FI68580C - INTRYCKBAR TRYCKUTLOESANDE TILLSLUTNING - Google Patents

Description

r p_ _ KU RELEASE PUBLICATION, 0 c Q n ji B 11 UTLÄGG Nl NGSSKRIFT 685 8 0 C (45) PctcnttI granted 10 10 19S5 Patent moidclut ^ ^ (51) Kv.lk.4 / lnt.CI. * B 65 D 17/28 FINLAND - FINLAND (21) Patent application - Patentansökning 78 1 599 (22) Application date - Ansökningsdag 19.05-78 (FI) (23) Starting date - Giltighetsdag 19-05-78 (41) Has become public - Blivit offentlig 11.12.78

National Board of Patents and Registration / 44) Date of publication and date of publication. —- 28.06.85

Patent- och registrstyrelsen '' Ansökan utlagd och utl.skriften publicerad (86) Kv. application - Int. ansökan (32) (33) (31) Privilege claimed — Begärd priority 10.06.77 14.07.77, 28.-9.77 Australia-Australien (AU) PD 0416, PD 0848, PO 1840 (71) The Broken Hill Proprietary Company Limited , 140 William Street, Melbourne, 3000 Victoria, Australia-Australien (AU) (72) Michael Debenham, Frankston, Victoria, Allan George Da lii, Warran-dyte, Victoria, Peter Lewis Rev ill, Middle Park, Victoria,

Australia-Australien (AU) (74) Oy Koister Ab (54) Pressure pressure regulators - Intryckbar tryckutlösande tillslutning

The invention relates to a pressable closure for a pressure-releasing container for pressurized liquid, comprising a closure part integrally formed in the container part and delimited by at least one weakened line, dimensioned so that it can be opened by a pressure-pushing force, the closure part having an actuating part. and a connection point associated with the container around which said closure member is adapted to pivot during the opening step.

It is generally accepted in canning techniques that a can with a pressable closure for high carbonated beverages requires some form of pressure-releasing vent closure that can at least reduce the internal pressure of the can before opening the spout closure. An example of a pressure control shutter is shown in Figure 1 of the accompanying drawings, in which it is noted that the ventilation shutter V has a smaller surface area than the pour shutter P.

Cans with high carbonated beverages, including those with air vents such as those shown in Figure 1, tend to burst or spray when opened, especially if the beverage in the can tends to foam. The problem is exacerbated if the can is tilted when opened, as this often means that the liquid in the can is either close to or flushed by the vent closure, making it more likely that the escaping gas will bring some liquid or foam from the can. The problem is even worse if the can is handled violently before it is opened, because shaking causes the release of carbon dioxide into the end of the can, thus developing foam. U.S. Patent 2,261,117 to Jack Jr discloses a printable closure comprising a single closure member. The closure portion is made by forming a bulge in the container portion, separating the bulge into a separate convex strip, and flattening the convex strip so that its cut edges and the edge portion surrounding the opening overlap. U.S. Patent 3,333,475 to Klein et al. Discloses a can lid with a hatch in which the hatch can be pressed into the container by finger force. The container has a single hatch, but in column 4, lines 62-66, the patent holders describe an arrangement in which a portion of the hatch plate can be bent inwardly at each end to form a special pouring portion and a ventilation portion with the hatch portion between the portions in place. Klein, etc. do not present or suggest a resealable ventilation section.

U.S. Patent 3,741,432 to Werth et al. And Australian Patent No. 475,951 each disclose a container closure strip in which a pressure release strip is disposed on the closure strip. When the pressure release strip is pressed by hand, the effect is transferred to the shutter strip. Both the pressure release strip and the shutter strip are printable by the user's thumb pressure which is applied to the pressure release shutter strip and moves to the shutter strip in a single step which first opens the pressure release hole and then the shutter hole or opening. Werth et al. Do not suggest that the pressure relief strip shown would close again when the finger pressure is released.

In fact, it is Werthin Jie. the entire focus of the patent is to get the pressure to release and the spout to open in a single step without taking your finger off the strip.

U.S. Patent 3,759,206 (Re 28,190) and 3,931,909 are directed to printable, easy-open closures, for example, for containers such as metal beverage cans; The patents disclose easy-open closures for making by bulging a portion of the can end or other portion of the container and cutting a strip from the container portion so that at least a portion of the bulge is on and around the outer side of the strip. After the separation or cutting step, the bubble surrounding the opening is flattened so that the metal overlaps with the cut edges of the strip.

Yesterday's U.S. Patent 3,958,717 discloses a printable, easy-open closure comprising a pouring strip and an air exchange strip. The strips are integrally connected by a hinge portion of the can lid so that the strips exit in opposite directions from a common hinge area. Applicants show that this structure resembles a conventional ring-pullable end in appearance, so that no special advice is required to guide the consumer, and since the strips are also in close proximity, the can can be opened with very little finger movement. There is no indication that the ventilation strip closes when the finger pressure ceases.

U.S. Patent 4,033,275 to Radke discloses a beverage can end having a ventilation strip and a pouring strip that are substantially similar to U.S. Patent 3,985,717, except that the strips do not have a common hinge area, but are instead shown to be separate.

It is therefore an object of the present invention to provide improved forms of pressure relief closure which at least alleviate or make more manageable the problem of bursting and spraying.

This is achieved by means of a closure according to the invention, characterized in that the closure part, the connection point and / or the part of the container surrounding the closure part are adapted to provide means for substantially preventing permanent opening of the closure part by finger-pushing, the closure part being adapted to return substantially closed. to its position when the pushing force produced by the finger force has been removed.

It is clear from the above that since the shutter does not remain open except when gravity acts on the drive part, bursting and spraying cannot continue when the force is removed. In addition, because the force of gravity must be used to keep the closure open, any liquid or gas coming from the closure will be deflected by the finger or thumb that causes the force.

In the case of the prior art arrangement shown in Figure 1, the person opening the closure tends to have his fingers removed from the closure when spraying begins, allowing in the worst case the liquid to be discharged to form a shower well.

An improved pressure relief shutter can be provided in many ways. For example, it is possible to select how much the operating part is lifted and / or the effective area of the pressure-releasing closure available for operation, so as not to increase the deflection caused by the finger force beyond the angle at which the elastic limit of the metal in said joint is exceeded. opening due to thumb pressure. Alternatively, the joint may be placed remotely on the circumference of the drive member and the closure may not be opened sufficiently to allow the metal forming the joint to pivot beyond its elastic limit.

In a particularly preferred embodiment of the invention, the pressure relief closure is located at the narrow tip of an approximately pear-shaped spout closure hinged at its wide end, said pressure-releasing closure being partially separated from said spout closure, except for a short connection around which preferably raised to such an extent or its effective size is such that it is not permanently opened by the pressure of a finger or thumb.

In the case of the arrangement shown in Figure 1, it is likely that the thumb or finger will cover the opening created by the km air exchange shutter being opened. This has been found to cause detrimental opening properties caused by the user, as the user tends to remove the thumb or finger as soon as he notices the gas escaping. In the preferred arrangement described above, gas discharge can occur as soon as the shutter is opened, while discharge of the spray liquid can again be prevented by removing the force opening the shutter and achieving controlled discharge by releasing gas and / or foam as short jets.

In another preferred embodiment of the invention, the pressure-releasing closure is made as an extension of the pouring closure, so that the respective closures close the openings, which are preferably connected as one opening. In this arrangement, the pressure-releasing closure operates as described above, however, so that it disengages from the opening when the pouring closure is opened, thus forming an air opening through which air flows into the can during the pouring step.

5,68580 In a preferred embodiment of the present invention, the drive member is located at one end of a relatively narrow, long portion that extends from the connection of the container member. With this arrangement, it is unlikely that the finger or thumb causing the opening force will cover the entire closure, leaving an exit path for the gases escaping from the container. For all embodiments of the present invention, it is critical that the closure not be pushed into the corresponding opening so deep that the resilience limit of the closure is exceeded. If the closure is pressed into the beverage can or other container by finger force and the closure is bent around its joint without exceeding the elastic limit of the joint, the closure will at least substantially return to its original position and thus reseal the container more from leaking foam or liquid. The pressure inside the tank helps to reseal the closure.

The exact amount of deflection that a particular closure can withstand without exceeding the elastic limit of its joint depends on a number of variables such as the size of the closure, metal thickness, metal type, effective joint length, etc. In general, it is not possible to determine the exact closure deflection allow before the joint elastic limit is exceeded. However, the basic conditions for the amount of angular deflection of the shutter can be more easily understood by considering the following simulated experiment.

The closure was made on 5082 aluminum sheets with a thickness of 0.38 mm. The closure had the structure shown in Figure 6 with a central section at a distance of 0.11 mm from the center of the closure. The free or cut edges of the shutter were about 0.38 mm from the center of the shutter. The end of the closure furthest from the joint was bent into the simulated can by 0.76 mm, which corresponds to a bending angle of 5.5 °, and when the bending pressure was removed, the closure returned to approximately its original position. After a deflection of 0.89 mm, the shutter still returned to its original position, i.e. the elastic limit of the joint had not been exceeded. However, when the shutter was pressed 1.02 mm, which corresponds to a bending angle of 7.5 °, the joint bent permanently and the shutter did not return to its original position.

The simulated test was performed by attaching the shutter at the hinge and applying a force to the free edge of the shutter furthest from the hinge.

The results of these tests show that the angle of movement of the shutter must not exceed 7.5® and preferably less than 5.5-6.0 °. The deflection must, of course, be large enough to release the pressure from the 6 68580 container, and the minimum deflection by which this is achieved depends on a number of variables, such as the thickness and type of sealant used in the separation line.

In actual use, consumers, whose habits can vary widely, may sometimes leave a slight permanent deformation in the joint or hinge, but this is unusual (perhaps caused by a particularly heavy user) and nullified by the pressure inside the can, especially if it contains carbonated malt beverages.

In order that the invention may be more readily understood, several preferred embodiments will now be described with reference to the accompanying drawings, in which; Figure 1 is a plan view of a can end according to the prior art; Fig. 2 is a plan view of a simple embodiment showing the principle of operation of the embodiment compared to the prior art end, Fig. 3 is a plan view of a preferred embodiment of the invention, Fig. 4 is an enlarged partial vertical section 4-4 of the end of Fig. 3, Fig. 5 is a schematic partial vertical section for making the closure of Figs. Fig. 6 is a plan view of a modification of the embodiment of Fig. 3, Fig. 7 is a plan view of another preferred embodiment of the invention, Fig. 8 is an enlarged partial vertical section 8-8 of Fig. 7, Fig. 9 is a plan view of another embodiment of the invention, Fig. 10 is an enlarged partial vertical section 10- Fig. 9 is a partial plan view of a modification of the embodiment of Fig. 9, Fig. 12 is a schematic representation of a closure manufacturing step of the closure of Figs. 9 and 10, Fig. 13 is a schematic view similar to Fig. 12 showing a modified manufacturing method, Fig. 14 is a plan view of another preferred embodiment of the invention. Fig. 15 is a vertical section 15-15 of Fig. 14; Fig. 16 is a partial vertical section of the closure of Figs. 12 and 13 made in the recess of the flat end plate.

68580

Referring first to Figure 1 of the drawings, in the prior art can shown in Figure 1, there is a pressure release of a discharge closure V and a pouring closure P. Each closure is circular and integrally hinged to the end of the can at the circumference of the closures. Thus, when the shutters V and P are opened, they turn around H, and since the opening force bends the shutters to a position such that the elastic limit of the metal forming the hinge is exceeded, the shutters remain open once opened. In the case of the closure V, it has a strip higher than the pouring strip to ensure that it can be pushed open enough to provide adequate ventilation during pouring. In the simple magic diagram embodiment shown in Figure 2, the discharge closure V is replaced by a pressure release closure 10. The closure 10 comprises a closure part or strip 11 with a drive part 12 in the form of a raised knob by which the opening force can be applied to the closure 10 with a finger or thumb. The strip 11 is relatively long and narrow in shape compared to the discharge opening V and is integrally connected to the end at 13. The joint 13 does not function as a hinge in use in the same way as the hinges H in Figure 1 and is therefore called a joint instead of a hinge.

The closure member 11 is fully cut in construction, as described in U.S. Patent Nos. Re 28,910 (3,759,206) and 3,931,909, the disclosures of which are incorporated herein by reference and are made by the method described therein or by stamping or otherwise widening the strip and / or reducing the opening. assemble by any cold working step, such as stamping.

When opened, a force is applied to the raised part 12 with a finger or thumb. Since the connection 13 is remote from the part 12, it is unlikely that the finger would cover the entire closure and the gas flow openings are free at least on the long sides of the strip 11. In addition, the remote location of the joint 13 means that the angle to which the strip 11 can be bent by the force exerted by the finger is not so great that the elastic limit of the metal is exceeded at the joint 13 so that the strip returns to its at least substantially closed position, 8 68580 when the opening force is removed. any pressure or leaking contents in the can. Together, these two factors mean that in the event that spraying occurs, it can be controlled by the shutter 10 by removing the opening force and releasing the gas and / or foam out in short bursts.

In practical embodiments, the closure 10 is likely to be located closer to the center of the end of the can to make it less likely that there will be liquid among the gas released from the can. Furthermore, it will be appreciated that in any commercial embodiment, the closures 10 and 11 are hermetically sealed with a sealant (not shown) such as plastisol, which is applied to the end by any suitable method.

Despite the ability of the above-mentioned embodiment to at least reduce the problems associated with the prior art, one practical difficulty is provided in that the closure 10 does not act as an air hole for the can when pouring or soldering liquid from it after the opening force has expired. However, the problem can be avoided by using any of the shutter shapes shown in Figures 3-14.

The end of the can shown in Figures 3 and 4 is made so that the fully cut closure portion is surrounded by an approximately pear-shaped opening 21 and hinged to the end at 22. The raised end 23 of the strip 20 has a raised portion 23 and a smaller raised portion or knob 24 near the narrow end of the strip 20. The narrow end of the strip 20 is partially separated from the rest of the strip along lines 25 and 26, leaving a narrow connection 27 and thus defining a pressure release strip 28. The knob 24 in the strip 28 is higher than the part 23 so that it is more easily accessible by finger or thumb. The strip 28 may be, for example, 1 mm above the surroundings of the strip 20, and it can be seen from the drawing that the strip 20 is at the same level as the raised circumference of the opening 21. The dividing lines 25, 26 allow the pressure release strip to flex around the joint 27 while the height of the strip 28 is chosen to prevent permanent deflection after the opening force caused by the finger or thumb has been removed. When the opening force is released, the strip 28 closes to prevent continuous spraying in the event that spraying occurs. After the pressure in the can has been released, the strip 20 can be easily opened by pressing the raised part 23 of the strip 20 with a finger. As in the previous embodiment, all the separating lines of the closure 9 68580 are covered with a sealant (not shown). Both to protect the strips 20 and 28 from accidental opening and to stiffen the end for pressure buckling outwards, it is desirable to make the closure so that the end has a recess 29. The recess 29 can be formed by making the end plate slightly convex, e.g. 1.5 mm and then flattening the dome. Alternatively, a recess 29 can be formed in the flat end plate. In this way, the higher part of the end part protects the strips 20 and 28 and the plate stiffens against buckling.

Considering the above description, it will be clear that the embodiment of Figure 3 effectively connects the separate pressure relief strip of Figure 2 to the pouring strip, so that the strip 20 itself defines the connection between the pressure release strip 28 and the end of the can. By effectively connecting the pressure relief port and strip to the pouring port and strip, the discharge port opens when the strip 20 is opened, thus eliminating the problem caused by the reclosing property of the pressure relief strip 28. However, until the strip 20 is opened, the pressure relief strip operates as described above, thereby alleviating the problems associated with the prior art at least to the same extent as in the first embodiment.

Due to the shape of the opening 21, the pouring and drinking properties are satisfactory. The closure is manufactured by a modified method compared to the patents referred to above.

When making ends at high speed, it is not appropriate to separate the strip 20 and make slots 25 and 26 for different tools and at different stages.

Thus, with reference to another aspect of the invention, there is provided a method of manufacturing a closure strip having separation lines transverse to the strip separation line itself, the method comprising separating metal along said transverse lines from the main tool in the main ice separation stage.

In use, it separates the transverse lines mentioned at the beginning of the step on the metal plate and partially separates the strip of their adjacent part. The sliding tool part is then pressed into the die, whereby the remaining part of the strip separates.

A device suitable for making a closure is shown schematically in Figure 5, which is a partial vertical section of the tool parts.

10 68580

The tool comprises a main tool 40 having an aperture-shaped cutting surface 41 and a sub-tool 42 slidably mounted on the main tool and pushed into the position shown by a spring 43. The sliding portion has two cutting surfaces 44, only one of which is visible to form dividing lines 25, 26. A stepped puncture 45 having cutting surfaces 46 corresponding to the cutting surfaces 44 is mounted so as to engage the sliding portion 42 and separate along lines 25 and 26 and separating the circumference of the pressure relief strip 28. The needle 45 then presses the sliding portion into the matrix 40, after which the needle 45 separates the remaining portion of the strip 20 from the end.

The metal plate, which is displaced upon separation along lines 25, 26, returns to the same plane as the remaining plate to ensure that the circumference of the strip is substantially flat. If necessary, metal can be punched on either side of the dividing line to ensure that the cracks do not open.

If necessary, the edge of the strip 20 and / or the periphery of the opening 21 can be stamped or otherwise machined to increase the overlap between the strip 20 and the surrounding metal.

Figure 6 shows a modification of the closures of Figures 3 and 4.

In this variant, the separation lines 25, 26 have been replaced by a central separation line 25 ', which leaves two separate joints 27' between the pressure relief strip 28 'and the main strip 20'. The closure is otherwise identical to the embodiment of Figures 3 and 4 and operates in exactly the same manner. However, it has the advantage that its circumference is not separated and is more compact than the embodiment of Figure 3, where leakage may occur if the separation lines 25, 26 shift. In addition, the uncut perimeter of Figure 6 simplifies the operation of the tool in the manufacture of the closure. In this case, the center separation line can be made by a so-called side cutting step.

The closure of Figure 6 is manufactured as follows. The end plate is bulged outwards by about 1.5 mm by pressing or stamping along the circumference of the end plate near the counter-dips. The point where the closure is made is flattened and the metal plate is raised from the point where the pressure release strip 28 will be made. The strip 20 'is then separated and pre-inflated as described in the above patents. At the same time, the strip 20 'is raised with a die and the metal is cut locally around the edge of the die. The bulged plate around the opening is then flattened so that the strip and the surrounding plate overlap and all the separation lines are treated with a sealant.

If necessary, metal can be stamped on either side of the edge of the die to ensure that the seam does not open. Alternatively, notches can be made in the contouring point so that the above cut is interrupted in a short distance. It is clear that a weakened line, for example a score line, can also be used instead of a cut. Again, the circumference of the strip and / or the metal surrounding the opening can be stamped to increase the overlap between them.

The end of the can shown in Figures 7 and 8 is made with a fully cut closure comprising a spill section or strip 31 hinged to the end at 32 and below the spout 33 and a pressure release / ventilation section or strip 34 connected to the spout. via a common neck 35 and which leaves the pouring spout radially under the ventilation opening 36 which joins the pouring opening 33 through the neck 35. The strips 31 and 34 are raised with the strip 34 higher so that it is more exposed to the finger or thumb. For example, the strip 34 can be raised about 1 mm higher than the circumference of the strip, and it can be seen from the drawings that the strip 31 is flush with the raised circumference of the opening 33.

The above closure is made by the same method as the closure 10. If necessary, the circumferences of the strips 31 and 34 and / or the openings 33 and 36 can be stamped or otherwise machined to increase the overlap between the strips and the surrounding metal.

The embodiment of Figures 7 and 8 effectively combines the separate pressure relief closure of Figure 1 with a known pour closure, the strip 31 forming a connection between the pressure relief closure 34 and the end of the can. In use, the discharge closure 36 opens when the pouring closure is pressed, thus eliminating the problem caused by the reclosing feature of the pressure relief closure 34. However, until the spill shutter 31 is pressed, the pressure relief shutter operates in the same manner as described above and therefore alleviates the problems associated with the prior art at least to the same extent as the first embodiment. Both to protect the strip 34 from accidental opening and to stiffen the end against an outward buckling due to pressure, a brush R is made at the end, for example as shown in Figures 7 and 8. the shape and position of the brush as shown in the drawings, the invention is not I a woman 68580, because it is proven that many others, shape and location of one or more of the brush or the bead can be just as effective for these purposes. It is also clear that similar protective brush (es) may be associated with the arrangement shown in Figure 2.

Also, the location of the hinge 32 as shown in Figure 7 is not essential or even necessarily the most popular.

The hinge may be located at the point shown in Figure 7 or directly opposite the point shown in Figure 7.

Similarly, the particular shape of the combined closures 33 and 36 is not essential to the invention.

The softly rounded shape of the opening at the neck 35 is popular for aesthetic and practical reasons and is believed to promote good beverage and pour properties.

The end of the can shown in Figures 9 and 10 has a completely cut closure portion or strip 50 that overlaps approximately the metal surrounding the main annular opening 51 and is hinged to the end at 52. The strip 50 has a center 53 that is elevated relative to the strip environment. It should be noted, however, that the raised point 53 is at the same general level as the plate defined by the hinge 52, whereby the hinge metal does not substantially change its shape in the closure manufacturing process, which will be explained in more detail below. Experiments performed so far appear to show that the unmodified metal at the hinge 52 increases the pressure at which the rise or bulge occurs in this general area of the end.

Strip 50 has a pressure relief closure or strip 55 positioned therein as shown in Figures 9 and 10. Strip 55 has a raised knob 56 at the end of a fairly long, narrow metal portion defining the strip. The strip is hinged to the metal plate of the strip 50 at position 57 and is overlapped under the metal plate surrounding the opening 58. Both closures are hermetically sealed with a sealant (not shown) and the pressure release closure-Jin acts in the same manner as the pressure release closures referred to in the experience previously referred to. It is clear, however, that in most opening operations, both shutters open with a single, one-way retracting force of 13,68580 applied to the general area of the pressure release knob. In the situation described above, it may of course be necessary to use the pressure relief shutter several times. However, the user does not need to move his finger for the final opening step, where the strip 50 fully opens. If desired, the strip 55 can be placed in an inverted position, near the narrow end of the strip 50, to ensure that no finger needs to be moved when the strip 50 is opened.

A further modification of the embodiment of Figure 9 is shown in Figure 11. In this closure strip arrangement, the pour closure 50 'is flattened at the poles and is in the inverted position with its hinge near the center of the can lid, the pressure relief strip 55' is in the recess 54 'of the strip 50' identical to strip 55.

By arranging the strips 50 'and 55', the advantage is obtained that the strip 55 'is closer to the center of the end of the can, where there is likely to be more vertical space. The end of the can is notched around the closure 50 '.

The above embodiments of the invention are similar in construction to the closure described in U.S. Patent No. 3,741,432 to Werth et al., Except that the pressure relief strip is made in accordance with the present invention instead of the method disclosed in the U.S. patent. Thus, the closures shown in Figures 9 and 10 have the same advantages over the closure of Werth and others as the prior art embodiments have compared to the prior art shown in Figure 1. In addition, the use of Werth et al., The common hinge area shown in Figures 1 and 3, may have drawbacks in that the recess of the pouring strip 15 causes an additional recess in the strip 21, increasing the likelihood of the hinge breaking, releasing the strip 21 from the can end.

It can be seen from Figures 9 and 10 that the end of the can containing the improved closure is an outwardly convex central plate 60. Although not obviously shown in the drawing, the dome is slightly flat at the top for the reason explained below. The shutters 50 and 55 14 68580 are located in a recessed position 61 extending to the convex end from the hinge point 52 generally parallel to the strip 50. The location of the shutters 50 and 55 in the recess 61 protects the shutter 50 from unintentional use and to a lesser extent

Slight flattening of the dome of the end plate 60 increases the height of the dome at the point where the pressure relief closure 55 is, thereby increasing the protection provided to the pressure relief closure 55 in the region of the end plate near it.

It can be seen from the vertical section of Figure 10 that the end of the knob 56 is on the same general plane as the metal plate surrounding the center plate.

The end plate is preferably convex for the following reasons as well. The convexity of the end plate increases the top space of the can in which the end is mounted. The convexity of the end plate also increases the buckling strength of the end. In experiments with flat ends, it was found that the convexity of 1.5 to 3.0 mm at the end in addition to the buckling strength of the end. Lom strength increased with convexity.

The closures 50 and 52 and 50 'and 52' may be made by any suitable method of punching and shaping the metal blank of the end blank of the can. Under normal conditions, the method used would involve several separate compression steps, and the puncture / pad combinations used would require conventional release plates and ejectors to ensure separation of the metal plate and the punch and pad parts. The use of release plates and ejectors complicates the needle / pad assemblies and it is obvious that the number of work steps is expected to be reduced.

A preferred method of making an improved closure will now be described. In the first step, an end plate is formed so that it has a slightly flat dome. In the second step, the hood is pressed down to form the recess 61 and to form a small pit at the point where the knob 56 enters. The well is then made into a flat knob 56 by flattening its end between two tools. In the fourth step, the strips 50 and 55 are cut and in the same step the edges of the strip 50 are turned down to form the raised area 53. This step is schematically shown in Figure 12, which is a partial sectional view across the strip 50 but does not show the strip 55. As mentioned above, the center of the strip remains at the same general level as the uncut metal forming hinge 52. In the fifth step, the plate shoulder formed by the cut portion of the sides of 61 is turned down and the side angle with respect to the end plate is increased to provide some adhesion to the strip 50 and between the metal plate surrounding the opening. Finally, the edges of the strip are stamped to increase the surface area of the strip and to further increase the overlap between the strip and the metal plate surrounding the opening. The metal plate surrounding the opening 58 is also punched to provide an overlap between the opening and the pressure release strip 55. The stamping of the edges of the strip 50 is preferably performed as close as possible to the shoulder of the raised portion 53 so that most of the metal expansion occurs outwardly and not back toward the center of the strip. To prevent excessive curling of the edges of the strip during this step, the edge of the strip is pressed firmly between the tool parts. All of the above work steps are well known to those skilled in the art and are therefore not shown in detail in the drawings.

It will be appreciated that in the above description, some of the editing steps have been artificially separated for clarity. In practice, in the manufacture of can ends, certain steps can be combined into a single work step or separated from the steps described above. For example, it is possible to perform the well formation in a separate step.

The method described above for making an improved closure has many advantages. First, the placement of the closure in the recess 61 in the convex central plate protects the closure from unintentional opening. Second, bending the edges of the strip 50 downwardly to allow its center portion to remain at the same level as the hinge 52, and it is believed that this may well improve the resistance of the bent end to pressure. When the strip 50 is made by this method, the pressure relief strip 55 can be cut from the strip 50 in the same operation step without adversely deforming the strip 50. When making the same shutter combination at a flat or raised location on the plate, cutting the strips may result in the edges of the larger strip turning down, which may need to be flattened or repaired in the next step.

While reducing the number of steps of the method described above, the cutting of the strips 50 and 52 can also be combined with the shaping of the metal plate surrounding the openings 16 68580 surrounding the closure 50 and the making of the knob 56. This step performed with a single crimping tool is shown schematically in Figure 13, which is a partial cross-sectional view of the needle / pad assembly at the strip 50, but without the strip 55. As will be appreciated, the needle P has a shoulder and a central recess, while the pad D has corresponding shoulders and recesses for pivoting the strip 50 and the edge 61 downwards.

It has been found that single-step cutting and machining not only reduces work steps, but also makes detachable discs and ejectors unnecessary. The resulting strip and opening have been found to be substantially the same size after the cutting / machining step and, respectively, do not adhere to the pad or needle.

The method described above further has the advantage of maintaining the center portion of the strip 50 at the same general level as the uncut metal plate forming the hinge.

In the second step, a metal plate at the edges of the strips 50 and 55 and a metal plate around the opening 51 are stamped to create the necessary overlap between the strips 50 and 55 and the surrounding metal plate. Alternatively, overlap can be achieved by the methods described in U.S. Patent No. 3,759,206. The cut edges of the strips 50 and 55 are then treated with a sealant to seal both closures hermetically.

The method described above for making an improved machine is popular for several reasons. First, cutting and shaping are performed in the same work step, which reduces the number of steps and makes the removal plates and ejectors unnecessary. Second, the location of the closure in the recess 61 of the central plate protects the closure from unintentional opening. Third, turning the edges of the strip 50 downwards allows the central portion to remain at the same height as the hinge 52, and this is well believed to improve the pressure resistance properties of the convex end. This method of manufacturing the strip 50 also makes it possible for the pressure-releasing strip to be cut from the strip 50 in the same working step without adversely deforming the strip 50.

If the same type of shutter combination is made on a flat or raised sheet metal, cutting the strips may cause the edges of the larger strip to pivot downward, which may need to be flattened or repaired in the next step.

17 68580

It can be seen that in making the closure shown in Fig. 11, the metal plate surrounding the strip 55 is bent downward in the first operation step. This method can also be used to make the transformations described below.

It may be noted that other manufacturing methods may well be used with equally satisfactory results. For example, the plate surrounding the opening 51 can be punched to increase the overlap of the strip 50 and the edge. Alternatively, the overlap between the strip 50 and the seam can be achieved simply by suitably machining the shoulder previously referred to. The overlap between the pressure relief closure 55 and the surrounding plate is preferably formed as described above, as this allows the knob 56 to be made larger and closer to the circumference of the opening 58. However, the necessary overlap can be obtained by stamping the circumference of the opening 55.

It will be appreciated that the various closures described in the previous embodiments may be made in substantially the same manner as the closure in the recent embodiment. In the embodiment of Figures 3 and 6, for example, the area of the recesses can be reduced to the same size as 61 and the protrusion surrounding the opening can be flattened, as shown in Figure 10. In the case of the embodiments of Figures 7 to 8, the location of the closure in the recess would make the protective brushes R unnecessary.

The embodiment of the invention shown in Figures 14 and 15 is a modification of the embodiments of Figures 3 and 4 and comprises a fully cut closure or strip 70 similar to the strip 20 of Figure 3 and hinged to the end at 71. The strip 71 has a pressure relief closure portion or strip 72, defined by dividing lines 73 and 74 and extending on either side of the raised button. Lines 73 and 74 are at an angle of about 60 ° to each other, although it has been found that strip 72 functions well with lines 73 and 74 at any mutual angle of about 30 to 180 °, and preferably at an angle of 50 to 70 °.

The strip 72 bends around the joint of the strip 70 in substantially the same manner as the embodiment of Figures 3 and 4, although it should be noted that the mutual angle of the dividing lines 73 and 74 places the joint 76 farther from the raised button than in the embodiment of Figures 3 and 4.

6 85.80 18

With respect to the strip dimensions and knob height shown in the drawings, the strip 72 cannot be opened in normal use with more than about 3-5 ° finger force, this angle is less than the angle at which the metal at the joint 76 permanently deforms so that the strip 72 returns to a substantially closed position when the opening force is removed.

The strip 70 is in a recess 77 which is formed in substantially the same manner as described above in connection with Figures 9 and 12. However, the manufacturing method of the pressure relief closure 72 has been modified to form the dividing lines 73 and 74. The dividing lines 73 and 74 are formed by a stepped punch at the initial stage of cutting the strip 70. In the same initial stage, the remaining part of the strip 72 is also cut as the movement of the puncture continues downwards, the edges of the strip 70 are turned downwards and the strip 70 is separated, as in connection with Fig. 12. The free edges of the strips 70 and 72 are then brought together so that the strips are flush with the circumference of the strip. The formation of the dividing lines and the inversion of the edges of the strip 70 leave a gap of one material thickness between the strips 70 and 72 in the inner parts of the dividing lines 73 and 74 (see Fig. 16).

Strips 70 and 72 are punched close to their free edges to increase overlap between them and the surrounding metal. The stamping is preferably interrupted at the dividing lines 73 and 74 to ensure free opening of the strip 72 as it pivots around the joint 76. If desired, the recess 77 can be made in the flat end plate, as seen in the sectional view of Figure 16, to provide equally good protection without convexing the end plate. Similarly, the closure structure shown in Figs. 3 and 4 can be made by the method described above instead of the method described in connection with this embodiment or vice versa. In any case, the aim is to avoid moving punching tools.

It is noted that when the pressure relief port and strip are positioned radially inwardly of the pouring port and strip, at or near the center of the end, as shown in Figures 3,6,7 and 14, the advantage is obtained that the pressure relief strip is in the best position to reduce the likelihood of fluid entering the pressure relief valve. above.

19 68580

It should also be noted that in each of the above embodiments, the pressure relief strip and orifice are significantly smaller than the prior art end discharge strip and therefore the strip is significantly easier to open than the prior art strips. The strip V, at the end of the prior art, should act as both a pressure-relief strip and an air opening, and therefore the strip must either be large enough and / or raised to such an extent that it is permanently open enough to perform the latter function. It is clear that if the strip is small, it must be further raised to make it open, and if the strip is too small, insufficient metal is available to lift it sufficiently. However, since the strip in the present invention acts only as a pressure reliever, it is not necessary or desirable to raise it sufficiently to be pressed into a position where it releases air into the can during pouring, as this is provided in the second and third embodiments with the pouring strip open. It should be noted, however, that the pressure relief strip need not be less than the strip V in order to achieve the advantages of the invention.

The shape of the openings shown in Figures 3, 6, 7 and 14 is not essential and can be changed without interfering with the operation of the closure described above. It is considered probable that the pear-second opening 21 may be slightly outwardly bent, making the opening more pleasing. Similarly, the pressure relief strip 28 may be used in place of the strip 11 shown in Figure 2 or may be placed in any suitable other shaped closure.

Although all of the above embodiments comprise fully cut strips, the invention is equally applicable to closures defined by score lines or other weaknesses, as disclosed in U.S. Patent 3,334,775. The closures of this invention may be used at the ends of the can or other parts of the container and may be made of any suitable sheet metal material, such as aluminum and steel, and may be of any suitable shape, depending on the shape of the can to which the can end or other part of the container is to be attached. It is also assumed that the closures can be made of plastic using a suitable molding technique.

20 68580

The absolute size of the spout closure is not important, although normally the spout closure is sized such that the user's finger does not fully enter, but is still large enough for the liquid content of the tank to flow. Similarly, the absolute size of the orifice of the pressure vent is not critical, but normally the orifice is such that the user's finger cannot enter large enough to release the internal pressure of the reservoir when releasing pressure and sufficient air to flow in during ventilation. The seal used in fully cut closures can be any means or material, such as a sealant blend, plastic tape, adhesive film, hot melt material, a combination thereof, etc. A particularly suitable sealant blend is plastisol polyvinyl chloride in combination with a normal plasticizer and blenders. Such a plastisol should be heat-drying and form a non-sticky, somewhat flexible solid that helps hold the closure in place and maintains the hermetic joint under the pressures normally found in cans of carbonated or malt beverages.

The seal should be fragile enough to break the finger push applied to the corresponding closure. The maximum angular movements of the above closure apply only to the said aluminum grade, and to its said thickness. Changes in these and other variables in the shutter structure change the angle of maximum allowable movement.

Claims (14)

21 68580 A pressurized closure (10) for a pressure-releasing container for pressurized fluid, comprising a closure portion (11) integrally formed in the container portion and delimited by at least one weakened line, dimensioned so that it can be opened by a pressure-pushing force, the closure portion having an actuating part (12) to which the pushing force is adapted to be applied during use, and a connection point (13) associated with the container, around which said closing part is adapted to pivot during the opening step, characterized in that the closing part (11), connecting point (13) and / or the portion of the container surrounding the closure member (11) is adapted to provide means for substantially preventing permanent opening of the closure member (11) by a finger-induced pushing force, the closure member (11) being adapted to substantially return to its closed position when the finger-induced pushing force is removed. Closure according to Claim 1, characterized in that the connection point (13) of the closure part (11) is dimensioned so that when pressed by finger force the closure part cannot bend beyond the angle at which the yield point of the metal forming the connection point (13) is exceeded. Closure according to Claim 1, characterized in that the operating part (12) is raised relative to the surrounding container part, the amount of lifting of the operating part (12) and / or the size of the operating part (12) available for finger-pushing being selected so that under normal conditions the force provided by the finger cannot bend said closure around the joint (13) beyond the yield point of the metal forming said joint, whereby the opening force does not open the closure permanently. A closure according to claim 2 or 3, characterized in that the operating part (12) and the connecting point (13) are spaced apart from each other to prevent a deflection greater than said angle. A closure according to claim 3, characterized in that the container part is made such that the pouring closure (20) is defined by at least one line of weakness (21), the pouring closure (20) having a narrow and wide end which closure part (24) is made as part of a tipping closure (20) and is located at its narrow end, the connection point (13) of which is formed by a narrow metal neck (27) between two lines (25,26), the lines being at least weakened so as to be separated by said pushing force and passing towards each other from opposite edges of the tipping closure part (20). A closure according to claim 5, characterized in that the spout closure (20) is completely separated from the container, except for a metal neck (22) which acts as a spout closure hinge during this opening step, said two lines (25,26) being separator lines (20). Closure according to claim 6, characterized in that the pouring closure part (20) overlaps the surrounding parts of said container part, the metal separation lines (25,26) being substantially at the same height on each side. A closure according to claim 7, characterized in that the part of the container is the end of the can, the narrow end of the closure part (20) being made close to the center of the end. A closure according to claim 3, characterized in that the part of the container is made such that at least the line of weakness defines a pouring closure part (20 '), the pouring closure (20') having a narrow and wide end, said pressure-releasing closure part (28 ') is made part of the spout closure part (20 ') and is located at its narrower end, said connection (13) being formed by narrow metal necks (27', 27 ') inside opposite edges of the spout closure as an extension of a line (25') at least weakened, that said pushing force separates, in principle, a line running in the transverse direction of the spout closure (20 '). Shutter according to Claim 9, characterized in that the line (25 ') is a separating line made in the shutter (20'). Closure according to claim 4, characterized in that the spill closure part (31) is made in said container part, and that the pressure release closure part (34) is formed as a fixed extension of the spill closure part (31), the pressure release closure part (34) being out of its closing position. is open, it forms an air hole for the pouring step. A closure according to claim 11, characterized in that said pouring closure part is completely separated from said 23 68580 container part, except for a metal neck (32) which acts as a hinge of the pouring closure during this opening step. A closure according to claim 4, characterized in that the pressure-releasing closure part (55, 55 *) is completely separated from said container part, the operating part (56) being a long, narrow part extending at one end to the connection point (57), and each operating part (56) is overlapping under the surrounding parts of the tank part. Closure according to Claim 13, characterized in that the pressure-releasing closure part (55.55 *) is at least substantially made of a larger closure (50.50 ') which can act as a tipping closure. 68580 24