WO1991011370A1

WO1991011370A1 - A method of producing 'guarantee closed' packings, and a lid therefor

Info

Publication number: WO1991011370A1
Application number: PCT/DK1991/000027
Authority: WO
Inventors: Lars Gynther SØRENSEN
Original assignee: Soerensen Lars Gynther
Priority date: 1990-01-30
Filing date: 1991-01-30
Publication date: 1991-08-08
Also published as: AU7217191A; GB2256859A; GB9216084D0; GB2256859B; DK24290D0

Abstract

For obtaining a simple and efficient guarantee closure of jug shaped sales packings it is known to mount and crimp a piece of a plastic hose (18) about the edge of the mounted lid (4, 6) and a widened portion (22) of the jug (24) located just underneath the lid edge. However, the required equipment for mounting these sleeves (18) is so expensive that it can be used economically only in a large scale production. With the invention it is made possible to use the said closing also in smaller productions, because the said expensive equipment is utilized for a large scale production of lids (4, 6), which, placed on a carrier block (10), is separately provided with the sleeve (18), which is crimped at the outside and the top side of the lid, but not underneath the lid. For the jug closing in smaller productions it is then possible to use these prepared lids which can be mounted as usually and thereafter be guarantee closed just by a simple crimping treatment of the freely depending portion of the sleeve (18).

Description

A method of producing "guarantee closed" packings, and a lid therefor.

The present invention relates to a method of ef¬ fecting a so-called guarantee closing of jug shaped containers having a removable lid. A guarantee closing is an original closing, which, by its being opened the first time or by an advanced opening attempt, will pro¬ vide a visual marking of the lid having been opened entirely or just more or less. By way of example, a customer in a shop may then select a packing which has for sure not been opened since it left the station in which it was filled and then closed.

Different types of guarantee closures are known in the art, but only one o€ them should be considered here, viz. the widely used type comprising a piece of a plastic sheet hose crimped about the transition area between the jug and the lid, such that the sleeve is crimped into constrictions at both sides of this tran¬ sition area. The ring or sleeve of the crimp sheet mate¬ rial shall have to be ruptured for enabling the lid to be lifted, and such a rupture can easily be recognized from outside. The sleeve may well be prepared so as to be reasonably easily breakable, e.g. in being prepared with weakening lines which will enable an easy ruptur¬ ing, without the sleeve being easily ruptured uninten¬ tionally.

According to a commonly used method the sleeve is mounted by pulling a lower end portion of a suitably dimensioned sheet hose down over the top end of the newly closed packing, whereafter the hose is cut just above the lid and then exposed to a heat treatment, such that the said crimping occurs. This is a simple and safe method, which is also cheap, provided there are very large numbers of packings to be filled and handled. However, the method is less advantageous or economic by the handling of smaller numbers of units, because the required equipment for pulling down and cutting of the sheet hose is relatively expensive, i.e. it shall have to be used intensively.

It is the purpose of the invention to provide a method, by which it will be possible to make use of this type of guarantee closure in an economical manner even in enterprises that do not produce the units in par¬ ticularly large numbers.

The invention is based on the consideration that the more qualified or apparatus requiring part of the sealing operation is the said pulling down and cutting of the sheet hose and that this part of the operation ' can very well be effected under factory conditions prior to the filling and closing of the packings, viz. by pulling the hose down over the lid and then cutting it and fastening it to the lid, such that the lid is pro¬ vided with a skirt of a crimping sleeve; later on the lid and skirt unit can be placed on a jug with the skirt depending thereover, whereafter the skirt is fastened also to the jug by a suitable heat treatment or other crimping treatment. Hereby it will only be the latter, quite simple treatment that has to take place in the filling and closing plant, while the mounting of the sleeve skirt on the lid may take place in the lid pro¬ ducing factory or in a separate factory. What is impor¬ tant is that this factory will have a large, centralized production of lids with premounted skirts, independently of the numbers of lids used in the single users' enter¬ prises. Thus, the latter may enjoy that the 'crimping skirt lids' can be delivered as cheap standard products from a large production supplying these products to many users.

Typically, of course, it will be the jug supplier that will deliver both the jugs and the associated, now skirt carrying lids.

Theoretically the principle of the invention could be used in the manner that it is the jug manufacturer that provides the jugs with an upstanding skirt of a crimping sheet, which, after the filling of the jug and mounting of the lid, can be treated so as to crimp into holding engagement with the lid; such a method, however, would involve practical difficulties in connection with the filling of the jugs.

For the invention it is not decisive that the de¬ pending crimping skirt of the lid has been produced just as a cut, crimped piece of a sheet hose, when only it appears with the desired shape; this could well be pro¬ vided by rolling a sheet strip about the lid and con- ' necting the opposite ends by welding.

In the following the invention is described in more detail with reference to the drawing, in which:-

Fig. 1 is a perspective view of a jug lid being provided with a crimping skirt according to the inven¬ tion,

Fig. 2 is a cross sectional view thereof, and

Fig. 3 is a cross sectional view of the lid mounted on a sales jug.

The jug lid shown in Figs. 1 and 2 is designated 2 and is of a conventional shape having an upper lid plate 4 and lid skirt 6 depending therefrom; the upper corner area between these portions may be inclined as shown by a conical portion 8. The lid is shown placed on a car¬ rier block 10 which fills out at least the lower end of the lid and is in carrying engagement with the lid. The lid may have interior annular rib portions for holding engagement with corresponding holding portions on the jug which is to receive the lid later on, and the upper end of the block 10 should be designed with this in view.

In Fig. 1 it is shown that a sheet hose 12 is drawn down over the lid 2, down until the lower edge 14 of the hose is located somewhat underneath the lower edge of the lid, whereafter the hose is cut along the indicated line 16, slightly above the the top side of the lid. Thus, a sleeve member 18 will be left about the lid, extending somewhat both up- and downwardly therefrom, the diameter of the hose 12 being so adapted that the sleeve member 18 will be slightly tightened about the lid and thus be self holding thereon.

If the block 10 is supposed to be a jug having a lid 2 mounted after filling of the jug the operation here described will be well known. The sheet hose is made of a peripherally heat shrinkable material, and by a subsequent heating treatment the sleeve member will thus become radially crimped, whereby it is narrowed both above and below the outer transition area between the lid and the jug, whereby the desired guarantee clo¬ sure of the packing will be achieved.

Insofar as this technique is known, also the means for pulling down the sheet hose over the lid and subse¬ quently cutting the hose will be known, and these means, therefore, should not be described in more detail at this place. It is only to be emphasized that the produc¬ tion equipment is relatively expensive.

However, what is considered here is the use of ;the block 10 in stead of a jug, and the mounting of the sleeve 18 is effected as a lid production measure, that is under factory conditions, prior to the lids being delivered to the enterprises, in which they are to be used for closing the jugs after the filling of these.

When the sleeve 18 has been mounted as described its upper end portion is subjected to a heating treat¬ ment, illustrated by arrows in Fig. 2, whereby this upper end will crimp over the upper portion of the lid, as shown in full lines in Fig. 2. The part of the sleeve projecting below the bottom edge of the lid is not caused to crimp, and besides the block 10 would prevent a crimping of this sleeve part.

Thereafter the lid 2 with its associated sleeve skirt 20 is removed from the block, and this lid member or unit may then be piled with similar units for de¬ livery of such units to a number of user enterprises, the lids naturally being delivered together with cor¬ responding jugs. The skirt carrying lids can well be handled automatically in both the production factory and the users' enterprises.

In the user's enterprise the lids are put onto the filled jugs or corresponding containers and are mounted as usually, see Fig. 3, whereby the sheet skirt 20 on the lids will project underneath an upper widened por¬ tion 22 of the jug, which is designated 24 in Fig. 3. All what remains for producing the desired guarantee closure is to effect a heating of the skirt portion 20, such that the same will crimp into the position shown in dotted lines in Fig. 3. This operation can be accom¬ plished by means of a very simple and cheap equipment, that is for a small investment by the single enter¬ prises.

The sheet sleeve 18 could well be secured to the lid otherwise than by crimping, e.g. by adhesion or by welding, but it will be a normal customers' desire that the sleeve should be entirely removable once the packing is to be opened, and just by the crimping an advan¬ tageous combination of a safe holding of or to the lid and and easy removability from the lid is achievable. The sleeve may be prepared for an easy removal in a conventional manner, e.g in being provided with axially extending perforation lines 26, Fig. 1. It is known to shape the upper end of the jugs with a lateral depres¬ sion in the widening 22, such that at this place the sleeve skirt can be broken by pressing it into the de¬ pression, and this measure for facilitating the opening can be applied without further in connection with the invention.

The invention is not limited to the lid skirt being formed from a sheet hose, as it might be formed from a strip material that is connected with the lid in being wound therearound and joined in any suitable manner.

Claims

C L A I M S :

1. A method of establishing a guarantee closing of jug shaped packings having a removable lid, by mounting a crimpable sheet sleeve about the transition area be¬ tween the jug and the lid, said sleeve being subjected to a crimping treatment after the mounting of the lid such that the sleeve will thereafter appear as narrowed about both an upper part of the lid and an underlying narrowed portion of the jug just underneath the mounting area of the lid, characterized in that in a first step the sleeve is mounted about either the edge of the lid or the upper edge of the jug, before these parts being brought together, depending from the lid or upstanding from the jug edge, respectively, the sleeve initially being caused to crimp selectively about the respective upper edge of the lid or a lower edge of the jug, such that the lid is ountable on the jug without hindrance from the respective downwardly or upwardly projecting skirt portion of the sleeve, while just that portion upon the mounting of the lid is subjected to a crimping treatment, by which it is narrowed for engagement with the lower edge of the widening adjacent the upper jug end or, respectively, the upper edge of the outer edge area of the lid.

2. A method according to claim 1, characterized in that for the closing of a series of jugs use is made of a corresponding series of lids that are premounted with the depending sleeve.

3. A lid for mounting on a jug by the method ac¬ cording to claim, 1, characterized in that it is pro¬ vided with a premounted, crimpable sheet sleeve en¬ circling the edge of the lid and depending therefrom, this sleeve being treated for local tight crimping about the lid, while the depending sleeve portion assumes a noncrimped or only slightly crimped condition.