WO2013166573A1

WO2013166573A1 - Closure device for cans

Info

Publication number: WO2013166573A1
Application number: PCT/BR2013/000157
Authority: WO
Inventors: Antonio Carlos Teixeira ÁLVARES; Silvério Cândido DA CUNHA
Original assignee: Brasilata S/A Embalagens Metálicas
Priority date: 2012-05-08
Filing date: 2013-05-08
Publication date: 2013-11-14
Also published as: AR090962A1; BR102012010869A2; UY34787A

Abstract

The present device is applied to a can comprising: a body portion (11); a neck portion (13), incorporating an outer peripheral ridge (15) and being joined to the body portion (11) by a transition portion (14); and a lid (20) carrying an outer peripheral rib (25). A retention ring (40) is seated on the outer peripheral rib (25), surrounding the latter and being locked under the outer peripheral ridge (15). A seal strip (50), interrupted by an axial gap (FA), has an upper edge (50a) joined, by a weakened junction region (50c), to the retention ring (40). One of the ends of the seal strip (50) incorporates a first end (53a) of a circumferential projection (53) which is superiorly joined, by breakable connection means (52), to the retention ring (40) and which has a free opposite end (53b), overlapped to the other end of the seal strip (50).

Description

"CLOSURE DEVICE FOR CANS"

Field of the invention

The present invention refers to um closure device to be applied in cans formed in metallic sheet and which comprise a tubular body portion, usually of circular cross section and carrying a bottom wall, an upper neck portion having a contour smaller than that of the body portion, and a transition portion joining the body portion and the neck portion. The neck portion has an end edge defining the contour of an upper opening of the can, into which is fitted a removable lid.

Background of the Invention

There are well known from the prior art the tubular cans of metallic sheet comprising a body portion having a circular or polygonal cross section, which is inferiorly closed by _^ a bottom wall and superiorly joined, by a transition portion, to a neck portion having both its cross section and height reduced in relation to those of the body portion.

The provision of the transition portion in the upper region of the can provides a considerable increase in the structural resistance of the latter, allowing for the elimination of the upper annular portion, with the upper opening of the can corresponding to the inner cross section of the neck portion. In this construction, it is sufficient that the upper end edge of the can, that is, of the neck portion, is curved, or otherwise worked, in order to form a curl, or outer peripheral ridge, around the upper opening of the can and defining, together with the upper end edge of the latter, a seat for the seating of a removable lid, comprising a panel portion incorporating a peripheral tubular portion to be tightly fitted with interference into the upper opening, inside the neck portion, said peripheral tubular portion having a free upper edge which is curved, or otherwise worked, to form a curl or outer peripheral rib of a partially tubular shape, inferiorly open and housing an annular gasket which is seated and pressed against the outer peripheral ridge of the neck portion, upon the fitting of the peripheral tubular portion of the lid into the upper opening of the can.

This prior art construction is disclosed in documents PCT/BR2011/000166 (of the same assignee) and DE 4021211 Al.

These cans may have its closure elements further comprising a retention ring of plastic material, having an upper annular portion to be seated onto the outer peripheral rib of the lid, and a pending skirt portion, surrounding the outer peripheral rib of the lid and the outer peripheral ridge of the neck portion and incorporating an inner circumferential projection, to be seated and axially locked under the outer peripheral ridge of the neck portion, in order to retain the outer peripheral rib of the lid seated against the outer peripheral ridge of the neck portion, as described and illustrated in the aforementioned document PCT/BR2011/000166.

Although the retention ring may be constructed in order to make difficult the removal of the lid without making evident the opening of the can and access to its contents, the known constructions do not provide an effective tamper evident seal, of simple construction and which must be necessarily broken in order to allow and make evident a first opening of the can .

Still another drawback of the known solutions is related to the need of providing a stable stacking with no interlocking of the retention rings and suspension rings in the magazines for feeding said rings into equipment for mechanically assembling said retention rings and suspension rings in the peripheral rib of the lid and around the neck portion of the can, respectively.

Summary of the invention

Due to the limitations of the known solutions, it is an object of the present invention to provide a closure device, for a can of the type provided with a neck portion with a reduced cross section, and which presents a simple construction which allows, not only a tight and safe closure of the can with a high level of tightness, but also the provision of a tamper evident seal, whose manual opening is a requirement for providing a first opening of the lid.

The invention further provides a closure device such as mentioned above and which makes easier and safer the mechanized assembly of the closure device on the can .

The present closure device is applied to cans comprising: a body portion which is joined, by a transition portion, to a neck portion having an upper end edge defining an upper opening of the can and incorporating an outer peripheral ridge; and a lid having an upper edge carrying an outer peripheral rib. According to the invention, the device comprises: a retention ring of plastic material, having an upper annular portion, seated and retained on the outer peripheral rib and superiorly and laterally surrounding the latter, and a peripheral skirt portion externally surrounding the outer peripheral rib and the outer peripheral ridge. The peripheral skirt portion incorporates: an inner peripheral chord seated and retained under the outer peripheral rib, an inner circumferential projection to be seated and retained under the outer peripheral ridge, and a seal strip, interrupted by an axial gap and having an upper edge joined, by breakable connection means, to the lower edge of the peripheral skirt portion, one of the ends of the seal strip incorporating a first end of a circumferential projection superiorly joined, by breakable connection means, to the peripheral skirt portion, and having a free opposite end, which is overlapped and radially spaced in relation to the other end of the seal strip.

The construction defined above allows the closure of the can to be obtained by a simple construction, with the axial locking of the lid by the retention ring and with the provision of a means which is capable of making evident a first opening of the lid, said means being defined by the seal strip extending from the peripheral skirt of the retention ring until next to the transition portion of the can, making practically impossible to release the retention ring from its locking condition under the peripheral rib of the neck portion and consequently, to open the lid, without breaking the circumferential projection of the seal strip .

Brief description of the drawings

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: Figure 1 represents a top plan view of a can, in the condition closed by a lid, the latter being retained in its closed condition by a retention ring peripherally locked under the outer peripheral ridge of the neck portion of the can;

Figure 2 represents a partial longitudinal cross sectional view of the can, taken according to line II- II in figure 1, with the lid in the closed position, and further illustrating the bottom of another identical can stacked on the first;.

Figure 2A represents an enlarged detail of the upper portion of the can illustrated in figure 2 ;

Figure 2B represents a view similar to that of figure 2A, but with the partial cut of the upper portion of the can being taken according to line IIB-IIB in figure 1, said view illustrating the region of the axial gap of the seal strip, onto which region is provided the circumferential projection of the latter; Figure 3 represents a perspective view of the retention ring still not incorporated to the lid, said view being taken in order to illustrate the axial gap of the seal strip and its circumferential projection; and

Figure 4 represents a partial diametral cut view of a stack of retention rings, each already assembled to a respective lid, with the retention ring + lid sets being stacked in the same manner as upon being fed into the magazine of a machine for assembling said sets on cans already filled with the product to be packaged, in order to provide the mechanized closure of the cans .

Description of the Invention

As previously described and illustrated in the attached drawings, the closure device of the invention is applied to a can 10 formed in metallic sheet, usually tinplate, having generally a circular cross section, but which may be polygonal, although said embodiment is not illustrated in the drawings.

The can 10 of tubular shape comprises: a body portion 11, a lower end edge 11a, to which is fixed, usually by double seaming, the peripheral edge of a bottom wall 12; a neck portion 13 having a concentric contour, similar and reduced in relation to that of the body portion 11, and an upper end edge 13a defining the contour of an upper opening "A" for the can 10; and a transition portion 14 with a profile that is inclined in relation to the axis of the can 10 and joining the body portion 11 and neck portion 13. The upper end edge 13a of the neck portion 13 incorporates an outer peripheral ridge 15. In the illustrated embodiment, the outer peripheral ridge 15 has the shape of a curl of tubular cross section, obtained by bending the metallic sheet radially outwards in the region of the upper end edge 13a. In the drawings, the cross section of the curl is circular, however it should be understood that it may be formed a peripheral ridge having different cross sections, which may be tubular or not.

The formation of the body portion 11 is started by forming a tubular body, having a cross section corresponding to that of the neck portion 13 and which is then radially expanded, throughout part of its height, in order to define the body portion 11 and transition portion 14, according to known methods in the art. Preferably, the transition portion 14 remains inferiorly joined to the body portion 11, by a junction region in convex arc 14a, and superiorly joined to the neck portion 13 by a junction region in concave arc 14b.

The can 10 further comprises a lid 20 formed in a single piece of stamped metallic sheet, presenting a panel portion 21, occupying most of the cross section area of the upper opening A and incorporating a peripheral tubular portion 22, which is configured and dimensioned to be fitted, in a tight manner and with interference, into the upper opening A, inside the neck portion 13. Said peripheral tubular portion 22 presents an upper edge 22a, to which is incorporated an outer peripheral rib 25, configured to be seated onto the outer peripheral ridge 15, which is provided in the upper end edge 13a of the neck portion 13.

As illustrated, the lid 20 is preferably built with its panel portion 21 incorporating a pending skirt 21a, usually frusto-conical and which forms, with the peripheral tubular portion 22, a peripheral channel 24, radially spacing the panel portion 21 from the peripheral tubular portion 22, the panel portion 21 thus being located in a higher plane in relation to the bottom wall 24a of the peripheral channel 24.

According to one aspect of the invention, the outer peripheral rib 25 has a partially tubular profile, inferiorly open and having: a radially inner edge 25a which is joined to the upper edge 22a of the peripheral tubular portion 22 of the lid 20; and a radially outer edge 25b, spaced from the radially inner edge 25a, with the outer peripheral rib 25 carrying, in its interior, an annular gasket 30, preferably in the form of a chord made of resin, for example "Plastisol", which is molded inside the outer peripheral rib 25 of the lid 20.

The annular gasket 30 is configured, inside the outer peripheral rib 25, to be seated and pressed against the outer peripheral ridge 15 of the neck portion 13, upon the fitting of the lid 20 into the upper opening A of the can.

Although the drawings illustrate only one outer peripheral rib 25 in the form of a partially tubular curl having the cross section of an arc of a circle, it should be understood that there may be used other cross section shapes.

According to the illustrated embodiment, the radially inner edge 25a and the radially outer edge 25b of the outer peripheral rib 25 define, between each other, an alignment secant to the upper half of the contour of the outer peripheral ridge 15 of the neck portion 13. This constructive form allows the upper portion of the outer peripheral ridge 15 to slightly penetrate inside the lower contour of the outer peripheral rib 25, compressing the annular gasket 30 and assuring a high degree of tightness to the closure da lid 20, upon its fitting into the upper opening A of the can.

Aiming to provide a certain degree of interference between the annular gasket 30 and the upper portion of the outer peripheral ridge 15, the annular gasket 30 is configured to be inferiorly tangent to or sectioned by the lines containing the radially inner edge 25a and radially outer edge 25b of the outer peripheral rib 25 of the lid 20.

As illustrated in the drawings, the subject closure device comprises a retention ring 40, in a single piece of plastic material and having: an upper annular portion 41 seated and retained onto the outer peripheral rib 25 of. the lid 20, superiorly and laterally surrounding said outer peripheral rib 25; and a peripheral skirt portion 42, pending from the upper annular portion 41 and externally and tightly surrounding the outer peripheral rib 25 of the lid 20 and the outer peripheral ridge 15 of the neck portion 13.

The retention ring 40 has an outer face 42d defined in the peripheral skirt portion 42, the latter comprising a lower edge 42a and incorporating an inner circumferential projection 43, to be seated and axially retained under the outer peripheral ridge 15. In the illustrated embodiment, the inner circumferential projection 43 presents a profile in the form of a ramp inclined downwards and radially inwards, so as to define a tooth acting under the outer peripheral ridge 15 of the neck portion 13, in order to provide a safe axial locking of the lid 20 to the body 10 of the can.

In order for the retention ring 40 to remain securely affixed to the lid 20, the peripheral skirt 42 may further incorporate, in its interior, a peripheral chord 44 configured to be tightly seated under the radially outer edge 25b of the outer peripheral rib 25. Thus, the retention ring 40 is incorporated to the lid 20 before the latter is fitted into the upper opening A of the can, upon filling the latter with the product to be canned.

In the illustrated constructive embodiment, the retention ring 40 further incorporates, in its upper annular portion 41, an upper tubular projection 46, radially spaced from the outer face 42d of the retention ring 40 and onto which is seated the bottom wall 12 of another identical can, nested on the first in a stack of said cans, with the outer face 42d of the retention ring 40 acting as an inner radial guide stop for the lower end edge 11a of the body portion 11 of said other can stacked on top of the first.

The retention ring 40 further comprises a seal strip 50 interrupted by an axial gap FA and having an upper edge 50a which is joined, in a single piece and through a weakened junction region 50c, to the lower edge 42a.

One of the ends of the seal strip 50 incorporates, in a single piece, a first end 53a of a circumferential projection 53, having an upper edge 53d, which is joined in a single piece e through breakable connection means 52, to the lower edge 42a of the peripheral skirt portion 42, said circumferential projection 53 having a free opposite end 53b, overlapped e radially spaced in relation to the other end of the seal strip 50, in order to define a grip tab. The breakable connection means 52 are preferably shaped as small axial bridges, joining the lower edge 42a of the peripheral skirt portion 42 to the upper edge 53d of the circumferential projection 53.

According to the illustrated embodiment, the seal strip 50 is located so as to peripherally surround a lower region of the neck portion 13 and an upper region of the transition portion 14, the seal strip 50 having an arcuate profile, externally concave and having a lower edge 50b tangent to a lower region of the transition portion 14, making practically impossible to remove the retention ring 40 from its fitting under the peripheral rib 15 of the neck portion 13, without evidently rupturing the seal strip 50 from the circumferential projection 53 thereof.

In order to facilitate the grip of the circumferential projection 53 of the seal strip 50, the former has the first end 53a thereof joined, by a radial tab 54, to the adjacent end of the seal strip 50.

Due to the arcuate profile of the seal strip 50, the radial tab 54 presents the contour of a right triangle, having a hypotenuse which is arcuate and incorporated to an upper region of the seal strip 50, and a vertical cathetus defining the first end 53a of the circumferential projection 53 of the seal strip 50.

Aiming to facilitate the initial rupture of the seal strip 50, the circumferential projection 53 thereof has the free opposite end 53b provided in a reduced height end region 53c of said circumferential projection 53, defining a grip tab.

Still according to the embodiment illustrated in the drawings, the circumferential projection 53 of the seal strip 50 is defined by a respective cylindrical surface portion, which is radially spaced outward from the adjacent portion of the seal strip 50, the circumferential projection 53 being vertically aligned to an outer face 42d of the retention ring 40, at the region of the peripheral skirt portion 42.

With the construction described above, after removing the seal strip 50, the peripheral skirt portion 42 of the retention ring 40 may be elastically deformed outward, in order to release the engagement between the inner circumferential projection 43 and the outer peripheral ridge 15 of the neck portion 13 of the can, thus allowing the upward displacement of the retention ring 40 and the consequent removal of the lid 20.

Thus, in order for a first opening of the can to occur, it is necessary to break and remove the seal strip 50, such breaking making clearly evident the violation of the closure seal of the can.

As illustrated in figure 4, the retention rings 40 are constructed to allow their stable stacking in a magazine of a machine for the assembly, around the neck portion 13 in a can already filled and of the type considered herein, of said retention rings 40 already incorporated to each respective lid 20.

For this purpose, the upper tubular projection 46, which is radially spaced from the outer face 42d of the retention ring 40, defines, together with the upper annular portion 41, a peripheral step 46a onto which is seated the a lower edge 50b of the seal strip 50 of another retention ring 40 located under the first, in a stack of retention rings 40 already incorporated, each one, to a respective lid 20, with said upper projection 46 of the retention ring 40 underneath acting as an inner guide stop for the lower region of the seal strip 50 of the retention ring 40 positioned immediately above on the stack.

While only one embodiment of the present closure device has been illustrated herein, it should be understood that changes can be made in the form and arrangement of the elements, without departing from the constructive concept defined in the claims that accompany the present disclosure.

Claims

1. A closure device for cans, which comprise: a body portion (11); a neck portion (13) having an upper end edge (13a) defining an upper opening (A) of the can and incorporating an outer peripheral ridge (15); a transition portion (14), joining the body portion (11) and neck portion (13); and a lid (20) including a peripheral tubular portion (22) to be fitted in the upper opening (A) and having an upper edge (22a) carrying an outer peripheral rib (25), the device being character! zed in that it comprises: a retention ring (40) in plastic material, having an upper annular portion (41) seated and retained onto the outer peripheral rib (25) and superiorly and laterally surrounding the latter, a peripheral skirt portion (42) externally and tightly surrounding the outer peripheral rib (25) and the outer peripheral ridge (15), said peripheral skirt portion (42) having a lower edge (42a) and incorporating: an inner peripheral chord (44), seated and axially retained under the outer peripheral rib (25), an inner circumferential projection (43), to be seated and e axially retained under the outer peripheral ridge (15), and a seal strip (50), interrupted by an axial gap (FA) and having an upper edge (50a) which is joined, in a single piece and through a weakened junction region (50c), to the lower edge (42a) of the peripheral skirt portion (42)^', one of the ends of the seal strip (50) incorporating, in a single piece, a first end (53a) of a circumferential projection (53) having an upper edge (53d) which is joined, in a single piece and through breakable connection means (52), to the lower edge (42a) of the peripheral skirt portion (42), said circumferential projection (53) having a free opposite end (53b), overlapped e radially spaced in relation to the other end of the seal strip (50) .

2. The device, as set forth in claim 1, characterized in that the seal strip (50) peripherally surrounds a lower region of the neck portion (13) and an upper region of the transition portion (14), and presents an arcuate profile, externally concave and having a lower edge (50b) tangent to the lower region of the transition portion (14).

3. The device, as set forth in claim 2, characterized in that the circumferential projection (53) of the seal strip (50) has the first end (53a) thereof joined, by a radial tab (54), to the adjacent end of seal strip ( 50 ) .

4. The device, as set forth in claim 3, characterized in that the radial tab (54) presents the contour of a right triangle, having a hypotenuse which is arcuate and incorporated to an upper region of the seal strip (50) and a vertical cathetus defining the first end (53a) of the circumferential projection (53) of the seal strip ( 50 ) .

5. The device, as set forth in any of the claims 1 to

4, characterized in that the circumferential projection (53) of the seal strip (50) has the free opposite end (53b) thereof provided in an end region of reduced height (53c) of said circumferential projection (53), defining a grip tab.

6. The device, as set forth in any of the claims 1 to

5, characterized in that the circumferential projection (53) of the seal strip (50) is defined by a respective cylindrical surface portion radially spaced outwards from the adjacent portion of the seal strip (50) .

7. The device, as set forth in any of the claims 1 to 6, characterized in that the circumferential projection (53) of the seal strip (50) is vertically aligned to an outer face (42d) of the peripheral skirt portion (42) of the retention ring (40) .

8. The device, as set forth in any of the claims 1 to 7, characterized in that the outer peripheral rib (25) of the lid (20) presents a partially tubular shape, interiorly open and having a radially inner edge (25a) and a radially outer edge (25b) and carrying, in the interior thereof, an annular gasket (30), to be seated and compressed against the outer peripheral ridge (15) of the neck portion (13), upon fitting the lid (20) in the upper opening (A) of the can.

9. The device, as set forth in claim 8, characterized in that the outer peripheral rib (25) has the radially inner edge (25a) and the radially outer edge (25b) thereof defining, between each other, an alignment secant to the upper half of the contour of the outer peripheral ridge (15) of the neck portion (13) .

10. The device, as set forth in claim 9, characterized in that the annular gasket (30) is inferiorly tangent or sectioned by lines containing the radially inner edge (25a) and radially outer edge (25b) of the outer peripheral rib (25) of the lid (20) .

11. The device, as set fqrth in any of the claims 1 to 10, characterized in that the body portion (11) presents a lower end edge (11a) to which is double seamed a bottom wall (12) of the can, the retention ring (40) presenting an outer face (42d) in the peripheral skirt portion (42) thereof and further incorporates, in the upper annular portion (41) thereof, an upper tubular projection (46) onto which is seated the bottom wall (12) of another identical can, nested on the first in a stack of said cans, with the outer face (42d) of the retention ring (40) acting as an inner radial guide stop for the lower end edge (11a) of the body portion (11) of said other can.

12. The device, as set forth in claim 11, characterized in that the upper tubular projection (46) is radially spaced in relation to the outer face (42d) of the retention ring (40) and define, with the upper annular portion (41), a peripheral step (46a) onto which is seated the lower edge (50b) of the seal strip (50) of another retention ring (40) located under the first, in a stack of retention rings (40), each already incorporated to a respective lid (20), with said upper projection (46) of the retention ring (40) underneath acting as an inner guide stop for the lower region of the seal strip (50) of the retention ring (40) positioned immediately above on the stack.