Tray container

Abstract

The invention relates to a tray container (10) for storing and transporting liquid or flowable fillers, comprising a thin-walled rigid plastic inner container (12) made of thermoplastic, comprising horizontal and vertical tubular rods (18, 18 ') welded to each other, the invention relates to a tubular grille frame (14) which is made of a plastic inner container (12) and which tightly encloses the plastic inner container (12) as a supporting jacket, comprising a bottom tray (16) on which the plastic inner container (12) is placed and to which the tubular grille frame (14) is rigidly connected, at least two rod-shaped transverse pieces (22) being arranged above the plastic inner container (12), the two ends of the tube-shaped grid frame (14) are fixed on two opposite side walls in the upper area of the tube-shaped grid frame (14). In order to protect the upper region of the tubular grid frame (14) against the adverse effects of impact loads and transport vibrations, it is provided that the transverse pieces (22) are designed as elastic spring elements (24).

Description

Technical Field

[0001] The invention relates to a pallet container for storing and transporting liquid or flowable filling materials, comprising a thin-walled rigid plastic inner container made of thermoplastic plastic, a tubular grid frame consisting of horizontal and vertical tubular rods welded to one another as a supporting sheath tightly surrounding the plastic inner container, and a bottom pallet on which the plastic inner container is placed and to which the tubular grid frame is firmly connected, wherein two rod-shaped cross members are arranged above the plastic inner container and are fixed with their two ends to two opposite side walls in the upper region of the tubular grid frame. Background Art

[0002] The rod-shaped cross piece should prevent excessive bulging of the plastic inner container or its upper top with the central screw cap, especially in the case of transport vibrations and dynamic oscillations, and is also used to keep the plastic inner container in the tubular grid frame on the bottom pallet and prevent it from sliding out of the tubular grid frame in the case of an accidental tipping over of the pallet container. In order to make it possible to easily replace the plastic inner container for multiple uses of the pallet container, the cross piece is releasably fixed (generally screwed) at its two ends in the upper area of ​​the tubular grid frame. For example, such a pallet container with two parallel extending cross pieces is known from the publication WO2012085940 A2. In the case of the pallet container described in the publication DE 4425 630 A1, four cross pieces are provided, wherein two obliquely crossed cross pieces cover half of the plastic inner container respectively.

[0003] question: When pallet containers are to be used for the storage and transportation of dangerous liquid fillings (e.g. aggressive chemicals), these pallet containers require a so-called hazardous goods permit from a national official inspection agency, which in Germany is the BAM (Federal Agency for Material Inspection). In order to obtain such a hazardous goods permit, different types of pallet containers are subjected to special structural type tests with different load states, such as internal pressure tests, drop tests and vibration tests. In the case of the vibration test, strong transport loads (shocks, vibrations) towards the filled pallet container are simulated. Here, the liquid column in the plastic inner container may enter into strong dynamic oscillations. These oscillations cause strong alternating loads towards the side walls of the plastic inner container and are directly transmitted to the tubular grid frame that tightly surrounds the plastic inner container as a supporting sheath. Because pallet containers usually have two longer and two shorter side walls, the two longer opposite side walls are loaded to a greater extent and are therefore stabilized by the cross-pieces that are bridged (übergreifenden, or spanned). Similarly, the upper top of the plastic inner container implements strong dynamic up and down oscillations, which act on the cross-pieces. In the case of an upward bulging of the upper roof, the known straight crosspieces extending parallel to one another are pressed upward and strong tensile stresses act on the two fixing points of the crosspiece on the tubular grid frame between the opposite side walls of the tubular grid frame, whereby the upper region of the tubular grid frame is pulled inwards. In the case of a lowering of the upper roof, the plastic inner container and the opposite side walls of the tubular grid frame bulge outwards, wherein the upper region of the tubular grid frame is also pressed outwards. Here, the crosspiece is again loaded with a greater tensile load at its two fixing points. This alternating load is repeated at a higher frequency over a longer period of time and exerts a wear effect on the corresponding components of the pallet container. Summary of the invention

[0004] Purpose: The object of the invention is to reduce these disadvantageous tensile stresses and to intercept the effect of the tensile stresses on the fastening points of the cross-pieces and, respectively, on the upper region of the tubular lattice framework and to reduce the stress peaks.

[0005] Solution: The deliberate reduction of the unfavorable tensile stresses is achieved by configuring the two rod-shaped crosspieces as elastic spring elements. The elastic configuration of the two crosspieces as spring elements disengages the rigid connection of the conventional linearly extending crosspieces to the opposite side walls of the tubular lattice frame and is "built-in" with limited elasticity in the upper plane of the tubular lattice frame. In the case of an upward bulging of the upper top, the tensile forces occurring towards the two fixing points of the crosspieces are reduced and the upper region of the tubular lattice frame is pulled inward less. In the case of lateral bulging of the plastic inner container and the associated outward bulging of the opposite side walls of the tubular lattice frame, the tensile forces occurring in the upper region of the tubular lattice frame are significantly reduced by the crosspieces configured as elastic spring elements and the operational safety of the filled pallet container in the case of dynamic transport loads is significantly increased.

[0006] According to the invention, it is provided that the cross-piece designed as an elastic spring element is not formed to extend nonlinearly (i.e. straightly), but rather has one or more arched sections. In this case, the actual length of the cross-piece between its two fixing points is designed to be greater than the direct distance between the two fixing points at the ends of the cross-piece in the upper region of the tubular lattice frame. Due to this structural design, the cross-piece is on the one hand flexible in its horizontal longitudinal direction in the case of tensile loads (when the tubular lattice frame bulges outwards), and on the other hand it is designed to be flexible in the vertical direction in the case of lateral compressive loads (due to the upward bulging of the upper roof of the plastic inner container).

[0007] This is achieved in one embodiment of the invention in that the crosspiece is not designed to extend linearly but rather in an arc-shaped manner between its two fastening points and has a relatively large arc.

[0008] In a preferred embodiment, the configuration of the two crosspieces as elastic spring elements is achieved by an arched shape with relatively large formed arches. The crosspieces are arched in a horizontal plane (viewed in the installed state), wherein the arches have a relatively large radius and point outward in the direction of two oppositely disposed shorter side walls of the tubular grid frame. In the installed state, the arched crosspieces thus lie flat on the upper roof of the plastic inner container, wherein the arches of the two crosspieces are oriented pointing away from each other.

[0009] The two crosspieces are expediently guided through a respective retaining device in the form of a closed retaining eyelet which is formed from the upper roof of the plastic inner container. In an alternative form, the retaining device formed from the upper roof of the plastic inner container can also be designed as a bearing journal open on one side. These bearing journals open on one side are also referred to below as hook eyes.

[0010] The closed retaining eye or the bearing journal open on one side is arranged laterally next to the central filling opening of the plastic inner container which can be closed by means of a screw cap, and the middle of the arch of the two cross pieces is just below the retaining eye or below the bearing journal. The cross piece with its arched shape can yield elastically in the vertical direction and adapt to the bulging completely following the shape of the upper head in the event of an upward and downward bulging of the upper head (e.g. also in the event of an internal pressure test or a drop test) with its arched shape.

[0011] In a further embodiment of the invention, the cross piece can be designed as an elastic spring element also with two or three smaller arches with a relatively small radius.

[0012] Compared to the conventional straight cross-pieces, the fastening point of the curved, arched cross-piece is moved further toward the center of the upper region of the tubular lattice frame, where the greatest bulges are to occur with the greatest tensile loads and be caught.

[0013] In the case of a vibration test, the arched cross-piece acts like an elastic spring. During the vibration, the upper top of the inner container oscillates upward and downward. These oscillations cause elastic bending of the previously common straight cross-piece upward and downward at its upper and lower end points, which is directly converted into a shortening of the distance between the fixing points. Due to this shortening of the distance, the tubular grid frame is pulled significantly inwards in the upper region during each stroke. With the new "spring solution" that also yields in the longitudinal direction, significantly reduced deformations are obtained at the upper edge of the tubular grid frame and thus reduced loads on the pallet container.

[0014] In order to achieve an optimal elasticity and spring action of the cross-piece, it is provided that the cross-piece is designed to be between 1% and 5% greater in terms of the length of its arch line (bogenline, or arc) between its two fixing points than the direct distance between the two fixing points (according to the chord length). The arched dimensions and the arched shape of the cross-piece are thereby realized as an elastic spring element.

[0015] In a preferred design of the invention, it is provided that the two ends of the cross piece are strongly pressed in the radial direction, a corresponding internal thread (e.g. M8) is formed directly into the pressed part and the two ends of the cross piece are firmly screwed on the upper horizontal or vertical tubular rods of the tubular lattice frame at the end side. For this design variant, it is provided that the two ends of the cross piece are screwed on the upper ends of two adjacent vertical tubular rods at the end side.

[0016] In another embodiment of the invention, it is provided that a nut with an internal thread is firmly inserted into each of the two ends of the cross piece at the end, and the cross piece is accordingly firmly screwed at the end (so to speak in the axial direction) to the upper horizontal or vertical tubular rod of the tubular lattice frame. In this case, the nut firmly and non-detachably inserted into the cross piece designed as a hollow tubular profile (Hohlrohr-Profil, or hollow tubular profile) can be easily pressed in, squeezed or welded. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention is further explained and described below with the aid of the embodiments shown in the accompanying drawings. Figure 1 A pallet container according to the invention is shown in a perspective view, Figure 2 Shows the direction according to Figure 1 An enlarged partial view of the upper region of the pallet container according to the invention, Figure 3 shows a top view towards the transverse member configured as a spring element, Figure 4 A side view toward another embodiment of the cross member is shown, Figure 5 Shows the direction according to Figure 4 An enlarged partial view of the left end region of the cross member, Figure 6 An enlarged partial view showing the connection of the cross-member to the upper region of the tubular lattice frame is shown, Figure 7 The right-hand end region of the cross piece with the inserted nut is shown in an enlarged partial view, Figure 8 An enlarged cross-sectional partial view showing the screw connection of the cross piece at the end face at the upper region of the tubular lattice frame, Fig. 9 The hook eyelets (support journals) of the bridging cross-piece formed from the upper top of the plastic inner container are shown in a partial view, and; Fig.10 An enlarged cross-sectional partial view of a conventional attachment with a cross member to an upper region of a tubular lattice frame is shown. DETAILED DESCRIPTION

[0018] exist Figure 11 shows a pallet container 10 (also referred to as "IBC" = Intermediate Bulk Container) according to the invention for storing and transporting liquid or flowable filling materials. The pallet container 10 comprises a thin-walled rigid plastic inner container 12 made of thermoplastic plastic, a tubular grid frame 14 formed of horizontal and vertical tubular rods 18, 20 welded to one another as a supporting jacket tightly surrounding the plastic inner container 12, and a bottom tray 16 on which the plastic inner container 12 is placed and to which the tubular grid frame 14 is firmly connected. Two bar-shaped cross members 22 are arranged above the plastic inner container 12, which are fixed with their two ends to two opposite side walls of the upper tubular grid frame 14. Here, the two cross members 22 are designed as elastic spring elements 24 in an arched shape. The special structural design of the cross member 22 is characterized in that it is not designed in a straight line or linear manner between its two fixing points 26, 28, but in an arched manner and has a relatively large arch 34. The length of the crosspiece 22 between its two fixing points 26, 28 is designed in a completely unusual manner to be greater than the direct distance between the two fixing points 26, 28 at the ends of the crosspiece 22. In this embodiment, the fixing points 26, 28 at the ends of the crosspiece 22 are arranged at two vertical bars, respectively, directly below the uppermost horizontally surrounding tubular bar 18 between two opposite side walls of the tubular lattice frame 14.

[0019] In the specific case, the length of the cross-piece 22 between its two fixing points 26, 28 is designed to be between 1% and 5%, preferably 3%, greater than the direct distance between the two fixing points 26, 28. For a standard pallet container with the same width and length dimensions and a filling volume of 600, 1000 or 1200 liters, the distance between the two fixing points 26, 28 is about 960 mm and the effective (or actual) length of the cross-piece 22 is about 993 mm. For the same standard pallet container, the cross-piece 22 in an arched configuration should have a larger arch radius of between 300 mm and 700 mm, preferably 500 mm.

[0020] The structural design scheme described above of the present invention is Figure 2 Here it becomes clear that the arched crosspiece 22 in the installed state lies flat on the upper top 38 of the plastic inner container 12 in a horizontal plane, wherein the larger arches 34 of the two crosspieces 22 are oriented away from each other.

[0021] In an alternative embodiment, it can be provided that the crosspiece 22 is designed with two or three elastic spring elements oriented in a horizontal plane and having a relatively small curvature and a relatively small radius.

[0022] In any case, the arched cross-piece 22 is accordingly guided in the installed state through a retaining eyelet 40 formed from the upper top 38 of the plastic inner container 12, wherein the retaining eyelet 40 is arranged across the middle of the installed arched cross-piece 22 (another form of retaining eyelet is in Fig. 9 ).

[0023] Figure 3 A top view of an arched cross-piece 22 designed as a spring element with a large arch radius of about 500 mm is shown. These cross-pieces can be designed as hollow tubes with a circular or square cross section. In a preferred embodiment, the cross-pieces 22, 42 have a circular tubular profile with a diameter between 16 mm and 24 mm, preferably 20 mm, and a wall thickness between 0.8 mm and 1.2 mm, preferably 0.9 mm. According to another embodiment, the cross-pieces 22, 42 can also have a square tubular profile with a side length between 14 mm and 20 mm, preferably 16 mm, and a wall thickness between 0.8 mm and 1.2 mm, preferably 0.9 mm.

[0024] exist Figure 4 4 shows a side view towards another embodiment of a cross member 42 with two arches, which in its end region, when viewed in the installed state, has a correspondingly downwardly formed smaller arch 36 with a relatively small radius and an end pointing upwards, and (as in Figure 8 The ends of the two arched crosspieces 42 with the smaller arch 36 with a smaller radius formed downwards are shown in an enlarged partial view. Figure 5 A nut 30 with an internal thread 44 (eg M8 or M10) is firmly inserted into the open end of the hollow tube profile with two arched cross pieces 42 (see also Figure 7 ). The nut 30 which is inserted in a non-releasable manner can be easily pressed in, squeezed or welded.

[0025] A possible fastening option in which a respective threaded screw 48 is screwed into the end of the hollow tube profile of the crosspiece 22 at the end side is Figure 6 Here, the cross piece 22 is fastened to the flattened ends of the upper parts of the two oppositely disposed vertical tubular rods 20 by means of a threaded screw 48 screwed in horizontally from the outside at the end side.

[0026] Figure 7In a corresponding manner, the open end of the hollow tubular profile is shown with a securely inserted nut 30 with an internal thread 44 (with only one larger arched) crosspiece 22. As described above, the crosspiece 42 with two arches is screwed securely but detachably from below at the end against the uppermost surrounding horizontal tubular rod 18 of the tubular lattice frame.

[0027] Another possible fastening option with a screw connection at the end with two curved transverse elements 42 is shown in an enlarged manner in FIG. Figure 8 . Here, the two ends of the cross-piece 42 with two arches are strongly pressed in the radial direction, wherein the corresponding internal threads 46 are directly formed into the extrusion part 32. Here, the two arched cross-pieces 42 with smaller arches at their end regions are fastened from below at the end side relative to the uppermost horizontal tubular rod 18 by means of a threaded screw 48 screwed in vertically from above. Expediently, the uppermost horizontal tubular rod 18 is slightly sunken at the top at the bore and the threaded screw 48 is embodied as a flat head, countersunk head or pan head screw (Linsenkopfschraube, or slotted screw) so that it does not protrude upwards. The extrusion part 32 with the correspondingly formed internal threads 46 can naturally also be realized in the case of a cross-piece 22 (with only one larger arch). Furthermore, the end-side screw connection has the advantage that the screw tip is completely located in the hollow tube profile of the crosspiece 22 , 42 and is covered, so that it can no longer be damaged as is often the case with currently common open screw connections with protruding screw tips.

[0028] The straight transverse pieces that are common today can only be screwed together poorly with the screw end side directly on the central axis. When the screw is tightened, the transverse piece rotates together and must be tightened for assembly. This tightening is eliminated in the case of the crosspiece's arched shape.

[0029] As mentioned above, the arched crosspiece 22 is accordingly guided in the installed state through the retaining eye 40 formed from the upper top 38 of the plastic inner container 12. In other embodiments, the retaining eye 40 can also be designed as a bearing journal 50 open on one side (also called hook eye), as in Fig. 9 Here, the arched cross-piece 22 is bridged and secured in the middle from the outside to the inside by a bearing journal 50 which is solidly constructed by a material thickening.

[0030] Different embodiments of the crosspieces 22, 42 allow for different designs of fastening the two ends of the crosspieces 22, 42 to the upper tubular lattice frame 14. In addition to the end-side fastening described, the ends 52 of the crosspiece 22 can also be flattened in a manner known per se, placed around the uppermost horizontal rod of the tubular lattice frame 14 and screwed together by means of a threaded screw 54 below the uppermost horizontal tubular rod 18, as in Fig.10 As is obvious in .

[0031] In a combined form, the crosspiece 22, 42 can be designed as an elastic spring element with two smaller arches with relatively small radii oriented in the vertical plane and one, two or three smaller arches with relatively small radii oriented in the horizontal plane. Such a configuration can be advantageous for a torque-neutral embodiment. The described embodiments of the crosspiece and the fastening possibilities can be easily combined with one another or replaced with one another in the context of the invention (as far as technically feasible).

[0032] Conclusion: Through the design according to the invention of the cross members 22, 42 as elastic spring elements, the upper region of the tubular lattice frame 14 in the case of a pallet container 10 can be protected in a relatively simple form and manner against the adverse effects of transport vibrations and dynamic shock loads and the operational safety when handling filled pallet containers is increased.

[0033] Reference numerals list 10 Pallet Container 12 Plastic inner container 14 Tubular Grid Frame 16 Bottom tray 18 Horizontal tubular rods (14) 20 vertical tubular rods (14) 22 Horizontal piece 24 Spring elements (22) 26 fixed points (22) 28 opposite fixing points (22) 30 Nut(22) 32 Extrusion unit (22) 34 Larger Arches (22) 36 Smaller Arches (22) 38 Top (12) 40 Retaining Eyelets (38) 42 2 arched transverse pieces 44 Internal thread (30) 46 Internal thread (32) 48 thread screw (30,32) 50 Hook eye or bearing journal (38,12) 52 End of cross member (22,42) 54 thread screw (22,42).

Claims

1. A pallet container (10) for storing and transporting liquid or flowable filling materials, comprising a thin-walled rigid plastic inner container (12) made of thermoplastic plastic, a tubular lattice frame (14) consisting of horizontal and vertical tubular bars (18, 20) welded to one another as a supporting jacket tightly surrounding the plastic inner container (12), and a bottom tray (16) on which the plastic inner container (12) is placed and to which the tubular lattice frame (14) is firmly connected, wherein: Two rod-shaped cross members (22) are arranged above the plastic inner container (12) and are fastened with their two ends to two opposite side walls in the upper region of the tubular lattice frame (14). It is characterized in that The two rod-shaped cross pieces (22, 42) are designed as elastic spring elements (24).

2. The pallet container (10) according to claim 1, It is characterized in that The two transverse pieces (22, 42) designed as elastic spring elements (24) are not formed in a non-linear manner but instead each have one or more curved sections.

3. The pallet container (10) according to claim 1 or 2, It is characterized in that The length of the cross piece (22, 42) between its two fixing points (26, 28) is designed to be greater than the direct distance between the two fixing points (26, 28) of the cross piece (22, 42) at its ends in the upper region of the tubular lattice frame (14).

4. A pallet container (10) according to claim 1, 2 or 3, It is characterized in that The crossbar (22) is not designed to be linear but rather arched between its two fastening points (26, 28) and has a relatively large arch (34).

5. A pallet container (10) according to claim 1, 2, 3 or 4, It is characterized in that The cross piece (22) is arched in a horizontal plane when viewed in the installed state, wherein the larger arch (34) is directed outward in the direction of two opposite shorter side walls of the tubular lattice frame (14), wherein the arched cross piece (22) lies flat on the upper roof (38) of the plastic inner container (12) and the larger arches (34) of the two cross pieces (22) are oriented so as to point away from each other.

6. A pallet container (10) according to claim 1, 2, 3, 4 or 5, It is characterized in that The length of the crosspiece (22) between its two fixing points (26, 28) is designed to be between 1% and 5%, preferably 3%, greater than the direct distance between the two fixing points (26, 28).

7. A pallet container (10) according to claim 1, 2, 3, 4, 5 or 6, It is characterized in that The distance between the two fixing points (26, 28) for a standard pallet container with a filling volume of 600, 1000 or 1200 litres is approximately 960 mm and the effective length of the cross-piece (22) is approximately 993 mm.

8. A pallet container (10) according to claim 1, 2, 3, 4, 5, 6 or 7, It is characterized in that The arched crosspiece (22) for standard pallet containers with a filling volume of 600, 1000 or 1200 liters has a larger arch radius of between 300 mm and 700 mm, preferably 500 mm.

9. A pallet container (10) according to any one of the preceding claims 1 to 8, It is characterized in that The two ends of the cross piece (22, 42) are strongly pressed and an internal thread (46) is directly formed into the pressed part (32), and the two ends of the cross piece (22, 42) are firmly screwed at the end side to the upper horizontal or vertical tubular rod (18) of the tubular lattice frame (14).

10. A pallet container (10) according to any one of the preceding claims 1 to 9, It is characterized in that A nut (30) with an internal thread (44) is inserted into each of the two ends of the crosspieces (22, 42) at the end and is screwed securely at the end to the upper horizontal or vertical tubular rod (18) of the tubular lattice frame (14).

11. A pallet container (10) according to any one of the preceding claims 1 to 10, It is characterized in that The two ends of the crosspiece (22, 42) are each screwed at the end to the upper region of two adjacent vertical tubular rods (20).

12. The pallet container (10) according to claim 1, 2, 3, 6 or 7, It is characterized in that The cross piece (42) with two arches is designed nonlinearly between its two fixing points (26, 28) and has at its two ends respectively a smaller arch (36) with a relatively small radius formed downward when viewed in the installed state and is screwed on the end side from below relative to the uppermost surrounding horizontal tubular rod (18).

13. A pallet container (10) according to any one of the preceding claims 1 to 12, It is characterized in that The cross-piece (22, 42) has a round tubular contour with a diameter between 16 mm and 24 mm, preferably 20 mm, and a wall thickness between 0.8 mm and 1.2 mm, preferably 0.9 mm.

14. A pallet container (10) according to any one of the preceding claims 1 to 13, It is characterized in that The cross-piece (22, 42) has a square tubular profile with an edge length of between 14 mm and 20 mm, preferably 16 mm, and a wall thickness of between 0.8 mm and 1.2 mm, preferably 0.9 mm.

15. A pallet container (10) according to any one of the preceding claims 1 to 3, 6, 7, 9 to 11 and 13, It is characterized in that The crosspiece (22) is designed with two or three elastic spring elements oriented in a horizontal plane and having a relatively small curvature and a relatively small radius.

16. A pallet container (10) according to any one of the preceding claims 1 to 3, 6, 7, 9 to 11, 13 and 15, It is characterized in that The crosspiece (42) is designed as an elastic spring element with two smaller arches with a relatively small radius oriented in a vertical plane and two or three smaller arches with a relatively small radius oriented in a horizontal plane.

17. A pallet container (10) according to any one of the preceding claims 1 to 16, It is characterized in that The arched crosspiece (22, 42) is guided in the installed state through a retaining eye (40) formed from the upper top (38) of the plastic inner container (12), and the retaining eye (40) is arranged in the middle of the arched crosspiece (22, 42).

18. A pallet container (10) according to any one of the preceding claims 1 to 16, It is characterized in that In the installed state, the arched cross piece (22, 42) is respectively guided under a hook eye (50) formed from the upper top (38) of the plastic inner container (12), and the hook eye (50) is arranged in the middle of the arched cross piece (22, 42).

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