BRPI0802598A2 - tin can lid - Google Patents

Abstract

METAL COVER FOR CAN. The lid (20) in question comprises a bottom wall (21) incorporating a side wall (22) to be seated and axially retained within a seat (S) defined by an opening (14) of the can (10). The bottom wall (21) comprises a peripheral annular portion (23)), a median portion (24), and an approximately inverted "U" shaped annular portion (25) joined to the peripheral annular portions (23) and median (24). The median portion (24) comprises an annular panel (24a) and a central panel (24b), joined together by an axial step portion (24c), with an outer peripheral edge of the annular panel (24a) being incorporated into the frieze. (25), said axial step portion (24c) being comprised of plastically deformed material from adjacent portions of the annular (24a) and central (24b) panels.

Description

"METAL COVER FOR CAN"

Field of the invention

The present invention relates to a metal end cap having a peripheral side wall providing a free upper edge and being frictionally seated and axially retained within a sediment defined in an upper can opening, and may even optionally be provided in its region. of an inspection opening to receive an auxiliary cover generally made of clear plastic material.

Prior art

Metal lids of the above type, formed in one piece of metal foil and comprising a generally disc-shaped bottom wall, whose peripheral edge incorporates a side wall projecting towards, are well known. above, to be removably snapped and axially retained within a seat defined in an upper opening of a can, said seat being defined by a pendular tubular projection, superiorly incorporated into a median opening of the upper wall of a circular cross-sectional can or polygonal.

Metal caps of the aforementioned type are described and illustrated in patent documents US2.074.231, US3.34 7.4 08, BR-MU8 002 622-2, BR-MU80 02 618-4

and also in the patents BR-PI9408643-5 and BR-MU7601221-2, the latter two having as their proprietor the patent application filed in question.

In such prior art constructions, the datamp structure comprises only the bottom wall and a peripheral sidewall, the axial retention of the nascent lid defined in the upper can opening generally being achieved by engaging means provided in at least one of the sidewall portions of the can. lid and seat in the upper openings, to cooperate with the other party.

In the construction of the aforementioned type, even when the bottom wall of the lid exhibits a medium swell rise or rise, as with the solution described in patents BR-MU 7601221-2 and US 3,347.4-8, the datamp structure requires some care. when closing forces are applied, without which the lid can be irreparably damaged, preventing a tight and secure can closure from being obtained.

The aforementioned structural deficiency results from the fact that said lid construction does not have the usual peripheral structure guaranteed in the metal caps provided with a peripheral annular recess, generally substantially trapezoidal invertidae cross-sectional being frictionally seated within a complementary defining cross-section undercut. seat incorporated into the annular upper wall of a tinplate, as occurs in the construction known decades ago, and described and illustrated in US 795,126, filed in 1904.

In order to increase the structural strength of known caps, which have only the bottom wall and a peripheral sidewall shaped to be seated and retained axially in an upper can opening, the constructive solution described and claimed in patent application PI0405458-0 has been proposed, according to which the bottom wall of the lid comprises a peripheral annular portion and a median portion

interconnected by a portion of annular frieze, approximately inverted U-shaped. This prior construction impresses the lid, formed of sheet metal of a certain thickness, an increased structural strength, bypassing the deficiency of these known caps without

require increased sheet metal thickness. Provision of the annular portion of the bottom wall as proposed in PI0405458-0 leads to increased structural strength of the lid.

However, even with the incorporation of the ring trim portion in the bottom wall of the lid, the structural strength required for proper and safe lid operating behavior still requires a certain minimum thickness of sheet metal.

Summary of the invention

In view of the above with respect to the prior art, the present invention has as one of its objectives to provide a metal cap of the above type and provided with an annular frieze on the bottom wall and having an increased strength to the extent that it permits the construction of such materials. Thin foil covers, although this reduces the structural strength to values below those expected or desired so that the closure can be closed and opened by the usual procedures, without the risk of useless plastic deformation.

This and other objects of the present invention are achieved by providing a standard metal cap having its bottom wall comprising a peripheral annular portion adjacent to the lid side wall, a median portion and an annular crimp portion having a roughly shaped cross section. inverted "U" shape, its lower side flaps being respectively incorporated into the adjacent edges of the peripheral and median annular portions of the back wall. According to the invention, the middle portion of the deep wall comprises an annular panel and a central panel joined by a portion. An outer peripheral edge of the annular panel is incorporated into the adjacent side flap of the annular frieze portion, the axial step dipole being constituted by a substantially deformed material of the adjacent portions of the annular and central panels.

With the construction generally defined above, in addition to the median and annular peripheral portions of the dalata back wall being joined together by said annular frieze portion, the median portion now incorporates the rachuaxial into its radially median region, an axial step defining one more element structural structure incorporated into the back wall itself and distanced from the sidewall of the lid.

The provision of the auxiliary step, in addition to the provision of the annular frieze portion, gives the lid a structural strength considerably higher than that achieved with the aforementioned prior art constructions, allowing for the obtainment of suitably strengthened, sheet-metal lids of less thickness, i.e. lower material consumption.

In addition, the construction of the lid, object of the present invention, may be made such that the central panel of the median bottom wall portion has an inspection opening defining a seating seat and axial retention of an auxiliary lid of transparent plastic material.

Brief Description of Drawings

The invention will now be described with reference to the accompanying drawings, given by way of example of the constructions of the lid in question and in which:

Fig. 1 is a diagrammatic cross-sectional view of the upper region of a can in which the extreme pouring opening is fitted with a cap constructed in accordance with one of the known prior art solutions;

Fig. 2 is a top plan view of a cap of the type illustrated in Fig. 1, but incorporating the axial degree according to a first embodiment of the invention;

Figure 3 is a partial diametric sectional view of the lid when mounted on the extreme open-can opening of a can, said view having been taken according to line 111-111 in figure 2.

Fig. 4 is a top plan view of a cap of the type illustrated in Fig. 2, but incorporating radial extensions of the center panel according to a second embodiment of the invention;

Figures 5 and 6 are diametral sectional views of the lid when mounted on the extreme open-can opening of a can, said views having been taken along line V-V and VI-VI, respectively, in Figure 4;

Figure 7 is a top plan view of a third lid configuration of the present invention; and Figure 8 is a diametral-sectional view of the lid when mounted on the extreme open-can opening of a can, said view having been taken according to line VIII-VIII in figure 7.

Detailed Description of the Invention

As illustrated in the accompanying drawings, the lid in question is applied to a can 10, represented graphically only by the upper portion of its sidewall 11, to which the upper edge is fixed, usually by means of a recess 12, an outer peripheral edge of an annular upper wall 13 on the side. whose median region is provided with an opening 14 in which the rim is incorporated with a hanging tubular projection 15 defining a can lid seating seat "S".

In the prior art construction exemplified in FIG. 1 of the drawings and which is the subject of patent application BR-PI9408643-5 of the applicant in question, the pending tubular fitting 15 is provided with an extreme lower portion curved into the opening 14, above and above. against the hanging tubular projection 15, it is formed to form a continuous tubular rib 16 which is generally circular in shape, as described in the above patent.

It should be understood, however, that the construction of the hanging tubular projection 15 of the annular upper wall 13 of can 10 may follow different arrangements, as illustrated and discussed in the aforementioned prior art documents, without such constructive modifications altering the constructive-functional purposes of the present invention.

As previously mentioned, the lid 20 of the present invention is formed of a single sheet metal part, comprising a generally flat disc shaped bottom wall 21 incorporating, upper and peripherally, a side wall 22 providing free upper edge 22a and to be frictionally seated and axially retained within the "US" seat defined by the hanging tubular projection 15 of the opening 14 provided in the annular upper wall 13.

In the exemplary construction illustrated in the drawings, cap 20 has its sidewall 22 provided with a continuous recess 22b, into which the continuous tubular nerve 16 of the pending tubular projection 15 is visibly engaged and axially retained. In the illustrated construction both the continuous tubular rib 16 of the pendant tubular projection 15 as the continuous recessperipheral recess 22b of the sidewall 22 of the lid 20 have an at least partially circular and complementary contour, so that the mutual seating of said parts not only promotes the axial retention of the lid 20 in the opening 14 of the can 10, as well as a sealing effect on that frictional settlement region. It should be understood, however, that the continuous tubular rib 16 and continuous peripheral recess 22b may have different configurations from the circular tubular illustrated in the drawings, as can be seen in the earlier documents cited at the beginning of the present descriptive report.

Still according to the embodiment illustrated in the drawings, the lid 20 has free upper edge 22a curved outwardly downwardly against side wall 22 so as to define a tubular upper rib 22c to be seated over annular upper wall 13 of the can 10, in the region surrounding the opening 14. Similarly, it should be understood that the free upper edge 22a of the sidewall 22 of the lid 20 may have different constructive shapes, as illustrated in the prior art and prior art representative documents, without such shape and shape modifications. the disposition of the superior lateral wall region 22 datamp 20 alter the functional characteristics of the proposed invention.

According to the invention, the bottom wall 21 of the lid 20 comprises a peripheral annular portion 23 adjacent to the sidewall 22, a median portion 24 and an annular rib portion 25, having an inverted "U" shaped cross-section having its lower side flaps. and respectively incorporated into adjacent edges of the peripheral annular portions 23 and median 24 of the bottom wall 21.

The annular frieze portion 25 is stamped together with the cap shoulder 20 so as to preferably project above the peripheral 23 and median annular portions 24 of the bottom wall 21, with the annular frieze portion 25 remaining spaced from said sidewall 22 by a suitable distance to give the lid region 20 the necessary structural rigidity to resist the compressive forces to be applied to the lid 20 when it engages with the opening 14 of the can 10.

Still according to the preferred embodiment, the median portion 24 of the bottom wall 21 is arranged in an elevated plane relative to a plane containing the peripheral annular portion 23 of said bottom wall 21. This constructive arrangement allows the mid portion 24 of the bottom wall 21 operates, in conjunction with the annular portion 25, to define means of seating one lid over another when stacking the same in a lid release magazine on a machine for automatically closing the cans or automatically snapping the lids 20 together thereon. upper wall 13, before the cannulation of the cans 11.

The annular frieze portion 25 is further constructed and sized to be disposed inferiorly to a plane Ps containing the free upper edge 22a of the sidewall 22 of the lid 20, which is a relative dimensioning of the lid parts made as a function of the aforementioned stacking characteristics. edited in PI 0405458-0.

In accordance with the present invention, the middle portion 24 of the bottom wall 21 comprises a generally flat annular panel 24 having an outer peripheral edge which is incorporated into the adjacent side flap of the annular frieze portion 25 and an inner peripheral edge incorporated by a step portion 24c, to an outer peripheral edge of a central panel 24b also generally planar and arranged in a plane slightly larger than that of annular panel 24a.

In order for the lid 20, having the axial step portion 24c, to be formed from a sheet metal blank of the same size as that required for the production of the lid defined in Figure 1 and provided with the annular rim portion 25, the step portion 24c is comprised of plastically deformed material from the adjacent portions of the annular and central panels 24a. The provision of axial step portion 24c increases the structural strength of the lid 20, particularly of its back wall 21, to a degree sufficient to allow the usual sheet thickness. The lid's metal surface will be reduced without the structural resistance of the lid leading to unacceptable values or detrimental to the correct and safe closing and opening operations of the can through the lid.

In the configuration illustrated in FIGS. 2 and 3, the center panel 24b is fully closed and devoid of any opening, having a radius R corresponding to about double the radial width RL of annular panel 24a.

The height of the axial step 24c should be sufficient only to produce the desired effect of increasing the structural strength of the lid 20, and is generally approximately equal to the thickness of the lid deformation sheet 20 so that the forming material results exclusively from the material. deformed plastic during the stamping operation of the adjacent regions of the annular panel 24a and central panel 24b.

In the second embodiment illustrated in FIGS. 4, 5 and 6, the central panel 24b of the mid portion 24 of the lid 20 incorporates a plurality of radial extensions 24d, coplanar to said central panel 24b and extending to the adjacent side flap of the annular frieze portion 25 to which are incorporated. In the illustrated embodiment the radial extensions 24d are four in number, it should be understood that this number may vary more or less, and it is only desirable that said radial extensions 24d are equal to and spaced apart from one another. It is further possible to cover the lid 20 so that the radial extensions 24d of the central panel 24b are arranged in a slightly axially offset plane of the plane of the central dipop 24b.

In the embodiment illustrated in FIGS. 7 and 8, the center panel 24b is provided with an inspection opening 26 radially spaced from the axial step 24c, defining a seating and axial retention of a peripheral wall 31 of an auxiliary lid 30 in transparent plastic material, said inspection opening 26 comprising a pendant skirt 27 shaped to incorporate an inner circumferential rib 28 to be fitted into a corresponding circumferential recess 33 provided in the peripheral sidewall 31 of the auxiliary cover The construction of the inspection opening 26 and the auxiliary cover 30 may follow the same line applied to the lid 20, while maintaining the dimensions of the involved parts proportionally adequate to the smaller diameter of the auxiliary lid 30. It should be understood that the radial extensions 24d of the central panel 24b, in this case also parallel, can also be provided in the configuration illustrated in figures 7 and 8

In the embodiment illustrated in the drawings, the peripheral portion 23 and the middle portion 24 of the bottom wall 21 of the lid 20 are flat.

Although only a few constructive shapes for the lid have been illustrated, together with a seat construction, it should be understood that shape changes of the component parts may be made without departing from the constructive concept defined in the accompanying claims.

Claims (10)

1. Metal lid to be applied to a can (10) having an opening (14) defining a seat (S), said lid (20) comprising, in a single piece of metal foil, a bottom wall (21) incorporating, upper peripherally, a side wall (22) provided with free upper edges (22a) and being frictionally seated and retained within the seat (S), said deep wall (21) comprising a peripheral annular portion (23) adjacent to the side wall (22). ), a median portion (24) and an annular frieze portion (25) with an inverted "U" shaped cross-sectional section and its lower lateral flaps and respectively incorporated with the adjacent edges of the annular (23) and median (24) portions. of the bottom wall (21), said lid (20) is characterized in that the median portion (24) comprises an annular panel (24a) and a central panel (24b) joined by a portion of degr (24c), whereby an outer peripheral edge of the annular panel (24a) is incorporated into the adjacent side flange of the annular fringe portion (25), said degrauaxial portion (24c) being formed of plastic material formed from the adjacent portions of the annular panels. (24a) and central (24b). Lid according to claim 1, characterized in that the radial width (RL) of the annular panel (24a) corresponds to about half the radius (R) of the central panel (24b). Lid according to any one of claims 1 or 2, characterized in that the axial step (24c) has a height approximately equal to the thickness of the lid forming metal sheet. Lid according to any one of claims 1, 2 or 3, characterized in that the ring-rim portion (25) protrudes above the annular (23) and median (24) portions of the back wall ( 21). Lid according to Claim 4, characterized in that the median portion (24) of the bottom wall (21) is arranged in an elevated plane relative to a plane containing the peripheral annular portion (23) of said bottom wall. (21). Lid according to Claim 4, characterized in that the annular frieze portion (25) is disposed below a plane (Ps) containing the upper free edge (22a) of the side wall (22) of the lid (20). Lid according to any one of claims 1 to 6, characterized in that the annular panel (24a) and the central panel (24b) are flat, the latter being arranged in a plane slightly larger than that of the annular panel (24a). Lid according to any one of claims 1 to 7, characterized in that the central panel (24b) is provided with an inspection opening (26) spaced apart from the axial step (24c), defining a seating seat and axial retention of the same. a peripheral side wall (31) of an auxiliary cover (30) of transparent plastic material, said inspection opening (26) comprising a hanging skirt (27) shaped to incorporate an inner circumferential rib (28) to be fitted into a corresponding circumferential recess (33) provided on the peripheral sidewall (31) of the auxiliary lid (30). Cap according to any one of claims 1 to 8, characterized in that the central panel (24b) of the median portion (24) of the cap (20) incorporates a plurality of radially extending radially extending (24d) extents (24d). to the adjacent abalateral portion of the annular frieze portion (25) to which they are incorporated. Cover according to claim 9, characterized in that the radial extensions (24d) are coplanar to the central panel (24b).