AU731378B2 - Hinged lid container with latches for open and closed positions - Google Patents

Description

WO 9748613PCT/AU97/00381 HINGED LID CONTAINER WITH LATCHES FOR OPEN AND CLOSED POSITIONS Technical Field The present invention relates to containers formed from a syiithetic plastics material and being of the type comprising a body having a rectangular base and four side walls.. and a hinged lid. Such containers are commonly called tote boxes. Mvore particularly tlie invention relates to constructions of tote boxes and like containers in which improved latching means are provided to retain the lids in the open and/or the closed position relative to the body of the container.

Background Art Tote boxes are widely used in industry for the transport of goods, as an examp~le they are used in the motor vehicle assembly industry for the delivery of small comnponent par'ts to assembly plants. An early lpublication in the field o f the present invention is US patent specification 3,463,345 to Brockenstette. This specification describes a tote box having a pair of hinged lids that have interdigitating fingers on their respective free edges that mesh together as the lids are closed The tote boxes are so designed that they are cap~able of being nested with like boxes when the lids are swung open and being stacked with like boxes when the lids are closed. In this arrangement the lids are held in the closed position by gravity and no integral or attached mechanism is provided to latch or otherwise secure the lids in the closed position. This means that if a container is knocked over the contents can be lost or at least scattered.

The desirability of providing some form of locking or latching miechianismn has been recognised by in the field and US patent specifications 4.620,644, 4,765,480 and 5,051,725 all describe tote boxes with a form of latching miechanism for holding the lid or lids ini a closed condition. It has been found by the present inventors that all of the existing latching mechanisms for tote boxes are deficient in one way or another. In many cases it has been found that if the latching mechanism is sufficiently stiff to prevent the tote box bursting open if the box is dropped then it is too stiff to be readily opened by a user of the box. It has also been found with many designs that the latching mechanism is non-intuitive.. ie. a person newly introduced to the box cannot readily work out how to open it. The present WO 97/48613 PCT/AU97/00381 2 invention is, in one aspect directed to an alternative mneanis for latching the lids in tlie closed position which offers the public anl alternative to the arrangements described in the prior art.

The tote boxes described inl the foregoing prior art are all formed with the lids separate from the body of the box. The lids are lingedly connected to the body by cooperative hinge means onl the body and on the lids and, in at least some cases a hinge pin linking the body to the lids. It is also known to link the lids to the body by the use of an integral or molecular hinge. Ini this construction the lid or lids is or are formned integrally with the body through a hinge portion of thin synthetic plastics mnaterial. As the hinge has a degree of natural resilience and memory it has a tendency to return the associated lid to the position it was in relative to the body when the tote box was moulded. Ini this construction it is desirable to provide means for latching the lid in the fully open position. This facilitates the handling of the tote box in use and makes it easier to remove the contents from the box as well as making inechanised handling of the box easier inl the open condition.

The prior art arrangements do not generally utilise a means for holding the lid or lids in anl open condition as the conventional hinges do not have a natural resilience and memory and therefore will hang downwardly inl anl open position. US patent specification 4,620,644 does however p~rovide such a latching mieclianismn for the lid or lids in the open position. A latch is provided with a canii surface which ride over a downwardly directed lip on the body to latch the lid or lids in anl open position. This latching imposes a stress onl the hinges which is transverse to the axis of the hinge. This is probably not a problem with the conventional hinges. The present inventors have found that the imposition of latching stresses to the integral or molecular hinge that are transverse to the axis of the hinge shortens the life of the hinge and thus of the box itself. In a second aspect the invention is directed to latching means that will hold the lid or lids in anl open position with reduced deleterious affect on the longevity of the hinge.

Disclosure of Invention Ini a first aspect the present invention relates to a container formed from a synthetic plastics material and comprising a body having a rectangular base and two opposed pairs of side walls, each side wall having a lower edge formed integrally with the base and each of a p~air~ of side edges formed int~egrally with a corresponding side wall of an adjacent one of the WO 97/48613 PCT/AU97/00381 3 other pair of side walls,. the container additionally has at least one lid hingedly connected to anl upper edge of one of a first pair of the opposed side walls such that the lid or lids may each be pivoted between a closed position in which the lid lies adjacent the upper edges of the side walls and ail open position in which the lid lies adjacent the side wall to which it is hingedly connected.. at least one of the side walls of thle other pair of side walls being provided with latching means to engage with the lids,. the latching means comprising a blade disposed in a plane outside the sidewall to which the latching means is connected, the blade having at its upper end detent means engagable with anl edge of the lid, or at least one of the lids, to releasably retain it in -the closed position.

The latching means preferably extends upwardly from a web that lies in a p~lanle laterally outside the side wall to which the latching means is connected, tile web being connected to the side wall at points'spaced across the sidewall from the latching means. In one embodiment of the invention the web is connected along its upper edge to the upper edge of the side wall to which thle latching means is connected except adjacent the latching means. The web and its associated connection~s to the adjacent side wall of the body preferably also serve as a carrying handle for the container. The latching means, and the web, are preferably provided on each of the other pair of sidewalls of the body such that it is provided with a pair of carrying handles,. one at each end. The latch is preferably spaced from the adjacent side wall of the container by a distance greater than the width of the detent.

This allows the underside of thle detent to be defined by a portion of anl injection mouldinig die that projects through a space between the latch and the side wall.

The detent means preferably comprises anl inwardly extending projection that has a camn surface oin anl upper side that engages with anl edge of the lid as it is moved towards the closed position to cause the latching means to be flexed outwardly as the lid passes the projection. The underside of the lid that will engage the cam surface of the projection preferably is formed with a complementary cam surf-ace.

In a second asp~ect the present invention relates to a container formned from a synthe tic: plastics material and comprising a body having a rectangular base and two opposed pairs of side walls, each side wall having a lower edge formed integrally with the base and each of a pair of side edges WO 97/48613 PCT/AU97/00381 -4 formed integrally with a corresponding side wall of anl adjacent one of the other pair of side walls. the container additionally has at least one lid formned integrally with the body and hingedly connected to anl upper edge of one of a first pair of the opposed side walls through ail integral hinge such that the lid or each lids may be pivoted between a closed position in which the lid lies adjacent the upper edges of the side walls and an open position in which the lid lies adjacent the side wall to which it is hingedly connected, complementary latching mneans being provided respectively oil the body and on the lid,. or at least onl one of the lids, to releasably retain the lid in the open position, these complementary latching means being such that on engagemient of the complementary latching mneans the integral hinge connecting that lid to the body is substantially not stressed in a direction transversely to the axis of the hinge.

In a preferred embodiment of this aspect of the invention the complementary latching means comprise a pair of latching projections that are designed to engage and resiliently deformi at least one of themi in a direction substantially parallel -to the axis of the hinge. In particularly preferred embodiments both of the latching projections are resiliently deformable in directions substantially parallel to the axis of the hinge.

The container is preferably so constructed that it is nestable with a similar container when the lid or lids are neither in the open position nor the closed position. It is also preferably so constructed that it is stackable with a similar container when the lid or lids are in the closed position.

It is preferable that the container is formable in a two piece injection moulding die. This requires all of the surfaces of the container to be formed in the line of draw of the two die halves. This is greatly facilitated by the positioning of the latching means to hold the lid in the closed position outside time side wall to which it is connected.

The container is preferably formed with two lids,. each one connected by an integral or molecular hinge to the upper edge of one of the first p~air of side walls. The lids are preferably each formied with interdigitating webbe 'd teeth along their adjacent edges. It would however be within the scope of the present invention to have a single rigid lid connected to one of the first pair of side walls or to have a single such lid that is hinged along its centre line parallel to the integral hinge.

WO 97/48613 PCT/AU97/00381 The lid or lids are each preferably provided with engagement members on the side of the lid that faces into the container when time lid is in the closed position (the inside face) which engage with one or both sides of time upper edge of at least one of the other pair of side walls. More p)referably the engagement means engage with both sides of each of the other p~air' of side walls. These engagemient meanis resist trapezoidal deformiation of the container, or at least of the lid,. when the container is dropped. This has been found to be one prime cause of hinge failure.

Brief Description of Drawing The following description of a preferred embodiment of the p resent invention is provided as an example of the invention and is described with reference to the accom-panying drawings ini which:- Fig. 1 is a perspective view of a container incorporating both aspects of the present invention with the lids in their closed position; Fig. 2 is a plan view of the container of Fig. 1; Fig. 3 is a side elevation of the container of Fig. 1; Fig. 4 is an end elevation of the container of Fig. 1; Fig. 5 is the samne view as Fig. 4 but with the two lid halves locked in their fully opened positions; Fig. 6 is the samne view as Fig. 1 but with the two lid halves locked in their fully opened position; Fig. 7 is the section view A-A through the container from Fig. 2; Fig. 8 is an enlarged view of the region of the complimentary latching means of Fig. 4 from the direction of arrow B when the lid has been opened to approximately 1800 from its position in Fig. 4.

Best Mode for Carrying Out the Invention The container 10 of Fig. 1 is made as a one piece plastics moulding having a body 1-1, comprising a base 12 and two opposed lpairs of side walls 13 and 14,. and two integral closure memnbers in time form of lids 15 and 16 hinged at their outside edges to respective ones of the side walls 13. The lids and 16 are hingedly connected to the respective side walls 13 by integrally fornied hinge portions 17.

The container 10 is shaped so as to be nestable with another similar container when lids 11,. 12 are opeii. Similarly, when the lids 11. 12 are closed, the containers 10 can be stacked with the base of an upper container WO 97/48613 PCT/AU97/00381 6 fitting snugly within the boundary walls 18 which project upwardly from the lids 15 and 16 of the lower container Lids 15 and 16 are provided with facing co-operating edges which have tongues, teeth or tabs 19 which interdigitate and the teeth on one edge interdigitate with recesses 21 between teeth 19 on the other lid so that when the lids 15 and 16 are closed as shown in Fig. 2, the teeth 19 of lid interdigitate with recesses 21 between teeth 19 of opposite lid 16 and vice versa. The two lids 15 and 16 must be opened and closed concurrently for proper interdigitation. Hinges 17 may be arranged to yield as also may the walls 13 and 1.4 of the container 10 due to the material of its construction which may be a resilient plastics material such as polypropylene.

A handle 22 is formed on each of the side walls 14. This handle 22 comprise a pair of vertical struts 23 extending in spaced apart array downwardly from the upper edge of each wall 14. The outer edges of these struts 23 are joined by web 24. A latch 25 projects upwardly from the upper edge of the web 24 intermediate its length. The latch 25 has an inward facing projection 26 at its free end with a sloping face 27 which engages against the edges of the lids 15 and 16 as they are pushed shut, causing the latch 25 to rotate outwards and allowing the lids 15 and 16 to move into their closed position. The latch 25 then snaps back to its normal unstressed rest position, where projection 26 retains the lids and prevents theni from opening.

The container 10 is opened by pressing the latches 25 outwardly so that the lids 15 and 16 are disengaged by the projection, allowing them to spring open under a rotational force applied by the integral hinges 17.

The latch 25 is lengthened by locating its connection to the web 24 within the web 24 by slots 20 on either side of the latch 25 which extend into the web 24, so that the flexibility provided by the extended length of the latch 25, combined with the torsional flexibility of the web 24, provides the right degree of flexibility and resilience to allow the latch 25 to rotate away from the lids 15 and 16 during closing and opening without permanent deformation but to spring back and remain in the closed position with sufficient rigidity to prevent accidental bursting open if the container 10 is dropped.

The objectives of a latching or locking arrangement of this aspect of the invention are to provide sufficient flexibility to engage and disengage the latch, ensure that the container does not burst open when dropped WO 97/48613 PCT/AU97/00381 7 and prevent permianent deformnation of the latch through misuse. To "fine-tunle" the die-set to optimilse these attributes stiffening ribs call be formed oil tlie side walls of the handle and retaining structures canl be incorporated which will limit the length of travel of the latch, prevent overrotatLion of the latch shaft and prevent s tress concentration.

To provide further security against bursting of the lids and to counter possible outward deformation of the latch due to misuse the lids may h-ave a dimp~le or similar projection (not shown) onl the face of the lid which in the closed positionl engages with a corresponding cavity (not shown) onl the underside of the latch projection 26. We have found that in tests the lid hinges provide sufficient upward force to press the lids against the latches, but in the event that a greater upward force is recluired a further dimple-like projection (or projections) can be formed either onl the underside of the lid, or onl the upper edge of the container, or onl both elemients. where the lid meets the conitainer edge. latches.

'lhe lids 13 and 14 are also provided with releasable holding formations to enable them to be folded back against the side walls '13 of the body 11 of container 10 and retained in that open position. The holding formations comprise a pair of lugs 28 provided onl each lid 13 and '14. Each lug 28 is located onl one side of the respective lid 15 or 16 and adjacent the hinge 17. Each lug 28 has anl inclined cani surface 29 which slopes (when seen with the lids in their closed positions) downwardly in the direction longitudinally of the container 10 and away fronm it. This lug 28, when the lid is opened outwardly and downwardly through 2700 to the position showni in Fig. 6. engages behind a downwardly extending flange 31 having a shoulder 32 facing towards the adjacent wall -14 of the body 11 of the container. The cain surface 29 engages with the vertically disposed shoulder 31 as the lid 15 or 16 is moved into the locked opeii position. As the cam surface 29 moves p)ast the shoulder 31 any stress imposed on the lid 15 or 16 and onl the associated hinge 17 will be along the axis of the hinge 17 rather than transversely to it. The likelihood of this stress causing damage to the hinge 17 is therefor dinminished. The holding lug 28 and flange 32 are resilient so that the lid '15 or 16 can be pulled outwardly away from thle position shown in Fig. 6 and returned to the closed position shown in Fig. 1.

Thme underside of each of the lids -15 and '16 is formed with a rectangular reinforcing rib 33. Each of the ribs 33 is so placed on the WO 97/48613 PCT/AU97/00381 8 underside of the respective one of the lids 15 01r 16 that it overlaps the base of the teeth 19 and the recesses 21 of that lid. Apertures 34 are defined in the recesses 21 within the boundaries of the ledges 33. Each of the teeth 19 is formed oin its underside adjacent to its free end with a short flange 35. The flanges 35 engage with a corresponding onie of the apertures 34 when the lids and 16 are moved to the closed position. The enigagemnent of these ribs and the apertures 34 means that if a downward force is placed on the lids and 16 when they are in the closed position they will be better able to resist being depressed.

The underside of the lids 15 and 16 are also provided with downwardly directed stop members 36 that are located closely adjacent the edges of the lids 15 and 16 and towards their free edges. Thlese stop members abut against the inside surfaces of the side walls 14 when the lids 15 and -16 are in the closed position. This abutment resists trapezoidal deformat~ion of the container 10 if it is dropped on its corner. Such trapezoidal deformation is known -to be a contributing cause to hinge damage in prior art arrangements.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present emnbodiments are, therefore.. to be considered in all respects as illustrative and not restrictive.

Claims (10)

1. A container formed from a synthetic plastics material and comprising a body having a rectangular base and two opposed pairs of side walls, each side wall having a lower edge formed integrally with the base and each of a pair of side edges formed integrally with a corresponding side wall of an adjacent one of the other pair of side walls, the container additionally has at least one lid hingedly connected to an upper edge of one of a first pair of the opposed side walls such that the lid or lids may each be pivoted between a closed position in which the lid lies adjacent the upper edges of the side walls and an open position in which the lid lies adjacent the side wall to which it is hingedly connected, at least one of the side walls of the other pair of side walls being provided with latching means to engage with the lids, the latching means comprising a blade disposed in a plane outside the sidewall S•to which the latching means is connected, the blade having at its upper end 15 detent means engagable with an edge of the lid, or each of the lids, to releasably retain it, or them, in the closed position and wherein the latching means also extends upwardly from a web that lies in a plane laterally outside the side wall to which the latching means is connected, the web being connected to the side wall at points spaced across the sidewall from the 20 latching means. o0002. A container as claimed in claim 1 in which invention the web is connected along its upper edge to the upper edge of the side wall to which the latching means is connected except adjacent the latching means.

3. A container as claimed in claim 1 in which the web and its associated 25 connections to the adjacent side wall of the body serve as a carrying handle for the container.

4. A container as claimed in claim 1 in which the latching means, and the web, are provided on each of the other pair of sidewalls of the body such that container is provided with a pair of carrying handles, one at each end.

5. A container as claimed in claim 1 in which the detent means comprises an inwardly extending projection that has a cam surface on an upper side that engages with an edge of the lid as it is moved towards the closed position to cause the latching means to be flexed outwardly as the lid passes the projection.

6. A container as claimed in claim 1 in which the underside of the lid that will engage the cam surface of the projection is formed with a complementary cam surface.

7. A container as claimed in claim 1 in which the container is so constructed that it is nestable with a similar container when the lid or lids are neither in the open position nor the closed position.

8. A container as claimed in claim 1 in which the container is so constructed that it is stackable with a similar container when the lid or lids are in the closed position.

9. A container as claimed in claim 1 in which all of the surfaces of the container to be formed in the line of draw of the two die halves. A container as claimed in claim in 1 in which the container is formed with two lids, each one connected by an integral or molecular hinge to the upper edge of one of the first pair of side walls.

11. A container as claimed in claim 10 in which the lids are each formed with interdigitating webbed teeth along their adjacent edges.

12. A container as claimed in claim 1 in which the lid or lids are each provided with engagement members on the side of the lid that faces into the container when the lid is in the closed position which engage with one or both sides of the upper edge of at least one of the other pair of side walls. .13. A container as claimed in claim 12 in which the engagement means engage with both sides of each of the other pair of side walls. o• Dated this 22nd day of December 2000 SOCOBELL O.E.M. PTY LIMITED Patent Attorneys for the Applicant: F B RICE CO