IMPROVED ENTRY OPENING FOR METAL CONTAINERS

Abstract: Improved entry opening for metal containers, characterized in that the lateral wall of the container (1) presents adjacent to its upper edge a widened-out portion (2) which folds up upon itself giving rise to a rim (3) of round cross-section, which extends inwardly and down­ warly in order to converge to a virtual parallel line coinciding with the starting point of the widened-out outside, in which area the so obtained flange (4) changes its direction according to a V-shaped ascending folding (5) which is substantially coplanar with the internal surface of the container wall, forming at its upper part another out­ wardly curved folding-up (5) which is tangent, concentric and stepped with respect to the above-mentioned rim (3).

Description: This invention relates to a rim structure for a metal container assembly according to claim 1. More particularly, this invention provides an improved opening edge which is specially adapted for cylindrical metal containers provided for containing paints, enamels and any liquid products having a varying density and requiring a tight-closed cover plate for its preservation. This entry opening according to the invention has unique characteristics which render it advantageously useful with respect to presently commercially known embodiments for similar uses, by incorporating precise conditions by means of which its manufacture costs can be reduced since its manufacture is wholly mechanical, being made by means of only one folding operation of the opening edge of the container in order to obtain concentric and substantially stepped rims, the whole being obtained from only one sheet, contrary to the conventional system in which a complex and expensive process is required in order to obtain identical results. A rim structure as above stated is already known (see US-A-2,084,084). This, however, does not provide an optimum entry opening with the desired hight-closing of the cover plate. As a matter of fact, the present technique first requires to shape the edge of the container so as to obtain a substantial widening-out of its opening mouth, to manufacture a metal hoop or ring of a special cross-section, and finally to carry out joining of both elements by means of a mechanical process. From the preceding, the important cost increase which is entailed by a conventional entry opening with respect to an entry opening according to the invention is obvious, the opening of the invention being obtained by means of a sole operation which results in an edge which forms an optimum entry opening able to receive the cover plate which ensures the tight closing. In order to solve the above mentioned problems, the invention provides a rim structure as above stated and having the features indicated in the characterizing portion of claim 1. Other embodiments of the present invention result from claims 2 to 4. In order that this invention is better understood, an embodiment thereof is hereinafter described by way of an example only, with reference to the non-limitative enclosed drawing. The sole Figure shows a cross-section of the entry opening of the container 1 which comprises adjacent to its upper edge a divergent or widened-out portion 2 which folds up upon itself giving rise to a rim 3 of round cross-section, which extends inwardly and downwardly as a flange 4. The latter converges to a virtual parallel line coinciding with the starting point of the widened-out outside, in which area this flange changes its direction in order to form another upward and vertical flange 5 which presents in its upper portion another outwardly curved folding-up, so forming a second rim 6. Both rims 3 and 6 which are concentric and stepped provide an optimum seat for the cover plate, so as to obtain the desired tight closing.

Claims: 1. A rim structure for a metal container having a cylindrical sidewall, comprising an annular wall part (2) integrally joined to and projecting radially outwardly and axially upwardly from an upper edge of the cylindrical sidewall, said annular wall part (2) being integrally folded over on itself at an upper edge thereof to form a rounded annular outer top flange (3), an inclined annular flange (4) being integrally joined to and extending radially inwardly and axially downwardly from said outer top flange (3), said inclined annular flange (4) at a location remote from said outer top flange (3) being integrally folded inwardly and upwardly onto itself to define a generally V-shaped fold formed by said inclined annular flange (4) and an axially upstanding annular flange (5) which defines an opening for the metal container (1), said upstanding flange (5) having an integral free edge part remote from said fold, said free edge part being folded radially over against said upstanding flange (5) to form a rounded annular inner top flange (6), characterized in that said outer wall part (2) is straight as it diverges radially outwardly and said inclined annular flange (4) is straight as it inclines downwardly so as to terminate at a lower end disposed against the outer wall part (2) in the vicinity of where the latter diverges from the cylindrical sidewall, said upstanding flange (5) defines an inner annular surface having a diameter which is equal to or only slightly smaller than the inner diameter of the cylindrical sidewall, and said upstanding flange (5) is folded radially outwardly over onto itself to define said annular inner top flange (6) which is spaced axially downwardly a small extend from said outer top flange ( 3). 2. Rim according to claim 1, wherein said rounded inner top flange (6) is formed at a tangent to said inclined flange (4), preferably midway between said fold and said outer top flange (3). 3. Rim opening according to anyone of claims 1 and 2, wherein said rounded annular inner top flange (6) terminates in a free edge part which abuts an outer surface of said upstanding flange (5). 4. Rim opening according to anyone of claims 1 to 3, wherein the upstanding flange is coaxially aligned with the cylindrical sidewall.

Inventors: HIELGA BRAVO, RAFAEL
Applicants: PURIFICATION ALVAREZ SANCHEZ
Application year: 1988
Main classification: B65D1
IPC codes: B65D1