WO1981002719A1

WO1981002719A1 - A pallet

Info

Publication number: WO1981002719A1
Application number: PCT/FI1981/000021
Authority: WO
Inventors: P Jaervinen
Original assignee: Ppth Norden Ab Oy; P Jaervinen
Priority date: 1980-03-21
Filing date: 1981-03-19
Publication date: 1981-10-01
Also published as: EP0047768A1; FI58750B; FI58750C

Abstract

A pallet that comprises a bottom section (10), at its both ends fitted with articulating end sections (11a, 11b), which can, for loading the pallet, be tuned to a vertical position, and, when the pallet is unloaded, be tuned against the bottom section (10) of the pallet for minimum space requirements. The pallet has spring devices that comprise a pack or packs of cup springs (20a, 20b) or a pack (41) or packs of leaf springs. The spring organs are connected to have an effect on the lower parts of the ends (11a, 11b) of the pallets in order to, at various turning angles of the ends (11a, 11b), provide an appropriate force in order to ease the raising of the ends (11a, 11b) to an upright position. The spring device comprises a compression spring installed in the corner of the bottom of pallet, the outer end of the compression spring having a roller device (24, 28, 28a, 28b, 29, 30) or a slide fitting. The rolling organ (24) of the roller device or the slide organ contacts a profiled surface (19), arranged in association with the lower end of the end (11a, 11b) of the pallet.

Description

A pallet

The present invention relates to a pallet comprising a bottom section fitted with articulating end sections. For loading the pallet, the end sections can be turned to a vertical position, and, when not loaded, the end sections of the pallet can be turned against the bottom section of the pallet for minimum space requirements. The pallet comprises spring devices that are arranged to produce an effect on said end sections so as to ease the turning of the end sections from the horizontal position to the vertical position.

As to the State of Art, reference is made to British Patents nos. 1,217,334, 1,252,000, 1,266,689 and 1,432,542. The pallets the invention relates to are standardized load carrying units; the length of a 20' pallet in accordance with an I.S.O. standard is 6 058 mm, while its width is 2438 mm, its height is 2591 mm and the inner length of its ends is 5546 mm. Six pallets such as these can be piled on top of each other.

In order to make the pallets take only little space when returned as return freight, their ends are articulatedly fastened to the bottom section of the pallet in order to make it possible to turn the ends parallel with the bottom section. In this position, several pallets can be piled and loaded on top of each other for small space requirecents when returned.

According to the GB patent no. 1,432,542, the collapsing ends of the pallet are fitted with spring devices intended to ease up the turning of the ends from the horizontal position to the vertical position. In accordance with the GB patent referred to above, helical springs are used as said spring equipment for instance in such a way that the springs stretch as the ends are turned from the vertical position to the horizontal position.

A drawback of these previously known spring devices has been, among other things, that the provided spring tension cannot be appropriately controlled for instance in order to. at each phase of the turning process, provide a force suitable from the point of view of the ergonomic performance. Another drawback of the Prior Art has been the complexity and high price of the equipment.

An objective invention is to eliminate the drawbacks mentioned above. For attaining this objective and objectives to be expressed later, the principal characteristic feature of the invention is that said spring equipment comprise a pack or packs of cup springs, a pack or packs of leaf springs, or other similar spring organs, directly or indirectly connected so as to have an effect on the lower parts of the ends of the pallets via profiled surfaces and/or drawing organs or similar in order to create an appropriate force for easying the turning-up of the ends at different turning angles.

The invention will now be described in detail, with reference to the schematic figures in the accompanying drawings, with no intention to restrict the invention to these details.

Figure 1 is a side view of a pallet in accordance with the invention.

Figure 2 is a plan view of a pallet shown in figure 1.

Figure 3 is a pallet shown in figures 1 and 2 seen from the direction of the end.

Figure 4 is a parallel-perspective illustration of a spring device used in the invention.

Figures 5 and 6 show the same as figure 4, figure 5 illustrating the spring device in the position where the end is turned to an upright position, and figure 6 illustrating the spring device in the position where the end is turned to a horizontal position.

Figure 7 shows an axial section view of a spring device illustrated in figures 4, 5 and 6, in the position of figure 5.

Figure 8 shows section view VIII-VIII in figure 7. Figure 9 shows such an application of the invention in which there is one pack of leaf springs for each end.

Figure 10 shows such an application of the invention, corresponding to figure 9, in which a pack of leaf springs is used in each corner of both ends.

Figure 11 shows another application of the invention, in which there is a pack of leaf springs connected with a contact surface located in the lower end of the end post via a roll or similar.

A pallet illustrated in figures 1, 2 and 3 comprises a bottom section and end sections 11a and llb articulatingly fastened to the ends of the bottom section. In figure 1, phantom lines show one end section 11a' when turned against bottom 10 around pivot 12. By turning both ends 11a and lib against bottom section 11, the pallet is brought into such a configuration in which the pallet takes little space when returned, and in which several pallets are piled on top of each other and locked together.

In each corner of the bottom section of the pallet there is a standardized corner piece 14, and at the top ends 11a, llb there are similar corner pieces 15, which have standard-type openings at which the pallet-carrying equipment grips the pallet and by means of which the pallets are located on top of each other and/or side by side in cargo compartments.

A favourable embodiment of the invention will now be described with reference to figures 4 to 8. A spring device is arranged in association with each pivot pin 12, near articulation flanges 13a and 13b. Spring device 20 will be located in the corner of frame beams 16, 17 and 18 of the pallet, and, as visualized in figures 7 and 8, it comprises two parallel packs of cup springs 20a and 20b, in which there are several cup springs 31 one after another on guide pins 26 and 22b fastened to flange 32. A pressure plate 27 with holes 27a and 27b for guide pins 26a and 26b have been arranged in association with the outer ends of guide pins 26a and 26b. Axle pin 28, on which roll 24 is supported by needle bearing 30, is fastened to pressure plate 27, between flanges 28a and 28b. Roll 24 contacts profiled plate 19, fastened with several flanges 21 in association with flange 13b. In addition to profiled plate 19, roll 24 contacts slide plate 22, fastened at its one end in association with the frame beams of the pallet, and suspended at its other end with cup springs 25.

Figure 7 shows shim pieces 32 that can be installed under guide 33, behind support plate 32a. Shim pieces 32 are for adjusting the tension of spring packs 20a, 20b and it is possible to use one or more shim pieces, or shim pieces of different thicknesses.

Via profiled plate 19 and roll 24, glide plate 22 takes the vertical forces the spring device is subjected to. For this purpose there is, at the outer end of glide plate 22, a cup spring 25 or a similar spring. The glide plate can, within certain limits, bend against the force of this spring when being submitted to vertical forces.

In figures 5 and 6, spring 20 is shown in its longest position; now the end in question is in the upright position. As shown in figures 5 and 7, in profiled plate 19 there is a recess 19a or similar. This is for producing a certain locking force when required for keeping the end in the upright position. As one begins to turn the end from the position of figures 5 and 7, profiled plate 19 compresses spring packs 20a and 20b as roll 24 rotates on the outer surface of profiled plate 19 and slides along slide plate 22. In the position of the vertical posts and their flanges 13a' and 13b' of figure 4, the ends having been turned 10 to 15 , the center of gravity of the ends is at pivot pins 12. As the ends are turned further down, springs 31 are compressed to position 20" shown in figure 6 so that the flanges of the posts will be in position 13a", 13b", and roll 24 will be in posi tion 24".

The curvedness and shape of profiled plate 19 can be so arranged as to provide a suitable force for lifting up the ends in every phase of the lifting operation. The curvedness and shape of profiled plate 19 or similar can be arranged for instance in such a way as to maintain the force needed for lifting up the ends constant at least near the extreme positions of the ends. In any case a spring device in accordance with the invention makes it, at every phase of the raising and lowering operation, possible to appropriately select the force that tends to raise the ends.

Figures 9, 10 and 11 illustrate some inventive solutions, based on the use of a pack of plate springs or similar springs for easying the operation of the articulating ends of a pallet.

As shown in figure 9, a pack of plate springs 41, fastened at its center with supporting devices 40 to the bottom of the pallet, is installed within the bottom 10 of the pallet. Wire ropes 42a, 42b, by means of which plate spring pack 41 is in functional connection with end posts 11a of the pallet, are fastened to both ends of plate spring pack 41. At 43, wire ropes 42a and 42b or drawbars of similar function are fastened to' posts 11a. At the bottom end of post 45 there is a profiled surface 45, whose radial distance R from the pivot pin 12 is made to continuosly grow as the end posts 11a are turned downwards. Thus, in the lower positions of the ends, the force easying the raising operation is made higher as the moment arm R of the force of spring device 41, 42 gradually grows as the end turns downwards. As shown in figure 9, wire ropes 42a, 42b have tension devices known as such by means of which the force reducing the weight of an end can be preadjusted as desired. Another favourable feature of an application illustrated in figure 9 is that only one pack of plate springs 41 is required for providing the weight-reducing force for both uprights of an end.

According to figure 10, each upright of both ends 11a, lib have a pack of plate springs 51 of their own, fastened by supporting organs 50 in association with bottom 10 of the pallet. Wire rope 52 or a drawbar, fitted with a tension item 54, is fastened to plate spring pack 51 or to a similar spring. At 53, wire rope 52 or similar is fastened to the lower end of end post 11a. At the lower end of the end post there is a profiled surface 55, whose function corresponds to the function of profiled surface 45 of figure 9. When using stiff drawbars instead of wire ropes 42, 52, profiled sur faces 45, 55 can not be used.

According to figure 11, a pack of plate springs 61 is installed near the bottom end of each four end post 11a, while the pack of plate springs 61 is, by means of organs 60, attached in association with for instance the side beams of the pallet. A rotating roll 62 or similar sliding organ, contacting the profiled surface 65 of the lower end of post 11a, is installed to the outer end of the plate spring pack 61. The curvedness of profiled surface 65 is selected according to same principles as the curvedness of the profiled plate 19 of the version illustrated in figures 4 to 8. In the profiled surface 65 there can be a specially shaped portion 65' that provides for an appropriate weight-reducing force in the down position of the ends.

According to the invention, a spring device of a relatively simple structure and with essentially improved adjusting facilities have been created in order to reduce the weight of the ends of a pallet. The equipment in accordance with the invention can also be brought about in such a way that they can be installed within protected compartments in the frame structures of the pallet so as to avoid damages.

The various details of the invention may vary within the inventional idea as defined in the following claims.

Claims

1. A pallet that comprises a bottom section (10), at its both ends fitted with articulating end sections (11a, llb) of the pallet, which end sections (11a, llb), can, for loading the pallet, be turned to a vertical position, and which end sections (11a, llb), can, when the pallet is unloaded, be turned against the bottom section (10) of the pallet for minimum space requirements, which pallet comprises spring devices (20; 41; 51; 61) that are arranged to produce an effect on said end sections so as to ease the turning of the end sections from the horizontal position to the vertical positionj wherein said spring devices comprise a pack or packs of cup springs (20a, 20b), a pack

(41) or packs of leaf springs, or similar spring organs, directly or undirectly connected to have an effect on the lower parts of the ends (11a, llb) of the pallet via profiled surfaces (19; 45; 55; 65) and/or draw organs or similar in order to, at various turning angles of the ends (11a, llb) provide an appropriate force in order to ease the raising of the ends (11a, llb) to an upright position.

2. A pallet in accordance with claim 1, wherein said spring organ comprises a compression spring installed into the corner of the bottom of the pallet, the outer end of the compression spring having a roller device (24,28, 28a, 28b, 29, 30) or a slide fitting of the same function as the roller device, and that the rolling organ (24) of said roller device or the similar slide organ contacts a profiled surface (19), arranged in association with the lower end of the end (11a,. llb) of the pallet at a certain distance from the pivot pin (12) of the ends (11a, llb).

3. A pallet in accordance with claim 2, wherein said compression spring (20) comprises several cup springs (31) one after another.

4. A pallet in accordance with claim 2 or 3, wherein the spring device

(20) comprises at least two parallel compression spring devices, preferably packs of cup springs (20a, 20b), which spring devices are installed on guide pins (26a, 26b), and wherein a guide plate (27), in association with which there is a roller organ (24) or a slide organ having the same function as the roller organ (24), is installed in association with the outer end of said guide pins (26a, 26b).

5. A pallet in accordance with claim 4, wherein underneath the spring device (20) there is a plate section (22), which the roller organ (24) or similar contacts, and which plate section (22) is, at its one end, fastened in assocation with the frame structures of the bottom, and, at its other end, equipped with e. spring organ (24).

6. A pallet in accordance with claim 2,3,4 or 5, wherein the curved ness of said profiled surface (19) is so selected as to provide a suitable force for easying the turning-up of the ends (11a, llb) in various phases of said turning-up process.

7. A pallet in accordance with claim 1, wherein said spring device comprises one or more packs of plate springs (41, 51, 61).

8. A pallet in accordance with claim 7 or 8, wherein said spring device comprises a plate spring pack (41) of its own for both ends (11a, lld) which is, at its center, fastened in association with the bottom (10) of the pallet, and whose two ends are, by means of a wire rope (42a, 42b) or a drawbar of similar function, connected to the lower parts (43) of the ends (11a, llb) (figure 9).

9. A pallet in accordance with claim 7 or 8, wherein said spring device comprises a plate spring pack of its own (51), for each bearing point of the lower ends of the end sections, which plate spring pack (51) is, by means of a wire rope (52) or a drawbar of similar function connected to the lower part (53) of an end (11a) of the pallet (figure 10).

10. A pallet in accordance with claim 7,8 or 9, wherein said draw organs (42a, 42b; 52) are connected in association with the profiled surfaces (45; 55) of the lower parts of the end sections, and wherein said profiled surfaces (45; 55) are so shaped as to make the distance (R) between the contact point of the draw organs (42a, 42b; 52) and the profiled surface (45; 55) and the pivot pin (12) of an end vary as a function of the turning angle in such a way that a suitable weight-reducing force is provided by the spring force available at each moment at various turning angles of the end sections.

11. A pallet in accordance with claim 7, wherein said spring device comprises a pack of leaf springs (61), whose outer end has a roller organ (62) or a slide organ of the same function, which contacts the profiled surface (65) of the lower end of the end section.

12. A pallet in accordance with claim 11, wherein said profiled surface (65) is so shaped as to make the distance (R..) between the point of influence (62) of the spring (61) and the pivot pin (12) of the end increase, principally continually, as the end is turned downwards.