GB2140393A

GB2140393A - Cover to assist the wrapping of open egg containers and the like

Info

Publication number: GB2140393A
Application number: GB08413136A
Authority: GB
Inventors: Pietro Padovani
Original assignee: ISAP SpA
Current assignee: ISAP SpA
Priority date: 1983-05-24
Filing date: 1984-05-23
Publication date: 1984-11-28
Also published as: ES279399Y; SE8402766D0; DK249084A; NO842044L; PT78631B; CH661026A5; NL8401655A; PT78631A; LU85370A1; GB2140393B; ES279399U; FI842082A0; BE899737A; SE8402766L; IT8384939A0; FR2546486B1; DK249084D0; IT1175172B; FI842082A; GB8413136D0

Abstract

A thermoformed plastics cover to assist the film wrapping of an open egg container has an upper face (15) which is provided with frusto-conical depressions (17, 18, 19) and has outwardly flared side walls which incorporate channels, said channels and depressions being able to rest on projections of the container. Cavities (16) are provided which form anti-impact air cushions together with the wrapping film, and a continuous impact strip (21) is provided. <IMAGE>

Description

SPECIFICATION Cover to assist the wrapping of open egg containers and the like The invention relates to a cover of synthetic thermoplastics material which is preferably transparent and is designed to be applied to open egg containers made of wood pulp, board, expanded or rigid plastics material and the like. These containers which are designed to contain a certain number of eggs, e.g. 20, 24, 30, 36, are known as egg trays and consist of a given number of recesses separated by hollow frusto-conical or frusto-pyramidal projections with or without reinforcing ribs to take the eggs. These trays which are well known to those skilled in the art have projections along their sides which are frustoconical or frusto-pyramidal while the four corners of the containers have projections consisting of truncated conical or pyramidal projections.

These containers are provided with a cover of transparent synthetic plastics material in order that the eggs may be visible and in order to aid handling of the package, and are sold in a wrapped condition. When the package is wrapped with film known covers of flexible and transparent synthetic material have given rise to a series of problems, such as failure to seat prdperly on the container, bowing outwards of the lower parts of the side walls so that the edge of the cover breaks easily and the film is often punctured.

In the resulting packages it is often found that the tops of some of the eggs are in contact with the flat surface of the cover so that even slight pressure applied at these points results in breakage of the eggs.

In addition thereto, the stacking of empty covers results in the covers binding together, which makes it particularly difficult for the covers to be extracted mechanically for use in packaging operations of the type described.

It is an object of the invention to provide a cover which at least minimises the abovementioned disadvantages.

According to the present invention there is provided a cover to assist the film wrapping of open egg containers and the like made of wood pulp, board, foamed plastics or rigid plastics material obtained by the thermoforming of a thin sheet of synthetic material which is of a substantially frusto-pyramidal shape and has a substantially square upper face which is provided with frusto-conical depressions and has a side wall which incorporates channels each of which corresponds to a depression, the said channels and depressions being able respectively to rest on internal and peripheral projections of the container, in which cavities are provided which form an anti-impact air cushion together with the wrapping film, and a continuous impact strip designed to rest partly on peripheral projections, the said strip having at least one extension on either side of the cover which faces the interior of the cover and is connected to the upper face by means of a recess which is designed to project beyond the peripheral projections of the container while the lower part of the side wall is bent outwards and upwards to form a reinforcing channel with an outer edge and also in which the face has channels with bases, which constitute reinforcing ribs and from which spacers which are themselves known project inwards, at least along the side walls and in the vicinity of the four corners.

The present invention will be further illustrated, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a plan view of the cover from above; Fig. 2 is a side view of the same cover, partly in cross-section, taken along the line 22 of Fig. 1; Fig. 3 is a partial plan view of an alternative embodiment of the cover from above; Fig. 4 is a side view of the same cover, partly in cross-section, taken along the line 44 of Fig. 3; Figs. 5, 6, 7 and 8 are diagrammatical cross-sections of various types of cavity suitable for forming anti-impact air cushions with the film used in packaging; Fig. 9 is a partial plan view from above of a second alternative embodiment of the cover placed on a container beneath; Fig. 10 is a cross-sectional side view of the cover and the container beneath taken along the line 10-10 of Fig. 9;; Figs. 11 ,and 1 2 are two cross-sectional side views, similar to that of Fig. 10, of two alternative embodiments of the retaining recess in the cover; and Fig. 1 3 is a partial side view of the cover of Fig. 9 adjacent to a corner thereof.

As illustrated in Figs. 1 and 2, cover 14 is of a substantially frusto-pyramidal shape, the top face 1 5 thereof, which is substantially rectangular, being provided with frusto-conical cavities 1 6 which, together with the wrapping film form anti-impact air cushions between the top part of the egg supported in the tray, not shown, and the wrapping film.

It is clear that the frusto-conical cavity 1 6 can in practice be constructed to be any truncated pyramid without altering the essential characteristics of the invention.

Frusto-conical depressions 17, having inwardly tapering portions 1 8 which converge at base 19, are provided between the cavities 16 on face 15.

The side wall 20 of the cover 14 is provided with a continuous impact strip 21 at the level of the plane passing through the bases 1 9 so that, when the cover 1 4 is placed on the container, the bases 1 9 rest on projections of the container while the impact strip 21 rests on the peripheral projections thereof.

Channels correspondini to half the frusto-conical recesses 17, 18, 19, which with their bases 1 9 determine the extension of impact strip 21 toward the interior of the cover, are formed in the side wall of the cover. These extended portions are then connected to the top face 1 5 by means of walls having configurations and conical shapes corresponding to those of recesses 17, 18, 19.

Some of the said extensions of impact strip 21 are connected to the top face 1 5 of the cover 14 by means of frusto-pyramidal recesses 22 having side walls 23, but it is obvious that all the extensions or expansions of impact strip 21 may be connected in this way to the top face of the cover without altering the essential characteristics of the invention.

The said recesses 22, 23 are guide members which, in cooperation with side walls 20 of the cover overlying impact strip 21, ensure correct location of the cover 14 on the tray containing the eggs and at the same time the said recesses prevent any displacement of the cover during film wrapping of the package because they each bear against the side walls of the peripheral projections on the container.

These recesscs 22, 23 prevent outward bowing of the side wall 20 of the cover during film wrappini, being assisted in this by the edge which impact strip 21 forms with side wall 20 and the lower part of the side wall which is folded outwards and upwards to form a reinforcing channel 24 ending in an out-turned edge 25.

The upper part of the side wall 20 is connected in its straight sections to the top face 1 5 by means of bevelled edges 26, and it is clear that the sharp edges between the top face 1 5 and the recesses in the side wall 20 of the cover can be similarly bevelled so as to avoid puncturing the wrapping film even though this is not shown in the drawings.

The cover illustrated in Figs.3 and 4 differs from that described in relation to Figs. 1 and 2 in the fact that the part of the side wall 20 above the impact strip 21 has long straight sections provided with ribs 27 which extend parallel to the impact strip 21 and also wrap around the rounded edges thereof at the four corners of the cover.

In this example, the inward extensions of impact strip 21 are restricted to those connected to frusto-pyramidal recesses 22, 23 and the top part 1 5 of the cover, while reinforcing channels with a base 28 connect recesses 22, 23 to the frusto-conical depressions 17, 18, 19 facing them.

Similar reinforcing channels 28 with bases are also provided, for the purposes specified above, between depressions 1 7, 18, 1 9 at the four corners of the cover, in the direction of the larger and smallersides of the cover.

In addition, frusto-conical cavities 1 6 which bound the anti-impact air cushions together with the wrapping film are constructed with a frusto-conical projection 29 so that, in this case, the air cushion takes on an annular shape, as illustrated in detail in Fig. 6. The structure which shapes the air cushion in turn protects the tops of the eggs placed in the container from damage and, as a result thereof, the said cushion proves in practice to be more effective than the cushion which can be obtained with frusto-conical cavity 1 6 which is illustrated in detail in Fig. 5.

Fig. 7 illustrates an embodiment of the frusto-conical cavity 1 6 obtained using an annular projection 30 which projects from the plane of upper face 1 5 of the cover, while in Fig. 8 the frusto-conical cavity 1 6 in Fig. 5 is connected to the top face 1 5 of the cover with an annular ring 30 which is similar to that illustrated in Fig. 7.

The cover illustrated in Figs. 9 and 10 has an impact strip 21 which is wider than the corresponding strips in Figs. 1 to 4 in which it has been necessary to make spheroidal projections 31 so that the eggs 32 are correctly seated in the peripheral spaces of container 33, which is made of wood pulp, board or the like and is in itself known.

The said spheroidal projections 31 include a reduction in the width of impact strip 21 in the sections lying between the peripheral projections 34 of container 33 which is provided with a lamellar edge 35 which lies at a certain distance from both edge 25 and channel 24 of cover 1 4 which is placed on container 33 for subsequent film wrapping, as shown clearly in Figs. 10 to 12.

Hollow cylindrical spacers 36 project from the bases 28 of the reinforcing channels, see Figs. 9 and 10, and these prevent the covers from binding together when they are stacked.

As is known, spacers 36 are made using pairs of points in which one of the points is made to project in one pressing of the cover while the other point is made to project in the subsequent pressing so as to obtain supporting bases which are staggered in covers from two different pressings.

In Fig. 11 it will be seen that base 28 of the reinforcing channel connecting recess 22, 23 to a frusto-conical depression 1 7, 18, 1 9 is taken to the same base level as recesses 22, 23 to create a second cess with a base 28 which is similar to and separated from the aforementioned by a divider 38 which rests against the side wall of internal projection 37 close to peripheral projection 34, again with the object of preventing any displacement between cover 14 and container 33 during the film wrapping operation. In the embodiment illustrated in Fig. 12, divider 38 in Fig.

11 is not present with the result that the single recess 22, 23 is of sufficient dimensions to bear againstthe side walls of both peripheral projection 34 and internal projection 37 close to it with the same object of preventing any displacement between the cover 4 14 and the container 33 during the w;appi operation.

Claims

1. A cover to assist the film wrapping of open egg containers and the like made of wood pulp, board, foamed plastics or rigid plastics material obtained by the thermoforming of a thin sheet of synthetic material which is of a substantially frusto-pyramidal shape and has a substantially square upper face which is provided with frusto-conical depressions and has a side wall which incorporates channels each of which corresponds to a depression, the said channels and depressions being able respectively to rest on internal and peripheral projections of the container, in which cavities are provided which form an anti-impact air cushion together with the wrapping film, and a continuous impact strip designed to rest partly on peripheral projections, the said strip having at least one extension on either side of the cover which faces the interior of the cover and is connected to the upper face by means of a recess which is designed to project beyond the peripheral projections of the container while the lower part of the side wall is bent outwards and upwards to form a reinforcing channel with an outer edge and also in which the face has channels with bases, which constitute reinforcing ribs and from which spacers which are themselves known project inwards, at least along the side walls and in the vicinity of the four corners.

2. A cover as claimed in claim 1, in which each cavity is of frusto-conical shape and widens towards the face.

3. A cover as claimed in claim 1, in which each cavity is formed by means of an annular ring projecting from the face.

4. A cover as claimed in claim 2, in which each cavity is connected to the upper face by means of an annular projection.

5. A cover as claimed in claim 2, 3 or 4, in which each cavity has a central frusto-conical projection of a height equal to the depth of the cavity.

6. A cover as claimed in any preceding claim, in which the side wall above the strip is provided with ribs which extend parallel to the strip, at least in the vicinity of the four corners of the cover.

7. A cover as claimed in claim 1, in which the side wall above the strip is provided with spheroidal p,ojections.

8. A cover as claimed in claim 1, in which the channels with bases also include the channet of the wall of the depressions.

9. A cover as claimed in claim 1, in which the channels which have bases corsponding with the recesses form a second recess which is separated from the foregoing by means of a divider.

10. A cover as claimed in claim 1, in which the channels with bases corresponding to the recesses form a single recess with the latter between a projection and a projection of the container.

11. A cover as claimed in any preceding claim, in which the cover is formed of a transparent synthetic material.

1 2. A cover as claimed in claim 11, in which the transparent synthetic material is polystyrene or polyvinyl material.

1 3. A cover to assist the film wrapping of open egg containers and the like, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.