WO2015089612A1

WO2015089612A1 - Structural improvement in metal cans

Info

Publication number: WO2015089612A1
Application number: PCT/BR2014/050036
Authority: WO
Inventors: Antonio Carlos Teixeira ÁLVARES; Antonio Roberto Sene
Original assignee: Brasilata S/A Embalagens Metálicas
Priority date: 2013-12-17
Filing date: 2014-12-10
Publication date: 2015-06-25
Also published as: AR101234A1; BR102013032431A2

Abstract

The improvement is directed to metal cans with a tubular body (10) comprising a lateral wall (11) onto which is double seamed an outer peripheral edge (13) of an annular upper wall (12) which incorporates an upper annular projection (16) and a pending skirt (15) defining an opening (A) and a seat for seating a removable lid (20). A region (R) of the annular upper wall (12), radially external to the upper annular projection (16), incorporates at least one circumferential rib (18), in high relief, formed by plastically deformed material of said region (R) of the annular upper wall (12) and defining, in relation to the plane of said region (R), an axial projection corresponding to a fraction of the axial projection defined by the upper annular projection (16) in relation to the same region (R).

Description

"STRUCTURAL IMPROVEMENT IN METAL CANS"

Field of the Invention

The invention refers in general to a structural improvement applied in metal cans of the type defined by a tubular body having a generally cylindrical lateral wall, of constant or variable diameter, interiorly closed by a bottom wall and carrying an annular upper wall having an outer peripheral edge which is double seamed to an upper edge of the tubular body, and an inner edge defining an upper opening for access to the interior of the can, and which is configured to form a closing seat in which is seated and axially removably retained a lid formed in plastic, metal or any other material compatible with the product to be stored in the container. In a particular manner, the invention refers to an improvement introduced in the construction of the annular upper wall of the can, to increase the structural resistance of said annular upper wall.

Prior Art

There are well known in the art the metal cans presenting an annular upper wall defining a structural ring double seamed to the upper edge of the tubular body of the can, more specifically in the upper edge of the lateral wall thereof .

The annular upper wall is disposed in a generally orthogonal manner to the axis of the can and incorporates, in its median portion, an upper annular projection, obtained by bending the metallic sheet and presenting, for example, a profile in the approximate form of an inverted "U", with rounded edges and projecting upward from the average plane of the upper wall .

The provision of the upper annular projection allows obtaining a greater stiffening of the annular upper wall, thus allowing for a reduction in the thickness of the sheet used for forming said upper wall, and consequently reducing the material consumption. In the illustrated construction, the inner peripheral edge of the upper wall incorporates, in a single piece, a pending skirt whose lower end is radially curved inwards, upwards and outwards, until reaching an adjacent portion of the inner surface of the pending skirt, in order to define a tubular circumferential rib having a generally circular or substantially circular cross section.

The pending skirt defines an opening for access to the interior of the can and also a seat, generally cylindrical, in which is press-fitted the peripheral wall of a manually removable closing lid, which may be closed during the period of progressive consumption of the contents of the can.

Constructions of annular upper walls of the type defined above may be seen, for example, in the prior patent documents PI9408643-5, PI9702736-7 and PI9804178-9.

The provision of the upper annular projection in the annular upper wall, as proposed in the documents mentioned above, actually leads to a greater structural resistance of said upper wall.

However, even with the incorporation of the upper annular projection in the annular upper wall of the can, the structural resistance required for an adequate and secure operational behavior of the can still requires a minimum sheet thickness for forming the structural upper wall.

Despite the increase in the structural resistance of the upper wall of the can, these prior constructions do not allow that said increase in the resistance reaches the entire radial extension of the annular upper wall.

One fact is that the annular region of the annular upper wall radially external to the upper annular projection is subjected to major bending stresses when closing forces are applied onto the lid. Thus, even with the increase in the structural resistance provided by the upper annular projection, the upper wall still requires a certain minimum sheet thickness in order not to undergo permanent plastic deformations upon the opening and closing operations of the lid.

Summary of the Invention

As a result of the description above in relation to the prior art, the present invention has as one of its objectives to provide a structural improvement in the construction of the annular upper wall of metal cans of the type mentioned above, providing an even higher structural resistance, thus allowing it to be constructed from a metallic sheet with reduced thickness, thinner than the thinnest one presently used for this type of upper wall, without said thickness reduction reducing the structural resistance of the upper wall to values lower than those expected or desired in such a way that said upper wall does not undergo unacceptable plastic deformations during the opening and closing operations of the lid.

These and other objectives of the present invention are achieved with a metal can of the type presenting a tubular body comprising a lateral wall, in whose upper edge is double seamed an outer peripheral edge of an annular upper wall which incorporates, medianly and in a single piece, an upper annular projection and, in an inner peripheral edge, a pending skirt defining an access opening to the interior of the can and a seat for seating a removable lid.

According to the invention, a region of the annular upper wall of the can, radially external to the upper annular projection, incorporates, in its median portion and in a single piece, at least one circumferential rib, in high relief, formed by plastically deformed material of said region of the annular upper wall and defining, in relation to the plane of said region, an axial projection corresponding to a fraction of the axial projection defined by the upper annular projection in relation to the same region.

In a preferred constructive form, the circumferential rib is continuous and presents a V shaped cross section, with the vertex thereof being sharply rounded and having the ends of the lateral legs incorporated to adjacent opposite regions of said annular upper wall region of the can .

With the construction generally defined above, besides the annular upper wall of the can being provided with the upper annular projection, it now incorporates the circumferential rib, which defines an additional structural element incorporated to a region of the annular upper wall subjected to major stresses during the closing and opening operations of the lid.

The provision of the circumferential rib in said region of the annular upper wall, in addition to the provision of the annular projection, imparts to the annular upper wall a considerably higher structural resistance in relation to that obtained with the previous constructions, allowing to obtain an upper wall having adequate structural resistance and which is formed in a metallic sheet with reduced thickness, that is, with less material consumption.

Brief Description of the Drawings

The invention will be described below with reference to the attached drawings, given by way of example of a possible construction for the upper wall of the can. In the drawings:

Figure 1 represents a partial diametrical sectional view of the upper region of a can provided with an annular upper wall built according to the prior art and in whose opening for access to the interior of the can is fitted a removable lid, also of known construction; and

Figure 2 represents a partial diametrical sectional view of the upper region of a can provided with an annular upper wall built according to the present invention and in whose opening for access to the interior of the can is fitted a removable lid of particular construction.

Description of the Invention

As illustrated in the attached drawings, the present improvement is applied to a metal can defined by a tubular body 10 having a lateral wall 11, generally cylindrical and with a constant or variable diameter, which is interiorly closed by a bottom wall (not illustrated) and carrying an annular upper wall 12, having an outer peripheral edge 13 double seamed to an upper edge of the lateral wall 11 of the tubular body 10 and an inner peripheral edge 14 incorporating a pending skirt 15 which defines an opening A for access to the interior of the can and which is configured to form a seat for seating a removable lid 20, formed in plastic, metal or any other material compatible with the product to be stored in the container. The annular upper wall 12 incorporates, in its median region and in a single piece, an upper annular projection 16, which may simultaneously operate as a structural element and as an element for making evident the first opening of the lid 20.

In the exemplary construction of the drawings and which is object of patent BR-PI9408643-5 of the applicant of the present patent application, the pending skirt 15 is provided with a lower end portion curved inwards the opening A, upwards and against the pending skirt 15, in order to form a continuous tubular rib 17 which presents a generally circular form, as described in said prior patent.

However, it should be observed that the construction of the pending skirt 15 may present different arrangements, without these constructive modifications altering the constructive or functional aspects of the present invention.

According to the invention, a region R of the annular upper wall 12 of the can, radially external to the upper annular projection 16, incorporates in the median portion thereof and in a single piece, at least one circumferential rib 18, in high relief, formed by the plastically deformed material of said region R of the annular upper wall 12 and defining, in relation to the plane of said region R, an axial projection corresponding to a fraction of the axial projection defined by the upper annular projection 16 in relation to the same region R.

The circumferential rib 18 has the material for its formation defined exclusively by the plastically deformed material of the adjacent opposite portions of said region R of the annular upper wall 12 of the can, which allows maintaining the same blank plate diameter used in conventional constructions.

According to the illustrated construction, the circumferential rib 18 is continuous and presents a cross section in the form of V, with a sharply rounded vertex, or in the form of a U having rounded vertexes, the ends of the lateral legs of the circumferential rib 18 being incorporated to adjacent opposite regions of the region R of the annular upper wall 12 of the can. Preferably, the circumferential rib 18 has the cross section thereof in the form of V or inverted U, with the vertex in the form of V or the bottom in the form of U facing the exterior of the can.

Still according to the illustrated construction, the region R of the annular upper wall 12 of the can incorporates a single circumferential rib 18, located in the median portion of said region R.

The provision of a single circumferential rib 18 is usually the solution of choice, due to the fact that said region R of the annular upper wall 12 usually presents a radial extension capable of allowing the provision of a single circumferential rib 18 which, in function of said reduced radial dimension of region R, is sufficient to provide the desired structural result which allows a further reduction in the metallic sheet thickness.

The axial projection of the circumferential rib 18 should be only sufficient to provide said desired effect of increasing the structural resistance of the annular upper wall 12, having preferably a value equal to the thickness of the metallic sheet used for forming the annular upper wall 12, in order that the material for the formation thereof results exclusively from the plastically deformed material, during the stamping operation of the region R of the annular upper wall 12.

With the construction proposed by the invention, besides the annular projection 16, the region R of the annular upper wall 12 now incorporates the circumferential rib 18, which defines an additional structural element incorporated to a region of the annular upper wall 12 subjected to major stresses during the closing and opening operations of the lid 20.

The provision of the circumferential rib 18 imparts to the annular upper wall 12 a considerably increased structural resistance, allowing obtaining an upper wall with adequate structural resistance while formed in a metallic sheet of lower thickness, that is, with smaller material consumption. For example, in the known 1 gallon cans, the reduction in the thickness of the metallic sheet can be higher than 10%.

As illustrated in the drawings, the lid 20 may be formed in a single piece of metallic sheet, comprising a bottom wall 21, usually in the form of a flat disc which incorporates, superiorly and peripherally, a lateral wall 22 provided with a free upper edge 22a to be seated and axially retained inside the seat defined by the pending skirt 15 of the annular upper wall 12.

In the exemplary construction illustrated in the drawings, the lid 20 has the lateral wall 22 thereof provided with a continuous peripheral recess 22b, inside which is tightly fitted and axially retained the continuous tubular rib 17 of the pending skirt 15.

In the illustrated construction, both the continuous tubular rib 17 of the pending skirt 15 and the continuous peripheral recess 22b of the lateral wall 22 of the lid 20 present a contour at least partially circular and complementary, in order that the mutual seating of said parts promotes not only the axial retention of the lid 20 in the opening A of the can 10, but also a sealing effect in this frictional seating region. However, it should be understood that the continuous tubular rib 17 and the continuous peripheral recess 22b may present configurations other than the circular tubular one illustrated in the drawings.

The lid 20 may have the free upper edge 22a thereof curved outwards, downwards and against the lateral wall 22, in order to define a tubular upper rib 22c to be seated onto the annular upper wall 12 of the can 10, in the region surrounding the opening A.

The lid 20 may have the bottom wall 21 comprising a peripheral annular portion 23 adjacent to the lateral wall 22, a median portion 24 and an annular rib portion 25 presenting a cross section in the approximate form of an inverted "U", having the lateral legs thereof interiorly and respectively incorporated to adjacent edges of the peripheral annular portion 23 and median portion24 of the bottom wall 21.

The annular rib portion 25 may project upward from the annular peripheral portion 23 and median portion 24 of the bottom wall 21, remaining spaced from the lateral wall 22 by a distance which, due to the thickness of the metallic sheet, provides to the marginal region of the lid 20 the necessary structural stiffness to resist the compression forces to be applied on the lid 20, upon fitting the latter into the opening A of the can 10.

Still according to the illustrated configuration, the median portion 24 of the bottom wall 21 is located in a plane higher in relation to a plane which contains the peripheral annular portion 23 of said bottom wall 21, as described in document PI 0405458-0.

As described in the prior patent application BR 10 2013 003708 7, of the same applicant, the peripheral annular portion 23 of the bottom wall 21 incorporates, in a single piece, at least one circumferential rib 26, in high relief, preferably continuous and with a cross section in the approximate form of an inverted U or V, with rounded ends, formed by deforming the metallic sheet itself, that is, by the plastically deformed material of the peripheral annular portion 23, without the need for increasing the blank diameter in order to be possible to obtain the circumferential rib.

While only one constructive form of the present improvement has been illustrated herein, it should be understood that several changes can be made in the form of the components parts, without departing from the constructive concept defined in the claims that accompany the present disclosure.

Claims

1. A structural improvement in metal cans, of the type presenting a tubular body (10) comprising a lateral wall (11) in whose upper edge is double seamed an outer peripheral edge (13) of an annular upper wall (12) which incorporates, in the median portion thereof and in a single piece, an upper annular projection (16) and, in an inner peripheral edge (14) thereof, a pending skirt (15) defining an opening (A) for access to the interior of the can and a seat for seating a removable lid (20) , character! zed in that a region (R) of the annular upper wall (12) of the can, radially external to the upper annular projection (16), incorporates, in the median portion thereof and in a single piece, at least one circumferential rib (18), in high relief, formed by plastically deformed material of said region (R) of the annular upper wall (12) and defining, in relation to the plane of said region (R) , an axial projection corresponding to a fraction of the axial projection defined by the upper annular projection (16) in relation to the same region (R) .

2. The improvement, as set forth in claim 1, characteri zed in that the circumferential rib (18) is continuous and presents a V shaped cross section, with the vertex thereof being sharply rounded and with the ends of the lateral legs thereof being incorporated to adjacent opposite regions of the region (R) of the annular upper wall (12) of the can.

3. The improvement, as set forth in claim 2, characteri zed in that the circumferential rib (18) has a cross section in the form of an inverted V, with the vertex of the latter facing the exterior of the can.

4. The improvement, as set forth in claim 1, characterized in that the circumferential rib (18) is continuous and presents a U shaped cross section, with rounded vertexes and with the ends of the lateral legs thereof being incorporated to adjacent opposite regions of the region (R) of the annular upper wall (12) of the can .

5. The improvement, as set forth in claim 4, character! zed in that the circumferential rib (18) has a cross section in the form of an inverted U, with the bottom of the latter facing the exterior of the can.

6. The improvement, as set forth in any of claims 1 or 5, character! zed in that the region (R) of the annular upper wall (12) of the can incorporates a single circumferential rib (18) located in the median portion of said region (R) .

7. The improvement, as set forth in any of the claims 1 to 6, character! zed in that the circumferential rib (18) has the material for its formation exclusively defined by the plastically deformed material of the region (R) of the annular upper wall (12) of the can.