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Title:
DEVICE AND METHOD FOR TRANSPORTING OBJECTS
Document Type and Number:
WIPO Patent Application WO/2015/069105
Kind Code:
A1
Abstract:
The invention relates to a device (10) for transporting objects (0), comprising: - a frame (18) movable in one or more transport directions; - a first gripper arm (22) and second gripper arm (23) arranged on the frame; - a displacing unit (16) for displacing the gripper arms between respective transport positions, in which an object can be transported, and gripping positions in which an object can be grasped; wherein at least one of the gripper arms is provided on the side facing toward the opposite gripper arm with at least one flexible unit comprising a flexible element (36) for filling selectively with a medium, in particular a stretchable membrane for filling with medium; - a medium feed unit (95) for feeding medium to one or more of the flexible elements for the purpose of clamping the object.

Inventors:
OSTERLOH, Edwin (De Beuk 63, ZB Didam, NL-6941, NL)
LALESSE, Robert (Spinet 37, PD Zevenaar, NL-6904, NL)
Application Number:
NL2014/050765
Publication Date:
May 14, 2015
Filing Date:
November 04, 2014
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
OX2 B.V. (De Beuk 63, ZB Didam, NL-6941, NL)
International Classes:
B65G47/90; B65G1/04
Foreign References:
DE102011010557A12012-08-09
US20060033350A12006-02-16
US5964562A1999-10-12
NL2005966C2012-07-10
US20090136331A12009-05-28
Attorney, Agent or Firm:
HYLARIDES, Paul, Jacques (Bezuidenhoutseweg 57, AC Den Haag, NL-2594, NL)
Download PDF:
Claims:
CLAIMS

1. Device for transporting objects, comprising:

- a frame on which is arranged at least one gripper arm displaceable relative to the frame, wherein the gripper arm is provided with at least one flexible unit comprising:

- at least one flexible element for filling with medium and expandable in at least one direction;

- an expanding unit configured to expand the expandable flexible element in said direction for the purpose of grasping the object;

- a displacing unit for displacing the at least one gripper arm between at least one transport position, in which at least one object can be transported, and a gripping position in which at least one object can be grasped.

2. Device as claimed in claim 1 , wherein the expanding unit comprises a medium feed unit which is configured to expand the flexible element from a release position to a gripping position by feeding medium to a medium chamber thereof.

3. Device as claimed in claim 2, wherein the expanding unit also comprises a medium discharge unit which is configured to discharge medium from one or more flexible elements in order to bring the flexible element from the gripping position to the release position.

4. Device as claimed in any of the foregoing claims, wherein the medium chamber of the flexible element comprises a flexible balloon for filling with medium. 5. Device as claimed in any of the foregoing claims, wherein the flexible element comprises a medium chamber for filling with medium, wherein at least one wall of the medium chamber, in particular the wall of a flexible balloon, is manufactured from one or more flexible materials, in particular elastic materials. 6. Device as claimed in any of the foregoing claims, comprising an actuator which is arranged for the purpose of pressing the flexible element inward on one side in order to displace another side of the flexible element from a release position to a gripping position.

7. Device as claimed in any of the foregoing claims, comprising a first gripper arm and second gripper arm arranged on the frame, wherein the first and second gripper arms extend substantially parallel relative to each other and wherein at least one of the gripper arms is provided with at least one flexible element which is airanged so as to be expandable in the direction of the opposite gripper arm.

8. Device as claimed in any of the foregoing claims, comprising a first gripper arm and second gripper arm arranged on the frame, wherein the first and second gripper arms extend substantially parallel relative to each other and wherein the two gripper arms are provided with one or more flexible elements which are arranged so as to be expanded in the direction of the opposite gripper arm in order to fixedly clamp one or more objects therebetween. 9. Device as claimed in any of the foregoing claims, wherein the frame is a frame movable in one or more transport directions.

10. Device as claimed in any of the foregoing claims, wherein a gripper arm comprises: - an elongate support part arranged slidably along the frame;

- at least one row of flexible elements arranged in the support part.

11. Device as claimed in claim 10, wherein the support part has a flat component and wherein the flexible element can be arranged between a release position, in which the flexible element is substantially flush with the flat component, and a gripping position in which the flexible element protrudes relative to the flat component due to expansion.

12. Device as claimed in any of the foregoing claims, comprising two or more flexible elements arranged in a gripper arm and a control unit for controlling the medium feed unit, preferably also for controlling a medium discharge unit, wherein the control unit and the flexible elements are configured to selectively expand the flexible elements.

13. Device as claimed in claim 12, wherein the control unit is configured to expand a first number of the flexible elements of a gripper arm and to hold a first number of the flexible elements of the gripper arm in flat state.

14. Device as claimed in any of the foregoing claims, comprising of bringing flexible elements of different gripper arms provided at mutually opposite positions substantially synchronously to an expanded state or a flat state. 15. Device as claimed in any of the foregoing claims, wherein by feeding and discharging medium the flexible element can be arranged between a release position, in which the volume taken up by the flexible element is relatively small, and a clamping position in which the volume taken up by the flexible element is relatively large.

16. Device as claimed in any of the foregoing claims, wherein a gripper arm is configured to position at least one flexible element, preferably a row of flexible elements, a short distance adjacently of the object.

17. Device as claimed in claim 16, wherein the flexible element is configured to expand over at least said distance when filled with medium.

18. Device as claimed in any of the foregoing claims, wherein the medium is a fluid, particularly air, more particularly compressed air.

19. Device as claimed in any of the foregoing claims, wherein a flexible element comprises a flexible balloon with a relatively stiff pusher plate arranged thereon.

20. Method for transporting objects in a device as claimed in any of the foregoing claims, the method comprising of:

- displacing one or more gripper arms from respective transport positions, in which an object can be transported, to gripping positions in which an object can be grasped;

- expanding one or more of the flexible elements in at least one direction for the purpose of fixedly clamping the object for transporting;

- displacing gripper arms from the respective gripping positions to the transport positions;

- transporting the objects in a transport direction.

21. Method as claimed in claim 20, wherein expanding one or more of the flexible elements from a release position to a gripping position comprises of filling thereof with medium.

22. Method as claimed in claim 21, wherein the displacement of the one or more flexible elements from the gripping position to the release position comprises of removing medium from the one or more flexible elements.

23. Method as claimed in any of the claims 20-22, wherein the expanding of one or more of the flexible elements comprises of pressing the flexible element inward with an actuator.

24. Method as claimed in any of the claims 20-23, comprising of:

- displacing a first gripper arm from a transport position to a gripping position in which the gripper arm is arranged at a first distance along one side of the object;

- displacing a second gripper arm from a transport position to a gripping position in which the gripper arm is arranged at a second distance along an opposite side of the object;

- expanding one or more of the flexible elements in the first gripper arm over at least the first distance in the direction of the second gripper arm and expanding one or more of the flexible elements in the second gripper arm over at least the second distance in the direction of the first gripper arm for the purpose of fixedly clamping the object;

- displacing gripper arms from the respective gripping positions to the transport positions;

- transporting the objects in a transport direction.

25. Method as claimed in any of the claims 20-24, comprising of returning the flexible element to the uncompressed state in order to release the object.

Description:
DEVICE AND METHOD FOR TRANSPORTING OBJECTS

The invention relates to a device and method for transporting objects. The invention relates particularly to a device and method for gripping and transporting objects from a storage area and/or for transporting and placing objects in a storage area.

Numerous systems are known for taking up objects from a storage rack, for instance objects such as boxes placed at a storage area level, and subsequent transport thereof. Some of these systems make use of rotatable fingers with which the objects can be fixedly grasped or hooked. A drawback of using fingers is that many fingers are necessary which engage on either side of the object and that these are placed at fixed positions to be able to hold the object sufficiently firmly and then displace the object, for instance from the storage position in the storage area to a transport position in the passageway between adjacent storage areas or aisles. Not only does this require a complex construction, it also requires the object being engaged over a relatively large contact area. This limits the transport options of the system. A further drawback is that the objects have to be positioned with a mutual spacing adjacently of and/or one behind another in the storage area in order to provide the fingers with sufficient capability and space to grasp and displace the objects.

It is an object of the invention to provide a device and method of the type(s) stated in the preamble, wherein the above-mentioned and/or other drawbacks of the prior art are obviated.

This object is achieved in a device for transporting objects, comprising:

- a frame on which is arranged at least one gripper arm displaceable relative to the frame, wherein the gripper arm is provided with at least one flexible unit comprising:

- at least one flexible element for filling with medium and expandable in at least one direction;

- an expanding unit configured to expand the expandable flexible element in said direction for the purpose of grasping the object;

- a displacing unit for displacing the at least one gripper arm between at least one transport position, in which at least one object can be transported, and a gripping position in which at least one object can be grasped.

The expanding unit can expand the flexible element, for instance by arranging (more) medium, such as a liquid, gas, gel or the like, in the member and/or by pressing the flexible element inward (for instance with an actuator such as a lifting cylinder). The flexible element will then begin to protrude in a determined direction relative to the original form thereof, so that the flexible element is pressed (directly or indirectly) against an object. The expanding unit can likewise be configured to (once again) return the expandable flexible element to the uncompressed state, for instance by discharging medium from the member and/or by ending the inward pressing of the flexible element.

The flexible element can be embodied such that the flexible element (for instance by feeding and discharging medium) can be arranged between a release position, in which the volume taken up by the flexible element is relatively small, and a clamping position in which the volume taken up by the flexible element is relatively large. In the case an actuator is used, the volume need not of course change. What is important is that a determined side of the flexible element begins to bulge or protrude in a determined desired direction so that this side is pressed against an object in the gripping position.

The flexible element is configured to enable the intermediate space between an object and the gripper arm to be bridged when the medium feed unit expands this element from a release position to a gripping position. The flexible element then exerts a predetermined pressure force on the object so that the object can be fixedly clamped. This fixed clamping can take place by pressing the object against an optionally stationary surface, such as a platform, but can also be realized by pressing the object against an opposite second gripper arm. This gripper arm can itself optionally be provided with one or more flexible elements. According to embodiments of the invention, the device therefore comprises a first gripper arm and second gripper arm arranged on the frame, wherein the first and second gripper arms extend substantially parallel relative to each other and wherein at least one of the gripper arms is provided with at least one flexible element which is arranged so as to be expandable in the direction of the opposite gripper arm.

In determined embodiments the device comprises a first gripper arm and second gripper arm arranged on the frame, wherein the first and second gripper arms extend substantially parallel relative to each other and wherein the two gripper arms are provided with one or more flexible elements which are arranged so as to be expanded in the direction of the opposite gripper arm in order to fixedly clamp one or more objects therebetween. In these embodiments the objects can thus be clamped between the flexible elements of opposite gripper arms.

The flexible element comprises a medium chamber for filling with medium, wherein at least one wall of the medium chamber, in particular the wall of a flexible balloon, is manufactured from one or more flexible materials, in particular elastic materials.

In determined embodiments the flexible element can comprise a medium chamber for filling with medium. The medium chamber has one or more walls here and at least one of these walls is wholly or partially manufactured from flexible material. The flexible material can for instance be formed by an elastic or stretchable membrane. In the case the medium chamber comprises a balloon, the wall of the balloon can be manufactured from flexible material, in particular from elastic or stretchable material. The flexible material can consist here of one material layer, although embodiments with two or more layers are also possible. The wall can further be constructed from a single material or from two or more different materials. In a further embodiment a relatively thick and resilient layer, for instance of foam-like material, can be arranged behind a flexible layer, for instance a rubber layer. The resilient layer and the flexible layer together form a "cushion" with which the objects can be grasped.

The membrane can be inflated by feeding sufficient medium into the medium chamber, while the membrane can also be brought into a flat state when sufficient medium is discharged from the medium chamber. The membrane is preferably somewhat elastic and is arranged in an opening provided in the medium chamber. As a result of the elastic properties the membrane preferably returns automatically from the expanded state to the initial state in which the membrane is substantially flat.

As set forth above, the membrane can be assembled from two or more different materials, for instance from two or more elastic materials. The membrane can for instance comprise a combination of one or more rubber layers (for instance of natural rubber), optionally provided with a foam layer. The foam layer can be provided on the outer side of the membrane (i.e. on the side facing toward the object to be picked up) as well as on the inner side of the membrane and can have a positive effect on the holding characteristics of the device. The thickness of the foam layer is generally greater than that of the other flexible layers, so that the foam layer forms a type of cushion with which the objects can be grasped.

The medium can be discharged by being allowed to flow away, for instance under the influence of gravitational force and/or in that the membrane tends to move back automatically to the flat position. As alternative or in addition thereto, a medium discharge unit can be provided which is configured to discharge medium from one or more flexible elements in order to bring the flexible element from the gripping position to the release position. The medium discharge unit can be configured to create a forced medium flow. An advantage is that the medium chamber can in this way be emptied relatively quickly. This enhances the processing speed during pick-up and transport of the objects. The medium feed unit and medium discharge unit can be separate here, although an integrated version, for instance in the form of a compressor suitable for the purpose, is also possible. A vacuum space can for instance be used for this purpose, although other ways of discharging the medium from the chamber of the flexible element are of course also possible.

As alternative or in addition to the option of feeding or discharging medium to and from the flexible element, the medium chamber is formed in determined embodiments by a flexible balloon for filling with medium. This balloon is preferably at least partially manufactured from flexible material (i.e. a single material or a combination of materials as set forth above) in order to allow the member to expand, for instance by arranging more medium in the member and/or by pressing the balloon inward on one side, and to allow it to return to the non-expanded state, for instance by discharging medium from the member and/or by ending the inward pressing.

In embodiments of the invention a gripper arm comprises: - an elongate support part arranged slidably along the frame;

- at least one row of flexible elements arranged in the support part.

The flexible elements are preferably arranged mutually in line. In further embodiments the device comprises two or more rows of flexible elements arranged above and/or adjacently of each other. In determined embodiments these elements can be selected per group (for instance per row or per part of a row) or in further embodiments even individually (by a correct control of valve mechanisms and the like). This makes it possible to adjust as desired the extent to which an object is engaged, for instance depending on the shape or dimensions of the object.

In embodiments of the invention the support part has a flat component. The flexible element can then be arranged between a release position, in which the flexible element is substantially flush with the flat component, and a gripping position in which the flexible element protrudes relative to the fiat component due to expansion.

Tn further embodiments of the invention the transport device comprises two or more flexible elements arranged in a gripper arm and a control unit for controlling the medium feed unit, preferably also for controlling a medium discharge unit (to the extent this is present). The control unit and the flexible elements can be configured here to selectively expand the flexible elements. The control unit can for instance be configured to expand a first number of the flexible elements of a gripper arm and to hold a first number of the flexible elements of the gripper arm in flat state.

The transport device can be embodied to perform substantially synchronously the bringing of flexible elements of different gripper arms provided at mutually opposite positions to an expanded state or a flat state. This means that an object is engaged (roughly) simultaneously on several sides so that the object can be clamped fixedly in stable manner without the position of the object changing.

A or both gripper arms can be configured to position at least one flexible element, preferably a row of flexible elements, a short distance adjacently of the object. The distance is preferably as small as 5 cm or less, preferably 2 cm or less. At least said distance is then preferably bridged when the flexible element expands.

In determined embodiments a flexible element comprises a flexible balloon with a relatively stiff pusher plate arranged thereon. This pusher plate can be manufactured from metal or other suitable material and on the side facing toward the object the pusher plate can optionally be provided with material with a high coefficient of friction (friction material, for instance - though not limited thereto - the same material of which the balloon itself consists). The balloon is now in indirect contact with the object, i.e. via the pusher plate. The balloon as it were functions here as a means for displacing the pusher plate from a release position and a gripping position and vice versa. This embodiment can take a compact form and for instance makes it possible to impart determined desired properties (high wear resistance and so on) to the part which makes frequent contact with the object. The grip on the object can further be maintained or even improved.

Provided according to another aspect of the invention is a method for transporting objects in a device as defined herein, the method comprising of:

- displacing one or more gripper arms from respective transport positions, in which an object can be transported, to gripping positions in which an object can be grasped;

- expanding one or more of the flexible elements in at least one direction for the purpose of fixedly clamping the object for transporting;

- displacing gripper arms from the respective gripping positions to the transport positions;

- transporting the objects in a transport direction.

Expanding one or more of the flexible elements from a release position to a gripping position can for instance comprise of filling thereof with medium, while the displacement of the one or more flexible elements from the gripping position to the release position can comprise of removing at least a part of the medium from the one or more flexible elements. Tn another embodiment the expanding of one or more of the flexible elements comprises of pressing the flexible element inward with an actuator. When a flexible element mounted in an arm is for instance pressed inward on one side, another side of the flexible element will tend to begin bulging outward (if medium is unable to flow away). This latter side can then be pushed (directly or indirectly) against an object in order to grasp this object.

In further embodiments the method comprises of:

- displacing a first gripper arm from a transport position to a gripping position in which the gripper arm is arranged at a first distance along one side of the object;

- displacing a second gripper arm from a transport position to a gripping position in which the gripper arm is arranged at a second distance along an opposite side of the object;

- expanding one or more of the flexible elements in the first gripper arm over at least the first distance in the direction of the second gripper arm and expanding one or more of the flexible elements in the second gripper arm over at least the second distance in the direction of the first gripper arm for the purpose of fixedly clamping the object;

- displacing gripper arms from the respective gripping positions to the transport positions;

- tr ansporting the objects in a transport direction.

Once the objects have arrived at their destination, the aims are displaced once again so that the objects are placed at a correct position above the surface. The flexible element is then returned to the uncompressed state so that the object is released.

Further advantages, features and details of the present invention will be elucidated on the basis of the following description of several embodiments thereof. Reference is made in the description to the accompanying figures 1-18, which show an embodiment of the device and method according to the invention. Figure 1 is a schematic view of a storage area provided with an embodiment of the transport device according to the invention;

Figure 2 is a perspective side view of a first embodiment of the invention in which the frame has wheels with which it can be displaced along the storage areas;

Figures 3 and 4 show respectively a front and a side view of the embodiment of figure 2;

Figures 5A and 5B are partially cut-away perspective views of a second embodiment of the invention (in which the frame can be placed on a separate transport unit for displacement thereof along the storage areas) in respectively a central position (transport position) and a gripping position (extended position);

Figure 6 is a perspective view of an embodiment of a gripper arm according to the invention;

Figures 6A-6C show respective perspective views of the embodiment of figures 5A-5C for simultaneous transport of a number of products;

Figures 7A-7C show respective schematic views of the embodiment of figures 5A, 5B for placing the objects from the transport device onto an outfeed conveyor;

Figures 8A-8C show respective schematic views of the embodiment of figure 5 for feeding products into the transport device;

Figures 9A-9D show respective top views of different transport devices suitable for handling one, two or more rows of products;

Figures 1 OA- IOC show respective top views of conveyors suitable for transporting products of different shapes;

Figures 1 lA-11C show respective views of random examples of objects to be transported with the transport device according to the embodiment of the invention;

Figure 12 is a side view of a transport device according to an embodiment of the invention, suitable for transporting one or more randomly selected objects from a number of rows of stacked objects;

Figures 13A and 13B show respective side views of a height-adjustable embodiment of the invention in a lower position and in an upper position;

Figures 14A-14B show respective perspective side views of a further embodiment of the invention;

Figures 15A-15B show respectively a front view and a side view of an embodiment of the invention, wherein use is made of only a single arm for the purpose of grasping objects;

Figures 16A-B show respectively a front view and a perspective side view of a storage rack with an object, and figure 16C shows a side view of the storage rack of figures 16A, 16B in combination with a further embodiment of the invention;

Figures 17A and 17B show respective front views of a further embodiment of the invention wherein use is made of indirect gripper fingers;

Figure 18 is a perspective view of a further embodiment of a gripper arm according to the invention;

Figures 19A and 19B show views of a further embodiment in which use is made of a friction plate, in respectively the transport position and the gripping position; and

Figure 20 is a partially cut-away perspective detail view of a further embodiment of a gripper arm according to the invention in which the flexible elements can be individually operated.

The figures show different embodiments of the transport device (also referred to here as the load receiving means) according to the invention. The transport device is able to grip objects by means of a controller (for instance a PLC, computer or microprocessor) by fixedly clamping and then shifting these objects further into a desired position. A load receiving means can be mounted on another machine, such as a warehouse crane, or can have its own drive so as to thus be able to move in random other directions. This may for instance only be possible in a horizontal direction of for instance a storage area, but also in combination with a vertical direction. Reference is then made here to respectively a shuttle and a warehouse crane. In the case of a shuttle only a single level (height) is served (i.e. the objects are located in a part of the storage area situated at a determined height), unless the shuttle can be placed in another part of the storage area situated higher or lower or the shuttle can serve one or more further levels by means of a built-in vertical displacement option. Reference can in this case also be made to a load receiving means with its own internally integrated travel displacement, i.e. a shuttle. In the case of a warehouse crane the load receiving means is placed on the warehouse crane and integrated into the control thereof in simple manner.

In a determined embodiment the device can comprise a number of different modules, such as a number of gripper units provided with gripper arms, a movable frame (also referred to here as the load carrier), a width adjustment and so on. The gripper arms each comprise an extending element comprising a number of flexible units. These flexible units comprise a space or chamber which is sealed with a flexible element, for instance an optionally elastic membrane, in which a greater or lesser amount of medium, such as compressed air, gel, oil and the like, can be arranged as desired in order to fill up the flexible element as a balloon. The flexible elements will then expand, whereby an object located a determined distance from the gripper arm will be subjected to a determined pressure force. If an arm is then extended on either side of an object and the predetermined flexible unit or units are then filled with a medium, this object is therefore enclosed and clamped by the filled flexible units on either side. The object can then be shifted using the displacing arms. The flexible units can transmit a high pressing force to the object such that the object remains fixed in all directions as a result of the friction force occurring between the object and the flexible elements. The object is for instance thus prevented from falling downward under the influence of gravitational force, even when in such a situation the object is not further supported. When the flexible units are 'deflated' again following the shifting, the clamping process as such is at an end and the displacement of the object has been realized.

Using these arms with flexible units it is thus possible to grip and then displace, for instance lift and/or shift, an object such as a cardboard box or a plastic container which is for instance located on a shelf in a rack of a storage area, so that this object is shifted inward (for instance to a transport position in the passageway between the storage racks). The transport device can then be transported, for instance in order to shift the object away again at another longitudinal position. Said movement is after all also possible in reverse in order to shift an object off the load receiving means onto a carrier located outside these means and to subsequently 'deflate' the flexible units.

The arms are preferably embodied as extendable mechanical carriers with a high stiffness and stability which can be shifted at any desired distance lying within the range of the mechanism. The design preferably takes an essentially symmetrical form. Owing to such a symmetrical design the above applies for both sides, for instance both the left and right-hand side and/or both the upper and underside of the load receiving means. The flexible units, a predetermined number of which is arranged on each gripper arm, can consist in determined embodiments of a very flexible material which is also to a large extent wear-resistant and/or has a high coefficient of friction. The material of the membrane can be clamped between a base plate and a so-called membrane plate. Examples of such a construction are shown in figures 6 and 18.

This membrane plate has a predetermined number of recesses which also defines the shape of the flexible elements. This shape can be random, such as round, rectangular or triangular. The chosen shape can depend on the dimensions, shape and/or the nature of objects which have to be 'gripped' using these flexible units. In determined embodiments all flexible elements per gripper arm are operated simultaneously. In other embodiments an individual operation (so each flexible element individually) or a group operation (for instance some of the flexible elements of a determined gripper arm) is realized. Which of the arranged flexible units are filled can be selectively determined in specific embodiments. This depends for instance on what is programmed in the controller.

The flexible units can be filled with medium (particularly a fluid, i.e. a liquid and/or a gas such as compressed air). The quantity of medium is partially determined by the objects which have to be 'gripped'. Other media are however also possible. Larger and heavier objects having a hard and compact form and shell can withstand somewhat more pressure than for instance light and fragile objects. The filling pressure caused by the filling medium can therefore be modified hereto.

The movable frame (also referred to here as the load carrier) can take different forms. The frame is provided with a placing surface, for instance a placing plate and/or one or more placing conveyors. An example of a placing conveyor is a belt conveyor. In the case of a placing conveyor, for instance a two-fold belt conveyor, there is the advantage that the aims generally travel smaller distances because a gripped object is pulled further on board and can be positioned inside the load receiving means by the belt conveyor. During transport of the objects to the outfeed the arms can also remain in the rest position and the placing conveyor provides for the transport, in any case during pick-up of the objects.

There is generally more flexibility on board in the case of a placing conveyor than in the case of a carrying plate (i.e. a placing plate). The arms will have to move more when a placing plate is arranged. So-called sliding along is then one of the options. When an object is taken on board from the left-hand side and the object lies on the left-hand side of the carrying plate after the first movement of the arm, it is possible using the arm to shift the object to the right-hand side of the carrying plate. This takes time of course, which is generally undesirable.

Another option is to extend the arm what is really too far to the left, to grip the object with the flexible units on the right-hand side of the arm and to subsequently pull the object on board such that it is positioned directly on the right-hand side of the carrying plate. The time required to shift the arm is then somewhat longer, but a second shifting movement need no longer be performed. The cycle time can hereby be significantly shorter than in the case of the slide -along method.

This particular movement is possible in that, at least in determined embodiments of the invention, the objects are gripped on the side and no shape -dependent hooking method is actually used.

A further technical feature is that the objects in the rack, on the feed conveyors and on the transport device require only little specific intermediate spacing, or none at all. In prior art systems wherein the objects are hooked and pulled by so-called pivotable fingers, this intermediate spacing is of essential importance. In embodiments according to the present invention the objects are clamped fixedly on the outer side, whereby the objects can be handled without intermediate spacing and can simply lie against each other. Not only does this provide many advantages in the storage of the objects in that many more objects can be stored in the available space, in loading of the storage area the movements are also less complicated and more objects can be carried along per movement.

The width adjustment is a module which can optionally be built in. This width adjustment can adjust the intermediate distance (i.e. the width) between the gripper arms, depending for instance on the dimensions of the object. The width adjustment can operate symmetrically relative to the centre of the load receiving means. Another form consists of one arm taking a static form and the other arm being moved by means of the width adjustment. The control and positioning of the transport device can in this case then be said to be variable relative to a fixed point on the transport device.

The width adjustment can be driven, for instance by means of a stepping motor, wherein the transmission of the movement of the arm(s) can be performed using a chain, toothed belt, gear rack or screw spindle. The arms are then provided with a straight guide constructed on the frame.

The frame of the machine forms the actual surface on which more or fewer modules can be mounted. It is not important whether modules are mounted and/or omitted, the frame remains identical in determined embodiments of the invention. The frame is constructed from lightweight profiles and can optionally also consist of a module constructed from carbon fibre.

Figure 1 shows a schematic representation of an arrangement in which an embodiment of a transport device according to the invention is incorporated. The figure shows a storage area 1 consisting of two rows of parallel storage racks 3, 3' with an elongate passageway 9 therebetween. Each of the storage racks 3, 3' is constructed from a number of beams and uprights 2 between which a number of platforms (shelves or platforms) 4 is arranged. Rows of objects (O) are placed on these platforms 4. One or more transport devices 10 according to embodiments of the invention can be disposed in passageway 9 between the two storage racks 3, 3'. The figure shows a single transport device (for instance the above stated shuttle) for processing objects on the lower platforms 4 of the storage racks, although broken lines show that more transport devices 10' can also be disposed. Transport devices 10, 10' can function independently of each other, controlled by a central control unit (not shown). In other embodiments use is made of a machine (for instance the above-mentioned warehouse crane) which is provided with two or more of the transport devices described herein for picking up and setting down objects at more than one height position and/or at more than one longitudinal position (in the transport direction).

Transport device 10 can displace in a transport direction along passageway 9 between storage racks 3, 3' using a drive provided in the transport device. Referring to figure 2, transport device 10 is disposed on four transport wheels 7 (trolley). Transport wheels 7 can rest on rails 8 arranged on the side of uprights 2. Driving one or more of said transport wheels 7 with an electric motor mounted on the frame allows the frame to be displaced along the storage rack. The power supply to the electric motor can be realized by a sliding contact provided on the underside of the frame. The sliding contact can be dragged over a current-carrying rail arranged along one or more of the storage racks. Other ways of supplying power to the electric motor are also possible. One or more batteries mounted on the frame can for instance be provided, or use can be made of contactless energy transfer by means of induction.

Transport device 10 is further configured to pick up and/or place random objects (O) respectively from and at random positions along the passageway. In the shown embodiment the transport device is suitable for processing objects arranged on shelves of equal height, but in other embodiments (not shown in this figure) transport device 10 or a part thereof is also displaceable in height direction so that objects on platforms at other heights can also be picked up or placed.

Referring to figures 2-8, the construction and operation of a first embodiment of the transport device will be further elucidated. Figure 2 shows a perspective side view of transport device 10, comprising an elongate frame 11 on which a first gripper unit 12 and a second gripper unit 13 are arranged. The two gripper units have substantially the same structure, and for the sake of clarity and simplicity of the description the construction and operation of only one of the gripper units 12, 13 will be described.

Referring to figure 3, a gripper unit 12, 13 is arranged via two supports 24 on frame 11. Provided in supports 24 are mounting elements 25 which can be arranged in corresponding openings 26 in frame 11 in order to displace supports 24 and the gripper units 12, 13 connected thereto in the direction Pj such that they come to lie at a suitable mutual distance (distance t in figure 3). A width adjustment for the gripper units is in fact hereby realized.

Tn the shown embodiment the gripper units 12, 1 can be shifted manually until a mutual distance (t) suitable for a determined type of object has been reached. In other embodiments the mutual distance can be adjusted as desired via one or more electric motors, optionally controlled by a control unit present in device 10 and/or the above-mentioned central control unit.

Each gripper unit 12, 13 comprises a housing 15 inside which a lying frame part 18 (figure 5A) is arranged. Respective gripper arms 22, 23 are arranged on the lying frame part 18 of gripper units 12, 13. Referring to figure 5 A, gripper arm 22 of the first gripper unit 12 and/or gripper arm 23 of the second gripper unit 13 can be displaced reciprocally in the transverse direction (direction P 2 ), for instance from the central position shown in figure 5A to an extended position shown in figure 5B.

Each of the gripper arms 22, 23 is more particularly displaceable in transverse direction (P 2 ) using electric motor 16 and a transmission mechanism (not shown in detail). In determined embodiments gripper arm 22, 23 is displaceable from the central position (as shown in figure 5A, in which the gripper arms are situated substantially wholly inside transport device 10) to a first extreme position (as shown in figure 5B) in which the gripper arms are displaceable to a position wholly extended in one direction. The positions of the gripper arms shown in figure 5A and figure 5B are referred to as the central position and the gripping position. In determined embodiments the gripper arms are displaceable in only one direction from the transport position to the gripping position. In other embodiments the gripper arms can be displaced to both sides, i.e. from the transport position to the left-hand gripping position and from the transport position to a right-hand gripping position.

As shown in more detail in figure 6, a gripper arm 22, 23 comprises an upright fiat support part 31 (also referred to here as the wall or the base plate), on one side of which two rails 32, 33 are arranged. These rails can be guided along corresponding rails 27, 28 in the lying frame part 18. Rails 32, 33 can be guided in respective receiving profiles 90 (see also figure 20) of a carriage 91, while rails 27, 28 are arranged in respective receiving profiles 92. Relative displacement of gripper arm 22, 23 and the lying frame part 18 takes place by driving a gear wheel (not shown) which engages on a rack 94 arranged on support part 31. An elongate membrane plate 34 in which a (single) row of substantially elongate openings 35 is arranged is further provided on the opposite side of gripper arm 22, 23. Provided in these openings are flexible elements 36, for instance flexible membranes, in particular inflatable balloons. Figure 6 shows that a number of the flexible elements 36 extend substantially flush relative to plate 34 (release position), while two flexible elements 36' are inflated and protrude inward relative to the visible side of plate 34 (gripping position). An elongate passage (pipe, duct) is arranged on the rear side of the plate. This passage carries the medium to each of the flexible elements and can in turn also discharge the medium therefrom. In determined embodiments all flexible elements are operated simultaneously. In other embodiments an individual operation is realized.

Figure 20 shows a further embodiment of a gripper arm according to the invention. This embodiment largely corresponds to the above described embodiment, and a detailed description is dispensed with here. The figure shows a number of successively placed modules 95, 95' mounted on support part 31. In mounted position the modules form an elongate, continuous passage or tank for the feed (and/or discharge) of medium to and from the individual flexible elements. A medium feed can be connected to this passage or tank so that the tank can be filled with medium. The medium feed can for instance be realized by a feed hose which is connected on one side to the passage or tank on the movable arm and on the other side to a medium source which is arranged on the frame of the device (and so does not co-displace with the movable arm). In a determined embodiment the feed hose is arranged in a protective element, for instance a drag chain or similar element, so that it remains protected during use but still enables a relative displacement of the arm and the frame. In this protective element can also be arranged power cables which are connected to a control unit on the frame and to one or more of the valves to be described below which regulate access to the individual medium chambers.

Referring to figure 20, each of the modules 95, 95' is associated with a single flexible element. In the shown embodiment each of the modules 95 is provided with one or more valves remotely controllable via the electricity cables by a central control unit. These valves are shown schematically in the figure with reference numeral 96, 96'. These valves are individually controllable, for instance by said control unit, and can be opened and closed such that a dosed supply of medium to the associated flexible element (and optionally also discharge from the flexible element) can be realized.

In the above described embodiment the modules associated with one or more expanding units together form a single passage or tank which can be filled with medium using a single feed. The individual operation of the expanding units takes place here with the valves provided on the movable arm. In other embodiments a number of feed conduits is however provided, wherein each of the feed conduits is connected to a single expanding unit. The feed conduits can be guided from a source provided on the frame via the protective unit and to the different expanding units. Valves for operating the individual conduits are situated in this embodiment on the frame itself and can optionally be controlled by the control unit.

Each of the flexible elements is connected via medium feed and discharge channels and/or conduits to a medium feed unit, for instance a compressor, with which medium (for instance liquid and/or gas, such as air) can be supplied. In determined embodiments each of the flexible elements is further provided with a selectively controllable valve mechanism with which access to a medium chamber behind the associated flexible element can be regulated.

In determined embodiments of the invention the feed of medium (fluid) is regulated such that all flexible elements 36 are simultaneously filled to substantially the same degree with fluid. Tn other embodiments it is however possible to control each of the flexible elements 36, 36' individually and/or to individually control groups of a number of random flexible elements. It is also possible to fill one or more preselected flexible units to a degree differing from that of one or more of the other flexible units. It is thus possible for instance to make the degree of filling of the medium chambers behind the different flexible elements dependent on the shape and/or dimensions of the objects for gripping so as to thus enable an optimal engagement of the objects.

In order to make an inflated flexible element flat again, a discharge channel connected to the associated medium chamber can be opened, for instance by operating a valve mechanism. The air is then discharged so that after a time the flexible element will return to its flat initial state. In determined embodiments the medium (for instance air) flows out of the medium chamber without further assistance. As alternative or in addition to such a free discharge of medium, the medium can also be discharged forcibly, for instance by actively suctioning the medium out of the medium chamber (for instance using a vacuum). An advantage hereof is that the switching speed between the inflated position (gripping position) and the starting position can be increased.

As shown in figures 5A, 5B the above-mentioned flexible elements or membranes 36 of first gripper arm 22 and second gripper arm 23 are directed toward each other. The different membranes of the gripper aims are preferably situated here at the same height position and/or transverse position so that objects can be held substantially symmetrically. In other embodiments however, these positions differ to greater or lesser extent.

Figure 5B shows for instance that in order to pick up an object (O) on the front part of the side of the object, it suffices to activate a limited number of flexible elements (in the shown situation two) by filling the associated medium chambers with medium (fluid). Owing to the pressure of the membranes against the sides of the object it can be firmly held by arms 22, 23. Once held fixedly by the arms, the object can be transported by moving the aims back from the extended position (figure 5B) to the central position (figure 5A).

When the object has been moved by displacing the arms to the central position, it can be set down on a placing surface of the device. Setting down takes place by deflating the medium chambers so that the flexible elements return to their initial position and the object tends to displace downward under the influence of gravitational force. The placing surface can take different forms.

Shown in figure 2 is an embodiment wherein a flat positioning element 5, for instance a flat plate, is arranged on top of frame 11 between gripper units 12, 13. The objects can be disposed on this flat placing plate 5. In the embodiment shown in figures 5A, 5B flat placing conveyors are provided instead of a flat placing plate 5. Transport device 10 more particularly comprises a first placing conveyor 20 and second placing conveyor 21. Each of the placing conveyors 20, 21 can displace objects disposed thereon in transverse directions (direction P 3 , P 4 respectively). Tn the shown embodiment the placing conveyors are constructed from endless conveyor belts which can be set into motion using a drive (not shown). In other embodiments other placing conveyors are provided, or there is only a single placing conveyor.

Figures 7A-7C show different examples for placing an object O from the transport device onto a further discharge conveyor for further processing thereof. Figure 7A shows transport device 10 according to the embodiment shown in figure 5A. Transport device 10 is arranged adjacently of an outfeed conveyor 40. This outfeed conveyor can for instance be of the endless conveyor type, although other types of conveyor are also possible. The outfeed conveyor can for instance be placed at the end of the passageway between the two rows of storage areas of figure 1. A pivotable flipper 41 provided on the side of conveyor 10 is first of all pivoted from an upward directed position (closing position) to a lying one (release position). When flipper 41 is in the release position, it no longer impedes sliding of the objects off transport device 10. Through operation of the second placing conveyor 21 and outfeed conveyor 40 the objects can now come to lie via the lowered flipper on outfeed conveyor 40, as shown in figure 7B. The flipper can then be pivoted back to the closing position, and device 10 is ready for further use. Figure 7C shows the situation in which the objects are not arranged on outfeed conveyor 40 with placing conveyor 21 but are carried onto outfeed conveyor 40 by extending the arms 22, 23. A placing conveyor 21 need not therefore be present in the device in this embodiment. An advantage of the embodiment shown in figure 7C is that outfeed conveyor 40 need not be running in order to still arrange objects O thereon in controlled manner.

Figures 8A-8C show in similar manner how objects can be placed from a feed conveyor 49 onto a placing surface of the device. This is possible by having the feed conveyor continue running and transport the objects in the direction of the device until the arms are able to take hold of and carry the objects (figure 8B) to the placing surface. The arms then displace the objects to the placing surface. By driving one or more of the placing conveyors it is finally possible to provide for a correct positioning of the objects on the placing surface, for instance by having the right-hand placing conveyor (in figure 8C) transport the objects to the right until the foremost object has been pushed against the flipper (in the closing position).

Figures 6A-6C show an example in which a number of objects can be removed simultaneously from platform 4 of a storage rack. In this example arms 22, 23 are extended from the central position shown in figure 6A (transport position) to the gripping position shown in figure 6B. By now filling a greater number of membranes than in the example of figure 6 with fluid, the whole row of objects (O) can be firmly grasped by the arms. Once the objects have been grasped in this manner, the arms return to the transport position, as shown in figure 6C. In this example the objects slide with their underside over platform 4 before they are received by the first placing conveyor 20. The objects can also be displaced relative to this placing conveyor 20 when the surface of the placing conveyor is sufficiently smooth. In other embodiments placing conveyor 20 is switched on and the upper surface thereof is displaced substantially synchronously with the gripper arms, so that both the gripper arms and placing conveyor 20 can slide the objects inward. It is however also possible to first lift and then displace the objects inward without contact occurring between the underside of the objects and the transport device. This has the advantage that the objects need not slide over the surface. Figures 13A-13B show an embodiment in which arms 22, 23 of the transport device are displaceable in upward direction (P 6 ). Starting in the gripping position (figure 13A), the membranes of the gripper arms are inflated so that the objects are firmly grasped from the sides. Gripper arms 22, 23 are then displaced upward, for instance by moving the whole of the gripper units 12, 13 upward into the position shown in figure 13B. The underside of the objects is now situated at some distance relative to the upper side of platform 4 of the storage area. The arms can then be retracted again in the usual manner from the gripping position in figure 13B to the transport position.

Figures 13A and 13B further illustrate how a product (0 2 ) positioned in the centre of a row can be removed from the row. The gripper arms are first of all placed adjacently of product (¾. Only the membranes positioned at the location of product O 2 are then filled with fluid, while other membranes remain unfilled (and thus flat). Product O 2 is hereby picked up, while products Oi and O 3 remain unengaged (product Oi because the gripper arms have not yet arrived there and product O 3 because the membranes there are not filled). Object O 2 can be removed from the row by now displacing the whole of the gripper arms or (as shown here) the whole transport device 10 upward (direction P 6 ).

Figures 9A-9D show different configurations with which objects can be picked up from a storage area or placed therein. Figure 9 A shows the situation in which a single row of objects is handled by transport device 10. In this embodiment gripper units 12, 13 ar e placed relatively close together, i.e. the intermediate distance (t) (figure 3) is relatively small. From the conveyor belt shown in figure 9 A the whole row of objects can be displaced outward in one operation via the arms to the gripping position shown in figure 9B. Figure 9C shows the situation in which two rows of objects are handled. Despite the absence of support on the underside, the objects O can still be displaced in stable manner to the position shown in figure 9C by having the two arms 22, 23 exert sufficient pressing force on the objects. Figure 9D shows the situation in which three rows of products can even be displaced while pressed firmly together from the central position to the gripping position. This means that large numbers of products can be picked up from or placed in a storage area in one operation. Depending on, among other factors, the embodiment of the transport device, the shape and dimensions of the objects and the pressing force to be produced by the flexible elements, the number of mutually adjacent rows of objects can be even greater than in the outlined examples.

Figures 1 OA- IOC show that the objects can have different shapes and dimensions. In figure 10A the objects are formed by cylindrical containers, in figure 10B by hexagonal containers, in figure IOC by containers of even further differing shape. All stated shapes can be processed with the same transport device, often without any change in the construction being necessary. In many cases a suitable adjustment of the quantity of medium in the medium chambers (i.e. the extent of the pressing force of the gripper arms) and/or a correct selection of the flexible elements which do and do not have to be inflated will already suffice to enable a reliable processing of objects of different shape/dimensions.

Figures 1 lA-11C further show that the objects need not always have equal dimensions in the height. Shown for instance in figure 11 A is a tapering container with cover. With a correct degree of inflation of the membranes the downward tapering form of figure 11A can also be f irmly grasped with the gripper arms. The same applies for the tapering form of figure 1 IB or the tray shown in figure 11C. The material from which the objects are manufactured can also vary. Objects with a smooth outer side may for instance require a higher pressing force than objects with a rough outer side. The optimal pressing force for the object shape can be realized by a suitable adjustment of the pressure in the medium chamber. It is not a problem if ribs are for instance arranged on the objects, and the objects can still be held in reliable manner.

Figure 12 shows that the transport device is also suitable for transporting objects which are disposed in a number of rows and wherein each row moreover comprises a number of products (for instance three). The transport device can for instance carry all the objects from the highest level (level 3) at the same time. It is however also possible to take hold of and then lift a single object, so that the object can be removed from the row. It is thus not necessary to always take away the first object encountered by the gripper arm when it is displaced from the central position. The option of also displacing the aims in upward and downward direction makes it possible to take up and remove any random element from a row. It is further possible to take hold of two or more stacked objects simultaneously, depending on the height of the gripper arms. It is for instance possible to take up and remove objects 2A and 3A, while it is also possible to take away a whole stack of objects in one operation.

In an embodiment of the invention membranes 36 have a relatively high friction in the height direction (Y direction) so that the chance of the objects nevertheless still dropping downward under the influence of gravitational force once they have been grasped is relatively small.

It is not the case that transport device 10 need always have at least two movable arms with flexible elements. Shown for instance in figures 14A, 14B is an embodiment in which transport device 60 has only one movable arm 61 with flexible (inflatable) elements. The structure of arm 61 is identical to the above-mentioned arms 22, 23. A movable arm 62 is provided on the opposite side of transport device 60. This movable arm 62 is not provided with flexible elements. Movable arm 62 substantially comprises a flat plate against which the object can come to rest. In the shown embodiment an (optional) friction element 63 is provided. In the shown embodiment this friction element 63 is an elongate addition on the visible side and comprises material with a relatively rough surface. The object can still be grasped quite firmly by now extending arms 61 and 62 and pressing the object via membranes 64 against arm 62.

Figures 15A and 15B show a further embodiment of the invention. This embodiment is only provided with a single slidable arm 67. This slidable arm is provided with flexible elements and has essentially the same construction as the above described extendable arms provided with inflatable flexible elements. Other than in the above shown embodiments, slidable arm 67 is not placed in a upright position but in a lying position. The arm is further arranged such that it can engage on the upper side of an object instead of on the side thereof. No movable arm is provided on the underside. Support is found here in the platform 4 itself and in the placing surface (formed for instance by the placing conveyors 20, 21 or by the above-mentioned fixed plate). Figures 15 A, 15B show that arm 67 can firmly clamp the object through inflation of membranes 68. When the object is held in this manner, the object (O) can be displaced in the direction of placing conveyors 20, 21 of the transport device (direction P 7 ) by retracting the arm 67.

As shown in figure 15B, arm 67 comprises in the relevant embodiment two rows of membranes 68 in order to keep the object stable during gripping and displacing of the arms. It will be apparent to the skilled person that the number of rows of membranes 68 can also be larger or smaller in other embodiments.

Figure 18 shows a cut-away view of a part of an embodiment of a gripper arm which is not provided with a single row of flexible elements 36 but with a double row. In an embodiment of the invention each of these membranes can be operated individually or in a determined group (for instance all upper membranes and all lower membranes). Fairly high objects or objects of greatly varying form can manner for instance in this way be grasped or, in the case of lying instead of upright arms as in the embodiment of figures 15A, 15B, wide objects can be grasped. In the case of for instance a tapering object (figures 11A and 1 IB) it is possible to inflate the membranes in the lower row of the arm more fully than the membranes in the upper row. The object can in this way still be grasped in firm and stable manner despite the differing shape thereof.

Figures 16A-16C show a further embodiment of the invention. In this embodiment storage areas 70 are embodied without platform or shelf. In this embodiment the objects O are only supported by two angled profiles 71, 72 extending on either side of the storage racks. This means that space is available on the underside of object O for taking hold of the object. Use is made hereof in the shown embodiment in that a first gripper arm 73 can engage on the upper side and a second gripper arm 74 can engage on the underside of the object. When membranes 75, 76 of respectively the first and second gripper arm 73, 74 are inflated, the arms engage on respectively the upper side 76 and underside 77 of the object. In the situation shown in figure 16C the object has been grasped on both sides and can be removed from the rack by retracting the two arms 73, 74 (direction P 7 ).

Figures 17A, 17B show a further embodiment of the invention. To the extent components of this embodiment correspond to those of the above described embodiments, a detailed description thereof has been dispensed with. Instead of having the gripper arms engage directly on an object via the membranes, use is made here of an indirect engagement. So-called gripper fingers 81, 82 are provided. Each of the gripper fingers 81, 82 is mounted on an arm via respective hinges 83, 84, i.e. gripper fingers 81 on left arm 22 and gripper fingers 82 on right arm 23. If the gripper fingers are mounted at their lower outer end on the membrane (for instance the balloon), the gripper fingers follow the movement of the membrane. If this is not the case, a mechanical spring (not shown) can ensure that the fingers tend to retract to the open position shown in figure 17 A. In this open position the fingers extend downward so that space remains between the side of the object and each of the fingers. However, when membranes 85, 86 of arms 22, 23 are now inflated, fingers 81, 82 will tilt inward to some extent to the closed position shown in figure 17B. In this position the lower outer ends of fingers 81, 82, which are provided in the shown embodiment with a material 88, 89 specifically embodied for the purpose, press against the sides of the objects. The objects are in this way grasped and can be displaced further. When the chambers behind the membranes deflate and the membranes return to the flat starting position, the fingers return to their open position under the influence of gravitational force. In this embodiment (for which numerous further variants can of course be envisaged) membranes 85, 86 thus provide for an indirect engagement on the objects for grasping, instead of direct contact occurring between the membrane material and the object.

Figures 19A and 19B show an embodiment in which flexible element 97 comprises a flexible balloon 98 with a relatively stiff pusher plate 99 arranged thereon. The pusher plate is provided on the visible side with a rough material 100. The balloon is now in indirect contact with the object, this being understood to mean that balloon 98 does not make direct contact with the object (not shown) but does so via pusher plate 99. The balloon as it were functions here as a means for displacing the pusher plate from a release position, as shown in figure 19 A, to a gripping position as shown in figure 19B.

The present invention is not limited to the above described embodiments, and the rights sought are defined by the following claims, within the scope of which various modifications can be envisaged.