aiming at this function exist (see for example EP-B-0 112 306 and GB-A-2 210 028). A closure device according to the introductory part of claim 1 is known from US-A-4 752 016.

According to the present invention, a closure device for closing a dispensing opening of an opened can for a carbonated beverage is provided, which has a top having an outer rim and an inner rim, an annular groove between the two rims and an upper surface within the inner rim in which the opening of the can is located, the device comprising a cap and a cap-like base adapted to engage the bottom of a can, characterized in that the device comprises a flexible sealing ring secured in the cap and adapted to form a circumferential pressure-tight seal against the inner rim of the can, and mating screw threads on the cap and the base, the threads being screwably engaged together so that a clamping force is generated in the device between the bottom of the can and the cap which draws the seal against the inner rim of the can around its entire circumference, thereby sealing the opening of the can from the atmosphere and preventing escape of the pressurized gas from the can to the atmosphere.

Many cans for carbonated drinks have an outer and an inner rim, an annular groove between the two rims and an upper surface within the inner ring in which the opening of the can is located. Such cans can be closed with the device of the invention.

The seal preferably has a diameter of between 50 and 60 mm so that it seals the edge of a conventional beverage can.

The seal may be formed by a flexible sealing ring mounted in a lid. The sealing ring may be pressed into an annular socket in the lid. Alternatively, the lid may have an internal integral structure forming the flexible sealing ring.

The device consists of two parts, i.e. a cap which carries the seal and a cap-like body. The body is located under the bottom of a can or on a ledge near the bottom of the can and the cap and body can be attached to each other in such a way that a pulling force is created in the device between the bottom of the can and the cap which draws the seal to the edge of the can. This force is counteracted by a compressive force created in the walls of the can.

Since the gasket seals a peripheral ring portion of the can that is concentric with the can itself, the cap can be secured to the body by threading threads formed on the cap and body together. The axis of rotation on which the screw threads are screwed together corresponds to the axis of the cylindrical can. The complementary threads provide part of the gasket fastening means that creates the desired pulling force in the device. A stop can be provided to prevent over-tightening that could result in crushing the can.

To allow rapid release of internal pressure, a valve may be provided in the cap. This valve may operate automatically and release pressure above a certain threshold pressure, or may be operated by the user, for example so that the pressure can be released before the cap is opened.

The body and cap may be provided with thermal insulation to keep the can and its contents cool. The insulation may form an integral part of the material of the body and/or cap or, alternatively, may consist of a filling between an inner and an outer skin forming the body and cap. Drainage holes may be provided in the body if desired. a thermally insulated device so that condensate can drain away.

The outer wall of the cap and the wall of the body may be provided with ribs or the like to facilitate the screwing together and unscrewing of the cap and body. Alternatively, either the body or the cap or both may have openings formed in their walls. This may help to prevent the formation of condensation on the wall of the can and provide a grip for the hands, as well as exposing part of the can itself so that the can can be seen inside the device.

If the device is to be used with cans of different lengths, the base body may be designed to accommodate the largest can and if a smaller can is to be used, an adapter body may be fitted in the base body before the can is inserted to fill the excess length. The adapter body may be made of or contain a material which is frozen before use and is in contact with the can to keep the can cool.

The invention will now be further described by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a side view of a conventional effervescent beverage can;

Fig. 2 is a perspective view of the top of the can in Fig. 1, with the can opened;

Fig. 3 shows a section through a closure device according to the invention, with the can in Figs. 1 and 2 being inserted;

Fig. 4 is an external view of the closure device in Fig. 3 ;

Fig. 5 is a detail of part of the cap of Fig. 3;

Fig. 6 is a view corresponding to Fig. 5, but showing a second embodiment;

Fig. 7 is a section through a third embodiment of the closure device according to the invention;

Fig. 8 is a section through a fourth embodiment of the closure device according to the invention;

Fig. 9 is a detail of a thread form for use with the closure device of the invention; and

Fig. 10 is a detail of part of the structure of the fourth embodiment.

The can shown in Fig. 1 has a top 1, a base 2 and side walls 3. The top has an outer rim 4. At the top of the can (see Fig. 2) a channel 6 surrounds an upper surface 5, with an inner rim 7 forming the outer edge of the upper surface. A ring-pull closure 8 can be pulled to open a dispensing opening 9.

The closure device shown in Fig. 3 to 5, which represents a further development, consists of a base body 10 and a cap 12. The base body and the cap define a cavity which is dimensioned to accommodate standard-sized beverage cans, such as a 330 ml soda can as shown in Fig. 1 and 2. The base of the can sits on the base 14 of the base body 10. The cap 12 has two inner webs 18b and 18c which form a socket into which a sealing ring 37 is fitted. When the cap 12 with the thread 16 is fitted onto the base body is screwed on, the inner annular web 18b on the cap 12 comes into contact with the inner surface 20 of the outer rim 4 on the can 22 to form a seal, and the flexible sealing ring 37 lies sealingly against the top of the can. The thread 16 can be a coarse thread with several turns.

The ring pull closure of the can 22 is removed so that the top of the can has an opening 24. This opening now communicates with a space 26 above the can, but this space is limited by the seal formed between the ring 37 and the top of the can and between the web 18 and the side surface 20. When the can is shaken, a certain amount of liquid from the can can escape through the opening 24 into the space 26, but cannot flow further and due to the nature of the seal between the web and the side surface, the can is kept pressure tight. If the can has a ring pull closure of the type which remains on the can as can be seen in Fig. 2, this ring pull closure can be accommodated in the space 26.

Fig. 4 shows the exterior of the closure device. From this figure it can be seen that the base body 10 has oval-shaped cutouts or openings 36 through which the can inside the device can be seen and which also allow the circulation of air around the can, which prevents the formation of condensation on the outside of the can. Figs. 3 and 4 also show a shoulder 38 on the base body 10 which limits the screwing-on movement of the cap 12 and thus prevents it from being tightened too tightly.

Fig. 5 shows the sealing construction of Fig. 3 in detail. The can 22 has an upper surface 5, an annular groove 6 around the outside of the surface 5, an inner rim 7 and an outer rim 4. The cap 12 of the closure device has two inner webs 18b and 18c. Both webs lie inside the circle of the rim 4 and define a annular socket into which the sealing ring 37 is fitted. As already indicated with reference to Figs. 3 and 4, a first seal is formed between the web 18b and a side surface 34 of the rim 4, and a second seal is formed between the inner rim 7 and the sealing body 37.

In Fig. 6, the cap 12 has two inner ridges 18d and 18e which form an annular socket which receives an annular sealing ring 37a. The ridge 18d is shorter than the ridge 18b of Fig. 5 and does not itself form a seal. The sealing function in this embodiment is entirely performed by the ring 37a. However, the lower edge of the ring 37a is shaped to form a primary seal on the inner rim 7 and a secondary seal by the engagement of an outer lip 39 with the channel 6. A rib 41 is also pressed against the upper surface 5 of the can 22 to improve the "grip" felt by the user when screwing on the cap 12.

Although the closure devices shown in the preceding figures do not aim to provide any thermal insulation of the can, such insulation can easily be incorporated into the device. Fig. 7 shows a base body 10c and a cap 12c, both of which have an inner and an outer skin 60, 62, with a thermally insulating layer 64 located between the skins.

The inner and outer skins 60, 62 are separate molded parts (two molded parts for the body and two molded parts for the cap). The thermal insulation 64 is manufactured as a separate prefabricated component sized to fit comfortably in the cavity between the inner and outer skins. Manufacturing the insulation in this manner rather than by foaming on site allows for a quick and reliable assembly process that does not require a waiting period while the foam forms and hardens. After the three parts (inner skin, insulation and outer skin) have been assembled, the inner and outer skins are firmly joined together by an ultrasonic weld around the joint 66.

The outer skin 62 of the base body 10 also has drainage holes 68.

The inner skin 60 of the base and cap includes the threads that connect the two parts and also the gasket that, in use, seals the top of a beverage can. In Fig. 7, the webs 18d and 18e (see Fig. 9) are shown, but the sealing ring 37a of that figure is omitted. Fig. 7 also shows axial ribs 70 that help center the cap when it is screwed onto the base with the can inserted.

The threads 16 which connect the cap and the body together are preferably multi-start threads (there may be three starts, for example), and the thread profile as shown in Fig. 9 has been found to be suitable. There is axial play between the flanks of the threads until the cap is screwed tightly onto a can, at which point the play is eliminated.

Fig. 8 shows an insulated closure device with many of the features already described with reference to Fig. 7. In Fig. 8, the sealing ring 37a is shown inserted. The base body 10c does not differ from that shown in Fig. 7, but the cap 12d has a pressure relief opening 72 which is normally closed with a screw cap 74.

When an opened beverage can is in the closure device, a fairly high pressure can develop. When the pressure is high, the flanks of the thread 16 are pressed tightly together, and it may be difficult to unscrew the cap from the body. To solve this problem, the opening 72 can be opened by removing the screw-on cap 74. This releases pressure and the cap 12d can be unscrewed.

The opening 71 can also represent a drinking opening.

The screw-on cap 74 may have a non-circular shape so that it can be easily gripped and turned.

The opening 72 can be easily integrated into the manufacturing process by forming the walls of the opening 72 as a unit with the inner skin 60, making a suitable cutout in the insulating foam 64 and the outer skin 62 and then passing the outer skin over the spout-like end of the opening 72 in the manner shown in Fig. 10, with the outer skin 72 snapping under an outer bead 78.

Fig. 8 also illustrates the use of an adapter body 76 which can be inserted into the bottom of the base body 10c when the device is to be used with a smaller can. When the adapter body 76 has been inserted, the bottom of the can can rest on the top of the adapter body so that the top of the can is located in the correct position with respect to the cap 12d. The use of such an adapter body or a series of adapter bodies of different sizes enables a device to be used with cans of a corresponding size range.

The adapter body 76 may contain a material that is easily frozen and serves as a cooling device in the body under the bottom of the can and in heat-transferring contact with the bottom of the can.

The closure device shown in the various versions of the drawings is simple and effective to use and, firstly, seals the opened can without allowing gas to escape, which could cause the drink to go stale. It is useful if the can sits firmly in the base body 10 so that when the cap has been unscrewed, the can can be grasped by the base body.

The components of the closure device can be easily molded from plastic material. Food-grade polypropylene, such as that sold by Repsol of France under the trademark Isplen and the designations PP/080 and PP/095, has been found to be suitable. A suitable rubber for the sealing ring inside the cap is the thermoplastic rubber sold by Monsanto under the trademark Santoprene, Grade 177.

An important aspect of the invention is that the force required to make and maintain a seal around the open portion of the can is created by placing a counter-pad under the bottom of the can and then applying tension to connecting means which connect the seal to the counter-pads. The counter-pads need not completely enclose the bottom of the can; they may only grip under part of the can bottom or, if the can has a stepped bottom structure as at 43 in Figure 1, the counter-pad may grip under the step at the bottom rather than fully engaging under the bottom.

Claims (6)

1. A closure device for closing a dispensing opening (24) of an opened can (22) for a carbonated beverage, having a top with an outer edge (4) and an inner edge (7), an annular groove (6) between the two edges (4, 7) and an upper surface (5) within the inner edge in which the opening (24) of the can (22) is located, the device comprising a cap (12) and a cap-like base body (10) adapted to engage the bottom of a can (22), characterized in that the device comprises a flexible sealing ring (37, 37a) secured in the cap (12) and adapted to form a circumferential pressure-tight seal against the inner edge of the can (22), and mating screw threads (16) on the Cap (12) and the base body (10), the threads being able to be screwed together in such a way that a clamping force is generated in the device between the bottom of the can (22) and the cap (12), which pulls the seal (3/, 3/a) against the inner edge (7) of the can around its entire circumference, whereby the opening (24) of the can is sealed against the atmosphere and escape of the compressed gas from the can to the atmosphere is prevented. 2. A closure device according to claim 1, characterized in that a valve (72, 74) can be provided in the cap (12) to enable rapid release of the internal pressure in the device. 3. A closure device according to claim 1 or claim 2, which has enclosure-forming walls (10, 12) in in which a can can be arranged, characterized in that the walls are provided with thermal insulation (64) to keep the can and its contents cool. 4. A closure device according to claim 3, characterized in that the insulation is provided by a filling (64) between inner (60) and outer (62) skins forming the walls of the enclosure. 5. A closure device according to any one of the preceding claims for use with cans of different lengths, characterized in that a base body (10) of the device is designed to accommodate the longest can size and is combined with an adapter body (76) which is arranged in the base body prior to the introduction of a shorter can in order to take up the excess length of the base body. 6. A closure device according to claim 5, characterized in that the adapter body consists of a material or contains a material which is freezable before use and is in contact with the can to assist in cooling the contents of the can.