MXPA00010437A - Container lid and method for making same - Google Patents

Abstract

A method and apparatus for making a container lug lid which minimizes scrap waste is described. The blanks for forming container lug lids therefrom comprise an odd number of dissimilar lugs with one or more of the lugs comprising a male lug. Circumferential bases are formed betweeen each lug, with one or more of the circumferential bases having a female complementary shape for receiving a male lug of an adjacent blank. The blank pattern for cutting the blanks from a sheet of material, which is preferably scrolled, comprises arranging the blanks in a closely spaced arrangement with the male lugs positioned for alignment with an adjacent female or complementary shaped circumferential base.

Description

CONTAINER COVER AND METHOD TO MANUFACTURE FIELD OF THE INVENTION The present invention relates generally to lid closures for use with cylindrical containers. More particularly, the invention relates to metal lid closures having a plurality of ears that are folded for closing and sealing the ends of a bucket or container, and to a method for making the same.

BACKGROUND OF THE INVENTION Many types of container covers have been designed in the prior art to close buckets or containers. Typically, these container covers are applied to a bucket or container with open ends having a curved annular rim formed around an open end. In general, the covers in the prior art are disc-shaped and have an outwardly facing annular groove or channel adapted to receive the annular rim of the container. A series of lugs on the lid come down from the annular channel of the lid to secure the lid to the rim of the container. For example, lids with ears that are used in containers of two and a half to seven gallons generally contain an even number of ears in the order of 16 to 20 ears, which are formed along an edge ears in the order of 16 to 20 ears, which are formed along a circumferential edge of the lid with spaces formed between the ears. The lid is sealed to the container using a folding tool to bend the ears around the annular rim of the container in a sealing arrangement. Generally, the metal container covers are manufactured by preforming or die cutting a rectangular or square metal sheet with a pattern comprising a plurality of caps or preforms of the container not bent. For example, in Fig. 1 a typical die-cutting pattern of the prior art is shown, consisting of four closely spaced non-folded container covers having a symmetrical shape. One of the main disadvantages in the design of the container lid and the die-cutting pattern in the prior art is that the material that is wasted between the orifices is very expensive (i.e., the excess material) even though the preforms are closely separated from each other. In addition, a long sheet of material is required in order to produce a number of container covers. This waste is a function of the design of the lid of the container and the amount of spaces divided into lots for the adjacent preforms. The waste material represents a costly loss that is only partially recoverable and which requires additional resources to convert it into a reusable form. Another disadvantage of the prior art is that it takes more time to collect and transport the waste to the recycling centers. A further disadvantage of the prior art is that the paint used to cover the sheet before die-cutting is worn out as well as the additional energy required to renew the paint on a long sheet. Therefore, it is desired to provide an improved design of the container lid and a preform pattern design that reduces the amount of waste material generated and thus result in considerable cost savings with very few disadvantages. It is also desired to provide an improved container lid design and a preform pattern design that reduces the sheet size of the material while producing an equivalent number of lids.

BRIEF DESCRIPTION OF THE INVENTION According to the teaching of this invention, a container lid is provided, together with a process for the manufacture thereof in which the lid of the container is capable of being manufactured at low cost generating a minimum waste of material and while they have the advantages obtained by the container covers of the prior art. The invention provides an aspect of the lid with ears to seal a container having an annular curved rim, the lid with lugs comprises a flat surface having an annular channel on the peripheral rim of said lid; a plurality of ears coming down from an outer wall of the channel; one or more of said ears being asymmetric with respect to the other ears; and a plurality of circumferential bases formed between the adjacent ears. The lid with ears provides in another aspect a lid with ears comprising a flat surface having an annular channel on a peripheral edge of said lid; an odd number of ears emerging from an outer wall of the channel with one or more of said ears comprising a male ear; and a plurality of circumferential bases formed between the adjacent ears with one or more of said circumferential bases comprising a female matching space. The lid with ears provides in another aspect of the invention an odd number of lid ears having at least some of these ears formed in a shape different from the other ears of the lid. The ends of the ears can be bent or curled to facilitate the removal of the container lid. The invention provides in another aspect a method for making a plurality of container covers comprising the steps of forming one or more lid preforms, each preform comprising a plurality of ears on a peripheral edge of said preforms, a plurality of circumferential bases formed between each of said ears, one or more of said ears comprising a male ear and one or more of said circumferential bases having a complementary female shape to correspond with the male ear; placing the preforms of the lid on a sheet of material such that each male ear of an adjacent lid preform is aligned and located within said matching circumferential base of an adjacent lid preform; cutting the preforms of the lid from a sheet of material; and forming a container lid with each of said preforms. The invention still provides in another aspect a method for manufacturing container covers comprising the steps of: forming two or more lid preforms having a plurality of ears on the peripheral edge of the preform, with a plurality of circumferential bases formed between each of the ears, placing the preforms of the lid on said sheet of material in such a way that one or more of said ears of a lid preform are interlocked with respect to the ears of an adjacent preform, cutting a plurality of cover preforms of a sheet of material; and forming a container lid with each of said preforms. The invention provides in another aspect plus a container lid prepared by the method comprising the steps of forming a plurality of lid preforms, each preform comprising a plurality of ears on a peripheral edge of said lid, a plurality of circumferential bases formed between each of said ears, one or more ears comprise a male ear, and one or more of said circumferential bases having a complementary shape to correspond with the male ear; placing the lid preform patterns on a sheet of material such that the male ear of an adjacent lid preform is positioned within said circumferential base complementary to an adjacent lid preform; cutting the preforms of the lid placed from a sheet of material; and forming a container lid of each of the preforms. The method in another aspect of the invention uses a specially configured sheet of material designed in conjunction with the configuration of the cover preforms substantially to maximize the utilization of the sheet material. In one form, the material of the sheet has rectangular aligned end sections with a central offset portion, the deflection being formed by a trapezoid of material that is added to and extending outwardly from a margin of the sheet while a trapezoidal recess of the sheet. Same size and shape is provided in the other margin. This shape of the material allows at least three rows of lid preforms placed on the material, with the deviation of the central row from the upper and lower rows to allow adjacent ear preforms in the rows to be more closely spaced from each other.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: Figure 1 is a plan view of the schematic layout in the prior art of the preforms of the lid of the container; Figure 2 is a perspective view of the design of the container lid of the present invention adapted to the container of the prior art; Figure 2A is a perspective view of a portion of the design of the lid of the container showing the other side of the lid in Figure 1; Figure 3 is a cross section of the lid of the container of the present invention taken in the plane 2-2 as shown in the figure 1; Figure 4 is a plan view of the design of the preforms of the lid of the container of the present invention; Figure 5 is a plan view of a preform of the lid of the individual container of the invention; Figure 6 is a very elongated portion of Figure 4 showing the abutting surface of the matching ears of the preforms of the adjacent container; Figure 7 is a plan view of an alternative embodiment of the preform pattern design of the lid of the container of the present invention; and Figure 8 is a plan view of an alternative embodiment of the preform pattern design of the lid of the container of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES With reference to the figures, and more particularly to Figures 2 and 3, a new and improved container lid 10 is illustrated for use in conjunction with the prior art containers 20 normally made of plastic or metal. These prior art containers 20 are suitable for storage and transportation of paints, liquids and other flowable materials under hermetic sealing conditions. These containers or trays 20 of the prior art are generally formed of sheets of steel or other resistant materials and comprise a cylindrical container body 22 having side walls, a conventional closed bottom end (not shown) and an open top end 24 which cooperates to define a storage chamber. Generally the open top end 24 has a curved annular flange 26 which is formed of a corrugation of rolled material or other suitable material that is adapted to receive a cap with ears 10. The cap with ears 10 of the invention generally comprises a flat surface 30. preferably having a circular or disk shape having a plurality of annular reinforcing tabs 11 and an annular downwardly facing channel 32 comprising a high inverted U-shaped cross-section forming an outer peripheral edge 34 of the lid with ears 10. The annular channel 32 is adapted to fit over and sit on the annular rim 26 of the container 20, with the annular rim 26 being received in the annular recess of the channel 32. An optional package (not shown) is It can sit and fix with conventional means in the annular channel. Once the lid 10 is seated on the rim of the container, a plurality of lugs 40 are folded along the annular rim 26 of the container 20 such that the lid is sealed in the coupling with the container 20. The ears 40 they are formed around the periphery of the lid with ears 10, coming down from the outer wall 42 of the annular channel 32. The lid with ears 10 of the invention preferably has an odd number of ears 40, usually in the range of 13. to 17, and preferably 15 ears, many of which have a unique shape. In contrast, ear configurations in the prior art (not shown) generally provide an even number of identically shaped ears, in the order of 18 to 20 ears per cap. The lugs 40 of the invention overlap the rim 26 of the container 20 when the lid 10 is seated on the rim 26. The shapes of most of the lugs 40 are generally rectangular with round or circumferential edges 43 terminating in the flat edge 44. Nevertheless, many other ear shapes would work for the invention. An optional tabular end 45 may be formed on the flat edge 44, which may be formed or bent in an upward waviness 46 in order to facilitate the opening of the folded ears 40. Optional ripple 46 may be used to leverage the aperture the ears folded in order to release the lid 10. The circumferential bases 48 are interspaced between each of the ears 40 that exists between each ear 40 in order to assist in the folding of the ears 40 around the ripple of the rim 26 of the container 20. • However, in contrast to the prior art, not all ears 40 are identical in shape. Almost all the ears 40 have different shapes and vary in width. As shown in Figure 5, the preform design of the lid 50 has a plane of symmetry 52 due to the odd number of ears and the unique shape of each ear. Starting with the ear 54 in the clock position at 9 o'clock, the ear 54 has a curved edge 43, one end tabular 45 and a truncated upper edge 55 which are connected to an elongated circumferential base 56 formed between the ear 60 and the ear 54. An edge . truncated 58 of the ear 60 is connected to the elongated circumferential base 56 formed between the ear 60 and the ear 54. These truncated edges 55, 58 in combination with the elongated circumferential base 56 form a base matching female 51 which is used to facilitate the interlacing of the preforms of the lid 50 as shown in Figure 4, and as explained P in more detail below. The design of the ear 60 is thus the mirror image of the ear 54, each of which further comprises a tabular end 45 connected to the truncated edge 55, 58 and at one end round 43 next to the tabular end 45. The ears 64, 68, 72, 76 and 80 are very similar in shape as a rectangle with rounded edges 43 with a tabular end 45 formed on the outer peripheral edge. The circumferential bases 48 of different widths are formed between the adjacent ears. The ears 64 and 68 are slightly inclined with each other, since the ears 76 and 80 are inclined outwardly with one another in such a way that interdigitation is facilitated, as explained in more detail below. The ear 84 is also approximately rectangular in shape with a rounded edge 43 at one end and an edge 85 that is partially rounded and partially truncated closer to the circumferential base formed between the ears 84 and 88. The ear 88 is pyramidal in shape. , that is to say it has the inclined edges 89 attached to a circumferential edge 90 which is in the middle and which form a male ear for production purposes. The ears 94 to 114, due to the plane of symmetry, are mirror images of the ears 84 to 60, respectively. For example, the ear 94 is the mirror image of the ear 84, the ear 98 is the mirror image of the ear 80, etc. The die pattern of the preforms of the conventional lid as shown in Figure 1 demonstrate that the preforms of the stage of the container are sufficiently separated so that the preforms do not touch each other on either side and are arranged around the same distance with each other. Therefore, blanking the lids of the material necessarily results in the production of a residual die-cutting template or waste material that can be used only as waste. Furthermore, for a certain size of lid, a larger area of material surface is required for the same number of container covers for the prior art design as compared to the design of the invention. Figure 4 shows the die-cutting pattern of six container cover preforms 50 of the invention of a deployed metal sheet. Figure 4 illustrates three rows of preforms of the container lid comprising 2 lid preforms in each row, with the middle row being deflected from the upper and lower rows. In each row, the male ear 88 of the preform of the container lid aligns with, and is placed between the female circumferential base 51 formed between the ears of the preform of the adjacent container lid, leaving a very thin leftover material as is shown in Figure 6. The ears of the preform of the lid of the container in the adjacent rows are aligned and placed closely between the circumferential bases of the preforms of the container lid nearby. Thus the ears of the container lid are interdigitated or interlaced with the ears in the adjacent rows, analogous to gear teeth between matching gears. This relationship between the respective preforms of the lid and the rows of lids minimizes the amount of material between the preforms of the lid and thus the remaining excess material is minimized when the lids have been removed from the sheet material. The design of the odd number of specially configured lid ears, the design of the preforms of the cover and the preform rows of the deflected cover and the shape of the sheet material contribute to the efficiency of the process. In the preferred form of the unfolded sheet material, indicated generally as 120, it has two rectangular ends 122 and 124 and a central deviated section, indicated generally as 126. The deviated central section 126 is formed by a trapezoidal part 128 which is added to which extends outwardly from one of the sides or margins of the material of the sheet 120 and a similarly formed lateral trapezoidal recess 130 that is provided on the other side. In an alternative embodiment of the invention, the preform of the container lid 50 may comprise three or more female circumferential bases 51 and three or more male-shaped ears 88, as shown in Figure 7. The male ears 88 and Female circumferential bases 51 are alternated on a preform of the container lid 50. As can be seen, the design of the preforms of the container 50 in the middle row is such that the female circumferential bases 51 and the male ears 88 are placed to align with the adjacent male ears 88 and the female circumferential bases 51. In yet another alternative embodiment of the invention, as shown in Figure 8, the preform of the lid of the container 140 comprises an odd number of ears symmetrically formed 143 with circumferential bases 144 formed between each of the ears. Preferably, the preforms have 15 ears, each ear having the same angular displacement a. In addition, it is preferred that the circumferential bases 143 be the same. The ear 146 is symmetrically shaped, although it has a narrower tabular extension 148 than the tabular extensions 150 of the other ears 142. Opposite ears 146 are two adjacent ears 144, which are inclined outwardly with each other to allow the ear 146 is placed between, or interlocked with respect to, adjacent ears 144 on an adjacent preform when the preforms are deployed. In addition, the ears 142 are additionally interlaced with respect to the ears 142 on an adjacent preform at the locations identified by the letter "B". Thus, the preforms of the container 140 are preferably arranged on a sheet of unfolded material 120 as described above, with the preforms arranged in two or more rows in a very separate configuration. The middle row is derived from the outer rows to allow a closer division of the preforms 140. In addition, each row has the preform ear 146 interlaced with respect to the adjacent preform ears 144. Although the invention has been described With respect to certain preferred embodiments, certain variations and modifications may occur to those skilled in the art upon reading this specification. For example, the invention could be used on a cover that is not round or that contains an annular channel or an annular flange section. Some of these variations and modifications are within the scope of the invention even though the limitations of the appended claims and equivalents thereof are defined.

Claims (27)

NOVELTY OF THE INVENTION CLAIMS

1. - A lid with ears to seal a container having a rim, the lid with ears comprises: a flat surface having a channel on a peripheral edge of said lid; a plurality of ears emerging from an outer wall of the channel; one or more of said ears being asymmetrically formed with respect to other ears; and a plurality of bases formed between the adjacent ears.

2. The lid with ears according to claim 1, further characterized in that said lid has a plane of symmetry.

3. The lid with ears according to claim 1, further characterized in that said lid has only a plane of symmetry.

4. The lid with ears according to claim 1, further characterized in that one or more of said ears is a male ear and one or more of said bases are female.

5. The lid with ears according to claim 1, further characterized in that said lid comprises a first half and a second half with each half being the mirror image of the other half; with the ears in said halves being only formed.

6. - The lid with ears according to claim 1, further characterized in that all the ears are asymmetrically formed.

7. The cap with ears according to claim 1, further characterized in that it comprises an odd number of ears.

8. The lid with ears according to claim 1, further characterized in that one or more ears are inclined.

9. The cap with ears according to claim 1, further characterized in that said cap is generally disc-shaped.

10. A lid with ears comprising: a flat surface having a channel or a peripheral edge of said lid; an odd number of ears emerging from an outer wall of the channel with one or more of said ears comprising a male ear; and a plurality of circumferential bases formed between adjacent ears with one or more said circumferential bases comprising a female matching space.

11. The lid with ears according to claim 10, further characterized in that said male ear comprises a generally pyramidal shape.

12. The cap with ears according to claim 10, further characterized in that said female matching space has a generally pyramidal shape.

13. The cap with ears according to claim 10, further characterized in that one or more of said ears are inclined outwardly from an adjacent ear.

14. - The lid with ears according to claim 10, further characterized in that some of these ears are generally rectangular in shape and with rounded edges.

15. The cap with ears according to claim 10, further characterized in that it also includes a corrugation at the end of at least some of the ears to facilitate the removal of the lid of the container.

16. The cap with ears according to claim 10, further characterized by comprising 15 ears.

17. The cap with ears according to claim 10, further characterized by having a circular shape.

18. A lid with ears for closing an open end of a container comprising a generally flat surface and a plurality of an odd number of ears emerging from the periphery of the generally flat surface, at least one of said ears having a different shape from the other ears.

19. A method for making a plurality of container covers comprising the steps of: forming one or more preforms of lids, each preform comprises a plurality of lugs on a peripheral edge of said preform, a plurality of circumferential bases formed between said lugs. ears, one or more of said ears comprise a male ear, and one or more of said circumferential bases having a complementary female shape to correspond with said ear 1 male; placing the preforms of the lid on a sheet of material such that each of the male ears of the lid preform are aligned and positioned within the matching circumferential base of an adjacent lid preform; and cutting said lid preforms from the sheet of material and forming a container lid with each of said preforms.

20. The method according to claim 19, with the placing step further comprises placing the preforms of the lid on a sheet of material deployed in two or more rows closely spaced, with the preforms of the cover in each row having their aligned centers and each row being diverted from an adjacent row.

21. A method for making a plurality of container covers comprising the steps of: forming a plurality of lid preforms having a plurality of ears on a peripheral edge of said lid, with a plurality of circumferential bases formed between each one of the ears; placing the preforms of the lid on a sheet of material in such a way that one or more of said ears of the lid preform intertwine with respect to the ears of an adjacent preform; cutting the preforms of the lid from a sheet of material; and forming a container lid with each of the preforms.

22. The method according to claim 21, with the placing step further comprising placing the preforms of the lid on a sheet of material deployed in two or more closely spaced rows, with the preforms of the cover in each row being in circular shape and having centers aligned; and each of the rows being diverted from an adjacent row.

23. The method according to claim 22, comprises the additional steps of providing an odd number of ears on each cap and forming the ears on each cap so that some have a different configuration than the others.

24. A container lid prepared by the method comprising the steps of: forming a plurality of lid preforms, each of the preforms comprising a flat surface having a plurality of ears on a peripheral edge of said surface, a plurality of circumferential bases formed between each of the ears, one or more of said ears comprising a male ear, and one or more of said circumferential bases having a complementary shape to correspond with said male ear; placing the preforms of the lid on a sheet of material such that each of the male ears of a preform are positioned within said circumferential base formed in complementarity with an adjacent lid preform; cutting the lid preforms placed from a sheet of material; and forming a container lid with each of the preforms.

25. The lid according to claim 24, further characterized in that said preform has a circular disc shape and an odd number of ears.

26. - The method according to claim 24, with the placing step further comprising placing the preforms of the lid on a sheet of material deployed in two or more closely spaced rows, with the lid preforms in each row having their centers aligned and each row being diverted from an adjacent row.

27. The cap according to claim 24, further characterized in that each preform has at least some ears that have a different shape to the other ears.