GB2186315A - Sliding-door latch - Google Patents

Abstract

A fowl/poultry crate or other container has an opening closed by a slidable door (6) formed centrally along one transverse edge with a recess (10) in which a latch (9) is installed. The latch (9) includes a resilient tongue (15) with a hook (18) at one end. The hook (18) can be urged into latching engagement with an abutment at one edge of the door opening by resilient deflection of an inclined surface (23), so that the hook (18) subsequently latches over the abutment. Manual pressure upon the lower (in Fig. 5) surface of the tongue (15) will deflect the hook (18) and allow the door (6) to be slid to a fully open position which is limited by a stop (19). The construction and arrangement are such that the latch (9) remains wholly within the thickness of the wall panel of which, during use, the door (6) forms a part so that, whilst being readily manually releasable, the closure (9) will not be accidently unfastened merely by, for example, a heavy article being placed on top of the crate or other container. <IMAGE>

Description

SPECIFICATION Container closures This invention relates to the releasable closure of containers and is particularly, but not exclusively, applicable to a closure for the slidable door of a synthetic plastics cage-like poultry crate that may be employed in temporarily housing chickens or other fowls during the live transport thereof.

A poultry crate of the kind which may advantageously be provided with a closure in accordance with the invention is formed from polyethylene or some other strong but readily mouldable synthetic plastics material and has a rectangular floor panel, two longer side walls, two shorter side walls and a top panel, all six of which panels are of rectangular lattice work construction giving many square or oblong openings whose maximum widths are preferably not greater than about 30 to 60 mms, the wall height and the floor panel area being such that several chickens or other fowls can occupy the crate without discomfort for the duration of a journey on a road vehicle and/ora railway train or even an aircraft.The synthetic plastics construction and the open-work formation of such a crate make it particularly easy to keep clean by washing using, for example, merely a jet of water from a hosepipe.

The top panel of a crate of the kind briefly described has a slidable door through which, when opened, poultry may be introduced into, and withdrawn from, the interior of the crate. It is necessary that the door should have a simple but effective closure which can easily be released when required but that will not otherwise become unlatched as a result of a mechanical shock or like event.

According to the invention, there is provided a releasable closure for the door of a container which co-operates slidably with an opening in a wall panel of that container, said closure comprising a resiliently deflectable tongue carried by said door and shaped latchinglyto engage an abutment at one edge of said opening, the tongue being releasable from such latching engagement by manually depressing a readily accessible portion thereof and said tongue being constructed and arranged so as always to be located wholly within the overall thickness of the wall panel that is formed with said opening.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a top prospective view of a synthetic plastics poultry crate comprising a releasable closure in accordance with the invention, the slidable door in the top panel of the crate being omitted so that the opening with which that door cooperates is shown in an open condition, Figure 2 is a plan view, to a considerably enlarged scale, of the slidable door of the crate of Figure 1, Figure 3 is a plan view, to a further enlarged scale, of a closure plate which is fitted in a recess of the door of Figure 2, Figure 4 is an underneath plan view corresponding to Figure 3, Figure 5 is an inverted side elevation corresponding to Figure 4, and Figure 6 is a section taken on the line VI--VI in Figure 2.

Referring to the accompanying drawings, Figure 1 illustrates a synthetic plastics poultry crate comprising a rectangular floor panel that cannot be seen in Figure 1,two longer side walls 1,two shorter side walls 2 and a top panel 3. The crate is formed throughout from a strong but readily mouldable synthetic plastics material such as polyethylene, polystyrene or polyvinyl chloride but other synthetic plastics materials may be used, if desired, and it is not essential that all parts of the crate should be formed from the same material. It will be seen from Figure 1 that each of the six panels of the crate is of lattice work construction giving many square or oblong openings whose maximum widths are preferably not greater than about 60 mms but whose maximum lengths may be larger.Generally speaking,the side walls 1 and 2 are provided with upright oblong openings of greater dimensions than the openings in the floor panel and top panel 3. In any case, the height of the walls 1 and 2 and the area of the floor panel are such that several chickens or other fowls can occupy the crate without discomfort during live transport on a road vehicle and/or a railwaytrain or even an aircraft, the strength and open-work construction of the crate being such that a number of the crates can be stacked one on top of the other and several piles of crates can be arranged alongside one another without any danger of suffocation to the livestock contained therein.The synthetic plastics construction and the open-work formation also have the considerable advantage that the crate is particularly easy to keep clean by washing using, for example, merely a jet of water from a hosepipe. There are no ferrous metal parts to deteriorate by becoming rusty however many times such a washing treatment is repeated. The synthetic plastics materials may be brightly coloured and, if desired, crates of contrasting colours may be produced so that, purely for example, yellow crates may be employed for chickens, green ones for ducks, blue ones for pigeons and so on. Handling of the crates is facilitated by forming hand slots 4 in the opposite upright shorter side walls 2 of each crate.

Fowls are introduced into, and are withdrawn from, the interior of the crate through an access opening 5 formed approximately centrally of the top panel 3 of the crate. This access opening 5 is closed by a slidable door 6 that can be seen in Figures 2 and 6 of the drawings. The opposite edges of the access opening 5 are formed with parallel, recessed tracks 7 and ribs 8 at the opposite parallel edges of the slidable door 6 are entered in those tracks 7 so as to be readily slidable therealong.

It is important that the slidable door 6 should have a simple but effective closure which can easily be released when required but that will not otherwise become unlatched as a result of a mechanical shock of like event which might occur if, for example, one of the crates were to be dropped during handling.

To this end, an initially separate synthetic plastics closure plate 9 that is illustrated in Figures 3,4 and 5 of the drawings is fitted in a recess 10 formed centrally along one transverse edge of the slidable door 6. The recess 10 exhibits a top plate 11 formed with two spaced but parallel transverse strengthening ribs 12 and, beneath those ribs 12, two projections 13 are directed towards one another from opposite sides of the recess 10. Two ribs 14 of the synthetic plastics lattice of the slidable door 6 extend short distances into the recess 10 at the inner end of the latter, said ribs 14 being integrally secured to one wall of the recess 10 and to the top plate 11 of that recess.

The closure plate 9 is formed from a strong synthetic plastics material which has some resiliency and that may conveniently, but not essentially, be the same synthetic plastics material from which all, or at least part, of the remainder of the crate is made. However, advantageously, it is of a different colour to the rest of the crate so as to enable it quickly and easily to be visually located.

The plate 9 has a substantially flat top and, at one end, integrally extends into a reduced width tongue 15 flanked at opposite sides by two parallel fingers 16 that are spaced by short distances from the respective outer edges of the tongue 15. It will be noted from Figure 5 of the drawings that the tongue 15 is of reduced thickness as compared with the major portion of the closure plate 9, to give that tongue 15 a significant degree of resiliency, but that the fingers 16 by which it is flanked have the same thickness as does said major portion of the closure plate 9 and therefore only a limited degree of resiliency. Three inclined buttresses 17 strengthingly interconnect the root end of the tongue 15 and the edge of the thicker remainder of the closure plate 9.

The tongue 15 projects beyond the flanking fingers 16 and the projection portion is in the form of a hooking latch 18 whose shape can be seen best in Figure 5 of the drawings, it being remembered that Figure 5 shows the complete closure plate in an inverted position. The hooking latch 18 extends throughout the transverse width of the tongue 15 and is intended to co-operate with an abutment that will be referred to below. A flat stop 19 projects downwardly from the bottom of the tongue 15 at a location mid-way between its opposite edges and substantially mid-way between the buttresses 17 and the hooking latch 18.Two small projections 20 that have substantiallythe same thickness as does the tongue 15 are formed in spaced apart relationship with one another at the edge of the major portion of the closure plate 9 which is remote from said tongue 15, the two projections 20 being alongside the upper or top surface of said closure plate 9. Two ramps 21 are formed on the lower surface of the major portion of the clamping plate 9 at positions which are such that, when the clamping plate 9 is installed in the recess 10, they will be located inwardly of that recess 10 just beyond the respective projections 13 (Figure 2).

As mentioned above, the clamping plate 9 is initially separate from the slidable door 6 but is permanently engaged in the recess 10 by sliding it, projections 20 first, into grooves 22 that extend lengthwise of the opposite parallel edges of the recess 10 in the thickness of the slidable door 6, the projections 13 being located immediately below the respective grooves 22. The width of each groove 22 substantially matches the thickness of the major portion of the closure plate 9 and of its fingers 16 and inward sliding of the complete plate 9 can continue until the ramps 21 need to be forced past the projections 13 which is possible because those projections 13 can deflect resilentlyto a sufficient extend to allow this.As soon as the ramps 21 have passed the projections 13, those projections 13 snap back upwardly and come to rest behind the maximum depth sides of the ramps 21 which will prevent the complete closure plate 9 from being removed from the recess 10 unless the projections 13 are deliberately deflected to allow this or destructive force is employed. The small projections 20 bear against the free ends of the two lattice ribs 14 at this time and the fingers 16 are engaged in the portions of the grooves 22 that commence alongside the projections 13 and extend towards the mouth of the recess 10. It is noted that, under these circumstances, the hooking latch 18 is disposed very close to the mouth of the recess 10 with its outermost extremity a short distance inwards from the edge of the slidable door 6 concerned. The hooking latch 18 does not project outwardly from the recess 10.

When the slidable door 6 carrying the complete closure plate 9 as described above is moved generally to the left as seen in Figure 1 of the drawings and to the right as seen in Figures 2 and 3 thereof, the access opening 5 will be progressively closed until an inclined surface 23 on the hooking latch 18 meets an abutment rib 24 at the edge of the access opening 5 towards which the door 6 has been moving. The rib 24 has the same width, parallel to said edge, as does the hooking latch 18 and the striking of said rib 24 by the surface 23 resiliently deflects the latch 18 because of the resilient formation of the tongue 15, and allows the hook of the latch 18 to become engaged around the rib 24.There are surfaces of engagement which are perpendicular to the general plane of the closure plate 9 and of the slidable door 6, one of these surfaces being visible in Figure 5 of the drawings, and it is therefore not possible to release the door 6 without moving the hooking latch 18 downwardly.

The top surface of the tongue 15 is readily accessible in that portion of the recess 10 that is not closed by the top surface 11 of said recess 10 and it is only necessary to press manually downwards thereon, approximately in register with the stop 19, resiliently to deflect the tongue 15 and move the hooking latch 18 downwardly to bring its hook free of engagement with the abutment rib 24. A sliding movement of the door 6 generally to the right as seen in Figures 1,4 and 5 of the drawings and to the left as seen in Figures 2 and 3 at the same time completely disengages the latch whereafterthe manual pressure can be discontinued and the door 6 be slid further to uncover the access opening 5 without difficulty.The downwardly projecting stop 19 strikes the inner wall of a recess 25 in that edge of the access opening 5 which is opposite to the edge carrying the abutment rib 24 and prevents the slidable door 6 from becoming completely disengaged from the tracks 7 in the top panel 3.

Although users will quickly become aquainted with the simple way of latching and unlatching the slidable door 6, it is desirable that the readily manually accessable region of the top surface of the tongue 15 should be marked "press here" or merely "press" or the like to indicate to a new user how to release the closure of the slidable door 6. This may be accomplished by moulding the words into the tongue 15 or by attaching a waterproof label of contrasting colour with a very strong and waterproof adhesive.

The top panel 3 of the poultry crate has an overall thickness, including the thickness of its slidable door 6, of the order of about 30 mms and an important feature of the invention resides in the fact that the closure plate 9 is contained wholly within this overall thickness and does not project therefrom even when the tongue 15 thereof is resiliently deflected to a limited extent to release the hooking latch 18 from the abutment rib 24. Thus, should a heavy article be placed on top of the crate, that article will not depress the tongue 15.

It is self-evident that no simple closure device can ever provide complete protection against accidental unlatching under all conceivable circumstances but the construction and arrangement that has been described, and that is illustrated in the accompanying drawings, enables the slidable door of a container to be latched and unlatched in a particularly quick and easy manner whilst providing a very high degree of security against the closure being accidently released. It is not, of course, essential that a container closure in accordance with the invention should form part of a poultry crate. It could, in fact, be employed with a slidable door of substantially any container and be provided in both smaller and larger sizes than are appropriate for use with poultry crates. When employed in a poultry crate, it is not essential that said crate should be of a wholly or even partly synthetic plastics construction. The crate could be of a more conventional construction and, if preferred, a closure plate equivalent to the closure plate 9 could be made of at least two interconnected metallic parts, one of which would be a spring steel blade equivalent to the tongue 15 and carrying, at its free edge, a hooking latch of metallic construction equivalent to the synthetic plastics latch 18 that has been described.

Claims (12)

1. A releaseable closure for the door of a container which co-operates slidably with an opening in a wall panel of that container, said closure comprising a resiliently deflectable tongue carried by said door and shaped latchingly to engage an abutment at one edge of said opening, the tongue being releasable from such latching engagement by manually depressing a readily accessible portion thereof and said tongue being constructed and arranged so as always to be located wholly within the overall thickness of the wall panel formed with said opening.

2. A releasable closure according to claim 1, wherein a normally free end of said tongue is shaped to define a latch arranged to engage said abutment.

3. A container closure according to claim 2, wherein said latch is in the form of a hook which exhibits a surface that is inclined to the plane of sliding of said door, the surface being so positioned that, upon meeting said abutment when the door is slid towards a closing position, further movement in that direction will cause the tongue to be resiliently deflected until said surface has passed the abutment and the resiliency of the tongue moves it to a position in which the hook is retainingly engaged with that abutment.

4. A releaseable closure according to any preceding claim, wherein said closure and its tongue are formed integrally from a synthetic plastics material.

5. A releaseable closure according to claim 3, wherein that closure and its tongue are fitted in a recess formed along one edge of said slidable door, said closure and said recess being provided with cooperating means which will ensure that, after installation of the closure in the recess, the closure cannot readily be released from that recess.

6. A releaseable closure according to claim 5, wherein the tongue of the closure is provided with a stop arranged normally to prevent the door from being slid in an opening direction beyond a position in which the opening in the wall panel with which it co-operates is substantially fully open.

7. A releaseable closure according to claim 4 or 5, wherein said tongue is flanked at its opposite longitudinal edges by corresponing fingers which are spaced from the respective edges, said fingers having only marginal resiliency and being normally lodged slidably in corresponding elongate grooves formed in opposite marginal walls of the recess in which the closure and its tongue are lodged.

8. A releaseable closure according to any preceding claim, wherein that closure forms part of the openable door of a fowl/poultry crate.

9. A releaseabie closure according to claim 8, wherein the wall panel of said crate in which the releaseable door and its closure are installed has a thickness of substantially 30 mm.

10. A releaseable closure according to claim 8 or 9, wherein the releaseable door in which said closure is installed, the panel in which that door is slidably mounted, and the remaining walls of said crate are all of lattice work construction each providing a plurality of openings whose maximum widths do not exceed substantially 60 mm.

11. A releaseable closure for the door of a container substantially as hereinbefore described with reference to the accompanying drawings.

12. A fowl/poultry crate comprising a door which co-operates slidably with an opening in a wall panel of that poultry crate and which door includes a releaseable closure as claimed in any preceding claim.