Patent Application
20120181205
The present invention refers to a container, for example, a pail or other similar container, constructed in metal sheet and of the type which comprises a tubular body with a circular or polygonal cross-section, formed by a peripheral side wall presenting a lower end edge, to which a bottom wall is affixed, and an upper end edge which surrounds an opening on which is seated and affixed, after the filling of the product to be packaged, an upper wall which can take the form of a lid to be submitted to one or more closing and opening operations.
There are well known from the prior art different constructions for containers in metal sheet, presenting the contour of the upper end edge larger than the contour of the lower end edge, with the peripheral side wall presenting an inverted frusto-conical or frusto-pyramidal shape, which progressively develops along at least most of the height of said wall. An example of this type of construction can be seen in Brazilian Patent Application PI 0804305-1 of the present applicant.
In the constructive solution described and illustrated in said prior patent application, the tubular body of the container in the form of a pail presents a certain inverted conicity for allowing the partial telescopic fitting of the tubular bodies, when said bodies are stacked still superiorly opened. This constructive arrangement allows a substantial volumetric gain in storage and transport of the tubular bodies of said containers when they are still superiorly opened.
However, in these constructions of inverted frusto-conical tubular body, the latter has the larger base of the frusto-conical shape situated in a plane axially spaced back in relation to the plane of the upper end edge of the peripheral side wall and in which plane axially spaced back the side wall is deformed to define an outer circumferential projection, which is seated on the upper end edge of the tubular body of a lower container, upon telescopically stacking said tubular bodies.
Although the construction of the type mentioned above allows obtaining a substantial volumetric gain in storage and transport of the tubular bodies which are superiorly opened and telescopically fitted one inside the other in a stack, it presents constructive limitations and functional inconveniences.
In constructive terms, these containers has the degree of mutual fitting of their tubular bodies limited by the conicity admissible in the progressive deformation of the metal sheet, which deformation is required throughout the height of the frusto-conical shape.
Besides requiring complex operations for expanding the metal sheet for obtaining the conical shape, this known constructive solution limits the versatility of the conical shapes and requires narrow tolerances in order to maintain an acceptable degree of product loss in the manufacturing line.
In these frusto-conical peripheral side walls, it is not easy to provide circumferential friezes or ribs capable of increasing the strength of the metal sheet against radial deformations of the tubular body of the container, whereby the degree of expansion of the metal sheet, as a function of the desired conicity, is also a function of the minimum structural strength required for the peripheral side wall of the container. Thus, this known constructive solution presents a limited degree of telescopic fitting, not only due to the complexity of forming the tubular body, but also due to the minimum thickness admitted for the metal sheet, impairing or even impeding the obtention of material gains. Further in relation to the known constructions of inverted frusto-conical body, it can be mentioned that each upper tubular body, in a telescopic stacking, has only its outer circumferential projection seated on the upper end edge of the lower tubular body. The upper tubular body portion, which is telescopically fitted in the interior of the lower tubular body, is not axially or radially seated against any “cradle” provided in the interior of the lower tubular body. Thus, during the handling and transport of the tubular bodies which are telescopically fitted one inside the other, an undue contact occurs between the peripheral side walls of the mutually fitted tubular bodies, which can cause damages to the external lithography and to the internal lining of said tubular bodies.
Due to the drawbacks mentioned above, it is an object of the present invention to provide a tubular body for a container of the type discussed above and which presents a relatively simple construction, allowing obtaining different telescopic fitting degrees between the superiorly opened tubular bodies with economy of metal sheet material, without relevantly fragilizing the structure of the tubular body and minimizing the risks of damages to the external and internal finishings of the tubular bodies upon handling and shipping them in the telescopic stacking condition.
According to the invention, the peripheral side wall of the tubular body of the container presents, axially spaced apart, at least two inverted frusto-conical portions of short height, defining respective circumferential reductions in the contour of the tubular body, which are dimensioned and positioned so that, upon fitting one tubular body inside the other:
the lower end edge of the peripheral side wall of the upper tubular body is seated on the lower frusto-conical portion of the lower tubular body;
a lower frusto-conical portion of the upper tubular body is seated on another frusto-conical portion of the lower tubular body, different from the lower frusto-conical portion of the latter; and
an upper frusto-conical portion of the upper tubular body is seated on the upper end edge of the lower tubular body.
In a constructive form, in which the peripheral side wall is provided with only two inverted frusto-conical portions, the lower frusto-conical portion of the upper tubular body is seated on an upper frusto-conical portion of the lower tubular body.
In another constructive form, the peripheral side wall further presents at least one inverted median frusto-conical portion, with short height, axially spaced from the upper and lower frusto-conical portions, defining a respective circumferential reduction in the contour of the tubular body, which median frusto-conical portion is dimensioned and positioned so that, upon fitting one tubular body inside the other:
the lower frusto-conical portion of the upper tubular body is seated on the median frusto-conical portion of the lower tubular body; and
the median frusto-conical portion of the upper tubular body is seated on the upper frusto-conical portion of the lower tubular body.
According to the invention defined above, the tubular bodies, which are generally in the form of pails in metal sheet, can present an easily obtainable shape which can simultaneously provide a fitting of about ¾ of the height, or even more, of one tubular body inside the other, without submitting the peripheral side wall to a contact which can destroy the finishing of the peripheral side wall of the adjacent tubular bodies, and allowing the expansion of the contour of the tubular body to progressively occur towards the upper end edge of the peripheral side wall, making the reduction of the metal sheet thickness to occur upwardly in parts presenting a constant contour and spaced from each other by the frusto-conical portions which define regions of radial strengthening of the peripheral side wall, as well as seating cradles between the mutually fitted tubular bodies.
Other advantageous aspects of the invention will become apparent with the following description.
The invention will be described below, with reference to the enclosed drawings, given by way of example of a possible embodiment of the invention and in which:
As already mentioned, the present container is of the type which comprises a tubular body C, formed in metal sheet, usually tinplate, and presenting a peripheral side wall 10 with any circular or polygonal cross-section, but usually circular and having a lower end edge 11, to which a bottom wall 20 is affixed, for example by double-seaming, and an upper end edge 12 surrounding an opening A and which is conformed to receive and retain an upper wall which, in the illustrated example, takes the form of an also metallic lid T to be removably fitted and retained on said opening A. In the illustrated construction, the container in metal sheet presents the upper end edge 12 of the peripheral side wall 10 which is outwardly bent so as to define a finishing bead 13. The finishing bead 13 is obtained by outwardly, downwardly and inwardly bending the upper end edge 12, so as to present a tubular or semi-tubular cross-section. Nevertheless, the finishing bead 13 may present different cross-sections, provided that it defines an outer peripheral step in the region of the upper end edge 12 of the peripheral side wall 10.
The lid T may be constructed of different manners, as long as it can be applied and hermetically retained against the upper end edge 12 of the peripheral side wall 10, by the filler, after filling the product in the interior of the container.
According to the invention, the peripheral side wall 10 presents two or more frusto-conical portions axially spaced apart to define respective circumferential reductions in the contour of the tubular body C.
In the illustrated construction, the peripheral side wall 10 is provided with a lower frusto-conical portion 14, a median frusto-conical portion 15 and an upper frusto-conical portion 16, which are axially spaced from each other and in relation to the lower end edge 11 and upper end edge 12 of the peripheral side wall 10, by approximately equal distances. However, it should be understood that these distances need not be the same and they can vary as a function of the desired structural strength for the different tubular portions 17 of the peripheral side wall 10, which are defined between the frusto-conical portions 14, 15, 16 and between the lower frusto-conical portion 14 and upper frusto-conical portion 16 and the respective lower end edge 11 and upper end edge 12 of the peripheral side wall 10.
It should be further understood that the peripheral side wall 10 can be provided with only one lower frusto-conical portion 14 and one upper frusto-conical portion 16, without the provision of any median frusto-conical portion 15.
The lower frusto-conical portion 14, upper frusto-conical portion 16 and median frusto-conical portion 15, the latter being provided in a number ranging from “zero” to an integer generally not superior to “three”, present a height H and a radial width R with reduced dimensions and are designed to allow obtaining a circumferential contour reduction sufficient to allow: providing the loose telescopic fitting between the containers; forming a circumferential step which defines a “cradle” for mutually seating the tubular bodies C of two containers; and defining a “frieze” (portion of the frusto-conical wall) to increase the structural strength of the peripheral side wall 10 in the radial direction.
Generally, the dimensioning of the frusto-conical portions 14, 15, 16 is made so that the inclined wall portion presents an angle not higher than 45° in relation to the plane which contains the axis of the container, so that the structural strength of the tubular body C in relation to the axial compression is not unacceptably impaired.
This construction allows the largest expansion of the metal sheet to be progressively and upwardly applied to the different tubular portions 17 of the peripheral side wall 10, allowing the thinner walls to be defined in the upper tubular portions 17 which are subject to a smaller pressure of the product to be filled and which are radially reinforced by the nearest frusto-conical portions.
Thus, the tubular body C can be formed from a metal sheet with a smaller thickness, without the container having its peripheral side wall structure inadequately weakened.
According to the proposed construction, the tubular portions 17 of the peripheral side wall 10 present a constant circular or polygonal cross-section throughout the height thereof, maintaining a radial spacing or gap in relation to the adjacent wall tubular portions of other tubular body C, in telescopic stacking, corresponding to the radial width R of the frusto-conical portions 14, 15, 16 associated with the different tubular portions 17.
As illustrated, upon fitting a tubular body C in the interior of other tubular portion C, the lower end edge 11 of the peripheral side wall 10 of the upper tubular body C is seated on the lower frusto-conical portion 14 of the lower tubular body C and the upper frusto-conical portion 16 of the upper tubular body C is seated on the upper end edge 12 of the lower tubular body C, independently of being or not provided one or more median frusto-conical portions 15.
When no median frusto-conical portions 15 are provided, the lower frusto-conical portion 14 of the upper tubular body C is seated on the upper frusto-conical portion 16 of the lower tubular body C.
In case at least one frusto-conical portion 15 is provided, the lower frusto-conical portion 14 of the upper tubular body C is seated on the median frusto-conical portion 15 of the lower tubular body C and the median frusto-conical portion 15 of the upper tubular body C is seated on the upper frusto-conical portion 16 of the lower tubular body C.
This constructive arrangement allows the frusto-conical portions 14, 15, 16 of a tubular body C to operate as circumferential steps or “cradles” for the seating of the lower end edge 11 and of the lower frusto-conical portion 14 and median frusto-conical portion 15 of other tubular body C fitted inside the lower one, guaranteeing high stability and high interpenetration fitting, without occurring frictional contact between the tubular portions of the peripheral side wall 10 of each two tubular bodies C fitted one inside the other.
While only one constructive embodiment for the container has been illustrated herein, it should be understood that the latter may present different embodiments contained within the constructive-functional concept defined in the claims that accompany the present specification.
| Number | Date | Country | Kind |
|---|---|---|---|
| PI-0902427-1 | Jul 2009 | BR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/BR2010/000258 | 7/26/2010 | WO | 00 | 3/26/2012 |
