Can with metal lid for vacuum-sealing of foodstuff preserves

Abstract: A can that is formed by an overall cylindrical body (1) with nailed bottom wall (2) and presenting on its superior part and close to the aperture a roundish fillet (3), outwardly turned to permit the application of an easy-opening lid, formed essentially by a circular panel (4), with short border or descendent skirt (5), provided by a snarrow peripheric fillet (10), such a lid presenting a sealing gasket (6) on its internal surface and presenting a circular basin-shaped depression (7), with a cental hollow (8) for a detachable seal (9), so that, in accordance to the present improvements, is given a new disposition in the superior part of the can body, by which the referred border or skirt (5) of the lid and its respective peripheric fillet (10) are presented re-entrants and secluded in relation to the side wall fo the cylindrical body (11) of the can.

Description: The present invention relates to some improvements introduced in vacuum-closure cans by non-nailed, easy-opening, metallic lids, for foodstuff packing. The can for which the present improvements were realized is the object of the Brazilian patent BR No. 9203029 of July 25, 1995 of the same inventor (or FR-A-2 718 115), on its original and well-known form, comprises essentially a cylindrical body with bottom wall normally fixed by nailing, comprising in its superior part and closely to the top, a roundish fillet or curl outwardly turned that allows the can to be closed by means of a non-nailed, easy-opening metallic lid. The preamble of claim 1 is based on this prior art. The referred lid is the object of the Brazilian patent No. 9103906-0, of February 01, 1994 of the same inventor and such a lid essentially comprises a circular panel, presenting descendant edge or casing, provided with snarrow peripheric fillet; such a lid being provided with blocking gasket and, on the nucleous of its panel, with a circular depression with a central hollow, which is sealed by means of a resinous dettachable seal. It is important to notice that the idealization of the present invention could not be feasable unless the previous concretization of an easy-opening lid, which has been successfully adopted in the closure of glass-made cups and pots. This allowed, by means of an innovative device introduced in such a can, this kind of lid to be used with the same practical advantages in tinned food closure. Both easy-opening lid and can realizations, mentioned above, required great efforts and investments in research and experiments; including the creation of special equipments and new tecnologies, in order to allow the execution of this package in high production scales. This kind of easy-opening can came to advantageously modify the traditional systems of metallic foodstuff packing closure, and distinguishes from others basically by not comprising any mechanical device for lid retemption, excluding any other mean for closure, as long as the lid is kept closed only by atmospheric pressure. It performs, therefore, a physical closure which is given by elevate vacuum formed in the interior of the package. These vacuum-closure cans by non-nailed, easy-opening, metallic lids, have been advantageously distinguished from the conventional cans by their practical and utilitarian aspect, focusing not only the manufacturers of foodstuff packings but particularly the consumers; thank to the safety and simplicity that they offer against accidents - once the can is opened, it does not require any auxiliar device or effort, as long as the lid is realised by the aid of a simple extraction of the label which is lifted with the nail edge and, posteriorly removed by the usuary's fingers. Although these cans have been entirely corresponding to their purposes, some inconvenients regarding closure were shown during practice, not only on the industrial operation lines but yet on its storage, delivering and general manipulation. This is due to the fact of the closing process showing up much delicate and being obtained only by vacuum action and through the application of vapour spargers; such a tinned product being, at this time, at a temperature higher than 194° F. As long as the canned product temperature is very high, the vapour-sparger closing machine naturally forms very low vacuum in the interior of the can, providing, by this way and at this moment, very slow safety for the closure. It must be considered that such cans, while submitted to the industrial process, undergo the following serial steps: filling, vacuum-closing, sterilizing and cooling. From one step to other, the cans are transported in rows and at high velocities in order to be automatically inserted into the corresponding steps machines, provoking collisions and constrictions among such cans. During this critical process, the peripheric fillets placed on the outwardly projected salient lids, lift up one over another, promoving a bunch of accidental openings of the lids, at face of the closure fragility due to the low vacuum. As a matter of fact, many losts in the production occour, what makes impossible to the sealing machine to provide a higher vacuum while the product in the cans are at temperatures higher than 90°C (194° F). Such conditions cannot be modified during the closing process of the easy-opening cans mentioned above, as long as the vapour sparge as well as the canned product are above 90°C (194° F). This requires the cans to be istantaneously closed to keep the vapour sparge in the free space that is formed above the product, in order to be condensated and, thus, form the initial vacuum. Therefore, as can be observed, these high temperatures resulting from the closing process of this kind of package cannot be modified because, if so, as soon as the final process takes place, a high vacuum (which is responsable to the closure safety) will result from such temperatures. Another problem realized during practice for this kind of package that will be, on the same way, solved through the present improvements, consists in the fact that, whenever the closed cans - provided with high vacuum and ready for transport and storage - are closely arranged and placed on the pasteboard boxes, they keep their peripheric fillets (placed on the lids) intimately supported and submitted to lifting up among themselves. The action of the weight of the boxes piles provokes the effort of one fillet against other and the vibration during transport causes accidental opening of the cans, and, thus total loss of the product. The above mentioned problems are solved by the can and lid assembly according to claim 1. In order to definitely solve all these inconvenients, providing to this kind of easy-opening can perfect safety conditions against accidental opening, as during the production process as during the transport, storage or general manipulation, the present improvements were idealized, by which - thank to an innovative disposition introduced - it is possible to keep the peripheric fillets placed on the lids sufficiently secluded or displaced on a re-entrant manner in relation to the cylindric body whenever the cans are closed and constrictly agrouped. This allows the cans to be friction-free and eliminates the both undesirable mouting and superposition of these fillets. The present invention not only focuses a simple modification in the shape and dimensions of the can but yet afford a new disposition, able to alter the displacement of the peripheric fillet, as long as it is changed from an inappropriate and harmful position to another one that protects it from any damage on its fuctions, and eliminates the inconveniences afore mentioned, as will be widely demonstrated on this descriptive report. It must be yet observed that such a modification, which comprises the object of the present improvements, does not interfere in any other constructive conception already known in metallic cans manufacturing as long as this closing system comprises, on its original shape, a creation of the same inventor and no similar inventions can be found all over the world. At such a closing system, only physical means are used as long as mechanical devices - such as clamps, nails or screw threads - are completely useless on lid retemption while on its closing position, at the aperture of the can. The improvements introduced into vacuum-closure cans by non-nailed, easy-opening, metallic lids for foodstuff packing, are represented by the following drawings: Fig. 1 is a side view of the can, showing its improvements; such a can being closed by its respective lid; Fig. 2 is a top view of the can and its respective lid; Fig. 3 is a side view of two improved cans, leaned against each other, so the extensions between the top edges or bottom edges can be observed, as well as between the respectives peripheric fillets; Fig. 4 is a sectional side view, showing an amplified detail of the new disposition introduced in the can, providing due spacement and protection of the edges and peripheric fillets of the can against friction and supports; Fig. 5 is a side view showing, for comparison means, two cans and respective lids of the well-know type, placed leaned against each other, enabling the observation of both undesirable effects of upliftment and overlapping of the peripheric fillets placed on the edge of the lid that are responsible to the accidental release of the lids. Particularly describing such an invention and, in accordance to what was shown on the drawings that are joined to this descriptive report, such mentioned improvements provide a new disposition to the superior part of the can body which, on its original and known form, is the object of the Brazilian Patent BR No. 9203029-7, of the same inventor and comprises an overall cylindrical body (1), a nailed bottom wall (2) and, on the superior part, close to the aperture, a roundish fillet or curl (3) outwardly projected, this one being susceptible to receiving a non nailed, metallic, easy-opening lid formed by a circular panel (4), with ascendent edge (5), where, on its internal surface, is placed a seamming gasket (6) and, in the middle of the panel, a circular basin-shaped depression (7), with a central hollow (8) which is sealed by a resinous, thermo-plastic, detachable sealing-wax (9). Such lid is the object of the Brazilian Patent No. 9103896-0, of the same inventor. This kind of lid is provided, on the inferior and peripheric edge of the border or skirt (5), with a snarrow and roundish fillet (10), which is meant to facilitate the raising and withdrawal of the lid from its closing position, posteriorly to the seal extraction and release of the vacuum, this last one being responsible for the can retemption. In the already known type of these cans, whenever the lid was applied or placed in the closing position - as shown in fig. 5 - the peripheric fillets (10) were kept salients and laterally projected to outside, in relation to the cylindrical body (1) of the can, in such a way that, whenever the cans were arranged in groups, side by side, these peripheric fillets (10), were maintained strictly leaned among themselves, being submitted to mounting provoked by vibrations and tremblings, what proportinates tha accidental opening of the cans, despiting the reasons previously exposed. In accordance to the present mprovements and as shown by figs. 1,3 and 4, a new disposition was given to the superior part of the can body, by which was provided enough retraction or retirement of the edge or skirt (5) of the can and of its respective peripheric fillet (10) in relation to the lateral wall of the cylindrical body (1) of the can, enabling, therefore, that, whenever the cans are agrouped or intimally leaned against each other, these peripheric fillets (10) are kept free of support and friction and, though, uncapable of mounting or overlapping, this one being responsible to the accidental opening of this kind of packing. In other words, this kind of problem is completely avoided in force of the present improvements. It is still important to clarify, by means of a better evaluation of the importance of the present improvements, that this kind of can, of which closure is obtained by a metallic, non-nailed, easy-opening lid, being retained only by vacuum action, excepting any other mechanical mean of retemption, offers lots of advantage and deserves the preference of the consumers, thanks to the extreme easiness for opening as well as to the safety against wounds on the usuary's hands, being recognized as a great evolution in metallic packings. Nevertheless, the above mentioned problems, observed during practice, have been threatening such a preference, in order to desestimulate the continuity of its manufacturing. Such problems were totally solved and eliminated by the referred improvements, that comprise the object of the present invention. In further, we are to explain that as the vacuum-closure system by metallic, non-nailed, easy-opening lids as the lid on its original and well-known shape, hereto mentioned and presented by the drawings, do not make part of the present invention, as long as they comprise the objects of previous patents of the same inventor. By this way, only the introduced improvements are pertinent as an invention, by which the problems concerned to the accidental opening of the can were completely eliminated.

Claims: Vacuum-closure can with a metallic, non-nailed, easy-opening lid for foodstuffs packing, which comprises a can that is formed by a body having a cylindrical portion (1) with a nailed bottom wall (2), presenting on its upper part and close to the aperture , an outwardly turned curl (3) receiving the lid, which comprises a circular panel (4), a short border or descendent skirt (5) and an annular curl (10), the lid presenting on its internal surface a sealing gasket (6), and in the middle of said panel (4) a circular basin-shaped depression (7) with a central hole (8) which is sealed by a resinous, detachable seal (9), characterized by the fact that the body (1) of the can presents on its upper part, a conic portion resulting in a diametrical reduction at the opening of the can, to provide enough retraction of the skirt (5) and the curl (10) of the lid in relation to the cylindrical portion of the body when placed on the can, in such a way to avoid the leaning or the friction between fillets (10) of the lids of different cans whenever the cans are grouped and lean side by side.

Inventors: ROJEK ARNALDO, ROJEK, ARNALDO
Applicants: ROJEK METALGRAFICA, METALGRAFICA ROJEK LTDA.
Application year: 1997
Main classification: B65D51
IPC codes: B65D43, B65D81, B65D51