WO1998058849A1

WO1998058849A1 - Pallets which are provided with wheels and can be coupled one after the other and arranged one above the other

Info

Publication number: WO1998058849A1
Application number: PCT/FI1998/000537
Authority: WO
Inventors: Pekka E. Rapeli
Original assignee: Rapeli Pekka E
Priority date: 1997-06-19
Filing date: 1998-06-18
Publication date: 1998-12-30
Also published as: FI972650A0

Abstract

The invention relates to a transport pallet (1) with a design such that it can be coupled to form a train of transport pallets comprising two or more pallets and can be stacked to form a pile of transport pallets comprising empty pallets, or to form transport pallets on top of each other, which carry a load and a shell covering the load to support the upper transport pallet. The transport pallet is a rectangular plate construction with high loading capacity and having longer sides parallel with the direction of movement of the transport pallet and short sides transverse to the direction of movement of the transport pallet. On the lower surface of the transport pallet (1) of the invention wheels (3) are provided, which can be shifted into upper i.e. rest position, where they are located above the lower surface of the transport pallet or touch this, and back to lower position, i.e. working position, where the transport pallet can move on its wheels (3). The transport pallet also comprises means (6) for shifting the wheels and means (7) for locking the wheels. The wheels including shifting means and locking means are disposed in a separate housing construction (2), which is attached to the ends of the transport pallet.

Description

PALLETS WHICH ARE PROVIDED WITH WHEELS AND CAN BE COUPLED ONE AFTER THE OTHER AND ARRANGED ONE ABOVE THE OTHER

The invention relates to a transport pallet as defined in the preamble of claim 1. The term "transport pallet" denotes transport platforms for various loads, such as single pieces, containers, loaded pallets, etc. which are equipped with wheels or without wheels.

FI Patent Application 945992 deals with a transport pallet design suitable for use in the distribution process on passenger ships, ferries and similar. The transport pallet is not equipped with wheels. It is adapted to be connected with a second identical transport pallet to form a transport pallet cluster consisting of two or three adjacent transport pallets. The load on the transport pallet is surrounded by a shell structure, whose upper surface is equipped with a set of rollers to allow the second transport pallet to be moved on top of the first transport pallet. Even a third transport pallet can be disposed on top of the second transport pallet shell.

An elevator with a longitudinally and transversely operating transport platform on its floor conveys such a loaded transport pallet cluster to a particular storey, where the load is unloaded and moved to its final destinations, the cabins, for instance. The load has anyhow to be unloaded in such a way that the transport means, e.g. a battery-driven truck, moves one transport pallet at a time to a cabin for instance. Such transfer one by one is time-consuming and causes much reciprocating traffic in the ship corridors and entails jams in the lift entrances.

US patent specification 3 488 062 also discloses a wheeled container for transporting goods. To minimise the outer dimensions of the container conveyor, for instance with a view to transport by ship, the wheels have been adapted to be swung aside, thus reducing the height of the container significantly. In the corner area of the container bottom there are still small wheels in working position, some of the wheels rotating in one direction and others in a direction transverse to this. Supported by these small wheels, the container moves on conveyor platforms equipped with rails.

Nevertheless, these known containers are not adapted for such mass transport as large groups of passengers travelling, since these containers cannot be moved successively in a row, nor stacked on top of each other. The purpose of this invention is to provide a transport pallet which essentially eliminates the drawbacks mentioned above. Another purpose of the invention is to provide a transport pallet allowing transport logistics of various goods to be optimised: for instance on ships, luggage, goods relating to provisioning and the like, at airports, passenger luggage to be handled, in commerce, large warehouse goods and in hotels, passenger luggage. In order to achieve these purposes, the transport pallet in accordance with the invention is characterised by the features defined in the characterising clause of claim 1.

Thus, the lower surface of the transport pallet in accordance with the invention is provided with wheels, on which the transport pallet can move on the floor, which enables a train of transport pallets to be formed and such a train to be towed e.g. by means of a truck. In the case of a passenger ship for instance, this allows the suitcases headed for the cabins on both sides of one corridor in a section to be moved and distributed to the cabins in one transport operation from the lift hall to the end of the corridor.

However, the wheels provided on the lower surface of the transport pallet of the invention can be shifted into upper position, i.e. an inoperative position, where they are entirely above the lower surface or touch the lower surface. With the wheels in upper position, the handling and transfer of the pallet can be mechanised and/or automated applying known material handling solutions. In this position, the pallets can be transported on various tracks on the platform, such as roller tracks, conveyor belts, rails, chain railways etc. provided by warehouse automation, e.g. in ship corridors and in and out of elevators for goods. Moreover, the arrangement allows transport pallets to be loaded on top of each other to form a load in two or three layers.

Loading for instance luggage onto transport pallets and moving the pallets in a row in one, two or even three layers towed by a traction engine is an efficient means of transport. The fact that the transport pallets can be removed from the row and freely moved on their own wheels to the desired location, e.g. to a ship cabin, increases the use value of transport pallets significantly and boosts the system for transporting luggage or similar load.

The train of transport pallets mentioned above includes successive transport pallets, whose wheels are in lower position, i.e. in operative position, and on which the transport pallets move. On top of each transport pallet, there may be another or even a third loaded transport pallet. The wheels of these transport pallets are swung into upper position, i.e. rest position, where they do not protrude from the lower surface of the transport pallet. The load on the lowermost transport pallet is surrounded by a shell, whose lower edges engage receiving means provided on the upper surface of the transport pallet, for instance in the way described in FI Patent Application 945992. The upper surface of the shell is equipped with a set of rollers, which makes it easier to move the following transport pallet onto the shell. Thus, the train of transport pallets may comprise several successive transport pallets, each of which supporting, besides its own load and the shell surrounding it, a second and even a third loaded transport pallet.

As the train of transport pallets is dismantled, the uppermost shell is first removed, after which the goods are distributed to their specific cabins and the emptied shells and the transport pallets are assembled into separate clusters. The wheels of the unloaded transport pallets are swung into upper position so as to allow all the empty transport pallets to be assembled into a cluster. Thus clustered, the transport pallets and shells are readily moved to the storeroom reserved for them.

To ensure good controllability, at least one pair of wheels of the transport pallet have a design which is pivotable on the platform. In a preferred embodiment of the transport pallet, a pair of wheels pivotable on the platform is provided at its front edge, while a stationary pair of wheels is provided at its rear edge. Such a transport pallet is easy to move both in a straight direction and in a curved direction. The pairs of wheels at the front edge and the rear edge both having a design pivotable on the platform, controllability is enhanced and the design is particularly suitable for narrow spaces. However, driving in a straight direction, the directional stability is not particularly good, but can be improved by providing one of the wheels with a directional stop.

In a solution comprising three pairs of wheels, the edge wheels are preferably pivotable wheels, while the central wheels are stationary wheels. This is a more expensive solution, which, however, ensures both good controllability and directional stability.

At the front and/or rear edge of the transport pallet, there are preferably two, appropriately even more small wheels, on one hand to make clustering and the transfer of a finished cluster easier, and on the other hand, to help the movement of the transport pallets, especially when the floor surfaces are covered with soft carpets or other special coatings. The transport pallet wheels which can be shifted between a lower and an upper position are preferably placed in couples in the transverse direction, with one pair at each extreme end, and near the side edges of the transport pallet. The wheel mechanisms and their transfer means are disposed within the shell construction, and for this reason the height of the construction is higher than that of the supporting plate of the transport pallet.

On one hand, the dimensions of the frame plate of the transport pallet have been adapted to those of the goods to be transported, and on the other hand, to those of the spaces where the transport pallet will be primarily used, such as the size of an elevator floor and e.g. the corridor width in a ship,. The weight-carrying capacity of the transport pallet is determined by its purpose of use.

The weight-carrying capacity of the transport pallet is preferably conceived to be approx. 2,000 to 3,000 kg and its effective weight-carrying area as approx. 1,200 x 1,600 cm, or 1,200 x 2,400 cm respectively, providing space for two or three pallets with the usual size of 800 x 1200 cm, respectively. The frame plate is preferably made of a sandwich board, e.g. coating plates consisting of an aluminium honeycomb core and aluminium, stainless steel or a composite material and having a thickness in the range from approx. 0.5 to 2.0 mm. Optionally, the frame plate may have the structure of a corrugated sheet, the plate being for instance an extruded aluminium profile or a corrugated sheet assembled by welding, the material being aluminium, zinc coated sheet steel, titanium plate, Rst plate.

The overall thickness of the transport pallet including the wheel housings varies in the range from 50 to 150 mm. The height between the lower surface of the transport pallet and the platform, corresponding to the gap provided by the lowered wheels, should be in the minimum range of 60 to 70 mm. This allows truck forks to be inserted under the tiansport pallet.

The wheel housing construction is manufactured separately and attached to the ends of the frame plate by any suitable means.

Preferred embodiments of the invention are presented below with reference to the enclosed figures, in which

figure la is a top projection of a transport pallet in accordance with a preferred embodiment of the invention, having separate wheel housings including wheel mechanisms at the ends of the front and rear edges, extending from the support plate in the longitudinal direction of the transport pallet, with the wheels in their lower position,

figure lb is a top projection of the transport pallet in accordance with a second preferred embodiment, having at its front end two wheels in their upper position, fitted into a fairly narrow support structure at the centre of the transport pallet, and at the rear end, two wheels in their upper position, fitted into the support structure and extending to the vicinity of the transport pallet sides,

figure lc is a top projection of a transport pallet in a second preferred embodiment, whose rear end is identical to that of the transport pallet of figure la and having at its front end at the longitudinal central axis a relatively narrow wheel housing, into which a wheel mechanism has been fitted with all the wheels in their lower position,

figure 2a shows a lateral vertical section of a transport pallet of the invention, which is equipped with a similar wheel housing and wheel mechanism as the transport pallet of figure la, with the wheels in lower position,

figure 2b shows the same as figure 2a, with the wheels in lower position,

figure 3 shows a lateral vertical section of the transport pallet of the invention, having a wheel mechanism like that of the second embodiment at both ends of the pallet, with the wheels in lower position,

figure 4 is a bottom projection of a transport pallet in the second embodiment, in which the wheel housings including wheel mechanisms are at the ends of the front and rear edges, inside the support plate,

figure 5 is a bottom projection of a transport pallet of a further embodiment, having, besides the wheels at the ends of the front and rear edges, a pair of wheels between these, each wheel being located at the edge of the support plate, within the support plate,

figure 6 is a bottom projection of the transport pallet of a further embodiment, having at its front edge a similar pair of wheels as in the embodiment of figure 5 and at its rear edge five pairs of wheels for movement on special surfaces, figure 7a shows a vertical section of a wheel mechanism of a special type fitted to the extreme edge of the transport pallet, with the wheel of the type pivotable on the platform in its lower position,

figure 7b shows the same as figure 8a, however, with the wheel in its upper position,

figure 8 a shows the same as figure 8 a, however, with the additional wheel mechanism fitted in the centre of the transport pallet, with the wheel in its lower position,

figure 8b shows the same as figure 9a, however, with the wheel in its upper position,

figures 9a-9e show a means of the second embodiment for shifting the wheel from the lower position to the upper position and vice versa, and for locking the wheel in either position, of which

figure 9a is a bottom projection of the rear and front ends respectively of two transport pallets of the invention, interconnected with a pull pin,

figure 9b shows the front and rear end of the transport pallet in a vertical section and a connected combined pull and locking pin, with the pull pin in rest position,

figure 9c shows a shifting means known per se , illustrated in figures 10a and 10b, for shifting the wheel into upper position or vice versa into lower position, with the pull pin in pulling position and the locking pin inserted through two opposite holes in the locking shaft,

figure 9d shows a cross-sectional surface of the locking shaft,

figure 9e shows a combined pull and locking pin,

figures 10a- lOd show a means of the embodiment illustrated in figures 2a and 2b for shifting the wheel from lower position to upper position and vice versa, and for locking the wheel in either position, and also different stages of the position shift, of which

figure 10a is a lateral vertical section of a wheel mechanism, with the wheel in lower position, figure 10b is a vertical section of the wheel meachanism of figure 10a, seen fom the front,

figure 10c is a separate view of a double locking pin,

figure lOd shows the same as figure 10b, however, with the double locking pin in raised position,

figure lOe is a top projection of the wheel mechanism without the double locking pin,

figure lOe shows a top projection of the same wheel mechanism without the double locking pin,

figure lOf shows the same as figure lOe, however, with the double locking pin in the locking position of figure 10a, seen from above,

figures 1 la-1 le show a means of a further embodiment for shifting the wheel from lower position to upper position and vice versa and for locking the wheel in either position,

figure 11a shows a vertical front projection of the wheel mechanism, with the wheel in lower position and with keyholes in the locking pin for the upper and lower position,

figure l ib shows the same as figure 11a, however, with the wheel in upper position marked with a dotted line,

figure l ie shows the same wheel mechanism seen from above (with the protective plate removed) and the locking pin inserted into its hole,

figure l id shows a separate locking pin,

figure l ie is a schematic vertical projection of the locking of the wheel mechanism of figure 11a, showing the locking holes for the upper and lower position formed in the wheel housing construction, with the locking pin visualised in a position locking into the lower position, figures 12a- 13 c illustrate the means of a further embodiment for shifting and locking the wheel in lower or upper position,

figure 12a shows the rear end of the transport pallet of the invention with two wheels not pivoting on the platform fitted into casing-like modules, seen from above, with the wheels in lower position,

figure 12b is an enlarged separate lateral view of the wheel module of figure 12a,

figure 12c is a front view of the wheel module of figure 12b in lower position and marked with dotted lines in upper position, and half-way between the lower position and the upper position,

figure 13 a shows the front part of the transport pallet of the invention and the two wheels pivoting on the platform fitted into cylindrical support modules, in their lower position and swung to the right, seen from above,

figure 13b shows the wheels of figure 13a swung into upper position, i.e. horizontal position, seen from above,

figure 13c is an enlarged separate view of the wheel module of figure 13a, with the wheels in lower position and turned directly to the front, seen from the side,

figure 14a is a schematic view of he transport pallet of the invention, with the wheels in lower position and loaded with luggage and equipped with a shell surrounding the load,

figure 14b shows the same as figure 15a, however, with the wheels of the transport pallet in lower position and the upper surfaces of the two-piece shell equipped with a set of rollers,

figure 14c shows a transport pallet arrangement in two layers, formed of the transport pallets of figures 14a and 14b,

figure 15a shows a train of transport pallets in one layer towed by a tractor, the transport pallets being unloaded stepwise and assembled elsewhere, and

figure 15b shows a train of transport pallets in two layers towed by a tractor, the transport pallet being unloaded stepwise and assembled elsewhere, figure 16a is a top projection of the transport pallet of the invention, loaded with two platforms, and

figure 16b shows the transport pallet loaded with three platforms.

In figure la the transport pallet is marked with reference 1, the wheel mechanism housings with reference 2, the transport pallet wheels with reference 3 and the coupling member of the transport pallet for forming a row of transport pallets with reference 4, and the hole in this with reference 5. The wheel mechanism of figure 1 has the same design as that of figures 2a and 2b and figures 10a- lOd, in which the wheel support beam including the wheels is shifted from lower position to upper position and vice versa.

The embodiment of figure lb includes four wheels, as does the embodiment of figure la. The rear wheels are disposed near the lateral edges of the transport pallet, whereas the two front wheels are fixed to the frame module in the centre. Such a transport pallet has poorer stability than the pallet of figure la, where the wheels are at the outer corners.

Figure lc shows an extreme case, having two wheels at the rear end and only one single wheel in the centre at the front end. This is a more economical solution, which works satisfactorily at least for specific purposes of use.

In figures 2a and 2b the support axis of wheels 3 are marked with reference 6 and the locking pin with reference 7. Shifting the wheels into rest position, where they are located above the lower surface of the transport pallet, is simply effected by releasing the locking pin 7 from its locking position and passing the support axis upwards in guide groove 8 into the receving recess 9 at the upper end of the guide groove, and by returning locking pin 7 into locking position. Both the wheel pairs are attached to a common support axis 6, so that the front wheels can be raised into upper position by bringing the front support axis into the upper recess 9 and the rear wheels accordingy, by bringing the rearmost support axis into its upper recess 9. The wheels are shifted into their lower working position in the inverse order.

The reason why the transport pallet illustrated in figures 2a and 2b has relatively high housings 2 for the wheel mechanisms is that the entire wheel including its support structures is lifted vertically into the housing. Wheel mechanisms of another type require less height, which is more economical. Optimising the transport devices in terms of loading capacity (both regarding weight and volume), space requirement, weight, mobility, transferability, manipulability and costs is of course of vital importance in all the fields of use of the transport pallet.

The wheel housing structure 2 is attached to the support plane of the transport pallet by any known means meeting strength requirements.

The embodiment of figure 3 shows a shifting and locking mechanism for the wheels which requires a very low space. As shown in the figure, the wheel modules do not increase the height of the pallets at all. The wheel modules are located at the outer corners of the transport pallet, within the pallet plane. At the left rear end of the pallet the platform has non-pivotable wheels and at the front end wheels that are pivotable om the platform. The wheels pass into upper rest position about a horizontal axis transverse to the axis of rotation. This wheel mechanism is elaborated in connection with figures 12 and 13.

In the transport pallet of figure 4, wheels 3 are placed at the corners of the support plate, within the support plate. The wheels have a design pivotable upwards and downwards, shown more in detail in figures 7, 8 and 9. At the ends of transport pallet 1, there are also small trains of wheels 10 for vertical handling of the transport pallets. Vertical handling occurs in connection with the dismantling of a train of transport pallets, load shells and transport pallets being released and collected into clusters for storage in any suitable store. In addition, the ends of transport pallet 1 comprise small trains of wheels 11 acting as impact shields at its outer corners.

Figure 5 illustrates a similar transport pallet as figure 4. While the wheels have the same pivotable construction, they project from the support plate of the transport pallet. Rubber guards, fenders 12 are provided at each corner to protect wheels 3. In addition to the four corner wheels, a third pair of wheels is provided at the ends of the transverse axis. These wheels are advantageously non pivotable in the platform, whereas the wheels at the ends are pivotable. This wheel combination yields good controllability and also directional stability for the transport pallet.

Figure 6 shows an embodiment of the transport pallet having two sets of coaxial wheels at the rear end. When the pallets are unloaded and assembled into clusters for storage wheels 44 help moving the pallets vertically. The wheels also makes it easier to move on special surfaces, such as slippery floors, soft carpets, uneven supports, etc. In the figure, the wheels have been turned into upper, i.e. rest position (pallet position). Figures 7a-8b are enlarged views of the wheel mechanism pivotable into upper and lower position, and figures 9a-9e illustrate one solution for shifting and locking the pivotable wheel mechanism.

Figure 7a shows how the flange construction 13 of the wheel rotates on support axis 14. The wheel is pivotable on the platform. To shift the wheel into upper rest position, flange construction 13 is turned 90° counterclock-wise into the positions illustrated in figures 7b and 8b. Figures 7a and 7b show a wheel housing disposed at the end of the transport pallet, from where wheel 3 projects to some extent in its upper position. Figures 8a and 8b show wheel housing 15, which is fitted in the centre of the transport pallet as shown in figure 4.

Means for shifting and locking the pivotable wheels are shown in figures 9-9e. Figure 9a illustrates the end portions of two connected transport pallets. Pull pin 16 is articulated at one end to the end of locking pin 17 and at the other end it is detachably attached to the housing structure 2 of the transport pallet to be connected, figure 9b. Locking pin 17 is illustrated in greater detail in figure 9e. Its vertical locking portion is adapted to pass through the hole in housing structure 2, through two opposite holes 18 in the mantle surface of support axis 14, and further through lower support plate 19. Attached to figure 9a is an enlargement of the hole provided in the upper wall of housing structure 2, through which locking pin 17 passes when locking the wheel into lower or upper position. This hole has the shape of a keyhole and its central axis is at a 45° angle to the transverse direction of the pallet. Locking pin 17 is fitted into this hole at a 45° angle, projection 45 of the locking pin passing through the keyhole, after which the locking pin is turned back 45°, so that the said projection prevents the locking pin from being released from its locking position.

In the centre relative to the longitudinal direction of support axis 14 four holes 18 are provided in the mantle surface at a 90° mutual distance. In the lower, i.e. operative position of wheel 3 locking pin 17 passes through two opposite holes 18 and with the wheel swung up, i.e. in rest position, the locking pin passes through two other opposite holes 18, thus locking the wheel into upper position. In its non- pulling position, the articulated pull pin 16 of locking pin 17 is swung parallel to the support axis and attached to pin 20 in the wheel housing, figure 9b. To change the wheel position, the locking pin is lifted upwards so as to be removed from the holes 18 in the support axis, after which the wheels are pivoted 90 °C and the locking pin is fitted through the second holes 18 and the pull pin is disposed either in pulling position or in rest position. Figures 10a- 1 Of illustrate the means for shifting and locking the vertically upwards and downwards movable wheels. Figure 10a shows the housing structure of the vertically movable wheel 3, which consists of an end wall structure 26 having two receiving recesses for support axis 6 placed above each other and at a mutual distance, lower receiving recess 23 and upper receiving recess 9, inner wall structure 27 and upper wall 25 connecting the wall structures and lower lock plate 28, which is attached to inner wall structure 27. In the gap between the inner wall structure and the end wall structure 26 a guide groove 8 is formed, whose upper end engages the upper receiving recess 9 and whose lower end engages the lower receiving recess 23. In figure 10a the wheel is in its lower position, support axis 6 being in its lower receiving recess 23. A bridge-like locking means 7, figure 10c, whose vertical pillars 24 form a double-pin locking means, locks the support axis into recess 23. The double-pin structure is fitted into position through the opposite openings in the upper wall 25 and in locking plate 28. The opening array 29 in the upper wall 25 can be seen in figure lOe, which is a top projection of the wheel housing including the wheels, and in which the locking means is not represented. In its locking position, locking means 7 is in the opening 30c at the end side of opening array 29. In this position, the end flange at the upper end of pillars 24 is located in an opening 30c of the same size, while the lower part of the pillar is locked into an opening of the same size in locking plate 28, figure 10b.

When one wishes to shift the wheel into its upper position, i.e. rest position, locking means 7 is lifted slightly upwards so that the upper flange of pillars 24 is removed from the opening 30c in the upper wall plate and the thinner waist portion immediately below the upper flange reaches the height of the upper wall plate 25, figure lOd. In this position, locking means 7 can be moved in guide groove space 8 towards the inner wall structure 27, given that the upper waist portion of pillars 24 can run in the waist portion 30b of the opening array 29. With pillars 24 in the inner opening 30a of the opening array 29, the locking means is lowered, so that the upper flange of the pillars passes into opening 30a, the position indicated with a dotted line in figure 10a. This operation provides space in guide groove 8 for the removal of support axis 6 from recess 23 and for moving it in the guide groove into the upper receving recess 9. In order to maintain the correct position of support axis 6 relative to the transverse direction of the pallet, a "Speger ring" 6a for instance has been provided on either side of end wall structure 26. The locking of the support axis into this position is carried out in the inverse order, by lifting locking means 7 upwards, moving it horizontally outwards and lowering it to be locked into opening 30c, figures 10a and lOf. This embodiment of the shifting and locking means is suitable both for wheels which do not pivot on the platform and for wheels which pivot on the platform. The support axis may be a square support axis as illustrated in the figures, or optionally a circular support axis. The support axis may also have a thinner construction, thus reducing the space requirement relative to the direction of movement of the housing structure in the longitudinal direction.

Figures 11a- l ie show means for shifting and locking wheels pivoting on a hinge. Figure 11a shows a wheel 3 pivoting on hinge 33 viewed from the front in lower position. In figure 1 lb the wheel is illustrated with dotted lines in its lifted position and in figure l ie in the same position but seen from above. The locking of the wheel into lifted position takes place by means of locking pin 34, which is pushed through a keyhole-shaped hole 35a in the housing construction and through a bushing 36 fixed to the wheel construction into a receiving opening in the counter- body and is subsequently turned 90° into the position shown in figure l ie, from position 1 to position 2, in which the locking pin is prevented from dropping out of the housing structure. Counter-body 35c prevents the locking pin from pivoting more than 90°. Bushing 36 is fixed to the hinge leaf 37 of hinge 33 facing wheel 3. To shift the wheel into lower position, locking pin 34 is rotated in the opposite direction and removed from bushing 36 and hole 35 a, and in this situation the wheel can be swung down. The wheel is locked into this position by pushing the locking pin through the second keyhole 35b formed in the housing construction and through bushing 36 into the receving opening and by turning the pin 90°. In the embodiment of figures 11, hinge 33 is parallel to the longitudinal direction of the transport pallet. It may also be transverse relative to the said longitudinal direction. In this case, the wheels should have a structure pivoting on the platform.

A transfer means of the hinge type has the major advantage that even a large wheel in its rest position requires but a small space in the vertical direction. In addition, the height of the transport pallet from the platform can be adjusted by adjusting the fixing point of the hinge in the wheel flange construction. In figure 11 the hinge has been attached to the flange edge.

Figures 12a-c, 13a-c and 14a-c show an additional construction for shifting and locking the wheel, in which the wheel pivots about its axis into upper horizontal position and is locked into lower and upper position by means of a locking pin to be pushed through a bushing attached to the wheel construction. This design allows a very low wheel housing construction viewed in the vertical direction. Owing to this design, the overall thickness of the pallet is reduced, which is of the utmost significance. The ground clearance of the pallet is also reduced, even to less than the wheel radius. The design is suitable both for wheels not pivotable on the platform and for wheels pivotable on the platform.

Figure 12a is a bottom projection of the rear end of the pallet, in the housing construction 2 of which are fitted two wheels 3 not pivotable on the platform and pivoting into horizontal position in their axial plane. Locking into either of the two positions, operative position and rest position, is performed according to the same principle as the locking principle described in connection with figures 11. The locking pin is marked with reference 40 and the locking bushing with reference 41. The frame module of the wheel, by means of which the wheel including its axes are attached to housing construction 2 and the pallet frame plate, is marked with reference 42. Figure 12a shows the wheel in its lower working position.

Figure 12b shows an enlarged separate projection of the wheel mechanism of figure 12a. The support axis 46 of the wheel is located lower than the central height of frame module 42. at approx. 1/3 height. In the lower position of the wheel, the wheel protrudes less from below the frame module than the wheel radius, by about half a radius. This means that the ground clearance is very low, which is an advantage in many connections. The upper surface of the freight level from the floor is also low, which is an advantage in terms of stability. Figure 3 shows that the pallet height from the wheel support housings does not increase at all at the pallet ends. The freight surface is a continuous surface at a low height from the platform level.

The swivelling axis 47 of the wheel is located at the same height as the support and rotation axis 46 of the wheel. The rotation axis is mounted onto bearings in the walls of the frame module. The swivelling axis is attached for instance by a locking ring of Seger type to frame module 42, which, in turn, is attached by its upper surface to the frame plate of the transport pallet. The wheel 3 is surrounded by a side frame 48. The locking bushing 41 is fixed to the side frame 48 of the wheel so that its upper surface is near the outer periphery of wheel 3. The wheel is locked into working position with a locking pin 40 passing through the tubular locking bushing 41, the locking pin being inserted through an opening in frame module 40, through bushing 41 and into a hole guide opening 49 provided in the opposite frame module wall. With the locking bushing in the area of the upper part of the wheel, the locking power reaches its maximum, because the lateral frictional forces generated by the wheel produce the greatest torque in this area. Figure 12c is a front view of the same wheel, shown with unbroken lines in its working position. The same wheel is shown with dotted lines turned 45° towards its horizontal position and also in its horizontal rest position. The handle of locking pin 40 can be seen to the right in the figure, in a position locking the wheel into horizontal position.

Figure 13 a shows two wheels 3 which are fitted at the front end of the transport pallet and can be swung on the platform and are pivotable into horizontal position. Viewed in their lower position and in their movement of direction the wheels are turned to the right. On principle, the locking system is the same as that of figure 12a. The frame module 43 of the wheel is cylindrical. The wheel is locked into vertical position by means of a locking pin to be inserted through the locking bushing fixed to the side frame 48 of the wheel. The locking is performed with the aid of holes 50, 51 at opposite points of the walls of the frame module 43, the locking pin passing thorugh one 50 of these and being directed into the other hole 51.

Figure 13b illustrates the wheels of figure 13a in upper horizontal position. The locking into this position is performed with locking pin 40, which is pushed through hole 50" in the front wall of the transport pallet and through holes 50" and 50' in frame module 43 into bushing 41.

Figure 13c shows a vertical side projection of the wheel of figures 13a and 13b. It visualises the small space requirement of the horizontally swung wheel and its small downwards projection from the frame module. The swivelling frame 53 of the wheel is disposed on the upper side of the frame module of the wheel.

Figure 14 shows transport pallets of the invention loaded with suitcases and equipped with shells 38 surrounding the load. To facilitate unloading and storage, the shell is preferably a two-piece shell. On the upper surface of shell 38 of figure 14b a set of wheels 39 is provided, which makes it easier to move the transport pallet to be placed above on top of the load. A combined two-layered tiansport pallet is shown in figure 14.

Figures 15a and 15b show how the transport pallet of the invention is utilised in mass transport of goods. In figure 15a a double-forked tractor tows successive transport pallets moving on their wheels, which are unloaded at the locations of use along their path. The empty transport pallets are assembled into clusters, which are easily pushed e.g. on wheels at their ends, or towed by a tractor, are transferred to the desired location, e.g. an elevator, and from the elevator to the storeroom. A light truck, for instance, moves the transport pallet to a double-forked tractor, in a row behind this. Moving the transport pallets by a fork lift truck or optionally towing them in a row by a tractor is allowed by the fact that the wheels of the transport pallets can be shifted by simple manoeuvres from lower position into upper position, where they are located above the lower surface of the transport pallet, and back to lower position.

In figure 15, a double-forked truck tows two-layered transport pallets, which, as described above, are unloaded along the path. A light truck or similar performs the forming of two-layered transport pallets and a row, and also the unloading of the transport pallets. The row of two-layered transport pallets offers more efficient transport capacity than does the one-layered row of transport pallets described above. The pivotable wheels of the pallets enable the transport pallets to be stacked into a two-layered or even three-layered unit. The wheels of the lowermost pallet are in working position and those of the pallet stacked on top of this are concealed in horizontal position above the lower level of the pallet.

Figure 16a shows the transport pallet of the invention with its wheels swung horizontally and loaded with two transport platforms and containers on top of these.

Figure 16b shows a slightly longer transport pallet, on which three platforms with containers have been loaded.

The design of the transport pallets allows for the space required by the forks of the truck. The truck can lift the transport pallet into its forks from above, behind, or either side, depending on the requirements posed by the traction current of the pallets or the potential it offers. When the transport pallet is moved onto the lower pallet by a truck, or removed from this in the unloading step, the wheels are swung into upper horizontal postion or lower working position respectively.

Claims

1. A transport pallet (1) with a design such that it can be coupled to form a train of transport pallets comprising two ore more pallets and can be stacked to form a pile of transport pallets comprising the empty pallets, or to form transport pallets on top of each other carrying load and a shell covering the load to support the transport pallet on top, the transport pallet having a rectangular plate design with high loading capacity, and having longer sides parallel with the direction of movement of the transport pallet, and short sides transverse to the direction of movement, characterised in that, on the lower surface of the transport pallet (1) wheels (3) are provided to support the transport pallet, and the wheels can be swung into upper position, i.e. rest position, in which they are above the lower surface of the transport pallet or touch this, and back into lower position, i.e. working position, in which the transport pallet can move on its wheels (3), and in that the tiansport pallet comprises means (14; 21; 33; 47) for shifting the wheels and means (17; 24; 34; 40) for locking the wheels.

2. A transport pallet (1) as claimed in claim 1, characterised in that there are at least three wheels (3), one at the front end of the pallet (1) and two at its rear end.

3. A transport pallet as claimed in claim 1, characterised in that there are two wheels (3) in the front close to each other or spaced from each other, preferably at the comers of the pallet, and that wheels are possibly provided also between the front and rear ends.

4. A transport pallet as claimed in any of the preceding claims, characterised in that at least one pair of wheels (3) has been mounted to be pivotable on the platform in its lower position.

5. A transport pallet as claimed in claim 3, characterised in that the transport pallet comprises three pairs of wheels (3), one of which is located at the front edge of the carrying plane, the second at the rear edge of the carrying plane and the third pair mainly in the centre of these, and that at least one, and preferably both of the pairs of wheels at the front edge and the rear edge are pivotable on the platform in their lower position.

6. A transport pallet as claimed in any of the preceding claims, characterised in that the means for shifting each wheel between the upper and lower position comprise a primarily vertical guide groove (8), whose lower end and upper end form receiving spaces (9, 23) for the support axis (6) of the wheel, into which the support axis can optionally be locked by the locking means (7).

7. A transport pallet as claimed in claim 6, characterised in that the support axis (21) of the pair of wheels is adapted to be moved by hand from the lower end of the guide groove (8) to its upper end or vice versa, and that the locking has been adapted to be performed with a locking means (7, 29) movable in the guide groove.

8. A transport pallet as claimed in claim 7, characterised in that the locking means consists of a bridge-like construction (7), whose support pillars (24) are adapted to be locked into either of two positions (30a or 30c) and which can be shifted by hand from one position to the other, one position (30a) involving locking of the support axis (6) at the lower or upper end of the guide groove and the other position (30c) involving providing space for the movement of the support axis.

9. A transport pallet as claimed in any of claims 1-5, characterised in that the means for shifting the wheels between the upper and lower position comprise a flange attachment (13) known per se, which can be pivoted 90° about its axis (14) into upper or lower position respectively, and which can be locked with a locking pin (17) into its upper position and swung into its lower position by releasing the locking.

10. A transport pallet as claimed in claim 9, characterised in that the locking pin (17) is adapted to lock the support axis (14) of the pair of wheels (3) into a given angular position.

11. A transport pallet as claimed in any of claims 1-5, characterised in that the means for shifting the wheels (3) between the upper and lower position comprise a hinge construction (33) and an arrangement (35a, 35b, 35c) comprising a locking pin (34) and a keyhole, by means of which the wheels are locked into upper and lower position.

12. A transport pallet as claimed in any of claims 1-5, characterised in that the means for shifting the wheels (3) between the upper and lower position comprise a swivelling axis (47) which preferably is located in the same horizontal plane as the rotation axis of the wheel (3), however, transverse to this.

13. A transport pallet as claimed in claim 12, characterised in that the wheels (3) are locked into working position by means of a locking pin (40) passing through a bushing (41) attached to the wheel construction of the wheel and attachable to the frame module of the wheel.

14. A transport pallet as claimed in claim 12 or 13, characterised in that a wheel (3) swinging into working or rest position about the swivelling axis is adapted to pivot also about the vertical axis and that the wheel is disposed vertically into a cylindrical frame module (43).

15. A transport pallet as claimed in claim 12, characterised in that the wheel (3) is locked into rest position with a locking pin (40), which passes through a bushing (41) or similar attached to the wheel construction and engages a hole (52) in the wall construction of the transport pallet (1) and holes (50' and 51") in the wheel frame module (43), and that the wheel (3) is locked into working position by means of said locking pin (40), which passes through said bushing (41) or similar and engages holes (50 and 51) in the wheel frame module (43).

16. A transport pallet as claimed in any of the preceding claims, characterised in that the wheels (3) and the means (14; 21; 33) for shifting the wheels and the means

(17; 24; 34) for locking the wheels are disposed in a housing construction, which is fixed to the ends of the support plate and, if necessary, also to the centre of the support plate.

17. A transport pallet as claimed in any of the preceding claims, characterised in that, at the front and/or rear edge of the transport pallet (1), two or more small wheels (10; 44) are provided for handling empty transport pallets in vertical position and for facilititating the pushing of the transport pallets on carpets of various types.

18. A transport pallet as claimed in any of the preceding claims, characterised in that the empty transport pallets (1) can be assembled into solid clusters.

AMENDED CLAIMS

[received by the International Bureau on 18 November 1998 (18J 1.98); original claim 1 amended; remaining claims unchanged (3 pages)]

1. A tiansport pallet (1) with a design such that it can be coupled to form a train of transport pallets comprising two ore more pallets and can be stacked to form a pile of transport pallets comprising the empty pallets, or to form transport pallets on top of each other carrying load and a shell covering the load to support the transport pallet on top, the transport pallet having a rectangular plate design with high loading capacity, and having longer sides parallel with the direction of movement of the transport pallet, and short sides transverse to the direction of movement, characterised in that, on the underside of the transport pallet (1) wheels (3) are provided to support the transport pallet, and the wheels can be swung into upper position, i.e. rest position, in which they are above the surface of the underside of the transport pallet or touch this whereby the underside of the pallet is plane, and back into lower position, i.e. working position, in which the transport pallet can move on its wheels (3), and in that the transport pallet comprises means (14; 21; 33; 47) for shifting the wheels and means (17; 24; 34; 40) for locking the wheels.

2. A tiansport pallet (1) as claimed in claim 1, characterised in that there are at least three wheels (3), one at the front end of the pallet (1) and two at its rear end.

4. A transport pallet as claimed in any of the prceding claims, characterised in that at least one pair of wheels (3) has been mounted to be pivotable on the platform in its lower position.

7. A tiansport pallet as claimed in claim 6, characterised in that the support axis (21) of the pair of wheels is adapted to be moved by hand from the lower end of the guide groove (8) to its upper end or vice versa, and that the locking has been adapted to be performed with a locking means (7, 29) movable in the guide groove.

9. A transport pallet as claimed in any of claims 1-5, characterised in that the means for shifting the wheels between the upper and lower position comprise a flange attachment (13) known er se, which can be pivoted 90° about its axis (14) into upper or lower position respectively, and which can be locked with a locking pin (17) into its upper position and swung into its lower position by releasing the locking.

10. A tiansport pallet as claimed in claim 9, characterised in that the locking pin (17) is adapted to lock the support axis (14) of the pair of wheels (3) into a given angular position.

12. A transport pallet as claimed in any of claims 1-5, characterised in that the means (3) for shifting the wheels (3) between the upper and lower position comprise a swivelling axis (47) which preferably is located in the same horizontal pane as the rotation axis of the wheel (3), however, transverse to this.

14. A transport pallet as claimed in claim 12 or 13, characterised in that a wheel (3) swinging into working or rest position about the swivelling axis is adapted to pivot also about the vertical axis and that the wheel is disposed vertically into a cylindiical frame module (43).

16. A tiansport pallet as claimed in any of the preceding claims, characterised in that the wheels (3) and the means (14; 21; 33) for shifting the wheels and the means

17. A transport pallet as claimed in any of the preceding claims, characterised in that, at the front and/or rear edge of the tiansport pallet (1), two or more small wheels (10; 44) are provided for handling empty transport pallets in vertical position and for facilititating the pushing of the transport pallets on carpets of various types.