# US 5,341,983 A · Locking join for boxes

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- Number: US 5,341,983 A
- Document ID: US5341983A
- Status: Granted
- Kind: A
- Application number: 08/107,573
- Filed: 1993-08-18
- Granted: 1994-08-30
- Earliest claimed: 1992-12-22
- Inventors: Stephen E. McGrath
- Web page: https://patentgrep.com/patent/US5341983A

## CPC

- B65D 5/4279: {Joints, seams, leakproof joints or corners, special connections between panels (B65D5/209 takes precedence)}
- B31B 50/60: Uniting opposed surfaces or edges; Taping
- B65B 51/00: Devices for, or methods of, sealing or securing package folds or closures; Devices for gathering or twisting wrappers, or necks of bags
- B65D 5/10: with end closures formed by inward-folding of self-locking flaps hinged to tubular body
- B65D 5/6697: {Separate lids attached to the container body by a hinge element}
- B65D: CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B31B: MAKING CONTAINERS OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER (making wound articles, e.g. wound tubes, B31C; combined making and filling B65B)
- B65B: MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING (bundling and pressing devices for cigars A24C1/44; devices for tensioning and securing binders adapted to be supported by the article or articles to be bound B25B25/00; applying closure members to bottles, jars or similar containers B67B1/00-B67B6/00; concurrent cleaning, filling and closing of bottles B67C7/00; emptying bottles, jars, cans, casks, barrels or similar containers B67C9/00)

## Abstract

A non-releasable mechanical join useful for permanent joins of plastics material cartons is formed by a row of a plurality of engagement tabs interlocked in a complementary row of slots. The engagement tabs have heads able to pass through the slots in one direction but unable to return in the other direction. The tab heads may be formed as arrowheads, the barbs of which act against edges of the slots are convexly arcuate towards the approaching arrowheads. This may help to provide secure engagement. The greater number of tabs and slots, the greater may be the permanence of the join.

## Claims

### Claim 1

In a carton formed of resilient plastics material, a mechanical joint between first and second plastics material panels;
the first panel having a first edge and a first margin bordering said first edge, a plurality of aligned, spaced apart slots being provided in the margin parallel to the first edge, each the said slots each having a prechosen length;
the second panel having a second edge and having a corresponding plurality of tabs projecting from the second edge;
each one of said tabs having a neck portion and a tab head,
each one of said tab heads having a leading insertion tip having a width less than said prechosen length, and said each one of said tab heads having a trailing non-return edge having a length greater than said prechosen length;
said tabs being engaged in said slots with the neck portions extending through the slots so that the tab heads lie flush with one side of the first margin and the second edge lies against another surface of the first margin.

### Claim 2 (depends on 1)

In a carton, a mechanical joint as claimed in claim 1 in which the tab heads are shaped as arrow heads.

### Claim 3 (depends on 1)

In a carton, a mechanical joint as claimed in claim 1 in which the first and second panels are side walls of the carton.

### Claim 4 (depends on 1)

In a carton, a mechanical joint as claimed in claim 1 in which the slots have arcuate edges convex towards the first edge of the first panel.

### Claim 5 (depends on 4)

In a carton, a mechanical joint as claimed in claim 4 in which the slots additionally have straight edges parallel to the first edge of the first panel.

### Claim 6 (depends on 1)

In a carton, a mechanical joint as claimed in claim 1 in which the mechanical joint forms a hinge between first and second carton parts.

### Claim 7 (depends on 6)

In a carton, a mechanical joint as claimed in claim 6 in which the first carton part is a lid and the second carton part is a body.

### Claim 8 (depends on 7)

In a carton, a mechanical joint as claimed in claim 7 in which the lid carries the tabs and the body carries the slots.