WO2012096570A1

WO2012096570A1 - Vehicle particularly transfer device

Info

Publication number: WO2012096570A1
Application number: PCT/NL2012/000006
Authority: WO
Inventors: Robbert Paul VAN DER HEUL
Original assignee: VAN DROGENBROEK, Jan-Hein
Priority date: 2011-01-13
Filing date: 2012-01-13
Publication date: 2012-07-19
Also published as: NL1039295C2; NL1039295A

Abstract

Mobile vehicle, particularly transfer device for a load, such as a person or an object, comprising a frame with an operation or front side and a rear side, a base situated at the rear side and at least one leg connected to the base and extending therefrom usually to the front side, preferably in horizontal direction, preferably two such legs, wherein the frame is provided with a load bearer, wherein at least one leg, viewed along the leg, at a location spaced apart from the base is provided with a drive wheel, wherein the drive wheel comprises a first drive, such as a motor, which in vertical sense is substantially below, preferably entirely below the upper side of the running surface of the first drive wheel in operational position, wherein a first direction control for the first drive wheel for steering the orientation of the first drive wheel with respect to the leg is at least partially, preferably substantially, arranged on the leg.

Description

Vehicle particularly transfer device

BACKGROUND OF THE INVENTION

The invention relates to a mobile vehicle, particularly transfer device. The vehicle can be a service or work trolley that move themselves or a mobile transfer device, such as a forklift, goods platform carriage, hoist, transfer lift (for patients), for objects or persons that may or may not be mobile.

It may particularly regard the moving of persons, such as patients, in upright, sitting, supine or suspended condition, in for instance an intramural or extramural environment such as for instance a hospital or a home. These might include among others a hospital bed, a transfer lift for patients, an operating table or a rehabilitation means. It may furthermore include the moving of goods in a logistic process or during assembly, a goods platform carriage for distribution, a forklift or portable forklift for moving for instance pallets. It may also include an aid for an assembly process such as for instance a mobile motorised hoist. By way of example a number of transfer lifts for patients known from patent specifications are mentioned below, in which each time there is question of a base situated at the rear, a load bearer extending forward from the base and two legs extending forward from the base. In US 5.758.371 such a transfer device is shown wherein the base is provided with two controllable drive wheels and between them a differential and rigid casters at the front ends of the legs. GB 2.337.030 shows such a transfer device wherein the base is provided with two castors and the legs are each provided with a drive comprising a wheel driven by a motor and a wheel that is driven via a right-angled transmission by said drive wheel. By means of a lift mechanism in the leg either the one drive wheel or the other drive wheel can be brought into contact with the basis.

In US 6.092.247 such a transfer device is shown, wherein the base is provided with two castors and the legs are provided with drive wheels at their front ends with behind them drive engines for them attached to the leg. The legs can be swung in the horizontal plane, after at the leg ends a small rigid caster has been lowered to lift the drive wheel from the ground.

US 2006/0137091 shows such a transfer device, wherein the base is provided with two drive wheels that can be steered synchronously and the legs at their front ends are provided with castors. The legs can be swung in the horizontal plane.

EP 1.595.519 and WO 2009/136359 show such transfer devices with castors at the leg ends and a centrally, liftable drive wheel under the base.

EP 2.208.487 shows such a transfer device wherein legs that can be swung in the horizontal plane at their front ends are provided with castors and the base is provided with two steerable drive wheels of which the points of rotation are situated at a different distance from the rear. A drawback of this existing system is that still only a limited directional freedom is created and there is a delay in switching to either steering directions.

In general the manoeuvrability and deployability of said known transfer devices can be subject of improvement. In most known transfer lifts the drive wheel is placed relatively far from the load point, which has an adverse effect on the stability and/or the drive. As a result the device itself has to be designed heavy in order to gain sufficient traction on said driven wheels. SUMMARY OF THE INVENTION

It is an object of the invention to provide a vehicle of the type mentioned in the preamble with which during use a reliable drive can be realised.

It is an object of the invention to provide a vehicle of the type mentioned in the preamble with which during use sufficient stability can be realised. It is an object of the invention to provide a vehicle of the type mentioned in the preamble with which safe and reliable transport of a load, person or object can be realised.

It is an object of the invention to provide a vehicle of the type mentioned in the preamble with which manoeuvring can take place in an easy and/or reliable manner.

It is an object of the invention to provide a vehicle of the type mentioned in the preamble with which accurate positioning is possible during loading and unloading.

It is an object of the invention to provide a vehicle of the type mentioned in the preamble with which within a small floor space an as large as possible manoeuvrability is possible. According to one aspect the invention for that purpose provides a vehicle as described in one or more of the attached claims.

According to one aspect the invention provides a mobile vehicle, particularly transfer device for a load, such as a person or an object, comprising a frame with an operation or front side and a rear side, a base situated at the rear side and at least one leg connected to the base and extending therefrom, usually to the front side, preferably in horizontal direction, preferably two such legs, wherein the frame is provided with a load bearer, wherein at least one leg, viewed along the leg, at a location spaced apart from the base is provided with a first drive wheel, wherein the drive wheel comprises a first drive, such as a motor, which preferably in vertical sense is substantially below, preferably entirely below the upper side of the running surface of the first drive wheel in operational position, wherein a first direction control for the first drive wheel for steering the orientation of the first drive wheel with respect to the leg is at least partially, preferably substantially, arranged on the leg. In that way the leg in question and the base of the frame are highly controllable as regards orientation. Manoeuvring is thus made easier, particularly if the vehicle is used for moving a load that is taken over from a load bearer or surface having little/limited underpass room, such as a hospital bed in case of a transfer lift for patients or a transport trailer or loading floor of a van from which goods have to be lifted. The steerable drive in the leg can with little effort be positioned underneath the load to be moved with accuracy and at a position that is advantageous as regards stability and distribution of weight. It is noted that by "first drive" both the drive source, motor, and the transmission between drive source and drive wheel is meant. The first direction control may comprise a first steering drive for adjusting the orientation of the first drive wheel, wherein in vertical sense the first steering drive is substantially below, preferably entirely below the upper side of the running surface of the first drive wheel in operational position. In that way the usability when moving persons or objects that have to be taken over from or be transferred to supports with limited underpass room, such as hospital beds, is further increased. The vehicle according to the invention thus forms an advantageous means of transport for institutions in health care. It is noted that by "first steering drive" both the drive source, motor, and the transmission between drive source and drive wheel is meant.

In one embodiment the first direction control comprises a first steering drive for adjusting the orientation of the first drive wheel, wherein the first steering drive comprises a motor that is placed stationary with respect to the drive wheel. In one embodiment with low construction height the first steering drive intersects the plane in which the horizontal central axis of rotation of the drive wheel is situated. In a compact embodiment the first steering drive comprises a wheel holder having a first holder member that is attached to the first leg and a second holder member which with respect to the first holder member is rotatable about a substantially vertical central axis, particularly a purely vertical central axis, wherein the second holder member engages onto the first drive wheel, particularly a physical wheel axis (hollow or solid) thereof, preferably on both sides of the drive wheel, for conjoined rotation about the substantially vertical central axis. The second holder member can be annular or comprise one or more ring segment- shaped parts that are movable as one unity with each other, which are rotatably guided about the said vertical central axis by the first holder member. The first holder member can then comprise a hollow casing, particularly having a circular cross-section, and surround the second holder member therewith, as a result of which it is also shielded. The first drive can advantageously and in a compact manner, be placed with the wheel inside the first holder member and within it rotatably about the vertical central axis, particularly placed inside a turning ring that is formed by the first and second holder member.

In a compact embodiment the first and second holder members cooperate in the form of an electromotor, wherein on the one holder member, preferably the first holder member, a ring of electromagnets is attached and on the other holder member, preferably the second holder member, a ring of permanent magnets is attached.

The manoeuvrability of the vehicle, including optional load to be moved, is increased if the first direction control has a range of at least 90 degrees, preferably over 90 degrees, preferably 180 degrees or more, preferably a range of 360 degrees or more.

The first direction control may comprise means for detecting the orientation of the first drive wheel with respect to the leg or with respect to the base.

In a compact embodiment the first drive for the first drive wheel is arranged for conjoined steer rotation with the fist drive wheel by the first direction control. In a compact embodiment the first drive comprises a motor having a drive central axis that is substantially parallel to the central axis of rotation of the first drive wheel, particularly coincides therewith. The first drive preferably comprises a hub motor. In a versatile embodiment the upper side of the running surface of the first drive wheel defines the highest point of the leg in question, at least the part of the leg in question which is situated near the first drive wheel and further towards the front side. In that way the deployability of the vehicle according to the invention is further increased. Manoeuvrability is enhanced if the leg is provided with the first drive wheel at a location close to its outer end.

In a first further development of the vehicle according to the invention, with two of said legs, both legs are provided with the first drive wheel and a second drive wheel, respectively, preferably at a location close to the outer end of the leg in question. The first and the second drive wheels with their first and second drive, respectively, preferably are designed so as to be mutually similar.

Just like the first drive the second drive wheel can be provided with a second direction control, which preferably is designed in accordance with the first direction ■^■·, control, wherein the vehicle preferably is provided with a central control unit for controlling the first and second direction control in a mutually adjusted and selective manner. Both direction controls may for instance be simultaneously controlled or one after the other, whatever is desired. Control and manoeuvrability of the vehicle is thus enhanced to a large extent.

In a first further development of the vehicle according to the invention at least one leg, preferably both legs, is/are connected to the base so as to be movable, particularly adjustable, in a horizontal plane.

In one embodiment the leg/legs is/are connected to the base so as to be rotatable in a horizontal plane. Alternatively or additionally at least one leg, preferably both legs, is/are connected to the base so as to be linearly moveable in a horizontal plane, preferably in a direction transverse to the leg in question.

In that case the first/second direction control permits an orientation of the drive wheel in question with which the desired movement of the leg with respect to the base is made possible, particularly an orientation transverse to the leg. The leg is then as it were moved with respect to the base by the drive wheel in question. In one embodiment the direction control comprises means for steering the orientation of the drive wheel with respect to the leg while preserving the direction of said drive wheel with respect to the world. In one embodiment the direction control comprises means for steering the orientation of the drive wheel with respect to the world.

In a compact embodiment the vertical central axis of rotation (the central axis about which the drive wheel is controlled) of the steering drive in question intersects the running surface of the drive wheel in question.

The vertical central axis of rotation of the steering drive in question can intersect the horizontal central axis of rotation of the drive wheel in question. The manoeuvrability of the vehicle is further increased if the base is provided with at least one further drive. Just the said first drive in the first leg considerably enhances the controllability/adjustability of the position and even more so if there is question of said first and second drives. In both arrangements the controllability/adjustability of the position is even further enhanced by the at least one further drive at the base. In the latter case the first and second and further drive wheels may form a polygon of drive points. The manoeuvrability is further enhanced if the vehicle is provided with a further direction control for the further drive wheel for steering the orientation of the further drive wheel in question with respect to the base.

The resultant force of the load-engaging device of the load bearer that engages the load, which resultant in horizontal direction, in the direction towards the front side of the frame, is spaced apart from the base, can then, considered in projection on a horizontal plane, be situated within the polygon, particularly at least near the centre of the described circle of said polygon. In that way the joint weight of vehicle and load can be advantageously distributed over the drive wheels such that for each drive wheel sufficient grip/traction can be obtained on the floor surface for accurate movement and control wherein large stability of the load is guaranteed. In a simple embodiment there is one further drive wheel at the location of the base, so that there is question of a triangle of -independently controllable- drive points. In general the load bearer may be provided with a load-engaging device that engages the load with a resultant force which in horizontal direction, in the direction towards the front side of the frame, is spaced apart from the base. The load-engaging device may, considered in projection on a horizontal plane be active between the legs, wherein preferably both legs are provided with a drive wheel in question at a location spaced apart from the base.

In a second further development the leg forms a platform with a support surface for a load to be moved. The platform forms a load-engaging device that engages the load so as to support it. In that case the leg may be provided with both the first drive wheel and a second drive wheel, preferably at a location close to the outer end of the leg, wherein, preferably, the first and the second drive wheels with their first and second drive, respectively, are designed so as to be mutually similar. In that case the second drive wheel can be provided with a second direction control, which preferably is designed in accordance with the first direction control, wherein the vehicle preferably is provided with a central control unit for controlling the first and second direction control in a mutually adjusted and selective manner. In one embodiment the first and/or second drive wheel is adjustable in position along the leg in question. In that way the location of the vertical resultant force can be set almost optimally, and the manoeuvring behaviour can be influenced as well.

In a further development the leg provided with the drive wheel is provided with an additional castor, preferably on the distal side of the drive wheel.

In addition thereto the leg in question can be provided with a lifting means for moving the drive wheel between an operational position in contact with a basis and a free position at a distance therefrom. This may be advantageous for at manual force moving the vehicle and positioning the vehicle (particularly not loaded), wherein the steerable drive wheel preferably is not brought into contact with the basis, as well as -under conditions- in case of linearly or rotatably moving and adjusting the said legs. In case of several controllable drives in the leg or in the legs it is therefore possible here to set a desired drive configuration (a la carte), such as with steerable drive in two legs, a steerable drive in one leg, whether or not in combination with a steerable drive in the base. The steering and drive behaviour can as a result be favourably defined depending on the circumstances (vehicle that in part can be swung freely, in part can be steered in a driven manner). In order to bring the vehicle underneath an object with low structural members it can be advantageous that the upper side of the drive wheel in the free position remains within the transverse profile of the leg in question, preferably is situated at a distance of approximately 30 cm or less, preferably 15 cm or less above the basis.

The general manoeuvrability of the vehicle is further enhanced if the frame is supported also by means of one or more castors, wherein preferably on the rear side, on both sides of the base, castors are present. Thus the invention among others provides, contrary to the patent specifications mentioned above, that the vehicle has steering elements and/or displacement elements that are arranged on a location on the vehicle that are situated considerably more advantageous as regards their functionality with respect to the resulting centre of gravity of the load and mass of the means of transport.

The vehicle according to the invention offers the opportunity to be moved in all directions of the compass and to follow any steering curve.

According to a further aspect the invention provides a mobile vehicle, particularly a vehicle according to any one of the attached claims 1-38, provided with a double drive wheel having a primary drive wheel and a secondary drive wheel, of which the horizontal central axes are perpendicular to each other, wherein the primary and the secondary drive wheel are provided with a lifting means for selectively moving the primary drive wheel between an operational position in contact with a basis and a free position at a distance therefrom and simultaneously the secondary drive wheel in opposite sense, and vice versa. In that way the vehicle can at choice be driven in the one direction or a direction perpendicular thereto. In case of the vehicle according to the invention discussed above with a steerable drive in a leg, the double drive wheel is arranged in the second leg and thus constitutes an improving addition as regards manoeuvrability. Alternatively there may be question of a double drive wheel in one single leg or in two parallel legs with a steerable drive in the base.

In a compact embodiment the primary and the secondary drive wheel are supported in an auxiliary frame, that is attached in the frame so as to be tiltable between a position in which the primary drive wheel is in the operational position and a position in which the secondary drive wheel is in the operational position, wherein, preferably, the auxiliary frame can be placed in an intermediate position in which both drive wheels are free.

The primary and secondary drive wheels preferably are each provided with their own motor, so that the one drive wheel is driven by the one motor and the other drive wheel is driven by the other motor that preferably is identical to the one motor.

As stated before the vehicle according to the invention may be particularly suitable as a so-called transfer lift for patients from and to a hospital bed.

According to a further aspect the invention provides a mobile vehicle, particularly transfer device for a person, comprising a frame having a base and two legs protruding therefrom, wherein the legs between them form a space, such as a dock or bay, for offering room to the load, wherein at least one of the legs at a location at a distance from the base is provided with a drive wheel and with means for with respect to the leg steering the drive wheel, particularly drive wheel with its drive.

According to a further aspect the invention provides a mobile vehicle, particularly transfer device for an object, such as a forklift, comprising a frame having a base and two legs protruding therefrom, wherein the legs between them form a space, such as a dock or bay, for offering room to the load, wherein at least one of the legs at a location at a distance from the base is provided with a drive wheel and with means for with respect to the leg steering the drive wheel, particularly drive wheel with its drive, wherein the drive wheel can be steered over an angular range of at least 90 degrees, preferably over 90 degrees, preferably over 180 degrees, preferably an angular range of 360 degrees or more. In a further development of the vehicle according to the invention the load bearer bears suspended therefrom a load-engaging device, such as a hook. The load- engaging device may be designed to be a suspension device for a person, particularly to be used as transfer lift. Alternatively the load-engaging device can be designed to be a suspension device for an object, particularly to be used as a hoist.

In a further development the load-engaging device forms a load support surface on the load bearer. The load-engaging device can then be designed to be a forklift for lifting pallets or other objects.

The invention furthermore relates to a wheel steering and a drive system with a drive wheel. It is an object of the invention to provide a wheel steering with a driven or idling wheel that is compact in horizontal direction.

It is an object of the invention to provide a wheel steering with a driven or idling wheel that has a relatively limited height.

It is an object of the invention to provide a mobile object with one or more of such wheel controls with driven or idling wheel.

According to one aspect the invention for that purpose provides a drive system as described in one or more of the attached claims.

According to one aspect the invention for that purpose provides a wheel system as described in one or more of the attached claims. According to one aspect the invention provides a drive system having a drive wheel that is rotatable about a horizontal central axis, a first drive for the wheel and a wheel holder, wherein the wheel holder is provided with a first holder member that can be attached to a mobile object, such as a vehicle or a transfer device, and a second holder member that engages the wheel and preferably in horizontal direction runs about the wheel, further comprising a steering drive for rotating the second holder member with respect to the first holder member about a substantially vertical central axis, preferably a purely vertical central axis, wherein the second holder member engages the first drive wheel, particularly a physical wheel axis thereof, preferably on both sides of the drive wheel, for conjoined rotation about the substantially vertical central axis. In that way a drive unit is provided that is compact in vertical and horizontal direction and controllable in the horizontal plane, that may be advantageous in many vehicles.

The second holder member can be annular or comprise one or more ring segment-shaped parts that are moveable as one unity with each other, which are rotatably guided about the said vertical central axis by the first holder member. In a compact embodiment the second holder member is situated within the first holder member, wherein particularly the first holder member comprises a hollow casing, particularly having a circular cross-section, and surrounds the second holder member therewith.

As stated above the steering drive may have a range of at least 90 degrees, preferably over 90 degrees, preferably over 180 degrees, preferably a range of 360 degrees or more. The first drive for the drive wheel can be arranged for conjoined steer rotation with the drive wheel by the steering drive.

The first drive may comprise a motor having a drive central axis that is substantially parallel to the central axis of rotation of the first drive wheel, particularly coincides therewith. The first drive particularly comprises a hub motor. The drive wheel may be provided with a compact electromotor that is placed in the centre of the wheel with surrounding tyre.

In a compact embodiment that can be deployed in a versatile manner, the steering drive in vertical sense is situated substantially below, preferably entirely below the upper side of the running surface of the drive wheel.

In a compact embodiment the vertical central axis of rotation of the steering drive intersects the running surface of the drive wheel. In that case the steering drive may intersect the plane in which the horizontal central axis of rotation of the drive wheel is situated. In a compact embodiment the first drive in vertical sense is situated substantially below, preferably entirely below the upper side of the running surface of the drive wheel.

In a further development the drive system according to the invention is provided with means for determining the angular position of the second holder member with respect to the first holder member. The drive system may furthermore comprise a control unit for controlling the first and/or steering drive in adjustment to the data from the means for determining the angular position.

The diameter of the drive wheel may be less than approximately 15 cm.

The drive system according to the invention may be provided with means for keeping the drive wheel in a set orientation (and thus movement direction).

The controllable drive system according to the invention is characterised by a very compact way of building. Especially the slight built-in height is advantageous in that respect. Such a system with slight built-in height is desirable in for instance a hospital environment wherein the drive can be moved fully or partially underneath a hospital bed. But also in a logistic process for loading a trailer, a low built-in height may be desirable because the driven wheel is able to move underneath the loading floor. The invention therefore particularly relates to a steered wheel that can be used as drive wheel for objects to be driven by themselves, such as roller containers and mobile vehicles such as service or work trolleys (for instance a sweeper or mower), and to mobile transfer devices, such as a forklift, goods platform carriage, hoist, transfer lift (for patients), operating table, hospital bed, for objects or persons that may or not be mobile.

The invention may in particular also relate to a steered wheel which in said mobile objects or transfer devices can be used as idling support wheel. According to a further aspect the invention provides a wheel system having a wheel that is rotatable about a horizontal central axis, and a wheel holder, wherein the wheel holder is provided with a first holder member that can be attached to a mobile object, such as a vehicle or a transfer device, and a second holder member that engages the wheel and preferably in horizontal direction runs about the wheel, wherein the second holder member is rotatable with respect to the first member about a substantially vertical central axis, preferably a purely vertical central axis, wherein the second holder member engages the first drive wheel, particularly a physical wheel axis thereof, preferably on both sides of the drive wheel, for conjoined rotation about the substantially vertical central axis, wherein the wheel system further comprises a steering drive for rotating the second member with respect to the first member. Further embodiments are described in the attached claims 69-78, the contents of which should be considered inserted in here. The steerable wheel system can be designed for a wheel that is idle or for a driven wheel. According to a further aspect the invention provides a drive system as described in the attached claims 79-91 , the contents of which should be considered inserted in here.

According to a further aspect the invention provides a mobile vehicle, particularly transfer device for a load, such as a person or an object, comprising a frame, wherein the frame is provided with one or more drive systems according to the invention, and one or more wheel systems with idle wheel according to the invention, particularly according to any one of the claims 68-76. The aspects and measures described in this description and the claims of the application and/or shown in the drawings of this application may where possible also be individually used where possible. Said individual aspects may be the subject of divisional patent applications relating thereto. This applies in particular to the measures and aspects described per se in the sub claims.

SHORT DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of a number of exemplary embodiments shown in the attached drawings, in which: Figures 1A-F show a diagonal front/top view, four bottom views and a side view, respectively, of a first embodiment of a device according to the invention;

Figures 2A and 2B show a diagonal front/top view and a bottom view, respectively, of a second embodiment of a device according to the invention;

Figures 3A and 3B show a diagonal front/top view and a bottom view, respectively, of a third embodiment of a device according to the invention; Figures 4A-F show a diagonal front/top view, four bottom views and a side view, respectively, of a fourth embodiment of a device according to the invention;

Figures 5A-E show a diagonal top view, an exploded view, a top view, a side view and a vertical cross-section, respectively, of a first exemplary embodiment of a steered drive unit according to the invention;

Figures 7A and 7B show a diagonal top view and a top view, respectively, of a second exemplary embodiment of a steered drive unit according to the invention; Figures 8A and 8B show a diagonal top view of a second exemplary embodiment of a steered drive unit according to the invention, in two operational positions;

Figures 9A and 9B show a diagonal top view of a third exemplary embodiment of a steered drive unit according to the invention, in two operational positions;

Figures 10A and 10B show a diagonal top view of a fourth exemplary embodiment of a steered drive unit according to the invention, in two operational positions;

Figures 11A and 11 B show a diagonal top view and an exploded view, respectively, of a fifth exemplary embodiment of a steered drive unit according to the invention;

Figures 12A and 12B show a diagonal top view of an exemplary embodiment of a blocking device for a steered drive wheel according to the invention; Figures 13A-E show a diagonal top view, a diagonal bottom view, an open top view and two operational position in side view, respectively, of an exemplary arrangement with a liftable steered drive unit according to the invention; Figures 14A and 14B show an exemplary embodiment of a liftable steered drive unit according to the invention, in two operational positions;

Figures 15A-D show three operational positions in side view, respectively, of an exemplary embodiment of a liftable double drive wheel according to the invention and a diagonal top view thereon;

Figures 16A and 16B show a diagonal front/top view and a side view, respectively, of a first exemplary embodiment of a device according to the invention with the liftable double drive wheel of figures 15A-D;

Figure 17 shows a diagonal front/top view of a second exemplary embodiment of a device according to the invention with the liftable double drive wheel of figures 15A-D; and Figures 18A-D show a diagonal front/top view, two operational positions in side view and a top view, respectively, of a third exemplary embodiment of a device according to the invention with the liftable double drive wheel of figure 15A-D.

DETAILED DESCRIPTION OF THE DRAWINGS

The invention will be elucidated on the basis of a number of exemplary embodiments shown in the attached drawings. In figures 1A-F a first known lifting device 1 is shown, a transfer lift for patients or motorised hoist. The device 1 comprises a frame 2, a main central axis S that runs in a direction from front to rear and with a rear side 1 a and a front side 1 b, wherein the frame 2 comprises a base 6 with legs 3 that extend forward and at the location of 5 are hinged to the base 6, so that the width of the dock or bay situated in between may vary and the required width to pass through (door) can be adjusted. At the rear side two transverse arms 4 extend that belong to the base 6 and are fixed thereto. From the base 6 a load bearer 8 movable with a cylinder 12 extends upwards and which at its outer end is provided with a load-engaging device 9, which for instance may comprise a hook that is not shown.

The frame 2 supports on four steerable drive wheels 7, accommodated in drive units 10, which drive units 0 are disposed at the ends of the legs 3 and arms 4. The drive wheels 7 are positioned according to a quadrangle. As can be seen in figure 1F the drive unit 10 to ^"be discussed further below, does not project above the rest of the leg 3, it even remains slightly below it. As a result the legs 3, despite being provided with steerable drive wheels 7, are able to get underneath a carrier with a low free space above the basis, such as the hospitable bed 100 in figure 1 F. The legs can just pass under the low frame pipes 101 and the load-engaging device 9 can be brought over a person on the bed at the correct location.

When the person is taken by the load bearer 8 a force G1 is exerted thereon. The resultant Fr of G1 and the device's 1 own weight G2 is in front of the base 6 and, as indicated in figure 1B, near the centre of the circumscribed circle of said quadrangle. As a result the overall load is advantageously distributed over the steerable drive wheels 7, as a result of which they are able to have sufficient grip/traction on the basis and manoeuvring is strongly enhanced.

Due to the steerability of the drive wheels 7 movement into all directions is easily possible. In figure 1 B forward or rearward, in figure 1C a swivelling motion to the right, in figure 1 D a rotation and in figure 1 E a movement in transverse direction. Particularly the rotation in figure 1 D is advantageous, wherein the device 1 would be able to circulate around the load, as is desirable in an environment with little room, such as a toilet or shower room. Figure 1 D also shows how the drive wheels 7 on the legs 3 can be placed transverse, so that by activation of the drive wheels 7 the legs can be swung about hinges 5 into a desired orientation. The drive wheels 7 can in that way also be used if the legs 3 by translation move (slide) apart and towards each other with respect to the base 6, while keeping their direction.

The legs 3 can then remain of a limited length. Weighting the base for improving traction is unnecessary, so that the weight of the device can remain limited. The lifting device 1 can also be designed with fewer drive wheels, see figure 2A,B and 3A,B. In device 1 of figures 2A,B only one leg 3 close to its outer end is provided with a drive unit 10, wherein both legs 3 and arms 4 are provided with a castor 11. Furthermore the base 6 is provided with a steerable drive wheel 7.

In the device 1 of figures 3A,B again only one leg 3 close to its outer end is provided with a drive unit 10, wherein the other leg 3 and one arm 4 are provided with a castor 11. Furthermore the other arm 4 is provided with a steerable drive wheel 7.

In figures 4A-F another exemplary embodiment of a device according to the invention is shown, wherein both legs 3 close to their outer ends are provided with a steerable drive wheel 7 and with a castor 11 , and the base 6 is also provided with a steerable drive wheel 7. Both arms are provided with castors 11. In this embodiment as well, in which there is question of three drive units, advantageous manoeuvring behaviour is achieved, as can be seen in figure 4B (forward, rearward), figure 4C (bend), figure 4D (rotation about itself) and figure 4E (transverse movement). Said Fr here again is close to the centre of the circumscribed circle of the drive points, see figure 4D.

The device according to the invention may comprise a control unit for controlling both direction of the drive motor and the speed and the steering direction of the wheel (rotation about steering axis). For operating direction, speed and steering direction one could think of a single or double joystick for the control, or a remote control or a touch sensitive system. The controller should be capable of controlling all drive units related to the desired steering direction (direction and speed).

The support legs with the drive unit can, despite the presence of a drive motor, be constructed low so that it can be moved underneath the bed.

In case such a lift is used in a care environment it is advantageous that the transfer lift for patients can to a large extent be moved underneath for instance a hospital bed. For that reason the support legs (3) need to be designed very low as according to current standards the minimum underpass room for such hospital beds should be 150 mm. The same issues can be recognized for an apparatus such as a forklift in which it should be possible to move the wheels of the support legs underneath the trailer or lorry. In case of a motorised hoist the same applies, the support legs should be capable of moving underneath the body of the vehicle.

The drive units 10 are very compact and have little height, despite the presence of a control for them. In figures 5-11 some examples are given.

The drive unit 10 shown in figures 5A-E comprises a drive wheel 7 with a hub motor 13 therein, a brushless out runner motor, optionally coupled to an internal planetary reducer which is able to let the hub of the wheel 7 with running surface 14 rotate about central axis H, in the desired direction and speed, forward or rearward.

The wheel 7 has two axle ends 15a,b that in a snugly fitting yet rotatable way are accommodated in vertical slots 16b of forks 16. The forks 16 form one unity with a flat ring 17, that is accommodated in a turning ring 18, for instance between two synthetic rings 18a,b having low frictional resistance. The turning ring 18 is fittingly accommodated in a straight circle-cylindrical housing/casing 19. The turning ring 18 at the bottom side rests against a flange 19' which forms one unity with the housing 19. The turning ring 18 provides for the positioned wheel hub motor 7 to be able to rotate in the horizontal, radial plane but is confined in the other directions. The housing 19 forms a first holder member of the wheel holder shown, and the ring 17 with forks 16 the second holder member.

The wheel 7 with running surface 14 will extend through the opening in flange 19a and is able to rotate without impediment about central axis H.

At the upper side the turning ring 18 is confined by a removable confining plate or pressure plate 20, which with lips 21 is attached to the housing 19. The confining plate 20 here consists of two parts 20a, 20b, a part 20a that is fixedly mounted to the housing 19 and a pressure plate 20b that can be adjusted such by means of adjustment bolts 22 that the turning ring bearing 18 reaches a correct pre-tension and the play can be adjusted. Said pressure plate 20b is connected to the fixed part 20a in a rotation-fixed manner by means of blocking pins 23, so that the plate 20b cannot rotate along about the vertical central axis V but can indeed be adjusted as regards height. A drive can be coupled to the rotatable part 16, 17 that holds the wheel 7. If it is desirable for the application, the wheel can be controlled in all directions of the compass in this way. In the example a toothed belt drive 24 is provided for that purpose, which comprises a belt driven plate 25 that is provided with holes 26 in which the upper ends 16a of the forks 16 snugly fit. Stops that are not shown on the forks 16 form a support for the plate 25, so that it will come to lie slightly above the upper edge of the housing 19, see figures 5D, 5E. In an engaged manner so as to drive, a toothed belt 27 runs about the plate 25 provided with drive teeth, and itself is driven by a second toothed wheel 28 which via transmission 29 is driven by an electromotor 30, steering motor. The steering motor 30, that can be attached to a rigid plate that is not shown and fixedly attached to casing 19, can be a motor for worm wheel transmission or another type of motor with or without mechanic end transmission. In certain cases it is desirable that the motor with reduction is self-locking and in that way capable of retaining the selected steering angle. In other cases this not desirable and the steering motor may act as an active steering servo. The steering motor is stationary with respect to the drive wheel that is rotatable about the vertical central axis of rotation V by the described steering drive, which central axis intersects the running surface 14. Due to the steering drive the drive wheel 7 can be rotated over 360 degrees and more about the central axis V.

In figures 5D and 5E it can be seen that the top point of the running surface 14 forms the highest point of the drive unit 10. The steering drive with steering motor 30, toothed belt 27, toothed belt plates 25, 28, fork 16 are below the horizontal plane H1 through said highest point. As a result the steering drive does not add construction height to the drive wheel 7 itself, as a result of which a low built-in height is achieved. The drive 13 for the wheel itself as well remains below said highest point. The drive unit 10 thus forms, other than by the wheel diameter, no determining factor in the height of frame sections of a device bearing said wheel. This is also shown in figure 1F, with hi as upper side level of leg 3 and with h2 as upper side level wheel 7, as highest point of the steerable drive unit 10. In figures 5A-5E an analogous angle detector 31 is also shown, which detects the rotation of the turning ring 25. It can also be measured at the axis of the steering motor 30 or in another way, where an angular rotation can be detected between the two parts that are rotated one to the other in the steering motion, namely the first holder member and the second holder member.

For reaching the desired steering angle by means of the steering motor and position feedback use can be made of known servo steering technique in combination with a suitable PID function.

An electronic control system 40 accommodated in the device 1 is adapted for controlling both the direction and the speed of the hub wheel motors 7 selectively, that means optionally independent from each other, and controlling the steering direction in the desired position by controlling the steering motor 30 also on the basis of the value of the angle detector.

In figure 6 it is shown that instead of a toothed belt or chain drive a toothed belt drive can be used, wherein a toothed wheel 32 driven by the steering motor 30 is in driving engagement with the toothed wheel 33, that forms one unity with the fork 16 that is not shown and which unity can be rotated about central axis V, so that rotation of toothed wheel 33 has the wheel 7 rotate. Due to the steering drive the drive wheel 7 can be rotated over 360 degrees and more about central axis V.

In figures 7A and 7B another alternative is shown, wherein within the housing 19 a wheel 37 is arranged, of which the (hollow) wheel shaft is driven by the outgoing shaft of right-angled transmission 35 engaging thereon that is driven by drive motor 36, wherein transmission 35 and motor 36 are fixedly attached to said flat ring 17, which with fork ends 16a is rotationally fixed with plate 38, which at the circumference is provided with teeth 39 that is driven by toothed wheel 98, driven by steering motor/servomotor 42 via right-angled transmission 41. Furthermore shown is an angle detector 31 detecting the steering angle and provides the central control unit with said information. In this embodiment the drive wheel 37 is free on one side. Here as well the said low construction height is achieved. Because of the steering drive the drive wheel 7 can be rotated over 360 degrees and more about central axis V. In the figures 8A,B, 9A,B and 10A.B further alternatives are shown, in which said low construction height is achieved again. In all these cases use is made of an electrically adjustable linear actuator 45. In figures 8A,B the actuator 35 drives a rack 46, which is in toothed engagement with a toothed wheel plate 47 that forms one unity with wheel 7, which unity can be rotated about central axis V. In figures 9A,B the extendable outer end of the actuator 45 is attached to the end of a supple toothed belt 48, which drives toothed wheel 47 and at the other end is attached to a spring 49 with which a correct engagement of the belt 48 onto the toothed wheel 47 is ensured. In figures 10A.B the extendable outer end of the actuator 45 is attached to the plate 51 so as to hinge by means of a hinge pin 50, which plate at rotation about the central axis V rotates the wheel 7 along.

Yet another embodiment is shown in figures 11A,B in which first and second holder members cooperate in the form of an electromotor. In this case a ring 55 of permanent magnets is attached to the plate 25 and to the housing 19, at the inner surface, a ring of electromagnets 56. Said electromagnets 56 can be controlled in three phases or as stepping motor. The structure thus created forms an electromotor that is able to control the wheel 7 with hub wheel motor about central axis V over a range of more than 360 degrees.

The controllable hub wheel motor may optionally be controlled in a mechanical manner by means of cables, rods and chains.

In all cases the diameter of the rotatable portion can remain limited, whereas furthermore the height is limited.

In one type of embodiment means are provided for preserving the desired steering position if it is reached. This is for instance possible with a worm wheel transmission in the steering motor that is designed so as to be self-locking, as a result of which if a certain steering position is reached, said position will not change. Another possibility is using a mechanical blocking system, with which the steering angle can be locked in a predetermined steering angle. An example is given in figures 12A,B in which a part, the plate 25, that rotates along with steering the part directing the wheel (second holder member) is provided with a number of recesses 60 at the circumference. On either side of the plate 25 hooks 61 a, b are positioned, that are urged towards each other by spring force (62) and thus urged into the recesses 60. The hooks can be unlocked by urging them apart, for instance using solenoids 63a, b or an actuator, servo operation or cable operation. This blocking mechanism too can be designed such that it remains below the uppermost point of the running surface 14.

Blocking may also include a friction brake of which the drum or disk rotates along with the turning ring or on the control motor. Said friction brake can then be blocked with the required holding force when a certain steering angle has been reached. The mechanical blocking or the friction brake action then needs to be actively ended if another steering direction is wanted. Ending the blocking can for instance take place in an electromechanical manner or mechanical manner, using a solenoid or an actuator.

The system with a mechanical blocking has the advantage that the steering motor is able to make a steering angle very quickly and does not need to take care of blocking as soon as the steering angle has been reached. As a result a compact motor can be used with a high speed wherein the motor itself need not generate the holding power.

For reaching the desired steering angle it may be necessary to use a system with a feedback of the current steering angle. This may be an analogous or digital angle detector, a pulse counter or switch points.

As already shown in figures 1-4 several of this type of steerable drive systems can be placed under a vehicle. In that way it can be made possible that the vehicle is able to ride/move in all compass directions. An electronic control unit may then ensure that all steerable wheels are steered in the correct direction with respect to each other. It may also be necessary that the control unit ensures the differential operation of the various wheels, depending on the required individual speed of revolution per wheel related to the position and drive direction of the vehicle.

It is also possible that the control takes place entirely mechanically, by means of connection cables or chains or knuckle arms or a combination thereof between the various steering wheels. The wheel hub motor can be provided with a mechanical or electromechanical brake. The motor itself can also serve as countertorque brake. One aspect of an embodiment of the system according to the invention is that the motor for the wheel is placed directly inside the turning ring.

Instead of a drive wheel, particularly hub wheel motor, the examples given can also be used with an idling wheel.

For certain applications it may be desirable to pull the drive wheel up from the floor. This is handy when it regards a vehicle that can also be moved by other means. For instance a hauling vehicle or manually on muscular force. This may for instance facilitate positioning unloaded without drive.

If the driven wheel is pulled upwards the vehicle will rest or be moveable on another wheel that is not driven. This may for instance be a castor.

In order to make this possible the controllable drive system can be attached to the frame such that it can move in the vertical plane. In figures 13-15 examples thereof are given.

In figures 13A-E a first example of a pull-up mechanism 70 is shown for a drive unit 10 close to the outer end of a leg 3. The mechanism 70 comprises an actuator 71 which with the one end is hinged to a transverse pin 71 that in manner not further shown is location-fixedly attached in the leg 3 and with the other, movable outer end is hinged to a transverse pin 73, which via strips 74 is connected to a transverse pin 75 that is also attached to the walls 3a, b. The end of a gas spring 76 is also hinged to the transverse pin 73, which gas spring with the other end is hinged to an L-shaped lever 77. The lever 77 is hinged on the transverse pin 72. The horizontal leg 77a of the lever 77 extends between two pins 78a, b that are arranged respectively on an upper and lower rod 79a, b of a parallelogram structure. At the location of pins 80a,b, the upper and lower rods 79a, b are hinged to the wall 3a. It will be understood that a comparable parallelogram structure is arranged on wall 3b as well. The other ends of the rods 79a, b are hinged to the housing 19 at the location of pins 81 a,b. When the drive wheel 7 has to be pulled up the housing 19 is pulled up as well, see figure 13D. This takes place by operating the actuator 71 , as a result of which the pin 73 in the drawing is urged to the left, the lever 77 is turned anti-clockwise and lever leg 77a exerts a lifting force on pins 78a. The rods 79a, b are then urged upwards, hinging about pins 80a, b. The leg outer end 3 then only rests on the castor 11. When the drive wheel 7 has to be lowered the actuator 71 is operated in the other direction. The gas spring 72 is moved to the right, and the lever 77 is turned clockwise, as a result of which the lever leg 77a pushes the pins 78a downwards. The running surface 1 of the wheel 7 then contacts the ground, and by operating the actuator 71 further the gas spring 72 is pushed in, as a result of which the lever leg 77a is forcefully pushed against the pins 78b and thus the wheel 7 is pushed against the ground for sufficient traction. The pull-up mechanism may for instance consist of a linear actuator having a pulling cable or another pull-up motor with eccentric system or lever. A mechanical pull-up function can also be opted for, for instance a spindle or hand brake handle with hold function connected by means of a cable. In that way the drive units are positioned such that they can be lifted from the ground, so that the device at that location still supports on the castors only. In that situation moving freely without drive is possible.

Another embodiment, among others suitable for the drive unit of figures 11A.B is shown in figures 14A.B. In the leg 3 an actuator 85 is arranged, the extendable end of which is hinged to a U-shaped holder 86. The legs 86a,b of the holder 86 are provided with horizontal slots 87a, b and with run-up edges 88a, b. The housing 19 is accommodated in a tube 89 so as to be vertically slidable, which tube is provided with vertical slots 90a, b. Transversely extending pins 91 a, b are attached to the tube 89 and extend into the slots 87a,b. Transversely extending pins 19a,b are attached to the housing 19 and extend into the slots 90a, b. When operating the actuator 85 from the position of figure 1 A the holder 86 is retracted and the pins 19a, b run over the edges 88a, b and are then urged upwards. The housing 19 follows said movement, so that the wheel 7 comes off the ground. For placing the wheel 7 back on the ground again the order is reversed. A spring element that is not shown can be present for tensioning the wheel downwards against the ground. It is noted that the principles shown can also be used on wheels that can be pulled up without steering and/or without drive. Another example of an arrangement for pulling up (drive) wheels is shown in figures 15A-D. There is question here of a pair 201 a,b of driven wheels, that have a fixed bearing and with their central axes of rotation are oriented perpendicular to each other. Due to an operable tilting mechanism either the one or the other drive wheel, or both drive wheels can be lifted off from the basis. Steering can then be done manually or by electronic differential operation between the motors.

In figures 15A-D a pull-up mechanism 200 is shown that is provided with two drive wheels 201a, 201 b having central axes Sa, Sb that are perpendicular to each other. Both wheels are borne by an auxiliary frame 203 that comprises a frame section 203a for drive wheel 201a and a frame section 203b for drive wheel 201b. The auxiliary frame 203 is hinged to a downward leg 204a of a beam 204, which itself at one end is hinged to an inverted U-frame 202 that is attached to the frame 2, 3, 6. The beam 204 is tensioned downwards by a gas spring 205 and can be swung upwards and downwards by an actuator 206. A second actuator 207 at one end is hinged to the beam 204 and with the other movable end is hinged to an upright leg 203c of the auxiliary frame 203.

The orientation of the auxiliary frame 203 in the vertical plane that contains the indicated direction A is thus determined by means of two actuators 206,207.

In figure 15A, by operating the actuator 207, the auxiliary frame 203 is adjusted for an extending movement in order to keep the drive wheel 201 b in contact with the basis in order to effect movement in direction A, in figure 15C by operating the actuator 206 for a retracting movement in order to keep the drive wheel 201a in contact with the basis in order to effect movement in the direction B. In both cases the gas spring 205 ensures an increase of the pressing force of the wheel in question against the basis. In figure 15C the auxiliary frame is adjusted to keep both drive wheels 201 a, b in the free position. For that purpose the actuator 206 is operated for a retracting movement, counter the action of the gas spring 205. In figures 16A.B a use of the pull-up mechanism 200 with tiltable drive wheel pair of figures 15A-D is shown, built in in the base 6. In figure 17 it is shown that such a drive wheel pair can also be housed in one or both legs. In case they are oriented in the same direction the device can be driven in two main directions that are perpendicular to each other, after selection of the drive wheels thereof, wherein in case there is question of a differential between both pairs of drive wheels a curved path can also be traversed. In that case the wheels 201a can be used for moving the legs 3 apart or towards each other, see directions C. In figures 18A-D an example is shown of a forklift suitable for moving pallets provided with the invention, having parallel legs 3, in each of which a tiltable drive wheel pair 200 is arranged.

Extending the support legs can therefore take place in at least two ways, namely by releasing the drive unit from the basis and then moving the legs rolling on castors, or by steering the drive units in the position so that the axis line of the wheel intersects the point of rotation of the support leg. The support legs can then be adjusted, possibly even be driven by the drive unit. It is advantageous here if the angle of the support leg 3 and the base 6 of the assembly can be electronically measured so that the wheel in the steering direction can be correctly controlled with respect to the base of the assembly. A sensor 95 that is functionally connected to the control unit 40 is shown in figure 1 D.

Each drive unit 10 can also be provided with a position sensor, for instance a potentiometer or angle detector so that the control electronics have data about the steering angle in which the wheel is at any moment. By on the basis of data of the position sensor of the drive unit 10 controlling each wheel in relation to each other yet independently, the device 1 according to the invention can be ridden/moved in any position.

For instance the correct tracking of the wheels with respect to each other and also steering according to the Ackermann principle in any direction of movement can be carried out electronically. Also taking the angle in which the support legs are placed into account. The invention provides an electric drive system which provides that moving a rolling load in any compass direction can take place in a simple manner and using as little physical effort as possible.

By means of the drive system both the direction as well as the speed can be electronically controlled/operated.

It is noted that castors also include swivel balls.

It is noted that instead of two legs there can be question of one forwardly projecting platform, and that spaced apart from the base one or more drive wheel units according to the invention are arranged. The above description is included to illustrate the working of preferred embodiments of the invention, and not to limit the scope of the invention. Starting from the above elucidating many variations that fall under the spirit and the scope of the present invention will be clear to an expert.

Claims

1. Mobile vehicle, particularly transfer device for a load, such as a person or an object, comprising a frame with an operation or front side and a rear side, a base situated at the rear side and at least one leg connected to the base and extending therefrom usually to the front side, preferably in horizontal direction, preferably two such legs, wherein the frame is provided with a load bearer, wherein at least one leg, viewed along the leg, at a location spaced apart from the base is provided with a first drive wheel, wherein the drive wheel comprises a first drive, such as a motor, which in vertical sense is substantially below, preferably entirely below the upper side of the running surface of the first drive wheel in operational position, wherein a first direction control for the first drive wheel for steering the orientation of the first drive wheel with respect to the leg is at least partially, preferably substantially, arranged on the leg.

2. Vehicle according to claim 1 , wherein the first direction control comprises a first steering drive for adjusting the orientation of the first drive wheel, wherein in vertical sense the first steering drive is substantially below, preferably entirely below the upper side of the running surface of the first drive wheel in operational position.

3. Vehicle according to claim 1 or 2, wherein the first direction control comprises a first steering drive for adjusting the orientation of the first drive wheel, wherein the first steering drive comprises a motor that is placed stationary with respect to the drive wheel.

4. Vehicle according to claim 2 or 3, wherein the first steering drive intersects the plane in which the horizontal central axis of rotation of the drive wheel is situated.

5. Vehicle according to claim 2, 3 or 4, wherein the first steering drive comprises a wheel holder having a first holder member that is attached to the first leg and a second holder member which with respect to the first holder member is rotatable about a substantially vertical central axis, particularly a purely vertical central axis, wherein the second holder member engages onto the first drive wheel, particularly a physical wheel axis thereof, preferably on both sides of the drive wheel, for conjoined rotation about the substantially vertical central axis.

6. Vehicle according to the claim 5, wherein the second holder member is annular or comprises one or more ring segment-shaped parts that are movable as one unity with each other, which are rotatably guided about the said vertical central axis by the first holder member.

7. Vehicle according to claim 5 or 6, wherein the first drive is placed with the wheel inside the first holder member and within it rotatably about the vertical central axis, particularly placed inside a turning ring that is formed by the first and second holder member.

8. Vehicle according to claim 5, 6 or 7, wherein the first holder member comprises a hollow casing, particularly having a circular cross-section, and surrounds the second holder member therewith.

9. Vehicle according to any one of the preceding claims, wherein the first direction control has a range of at least 90 degrees, preferably over 90 degrees, preferably 180 degrees or more, preferably a range of 360 degrees or more.

10. Vehicle according to any one of the preceding claims, wherein the first direction control comprises means for detecting the orientation of the first drive wheel with respect to the leg.

11. Vehicle according to any one of the preceding claims, wherein the first drive for the first drive wheel is arranged for conjoined steer rotation with the fist drive wheel by the first direction control.

12. Vehicle according to any one of the preceding claims, wherein the first drive comprises a motor having a drive central axis that is substantially parallel to the central axis of rotation of the first drive wheel, particularly coincides therewith, wherein preferably the first drive comprises a hub motor.

13. Vehicle according to any one of the preceding claims, wherein the upper slide of the running surface of the first drive wheel defines the highest point of the leg in question, at least the part of the leg in question which is situated near the first drive wheel and further towards the front side.

14. Vehicle according to any one of the preceding claims, wherein the diameter of the first drive wheel is less than approximately 15 cm.

15. Vehicle according to any one of the preceding claims, wherein the leg is provided with the first drive wheel at a location close to its outer end.

16. Vehicle according to any one of the preceding claims, with two of said legs that are provided with the first drive wheel and a second drive wheel, respectively, preferably at a location close to the outer end of the leg in question, wherein, preferably, the first and the second drive wheels with their first and second drive, respectively, are designed so as to be mutually similar.

17. Vehicle according to claim 16, wherein the second drive wheel is provided with a second direction control, which preferably is designed in accordance with the first direction control, wherein the vehicle preferably is provided with a central control unit for controlling the first and second direction control in a mutually adjusted and selective manner.

18. Vehicle according to any one of the preceding claims, wherein at least one leg, preferably both legs, is/are connected to the base so as to be movable, preferably adjustable, in a horizontal plane.

19. Vehicle according to claim 18, wherein at least one leg, preferably both legs, are connected to the base so as to be rotatable in a horizontal plane.

20. Vehicle according to claim 18 or 19, wherein at least one leg, preferably both legs, is/are connected to the base so as to be linearly moveable in a horizontal plane, preferably in a direction transverse to the leg in question.

21. Vehicle according to claim 18, 19 or 20, wherein the first/second direction control permit an orientation of the drive wheel in question with which the desired movement of the leg with respect to the base is made possible, particularly an orientation transverse to the leg.

22. Vehicle according to any one of the preceding claims, wherein the direction control comprises means for steering the orientation of the drive wheel with respect to the leg while preserving the direction of said drive wheel with respect to the world.

23. Vehicle according to any one of the preceding claims, wherein the direction control comprises means for steering the orientation of the drive wheel with respect to the world.

24. Vehicle according to any one of the preceding claims, depending on claim 2, wherein the vertical central axis of rotation of the steering drive in question intersects the running surface of the drive wheel in question.

25. Vehicle according to any one of the preceding claims, depending on claim 2, wherein the vertical central axis of the steering drive in question intersects the horizontal central axis of rotation of the drive wheel in question.

26. Vehicle according to any one of the preceding claims, wherein the base is provided with at least one further drive.

27. Vehicle according to claim 26, provided with a further direction control for the further drive wheel for steering the orientation of the further drive wheel with respect to the base.

28. Vehicle according to claim 27 and claim 16 or a claim depending thereon, wherein the first, second and further drive wheels are positioned according to a polygon, particularly a triangle.

29. Vehicle according to claim 28, wherein the load bearer is provided with a load- engaging device that engages the load with a resultant force which in horizontal direction, in the direction towards the front side of the frame, is spaced apart from the base and, considered in projection on a horizontal plane, is situated within the polygon, at least near the centre of the described circle of said polygon.

30. Vehicle according to any one of the preceding claims, when depending on claim 16, wherein the load bearer is provided with a load-engaging device that engages the load with a resultant force which in horizontal direction, in the direction towards the front side of the frame, is spaced apart from the base, wherein the load-engaging device considered in projection on a horizontal plane is active between the legs, wherein preferably both legs are provided with a drive wheel in question at a location spaced apart from the base.

31. Vehicle according to any one of the claims 1-15, wherein the leg forms a platform with a support surface for a load to be moved.

32. Vehicle according to claim 31 , wherein the leg is provided with both the first drive wheel and a second drive wheel, preferably at a location close to the outer end of the leg, wherein, preferably, the first and the second drive wheels with their first and second drive, respectively, are designed so as to be mutually similar.

33. Vehicle according to claim 32, wherein the second drive wheel is provided with a second direction control, which preferably is designed in accordance with the first direction control, wherein the vehicle preferably is provided with a central control unit for controlling the first and second direction control in a mutually adjusted and selective manner.

34. Vehicle according to any one of the preceding claims, wherein the first and/or second drive wheel is adjustable in the position thereof along the leg in question.

35. Vehicle according to any one of the preceding claims, wherein the leg provided with the drive wheel is provided with an additional castor, preferably on the distal side of the drive wheel.

36. Vehicle according to claim 35, wherein the leg in question is provided with a lifting means for moving the drive wheel between an operational position in contact with a basis and a free position at a distance therefrom.

37. Vehicle according to claim 36, wherein the upper side of the drive wheel in the free position remains within the transverse profile of the leg in question, preferably is situated at a distance of approximately 30 cm or less, preferably 15 cm or less above the basis.

38. Vehicle according to any one of the preceding claims, wherein the frame is supported also by means of one or more castors, wherein preferably on the rear side, on both sides of the base, castors are present.

39. Mobile vehicle, particularly a vehicle according to any one of the preceding claims, provided with a double drive wheel having a primary drive wheel and a secondary drive wheel, of which the horizontal central axes are perpendicular to each other, wherein the primary and the secondary drive wheel are provided with a lifting means for selectively moving the primary drive wheel between an operational position in contact with a basis and a free position at a distance therefrom and simultaneously the secondary drive wheel in opposite sense, and vice versa.

40. Vehicle according to claim 39, wherein the primary and the secondary drive wheel are supported in an auxiliary frame, that is attached in the frame so as to be tiltable between a position in which the primary drive wheel is in the operational position and a position in which the secondary drive wheel is in the operational position, wherein, preferably, the auxiliary frame can be placed in an intermediate position in which both drive wheels are free.

41. Vehicle according to claim 39 or 40, wherein the primary and secondary drive wheels are each provided with their own motor, so that the one drive wheel is driven by the one motor and the other drive wheel is driven by the other motor that preferably is identical to the one motor.

42. Vehicle according to claim 39, 40 or 41 and claim 16 or a claim depending thereon, wherein the double drive wheel is arranged in the second leg.

43. Vehicle according to any one of the preceding claims, wherein the load bearer is designed as lifting means for a person, particularly to be used as a transfer lift.

44. Mobile vehicle, particularly transfer device for a person, comprising a frame having a base and two legs protruding therefrom, wherein the legs between them form a space, such as a dock or bay, for offering room to the load, wherein at least one of the legs at a location at a distance from the base is provided with a drive wheel and with means for with respect to the leg steering the drive wheel, particularly drive wheel with its drive.

45. Mobile vehicle, particularly transfer device for an object, such as a forklift, comprising a frame having a base and two legs protruding therefrom, wherein the legs between them form a space, such as a dock or bay, for offering room to the load, wherein at least one of the legs at a location at a distance from the base is provided with a drive wheel and with means for with respect to the leg steering the drive wheel, particularly drive wheel with its drive, wherein the drive wheel can be steered over an angular range of at least 90 degrees, preferably over 90 degrees, preferably over 180 degrees, preferably an angular range of 360 degrees or more.

46. Vehicle, particularly transfer device, according to claim 45, provided with one or more of the measures described in any one of the claims 1-38.

47. Vehicle, particularly transfer device, according to any one of the preceding claims, wherein the load bearer bears suspended therefrom a load-engaging device, such as a hook.

48. Vehicle, particularly transfer device, according to claim 47, wherein the load- engaging device is designed to be a suspension device for a person, particularly to be used as a transfer lift.

49. Vehicle, particularly transfer device, according to claim 47, wherein the load- engaging device is designed to be a suspension device for an object, particularly to be used as a hoist.

50. Vehicle, particularly transfer device, according to any one of the claims 1-46, wherein the load-engaging device forms a load support surface on the load bearer.

51. Vehicle, particularly transfer device, according to claim 50, wherein the load- engaging device is designed to be a forklift for lifting pallets or other objects.

52. Drive system having a drive wheel that is rotatable about a horizontal central axis, a first drive for the wheel and a wheel holder, wherein the wheel holder is provided with a first holder member that can be attached to a mobile object, such as a vehicle or a transfer device, and a second holder member that engages the wheel and preferably in horizontal direction runs about the wheel, further comprising a steering drive for rotating the second holder member with respect to the first holder member about a substantially vertical central axis, preferably a purely vertical central axis, wherein the second holder member engages the first drive wheel, particularly a physical wheel axis thereof, preferably on both sides of the drive wheel, for conjoined rotation about the substantially vertical central axis.

53. Drive system according to claim 52, wherein the second holder member is annular or comprises one or more ring segment-shaped parts that are moveable as one unity with each other, which are rotatably guided about the said vertical central axis by the first holder member.

54. Drive system according to claim 52 or 53, wherein the first drive is placed with the wheel inside the first holder member and within it rotatably about the vertical central axis, particularly placed inside a turning ring that is formed by the first and second holder member.

55. Drive system according to claim 52, 53 or 54, wherein the second holder member is situated within the first holder member, particularly the first holder member comprising a hollow casing, particularly having a circular cross-section, and surrounds the second holder member therewith.

56. Drive system according to any one of the claims 52-55, wherein the first steering drive has a range of at least 90 degrees, preferably over 90 degrees, preferably over 180 degrees, preferably a range of 360 degrees or more.

57. Drive system according to any one of the claims 52-56, wherein the first drive for the drive wheel is arranged for conjoined steer rotation with the drive wheel by the steering drive.

58. Drive system according to any one of the claims 52-57, wherein the first drive comprises a motor having a drive central axis that is substantially parallel to the central axis of rotation of the first drive wheel, particularly coincides therewith.

59. Drive system according to claim 58, wherein the first drive comprises a hub motor.

60. Drive system according to any one of the claims 52-59, wherein the steering drive in vertical sense is situated substantially below, preferably entirely below the upper side of the running surface of the drive wheel.

61. Drive system according to any one of the claims 52-60, wherein the drive wheel comprises a drive which in vertical sense is situated substantially below, preferably entirely below the upper side of the running surface of the drive wheel.

62. Drive system according to any one of the claims 52-61 , wherein the vertical central axis of rotation of the steering drive intersects the running surface of the drive wheel.

63. Drive system according to claim 62, wherein the steering drive intersects the plane in which the horizontal central axis of rotation of the drive wheel is situated.

64. Drive system according to any one of the claims 52-63, provided with means for determining the angular position of the second holder member with respect to the first holder member.

65. Drive system according to claim 64, comprising a control unit for controlling the first and/or steering drive in adjustment to the data from the means for determining the angular position.

66. Drive system according to any one of the claims 52-65, wherein the diameter of the drive wheel is less than approximately 15 cm.

67. Drive system according to any one of the claims 52-66, provided with means for keeping the drive wheel in a set orientation.

68. Wheel system having a wheel that is rotatable about a horizontal central axis, the wheel preferably having a diameter of approximately 15 cm or less, and a wheel holder, wherein the wheel holder is provided with a first holder member that can be attached to a mobile object, such as a vehicle or a transfer device, and a second holder member that engages the wheel and preferably in horizontal direction runs about the wheel, wherein the second holder member is rotatable with respect to the first member about a substantially vertical central axis, preferably a purely vertical central axis, wherein the second holder member engages the first drive wheel, particularly a physical wheel axis thereof, preferably on both sides of the drive wheel, for conjoined rotation about the substantially vertical central axis, wherein the wheel system further comprises a steering drive for rotating the second member with respect to the first member.

69. Wheel system according to claim 68, wherein the second holder member is annular or comprises one or more ring segment-shaped parts that are moveable as one unity with each other, which are rotatably guided about the said vertical central axis by the first holder member.

70. Wheel system according to claim 68 or 69, wherein the first drive is placed with the wheel inside the first holder member and within it rotatably about the vertical central axis, particularly placed inside a turning ring that is formed by the first and second holder member.

71. Wheel system according to claim 68, 69 or 70, wherein the second holder member is situated within the first holder member, particularly the first holder member comprising a hollow casing, particularly having a circular cross-section, and surrounds the second holder member therewith.

72. Wheel system according to any one of the claims 68-71 , wherein the steering drive has a range of at least 90 degrees, preferably over 90 degrees, preferably over 180 degrees, preferably a range of 360 degrees or more.

73. Wheel system according to any one of the claims 68-72, wherein the steering drive in vertical sense is situated substantially below, preferably entirely below the upper side of the running surface of the drive wheel.

74. Wheel system according to any one of the claims 68-73, wherein the steering drive intersects the plane in which the horizontal central axis of rotation of the wheel is situated and/or wherein the vertical central axis of rotation of the steering drive intersects the running surface of the drive wheel.

75. Wheel system according to any one of the claims 68-74, provided with means for determining the angular position of the second holder member with respect to the first holder member.

76. Wheel system according to any one of the claims 68-75, wherein the wheel is idle.

77. Wheel system according to any one of the claims 68-75, wherein the wheel is driven, wherein the wheel system further comprises a drive for said wheel, preferably a motor attached to the wheel for conjoined rotation therewith about the vertical central axis of rotation.

78. Wheel system according to any one of the claims 68-77, provided with means for keeping the wheel in a set orientation.

79. Drive system having a drive wheel that is rotatable about a horizontal central axis, a first drive for the wheel, and a wheel holder, wherein the wheel holder is provided with a first member that can be attached to a mobile object, such as a vehicle or a transfer device, and a second member that engages the wheel and preferably in horizontal direction runs about the wheel, wherein the second member is rotatable with respect to the first member about a substantially vertical central axis, wherein the drive system further comprises a second (steering) drive for rotating the second member with respect to the first member.

80.Drive system according to claim 79, wherein the second member is situated within the first member.

81. Drive system according to claim 79 or 80, wherein the second drive in vertical sense is situated substantially below, preferably entirely below the upper side of the running surface of the drive wheel.

82. Drive system according to claim 81 , wherein the second drive intersects the plane in which the horizontal central axis of rotation of the drive wheel is situated.

83. Drive system according to any one of the claims 79-82, provided with means for determining the angular position of the second member with respect to the first member.

84. Drive system according to claim 83, comprising a control unit for controlling the first and/or second drive in adjustment to the data from the means for determining the angular position.

85. Drive system according to any one of the claims 79-84, wherein the first member forms a vertical bush, preferably having a circular cross-section.

86. Drive system according to any one of the preceding claims, wherein the vertical central axis intersects the horizontal central axis.

87. Drive system according to any one of the claims 79-85, wherein the second drive has a range of at least 180 degrees, preferably a range of 360 degrees or more.

88. Drive system according to any one of the claims 79-87, wherein the drive wheel comprises a drive that in vertical sense is situated substantially below, preferably entirely below the upper side of the running surface of the drive wheel.

89. Drive system according to claim 88, wherein the drive wheel has a hub motor.

90. Drive system according to any one of the claims 79-89, wherein the diameter of the drive wheel is less than approximately 15 cm.

91. Drive system according to any one of the claims 79-90, provided with means for keeping the drive wheel in a set orientation.

92. Vehicle according to claim 5 or a claim depending thereon, wherein the first and second holder members cooperate in the form of an electromotor, wherein on the one holder member, preferably the first holder member, a ring of electromagnets is attached and on the other holder member, preferably the second holder member, a ring of permanent magnets is attached.

93. Drive system according to any one of the claims 52-67 or 79-91 , wherein the first and second holder members cooperate in the form of an electromotor, wherein on the one holder member, preferably the first holder member, a ring of electromagnets is attached and on the other holder member, preferably the second holder member, a ring of permanent magnets is attached.

94. Wheel system according to any one of the claims 68-78, wherein the first and second holder members cooperate in the form of an electromotor, wherein on the one holder member, preferably the first holder member, a ring of electromagnets is attached and on the other holder member, preferably the second holder member, a ring of permanent magnets is attached.

95. Mobile vehicle, particularly transfer device for a load, such as a person or an object, particularly a vehicle according to any one of the claims 1-51 , 92 comprising a frame, wherein the frame is provided with one or more drive systems according to any one of the claims 52-67 or 79-93, and one or more wheel systems according to any one of the claims 68-76, 94.

96. Drive system provided with one or more of the characterising measures described in the attached description and/or shown in the attached drawings.

97. Wheel system provided with one or more of the characterising measures described in the attached description and/or shown in the attached drawings.

98. Vehicle provided with one or more of the characterising measures described in the attached description and/or shown in the attached drawings.