AU604016B2

AU604016B2 - Heat printed carrier and method

Info

Publication number: AU604016B2
Application number: AU72921/87A
Authority: AU
Inventors: Lorne Bonkowski Ph.D
Original assignee: Bonkowski Lorne
Current assignee: Bonkowski Lorne
Priority date: 1984-04-19
Filing date: 1987-05-14
Publication date: 1990-12-06
Anticipated expiration: 2007-05-14
Also published as: US4688367A; AU7292187A

Description

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FORM 10 60 SP US IR ON COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE: Class Int. Class Complete Specification Lodged: Accepted: Published: 7 q2/ b7 Priority: Related Art: t Name of Applicant: Address of Applicant: Actual Inventor: Address for Service: LORNE BONKOWSKI This document contains the amendments made under ectio1n 49 and is correct for printing 1219 Paloma, Stockton, California 95209 United States of America LORNE BONKOWSKI Spruson Ferguson, Patent Attorneys, Level 33 St Martins Tower, 31 Market Street, Sydney, New South Wales, 2000, Australia 6r SComplete Specification for the invention entitled: "HEAT PRINTED CARRIER AND METHOD" The following statement is a full description of this invention, including the best method of performing it known to me/u-e 1 PD-6968 HEAT PRINTED CARRIER AND METHOD BACKGROUND OF THE INVENTION: 1. Field of the Invention This invention relates to the covering or cealing of one or more articles, and especially to multi-pack carriers for an array of containers, such as the common six-pack beverage can container.

2. Prior Art It is well known to connect an array of articles tC by means of a plastic carrier in order to package them as a single unit. There are many packages of this general type, representative carriers and packaging machines being disclosed by Poupitch in U.S. Patent Nos. 2,874,835, 2,929,181 and 2,936,070, by Hall et al.

in U.S. Patent No. 3,032,944, by Fisher in U.S.

Patent No. 3,044,230, by Dreyfus in U.S. Patent No.

3,744,626, by Curry et al. in U.S. Patent Nos.

3,134,485 and 3,206,019, and by Bonkowski in U.S.

Patent No. 4,281,502. In addition, carriers which S Df incorporate a cover of some type over the containers are disclosed by Harrison in U.S. Patent No. 3,046,711, by Rapata in U.S. Patent No. 3,200,944, by Poupitch in U.S. Patent No. 3,355,013, by Hatfield in U.S. Patent No. 3,871,699, and by Curry et al. in U.S. Patent No.

4,116,331. Most of these carriers include either a first carrier layer, and a second cover layer or require the presence of a bead on the rims of the containers, or both.

V As the foregoing patents evidence, simple and effective seals and carriers for containers have long been sought. Today, such seals or closures often take the form of a cap threaded about the top of the container, or crimped about the rim of the container.

To prevent tampering with the contents, often such containers include one or more additional seals such as an adhesively secured disc beneath the cap and covering the mouth of the container. In high volume packaging i 11 ;r UJ- U to

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4 :4 a 4 4 I I S I I I 4 4 51 applications, such caps must be applied at a rapid rate, and such seals al.so must be applied at a rapid rate. The machinery for doing this Iz complex, expensive, and requires constant and substantial maintenance to function properly. Also, such closures represent a significant portion of the total cost of the package.

Often containers are packaged in arrays and held together by various forms of carriers, one of which is the common 6-pack caf-rier, a stretchable plastic sheet with six openings for receiving the tops of the containers and engaging the underside of the rim &bout the tops to hold the containers in an array. Such carriers also are difficult to apply, and require expensive machinery thpt needs constant attention to function properly. Further, the carriers, when used and discarded, represent a significant threat both to the enviroimevxt and to wildlife. Also, such carriers fail to seal or otherwise cover the tops of the containers and thus permit their contamination. There is a growing need and desire for such carriers that are easily applied by simple machinery, that are inexpensive, and that also cover and seal the top portions of the containers in the array.

it is an object of the prmsent invention to provide a simple one-piece closely fitting cover or sealant for an article. The pharmaceutical industry is an example of one area in which manufacturers have become aware of the need for providing a simple, economical means of effectively sealing their products in order to prevewit outside tampering. As instances of tampering become more widespread, other ;manufacturers who package products for 'human consumption will also require a simple method for sealing their products.

The present ,invention provides such a method.

I t 1-'_another object of the present invention to provide a carrier which does not require a bead or .1 1~.

-3- It Is the object of the present invention to overcome or substantially ameliorate the problems and/or disadvantages of the prior art.

In one broad form the present Invention provides a method of forming a cover for at least one article, said article having a top surface and a side wall surface, the cover comprising a sheet of material which is stretchable when softened but otherwise relatively rigid, the method comprising the steps of: Softening a portion of said sheet, the softened portion being of a shape other than the same shape as the top surface or of a size other than S0 and slightly larger than the size of the top surface, the softening step leaving a nonsoftened portion of said sheet around said softened portion; o 00 Forming the nonsoftened portion of said sheet around said side wall °o surface sufficiently to cause the softened portion of the sheet to stretch and conform about the article thereby forming a closely fitting cover.

A further broad form of the present Invention provides a machine for forming a cover for at least one article, the article having a top surface and a side wall surface, wherein the cover is formed from a sheet of material which is stretchable upon being softened by application of heat but which is otherwise relatively rigid, comprising: Means for softening a portion of the sheet, the softened portion being of a shape other than the same shape as the top surface or of a size other than and slightly larger than the size of the top surface, the softening means leaving a nonsoftened portion of the sheet around said softened portion, and Means for forming the nonsoftened portion of the sheet down about the side wall surface of the article, thereby causing the softened portion to stretch and be drawn over and about the article to form closely fitting cover.

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4 A still further broad form of the present invention provides a cover for at least one article, the cover being formed of a material which can be rendered pliable and stretchable, then later rendered relatively rigid and non-stretchable, the cover closely conforming about the top portion of the article and being in a relatively rigid, non-stretchable condition, the cover incorporating areas adjacent to the article of substantially different thicknesses.

Preferred forms of the present invention will now be described by way of example with reference to the accompaiying drawings, wherein: 1 H K N11567b BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further described in connection with the accompanying drawings in which: FIGURE 1 is a perspective view of an array of containers interconnected by a carrier formed in accordance with the present invention; FIGURE 2 is a perspective view of a container showing a plastic sheet positioned above the container, with the portion of the sheet to be pulled over the top \c of the container in a softened state, and a foriming plate having a different shape than that of the container to be covered positioned over the plastic sheet; FIGURE 3 is a perspective view of a covered container in which the heated portion of the plastic was a different shape than the top of the container to be covered; FIGURES 4a and 4b are top and perspective views, respectively, of a container with a pull-top type seal O formed in accordance with the present invention; FIGURE 5 is a plan view of a machine which may be used to make the carrier; and FIGURE 6 is a perspective view of a component of the machine shown in Fig.

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,rtiie -ij 1. i u pn-QR68 DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention may be used to cover, seal, hold or protect a single article. It may also be employed to interconnect a series of articles. The method disclosed allows the sealing or covering process to be broken down into several distinct steps. There is no requirement that the heating and forming processes be performed in an area adjacent to the articles to be covered, or that any particular type of covering material be used it only need be capable of being softened by heat, chemical, or other softening means, and of being restiffened upon recooling or other conditions. Many different types of carriers or seals may be formed by varying the shape of the heat imprinted portion of the covering material. The embodiments of the carrier herein set forth are merely illustrative of the invention and the principles it employs. While it is described in many of the embodiments as being applied to a 3eries of containers, such as beverage containers, it may be applied to any of a wide variety of other articles, and for any of various applications or purposes, only some of which are mentioned herein.

The present invention differs from the carriers and methods disclosed in the aforementioned patents in several significant respects. For example, when compared with the Bonkowski patent, supra, the present invention can employ a contact heating method rather than being limited to radiant heat through a patterned insulating plate. Thus, in the new method and machine, the insulating plate is done away with; the softening of the plastic covering material is accomplished by imprinting a heat pattern directly onto the plastic itself. Further, the new method does not require that the heating process take place at a location immediately adjacent the article to be covered; the softening process may take place at a location

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_1 1. -i I; 7. PD-6968 substantially separated from the forming process. One of the most important differences between the present invention and the approach set forth in the Bonkowski patent, supra, is that the forming plate need not correspond in absolute or even relative shape to the portion of the article to be covered. Likewise, the shape of the softened area need not conform in shape or size to the top of the article to be covered. By varying the shape of the heat imprinted area, it is i0 possible to create, for example, tabs or other easyopen type seals. These two improvements serve to significantly simplify the covering process and the machine required to do such covering. For instance, with only a slight modification to the heat patterning elements, the same machine could be used to create covers as various as: tamper-evident seals with pull tabs, inner cap seals, carriers, shipping packages or display packages.

Referring to FIGURE 1, a carrier 10 is shown interconnecting an array of six containers 12. The carrier 10 includes a side portion 14 which surrounds the upper part of the wall of each container 12 in the array. Each side portion 14 may consist of a ridged or serrated area 16 at its base, and a cover portion 18 located over the top of each container 12. A skirt portion 20 extends from the bottom of the side portions 14, the common skirt portion interconnecting the containers 12 and providing a carrier for the array.

FIGURES 2 and 3 illustrate a preferred method for 2 sealing a single article. The disclosed method and invention are equally well suited to covering an array of articles. As shown in FIGURE 2, a sheet of material 22 is positioned over the article 24 to be covered.

This sheet may be of any material that can be softened, such as upon application of heat, and can then be returned to a relatively stiff or rigid condition, such as upon cooling. For example, a thermosensitive -t -8plastic, such as polyethylene, may be used to form the sheet, j The following examples assume use of such a thermosensitive material. Other materials likely will require a somewhat different approach, yet may proceed in accordance with the teachings set forth herein.

A heated platen 26 is used to soften a selected portion of the material 22. This softened area may or may not conform to the shape of the top of the article 24 to be covered, depending on the desired configuration of the resultant ccver. The softened portion 28 is then positioned over the article 24 to be covered. Located above the covering material 22 is a forming plate 30 which has an opening 32 in its middle. This opening also need not conform to the shape of the top of the article 24 to be covered or evon to the shape of the softened area; a square opening is shown for illustrative purposes. The opening 32 of the illustrated embodiment is substantially larger than the softened portion 28 or the top of the article 24 to be covered. When the exposed portion of the sheet 22 has been softened to an extent adequate to render it reasonably pliable or stretchable, the forming plate 30 is then lowered to move the sheet down over the top of article 24 and form the material 22 over the top of the article 24.

As the forming plate 30 moves downward, it engages the nonsoftened portion of the sheet 22, which causes the softened portion 28 of the material to stretch and form around the top of the article 24. The forming plate 30 is then lifted and removed.

By these simple steps, and as shown in Figure 3, sheet 22 has been formed into a seal or cap which covers the top of the article 24 and a portion of its side 34. Due to the serrated or irregular margin of circular heated portion 28, resulting from the pattern of heat applied by platen 26, the cover contains a ridged portion 35 around the sides of the article 24. Such a portion can, for example, assist in holding the article to sheet 22. After forming the sheet 22 over the top of the article 24, the sheet 22 is allowed to cool thereby returning the heated portion 28 to its SBR:eah 39T _i 9. PD-6968 previously stiff or rigid state. When the sheet 22 has returned to its original unsoftened state, the process is completed and an effective one piece carrier or cover is provided in a simple, effective manner.

It is not necessary that the article to be covered contain any type of bead or rim about its top in order to effectuate a tight, durable seal. In addition, the method may be used to cover an article or articles of virtually any shape or size. One potentially very useful application of the method is shown in FIGURES 4A and 4B. By heating a portion 36 of the covering material, as shown in FIGURE 4A, while selectively leaving an unheated tab portion 38, a pull-top type cover may be produced. After the material has been heated, as in FIGURE 4A, the forming process previously described in FIGURES 2 and 3 is then used to conform the heated material to the top of the article 40 to be covered. The result in FIGURE 4B is a seal which contains a thick rim and tab portion 38, and a thinner cover over the top of the article. The portion 38 thus a provides a pull top tab which allows the seal to be easi.ly pulled off by applying an upward pressure to the tab 38. By varying the shapes of the heated surfaces, different types of tamper-proof and pull-top type seals may be easily produced, the relative thickness of portions 36 and 38 may be adjusted.

As some examples of other applications, the design of the softened area might be adjukted to result in a *44 4 0cover with added strength (due to increased thickness) in selected areas, or with ultrathin areas to readily fracture if the cover were disturbed. Also, such covers may be applied over sharp edges, or about threaded areas, or upon articles with irregular shapes and configurations. Caps and other structures can be applied over such covers if desired. Selected perforations can be provided in the cover for various purposes, such as to facilitate removal of the article PD-6968 from the carrier, or the cover from the article, or to f permit interior pressure to be released. In short, the present method and cover offers exceedingly great flexibility in its uses and applications. The foregoing only suggest some of such uses and applications; many others will be readily apparent to those skilled in this field.

In FIGURE 5, the major elements of a machine are shown; the machine being used to rapidly seal a number of articles employing the previously described method.

A line of articles 42 are brought to the machine by a simple transfer conveyor 43 of conventional design.

The articles are transferred to a special in-feed conveyor 44 which contain3 gaps or holes to allow for an indexing mechanism 46 to engage and position the articles 42 in a manner which will align them with the softened areas of the plastic material and with the forming device. The plastic covering material 48 is fed to the machine from a supply roll 50. The material S48 enters the heating station or segment of the machine 52 where areas of the material 48 are selectively brought to forming temperature through contact with temperature controlled platens 54 on opposing belts.

The material then passes over the articles or objects 42 and under the forming device 56 (shown in perspective in Fig. As the .forming device rolls over the aticles 42, it presses sheet 48 down about the articles and the softened areas stretch over the top portions, thereby forming the sheet into a cover or carrier. The forming device 56 consists of a cylindrical wheel with elliptical shaped openings 58.

Of course, if multiple lines of adjacent articles are to be simultaneously covered, forming device 56 would include multiple circumferential bands having openings 58. After the objects leave the forming section of the machine, they are held in a continuous web provided by material 48. The packages can then be divided into 11. PD-6968 i appropriate multiples, as desired, using conventional, well-known mechanisms.

In summary, the present invention provides a simple, econbmical method for creating seals and covers as well as carriers for a single article or a group of articles. The method disclosed allows great latitude in the design of the particular seal, cover and machine since the softened area can have virtually any shape and since the softening process need not be carried out (0 in proximity to the articles to be covered, and the forming device need not conform to the shapes of the tops of the articles to be covered. Variations in the disclosed covers, structures and methods will be apparent to those skilled in this art from the teachings presented herein. Accordingly, the scope of the invention is defined by the following claims.

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Claims

1. A method of forming a cover for at least one article, the article having a top surface and a side wall surface, the cover comprising a sheet of material which is stretchable when softened but otherwise relatively rigid, the method utilizing a forming element which defines an opening substantially larger than the top surfere of the article, the method comprising the steps of: softening a well-defined, predetermined portion of said shept, the softened portion being other than the same shape as the top surface and being other than slightly larger than the size of the top surface, and further being substantially smaller than the size of the forming element opening, the softening step leaving a nonsoftened portion of said sheet around said softened portion; and 2ngaging the nonsoftened portion of said sheet with said forming element wherein the softened portion of the sheet is within the forming element opening, said forming element engaging the nonsoftened portion sufficiently to thereby cause the softened portion of the sheet to stretch and conform about the article thereby forming a closely fitting cover; wherein the forming force exerted on the softened portion Is transmitted from the forming element by the nonsoftened portion.

2. A mnthod of forming a cover for at least one article as set forth in claim 1 in which the softened portion is smaller in area than the top surface area of said article.

3. A method of forming a cover for at least one article as set forth in claim 1 in which the softened portion is equal In area to the top surface area of said article,

4. A method of forming a cover as set forth in claim I In which the softened portion includes at least one unsoftened portion projecting into the soFtened portion and providing a relatively rigid, stiff tab portion adjacent the article. A method of forming a cover as set forth in claim 1 In which the sheet is softened at a first location, then, at a second location, forced over the top surface of the article.

6. A method of forming a cover for a plurality of articles as set forth in claim 1 In which a plurality of separate portions of the sheet are softened, the sheet then being forced about a plurality of articles, each rhk/021 9E 13 i softened portion of the sheet stretching and conforming about the top surface and a portion of the side wall surface of one article, thereby forming an assembly of closely fitting covers for a plurality of articles.

7. A method of forming a cover as set forth In claim 7 In which the sheet Is sufficiently stiff and rigid, relative to the weight of the articles, to permit the sheet to be used as a carrier or package for the articles.

8. A method of forming a cover as set forth in claim 8 In which the sheet is softened at the first location and forced about the plurality of articles at a second location. 9, A machine for forming a cover for at least one article, the o article having a top surface and a side wall surface, wherein, the cover Is .O formed from a sheet of materia' which Is stretchable upon being softened by application of heat but which Is otherwise relatively rigid, comprising: means for softening a portion of the sheet, the softened portion being of a shape other than the same shape as the top surface and of a size other than slightly larger than the size of the top surface, the softening means leaving a nonsoftened portion of the sheet around said softened portion; and means including a forming element defining an opening substantially larger than the top surface for forcing the nonsoftened portion of the sheet down about the side wall surface of the article, i ithereby causing the softened portion to stretch and be drawn over and about the article to form a closel:; fitting cover. A machine as set forth In claim 9 In which the sheet Is softened by a heated platen In the shape and size of the portion of the sheet desired to be softened the platen being moved to a position adjacent to i the sheet to heat print the sheet and soften the desired portion of the sheet, |i h11. A machine as set forth in claim 10 in which the softened portion Sis smaller in area than the top surface area of the article.

12. A machine as set forth in claim 10 in which the softened portion is equal In area to the top surface area of the article,

13. A machine as set forth in claim 10 In which the shape of the softened portion Is different than the shape of the top surface of the article, rhk/O219E 14

14. A machine as set forth in claim 10 in which the means for forcing the nonsoftened portion of the sheet down about the article includes an opening of a shape different than the shape of the top surface of the article. A machine as set forth in claim 10 in which the softened area includes at least one unsoftened portion projecting into the softened area and providing a relatively rigid, stiff area of the cover lying alongside the surface of the article.

16. A cover for an article, said cover being formed by the method set forth in claim 1.

17. A cover for an article, said cover being formed by the method set forth in claim

18. A cover for a plurality of articles, the cover being formed by the method set forth in claim 6.

19. A cover for a plurality of articles, the cover being formed by the method set forth in claim 8. A cover as set forth in claim 22 in which the margin between the thin and thick portions of the cover defines a shape different than the shape of the covered portion of the article.

21. A method of forming a cover for at least one article, said article having a top surface and a side wall surface, the cover comprising a sheet of material which is stretchable when softened but otherwise relatively rigid, the method utilizing a forming element which defines an opening substantially larger than the top surface of the article, the method comprising the steps of: softening a well-defined, predetermined portion of said sheet, the softened portion being smaller than the size of the top surface, and further being substantially smaller than the size of the forming element opening, the softening step leaving a nonsoftening portion of said sheet around said softened portion; and engaging the nonsoftened portion of said sheet with said forming element wherein the softened portion of the sheet is within the forming element opening, said forming element engaging the nonsoftened portion sufficiently to thereby cause the softened portion of the sheet to stretch and conform about the article thereby forming a closely fitting cover; wherein the forming force exerted on the softened portion is Stransmitted from the forming element by the nonsoftened portion, rhk/0219E i 15

22. A cover for at least one article as hereinbefore described with reference to, and as shown in the accompanying drawings.

23. A machine for forming a cover for at least one article as hereinbefore described with reference to, and as shown in the accompanying drawings.

24. A cover for-aT-Teast one article as he e'S-7n -db-b el reference tda,r-and-as-showtn_ eiaccopyn dawings. 24-. A method of forming a cover for at least one article, said article having a top surface and a side wall surface, the cover comprising a sheet of material which is stretchable when softened but otherwise relatively rigid, the method utilizing a forming element which defines an opening substantially larger than the top surface of the article, the o method comprising the steps of: softening a well-defined predetermined portion of said sheet, the softened portion being the same size as the top surface, and further being substantially smaller than the size of the forming element opening, the softening step leaving a nonsoftened portion of said sheet around said S softened portion; and Oo engaging the nonsoftened portion of said sheet with said forming element wherein the softened portion of the sheet is within the forming o element opening, said forming element engaging the nonsoftened portion sufficiently to thereby cause the softened portion of the sheet to stretch and conform about the article thereby forming a closely fitting cover; wherein the forming force exerted on the softened portion is transmitted from the forming element by the nonsoftened portion. DATED this ELEVENTH day of SEPTEMBER 1990 Lorne Bonkowskl i" Patent Attorneys for the Applicant SPRUSON FERGUSON rhk/0219E