GB2366991A

GB2366991A - A Hinged Container Lid with a Sealing Lip

Info

Publication number: GB2366991A
Application number: GB0023351A
Authority: GB
Inventors: Peter Lowe
Original assignee: Egbert H Taylor and Co Ltd
Current assignee: Egbert H Taylor and Co Ltd
Priority date: 2000-09-22
Filing date: 2000-09-22
Publication date: 2002-03-27
Anticipated expiration: 2020-09-22
Also published as: GB0023351D0; GB2366991B

Abstract

A rectangular container lid for an open mouthed container has a substantially continuous depending lip around thee sides of the periphery thereof, and a recess (21) in the lip. The fourth side of the lid comprises the hinged edge. The recess (21) improves sealing of the lid to a container and provides additional stiffening. A flexible seal (24) may be located in the recess (21) to further improve sealing to the container.

Description

Container Lid

This invention relates to a lid for a container, and particularly to a lid having a stiffening rib at the periphery thereof.

Large waste containers of for example over 1000 litres in capacity often have a hinged lid, both to permit deposit of waste, and to permit the container to be emptied by upending. Such lids may be rather large, typically of the order of 1000 mm x 2000 mm and must be light enough to be opened by a small adult. As a result such lids are usually moulded in a plastics material, such as high density polyethylene.

There are however a number of problems in designing a lid which is both strong and lightweight. Firstly the lid must have adequate rigidity and impact resistance; it must for example be able to support the weight of an adult, and be able to resist twisting if opened from one edge. Secondly, the plastics moulding must be dimensionally stable, both when released from the mould, and in service. Thirdly the lid must be relatively inexpensive, and thus use a minimum of raw material. Fourthly, the lid must seat on the container in a manner so as to prevent ingress of water and egress of odours.

It has been proposed to manufacture double skinned lids of this kind by rotational moulding, and to incorporate ribs across the body of the lid in order to enhance stiffness.

The present invention provides an improved lid which has a number of advantages over known lid designs.

According to the invention, there is provided moulded plastics lid for an open mouthed container, the lid being substantially rectangular in plan and having a hinge mounting at one side thereof, the remaining three sides having a substantially continuous depending lip for contact with three corresponding sides of an open mouthed container, and said lip having a substantially continuous recess in the underside thereof.

The recess of the invention substantially stiffens the lid against distortion, both in service and on release from a mould. The recess also provides a better seal against the container and is adapted, if necessary, to locate a soft seal to better prevent ingress of water and egress of odours. Finally the recess allows self jigging of a freshly moulded lid to prevent impermissible distortion due to differential cooling of a freshly moulded lid.

The recess is preferably symmetrical, and may be located substantially in the middle of the depending lip; alternatively the recess may be offset so as to provide inner and outer lip portions of different transverse thickness and/or flexibility. The lip portions may have different lengths so that one protrudes more than the other; this may improve lid location on the container since one of the lip portions may lie just within or just outside the corresponding peripheral wall of a container.

Preferably the recess tapers towards the base thereof.

Other features of the invention will be apparent from the following description of a preferred embodiment shown by way of example only in the accompanying drawings in which: Fig. l is a top perspective view of a lid according to the invention; Fig. 2 is a bottom perspective view corresponding to Fig. 1 ; Fig. 3 is a plan of the underside of the lid; and Fig. 4 is an enlarged scrap section through the periphery of the lid on line 4-4 of Fig. 3.

Fig. 5 corresponds to Fig. 4 and shows a container rim; and Fig. 6 corresponds to Fig. 4 and shows a soft seal.

With reference to Figs. 1-3 a double skinned rotationally moulded container lid 10 has an inner skin 11 and an outer skin 12. The lid has bosses 13 at one end to receive a hinge rod (not shown) by which the lid is hinged to a container. A lifting handle recess 14 is moulded in the other end of the lid.

The lid has a generally outwardly curved shape, the curve extending from end to end and having three longitudinal stiffening ribs 15 on the outside and one protruding mid-rib 16 on the inside. Various recesses 17 are provided on the inside skin 12, the bases of which kiss against the outside skin to improve rigidity.

The periphery of the lid comprises a generally solid depending wall, the underside of which rests against the rim of an open mouthed container. In the case of very large containers, two such lids may be arranged side by side because one larger lid would be too heavy to lift.

The periphery includes a recess 21, shown also in Fig. 4, which extends along both sides of the lid and across the majority of the front edge. In the case of an external handle, the recess can extend continuously along the front edge.

The recess 21 provides several important advantages which are now described.

1. The recess substantially stiffens the periphery of the lid and is particularly important in preventing torsional distortion if the lid is lifted or propped by a comer The recess is provided at the edge of the lid where it can be most effective in contributing to stiffness whilst being of relatively small section. The recess also contributes substantially to the stiffness of a freshly moulded lid, and consequently significantly reduces the likelihood of distortion under cooling.

2. The recess avoids a flat underside to the lid in the region of contact with the container 23 and, as illustrated the relatively narrow lips 22 have a degree of compliance which provides a better seal against a container mouth.

3. The recess provides a convenient location for a soft seal in the event that escape of odours from the container must be prevented. Such a seal may be of any suitable kind, such as a skinned foam section 24 or a hollow elastomeric section, and may be fixed into place with adhesive.

4. The recess provides a very convenient means of reducing the section thickness at the periphery of the lid-thus reducing material content and the risk of differential cooling after moulding.

5. The recess permits instant self-jigging of the lid as it is released from a hot mould, thus ensuring that distortion is avoided as the lid cools to ambient temperature. Hitherto rather complex jigs having clamps have been required to fix the lid to a substrate during cooling-thus procedure is both time consuming and expensive in terms of jig manufacture and maintenance. In the present lid however, all that is required is a simple rigid frame adapted to engage in the recess 21. Means to fix the lid firmly to the frame are not required since by suitable design the newly moulded lid can be arranged to immediately grip the jig with sufficient force to prevent distortion under cooling. At ambient temperature the jig and lid are simply pulled apart.

Claims

Claims 1. A moulded plastics lid for an open mouthed container, the lid being substantially rectangular in plan and having a hinge mounting at one side thereof, the remaining three sides having a substantially continuous depending lip for contact with three corresponding sides of an open mouthed container, and said lip having a substantially continuous recess in the underside thereof.
2. A lid according to claim 1 wherein said lip is symmetrical.
3. A lid according to claim 1 wherein said recess is located substantially in the middle of said lip.
4. A lid according to claim 1 or claim 3 wherein lip portions on either side of said recess depend to the same extent.
5. A lid according to any preceding claim wherein said recess tapers towards the base thereof.
6. A lid according to any preceding claim and further including an elongate seal located within said recess for contact with the mouth of said container in use.
7. A lid according to claim 6 wherein said seal protrudes from said recess.
8. A lid according to claim 7 wherein said seal extends transversely on either side of said recess.
9. A lid substantially as described herein with reference to the accompanying drawings.