GB2213471A

GB2213471A - Cases formed from blanks

Info

Publication number: GB2213471A
Application number: GB8828551A
Authority: GB
Inventors: Jack Lawrence
Original assignee: THAMES CASE Ltd
Current assignee: THAMES CASE Ltd
Priority date: 1987-12-08
Filing date: 1988-12-07
Publication date: 1989-08-16
Anticipated expiration: 2008-12-07
Also published as: GB2213471B; GB8728617D0; GB8828551D0

Abstract

A blank for a standard case has at least at one side thereof slots 5 defining inner flaps 3 and outer flaps 4 of the erected case. The slots 5 widen at their mouths to provide the inner flaps 3 at free ends thereof with sloping corners 6 and give, in erection of the case, ramps along which the outer flaps 4 may slide if inner and outer flaps 3, 4 come into edge contact. The outer flaps 4 may have rebated corners 8. <IMAGE>

Description

A CASE This invention relates to cases and is particularly applicable, though not exclusively so, to cases to be erected, packed and sealed by machinery.

Standard one piece cases are made by the million each day and the basic design has not changed since its conception - a generally rectangular blank with a central area divided by fold lines to define the ends and sides of the case and, along one or two opposite sides of the blank, flaps that in the erected case overlie each other to form the bottom or as the case may be the bottom and the top of the case. Such a blank is referred to herein as a blank for a standard case.

The present invention seeks to overcome these difficulties in the erection particularly the automatic erection of such cases, when flaps can come into edge contact and jam, and provides a blank for a standard case having at least at one side thereof slots defining inner flaps and outer flaps of the erected case, characterised in that the slots widen at their mouths to provide the inner flaps at free ends thereof with sloping corners and give, in erection of the case, ramps along which the outer flaps may slide if inner and outer flaps come into edge contact.

In a further feature of the invention the mouths of the slots may further be shaped so as to provide the outer flap with rebated corners whereby on erection of the case any distortion of the case from square will not result in protrusion of the outer flaps beyond the edge of the case where the outer flaps meet.

In detailed features of the invention, the slot desirably widens outwards along its length, for example at 30, the widening being provided on the outer flap. Another desirable feature that may be used independently or with such widening is to offset the slot centre line from the centre line of the fold separating end and side of the case, towards the outer flap.

To contrast the present invention with the prior art reference should be made to the drawings in which: Fig. 1 is a plan view of a blank for a standard case; Fig. 2 is a partial perspective view of such a case in the process of erection; Fig. 3 is a partial plan view of an erected conventional case showing in exaggerated manner some common faults of such cases; Fig. 4 is a partial plan view of a blank for a case in accordance with the invention; Fig. 5 is a partial view of an erected case in accordance with the invention; and Fig. 6 is a modified view corresponding to Fig. 4.

Referring to Figs. 1 - 3 a blank for a case of conventional board has "standard" slots (2), about 9 - 10 millimetres wide equally disposed about bend lines across the blank. These slots define inner flaps (3) and outer flaps (4) of the erected case. Such slots at one time were about 6 millimetres wide but problems occurred in automatic case erection. There is also a gluing flap (1).

Referring to Fig. 2, when using automatic case erection machinery on the glued blank, inner flaps (3) often foul the outer flaps (4) when the flaps are being closed. If the slots (2) are widened to give more clearance to cure the erection fault then case stability suffers as shown in exaggerated manner by Fig. 3 where the taped erected case is out of square. If a case goes out of square in this manner then the outer flaps (4) protrude over the edge of the case causing difficulties in taping to secure the case.

Embodiments of the invention are illustrated by way of example only in Figs. 4 to 6. Referring to Fig. 4; inner flap (3) and outer flap (4) are separated by slot (5) which widens at its mouth to give the inner flap (3) a sloping corner (6). On erection of the case if the edge of the outer flap (4) meets the inner flap (3) it can slide along the ramp provided by the sloping-corner (6) without fouling.

The slot (5) towards its basal end (7) has parallel edges as is conventional and can be narrower than is usual (i.e. can be 6 millimetres for conventional thickness board) since the problem of fouling is met. Referring to Fig. 5 showing the erected case it can be seen that by having rebates (8) on the corners of the outer flaps (4) distortion of the case from square (which is less likely to occur in any event due to the narrow slot widths possible) does not result in protrusion of the outer flap (4) from the edge of the case where the outer flaps meet.

In the blank of Fig. 6 the slot (9) widens by 30 and is offset whereby as seen the 8 mm width lies 3 mm left and 5 mm right of the centre line (10) of the case side to caseend fold. The sloping corner 6 begins 30 mm from the mouth of the slot.

The invention is not limited to the particular forms of inner flap sloping corner (6) and outer flap rebated corner (8) shown and any shape that fulfils the functions set out above is intended to fall within these terms.

Claims

1. A blank for a standard case having at least at one side thereof slots defining inner flaps and outer flaps of the erected case, characterised in that the slots widen at their mouths to provide the inner flaps at free ends thereof with sloping corners and give, in erection of the case, ramps along which the outer flaps may slide if inner and outer flaps come into edge contact.

2. A blank according to claim 1 wherein the mouths of the slots are further shaped so as to provide the outer flap with rebated corners whereby on erection of the case any distortion of the case from square will not result in protrusion of the outer flap beyond the edge of the case where the outer flaps meet.

3. A blank according to claim 1 or 2, wherein the slot widens outwards along its length, for example at 30, the widening being provided on the outer flap.

4. A blank according to any preceding claim, wherein the slot centre lines are offset, towards the outer flaps, from the centre lines of the folds separating ends and sides of the case.

5. A blank for a standard case substantially as herein described and shown in Figs. 4 and 5 or Fig. 6 of the drawings.

6. A case erected from the blank of any preceding claim.