Transport apparatus and method for transporting a load

Abstract

The invention relates to a transport apparatus (1) for a load, comprising a lifting plate (15) movable with respect to a chassis (12) by means of a first motion mechanism (20) between a lowered position and an elevated position, and wheel assemblies (30) movable with respect to the chassis (12) between a retraced first position and an advanced second potion by means of a second motion mechanism (20') The transport apparatus (1) is configured to be movable into and through a cavity in the load when at least one of: the lifting plate (15) is in the lowered position; and the wheel assemblies (30) are in the retracted first position.

Description

[0001] TRANSPORT APPARATUS AND METHOD FOR TRANSPORTING A LOAD

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a transport apparatus for a load and a method for transporting a load. More specifically, the invention relates to a transport apparatus having a top face for abutting against a load, wherein an elevation of the top face above a plane that in use of the transport apparatus supports the transport apparatus, is adjustable.

[0004] BAKGROUND OF THE INVENTION

[0005] It is common to stack load or cargo on pallets, in for example factories, warehouses or in trucks for transportation. The pallets are usually lifted from the plane and transported using pallet transporters such as hand pallet trucks or forklifts. Common to these pallet transporters is that they require an area around the pallet in order to lift the pallet and move it around. Usually, the pallet transporters are limited to transport one pallet at the time. However, there are forklifts that may transport several pallets at the time, either by longer forks or a second set of forks. These types of forklifts typically require even more space around the pallets to be able to transport the pallets.

[0006] Publication EP2837545A2 discloses a conveying unit for conveying loaded or unloaded carriers. The conveying unit comprises a chassis which is movable on ground rollers, a support element carried by the chassis, which support element is liftable or lowerable with respect to the chassis, and a drive system by means of which at least one of the bottom rollers can be driven. The drive system comprises at least one drive assembly with a one- piece housing unit which supports the at least one drivable base roller and carries with it at least one drive device for this base roller. The support element is coupled to the drive

[0007] P31278PC00_Description and claims for PCT assemblies.

[0008] Publication DK2772407T3 discloses a transportation device having a supporting element comprising a supporting part operatively connected to a wheel assembly, wherein the supporting part is raised and lowered with respect to the wheel assembly.

[0009] Publications EP3205620A1 and EP2942313A1 disclose similar transportation apparatus as DK277240T3.

[0010] Publication WO2018211481A1 discloses an apparatus capable of entering a cavity of a pallet with the ultimate purpose of lifting it from the ground and moving or reorienting it before placing it back onto the ground. The apparatus comprises at least two drive units, accompanied and mounted into at least two separate but connected structures to form a single device.

[0011] Publication DE102007015095A1 discloses an apparatus for lifting and moving a pallet. The apparatus comprises a lifting platform arranged on a chassis fitted with rollers. The apparatus consists exclusively of mechanical elements so that it is maintenance free, robust, and inexpensive to manufacture.

[0012] WO 2020 / 179386 A1 discloses a transport device comprising a vehicle body portion, and two driving wheels arranged at a mutual distance along the width of the vehicle body portion, at the centre of the vehicle body portion. The transport device further comprises a plurality of auxiliary wheels and a plurality of elevating plates.

[0013] US 2021 / 0339993 A1 discloses a carrier comprising a housing with elevator units, a control unit, a plurality of driving wheels, a plurality of auxiliary wheel units and a plurality of elevator mechanisms.

[0014] US 2021 / 0061629 A1 discloses a guided vehicle which includes a vehicle having a plurality of wheels, a lift unit, a bumper, an extension detector, and a bumper controller. The vehicle is movable in at least a first direction. The lift unit is provided in the vehicle and lifts an object from below the object.

[0015] Publication WO2023 / 191635 A1 discloses a transport apparatus for a load. The transport apparatus comprises a chassis and a lifting plate. The chassis has a length and a width, and comprises: at least one lifting mechanism configured for moving the lifting plate between a lowered position and an elevated position in operational use; and a steering mechanism comprising at least two wheel assemblies at a mutual distance along the

[0016] P31278PC00_Description and claims for PCT length of the chassis, wherein at least one of the at least two wheel assemblies is operatively connected to a drive motor for allowing steering of the transport apparatus; and a control unit for controlling the drive motor and the lifting mechanism. The transport apparatus is configured to be movable into and through a cavity in the load when the lifting plate is in the lowered position. A distance between a lower portion of the chassis and a plane supporting the transport apparatus in use, is constant.

[0017] Publication EP3426593B2 discloses driverless transport vehicle for conveying a load support, comprising: a chassis; a load-carrying unit that is connected to the chassis; a lifting unit for lifting the load-carrying unit relative to the chassis, the chassis having two individual chassis units that each comprise at least one wheel unit, the chassis units being interconnected by means of the load-carrying unit. Bearing devices are arranged between the chassis units and the load-carrying unit such that the chassis units are each movable relative to the load-carrying unit. The bearing devices are arranged between the chassis units and the load-carrying unit such that the chassis units can each be tilted relative to the load-carrying unit about transverse axes of the chassis units extending substantially perpendicularly to the longitudinal axes.

[0018] Publication JP20003002190A discloses an automatically guided vehicle configured for lifting and transporting a load, wherein a bumper device is provided to prevent collisions with obstacles.

[0019] Publication US10773935B2 discloses a conveying apparatus that includes a base, wheels, a lifter, a lower side distance detection unit, and a control unit. The wheels are connected to the base via a suspension mechanism and is rotatable. The lifter is able to be lifted and lowered with respect to the base in a direction of a conveyance target.

[0020] SUMMARY OF THE INVENTION

[0021] The invention has for its object to remedy or to reduce at least one of the drawbacks of the prior art, or at least provide a useful alternative to prior art.

[0022] The object is achieved through features, which are specified in the description below and in the claims that follow.

[0023] The invention is defined by the independent patent claims. The dependent claims define advantageous embodiments of the invention.

[0024] In a first aspect the invention relates to a transport apparatus for a load. The transport

[0025] P31278PC00_Description and claims for PCT apparatus comprises:

[0026] - a chassis having a length and a width;

[0027] - at least one lifting plate having a top face for abutting against a load; and

[0028] - at least two wheel assemblies at a mutual distance along the length of the chassis, wherein at least one of the at least two wheel assemblies is operatively connected to a drive motor, and at least one of the wheel assemblies comprising a steering mechanism for allowing steering of the transport apparatus;

[0029] The chassis comprises: a motor operated first motion mechanism operatively connected to the lifting plate, and configured for moving the lifting plate relative to the chassis between a lowered position and an elevated position; a motor operated second motion mechanism operatively connected to the wheel assemblies, and configured for moving the at least two wheel assemblies relative to the chassis between a retracted first position, and an advanced second position wherein, as compared with the retracted first position, a clearance between a lowermost portion of the chassis and a plane that in a position of use supports the transport apparatus, is increased; and a control unit for controlling the drive motor and the motion mechanism, wherein the transport apparatus is configured to be movable into and through a cavity in the load when at least one of: the lifting plate is in the lowered position; and the wheel assemblies are in the retracted first position.

[0030] It should be understood that the transport apparatus allows for moving the lifting plate relative to the chassis in both directions, i.e. to and from the elevated position, and for moving the at least two wheel assemblies relative to the chassis, i.e. to and from the advanced second position. Allowing movement of both the lifting plate and the chassis, has the effect that the transport apparatus has an improved flexibility with respect to maximum and minimum elevation of a top surface of the lifting plate, as compared with the transport apparatus disclosed in WO 2023 / 191635 A1.

[0031] Contrary to the invention disclosed in WO 2023 / 191635 A1, a distance or free space between a plane supporting the transport apparatus and a lowermost portion of the chassis, is adjustable. An adjustable distance of said free space is particularly advantageous when the transport apparatus is moved on an uneven plane, when there is a break in the plane for example between a substantially horizontal first surface portion to a second surface portion being inclined with respect to the first surface portion, and when the transport apparatus passes a raised obstruction.

[0032] P31278PC00_Description and claims for PCT In one embodiment, the first motion mechanism is configured for moving the lifting plate relative to the chassis simultaneously with the second motion mechanism moving the at least two wheel assemblies relative to the chassis.

[0033] In an alternative embodiment the second motion mechanism is configured for activating movement of the wheel assemblies towards the advanced second position before the lifting plate is activated towards the elevated position by means of the first motion mechanism. An advantage of this alternative embodiment is that the transport apparatus can pass into a cavity of a load wherein an entrance of the cavity comprises an obstruction. Some types of pallets comprises a board or plank abutting against a supporting plane. Such a board or plank may represent an obstruction with respect to a free space to a lowermost portion of the chassis of the apparatus. By moving the wheel assembly at least towards the advanced second position by means of the second motion mechanism and keeping the lifting plate in the lowered or substantially lowered position, the transport apparatus may pass into the cavity.

[0034] In still another embodiment the first motion mechanism is configured for activating the lifting plate towards the elevated position before the wheel assemblies are activated towards the advanced second position by means of the second motion mechanism.

[0035] Any order of activation of the lifting plate and the wheel assemblies may be mechanically controlled. The transport apparatus may comprise a mechanical delay mechanism to control an order of activation of the lifting plate and the wheel assemblies. A mechanical delay mechanism allows simultaneous activation of the first motion mechanism and the second motion mechanism, while at the same time a movement of the lifting plate and the wheel assembly with respect to the chassis, is commenced differently, i.e. one before the other.

[0036] In one embodiment the first motion mechanism is configured for being operated independently of the second motion mechanism.

[0037] The lifting plate may cover a top side of the chassis. This leads to more stability when lifting and lowering a load as the load will be evenly distributed on the area of the lifting plate. In one embodiment, the lifting plate comprises side portions that enclose and slid- ingly abuts side portions of the chassis. This has the effect of providing a very stable transport apparatus. In one embodiment, at least side portions of the chassis are fully covered by side portions of the lifting plate when the lifting plate is the lowered position.

[0038] In one embodiment, the transport apparatus comprises a cleaning device configured for

[0039] P31278PC00_Description and claims for PCT removing loose debris being on a base in front of the wheel assemblies. The cleaning device may comprise at least one of a broom and a plough. Preferably the cleaning device is secured to a portion of the wheel assembly. Securing the cleaning device to a portion of the wheel assembly is advantageous in that the cleaning can be in contact with a plane supporting the transport apparatus independently of a position of the chassis and the lifting plate.

[0040] The effects of the features of the transport apparatus in accordance with the invention are as follows. First of all, the transport apparatus can be easily used to transport loads or cargos having a suitable cavity. The load may typically be a load carrier such as a pallet, with or without an added load. The transport apparatus may first be driven into a cavity in the load while at least one of the lifting plate and the wheel assembly is in the lowered position and retracted first position, respectively. When the transport apparatus is within the cavity, one or both of the first motion mechanism and the second motion mechanism may then move the lifting plate towards the elevated position. It should be noted that the elevation of the lifting plate depends also on an elevation of the chassis with respect to the plane which is controlled by the second motion mechanism that controls the position of the wheel assembly. When the lifting plate is sufficiently elevated, the load is lifted from the plane. Depending on the configuration of the transport apparatus, the second motion mechanism can be activated to bring the wheel assemblies to their advanced second position to lift the load from the plane. While the load is lifted from the plane, the transport apparatus may move the load to a desired location where at least the first motion mechanism may lower at least the lifting plate to the lowered position to lower the load at least towards the plane. Depending on the configuration of the transport apparatus, the second motion mechanism can be activated to bring the wheel assemblies to the retracted first position to put the load on the plane when the transport apparatus has arrived the desired location.

[0041] Furthermore, the transport apparatus is configured to be movable into and through a cavity in the load. This feature has several advantages. Firstly, the transport apparatus can be positioned completely underneath the load before lifting and transporting it. This means that the transport apparatus according to the invention does not need an area around the load in order to lift it and manoeuvre it. A second advantage of the transport apparatus being movable through a cavity in the load, is that several transport apparatuses can be used to move a load each, at the same time. A row of transport apparatuses can be moved underneath a row of loads so that each transport apparatus is underneath a respective load. The loads can be simultaneously lifted and transported, in a trainlike man-

[0042] P31278PC00_Description and claims for PCT ner, to a desired location. More than one row of loads can also be moved simultaneously.

[0043] This is an advantage for example when unloading a truck where the cargo is stored on pallets. A row, or several rows of transport apparatuses can be driven into a cargo space of the truck, lift the pallets and move the pallets to a desired location inside or outside of the cargo space. The truck is in this way unloaded in a single operation. This also applies to loading a truck with pallets. A plane of a truck may be at an elevation that typically is at a higher elevation than a plane or ground onto which the load is to be transported. Therefore, the load is moved via a ramp to the ground having a different inclination than that of plane of the truck. By lowering the wheel assembly with respect to the chassis of the transport apparatus, a clearance between a lowermost portion of the chassis and the plane is increased. An increased clearance will facilitate passing of a “convex” break between the plane of the truck and the ramp, and also passing of the transport apparatus past the “concave” bordering between the ramp and the ground onto which the transport apparatus is moved.

[0044] Due to the transport apparatus being movable into and through a cavity in a load, loads can be stored in a more compact manner. There is no need for an area around a load for lifting it, and several loads are movable at the same time, as explained above. This is an advantage in warehouses where cargos or loads are stored on pallets. Typically, the pallets are stored in rows with spaces between them, so that a pallet transporter, for example a forklift, may move between the rows, lift a pallet, and move it. When using the transport apparatus according to the first aspect of the invention, there is no need for space between rows of pallets for the transport apparatus to be moved around. The transport apparatus can be driven underneath and through pallets to the next desired pallet in the row, instead of beside them. This enables construction of a space saving storage system, where the pallets may be stored more tightly.

[0045] Throughout the description and claims, the wording “lowered position” may be the lowest possible position of the lifting plate with respect to the chassis, or it may be higher than the lowest possible position of the lifting plate with respect to the chassis.

[0046] Throughout the description and claims, the wording “elevated position” may be the highest possible position of the lifting plate with respect to the chassis, or it may be lower than the highest possible position of the lifting plate with respect to the chassis.

[0047] Throughout the description and claims, the term “between a retracted first position and an advanced second position” means any position of wheel assemblies between and includ-

[0048] P31278PC00_Description and claims for PCT ing the extreme positions of the wheel assemblies relative to the chassis.

[0049] Throughout the description and claims, the word “load” must be interpreted as any type of load with a suitable cavity for the transport apparatus to be moved into and through. The load may be a load carrier, such as a pallet or a skid or a skid pallet, for example a so- called Euro-pallet. The load carrier will hereinafter be denoted pallet for simplicity. The load may also be a storage unit such as a crate. The load carrier or the storage unit may carry a cargo or a load, or it may be empty. The pallet may have bottom decks.

[0050] Throughout the description and the claims, position indications such as «upper» and «lower», «top» and «bottom», or «horizontal» and «vertical», etc., denotes the position the apparatus has in the subsequent figures, which is also a natural or practical functional position of the apparatus.

[0051] In embodiments where the chassis comprises several first motion mechanisms, each motion mechanism may lift one lifting plate each, preferably in a substantially paralell movement. The several first motion mechanisms may also be connected to the same lifting plate.

[0052] According to the invention, at least one of the at least two wheel assemblies is operatively connected to a drive motor. In an embodiment of the invention, the at least one wheel assembly being operatively connected to the drive motor may be pivotably connected to the chassis for allowing steering of the transport apparatus.

[0053] The at least one of the at least two wheel assemblies may comprise one wheel operatively connected to a drive motor and being pivotably connected to the chassis.

[0054] By the term pivotably is meant that the wheel assembly or a wheel comprised within the wheel assembly is turnable around an axis being perpendicular to the axis of rotation of the wheel.

[0055] In an embodiment according to the invention the at least two wheel assemblies are operatively connected to a drive motor and are pivotably connected to the chassis for enhancing steering of the transport apparatus.

[0056] The at least two wheel assemblies may each comprise one wheel operatively connected to a respective drive motor and being pivotably connected to the chassis.

[0057] In an embodiment according to the invention the at least two wheel assemblies are pivotable over at least 90 degrees to obtain movability and rotatability in a two-dimensional

[0058] P31278PC00_Description and claims for PCT plane supporting the transport apparatus. The advantage of this feature is that the transport apparatus can be moved and rotated in any x- or y-direction relative to a two- dimensional plane supporting the transport apparatus, for example the floor of a warehouse or storage facility. In such an embodiment, the apparatus is movable in a direction parallel to the length of the apparatus, in a direction perpendicular to the length of the apparatus, and in any direction therebetween.

[0059] At least one of the at least two wheel assemblies may comprise a pair of mutually spaced, parallel wheels. The advantage of the pair of mutually spaced wheels is that the steering of the direction of the wheels may be done with two drive motors connected to a respective wheel in the pair.

[0060] In one embodiment, both or all of the at least two wheels may comprise a pair of mutually spaced, parallel wheels.

[0061] In another embodiment of the invention, the steering mechanism comprises at least one first wheel assembly and a second wheel assembly arranged distant from the first wheel assembly along the length of the chassis. The first wheel assembly may comprise two wheels, wherein each wheel being operatively connected to a respective drive motor, wherein an axis of rotation of one of the wheels in the first wheel assembly is perpendicular to an axis of rotation of the other wheel in the first wheel assembly, and wherein the wheels in the first wheel assembly are liftable and lowerable independently of each other.

[0062] The two wheels in the first wheel assembly may be lowered so that they are in contact with the plane. They may also be lifted so that they are not in contact with the plane. When one of the wheels in the first wheel assembly is lowered to the plane, the other wheel in the first wheel assembly may be lifted from the plane, so that the transport apparatus may be driven in the direction in which the lowered wheel is rotating. To change the direction of the transport apparatus, the wheel is lifted from the plane and the other wheel is lowered to the plane.

[0063] Each wheel in the first wheel assembly may comprise a pair of mutually spaced, parallel wheels, wherein at least one wheel in each pair of wheels is operatively connected to a respective drive motor, and wherein the pairs of wheels are liftable and lowerable independently of each other.

[0064] The axis of rotation of one of the wheels in the first wheel assembly may be parallel to the length of the chassis. The other wheel in the first wheel assembly may be parallel to the

[0065] P31278PC00_Description and claims for PCT width of the chassis.

[0066] In an embodiment of the invention, the second wheel assembly is identical to the first wheel assembly. The advantage of this feature is that the transport apparatus can be moved and rotated in any x- or y-direction relative to a two-dimensional plane supporting the transport apparatus, for example the floor of a warehouse or storage facility. The apparatus is movable in a direction parallel to the length of the apparatus, in a direction perpendicular to the length of the apparatus, and in any direction therebetween.

[0067] In an embodiment according to the invention, the length of the chassis is longer than the width of the chassis. This is advantageous for example if the load to be transported comprises an oblong cavity. A pallet, such as a Euro-pallet, is provided with oblong cavities. The transport apparatus may be configured to fit within one of the cavities in for example a Euro-pallet. Two transport apparatuses can be used to easily transport a Euro-pallet by being moved into a respective cavity, and then activating at least the first motion mechanism to move the lifting plates into the elevated position to lift the pallet.

[0068] The first motion mechanism operatively connected to the lifting plate may comprise two or more first motion mechanisms. The two or more first motion mechanisms may be mutually spaced along the length of the chassis. Two or more first motion mechanisms may facilitate the lifting of the load as the load will be lifted from several points. The lifting and lowering of the load may be more stable. Two or more first motion mechanisms may also lift a heavier load, or the lifting capacity of each first motion mechanism may be reduced.

[0069] In an embodiment according to the invention, the transport apparatus comprises at least one biasing means extending between a portion of the chassis and the lifting plate. The biasing means may be a spring. The biasing means may facilitate the lifting of the lifting plate to the elevated position by the first motion mechanism, especially at the start of the lifting process. Additionally or alternatively, the transport apparatus may comprise at least one biasing means arranged between a portion of the wheel assembly and the lifting plate such that the biasing means may exert a force therebetween. Such an additional or alternative biasing means may facilitate the lifting of the lifting plate to the elevated position by the first motion mechanism, and facilitate bringing the wheel assemblies towards their advanced second position, especially at the start of the motion process.

[0070] The transport apparatus may further comprise at least one sensor. The at least one sensor may comprise a distance detector, which is advantageous for preventing collisions. The at least one sensor may comprise a sensor for detecting visual id tags or RFID (Radio

[0071] P31278PC00_Description and claims for PCT Frequency Identification) tags. It is advantageous for the transport apparatus to read visual id tags, such as QR codes or barcodes, or RFID tags to recognise loads marked with such tags. Furthermore, the at least one sensor may comprise sensors for detecting external guiding means, for example a coloured line or electromagnetic fields. It is advantageous for the transport apparatus to detect external guiding means, so that the transport apparatus can be moved along such external guiding means. Furthermore, the at least one sensor may comprise a sensor for detection RFID tags to detect external guiding positions. The at least one sensor may also comprise a camera, a microphone, and a thermometer. The transport apparatus may also comprise a local position system.

[0072] The transport apparatus may also be provided with an output system for information to an operator. The output system may comprise a screen for information, a speaker, or lights.

[0073] As stated above, the transport apparatus according to the invention comprises a control unit for controlling the steering mechanism and the first and the second motion mechanisms of the transport apparatus.

[0074] In addition to the steering mechanism, the control unit may control the drive motor of the apparatus and thereby the speed and movement direction of transport apparatus. The control unit is configured to control the activation of the first and second motion mechanisms and thereby a position of the lifting plate and the wheel assemblies with respect to the chassis of the transport apparatus. The control unit may receive data from the at least one sensor.

[0075] The transport apparatus may be configured for wireless communication with other transport apparatus according to the invention. The wireless communication is through any known wireless communications protocol.

[0076] The wireless communication may facilitate simultaneous operation of several transport apparatuses. A transport apparatus may be in a master / slave system with another transport apparatus or several transport apparatuses. The transport apparatuses may also be in a master / m aster system.

[0077] The transport apparatus may further be configured for wireless communication with an external control system through any known wireless communications protocol. The external control system may be used to control one or several transport apparatuses. This can facilitate simultaneous operation of several transport apparatuses.

[0078] In a second aspect the invention relates to a transport system comprising at least two

[0079] P31278PC00_Description and claims for PCT transport apparatuses according to the first aspect of the invention. A transport system comprising several transport apparatuses can be used to create an efficient storage system. As explained above, several transport apparatuses in a row, or in several rows, can be used to simultaneously move several loads, typically pallets.

[0080] The transport system according to the second aspect of the invention may comprise an external control system. The external control system can be used to control the transport apparatuses in the transport system, and thus facilitate simultaneous operation of the transport apparatuses. The transport system may be fully automated.

[0081] In a third aspect the invention relates to a method for transporting a load. The method comprises the steps:

[0082] A) providing a transport apparatus according to the first aspect of the invention;

[0083] B)- moving the transport apparatus into a cavity in the load while at least one of the lifting plate and the wheel assemblies is in a lowered or retracted first position, respectively;

[0084] C)- activating at least one of the first motion mechanism and the second motion mechanism to move the lifting plate at least towards the elevated position, to lift the load;

[0085] D)- moving the transport apparatus to a desired position; and

[0086] E)- activating at least the first motion mechanism to lower at the lifting plate to the lowered position to bring the load back onto the plane.

[0087] Depending on which of the first and second motion mechanisms that was / were activated in step C), corresponding motion mechanism(s) may be activated in step E) to lower the lifting plate to the lowered position. If both the first motion mechanism and the second motion mechanism in step C) were activated to bring the lifting plate to its elevated position with respect to the chassis, and the wheel assemblies to their advanced second position, the lifting plate in step C) is in the elevated position with respect to the plane.

[0088] In step B), the wheel assembly may be in the retracted first position.

[0089] In step C), the second motion mechanism may be activated to bring the wheel assemblies to their advanced second position.

[0090] The method according to the third aspect of the invention is an easy and space-saving method for moving and storing a load. After the transport operation is complete, the transport apparatus may be stored underneath the load it has transported so that is does not take up space on for example a storage floor.

[0091] The method may further comprise moving the transport apparatus away from the load.

[0092] P31278PC00_Description and claims for PCT The transport apparatus may be moved to for example a charging station or a specified storage area for the transport apparatus.

[0093] The method may further comprise moving the transport apparatus through a cavity in a load while the lifting plate is in the lowered position. This step may be performed if the load to be transported is stored behind other loads. The load to be transported may easily be reached by a transport apparatus driving beneath the loads stored in front of the load to be transported.

[0094] The method may further comprise providing a transport system according to the second aspect of the invention. The method may comprise utilizing at least one of the at least two transport apparatuses for moving a load away for a desired load to be moved by another of the at least two transport apparatuses.

[0095] Thus, in an embodiment wherein the transport system comprises several transport apparatuses, the method may for example be used to easily access a desired load that is stored behind other loads. Some of the transport apparatuses in the system may be used to move the loads away so that the desired load can easily be accessed.

[0096] Independently of a number of transport apparatuses in a system according to the second aspect of the invention, at least two transport apparatuses may be operated simultaneously. Simultaneous operation of at least two apparatuses wherein at least one is for moving a load away for a desired load to be moved by another of the at least two transport apparatuses, provides an efficient system.

[0097] BRIEF INTRODUCTION OF THE FIGURES

[0098] In the following is described examples of a preferred embodiments of the transport apparatus according to the present invention illustrated in the accompanying drawings, wherein:

[0099] Fig. 1a shows a transport apparatus from above;

[0100] Fig. 1b shows the transport apparatus from Fig. 1a from the side, with the lifting plate in the lowered position and the wheel assemblies in a retracted first position;

[0101] P31278PC00_Description and claims for PCT Fig. 1c shows the transport apparatus from Fig. 1b, with the lifting plate in the elevated position and the wheel assemblies in the advanced second position;

[0102] Fig. 1d shows a cross-section through A-A of the transport apparatus in Fig. 1a;

[0103] Fig. 2a shows a cross section through B2-B2 of the transport apparatus in fig. 1b;

[0104] Fig. 2b shows a cross section through C2-C2 of the transport apparatus in fig. 1C;

[0105] Fig. 2c shows the transport apparatus in fig. 2a, but with the wheels turned 90 degrees;

[0106] Fig. 2d shows the transport apparatus similar to the apparatus shown in fig. 2a, wherein the first motion mechanisms for moving the lifting plate relative to the chassis are independent from the second motion mechanisms for moving the wheel assemblies relative to the chassis;

[0107] Fig. 2e shows a cross-section through D-D of the transport apparatus from Fig. 2c, wherein the wheel assemblies are pivoted with respect to the chassis to the advanced second position and the lifting plate is in the elevated position;

[0108] Fig. 3a shows a further embodiment of the transport apparatus in fig. 1 d, but with the lifting plate in the elevated position and the wheel assemblies in the advanced second position, wherein a biasing means extend from the wheel assembly towards the lifting plate;

[0109] Fig. 3b shows in larger scale details of left portion of the transport apparatus in fig.3a;

[0110] Fig. 4a shows in larger scale a cut through B-B of the transport apparatus in Fig. 1b;

[0111] Fig. 4c shows in larger scale a cut through C-C of the transport apparatus in Fig. 1c;

[0112] Fig. 5a shows in larger scale a cut through B1-B1 of the transport apparatus in Fig. 1b;

[0113] Fig. 5b shows in larger scale a cut through C1-C1 of the transport apparatus in Fig. 1c;

[0114] P31278PC00_Description and claims for PCT Fig. 6a shows an arm forming part of the motion device shown in Figs. 4b and 5b;

[0115] Fig. 6b shows an alternative embodiment of the arm in fig. 6a; and

[0116] Figs. 7a-7c show a process of transporting three loads simultaneously by a transport system according to the invention.

[0117] Any positional indications refer to the position shown in the figures.

[0118] In the figures, same or corresponding elements are indicated by same reference numerals. For clarity reasons, some elements may in some of the figures be without reference numerals.

[0119] A person skilled in the art will understand that the figures are just principal drawings. The relative proportions of individual elements may also be distorted.

[0120] In the figures, reference number 1 denotes a transport apparatus for a load. The transport apparatus comprises a chassis 12, at least one lifting plate 15 having a top face for abutting against a load, and at least two wheel assemblies 30 arranged at a mutual distance along a length of the chassis 12. In the embodiments shown, each of the two wheel assemblies 30 is operatively connected to a drive motor 31. However, in an alternative embodiment, only one of the wheel assemblies 30 is operatively connected to a drive motor 31.

[0121] The wheel assemblies 30 comprises a steering mechanism for allowing steering of the transport apparatus 1. In one embodiment (not shown) only one of the wheel assemblies is provided with a steering assembly.

[0122] The chassis 12 comprises a first motion mechanism 20 operatively connected to the lifting plate 15. The first motion mechanism is configured for moving the lifting plate 15 relative to the chassis 12 between a lowered position as shown for example in figures 1b and 1 d, and an elevated position as shown for example in fig. 1c.

[0123] The chassis 12 further comprises a second motion mechanism 20’ operatively connected to the wheel assemblies 30. The second motion mechanism 20’ is configured for moving the at least two wheel assemblies 30 relative to the chassis 12 between a retracted first position and an advanced second position.

[0124] The chassis 12 also comprises a control unit for controlling the drive motor 31 and the

[0125] P31278PC00_Description and claims for PCT motion mechanism 20, 20’.

[0126] The transport apparatus 1 is configured to be movable into and through a cavity in the load when at least one of the lifting plate 15 and the wheel assembly 30 is in the lowered position.

[0127] Each wheel assembly 30 comprises a pair of parallel wheels 32. In the embodiment shown, each wheel 32 in the pairs of wheels 32 is operatively connected to a respective drive motor 31. In the embodiment shown in the figures, each pair of wheels 32 is pivotably connected to the chassis 12 for allowing turning of the wheels 32 with respect to an axis being perpendicular to the shafts of the wheels 32, thereby allowing steering of the transport apparatus 1.

[0128] The transport apparatus 1 is shown from above in Fig. 1a. The length of the transport apparatus 1 is in this example larger than the width of the transport apparatus 1 , a shape suitable for fitting into one of the cavities of a load such as a Euro-pallet or any other load comprising an oblong cavity. When the lifting plate 15 is in the lowered position, and the wheel assemblies 30 are in the retracted first position as shown in Fig. 1b, the height of the transport apparatus 1 is at a minimum and the transport apparatus 1 can pass into a cavity in for example a Euro-pallet.

[0129] In one embodiment, the first motion mechanism 20 for moving the lifting plate 15 and the second motion mechanism 20’ for moving the wheel assemblies 30 are configured for being controlled independently of each other. For some pallets, the transport apparatus 1 can pass into a cavity thereof even if either the wheel assemblies 30 are in the advanced second position, or the lifting plate 15 is in the elevated position.

[0130] In Fig. 1c, the lifting plate 15 has been moved to the elevated position, and the wheel assemblies 30 have been moved to the advanced second position wherein the chassis 12 has a greater clearance from a plane supporting the apparatus 1 than that shown in Fig. 1b.

[0131] In a prototype of the transport apparatus 1 adapted for handling Euro-pallets, the lifting plate 15 may be elevated by approximately 2 cm with respect to its lowered position. In the prototype, a clearance between the plane is increased by approximately 2 cm when the wheel assemblies 30 are in the advanced second position as compared with the wheel assemblies 30 are in their retracted first position. The lifting plate 15 can therefore lift the Euro-pallet from the plane. Depending on the configuration of the motion mechanisms 20,

[0132] P31278PC00_Description and claims for PCT 20’, a difference between a lowest position and a highest position of the lifting plate 15 may be more than 4 cm (2 + 2 cm) as in the prototype, or less than 4 cm as in the prototype.

[0133] The prototype of the transport apparatus 1 as shown in the figures is configured to lift a load of up to one tonne. Two such prototypes may together lift a load of up to two tonnes. Other examples of the transport apparatus according to the invention may lift a load of more than one tonne.

[0134] In the example shown in for example Figs. 1a - 1c, the lifting plate 15 covers a top side 121 of the chassis 12, and encloses a portion of the chassis 12, especially when the lifting plate 15 is in the lower position.

[0135] The steering mechanism of the transport apparatus 1 is shown in Fig. 2c and Fig. 2d. The steering mechanism comprises two pair of wheels 32 at a mutual distance along the length of the chassis 12. Each wheel 32 in the pairs is connected to a drive motor 31 through a respective drive chain or gear 33. The drive motor 31 (best seen in fig. 4a) is configured for rotating the respective wheel 32 in two directions, i.e. , both in a clockwise and an anticlockwise direction. The two wheels 32 in the pairs are rotatably connected to a shaft 35. The wheels 32 in a pair can be seen in Fig. 4a and 4b.

[0136] By rotating one of the wheels 32 in the pair in one direction, and the other wheel 32 in the pair the other direction, the pair of wheels 32 can be turned or pivoted 90 degrees, as shown in Fig. 2c. The transport apparatus 1 can in this way be moved and rotated in any x- or y-direction relative to the two-dimensional plane supporting the transport apparatus 1. Thus, the transport apparatus 1 is movable in a direction parallel to the length of the transport apparatus 1 (in an x-direction in Fig. 2a), and in a direction perpendicular to the length of the transport apparatus 1 (in a y-direction in Fig. 2c), and in any direction therebetween.

[0137] In another example (not shown) of the transport apparatus 1 , the steering mechanism comprises two single wheels at a mutual distance along the length of the chassis 12. The wheels are connected to a respective drive motor 31 , for rotating the wheels, and to a shaft connected to a second motor for adjusting the direction of the wheels.

[0138] In yet another example (not shown) of the transport apparatus 1 , the steering mechanism comprises two wheel assemblies, wherein each wheel assembly comprises two wheels. The two wheels in the wheel assemblies are rotatable in different directions, the directions

[0139] P31278PC00_Description and claims for PCT being perpendicular to each other. One of the wheels may rotate in a direction parallel to the length of the transport apparatus 1 , and the other in a direction parallel to the width of the transport apparatus 1 . The two wheels in the wheel assemblies are liftable and lowerable independently of each other. The direction of the movement of the transport apparatus 1 depends on which wheel in the wheel assemblies are in contact with the plane. The wheels in the wheel assemblies may also comprise a pair of mutually spaced, parallel wheels.

[0140] As best seen in figures 2a-2e, each wheel assembly 30 of the transport apparatus 1 comprises two sets of motion mechanisms arranged at a mutual distance along the length of the chassis 12. Each set of motion mechanism comprises a first motion mechanisms 20 for moving the lifting plate 15 between the lowered position as shown for example in figures 1b and 1d, and the elevated position as shown for example in figures 1c and 4b. Each set of motion mechanism further comprises a second motion mechanism 20’ operatively connected to the wheel assembly 30. The second motion mechanism 20’ is configured for moving the wheel assembly 30 between the retracted first position and the advanced second position. The retraced first position is shown for example in figures 1b and 1d, while the advanced second position is shown for example in figures 1c and 4b. Each one of the first motion mechanism 20 and the second motion mechanism 20’comprises a screw 22, which is operatively connected to a motion motor 21 configured for rotating the screw 22. The screws 22 are rotatably connected to a portion of the chassis 12.

[0141] A pair of sliding members 24 is in threaded engagement with each screw 22 so that the sliding members 24 is moved radially with respect to the length of the transport apparatus 1 when the screws 22 are rotated.

[0142] As best seen in figures 2a, 2b, 4b and 5b, each sliding member 24 is operatively connected to a first end portion of a first arm 23a and a first end portion of a second arm 23b by means of a pivot connection.

[0143] A second end portion of each of the first arms 23a is pivotably connected to a portion of the lifting plate 15 such that the lifting plate 15 is elevated with respect to the chassis 12 when the screws 22 are rotated such that the sliding members 24 are moved towards a center of the chassis 12. When the sliding members 24 are moved towards side portion of the chassis 12, the lifting plate 15 is moved towards the lowered position.

[0144] A second end portion of each of the second arms 23b is pivotably connected to a portion of the wheel assemblies 30 such that the wheel assemblies 30 are moved from their re-

[0145] P31278PC00_Description and claims for PCT tracted first position towards their advanced second position when the screws 22 are rotated such that the sliding members 24 are moved towards a center of the chassis 12. When the sliding members 24 are moved towards side portion of the chassis 12, the wheel assemblies 30 are moved towards the retraced first position.

[0146] Thus, when the sliding members 24 are approximately at the end of the screw 22, as shown in Fig. 5a, an angle between a longitudinal axis of the arms 23a and a top surface of the lifting plate 15 is at a minimum, and the lifting plate 15 is in the lowered position. As the screw 22 rotates, each pair of sliding members 24 is moved towards a center portion of the chassis 12, as shown in figures 4b and 5b. The angle between the longitudinal axis of the arms 23a and the top surface of the lifting plate 15 is now close to 90 degrees, and the lifting plate 15 is moved in its elevated position. To move the lifting plate 15 back to the lowered position, the screw 22 is rotated in the opposite direction, moving the sliding member 24 towards the side portions of the chassis.

[0147] Similarly, as the screws 22 rotates and each pair of sliding members 24 is moved towards a center portion of the chassis 12, an angle between the longitudinal axis of the arms 23b and the wheel assemblies 30 is close to 90 degrees, and the wheel assemblies 30 are now in their advanced second position. When the wheel assemblies 30 are in advanced second position, the chassis 12 itself is also in an elevated position with respect to a plane supporting the transport apparatus 1. To move the wheel assemblies 30 back to the retraced first position, the screw 22 is rotated in the opposite direction, moving the sliding member 24 towards the side portions of the chassis 12.

[0148] In the embodiment shown in figures in 2a, 2b, 4b and 5b, and discussed above, the first arms 23a and the second arms 23b operatively connected to each pair of sliding elements 24, operates in tandem. This means that a screw 22 and the appurtenant pair of sliding members 24 may activate the lifting plate 15 together with moving the wheel assembly 30 with respect to the chassis 12.

[0149] The transport apparatus 1 illustrated in figures 4b and 5b is provided with first arms 23a and second arms 23b of a type shown in Fig. 6a. In Fig. 6a, the arm 23a, 23b is provided with circular apertures 23’ configured for forming part of a pivot connection. This means that a screw 22 and the appurtenant pair of sliding members 24 activate the lifting plate 15 simultaneously with moving the wheel assembly 30 with respect to the chassis 12. However, by providing either the first arms 23a or the second arms 23b with at least one oblong aperture 23” as shown to the left in Fig. 6b, a delayed activation of either the lifting

[0150] P31278PC00_Description and claims for PCT plate 15 or the wheel assembly 30 is achieved while the sliding elements 24 are moved with respect to the screw 22. Thus, a movement distance of the lifting plate 15 with respect to the chassis 12 may be different from a movement distance of the wheel assemblies 30 with respect to the chassis 12.

[0151] Figures 2d and 2e illustrates an embodiment of the transport apparatus 1 wherein the first motion mechanism 20 configured for moving the lifting plate 15 relative to the chassis 12 is operated independently of the second motion mechanism 20’ configured for moving the wheel assemblies 30 relative to the chassis 12. As illustrated in fig. 2e, each of the two wheel assemblies 30 has a first portion pivotably connected to the chassis 12 via a pivot connection 25, while a second portion opposite the first portion is operatively connected to the second motion device 20’. By controlling the appurtenant motion motors 21 individually or in pairs of the first and second motion devices 20, 20’, the wheel assemblies 30 can be moved to and from their advanced position independently of moving the lifting plate 15 to and from its elevated position.

[0152] Turning now to figures 3a-3b illustrating a further embodiment of the transport apparatus 1 illustrated in fig. 1d. In fig. 3a the lifting plate 15 is shown in its elevated position and the wheel assemblies 30 are in the advanced second position. In the embodiment shown, the transport apparatus 1 comprises a biasing means 38 arranged in connection with each wheel assembly 30. The biasing means is in the form of springs 38 (two shown at each wheel assembly) having a first end portion supported by a portion of the wheel assembly 30, and a second portion facing an inner portion of the lifting plate 15. The number of springs may be more than the two shown, for example four or six. The spring force depends on the relative position between the lifting plate 15 and the wheel assembly 30 and is at a maximum when the lifting plate 15 is in its lowered position and the wheel assembly 30 is in its retracted first position. In this position, the angle between the longitudinal axis of the first arms 23a and the top surface of the lifting plate 15, and the angle between a longitudinal axis of the second arms 23b and the wheel assembly 30, are at a minimum. Therefore, the springs 38 facilitate movement of the lifting plate 15 from its lowered position, and movement of the wheel assembly 30 from its retraced first position. Thus, a start force needed from the motion motors 21 are reduced.

[0153] As best seen in Fig. 3b showing in larger scale left portion of the apparatus in Fig. 3a, a top portion of the springs 38 is at not in contact with the inside of the lifting plate 15 when a mutual distance between the lifting plate 15 and the wheel assembly is at a maximum. In such a position, the extra force provided by the springs 38 are not needed since the

[0154] P31278PC00_Description and claims for PCT angle between the longitudinal axis of the arms 23a, 23b, and the lifting plate 15 and the wheel assembly 30, respectively is close to 90 degrees.

[0155] In figures 3a-3b, the wheel assembly 30 is further provided with a cleaning device 50 configured for removing at least some loose debris that may be on a plane in front of the set of wheels 30. The cleaning device 50 extends downwardly from an end portion of the wheel assembly 30 facing end portions of the transport apparatus 1, such that at least some of any loose debris laying on a plane in front of the leading wheels 32 in a direction of movement of the apparatus 1 , are removed. The cleaning device 50 may for example be broom or brush, a plough or scraper, or a combination thereof. A brush may be stationary, or the brush may be a rotating brush operatively connected to a motor (not shown) for rotating the brush in a direction being opposite of a rotating direction of the wheels 32. A rotating direction of the motor is controlled by the control unit of the transport apparatus 1 such the rotation direction of the brush depends on a direction of movement of the transport apparatus 1.

[0156] The right portion of the transport apparatus 1 is in the embodiment shown in Fig. 3a identical to the left portion and therefore not discussed further. In another example (not shown) of the transport apparatus 1 , biasing means such as springs are extending between a portion of the chassis 12 and the lifting plate 15. For example four springs, one inside each corner of the chassis 12 of the transport apparatus 1. The force needed for moving the lifting plate 15 to the elevated position is highest when the angle between the longitudinal axis of the first arms 23a and the top surface of the lifting plate 15 is at a minimum. The springs facilitate the lifting of the lifting plate at the start of the movement from the lowered position to the elevated position.

[0157] The transport apparatus 1 can be driven in any direction in the xy-plane (Fig. 2c) and lift a load on the lifting plate 15 in the z-direction (Fig. 1d).

[0158] The transport apparatus 1 shown in the figures is configured for remote operation. The chassis 12 comprises a control unit (not shown). The control unit comprises a transceiver (not shown) configured for wireless communication with other transport apparatuses 1 or an external control system (not shown). The chassis 12 comprises further a motor drive unit 44 which controls the movement of the transport apparatus 1 in the x- and y- direction. The movement of the lifting plate 15 and the wheel assemblies 30 in the z-direction is controlled by a relay (not shown). Furthermore, the chassis 12 comprises batteries 44 for the drive motor 31 , the motion motors 21 of the motion mechanisms 20, 20’ and the con-

[0159] P31278PC00_Description and claims for PCT trol unit. The chassis 12 also comprises an electronic unit (not shown) for distribution of power from the batteries 44. The electronic unit is also used when the transport apparatus 1 is connected to a power supply (not shown) for charging.

[0160] Figs. 7a to 7c show a storage system comprising sixteen loads 100 stored in a compact manner. The loads 100 are stored in rows rA to rD and columns cA to cD. A load 100a is stored in the middle of the storage system in row rC and column cB and is strenuous to get out using conventional load carriers. Figs. 7a to 7c illustrates how a transport system comprising three transport apparatuses 1-1 , 1-2, and 1-3 can be used to easily reach the desired load 100a. In Fig. 7a each transport apparatus 1-1 , 1-2, and 1-3 is aligned with a row of loads 100, rA, rB, and rC, respectively. The lifting plates 15 of the transport apparatuses 1-1, 1-2, and 1-3 are in the lowered position (see Fig. 4a), and / or the wheel assemblies 30 are in the retracted first position, so that the transport apparatuses 1-1 , 1-2, and 1-3 can be driven underneath the loads 100 in columns cC and cD to reach the column cB where the desired load 100a is stored. When the transport apparatuses 1-1 , 1-2, and 1-3 are underneath the loads 100 in the column cB, see Fig. 7b, the three transport apparatuses 1-1, 1-2, and 1-3 can each lift its respective load 100 and simultaneously transport it out of the storage system following the arrow shown in Fig. 7b. Fig. 7c shows the transport apparatus 1-3 driving the desired load 100a out from the storage system, following one of the arrows in Fig. 7c.

[0161] Simultaneous operation of the three transport apparatuses 1-1 , 1-2, and 1-3, provides an efficient system wherein several loads can be stored in a space saving manner on a plane.

[0162] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise", and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0163] P31278PC00_Description and claims for PCT

Claims

1. C l a i m s1 . A transport apparatus (1) for a load, comprising:- a chassis (12) having a length and a width;- at least one lifting plate (15) having a top face for abutting against a load; and- at least two wheel assemblies (30) at a mutual distance along the length of the chassis (12), wherein at least one of the at least two wheel assemblies (30) is operatively connected to a drive motor (31), and at least one of the wheel assemblies comprising a steering mechanism for allowing steering of the transport apparatus (1); wherein the chassis (12) comprises: a motor operated first motion mechanism (20) operatively connected to the lifting plate (15), and configured for moving the lifting plate (15) relative to the chassis (12) between a lowered position and an elevated position, characterized in that the chassis (12) further comprises a motor operated second motion mechanism (20’) operatively connected to the wheel assemblies (30), and configured for moving the at least two wheel assemblies (30) relative to the chassis (12) between a retracted first position, and an advanced second position wherein, as compared with the retracted first position, a clearance between a lowermost portion of the chassis and a plane that in a position of use supports the transport apparatus (1), is increased; and a control unit for controlling the drive motor (31) and the motion mechanism (20, 20’), wherein the transport apparatus (1) is configured to be movable into and through a cavity in the load when at least one of: the lifting plate (15) is in the lowered position; and the wheel assemblies (30) are in the retracted first position.

2. The transport apparatus (1) according to claim 1 , wherein the first motion mechanism (20) is configured for moving the lifting plate (15) relative to the chassis (12) simultaneously with the second motion mechanism (20’) moving the at least two wheel assemblies (30) relative to the chassis (12).

3. The transport apparatus (1) according to claim 1 , wherein the second motion mechanism (20’) is configured for activating movement of the wheel assemblies (30) towards the advanced second position before the lifting plate (15) is activated towards the elevated position by means of the first motion mechanism (20).P31278PC00_Description and claims for PCT4. The transport apparatus (1) according to claim 1 , wherein the first motion mechanism (20) is configured for activating the lifting plate (15) towards the elevated position before the wheel assemblies (30) are activated towards the advanced second position by means of the second motion mechanism (20’).

5. The transport apparatus according to claim 3 or 4, wherein the order of activation of the lifting plate (15) and the wheel assemblies (30) is mechanically controlled.

6. The transport apparatus (1) according to claim 1 , wherein the first motion mechanism is configured for being operated independently of the second motion mechanism.

7. The transport apparatus (1) according to any one of the preceding claims, wherein the lifting plate (15) covers a top side (121) of the chassis (12) and encloses a portion of the chassis (12).

8. The transport apparatus (1) according to any one of the preceding claims, further comprising a cleaning device configured for removing loose particles being on a base in front of the wheel assemblies (30).

9. The transport apparatus (1) according to claim 8, wherein the cleaning device comprises at least one of a broom and a plough.

10. A transport system comprising at least two transport apparatuses (1) according to any one of the preceding claims.11 . The transport system according to claim 10 further comprising an external control system.

12. A method for transporting a load, characterized in that the method comprising the steps:A) providing a transport apparatus (1) according to any one of claims 1 to 9;B)- moving the transport apparatus (1) into a cavity in the load while at least one of the lifting plate (15) and the wheel assemblies (30) is in a lowered or retracted first position, respectively;C)- activating at least one of the first motion mechanism (20) and the second motion mechanism (20’) to move the lifting plate (15) at least towards the elevated position, to lift the load;P31278PC00_Description and claims for PCTD)- moving the transport apparatus (1) to a desired position; andE)- lower the lifting plate (15) to bring the load back onto the plane.

13. The method according to claim 12, further comprising providing a transport system according to claim 10 or 11 , wherein at least one of the at least two transport apparatuses is utilized for moving a load away for a desired load to be moved by another of the at least two transport apparatuses.

14. The method according to claim 13, wherein the at least two transport apparatuses are operated simultaneously.P31278PC00_Description and claims for PCT

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