GB2360760A - Sleeve for receiving a tray - Google Patents

Abstract

A sleeve is constructed from a cut and creased sheet material blank having a plurality of panels (4, 10, 14, 18, 22, 26) therein defined between crease lines. The sleeve is formed by adhering a first panel (4) defined between a free edge (6) and a first crease line (8) to a last panel (26) defined between the opposite free edge (28) and a last crease line (24) to define the sleeve construction with a pair of open ends through either of which a tray can be inserted. The first panel (4) is adhered underneath the last panel (26) well behind the free edge of the last panel (26) so that the first crease line (8) is concealed behind the last panel (26) when the sleeve is erected. Remaining crease lines define the vertices of the sleeve and provide its characteristic shape. The free edge (28) may have an arcuate or other non-straight profile. The crease lines are arranged to allow the sleeve to be folded flat.

Description

2360760 Carton This invention -relates to an improved carton, and

particularly to an improved sleeve-type carton which has at least one and ideally two open ends to enable a tray containing consumable produce to be slid into the sleeve through one or other of said ends.

Although the following description is exclusively concerned with the packaging of food products and consumables in general, it will be instantly understood that the sleeve-type cartons described hereinafter may be used to package any type of product which is commonly provided in plastics, metal foil or polymer material trays which once formed do lend themselves easily to machine handling on account of their shape or cannot easily and rapidly be printed with suitable information concerning the contents of the particular tray. Also, in many cases trays containing perishable food products are often provided as an open-topped receptacle over which is subsequently applied a polymer film seal which is thermally attached around its edges to an upper flange provided around the peripheral upper edge of the tray. The printing of such films with conventional printing inks is difficult and costly, especially after the film has been applied to the tray and the food packaging industry has thus opted to provide such trays within sleeve-type cartons which are formed of a board or card material which is readily printable.

In recent times there has been a consumer tendency towards pre packed and partially pre-cooked food products which can be easily packaged in trays and cooked by the consumer without the need to remove the food product from the trays. Foods packaged in this manner can be quickly prepared for consumption in microwave and conventional ovens, whereafter the tray and the sleeve-type carton covering same can be easily disposed of. The vast majority of the trays used in the packing of such foodstuffs are of a rectangular 2 cross-section which tapers from the upper open top of the tray to the base, the uppermost periphery of the carton being provided with a flange to which a polymer film can be applied to seal the carton and having inwardly slanting walls which reduce the cross-sectional area of the carton over its depth to the base. The invention is equally applicable to non-recto angular containers such as round or oval tubs with film seal or separate lid closure.

Although the provision of such a tray does not necessitate a sleeve type carton having a pair of inclined walls which connect the top surface of the sleeve to its base, aesthetic considerations and the amount of material required to manufacture each sleeve have resulted in the provision of sleeves having a cross-section in the shape of a trapezium when viewed from either of their open ends.

The disadvantage of such a sleeve is that it while they can be readily manufactured from a cut and creased sheet material blank by adhering one free edge to an oppositely disposed free edge to form a tubular sleeve construction, there is a requirement to provide a fifth crease line proximate one of the four standard crease lines which ultimately form the vertices of the sleeve once erected to enable the sleeve to assume a flat condition. This is essential where the sleeves are to be transported from the carton manufacturer and/or printer to the food packaging plant in flattened tubular form.

The important different between a sleeve or carton having a rectangular cross-section and one having a trapezium cross-section is that the inclination of the walls in the latter type towards each other prevents the upper surface and the base of the sleeve from being sheared relative to one another such that sleeve assumeds a flat condition. Regardless of the direction of the relative shearing, a sleeve having an irregular quadrilateral crosssectional shape results.

3 Either a fifth crease line is required, or two additional crease lines provided at the same depth in the opposite walls so that as the sleeve is flattened, the inclined walls can fold about the additional crease lines and the upper surface of the sleeve can be moved towards the base without any relative shear between same.

In any event the provision of the fifth or additional crease lines is detrimental to the aesthetic appearance of the sleeve, which in many cases is in many cases only loosely fitted over the tray which it conceals.

It is an object of this invention to provide a sleevetype carton having a pair of open ends from either of which a tray can be inserted and which can be constrained to assume a flat condition wherein the provision of a fifth or additional crease lines does not affect the aesthetic appearance of or interrupt the continuity of the side walls of the sleeve.

According to the invention there is provided a sleeve constructed from a cut and creased sheet material blank having a plurality of panels therein defined between the crease lines and the opposite free edges of the blank which are substantially parallel therewith, said sleeve being formed by adhering a first panel defined between a free edge and a first crease line to a last panel defined between the opposite free edge and a last crease line to define the sleeve construction with a pair of open ends through either of which a tray can be inserted, characterised in that the first panel is adhered underneath the last panel inwardly of the opposite free edge which thus conceals the first crease line with the remaining crease lines defining the vertices of the sleeve.

4 In accordance with a second aspect of the invention there is provided a sleeve construction as described in combination with a tray inserted within the sleeve which constrains said sleeve to adopt its fully erected condition.

Preferably the sleeve with tray concealed therein has a trapezium crosssectional shape when viewed from either of the open ends.

Preferably the blank from which the sleeve is constructed has six panels, the first panel being defined between a first free edge and a first crease line, a second panel being defined between the first crease line and a second crease line, a third panel being defined between the second crease line and a third crease line, a fourth panel being defined between the third crease line and a fourth crease line, a fifth panel being defined between the fourth crease line and the last crease line, and the last panel being defined between the last crease line and the opposite free edge of the blank.

Preferably the second panel serves as an extension to the third panel and becomes parallel therewith as the sleeve is constrained to assume its flattened condition by relatively shearing the last panel with respect to the fourth panel.

Preferably the fourth panel is substantially the same cross-sectional shape and area as the base of the tray which the sleeve is adapted to contain.

Preferably the last panel is substantially the same cross-sectional area and shape as the tray which it is adapted to contain in a plane parallel and contiguous with the uppermost edge of said tray.

Preferably the said opposite free edge which defines the last panel together with the last crease is straight, and most preferably the first panel is adhered underneath said last panel in a location which results in the coincidence of the said opposite free edge with the second crease line after insertion of the tray within the sleeve.

Alternatively, it is preferable that the said opposite edge- is arcuate at least over some of its length to define one or more flap portions which can be printed with promotional or like information, or can serve to increase the aesthetic appearance of the sleeve.

Preferably said opposite free edge is arcuate over at least some of its length and the first panel is adhered underneath the said last panel in a location which results some aesthetic interplay between the said arcuate opposite free edge and the first crease being which is at least partially visible underneath said free edge when the sleeve is in its erect condition.

Preferably the one or more flap portions are provided with one or more lines of perforations on at least one side thereof which extend into the last panel such that said flap portions can pulled by a user to initiate tearing of the said perforations to facilitate the opening of the sleeve.

The understanding of the invention will be further enhanced with reference to the following specific embodiment which is provided by way of example only in connection with the following figures:

Figure 1 shows a perspective view of a sleeve carton according to the invention, Figure 2 shows a perspective view of the sleeve of Figure 1 in partially flattened form, 6 Figure 3 shows the sleeve of Figures 1 and 2 in its fully flattened condition, and Figures 4, 5, 6, 7 show various different configurations of carton blank which can be used in the formation of sleeve-type cartons according to the invention.

Referring firstly to Figure 1 there is shown an erected sleeve-type carton 2 adapted to receive a conventional tray (not shown) commonly used to contain perishable or frozen foodstuffs. The sleeve 2 is provided with a plurality, of panels, the first 4 of which is defined bs, the first free edge 6 and a first crease line 8, the second 10 being in the same plane as the first panel when the sleeve is in its fully erected condition as it would be when concealing a tray. The second panel 10 is defined between the first crease line 8 and a second crease line 12, the third panel 14 is defined between the second crease line 12 and a third crease line 16, the fourth panel 18 is defined between the third crease line 16 and a fourth crease line 20, the fifth panel 221s defined between the fourth crease line 20 and a last crease line 24, and the sixth and last panel 26 is defined between the last crease line 24 and an arcuate free edge 28 of the sleeve. Although the free edge 28 is shown as arcuate in Figure 1, it will be appreciated that any desired edge profile may be considered, and for example an angular and/or oblong edge profile may be chosen.

As can be seen from the figure, the first panel 4 is ideally secured underneath the last panel 26 such that the first crease 8 line is concealed underneath said last panel 26 and is invisible when the sleeve is in its fully erected condition. ln an economy version of the sleeve, the edge 28 need only extend a fractional distance beyond the crease line 8 so as to conceal same when the sleeve is erected, the arcuate profile of the said edge being optional.

7 The remaining crease lines 12, 16, 20, 24 form the vertices of the sleeve and provide the sleeve with its trapezium cross-sectional shape when viewed from either of its open ends, one of which is referenced at 30. The position in which the first panel 4 is adhered to the underside of panel 26 is important for two reasons. Firstly, the sleeve is symmetrical about a vertical axis passing through the mid point of lateral edges 32, 34, and secondly the second crease line which forms the first vertex of the sleeve is at least partially obscured by flap portions 36, 38 defined in the last panel 26 by the arcuate edge 28. The said second crease line is visible when not so obscured, and it is this interplay between the said arcuate edge and the second crease line which provides the carton with its enhanced aesthetic appearance.

Furthermore, said flap portions may be printed with promotional, advertising or product characteristic information (such as for example the products suitability for vegetarians), and thus the customer recognition of particular products contained within the tray concealed by the sleeve is improved.

Ideally the last panel 26 will form the uppermost surface of the sleeve, third and fifth panels 14, 22 form the inclined side walls, and the fourth panel defines the base of the sleeve.

The tray containing the food products may be slid into the erected sleeve through either open end, and the combination of the sleeve thus formed together with the tray concealed thereby forms an independently claimable aspect of the invention. It is important to note that the sleeve will be most usually designed according to the particular dimensions of the tray it is to conceal, and therefore when the tray is slid into the sleeve, said tray provides support for the sleeve which, being made of carton board, may have a tendency 8 to elastically recover to its flattened condition. Furthermore the tray maintains the sleeve in its erected condition.

Figures 2 and 3 demonstrate how the sleeve of Figure 1 may be progressively flattened into a flat condition as shown in Figure 3. In particular in these figures it can be seen how the second panel forms an extension to the third panel 14 as the sleeve is flattened until both of said panels lie substantially in the same plane when the sleeve is substantiall, flat. The second panel 14 rotates during the flattening about the concealed first crease line 8 whereas in the prior art configuration said crease line would usually interrupt the continuity of one of the side walls or the base of the sleeve.

Figure 4 shows a typical carton blank from which the sleeve of Figures 13 could be manufactured.

Other examples of carton blank are shown in Figures 5, 6, and 7. The blanks shown in these figures are erected in exactly the same manner as that shown in Figure 4 (and therefore like reference numerals have been used to identify like features), and are furthermore provided with the same number of panels having similar widths so that a sleeve having a trapezium cross-sectional shape is formed when the respective first panels 4 are adhered inwardly of the free edges 28 such that the first crease line 8 is concealed when the sleeve is fully erected and view from above the panel 26.

In Figure 6, the free edge 28 is partially arcuate at 50, and partially straight at 52 such that only a single flap portion is defined in the erected sleeve. In Figure 7, the third and fifth panels 14, 22 have tapers along there lateral edges and the fourth panel 18 is of reduced height as compared with the panel 26. The reduction in material achieved results in a more economical sleeve which merely 9 tapers not only as its depth increases by virtue of the trapezium cross- sectional shape but also laterally. The functionality of the sleeve is riot compromised by such a taper-it merely conforms more closely to the shape of the tray which is concealed within the sleeve, as conventional trays do taper in both of these directions.

Claims (12)

1. A sleeve constructed from a cut and creased sheet material blank having a plurality of panels therein defined between the crease lines and the opposite free edges of the blank which are substantially parallel therewith, said sleeve being formed by adhering a first panel defined between a free edge and a first crease line to a last panel defined between the opposite free edge and a last crease line to define the sleeve construction with a pair of open ends through either of which a tray can be inserted, characterised in that the first panel is adhered underneath the last panel inwardly of the opposite free edge which thus conceals the first crease line with the remaining crease lines defining the vertices of the sleeve.

2. A sleeve according to claim 1 characterised in that the crosssectional shape of the sleeve with a tray concealed therein is that of a trapezium when viewed from either of the open ends.

3. A sleeve according to any of claims 1 or 2 characterised in that the blank from which the sleeve is constructed has six panels, the first panel being defined between a first free edge and a first crease line, a second panel being defined between the first crease line and a second crease line, a third panel being defined between the second crease line and a third crease line, a fourth panel being defined between the third crease line and a fourth crease line, a fifth panel being defined between the fourth crease line and the last crease line, and the last panel being defined between the last crease line and the opposite free edge of the blank.

4. A sleeve according to claim 3 characterised in that the second panel serves as an extension to the third panel and becomes parallel therewith as the sleeve is constrained to assume its flattened 11 condition by relatively shearing the last panel with respect to the fourth panel.

5. A sleeve according to either claim 3 or 4 characterised in that the fourth panel is substantially the same cross-sectional shape and area as the base of the tray which the sleeve is adapted to contain.

6. A sleeve according to any preceding claim characterised in that the last panel is substantially the same cross-sectional area and shape as the tray which it is adapted to contain in a plane parallel and contiguous with the uppermost edge of said tray.

7. A sleeve according to any of preceding claim characterised in that the said opposite free edge which defines the last panel together with the last crease is straight.

8. A sleeve according to claim 7 characterised in that the first panel is adhered underneath said last panel in a location which results in the coincidence of the said opposite free edge with the second crease line after insertion of the tray within the sleeve.

9. A sleeve according to any preceding claim characterised in that it is preferable that the said opposite edge is arcuate at least over some of its length to define one or more flap portions which can be printed with promotional or like information, or can serve to increase the aesthetic appearance of the sleeve.

10. A sleeve according to claim 9 characterised in that said opposite free edge is arcuate over at least some of its length and the first panel is adhered underneath the said last panel in a location which results some aesthetic interplay between the said arcuate opposite free edge and the first crease being which is at least 12 partially visible underneath said free edge when the sleeve is in its erect condition.

11. A sleeve according to any preceding claim characterised in that the one or more flap portions are provided with one or more lines of perforations on at least one side thereof which extend into the last panel such that said flap portions can pulled by a user to initiate tearing of the said perforations to facilitate the opening of the sleeve.

12. A sleeve construction comprising a sleeve according to any of the preceding claims in combination with a tray inserted within the sleeve which constrains said sleeve to adopt its fully erected condition.