CONTAINER AND COMBINATION OF CONTAINER AND SPAWN STRUCTURE

Abstract

In an open topped, stackable, molded plastic container (1), which is generally rectangular with a bottom (2) and first and second pairs of parallel upright walls (3, 4, 5, 6) joined to the bottom and at corners via corner structures (10). Each corner structure comprises a hollow tubular post (13) with a lower protruding stacking pin portion (13p) such that—in a stack—the pin portion of an upper container is received through a hole (14) in a top wall (12) of the corner structure of a lower container onto which said upper container is stacked. Multiple vertical stacking ribs (15a-g) are arranged circumferentially spaced about the hollow tubular post (13). The container is used in combination with a spawn structure in which the mother insects will spawn their eggs. The spawn structure comprises a foldable member and a rigid member.

Claims

1. An open topped, stackable, molded plastic container, which is generally rectangular with a bottom and first and second pairs of parallel upright walls joined to the bottom and at corners via corner structures, each corner structure comprising: a substantially diagonal and upright wall section which, seen in top view, extends diagonally between adjoining upright walls and blends into said upright walls to define the contour of a containment space of the container; and a top wall extending outward from an upper end of the diagonal and upright wall section; and a hollow tubular post extending vertically downward from said top wall, said hollow tubular post being spaced from said diagonal and upright wall section, wherein the top wall has a hole aligned with the hollow tubular post; wherein multiple vertical stacking ribs are arranged circumferentially spaced about the hollow tubular post, each stacking rib having a vertical inner end joined to said hollow tubular post, wherein at least one stacking ribs has a vertical outer end joined to said diagonal and upright wall section and/or to said adjoining upright wall section; and wherein each of said stacking ribs has a lower end, said lower ends being located in a common plane; wherein said tubular post has a protruding stacking pin portion extending downward beyond said common plane of the stacking rib lower ends; such that—in a stack—the pin portion of an upper container is received through the hole in the top wall of the corner structure of a lower container onto which said upper container is stacked.

2. The container according to claim 1, wherein said stacking pin portion does not protrude downward beyond the bottom of the container and the lower ends of the stacking ribs lie above the bottom so that—in a stack—the upper container nests in the lower container.

3. The container according to claim 1, wherein each stacking rib has an upper end joining said top wall.

4. The container according to claim 1, wherein the corner structure further comprises a quarter-circular skirt wall, extending downwards from an outward perimeter of the top wall.

5. The container according to claim 1, wherein a top flange extends outward from an upper end of each upright wall.

6. The container according to claim 5, wherein flange skirt walls depend downwards from the top flanges, parallel to and at a distance from the respective upright walls.

7. The container according to claim 1, adapted for use in an insect breeding facility for breeding insects of the type with crawling mother beetles having a protractable egg-laying tube; adapted to be used in combination with at least one spawn structure in which the mother insects will spawn their eggs, wherein the bottom of the container is provided with spawn structure clamps to receive the spawn structure and allow the spawn structure to be connected to the container.

8. Use of a container according to claim 1 in an insect breeding facility.

9. A stack comprising at least 15 containers according to claim 1.

10. A climate housing of an insect breeding facility, comprising multiple stacks according to claim 9.

11. In combination: an insect spawning container adapted for use in an insect breeding facility for breeding insects of the type with crawling mother beetles having a protractable egg-laying tube; wherein the insect spawning container comprises a bottom and first and second pairs of parallel upright walls; at least one spawn structure in which the mother insects will spawn their eggs, comprising a foldable member with a fold section provided centrally between, and via hinges connected to, a perforated left-hand section and a perforated right-hand section; the spawn structure further comprising a rigid plate; wherein the foldable member and the rigid plate are movable with respect to each other between an open configuration and a closed spawning configuration; wherein in the closed spawning configuration the foldable member is folded such that the left-hand section and the right-hand section are parallel to each other, with the rigid plate sandwiched between the sections, creating a multitude of crevices between the rigid plate and inner faces of the folded member, the crevices having dimensions tuned to the egg-laying tube of the mother beetles; and in which spawning configuration outer faces of the folded member form two climbing faces; wherein the spawn structure in the closed spawning configuration is positioned in the container such that the mother beetles are able to crawl from the bottom onto and up along the climbing faces of the spawn structure into the crevices; and wherein in the open configuration the foldable member is folded open allowing harvesting of the eggs.

12. The combination according to claim 11, wherein the foldable member has a length in the direction of the fold section, corresponding to the length of the rigid plate, and wherein the width of the left-hand and right-hand sections corresponds to the width of the rigid plate.

13. The combination according to claim 11, wherein the fold section comprises an elongated slit seat having a length corresponding to the length of the rigid plate, a width corresponding to the thickness of the rigid plate, and a depth to accommodate the rigid plate.

14. The combination according to claim 11, wherein at least one of the hinges between the left-hand and right-hand sections and the fold section is pre-stressed opposite the folding direction.

15. The combination according to claim 11, wherein the ends of the inner faces of the foldable member opposite the fold section and/or the sides of the foldable member adjacent the fold section taper towards the outer faces.

16. The combination according to claim 11, wherein the bottom of the insect spawning container is provided with spawn structure clamps to receive the spawn structure in the spawning configuration and allow the spawn structure to be connected to the container.

17. The combination according to claim 11, wherein the length of the spawn structure is between 70-100%, of that of the insect spawning container, and wherein spawn structure are provided in the longitudinal direction of the spawning container.

18. The combination according to claim 11, wherein the container is according to any of the preceding claims 1-7.

19. Use of a combination according to claim 11.

20. A method for breeding insects of the type with crawling mother beetles having a protractable egg-laying tube, comprising the steps of: providing a plurality of spawning containers in combination with spawn structures in the closed spawning configuration, according to claim 1; providing adult insects including mother insects to the spawning containers; and periodically repeating the steps of: removing a spawn structure from the spawning container, leaving the adult insects in the spawning container; folding open the foldable member of the spawn structure; removing the foldable member and/or the rigid plate of the spawn structure holding the eggs, and allowing the eggs to hatch; providing an empty spawn structure in the closed spawning configuration in each spawning container.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The invention is further elucidated in relation to the drawings, in which:

[0066] FIG. 1a represents a side view of a stack of two containers according to the first aspect of the present invention;

[0067] FIG. 1b represents a perspective top view of a container according to the first and second aspect of the invention;

[0068] FIG. 2a represents a perspective bottom view of a corner structure of the container of FIGS. 1a and 1b;

[0069] FIG. 2b represents a detailed side view of a corner structure of the container of FIGS. 1a and 1 b;

[0070] FIG. 2c represents a cross-section of the corner structures of two stacked containers of FIG. 1a;

[0071] FIG. 2d represents a bottom view of the corners structure of the container of FIGS. 1a and 1 b;

[0072] FIG. 3a-3e represent a foldable member of a spawn structure of a combination according to a second aspect of the invention, respectively in a perspective view from below, a top view, a side view, a perspective view from above and a detail thereof;

[0073] FIG. 4 represents a perspective view onto a spawn structure according to a second aspect of the invention in the open configuration;

[0074] FIGS. 5a and 5b represent perspective views onto the entire spawn structure according to a second aspect of the invention in the closed configuration and a detail thereof;

[0075] FIGS. 6a-6d represent details of the fold section of the foldable member of the spawn structure according to a second aspect of the invention;

[0076] FIGS. 7a, 7b and 8a-8d represent detailed perspective views of a spawn structure clamp and a complementary container connector on the foldable plate;

[0077] FIGS. 9a and 9b represent a perspective view and a top view of a combination of an inspect spawning container and a spawn structure according to the second aspect of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

[0078] In FIGS. 1a-2d, an open topped, stackable, plastic container 1 of the first aspect of the invention is shown, with details of an inventive corner structure 10. In FIGS. 1a and 2c, two stacked containers 1 and 1′ are shown, wherein same parts are given same reference numerals to which an apostrophe (′) has been added.

[0079] The container is preferably a monolithically injection molded container, preferably made from PP. The container 1 is generally rectangular with a bottom 2 and first and second pairs of parallel upright walls 2, 3, 4, 5 joined to the bottom 2 and at corners via inventive corner structures 10, which will be discussed in detail below.

[0080] Here, at a bottom end, the upright walls 2, 3; 4, 5 join (and blend into) the bottom via curved sections 2c, 3c; 4c, 5c. A common wall thickness for this type of containers is 2-3.5 mm.

[0081] The dimensions of such a container are e.g. a length of 700-800 mm, a width of 500-600 mm and a height of 100-200 mm. With outer dimensions of length 79×59×19 cm, an containment space 8 of the container of over 2700 cm.sup.2 is obtained.

[0082] Such a container is suitable for use in insect breeding/rearing, e.g. to house egg-laying mother insects, possibly in combination with a spawn structure such as according to the second aspect of the invention. In addition, the containers can be used for hatching eggs, rearing baby-larvae and the process of rearing larvae into adult insects.

[0083] It is conceivable that the container is provided with spawn structure clamps 20, to be used in combination according to the second aspect of the invention. This will be further elucidated below. The container may also be suitable for accommodating a hatch structure, e.g. a hatch structure in which parts of the spawn structure of the second aspect onto which the eggs are laid are accommodated. Possibly, the bottom of the container is at least partly removed to allow eggs or larvae to drop from the spawn structure into another container.

[0084] In embodiments, e.g. when the container is used for housing mother insects, it is possible to remove at least a part of the bottom of the container, and replace it by a mesh, e.g. for the removal of excrements.

[0085] In FIG. 1a, a stack 9 of two containers according to the invention is shown. Advantageously, a stack comprises at least twenty containers. Preferably, a few stacks are positioned on a pallet, e.g. 2-4 stacks. Advantageously, an insect breeding facility is provided with one or more climate housings, or climate areas, in which multiple stacks of containers are provided.

[0086] The corner structure 10 according to the first aspect of the invention will be explained in relation to the corner structure 10 in FIG. 1b between walls 4 and 5. In the shown embodiment, all four corner structures 10 have the same configuration.

[0087] The corner structure 10 comprises a substantially diagonal and upright wall section 11 which, seen in top view, extends diagonally between adjoining upright walls 4,5 and blends into said upright walls to define the contour of a containment space 8 of the container. In particular, in the shown embodiment, as visible in FIG. 1b and FIGS. 2a, 2b, and 2d, the upright wall section 11 comprises three portions: portion 11a adjacent wall 5, upright wall portion 11c adjacent wall 4, and upright wall portion 11b therebetween.

[0088] Ata bottom end, the upright wall section 11 is joined to the bottom similar to the type of join of the upright walls to the bottom, via curved sections 11a1, 11b1, 11c1.

[0089] In the shown embodiment, a top wall 12 extends outward from an upper end of the diagonal and upright wall section, to extend essentially parallel to the bottom 2.

[0090] In the shown embodiment, the first and second pairs of parallel upright walls 2,3; 4,5 comprise a top flange 2a, 3a; 4a, 5a extending outward from an upper end of the upright walls. Here, the top flanges and the top walls 12 all extend horizontally, parallel to the bottom 2 of the container. Here, both the top flanges and the top walls 12 are provided with drainage holes 17, as visible in FIG. 1b and in FIG. 2d.

[0091] In the shown embodiment, the top flanges 2a, 3a; 4a, 5a are further provided with flange skirt walls 2b, 3b; 4b, 5b, depending downwards from the top flanges, essentially parallel to and at a distance from the first and second pairs of parallel upright walls, and wherein preferably at least one of the skirt walls is provided with a label 18, e.g. via in-mould labelling.

[0092] Here, also the corner structure 10 comprises a quarter-circular skirt wall 12c, depending downwards from an outward perimeter of the top wall 12 and at a distance from the diagonal and upright wall section.

[0093] According to the first aspect of the invention, a hollow tubular post 13 extends vertically downward from said top wall 12, said hollow tubular post 13 being spaced from said diagonal and upright wall section. Here the tubular post 13 is also spaced from the quarter-circular skirt wall 12c. The top wall has a hole 14 aligned with the hollow tubular post 13.

[0094] Multiple, e.g. at least three, and in the shown embodiment 7 vertical stacking ribs 15a-15g are arranged circumferentially spaced about the hollow tubular post 13, each stacking rib having a vertical inner end joined to said hollow tubular post. The stacking ribs have an exemplary thickness of 2-4 mm.

[0095] At least one, here two of said stacking ribs 15a, 15g have vertical outer end joined to said diagonal and upright wall section 11a, 11c respectively. It is also conceivable that the vertical outer ends are joined to a wall of the first and second pairs of parallel upright walls.

[0096] Furthermore, here part of vertical outer ends of stacking ribs 15c, 15d, 15e is joined to said quarter-circular skirt wall 12c. The vertical outer end of stacking ribs 15b, 15f is not joined to any other part.

[0097] Each of the stacking ribs has an upper end. Here, the upper ends of said stacking ribs 15a-15g join said top wall 12. Furthermore, each of the stacking ribs has a lower end. According to the first aspect of the invention, said lower ends are located in a common plane C. Here, the lower ends are slightly rounded, which is advantageous, as visible in FIG. 2c, to match the hole 14 in which the protruding stacking pin portion is received when stacked.

[0098] The tubular post 13 has a protruding stacking pin portion 13p extending downward beyond said common plane of the stacking rib lower ends. In the shown embodiment, the protruding stacking pin portion 13p comprises a tapering end portion 13p′. Here, the bottom end of the stacking pin portion 13p is provided with a drainage hole 13h. As visible in particular in FIG. 2c, in a stack the pin portion 13p′ of an upper container 1′ is received through the hole 14 in the top wall 12 of the corner structure of a lower container 1 onto which said upper container is stacked.

[0099] In the shown preferred embodiment, said stacking pin portion 13p does not protrude downward beyond the bottom 2 of the container and the lower ends of the stacking ribs in common plane C lie above the bottom so that in a stack the upper container nests in the lower container. In particular, the lower ends of the stacking ribs of the upper container, here ribs 15d′ and 15a′ are visible, rest onto the top wall 12 of the lower container, while the stacking pin portion 13p′ is stacked through the hole 14 into the tubular post 13 of the lower container 1. Here, in a stack, the bottom 2′ of the upper container is slightly below the level of the top walls of the corner structures of the lower container. Hence, there is an overlap between the containers 1 and 1′. In other words, the relative distance between the containers is negative.

[0100] The length of the stacking pin portion attributes to the stability of a stack of containers. An advantageous length is 30 mm, for containers having a height of 190 mm, resulting in a stacking height of a container of about 160 mm.

[0101] In embodiments (not shown) with the stacking pin portion 13p protruding downward beyond the bottom 2 of the container, the lowermost container of a stack will rest on the stacking pin portions and not on its bottom. Furthermore, the relative distance between containers may be enlarged. The relative distance between containers is determined by the location of the common plane C of the lower ends of the stacking ribs.

[0102] In embodiments (not shown) with the bottom end of the stacking pin portion 13p at a distance above the bottom 2 of the container, the lowermost container of a stack will rest on the bottom and not on the stacking pin portions. Furthermore, the relative distance between containers may be very small, such that the containers overlap to a larger extent.

[0103] The second aspect of the invention relates to the combination of an insect spawning container 1 and at least one spawn structure 50, an example of which is shown in FIGS. 9a and 9b. The insect spawning container 1 here corresponds to the container 1 of the first aspect of the invention. Alternative container configurations are also conceivable, in particular stackable containers, as long as they are suitable to be used as an insect spawning container in an insect breeding facility for breeding insects of the type with crawling mother beetles having a protractable egg-laying tube, such as lesser mealworms or zophobas morios. The insect spawning container 1 comprises a bottom 2, first and second pairs 2,3; 4,5 of parallel upright walls and a containment space 8 for the mother beetles.

[0104] A spawn structure 50, here 4 spawn structures 50, is provided in combination with the container 1, for the mother insects to spawn their eggs. Here, the spawn structures 50 are provided in the longitudinal direction of the spawning container 1, at side parts of the container, leaving the central area between the spawn structures 50 open. In the shown configuration, the length of the spawn structure is between 70-100%, in particular 80-90%, of that of the insect spawning container. The width of a spawn structure is relatively small, in the order of 1-5% of the width of the container, in particular in the order of 8-20 mm, in particular 10-15 mm.

[0105] In the shown embodiment, as visible in FIG. 1b, FIGS. 9a and 9b, the bottom 2 of the container is possibly provided with spawn structure clamps 20, to receive a spawn structure in the spawning configuration and allow the spawn structure to be connected to the container 2. Preferably, this is a spawn structure according to the second aspect of the invention.

[0106] The spawn structure comprises a foldable member 51 with perforations or cut-aways 51c, as shown in FIGS. 3a-3e, and a rigid plate 52, visible in FIG. 4. The foldable member 51 and the rigid plate 52 are preferably monolithically injection molded plastic products.

[0107] In FIGS. 3a-3e the foldable member 51 of the spawn structure according to the second aspect of the invention is shown in detail, without the rigid plate 52 of the spawn structure 50.

[0108] According to the second aspect of the invention, this foldable member 51 comprises a fold section 51f provided centrally between, and via hinges 51g, 51h connected to, a perforated left-hand section 51a and a perforated right-hand section 51b. The left-hand section 51a and right-hand section 51b are embodied as plates, and are provided with perforations 51c. In the shown configuration, the foldable member 51 comprises 8 segments, here each provided with 80-81 perforations. Each section 51a, 51b comprises an outer face 51ao, 51bo and an inner face 51ai, 51bi, respectively.

[0109] According to the second aspect of the invention, the foldable member and the rigid plate are movable with respect to each other between an open configuration and a closed spawning configuration. The mutual distance between the foldable member and rigid plate is increased and decreased during this movement, in particular the distance between the inner faces 51ai, 51bi.

[0110] In FIGS. 5a, 5b and 9a, 9b the spawn structure 50 is shown in a closed spawning configuration. In the spawning configuration, the foldable member 51 is folded such that the left-hand section 51a and the right-hand section 51b are parallel to each other. The rigid plate 52 is sandwitched between the sections 51a, 51b. A multitude of crevices 53 is created between the rigid plate 52 and inner faces 51ai, 51bi of the folded member. These crevices 53 have dimensions tuned to the egg-laying tube of the mother beetles. For breeding lesser mealworms the width of the crevices is 0.2-1.2 mm, while for breeding zophobas morios the width of the crevices is 0.2-1.8 mm. The depth of the crevices may vary between 0.5-10.0 mm.

[0111] In the spawning configuration, as visible in FIGS. 9a and 9b, the spawn structures 50 are positioned in the container, here adjacent the bottom 2. The outer faces 51ao, 51bo of the folded member 51 form two climbing faces which are positioned adjacent the bottom of the container. An advantage of the foldable member is that crevices are created at both sides of the spawn structure.

[0112] The spawn structure in the closed spawning configuration is positioned in the container such that the mother beetles are able to crawl from the bottom onto and up along the climbing faces of the spawn structure into the crevices, e.g. via the spawn structure clamps 20.

[0113] In an open configuration, as visible in FIG. 4, the foldable member 51 is folded open, and the distance between the foldable member 51 and rigid plate 52 is increased, allowing harvesting of the eggs, and/or cleaning of the spawn structure.

[0114] The configuration of the spawn structure according to the second aspect of the invention allows efficient handling of the spawn structure, e.g. to switch between the closed and the open configuration. An increase in efficiency will may attribute to an increased yield, in particular during scaling up the breeding of insects.

[0115] Furthermore, an increased yield is obtained by allowing the opening of the spawn structure by a sideways movement of the foldable member 51, in particular of the left-hand part 51a and the right-hand part 51b, similar to the opening of a book. This side-ways opening diminishes the risk of damaging the eggs, as no transversal relative sliding movement of the foldable member and rigid plate of the spawn structure is possible.

[0116] Also attributing to the prevention of relative sliding is providing the fold section 51f with an elongated slit seat 51fs having a length corresponding to the length of the rigid plate, a width essentially corresponding to the thickness of the rigid plate, and a depth to accommodate the rigid plate.

[0117] This is shown in more detail in FIGS. 6a-6d. In particular, in FIG. 6a the ‘empty’ slit 51fs without the rigid plate 52 is shown. Also, an optionally provided rib 51r in the slit 51fs is visible, which may be provided to attribute to fixation of the rigid plate 52.

[0118] In FIG. 6d, the rigid plate 52 is positioned into the slit seat 51fs.

[0119] The yield correlates with the number of crevices 53 having the correct dimensions.

[0120] In particular in FIG. 5b, a detail of an advantageous type perforation is visible. The perforations 51c are circular, and here provided with a bevelled part 51cb, such that the perforation 51c comprises a relatively large diameter adjacent the outer surface 51ao of the foldable plate, tapering to a smaller diameter adjacent a cylindrical part 51cc of the perforation, which ends at the inner surface 51ai of the foldable plate 51. The crevices 53 are formed between the end of the cylindrical part 51cc and the rigid plate 52.

[0121] Advantageously, in the configuration as shown as can be derived in particular from FIG. 4, the foldable member 51 has a length in the direction of the fold section 51f, essentially corresponding to the length of the rigid plate 52, and wherein the width of the left-hand and right-hand sections essentially correspond to the width of the rigid plate. As a result, no additional crevices or clear spaces are created between the foldable member and rigid plate, other than the envisaged crevices.

[0122] To obtain crevices having dimensions tuned to the egg-laying tube of the mother beetles, advantageously the inner faces 51ai, 51bi of the foldable member are provided with protrusions 51p, in particular visible in FIG. 3e. E.g. protrusions of 0.3-0.4 mm high are suitable to create crevices of the desired dimensions.

[0123] In view of the importance of the dimensions of the crevices, it is important to accurately control the mutual distance between the foldable member and the rigid plate in the closed spawning configuration. The provision of protrusions 51p ensures a minimum distance between the parts of the spawn structure. On the other hand, measures may be contemplated to reduce the risk of having a too large mutual distance.

[0124] E.g. in FIG. 3a, elongated savings 51s are visible between the perforated sections. These are provided to prevent bulging out of the left- and right-hand sections.

[0125] Another measure to control the dimensions of the crevices is to provide a pre-stress to at least one of the hinges 51g, 51h between the left-hand and right-hand sections 51a, 51b and the fold section 51f, opposite the folding direction.

[0126] In FIG. 3c, the pre-stress is visible as a slight angle α of 1-1.5° between the right-hand section 51b and the horizontal, while here the left-hand section 51 does not include an angle with the horizontal.

[0127] In FIG. 6a, it is visible that sides 51ae, 51be of the left-hand section 51a and right-hand section 51b respectively of the foldable member 51, adjacent the fold section 51f, taper towards the outer faces 51ao, 51bo respectively. By allowing the ends to taper towards the outer faces, in the spawning configuration an opening is created, between the parallel left-hand section and the right-hand section on the one hand, and the rigid plate on the other hand. This opening facilitates the increasing of the distance between the foldable member and rigid plate of the spawn structure to the open configuration. Possibly, the opening allow the use of an opening tool to increase the mutual distance.

[0128] wherein the ends of the inner faces of the foldable member opposite the fold section and/or the sides of the foldable member adjacent the fold section taper towards the outer faces.

[0129] Yet another optional measure to control the dimensions of the crevices is to ensure a proper closing of the spawn structure in the closed spawning configuration. For example, a clip is provided to close the sandwich of left-hand section 51a, rigid plate 52 and right-hand section 51b opposite the fold section 51f.

[0130] In the shown embodiments, the spawn structure is positioned in the crate via spawn structure clamps 20 provided at the bottom of the insect spawning container 1. The design of these clamps 20 attributes to a proper closing of the sandwiched spawn structure 50.

[0131] In FIGS. 7a-8d, the spawn structure clamp 20 is shown in further detail. The bottom 2 of the insect spawning container 1 is provided with spawn structure clamps 20 to receive the spawn structure 50 in the spawning configuration, and allow the spawn structure to be connected to the container.

[0132] In the shown embodiment, the spawn structure clamp 20 comprises opposed protruding fingers 20a, 20b, protruding from the bottom 2 of the insect spawning container, between which a spawn structure receiving groove 20c is provided. The configuration of the opposed fingers is such that the bottom of the groove between the fingers is provided at a distance from the bottom of the spawning container, e.g. 2-4, preferably 3 mm.

[0133] The fingers have tapering ends, to provide a guide surface 20g for the spawn structure. This is I particular visible in FIGS. 8a and 8b, in which the entrance of the spawn structure 50, and the closing to the closed spawning configuration is elucidated.

[0134] To define the position of the spawn structure 50 with respect to the container 1, advantageously the ends of the outer faces 50ao, 50bo of the foldable member opposite the fold section are provided with complementary container connectors 50ac, 50bc. The complementary container connectors 50ac, 50bc allow the spawn structure 50 to be connected to the container 1 in the spawning configuration. Here, the configuration of the spawn structure clamps 20 and the complementary container connectors 50ac, 50bc is such that by connecting the spawn structure to the container, the position of the spawn structure in the container is defined. Possible container connectors are snap-fitments, protruding from the outer faces.