GB2293160A

GB2293160A - Collapsible container or pallet frame

Info

Publication number: GB2293160A
Application number: GB9518550A
Authority: GB
Inventors: Gina Verwold
Original assignee: Lin Pac Mouldings Ltd
Current assignee: Linpac Mouldings Ltd
Priority date: 1994-09-15
Filing date: 1995-09-11
Publication date: 1996-03-20
Anticipated expiration: 2015-09-11
Also published as: GB2293160B; GB9518550D0

Abstract

A frame for assembly with a pallet base 1 Fig 1 to form a container consists of two identical frame parts 2, 3. Each frame part has a hook shaped tongue 6 on a hinged wall 9Z and a pocket 7 in a hinged wall 9a. For assembly of the frame the tongue 6 on one frame part is inserted into the pocket 7 of the other frame part with a pivotal motion so that a retaining part 6a of the tongue engages behind a retaining surface in the pocket to restrain the two frame parts from being separated. Each frame part carries a pivotted latch member 17 Fig 5 and a lug 16. Upon assembly of the frame the lug 16 is captured by pivotal movement of the latch member 17 to retain together the frame parts 2, 3 and prevent those parts from being pivotted in a sense to unhook the tongues from the pockets in which they are respectively received. Secondary locking means may be provided by which the latch member 17 can be retained in engagement with the lug 16. The latch member 17 engages with the lug 16 in a direction perpendicular to the plane of the co-operating walls 9a and 9Z and preferably the secondary locking means is actuated in a direction parallel to the plane of the walls 9a and 9Z. The secondary locking means may be a sliding bolt on the member 17 which engages a recess in the lug 16. <IMAGE>

Description

TITLE A frame and a container having upstanding side walls provided by the frame" TECHNICAL FIELD & BACKGROUND ART The present invention relates to a frame and to a container having upstanding side walls provided by the frame. More particularly, the invention concerns frames of the kind which are fitted to a base, typically a pallet, for the purpose of providing the base with an upstanding side wail in the formation of an open topped container.

It is known to provide a frame as an assembly of a plurality of frame parts, which parts are interconnected together on the base in the structure of a container so that the container can readily be assembled for use in the storage or transportation of goods or dis-assembled when not in use for convenience of storage or transportation of its component parts. It is an object of the present invention to provide a frame of the kind aforementioned and also a container which includes such a frame and which frame lends itself to efficient assembly and dis-assembly, and can provide a robust structure with its component parts securely retained together when the frame is assembled.

STATEMENTS OF INVENTION E ADVANTAGES According to the present invention there is provided a frame for assembling with a base to provide upstanding side walls thereon in the construction of a container, the frame comprising two substantially identical frame parts, each frame part having a tongue of substantially hook shaped profile extending from an end of a first wall portion of that part substantially coplanar with the wall portion from where it extends and a pocket located in an end of a further wall portion of that frame part, the frame being assembled by the hook shaped tongue on the first wall portion of each frame part being received in the pocket of the further wall portion of the respective other frame part py pivotal movement of one frame part relative to the other frame part to cause a retaining part of a projection of the hook shaped tongue to be engaged behind a retaining surface presented in the pocket in which that tongue is received so that the co-operating hook shaped tongues and pockets restrain the two frame parts from being separated and in which locking means is provided for releasably connecting the frame parts together, the locking means serving to retain together adjacent first and further wall portions connected by a co-operating tongue and pocket and being actuated in a direction which is transverse to the plane of the wall portions adjacent to said co-operating tongue and pocket.

Further according to the present invention there is provided a container comprising the combination of a frame as specified in the immediately preceding paragraph and a base to which the frame is fitted to provide upstanding side walls on the base.

By the present invention, the frame (which may be referred to as a pallet frame) has its two frame parts coupled together by co-operation between the hook shaped tongues and the pockets in which those tongues are respectively received and which engagement is effected by relative pivotal movement between the frame parts. This pivotal movement causes retaining parts of the hook shaped tongues to engage behind respective retaining surfaces in the pockets. Dis-engagement between the frame parts to dis-assemble the frame is achieved by pivotting the two frame parts relative to each other in a reverse direction to that previously mentioned (effectively to unhook the tongues from the pockets in which they respectively engage).Preferably the pockets are substantially complementary to the tongues which they respectively receive so that when a tongue is received fully by a pocket, the opening or entrance to that pocket is substantially filled by the tongue. With this latter arrangement the co-operation between a tongue and a pocket provides a bracing effect which supports the side of the frame against horizontal or transverse loads to which the frame may be subjected in use. If required an array of two or more substantially co-planar tongues can be provided on the first wall portion and a corresponding number of pockets in the further wall portion so that each of the tongues in the array is received in a separate pocket during assembly of the frame.Such an array of tongues can have a single hook shaped tongue in accordance with the invention whilst the other tongue or tongues in the array merely co-operate with the respective pockets to provide an increase in the surface area of overlap between the wall portions and thereby strengthening to resist transverse loads on the wall portions.

The locking means when in an engage condition serves to retain together adjacent wall portions which are connected by a co-operating hook shaped tongue and pocket.

More particularly the locking means acts to restrain the adjacent co-operating wall portions from exhibiting the aforementioned relative pivotal movement in the "reverse direction" and thereby prevents the hook shaped tongues from being unhooked from the pockets. The locking means is intended to releasably retain the coupled frame parts together in a firm and secure manner and is actuated in a direction transverse to the plane of the wall portions on which it acts to ensure that the retention provided is secure and is readily and conveniently available. In a simple case the locking means comprises coinciding transverse bores which extend through a pocket and a tongue which is received within that pocket.The two frame parts are locked or connected together by a re-usable locking pin, a destructable seal or other lock component which is inserted through the coinciding bores in a direction that is transverse to the plane of the wall portions adjacent to the co-operating tongue and pocket in which the coinciding bores are located.

Alternatively or in addition, the locking means can be in the form of a latch member which is carried by and displaceable relative to one of the wall portions and a lug carried by the other of the wall portions. The latch member has a wall which is displaceable transversely to the plane of the wall portions adjacent to the co-operating tongue and pocket so that it can engage the lug when the frame is assembled. Engagement of the latch member with the lug retains together the first and further wall portions, thereby preventing the two frame parts from pivotting relative to each other (as would be required to disengage the hook shaped tongue from the pocket in which that tongue is received). In a preferred arrangement the latch member is pivotally mounted on the wall portion which carries it to be capable of rocking between a condition in which it engages with the lug and a dis-engage condition in which it is clear of the lug to permit the two frame parts to pivot relative to each other for their separation.

Preferably the axis about which the latch member pivots is located in the plane of the wall portion which carries that member and to achieve this the latch member may be located in a recess in the wall portion so that it is presented on the exterior of the frame for convenience of manual operation.

By the invention the locking means is actuated in a direction transverse to the plane of the wall portions adjacent to the co-operating tongue and pocket and the necessary pivotal motion between the frame parts to effect release of a co-operating tongue and pocket is also effected in the aforementioned plane of the wall portions.

As a consequence such forces as may be applied to the frame when assembled in a sense to pivot the frame parts out of engagement with each other will be countered by the restraining effect of the locking means in its engage condition. Furthermore, surfaces of the locking means which, in its engage condition, co-operate together (for example between the latch member and lug) to effect the aforementioned restraint may be so profiled that when a force is applied to the frame parts in a sense to pivot those parts relative to each other to disengage the tongues and pockets, a reaction develops between the co-operating surfaces in a sense which increases the restraining effect of the locking means.

Where the locking means comprises the aforementioned latch member, it is preferred that means is provided for restraining displacement of the latch member between its engage and disengage conditions and which restraining means is overcome by manual pressure applied to the latch member. Such restraining means, which may simply comprise an abutment over which the latch member is displaceable by flexure in response to adequate manual pressure being applied to the latch member, has the advantage that it facilitates use of the frame parts single handedly in so far as the latch member can be maintained in its dis-engage condition until purposely displaced, at the option of the handler, to its engage condition.

With the aforementioned locking means constituting a primary locking means, a secondary locking means may be provided which is adjustable to a position in which it retains the primary locking means in a condition in which the primary locking means is intended to retain together the adjacent first and further wall portions. It is preferred that the secondary locking means is actuated in a direction which is transverse to the direction in which the primary locking means is actuated - thereby requiring a handler to effect two distinct movements which are at right angles to each other, one to the secondary locking means and the other to the primary locking means before the two frame parts can be pivotted and dis-engaged from each other.This alleviates the likelihood of inadvertently adjusting both the secondary and the primary locking means to conditions in which the two frame parts can be pivotted relative to each other and the co-operating tongues and pockets dis-engaged. When the primary locking means comprises the latch member and the lug as aforementioned, the secondary locking means is conveniently carried by and displaceable relative to the latch member to a condition in which it restrains the latch member from pivotal movement from its engage condition with the lug. In this latter arrangement the secondary locking means may comprise a catch that is slidable on the latch member to engage with the lug (whilst the latch member is in engagement with the lug) and thereby restrain the latch member from pivotal movement out of engagement with the lug.

The frame parts will usually be formed as plastics moulded components and when assembled provide a frame of generally parallelopipedon shape. Such a rectangular shape for the frame is convenient for its use in forming a container with a so-called "Euro pallet" having a base or deck size of 1200 x 800 mm. Preferably the frame of the present invention is of modular size for the Euro pallet whereby it is dimensioned so that two or more such frames can be used to fill the pallet deck in modular fashion, for example each assembled frame may have a basic size, in plan, of 600 x 800 mm.

A further preferred feature is that either or both of the first and further wall portions is hingedly connected in the frame part so that the frame part can be folded or collapsed to a compact condition convenient for its storage and transportation when not in use. In a preferred arrangement each frame part has a rear wall part on which one or more side wall portions are hingedly connected so that the side wall portion or portions can be hinged to positions in which it or they closely overlie the rear wall part to form a compact component. With hinged side wall portions it is preferred that at a hinged connection the wall parts joined by the hinge overlap when the frame is assembled.These overlapping wall parts can abut each other and alleviate strain on the hinge in response to internal or external horizontal forces on the frame part subjected in a direction perpendicular to the plane of the wall parts in the region of the hinge.

DRAWINGS Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying illustrative drawings, in which: Figure 1 is a perspective view of two frame parts constructed in accordance with the present invention located on a wood pallet base in the construction of a container; Figure 2 is a similar view to that shown in Figure 1 and illustrates the two frame parts in the final stages of their assembly to form the frame on the pallet; Figure 3 is a perspective view of a plurality of frame parts similar to that shown in Figure 1 superimposed to form a stack on a plastics pallet base and which frame parts are presented for connection to additional frame parts in the erection of a container; Figure 4 is a side view of co-operating wall portions of two frame parts and includes a locking means for those frame parts;; Figure 5 is a scrap view of part of the wall portions shown in Figure 4 to better illustrate the locking means; Figure 6 is a perspective view showing a modified form of frame part; Figure 7 is a section through locking means similar to that shown in Figure 4, and Figure 8 is a section through a locking means similar to that shown in Figure 7 and modified to include a secondary locking means.

DETAILED DESCRIPTION OF DRAWINGS Figure 1 shows a wooden pallet 1 which is to provide the base of a container of generally parallelopipedon shape and having upstanding side walls which are provided by a container or pallet frame mounted on the wooden pallet.

The frame is formed by collapsible or foldable frame parts 2 and 3 which are preferably moulded in plastics. The frame parts 2 and 3 are identical and are foldable (in the manner shown for the frame part 3 on the left of the pallet in Figure 1) for convenience of storage and handling when not in use. When unfolded the two frame parts are combined to form the container or pallet frame as generally indicated at 4 in Figure 2.

The pallet frame therefore consists of the two frame parts 2 and 3 which are connected together at co-operating edges along split or separating lines 5. At each separating line 5 a tongue 6 on each frame part is received in a pocket 7 on the respective other frame part. The tongue 6 is substantially co-planar with a wall portion of the frame part from which it extends. The pocket 7 is substantially coplanar with a wall portion of the frame part in which it is located and opens into an end face at an edge of that wall portion for presentation to the tongue 6 which it receives in erecting the pallet frame 4.

As will be apparent from Figures 1 and 2, each frame part 2 and 3 of the present embodiment is formed with a generally U-shaped end wall portion 8 and two side wall portions 9 hingedly connected to the portion 8. Free end faces at the un-hinged side edges of the side wall portions 9 and have, in one case, the tongue 6 and in the other case the pocket 7. For convenience the side wall portion having the tongue 6 is shown at 9Z and that having the pocket 7 is shown at 9a. It will be noted that the Ushaped end wall portion presents opposed stub-walls 8a and 8b to which the side wall portions are respectively hinged.

These stub walls are of different heights to permit the side wall portions 9a and 9Z to be pivotted on their respective hinges to a collapsed condition in which they both overlie the end wall portion and are parallel therewith with the side wall portion 9a sandwiched between the end wall portion and the side wall portion 9Z.

As will also be apparent from Figures 1 and 2, the pallet frame 4 can be assembled without the use of tools by unfolding each collapsed frame part 2 and 3 into a U-shaped structure and coupling the two parts together by inserting the tongue 6 of each frame part into the pocket 7 of the other part.

Each tongue 6 is of generally hook shape to present an upwardly directed projection 6c having retaining part 6a while each pocket 7 has a profile which substantially corresponds to that of the tongue so that the two frame parts can be fitted together by a lever or pivotting action in which the retaining part 6A of each tongue engages behind a corresponding retaining surface presented by the wall portion in the pocket in which that tongue is received.

It will be seen from Figure 1 that the depth of the tongue 6 extends over a substantial part length of the side edge of the wall portion 9Z from which it projects and also that the tongue projects longitudinally from that side edge to present a considerable surface area. By providing the tongue and pocket engagement between the frame parts 2 and 3, the pallet frame 4 can be afforded with an extremely stable configuration, particularly since forces directed laterally or in a perpendicular direction against the side walls formed by the portions 9 can be taken through the relatively large area presented between the co-operating tongues and sockets (rather than such forces being concentrated along the separating lines 5). In other words, the wall portions 9 of the two frame parts when connected together will overlap each other to a considerable extent by the presence of the tongues 5.

Similarly it is preferred that the hinges between the wall portions 9 and the end wall portions 8 are arranged so that the wall portions 9 overlap, to a considerable extent, the stub walls 8a and 8b to which they are respectively hinged so that this overlap can accommodate forces which may be directed from the interior of the pallet frame onto the hinged regions in a direction perpendicularly to the planes of the wall portions 9. Furthermore, the co-operation between retaining parts 6a on the projections 6c of hookshaped tongues 6 and the retaining surfaces in the pockets which receive those tongues acts to hold the two frame parts together against internal forces within the pallet wall which are applied in a direction which tends to separate the frame parts 2 and 3.

A deep container may be constructed by stacking several pallet frames 4 vertically one on another to increase the height of the container walls from the pallet base. Such an arrangement is partly shown in Figure 3 where four frame parts are stacked vertically on, in this case, a plastics pallet 1. In Figure 3 only one half of the pallet frames 2 or 3 have been assembled, it being realised that the other halves 3 or 2 can be added to the structure as required (or alternatively removed from the structure) by the aforementioned lever or pivotting action.

By the facility to add frame parts to the container structure, contents of the container can be enclosed progressively or alternatively by removing frame parts such contents can be revealed progressively which may facilitate access to those contents whilst they are still supported by such frame parts as are provided on the pallet 1.

It will be realise.d that the projection 6c and the retaining part 6a provides the tongue 6 with substantially L-shaped upper profile but it will be realised that this profile is not necessarily right-angled, in fact it is preferably obtuse to provide the projection 6c with a chamfer which provides a lead-in to the pocket 7 in which it is received. Furthermore a bottom edge 6b on the tongue is provided with a convex curved profile which, by co-operating with a complementary profile presented in the pocket 7 in which it is received together with the chamfered projection 6c facilitates the pivotting action required for fitting together or taking apart the two pallet frames with a smooth sliding motion.Also the opening of the pocket 7 presented in the end face at the edge of the side wall portion 9a is substantially complementary in size and shape to the section of the tongue 6 at the interface of that tongue with the end face at the edge of the side wall portion 9Z so that when a tongue 6 is fully received by a pocket 7, the opposed end faces of the wall portions 9a and 9Z are substantially in abutment and such weakening as occurs in the wall portions 9a by the presence of the pockets 7 is substantially compensated for by the fitment of the tongues in those pockets so that the connected wall portions can accommodate substantial forces without the likelihood of damaging or deforming the pallet frames.

The frame parts 2 and 3 are provided with a locking means which may be engaged to retain those two parts together by effectively preventing one part from being pivotted relative to the other part in a sense to unhook the tongues 6 from the pockets 7 in which they are respectively received and which may be disengaged to permit the aforementioned pivotal action required to unhook the tongues from the pockets and separate the two frame parts.

For convenience of description and illustration the locking means has not been shown in Figures 1 to 3 but its structure and operation will be apparent from the following description with reference to drawings showing different embodiments and modifications for the two frame parts from which the pallet frame can be constructed.

In the embodiment of Figure 4 the side wall portion 9Z of the frame part is provided with three vertically spaced tongues 6x, 6y and 6z which effectively replace the single tongue 6 shown in Figure 1. These three tongues are coplanar with the wall portion 9Z and together provide a considerable surface area over which the frame parts are connected. The uppermost tongue 6x is profiled to present a generally hook shaped formation with the upstanding projection 6c having the retaining part 6a and the curved edge 6b - this uppermost tongue is similar to and serves a similar purpose as the tongue 6 shown in Figure 1 whilst the two lower tongues 6y and 62 are primarily intended for guidance and support in effecting the coupling between two frame parts.

The wall portion 9 is provided with a vertically spaced array of three pockets 7x, 7y and 7z which extend in the plane of that wall and open into an end face of the wall for receiving, one each, the respective tongues 6x, 6y and 6z. The uppermost pocket 7x is shaped so that its upper edge presents a profile which is substantially complementary to the upper edge profile at the projection 6c of the uppermost tongue 6x so that the uppermost tongue 6x can be fitted into the uppermost pocket 7x by a pivotting action (similarly to the previously described embodiment) for the projection 6c to be closely accommodated within the complementary profile 10 as the wall portion 9Z is effectively hooked into the wall portion 9a.The three pockets 7x. 7y and 7z are separated by plastics webs 11 and as the uppermost tongue 6x is hooked into the uppermost pocket 7x by the action of pivotting one frame part relative to the other frame part, the middle tongue 6y is received by the middle pocket 7y and the lowermost tongue 6z is received by the lowermost pocket 7z so that whet. the three tongues are received fully by the respective pockets, the opposing end faces presented at the edges of the wall parts 9a and 9Z are substantially in abutment. The two lower tongues 6y and 6z are provided with parabolic profiles to facilitate their guidance into the pockets 7y and 7z. The lowermost pocket 7z is partly defined by a web 12 which presents a concave bottom face to that pocket that is complementary in profile to the bottom convexly curved edge of the lowermost tongue 6z.As the lowermost tongue 6z enters the lowermost pocket 7z, the bottom edge of that tongue co-operates with the profiled surface 12 and this co-operation, when the two frame parts are fully fitted together determines the vertical cooperation between the uppermost tongue 6x and its pocket 7x (that is the co-operation between the projection 6c and the profiled surface 10). Usually the wall portion 9 will be double-walled or double-skinned, at least in the region of the pockets 7, so that the pockets 7 are fully closed both on the interior and on the exterior of the pallet frame.

The frame parts 2 and 3 shown in Figure 4 are provided with two locking means as aforementioned although one or other of such locking means can be provided if it is considered adequate to prevent the two frame parts from being uncoupled and that it provides an appropriate standard of security for the intended use of the container.

A first such locking means comprises a bore 14 in the wall portion 9A which extends through the lowermost pocket 7z.

A bore 15 is also provided in the lowermost tongue 6z of the wall portion 9Z. The bores 14 and 15 are located so that when the frame parts 2 and 3 are fitted together with the three tongues received fully within the three pockets, those bores 14 and 15 coincide and a seal, locking pin or other convenient form of locking component (not shown) can be inserted through the coinciding bores to lock the frame parts together whereby one part is prevented from pivotting relative to the other part in a sense to disengage the tongues from the pockets. It will be appreciated that the locking component engages with the coinciding bores 14 and 15 in a transverse or perpendicular direction to the plane of the co-operating wall portions 9a and 9Z.

The second form of locking means shown in Figures 4 and 5 comprises a lug 16 having a head 16a and a neck 16b which projects from the end face of the wall portion 9Z between the lower two tongues 6y and 6z and a latch member 17 pivotally mounted to exhibit a rocking motion on the wall portion 9a adjacent to the end face of that wall portion in which the three pockets are presented and about an axis which extends in the plane of the wall portion 9a substantially parallel with the split line 5. More particularly the latch member 17 is mounted in a recess 18 in the wall portion 9a formed between two adjacent webs 11 so that it is presented from a side face of the wall portion 9a externally of the pallet frame.Conveniently the latch member is formed as a plastics moulding which includes pivot pins 19 that snap engage in complementary seatings in the webs 11 which provide appropriate bearings for pivotal movement of the latch member with a rocking motion about the axis of the pins 19. The latch member 17 has an end wall 17a which includes a recess 17b which, by rocking motion of the latch member about the pivots 19, is movable into and out of the plane of the wall portion 9a in the end face of that wall portion.The lug 16 and latch member 17 are positioned and arranged so that as the two frame parts 2 and 3 are fitted together and three tongues are received in the respective three pockets, the lug 16 is received in the recess 18 and, with the two frame parts fully fitted together, the latch member 17 can be rocked about its pivot pins for the recess 17b in its end wall 17a to engage over the neck 16b of the lug 16 for the head 16a of the lug to be captured by the latch member and thereby prevent the two frame parts from being separated.

Separation of the two frame parts can be effected simply by pivotting the latch member 17 to disengage its recessed wall 17A from the lug 16. The head 16a of the lug 16 is preferably tapered to provide a lead-in surface for engagement with the latch member 17. In the event that the latch member 17 is in its locked condition as the two frame parts are being coupled together the tapered lead-in surface of the lug head 16a can engage in the recess 17b of the end wall 17a to displace the latch member sufficiently for the lug 16 to be received in the recess 18 of the wall portion 9a following which the end wall 17a can engage over the head 16a of the lug 16 to retain the wall parts together.If required, co-operating abutments can be provided between the latch member 17 and the adjacent webs 11 (or other parts of the wall portion 9a); these abutments may be positioned and arranged so that they cooperate with each other in a sense to retain the latch member when in its lock condition and thereby prevent the locking means from inadvertently being disengaged (even though the latch member can readily be pivotted to its unlock condition by a firm pressure applied to that member in a sense to lift the wall 17a clear of the head 16a of the lug. Where such abutments are provided, the temporary retaining force which they exhibit to hold the latch member in its lock condition may be such that if the lug 16 is moved to engage with the latch member 17 whilst it is in its lock condition, the resilience of the plastics for the latch member 17 permits that member to flex and snap engage over the head 16a of the lug 16 without disengaging the cooperating abutments. In addition, or alternatively, cooperating abutments can be provided as aforementioned which serve to temporarily retain the latch member 17 when pivotted to its unlock condition clear of the lug 16 to alleviate the latch member from accidentally rocking back into its lock condition - this latter arrangement may facilitate disassembly of the pallet frame single handedly.

The lug 16 and recessed wall 17a can be modified from that shown in Figure 5 by having the faces thereof which co-operate when the wall 17a locks behind the head 16a of the lug profiled to provide an oblique contact surface which effectively serves to intensify the retaining force of the latch member in its lock condition on the lug 16 in response to a force which is directed to separate the two wall portions 9a and 9Z.

In the previously described embodiments each frame part consists of an end wall portion 8 and two side wall portions 9a and 9z each of which is hingedly connected to the end wall portion. Figure 6 shows an embodiment of a frame part 2 or 3 having the end wall portion 8 to which is hingedly connected a single side wall portion 9a. The side wall portion 9 has the three tongues 6x, 6y and 6z projecting from its end face remote from its hinged end in a similar manner to the wall portion 9Z in Figure 4.

However, in the embodiment of Figure 6 the three pockets 7x, 7y and 7z are provided in the stub wall 8a of the end wall portion 8. The pallet frame is assembled from two identical frame parts as shown in Figure 6 in a manner similar to the previously described embodiments except that the rectangular frame is formed by four hingedly connected wall portions rather than six such portions as in the previously described embodiments. For convenience the locking means has been omitted from Figure 6.

It will be appreciated that the rectangular pallet frames will be structured with their wall portions and stub walls of appropriate length as required to fit the pallet base or as a module of the base size, for example 600 millimetres by 800 millimetres which is half the size of a conventional standard pallet deck so that two pallet frames can be accommodated on such a deck for optimum use of its tload carrying capacity. It will also be appreciated that containers formed by the base and open topped pallet frames will usually be provided with top closures or lids as indicated at 10 in Figure 3.The upper edges of the walls of the frame parts are conveniently rebated or otherwise contoured as shown at 60 in Figure 6 to accommodate the lid 10 and if required this lid can serve as a partition between pallet frames in a vertical stack as shown in Figure 3 so that the container which is built up of the pallet base and several stacked pallet frames can be divided horizontally into separate compartments. The bottom edges of the wall portions are provided with a lip or shoulder 61 as shown in Figure 6 which is contoured so that the pallet frame can sit on the deck of a pallet and be restrained by the shoulder or lip 61 from displacement over the pallet deck (that is horizontally relative to the pallet).The aforementioned shoulder 61 or contouring of the bottom edges of the frame also permits two pallet frames to be stacked vertically one on the other as previously mentioned and restrains relative displacement in a horizontal direction between adjacent pallet frames to provide a stable stack.

Figure 7 shows a modification of the locking means provided by the co-operating lug 16 and latch member 17 where it will be seen from the section that a wall 171 of the wall portion 9a in which the latch member 17 is pivotally mounted is provided with a protruberance or abutment 170 which provides a cam surface within the recess 18. The abutment 170 is located so that it projects into the arcuate path of movement exhibited by a tail-end 160 of the catch member 17 remote from its recessed wall 17a.

The latch member when in its unlock condition (as shown in Figure 7) has its tail-end 160 clear of the protruberance 170 but is restrained from rocking about the pivots 19 into its lock condition by abutment of the end 160 with the cam surface of the protruberance 170. However, displacement of the latch member 17 into its lock condition merely requires firm manual pressure to be applied to the end of the latch member adjacent to its wall 17a to move the tailend 160 over and clear of the protruberance 170 so that the recess 17b of the wall 17a engages over the neck 16b of the lug 16 to capture the head 16a of the lug.The protruberance 170 then serves to restrain rocking movement of the latch member in a sense to unlock the lug until firm manual pressure is applied to the latch member adjacent its tail end 160 to overcome the resistance of the protruberance 170 and rock the latch member into its unlock condition. Displacement of the tail-end 160 of the latch member over the protruberance 170 is achieved by resilient deformation of the plastics material. Consequently the co-operation between the protruberance 170 and the latch member 17 provides a simple and convenient means for alleviating inadvertent pivotal movement of the latch member between its lock and unlock conditions.Unlike the lug 16 shown in Figure 5, that shown in Figure 7 has a hollow wedge shaped formation (which is convenient for moulding) to present a leading inclined wall 16c which may be flat whilst the recess 17b in the end wall 17a of the catch member is appropriately profiled and shaped to slide up the wedge-shaped surface of the lug and engage over the neck 16b thereof to capture the head 16a.

The modification in Figure 8 shows a locking means similar to that of Figure 7 but with the tongues 6 of one frame part fully engaged in the pockets 7 of the other frame part so that the latch member 17 can engage with the lug 16 (in Figure 8 the latch member 17 is shown by continuous lines in its lock condition to capture the head 16a of the lug and by dotted lines in its unlock condition to permit separation of the frame parts). Furthermore, in Figure 8 the locking means is provided with a secondary lock 190 which is engageable when the latch member 17 is in its lock condition to prevent that member from pivotting into its unlock condition and disengagable to permit pivotal movement of the latch member from its lock to its unlock condition.The secondary lock 190 is provided by a catch 200 which is slidably mounted in a slot 201 in the latch member 17 so that a handle 210 of the catch 200 is presented on the face of the wall portion 9a externally of the frame for convenient access by the user. The head 16a of the lug 16 is provided in its inclined leading wall 16c with a central opening 180. The catch 200 and opening 180 are arranged so that when the latch member is in its lock condition, the catch 200 can be slidably displaced along the slot 201 and relative to the latch member 17 so that a projecting part 202 of the catch is received within the opening 180 of the lug head and abuts against the lug head in the opening 180 to prevent pivotal movement of the latch member 17 into its unlock condition.

To permit this latter movement it is merely necessary to manually displace the catch 200 along the slot 201 until the projection 202 is clear of the lug 16. Conveniently the projection 202 of the catch is profiled so that if the catch 200 is located in the slot 201 at a position where it is intended to engage the secondary lock even though the latch member 17 is in its unlock condition, upon pivotal movement of the latch member 17 into its lock condition the projection 202 can abut the wedge shaped wall 16c on the head of the lug 16 to cause the catch 200 to be displaced automatically along the slot 201 into its disengaged condition as the catch member is moved into its lock condition.If required, abutments can be provided between the catch 200 of the secondary lock and the latch member 17 along the track over which the catch 200 is displaceable so that such abutments can retain the catch 200 in its engaged condition until the resistance of the co-operating abutments is overcome by firm manual pressure to slide the catch along the latch member to its disengaged condition.The secondary lock 190 and latch member 17 therefore operate on the principle that two movements at right angles to each other have to be carried out for the purpose of unlocking the two frame parts 2 and 3; that is the catch 200 has to be displaced in a direction parallel to the wall portion 9a to its disengaged position after which a manual pressure has to be applied at right angles to the plane of the wall portion 9a onto the latch member 17 to cause that latch member to rock and clear the head of the lug 16.

Whilst a single latch member 17 and co-operating lug 16 will provide adequate locking between two co-operating wall portions in most applications of the pallet frame, it will be appreciated that two or more such co-operating latch members and lugs can be provided at positions spaced along the split line 5. Also, although in the above examples the lug 16 is positioned on the wall portion 9Z and the latch member 17 is positioned on the wall portion 9a, this positioning can be reversed; furthermore in the embodiment shown in Figure 6 the stub wall 8a will have either a latch member 17 or a lug 16 as appropriate.

Claims

1. A frame for assembling with a base to provide ,upstanding side walls thereon in the construction of a container, the frame comprising two substantially identical frame parts, each frame part having a tongue of substantially hook shaped profile extending from an end of a first wall portion of that part substantially coplanar with the wall portion from where it extends and a pocket located in an end of a further wall portion of that frame part, the frame being assembled by the hook shaped tongue on the first wall portion of each frame part being received in the pocket of the further wall portion of the respective other frame part by pivotal movement of one frame part relative to the other frame part to cause a retaining part of a projection of the hook shaped tongue to be engaged behind a retaining surface presented in the pocket in which that tongue is received so that the co-operating hook shaped tongues and pockets restrain the two frame parts from being separated and in which locking means is provided for releasably connecting the frame parts together, the locking means serving to retain together adjacent first and further wall portions connected by a co-operating tongue and pocket and being actuated in a direction which is transverse to the plane of the wall portions adjacent to said co-operating tongue and pocket.

2. A frame as claimed in claim 1 in which the hook shaped tongue has its projection at one edge surface thereof and an opposite edge surface thereof is provided with a convex profile which provides a lead-in surface into the pocket as the tongue is received by the pocket by pivotal movement of one frame part relative to the other frame part.

3. A frame as claimed in either claim 1 or claim 2 in which each frame part has at least two tongues in a spaced array extending from said end of the first wall portion substantially coplanar with the wall portion from where they extend and a corresponding number of pockets disposed in a complementary array in said end of the further wall portion for each said pocket to receive a tongue during assembly of the frame from the two frame parts and wherein the said hook shaped tongue is provided by at least one of said array of tongues.

4. A frame as claimed in any one of the preceding claims in which the or a tongue has a profiled surface which cooperates with the pocket in which it is received to displace the co-operating wall portions relative to each other in a sense to direct the retaining part of the hook shaped tongue into co-operation with a retaining surface in the pocket in which the hook shaped tongue is received.

5. A frame as claimed in claim 4 when appendant to claim 3 in which said tongue with the profiled surface is in said array of tongues remote from the hook shaped tongue.

6. A frame as claimed in any one of the preceding claims in which the locking means comprises a bore which extends transversely through the further wall portion and a further bore which extends transversely through the or a tongue, said bores and further bores coinciding when the frame is assembled for a locking component, such as a pin or seal, to be inserted transversely through coinciding bores.

7. A frame as claimed in any one of the preceding claims in which the locking means comprises a latch member carried by and displaceable relative to one of the first and further wall portions and a lug carried by the other of said wall portions, said latch member being displaceable to displace a wall thereof transversely to the plane of the wall portions adjacent to said co-operating tongue and pocket, said wall of the latch member being displaceable to engage the lug when the frame is assembled and thereby retain together the first and further wall portions.

a. A frame as claimed in claim 7 in which the latch member is mounted on the wall portion which carries it for pivotal movement about an axis which is substantially in the plane of that wall portion, said latch member being displaceable by pivotal movement to an engage condition in which its wall engages the lug and a disengage condition in which its wall is clear of the lug for separation of the two frame parts.

9. A frame as claimed in claim 8 which when assembled provides a split line between the respective first wall portion and the further wall portion and over which split line the or each tongue extends into its respective pocket and wherein the pivotal axis extends substantially parallel with the split line formed between the wall portions which the engaging latch member and lug retain together.

10. A frame as claimed in any one of claims 7 to 9 in which the latch member is located in a recess in the wall portion which carries it substantially to be in the plane of that wall portion.

11. A frame as claimed in any one of claims 7 to 10 in which said wall of the latch member includes a recess which receives a neck of the lug when the latch member engages the lug so that a head on the neck of the lug is captured by the latch member to retain the frame parts together.

12. A frame as claimed in claim 11 in which the head of the lug provides a tapered lead-in surface for engaging with the latch member when the frame parts are assembled together whilst the latch member is in a condition in which it is intended to engage with the lug.

13. A frame as claimed in any one of claims 7 to 12 and comprising means restraining displacement of the latch member between a condition in which it is intended to engage the lug and a condition in which it is clear of the lug for separation of the two frame parts and which restraining means is overcome by manual pressure applied to the latch member.

14. A frame as claimed in claim 13 in which the restraining means comprises an abutment with which the latch member engages and which abutment is overcome by flexure.

15. A frame as claimed in claim 14 when appendant to claim 8 in which pivotal movement of the latch member between its engage and disengage conditions causes that member to move over said abutment by manual pressure applied to effect said pivotal movement.

16. A frame as claimed in any one of claims 7 to 15 in which the latch member engages with the lug through surfaces which co-operate with each other to provide a reaction in response to a force tending to separate the two frame parts and which reaction serves to intensify the engagement of the latch member with the lug.

17. A frame as claimed in any one of the preceding claims in which said locking means is a primary locking means and a secondary -locking means is provided which is adjustable to a position in which it retains the primary locking means in a condition in which it retains together the adjacent first and further wall portions.

18. A frame as claimed in claim 17 in which the secondary locking means is actuated in a direction which is transverse to the direction in which the primary locking means is actuated.

19. A frame as claimed in either claim 17 or claim 18 when appendant to claim 8 in which the secondary locking means comprises a catch member which is carried by and displaceable relative to the latch member to a condition in which it restrains the latch member from pivotal movement from its engage condition.

20. A frame as claimed in claim 19 in which the catch member is displaceable relative to the latch member whilst the latch member is in its engage condition for the catch member to engage with the lug and thereby prevent the latch member from being pivoted from its engage condition to its disengage condition.

21. A frame as claimed in any one of the preceding claims and of substantially parallelopipedon shape when assembled and in which each frame part consists of an end wall portion and two opposed side wall portions hingedly connected to the end wall portion, said opposed side wall portions of a frame part forming said first wall portion and said further wall portion.

22. A frame as claimed in claim 21 in which each frame part is collapsible by hinged movement of the side wall portions on the end wall portion to a condition in which one of the side wall portions overlies the end wall portion and is sandwiched between that end wall portion and the other side wall portion.

23. A frame as claimed in either claim 21 or claim 22 in which the end wall portion is of substantially U-shape to present two opposed stub walls and said side wall portions are hingedly connected one to each of the stub walls.

24. A frame as claimed in any one of claims 1 to 20 and of substantially parallelopipedon shape when assembled and in which each frame part consists of an end wall portion and a side wall portion, the end wall portion being of substantially U-shape to present two opposed stub walls, said side wall portion being hingedly connected to one of the stub walls and forming one of said first wall portion and said further wall portion and the other of the stub walls forming the other of said first wall portion and said further wall portion.

25. A frame as claimed in claim 24 in which each frame part is collapsible to a condition in which the side wall portion overlies the end wall portion.

26. A frame as claimed in any one of claims 23 to 25 in which each side wall portion is hingedly connected to the respective stub wall so that when the frame is assembled the side wall portions overlap with parts of the stub walls to which they are respectively hingedly connected so that such hingedly connected side wall portions can abut through the overlap in response to forces on the side wall portions applied in a direction perpendicular to the plane of those wall portions.

27. A container comprising the combination of a frame as claimed in any one of the preceding claims and a base to which the frame is fitted to provide upstanding side walls for the container.

28. A container as claimed in claim 27 in which bottom edges of the frame are profiled to engage with the base for restraining relative displacement horizontally between the base and frame.

29. A container as claimed in either claim 27 or claim 28 and comprising a lid fitted to the frame for closing an open top presented by the frame.

30. A container as claimed in claim 29 in which upper edges of the frame are profiled to engage with the lid for restraining relative displacement horizontally between the lid and frame.

31. A container as claimed in any one of claims 27 to 30 and comprising at least two identical frames stacked vertically on the base and wherein retaining means is provided on the frames for restraining relative displacement horizontally between adjacent frames in the stack.

32. A frame substantially as herein described with reference to the accompanying illustrative drawings.

33. A container comprising a frame as claimed in claim 32 and substantially as herein described with reference to the accompanying illustrative drawings.

34. A frame part for a frame as claimed in any one of claims 1 to 26 and claim 32.