WO2013014462A1

WO2013014462A1 - Improvements relating to packaging

Info

Publication number: WO2013014462A1
Application number: PCT/GB2012/051810
Authority: WO
Inventors: Tim Clarke
Original assignee: Duff Design Limited
Priority date: 2011-07-26
Filing date: 2012-07-26
Publication date: 2013-01-31
Also published as: GB201112862D0

Abstract

A child resistant package comprises a support for supporting hazardous material and a structure for selectively blocking access to the hazardous material. The structure comprises opposed major faces connected by opposed minor side walls, and the support comprises side walls facing the side walls of the structure. The support is movable with respect to the structure in an access direction that is generally aligned with the side walls. The package further comprises an engagement mechanism having an enabled mode and a disabled mode, the engagement mechanism comprising a latch member. In the enabled mode, the latch member is movable in a latch direction between an engaged state, in which the latch acts between the side walls of the support and the structure to prevent movement of the support relative to the structure in the access direction, and a disengaged state, in which movement of the support in the access direction is permitted. The latch path intersects the access direction and extends between the opposed major faces of the structure. In the disabled mode, a barrier member prevents the latch member from acting between the side walls of the support and the structure, such that the latch member is prevented from adopting the engaged state.

Description

Improvements relating to packaging

This invention relates to packaging such as a box, which may be used in the packaging of items. In particular, though not exclusively, the invention relates to a child-resistant package for storing hazardous materials such as, for example, pharmaceuticals or household chemicals, which must be kept safe from children or irresponsible adults. The safe storage of hazardous materials such as pharmaceuticals and household chemicals has long been a problem for families with young children. Whilst parents desire ready access to pharmaceuticals to treat family illness promptly and easily, and require household chemicals to keep their home clean, the natural curiosity of children can cause them to seek out and ingest such materials when unsupervised. This can have serious consequences; for example, an overdose of a pharmaceutical may be injurious to health. Indeed some pharmaceuticals are entirely unsuitable for children and will have an adverse effect on their health even if handled or ingested in very small quantities. Similar dangers arise from other, non-pharmaceutical materials, including household chemicals such as bleach and rat poison.

The problems described above are not limited to children and can also arise in respect of irresponsible or forgetful adults, such as for example mentally ill or mentally disabled patients, or adults with a low mental age, or the elderly who may be prone to confusion as to the contents of a package. Whilst the focus of this specification is on children, it will be appreciated that the majority of what is described herein applies analogously to irresponsible or forgetful adults. All such analogies are within the scope of this specification unless the context requires otherwise, even where reference is made only to children. In light of their dangerous nature, hazardous materials must be kept out of the reach of children. This is an established practice that is of fundamental importance and which may be augmented, but can never be replaced, by child-resistant closures (CRCs). CRCs make it harder for children to extract hazardous materials from a package, if they ever manage to gain access to them in packaged form.

Many CRC designs have been suggested in the past. However, designers of CRCs must always work against the paradox that a package that is difficult for a child to open often also presents difficulties for adults. In fact, up to 90 per cent of adults struggle to open CRCs, according to a 2004 report in the journal of the Engineering and Physical Sciences Research Council. The alarming consequence of this is that adults often decant hazardous materials into containers that lack child-resistant closures and that may, indeed, be confused by children with containers for safe-to- eat items such as sweets - a practice that is thought to contribute to a large proportion of accidental poisonings.

A further problem is that known CRCs are often complicated in structure, and expensive to manufacture. Since the cost of packaging is generally passed on to consumers, this leads consumers to buy products in packaging without child-resistant closures where available, thereby increasing the risk of accidental poisonings or other injuries. The Applicant's previous International patent application published as

WO2009/024772 discloses child-resistant packages that address these problems. Its content is incorporated into this specification by reference.

The inventors have appreciated that whilst child-resistant capability is desirable in a package containing hazardous materials, child resistance may not be required in all circumstances. For example, a user or a vendor of a package containing hazardous materials may judge that there is no real risk of children gaining access to the package. An example is where a user is an elderly person, lacking dexterity, who lives alone and will consume pharmaceuticals in a package over a short period of time. In that case, the needs of the user outweigh the minimal risk of children ever accessing the pharmaceuticals, and so it may be preferred to supply the

pharmaceuticals in a package without child resistance that is as easy as possible for the user to open. However, there will of course be other instances in which child resistance is essential, for example where pharmaceuticals are being supplied to a household having children.

At present, the only way in which these conflicting requirements can be satisfied would be to supply hazardous materials such as pharmaceuticals in two different types of package - one with child resistance and the other without. This would be impractical and inefficient. The alternative of supplying hazardous materials in one type of package requires that package to have some degree of child resistance, which therefore compromises its usability for adults who lack dexterity. If the package is made easier for such adults to open, then its child-resistant properties may be compromised instead.

It is against this background that the present invention has been devised.

A package of the invention has an enabled mode in which it functions

advantageously and effectively as a child-resistant package, for example in a manner largely as described as in the Applicant's previous International patent application published as WO2009/024772. Furthermore, and in contrast to known packages such as described in WO2009/024772, a package of the invention also has a disabled mode, in which its child-resistance is eliminated or suspended. Preferably, a package of the invention can be placed in or returned to the enabled mode after being in the disabled mode.

The present invention broadly resides in a child-resistant package, comprising a support for supporting hazardous material and a structure for selectively blocking access to the hazardous material, the structure comprising opposed major faces connected by opposed minor side walls, the support also comprising side walls facing the side walls of the structure, and the support being movable with respect to the structure in an access direction that is generally aligned with the side walls; the package further comprising an engagement mechanism having an enabled mode and a disabled mode, the engagement mechanism comprising a latch member; wherein, in the enabled mode, the latch member is movable in a latch direction between an engaged state, in which the latch acts between the side walls of the support and the structure to prevent movement of the support relative to the structure in the access direction, and a disengaged state, in which movement of the support in the access direction is permitted, the latch direction intersecting the access direction and extending between the opposed major faces of the structure; and wherein, in the disabled mode, a barrier member prevents the latch member from acting between the side walls of the support and the structure, such that the latch member is prevented from adopting the engaged state. The package of the invention facilitates operation and access for users, e.g. adults having conditions inhibiting dexterity or problems with eyesight, when the

engagement mechanism of the package is in the disabled mode, since the engagement mechanism is then prevented from assuming the engaged state, allowing the package to be brought into the access position with ease. By contrast, when the engagement mechanism is in the enabled mode, users must select the disengaged state to allow the package to assume the access position, thereby introducing an additional hurdle to access, providing a greater degree of child- resistance than in the disabled mode. Ease of operation and access to the package according to the invention can hence be adjusted between two levels, allowing the package to be adapted to suit a broad range of users. This in turn provides benefits of economy of scale and mass production in manufacture. The latch member acting between the sidewalls of the support and structure provides the package with a particularly effective engagement mechanism. The sidewalls provide engagement surfaces having a larger area than those provided by alternative arrangements, resulting in a greater area that resists movement of the support. The package is therefore particularly difficult to force open, for example by applying excessive force to the support to break the engagement mechanism, when the latches are engaged.

The latch direction intersecting the access direction and extending between the opposed major faces means that, in order to operate the package, the user must depress the latch member in a direction that differs from the access direction. The difference between the latch direction and the access direction makes operation of the package more surprising, thereby enhancing child resistance.

The invention also resides in a child resistant package comprising: a support for supporting hazardous material in use; a structure for selectively blocking access to the hazardous material, the support and the structure being movable relative to each other between a secured position in which access to the hazardous material is blocked by the structure and an access position in which the hazardous material is accessibly clear of the structure; and an engagement mechanism comprising at least one latch member that, in an enabled mode of the mechanism, is movable by a user between an engaged state in which relative movement between the support and the structure from the secured position is prevented, and a disengaged state in which relative movement between the support and the structure out of the secured position into the access position can occur, the latch member assuming the engaged state when the package is in the secured position and the engagement mechanism is in the enabled mode; wherein the engagement mechanism has a disabled mode in which the latch member is prevented from assuming the engaged state.

The invention extends to a method of enabling or restricting access to hazardous material held in a child-resistant package, the package comprising: a support for supporting hazardous material, and a structure for selectively blocking access to the hazardous material, the structure comprising opposed major faces connected by opposed minor side walls, the support comprising side walls facing the side walls of the structure, and the support being movable with respect to the structure in an access direction that is generally aligned with the side walls; and an engagement mechanism comprising a latch member with child-resistant functionality capable of acting between the side wall of the support and the side wall of the structure to prevent relative movement between the support and the structure necessary for access to that hazardous material, and moveable in a latch direction intersecting the access direction and extending between the opposed major faces of the structure; wherein the method comprises positioning a barrier member in the engagement mechanism to prevent the latch from acting between the sidewalls of the support and the structure, so as to disable the child-resistant functionality of the engagement mechanism.

The invention also extends to a method of enabling or restricting access to hazardous material held in a child-resistant package, the package comprising: a support for holding the hazardous material; a structure for selectively blocking access to that hazardous material; and an engagement mechanism with child-resistant functionality for preventing relative movement between the support and the structure necessary for access to that hazardous material; wherein the method comprises selectively disabling the child-resistant functionality of the engagement mechanism.

Other optional and advantageous features of the invention are set out in the appended claims. These and other preferred features and advantages of the invention will be apparent to the skilled person from the following specific description of preferred embodiments.

In order that the invention may be more readily understood, reference will now be made, by way of example, to the accompanying drawings in which:

Figure 1 is an exploded perspective view of a child-resistant package for pharmaceuticals in a first embodiment of the invention having one blister pack;

Figure 2 is a top perspective view of the package of Figure 1 , when assembled and in a closed state;

Figure 3 is a top perspective view of the package of Figure 2 but in an open state;

Figures 4a to 4c are sectional views on a horizontal plane through the package of Figures 2 and 3, showing in sequence the child-resistant operations necessary to release the package from the closed state for opening; Figure 5 is a bottom perspective view of the package of Figure 3, still in the open state; Figures 6a to 6e are bottom perspective views of the package corresponding to Figure 5, showing in sequence the use of shims carried by the package to disable and re-enable child resistance of the package;

Figures 7a and 7b are sectional views on a horizontal plane corresponding to that of Figures 4a to 4c, showing in sequence the effect of the shims, and Figure 7c is an enlarged sectional view of a detail of Figure 7a;

Figure 8 is an exploded perspective view of a child-resistant package for pharmaceuticals in a second embodiment of the invention having two blister packs;

Figure 9 is a top perspective view of the package of Figure 8, when assembled and in a closed state;

Figure 10 is a top perspective view of the package of Figure 9 but in an open state;

Figure 1 1 is a bottom perspective view of the package of Figure 10, still in the open state; and

Figures 12a to 12f are bottom perspective views of the package

corresponding to Figure 1 1 , showing in sequence the use of shims carried by the package to disable and re-enable child resistance of the package.

Referring firstly to Figures 1 to 7c, in a first embodiment of the invention a child- resistant package 100 comprises: a drawer-like storage tray 200 for storing hazardous materials, in this case pharmaceuticals 102; a tab member 300 for moving the storage tray 200 between closed 204 and open positions 306 via a band-drive mechanism 400; a hollow case 500 for blocking access to the hazardous materials when the storage tray 200 is in the closed position 204; and an engagement mechanism 600 including latch members 308, 310 acting between the storage tray 200 and the case 500 to impart child resistance to the package 100.

In accordance with the invention, the engagement mechanism 600 can adopt enabled and disabled modes. The disabled mode eliminates, suspends or at least substantially reduces the child-resistance of the package to the benefit of its ease of opening by responsible adults who lack dexterity.

The structure of the package is based in part on principles and structural features described in the Applicant's previous International patent application published as WO2009/024772. However, modifications have been made to provide the additional dual-mode functionality of the invention, which enables and disables the child resistance of the package when required. The case 500 comprises upper 1 12 and lower shells 1 14 of injection-moulded plastics material that are generally oblong in plan; they have parallel side walls 1 18, 120, 122, 124 on long sides 226, 228 of the oblong and one end wall 130, 132 on a short side 231 , 233 of the oblong. The side walls 1 18, 120, 122, 124 of the shells 1 12, 1 14 abut when the shells 1 12, 1 14 are brought together, and the shells 1 12, 1 14 are attached to each other along their abutting side walls 1 18, 120, 122, 124 by any suitable means such as a snap-fit, by adhesive or by welding. The end walls 130, 132 of the shells do not abut, as they are at opposite ends of the case 500; this leaves openings 134, 136 at each end 138, 140 of the case 500 through which the storage tray 200 and the tab member 300 can move in and out of the case 500, between the closed state 204 shown in Figure 2 and the open state 306 shown in Figure 3.

The side walls 122, 124 of the lower shell 1 14 have central oblong cut-outs 142, 144. Each cut-out 142, 144 is aligned with a cantilevered push-button 146, 148 depending from a side wall 1 18, 120 of the upper shell 1 12. The cut-outs 142, 144

accommodate the push-buttons 146, 148 when the shells 1 12, 1 14 are brought together and allow for inward resilient movement of the push-buttons 146, 148 when a user squeezes together the sides 226, 228 of the case 500 in alignment with the push-buttons 146, 148. When released, the push-buttons 146, 148 are urged outwardly by their resilience to lie substantially flush with the side walls 122, 124 of the lower shell 1 14. An overlap 450, 452 between the push-button 146, 148 and the adjacent side wall 122, 124 helps to prevent the push-button 146, 148 being pulled out by a child intent on fiddling with the mechanism. The push-buttons 146, 148 are of thinner cross-section than the side walls 122, 124 of the lower shell 1 14, which leaves a gap 454, 456 behind the push-buttons 146, 148 to give clearance for their inward movement when pressed. The thinner cross- section of the push-buttons also leaves corner formations 458, 460 on the inner side walls 462, 464 of the lower shell 1 14 at the forward edges 466, 468 of the cut-outs 142, 144, inward of the push-buttons. As will be described, latch members 308, 310 extend into the gap 454, 456 behind the push-buttons 146, 148 to engage these corner formations 458, 460, which prevents the storage tray 200 being withdrawn from the case 500 unless the push-buttons146, 148 are depressed to disengage the latch members 308, 310 from the corner formations 458, 460.

When brought together, the shells 1 12, 1 14 sandwich a divider 170 that is located by rebates 172, 174 extending along the side walls 122, 124. The divider 170 separates the interior of the case into an upper volume 376 for housing the tab member and a lower volume 378 for housing the storage tray. The upper 376 and lower volumes 378 are not through-passages but are each closed at one end - the front 180 and rear end 182 respectively, by respective end walls 130, 132 of the shells.

The divider 170 supports an endless band 184, to which the storage tray 200 and the tab member 300 are attached by transverse adhesive strips 186, 188. Thus, the band 184 supported by the divider 170 links opposed sliding movement of the storage tray 200 and the tab member 300 as described in our European patent published as EP1 140639. The band 184 is typically a strip of a low-friction sheet material such as plastics film, e.g. polypropylene sold under the trade mark Treofan GND, and runs longitudinally on both surfaces of the divider 170, sliding around forward-facing and rearward-facing edges 190, 192 of the divider 170. Thus, the band 184 moves around the divider along a longitudinal band path.

The structure of the storage tray 200 is broadly similar to that described with reference to Figures 14A and 14B in WO2009/024772. The storage tray 200 comprises a generally oblong injection-moulded plastics frame 1 16. The frame 1 16 has left and right lateral walls 194, 196 joining a front wall and a rear wall 198, 201 . A flange 203 projects inwardly from the walls in a plane disposed at a lower side 205 of the frame. Parallel struts 207, 209 disposed in the plane 205 of the flange 203 extend longitudinally from the flange 203 at the front wall 198 to the flange 203 at the rear wall 201 , defining three oblong parallel apertures 21 1 , 213, 215 between themselves and the surrounding flange 203.

The frame 1 16 supports a largely conventional generally oblong blister pack 217 that provides storage for pharmaceutical products 102 such as tablets or capsules (not shown) within a plurality of blisters 219 arranged in this example in three parallel rows 221 , 223, 225. The blister pack 217 comprises an upper blistered side 227 of flexible and preferably transparent plastics and a lower, foil-covered side 529 that seals pharmaceutical products in the blisters 219. The lower side 529 of the blister pack 217 is bonded or otherwise engaged to the frame 200 atop the flange 203 and the struts 207, 209, with the blisters 219 of the blister pack 217 projecting upwardly and aligned in rows 221 , 223, 225 with the apertures 21 1 , 213, 215 in the frame 1 16. A product (not shown) within a blister 219 may be accessed in conventional fashion by pressing the blister 219 down to force the product through the foil covering of the lower side 529 of the blister pack 217, with access to the product (not shown) being available through the corresponding aperture 21 1 , 213, 215 in the frame 1 16.

The frame 1 16 of the storage tray 200 comprises left and right latch members 308, 310 forming part of the engagement mechanism 600 of the package 100. The frame 1 16 is symmetrical about a central longitudinal plane; consequently, the left and right latch members 308, 310 are mirror images of each other and they function identically but move in opposite directions. Each latch member 308, 310 is defined by a respective cut-out 235, 237 in the flange 203 of the frame 1 16. Specifically, the cutouts 235, 237 define, and provide clearance for inward movement of, left and right movable sections 239, 241 of the flexible left and right lateral walls 194, 196 of the frame 1 16 respectively. Each movable section 239, 241 comprises a respective integral engagement formation 243, 245 that forms part of a latch member 308, 310, supported by live hinges 247, 249. The engagement formations 243, 245 align with the cut-outs 235, 237 and pushbuttons 146, 148 of the case 500 when the storage tray 200 is in the closed position 204 within the case 500, such that the push-buttons 146, 148 act on the engagement formations 243, 245 when pressed inwardly by a user. The engagement formations 243, 245 each comprise a ramp 451 , 453 and an opposed forwardly-facing shoulder 455, 457 and are located substantially centrally between the front and rear ends 198, 201 of the storage tray 200. Each shoulder 455, 457 extends substantially orthogonally from the front section 122a, 124a of the respective lateral wall 122, 124 of the frame 1 16. The engagement formations 243, 245 are naturally and resiliency biased outwards by the live hinges 247, 249, so that the engagement formations 243, 245 project laterally beyond respective remaining rear 122b, 124b and front sections 122a, 124a of the left and right lateral walls 122, 124 of the frame 1 16.

The engagement formations 243, 245 of the latch members 308, 310 are each resiliency movable between a latched or engaged state and an unlatched or disengaged state. Details of the engaged and disengaged states will now be described with reference to Figures 4a to 4c.

By default, the natural flexibility and resilience of the live hinges 247, 249 biases the engagement formations 243, 245 of the latch members 308, 310 outwardly into their latched or engaged state, which is shown in Figure 4a. In that state, the engagement formations 243, 245 protrude laterally beyond the remaining rear 122b, 124b and front sections 122a, 124a of the respective lateral walls 122, 124 of the storage tray 200, with the shoulder 455, 457 facing forwards. The shoulder 455, 457 of the engagement formation 243, 245 thus forms a step or protrusion 459, 461 , which extends into the gap 454, 456 behind a push-button 146, 148 to engage a complementary opposed corner formation 458, 460 of the case 500, which engagement prevents movement of the storage tray 200 out of the case 500. By pressing the push-buttons 146, 148 of the case 500, a user may press the engagement formations 243, 245 of the latch members 308, 310 inwardly, i.e.

towards the inside of the storage tray 200 against the bias of the live hinges 247, 249. When the engagement formations 243, 245 of the latch members 308, 310 are pressed inwardly by the push-buttons 146, 148 in this way, the latch members 308, 310 assume their unlatched state as shown in Figure 4b. In the unlatched state, the engagement formations 243, 245 lie substantially flush with the neighbouring front and rear sections 122a, 124a, 122b, 124b of the respective lateral walls 122, 124 of the storage tray 200, such that the shoulders 455, 457 are accommodated within the generally oblong periphery of the tray 200. The shoulders 455, 457 of the

engagement formations 243, 245 therefore disengage from the opposed corner formations 458, 460 of the case 500. In the unlatched state, the shoulders 455, 457 of the engagement formations 243, 245 thus no longer form a step or protrusion 459, 461 that prevents movement of the storage tray 200 out of the case 500. It is now possible for the storage tray 200 to be moved out of the case 500 as shown in Figure 4c, by pulling the tab member 300 out of the case 500 in the opposite direction to move the band 184 around the divider 170. It will be noted that the storage tray 200 and the upper and lower shells 1 12, 1 14 of the case 500 have thumb recesses 163a, 163b at one end 138 to enable a user to grip and pull an end of the tab member 300 when the package 100 is closed 204. In summary, the left and right latch members 308, 310 may each be moved independently by the push-buttons 146, 148 between a latched state in which the shoulders 455, 457 of their engagement formations 243, 245 protrude laterally, and an unlatched state in which those shoulders 455, 457 lie substantially flush with the lateral walls 194, 196 of the frame 1 16 of the storage tray 200.

The tab member 300 comprises an oblong panel of injection-moulded plastics material that carries a leaflet 165 in a shallow tray formation 167 on its upper side 169 to provide information to users concerning the pharmaceutical products in the blister pack of the storage tray. The tab member 300 also carries integrally-moulded snap-out shims 171 , 173 on its forward edge 175 that are used as barrier members 877, 879 to disable the engagement mechanism 600, in a manner that will now be described.

On the lower side of the case 581 , the push-buttons 146, 148 of the upper shell 1 12 stand clear from the lower shell 1 14, leaving a slot 583, 585 aligned with each cut-out 235, 237 in the lower shell 1 14 communicating with the gap 454, 456 behind each push-button 146, 148. These slots 583, 585 accommodate the shims 171 , 173 that are snapped out of the tab member 300 as shown in Figure 6a and inserted into the slots 583, 585 as shown in Figures 6b and 6c. Each shim 171 , 173 is an oblong generally flat and thin tab 687a, 687b having a lip 689a, 689b of greater thickness along its upper or proximal edge 691 a, 691 b. The lip 689a, 689b limits insertion of the shim 171 , 173 into a slot 583, 585 and provides a grip for a user's fingernail to withdraw the shim 171 , 173 from the slot 583, 585 as shown in Figures 6d and 6e, to re-enable the engagement mechanism 600.

Figures 7a to 7c show the effect of the shims 171 , 173 when inserted into the slots 583, 585. The shims 171 , 173 then lie inboard of the push-buttons 146, 148 to fill the gaps 454, 456 behind the push-buttons 146, 148 . This prevents the engagement formations 243, 245 of the latch members 308, 310 of the tray 200 engaging with the corner formations 458, 460 of the case, as shown in Figure 7a and in enlarged detail in Figure 7c. The tray 200 may therefore be moved freely out of the case 500 as shown in Figure 7b, without a user needing to depress the push-buttons 146, 148. Child-resistance is therefore disabled when the shims 171 , 173 are inserted into the slots 583, 585. This disabling operation may, for example, be performed by a vending pharmacist on request of a user where children are unlikely to have access to the package.

If the shims 171 , 173 are subsequently removed from the slots 583, 585 as shown in Figures 6d and 6e, the engagement formations 243, 245 of the latch members 308, 310 may again engage with the corner formations 458, 460 of the case 500 when the tray 200 is fully closed 204 within the case 500. This re-enables the child-resistance of the package 100, and so enables a user or a vendor to protect children who may gain access to the package 100.

When the engagement mechanism is in the enabled mode, i.e. when the shims 171 , 173 are not inserted into the slots 583, 585, the package 100 functions

advantageously and effectively as a child-resistant package, as taught in

WO2009/024772. In particular, to provide child resistance, the latch members 308, 310 and the covering push-buttons 146, 148 (alone and in synergy with the band- drive mechanism 400 of the package 100) make it difficult for children to open the package.

Opening movement of the storage tray 200 is only possible when the latch members 308, 310 are simultaneously brought into their unlatched state by a user pressing the push-buttons towards each other, for example in a squeezing action between thumb and forefinger. The tab member 300 must also be pulled simultaneously to drive the band 400 around the divider 170. That movement of the band 400 moves the storage tray 200 out of the case 500.

Once clear of the cut-outs 142, 144 in the case 500, the engagement formations 243, 245 of the latch members 308, 310 are held inwards in the disengaged state by the side walls 122, 124 of the case 500 until they exit the case 500, whereupon they are biased back outwards by the live hinges 247, 249.

When the tab member 300 is pushed back into the case 500, the tab member 300 turns the band 400 around the divider 170, so that the storage tray 200 moves into the case 500 from the opposite side in the opposite direction. If preferred, a user can push the storage tray 200 into the case 500 to close the storage tray 200, which in turn pulls the tab member 300 back into the case 500. The effect is the same, in that both the storage tray 200 and the tab member 300 will return to the secured position 204 shown in Figure 2 in which the storage tray 200 is inaccessibly housed within the case 500. When the storage tray 200 is returned into the case 500 from the open access position 306, the side walls of the case 122, 124 initially push the left and right latch members 308, 310 inwardly into the unlatched state. The ramps 451 , 453 of the engagement formations 243, 245 of the latch members 308, 310 facilitate this inward movement, guiding the latch members 308, 310 into the unlatched state 700c gradually, against the bias of the live hinges 247, 249. When the engagement formations 243, 245 of the latch members 308, 310 reach the associated cut-outs 235, 237 of the case 500, they snap out into the latched state due to the bias of the live hinges 247, 249. Thus the latch members 308, 310 engage in a snap fit with the case 500 when the storage tray 200 is returned fully into the closed position 204 in the case 500.

The push-buttons 146, 148 concealing the latch members 308, 310 provide a first level of child resistance. To open the package, users must initially have an understanding that it is necessary to actuate the push-buttons 146, 148 to move the latch members 308, 310 into the disengaged state. Such understanding is usually absent in young children, particularly if the push-buttons 146, 148 lie flush with the side walls of the case 122, 124.

To help address the paradox that a package that is difficult for a child to open often also presents difficulties for adults, the push-buttons 146, 148 may be marked, for example with letters, and written instructions may be supplied on how to disengage the latch members 308, 310, for example on the case 500 of the package 100. Thus it is possible for the push-buttons 146, 148 to conceal the latch members 308, 310 while still providing an indication to a mature user of where the latch members 308, 310 are located and how they should be disengaged.

Additional child resistance is provided by a synergy between the tab member 300, the band 184, the latch members 308, 310 and the push-buttons 146, 148. Even if a user understands that it is necessary to press the push-buttons 146, 148

simultaneously to open the package 100, the storage tray 200 cannot be opened via the push-buttons 146, 148 alone. Instead, to gain access to the storage tray 200, it is necessary to hold the left and right latch members 308, 310 in the unlatched state 700c with one hand by pressing the push-buttons 146, 148 inwards, and,

simultaneously, to apply an opening force on the tab member 300 at the opposite end of the package 100 with the other hand. The force that is required to access the storage tray 200 is reversed by the band 184, such that an opposite opening force must be applied to the tab member 300 at an opposite end of the package 100 whilst the latch members 308, 310 are

simultaneously disengaged. The need to understand the link between holding the latch members 308, 310 in their disengaged state (via the push-buttons 146, 148) and opposite movement of the tab member 300 with respect to the direction of movement of the storage tray 200 provides additional child resistance.

Figures 8 to 12 show a child-resistant package 700 in a second embodiment of the invention that is similar to the first embodiment in its general structure and function. Like numerals are therefore used for like parts. The second embodiment differs from the first embodiment in the following respects.

Firstly the tab member 300 of the first embodiment is replaced by a second storage tray 200b holding a second blister pack 217b on one side 793 and an information leaflet 165 on the reverse side 795. The two blister packs 217a, 217b in the package 700 of the second embodiment are oriented to face the same way when the package 700 is opened. The information leaflet 165 may be removed from the reverse side 795 of the second storage tray 200b to allow pharmaceutical products (not shown) to be dispensed from the second blister pack.

When released by simultaneously depressing the push-buttons 146, 148 on the case, the second storage tray 200b is pulled from the case in the manner of the tab member 300 of the first embodiment. Again, this drives the other storage tray 200a out of the case in the opposite direction by virtue of the interconnecting band-drive mechanism 400.

In the second embodiment as illustrated, both of the storage trays 200a, 200b have latch members 308a, b; 310a,b whose engagement formations 243a, b; 245a, b have shoulders 455a, b; 457a, b facing in opposite directions to engage with opposite sides 466, 468, 470, 472 of the cut-outs 142, 144 in the case. This provides strong resistance to opening either storage tray 200a, 200b unless the push-buttons 146, 148 are pressed. Elegantly and conveniently, however, each push-button 146, 148 acts on engagement formations 243a, b; 245a, b of both storage trays, which are stacked in alignment with the cut-outs 142, 144 when the package 700 is closed. Consequently, pressing one push-button 146, 148 disengages the engagement formations 243a, b; 245a, b of both storage trays 200a, 200b on that side of the package 700, with no additional movements required of a user in comparison with the first embodiment.

Other variations of the second embodiment over the first embodiment include the position of the shims 771 , 773, which in the second embodiment are moulded integrally with the flange 203 of the first storage tray 200a at a position outboard of the blister pack 217a of that tray as shown in Figures 10, 1 1 and 12a. It will also be noted that the slots 583, 585 of the second embodiment each have a small notch 797, 799 giving better access for a user's fingernail to withdraw a shim 771 , 773 from the slot as shown in Figures 12d and 12e.

Moreover, each shim 771 , 773 in the second embodiment has a hole 802, 804 whereby the shims may be reaffixed to the first storage tray after use. In this example, spigots 806, 808 are provided outboard of the blister pack 217a of the first storage tray 200a, on which the holes 802, 804 of the shims 771 , 773 press-fit as shown in Figure 12f. In this way, the shims 771 , 773 may be kept readily to hand when the engagement mechanism 600 has been re-enabled, to disable the engagement mechanism 600 again if required.

Many variations are possible without departing from the inventive concept. For example, the second embodiment may be modified by providing latch members on only one of the storage trays, and relying upon the band-drive mechanism to lock opening movement of the other storage tray. It would also be possible to provide latch members on only one side of a storage tray; in that case, where there are two storage trays, latch members may be provided on one side of one tray and on the other side of the other tray.

Claims

1 . A child resistant package comprising a support for supporting hazardous material and a structure for selectively blocking access to the hazardous material, the structure comprising opposed major faces connected by opposed minor side walls, the support also comprising side walls facing the side walls of the structure, and the support being movable with respect to the structure in an access direction that is generally aligned with the side walls;

the package further comprising an engagement mechanism having an enabled mode and a disabled mode, the engagement mechanism comprising a latch member;

wherein, in the enabled mode, the latch member is movable in a latch direction between an engaged state, in which the latch acts between the side walls of the support and the structure to prevent movement of the support relative to the structure in the access direction, and a disengaged state, in which movement of the support in the access direction is permitted, the latch direction intersecting the access direction and extending between the opposed major faces of the structure; and

wherein, in the disabled mode, a barrier member prevents the latch member from acting between the side walls of the support and the structure, such that the latch member is prevented from adopting the engaged state.

2. The package of Claim 1 , wherein the package is capable of being placed in or returned to the enabled mode after being in the disabled mode.

3. The package of Claim 1 or Claim 2, wherein, in the disabled mode the barrier member blocks movement of the latch member in the first direction into the engaged state. 4. The package of any preceding claim, wherein the barrier member is a discrete element separate from the engagement mechanism.

5. The package of Claim 4, wherein the barrier member is insertable into the engagement mechanism to block movement of the latch member into the engaged state.

6. The package of Claim 4 or Claim 5, wherein the barrier member is attached to a mounting on the package and is separable from the mounting when used to disable the engagement mechanism. 7. The package of Claim 6, wherein the mounting is on the support.

8. The package of Claim 6 or Claim 7, wherein the barrier member is integral with the mounting before separation from the mounting. 9. The package of any one of Claims 4 to 8, wherein the barrier member is attachable to a mounting on the package after being used to disable the engagement mechanism.

10. The package of any preceding claim, wherein the or each latch member is resiliency biased into the engaged state.

1 1 . The package of any preceding claim, wherein the or each latch member comprises a shoulder for engaging the structure in the engaged state. 12. The package of Claim 1 1 , wherein in the disabled mode, the barrier member prevents the shoulder engaging the structure.

13. The package of Claim 12, wherein the shoulder can engage an edge of an opening or recess in the structure in the enabled mode and the barrier member is positioned in that opening or recess in the disabled mode to prevent the shoulder engaging that edge.

14. The package of any preceding claim, wherein the or each latch member comprises a ramp for guiding the latch member into the disengaged state.

16. The package of any preceding claim, wherein the or each latch member is carried by the support.

17. The package of Claim 16, wherein the or each latch member protrudes beyond an outer wall of the support in the engaged state.

18. The package of Claim 17, wherein, in the disengaged state, the or each latch member lies substantially flush with the outer wall and is accommodated within the support.

19. The package of any preceding claim, wherein the support comprises a storage tray and the structure is a cover for the tray, the tray being movable as a drawer from under the cover.

20. The package of Claim 19, wherein the storage tray comprises a frame for supporting a blister pack and one or more openings within the frame to allow access to the or each blister of the blister pack.

21. The package of any preceding claim, wherein the or each latch member is carried by a side wall of the storage tray. 22. The package of Claim 21 , wherein the or each latch member projects beyond the associated wall in the engaged state to form a protrusion.

23. The package of Claim 21 or Claim 22, wherein the or each latch member lies substantially flush with the associated wall in the disengaged state.

24. The package of any preceding claim, wherein the structure has at least one pushbutton co-operable with an associated latch member in the secured position for movement of the associated latch member between the engaged state and the disengaged state.

25. The package of Claim 24, wherein co-operation of the push-button with the associated latch member involves elastic deformation of the structure.

26. The package of Claim 24 or Claim 25 when depending directly or indirectly from Claim 3, wherein in the disabled mode, the barrier member lies between the push button and the associated latch member.

27. The package of Claim 26, wherein the structure defines a clearance behind the push-button for inward movement of the push-button, and a slot in the structure communicates with that clearance for insertion of the barrier member to select the disabled mode.

28. The package of any of Claims 24 to 27 and having an overlap between a pushbutton and a neighbouring wall of the structure to resist outward movement of the push-button beyond that wall. 29. The package of any preceding claim and being adapted for two-handed operation by a user, wherein the support is movable by one hand of the user when the or each latch member has been moved into the disengaged state by the user's other hand.

30. The package of any preceding claim, wherein first and second latch members are adapted to be movable from their engaged state into their disengaged state in a squeezing action between a thumb and forefinger of a user.

31. The package of any preceding claim, further comprising a tab member movable by the user with respect to the structure, the tab member being coupled to the support to effect movement of the support out of the secured position when the or each latch member is in the disengaged state.

32. The package of Claim 31 when depending directly or indirectly from Claim 6, wherein the mounting for the barrier member is on the tab member.

33. The package of Claim 31 or Claim 32 and being adapted for two-handed operation by a user, wherein the tab member is movable by one hand of the user when the or each latch member has been moved into the disengaged state by the user's other hand.

34. The package of any preceding claim, wherein the tab member is movable away from the structure to effect movement of the support away from the structure in an opposite direction. 35. The package of Claim 34, wherein the structure defines opposed ends and the tab member is movable away from one end of the structure to cause the support to move away from the opposite end of the structure.

36. The package of any of Claims 31 to 35, wherein the or each latch member is to one side of the structure, opposed to a grip of the tab member.

37. The package of any of Claims 31 to 36, wherein the tab member is coupled to the support by a belt, the belt extending around a divider of the structure. 38. The package of any preceding claim, wherein the disabled mode of the engagement mechanism is not selectable when the latch member is in the engaged state.

39. The package of Claim 5, or any one of Claims 6 to 38 when depending directly or indirectly from Claim 5, wherein the latch direction is intersected by an insertion path of the barrier member.

40. The package of claim 39, wherein the insertion path is defined by a slot provided in the structure.

41 . The package of claim 40 wherein the slot is provided between a major face and a side wall of the structure.

42. A method of enabling or restricting access to hazardous material held in a child- resistant package, the package comprising:

a support for supporting hazardous material, and a structure for selectively blocking access to the hazardous material, the structure comprising opposed major faces connected by opposed minor side walls, the support comprising side walls facing the side walls of the structure, and the support being movable with respect to the structure in an access direction that is generally aligned with the side walls; and an engagement mechanism comprising a latch member with child-resistant functionality capable of acting between the side wall of the support and the side wall of the structure to prevent relative movement between the support and the structure necessary for access to that hazardous material, and moveable in a latch direction intersecting the access direction and extending between the opposed major faces of the structure;

wherein the method comprises positioning a barrier member in the

engagement mechanism to prevent the latch from acting between the sidewalls of the support and the structure, so as to disable the child-resistant functionality of the engagement mechanism.

43. The method of Claim 42, wherein the child-resistant functionality of the engagement mechanism is disabled before sale or supply of the package to a user.

44. The method of Claim 42 or Claim 43 and further comprising enabling or subsequently re-enabling the child-resistant functionality of the engagement mechanism.

45. The method of Claim 44, wherein the child-resistant functionality of the engagement mechanism is enabled before sale or supply of the package to a user or re-enabled after sale or supply of the package to a user.

46. The method of any of Claims 42 to 45, wherein the child-resistant functionality of the engagement mechanism may be disabled only after relative movement between the support and the structure giving access to the hazardous material.