Title:
Loading system for a machining station
Kind Code:
A1


Abstract:
The invention refers, among others, to a loading system for a machining station which machines on work pieces, the loading system having a loading device which interacts with a pallet carrying the work piece. Several swivelling levers are arranged on the loading device in a way that they can be driven. The pallet is held by several swivelling levers on the gripping device.



Inventors:
Grob, Burkhart (Bad Worishofen, DE)
Lutz, Heinrich (Dirlewang, DE)
Application Number:
10/861509
Publication Date:
07/28/2005
Filing Date:
06/07/2004
Assignee:
GROB BURKHART
LUTZ HEINRICH
Primary Class:
International Classes:
B23Q7/03; B23Q7/04; B23Q7/14; (IPC1-7): B65H1/00
View Patent Images:



Primary Examiner:
HESS, DOUGLAS A
Attorney, Agent or Firm:
JACOBSON, PRICE, HOLMAN, STERN (Washington, DC, US)
Claims:
1. Gripping device serving for gripping goods like work pieces or pallets carrying work pieces, and the gripping device having a gripping drive, which operates swivelling levers in such a way that they engage in a first position in gripping pockets or undercuts of the good in a holding way and that they are swivelled out of them in a second position and release the good in such a way that good and gripping device can move relatively toward each other in one plane.

2. Gripping device according to claim 1, characterised in that the plane is rectangular to a connection line (46) between the good (4) and the gripping device (6).

3. Gripping device according to claim 1, characterised in that the plane is parallel to a contact surface (47) between the good (4) and the gripping device (6).

4. Gripping device according to claim 1, characterised in that the swivelling axis (69) of the swivelling levers is parallel to the plane.

5. Gripping device according to claim 1, characterised in that the good (4) and the gripping device (6) can be moved toward each other without collision.

6. Gripping device according to claim 1, characterized in that the distance of the swivelling levers (60) is smaller than the external dimension of the good (4).

7. Gripping device according to claim 1, characterised in that the swivelling levers (60) interact coming from the same side with the respective gripping pockets (40) and undercuts of the good (4).

8. Gripping device according to claim 1, characterized in that the distance of the swivelling axes (69) of the swivelling levers (60) is smaller than the external dimension of the good (4).

9. Gripping device according to claim 1, characterized in that the gripping device (6) has a contact plate (68) and the external surface of the good (4) sits close to the contact plate (68) in the first position.

10. Gripping device according to claim 1, characterized in that the turning levers (60) are arranged on shafts (62), and the gripping drive (61) drives the shafts (62) in an opposite direction, preferably two swivelling levers (60) being arranged per shaft (62) and two shafts (62) being arranged.

11. Gripping device according to claim 1, characterised in that the swivelling levers (60) are arranged on shafts (62) and the gripping drive (61) has a slider (63) acting on the shafts (62) which is driven via a self-locking gear, in particular a knuckle joint arrangement (64) by a working cylinder, and/or the gripping device (6) is designed self-locking in such a way that the good (4) is not separated from the gripping device even when the gripping drive breaks down.

12. Gripping device according to claim 1, characterised in that the good (4) is supported for the time being on a support (7), in particular a conveying line or the like, and, after the gripping device (6) has taken hold of the good (4), the support (7) and/or the gripping device is moved away.

13. Gripping device according to claim 1, characterised in that, before the gripping device (6) releases the good (4), at least one support (7) for the good (4) is positioned, preferably below the good (4).

14. Gripping device according to claim 1, characterised in that the good (4) is suspended from the gripping device (6) or stands on the gripping device.

15. Gripping device according to claim 1, characterised in that the swivelling levers (60) are swivelled relatively to the good (4), in order to hold the good (4), each time toward the edge of the good, in particular from the inside to the outside.

16. Gripping device according to claim 1, characterised in that the gripping device (6) can be moved by a running carriage (24), in particular with a running carriage drive, in a guide (21).

17. Gripping device according to claim 1, characterised in that the gripping device has a running carriage and the gripping device (6) with the picked up good is located with a running carriage drive below or above the running carriage (24).

18. Gripping device according to claim 1, characterised in that the gripping device has a running carriage and the gripping device (6) projects over the running carriage in particular with the picked up good (4).

19. Gripping device according to claim 1, characterised in that the gripping device (6) is narrower than the good/the pallet (4).

20. Gripping device according to claim 1, characterised in that the gripping device has a running carriage with a running carriage drive and the opening and closing movement of a door (90) closing the machining station is derived from the running carriage drive (20) or from the movement of the running carriage (24).

21. Gripping device according to claim 1, characterised in that the gripping device (6) is part of an elevator or a turntable.

22. Gripping device according to claim 1, characterised in that a pallet carrying the work piece or a work piece is provided as good (4).

23. Good, for example a pallet carrying the work piece or a work piece for interaction with a gripping device, the good having at least gripping pockets or undercuts, which interact with the swivelling levers of the gripping device, characterised in that the gripping pockets/undercuts (40) are located on one side of the good (4).

24. Good according to claim 23, characterised in that the gripping pocket/undercut (40) is located on the side of the good facing the gripping device (6).

25. Good according to claim 23, characterised in that the good (4) is designed as pallet and the work piece can be mounted on the pallet.

26. Good according to claim 23, characterised in that the planes of the undercuts/gripping pockets (40) of the good, respectively the pallet (4), the planes interacting with the swivelling lever (60) of the gripping device, are parallel or at an sharp angle to an external plane, in particular one facing the gripping device (6).

27. Good according to claim 23, characterised in that the gripping pockets (40), respectively the undercuts, are arranged, respectively accessible, on the side of the pallet (4) opposing the work piece (8).

28. Good according to claim 23, characterised in that the gripping pockets (40), respectively the undercuts, are shaped by recesses of the good.

29. Good according to claim 23, characterised in that the good, in particular the pallet (4), is designed like a case or a frame (41), and the internal edge of the case, respectively the frame (41) forms at least section-wise the undercut, respectively the gripping pocket (40).

30. Loading system for a machining station which machines on work pieces, the loading system having a gripping device, which interacts with a good, for example a work piece directly or a pallet carrying the good, characterized in that the gripping device (6) can be positioned relatively to the pallet/the good (4) in such a way that the swivelling levers (60) of the gripping device can engage in undercuts/gripping pockets (40) in the surface (48) of the pallet/the good (4) which faces the gripping device (6).

31. Loading system according to claim 30, characterised in that the swivelling levers (60) grip the good, respectively the pallet (4), from above.

32. Loading system according to claim 30, characterized in that the good is suspended from the gripping device.

33. Loading system according to claim 30, characterised in that the good (4) is, for the time being, supported by a support (7), in particular a conveying line, and the interaction of the swivelling levers (60) with the good (4), in particular on the inclined edge of the good (4), lifts the good (4) slightly, and, after that, the support and/or the gripping device is moved away.

34. Loading system according to claim 30, characterized in that the good is, for the time being, supported on a support, and the support (7), respectively the conveying line, can be moved away in a horizontal plane.

35. Loading system according to claim 30, characterized in that the good is, for the time being, supported on a support, and at least a part of the support (7), for example a roller conveyor (72) of the conveyor line can be moved away, in particular swivelled away, in a plane orientated essentially horizontally.

36. Method for loading a machining station with a work piece, the work piece being held by a gripping device directly below or indirectly by a pallet, the gripping device having swivelling levers, which hold the work piece/pallet, and the work piece/pallet being conveyed in a clamping device, in particular the machining station, by the gripping device, and the clamping device having at least one holding device which interacts with the edge of the pallet or work piece, afterwards the holding device and the pallet, respectively the work piece moving relatively toward each other, in particular lifting it, that the pallet/the work piece sits close at least to the holding device, afterwards the pallet/the work piece being clamped and eventually the swivelling levers being swivelled outside and becoming disengaged with the pallet/the work piece.

37. Method according to claim 36, characterized in that the movement of the holding device is derived from the movement of the work piece sledge of the machining station.

38. Method according to claim 36, characterised in that the gripping device deposits the work piece on the holding device or picks it up.

39. Method for unloading a machining station with a work piece, the swivelling levers of a gripping device engaging in the pallet or the work piece clamped by the clamping device of the machining station in order to hold it, afterwards the clamping device being released, and then at least one holding device of the clamping device being moved, in particular being lowered, in such a way that the gripping device carries the work piece either directly or indirectly by a pallet, and after that the gripping device conveying the pallet/the work piece out of the machining station.

40. Method according to claim 39, characterised in that the movement of the holding device is derived from the movement of the work piece sledge of the machining station.

41. Method according to claim 39, characterised in that the gripping device deposits the work piece on the holding device or picks it up.

Description:

The invention refers to a loading system for a machining station which machines on work pieces, the loading system having a gripping device, which interacts with a good, directly with the work piece or a pallet carrying the work piece.

BACKGROUND OF THE INVENTION

The invention refers also to a gripping device, which serves for gripping goods like work pieces or pallets carrying work pieces. Furthermore the invention comprises a good, for example a pallet carrying a work piece or a work piece itself, which serves in particular for the interaction with a gripping device, for example in the loading system mentioned before.

In the automatic production the work piece has to be handled in various ways. Between the single machining stations it has to be conveyed, it has to be, if necessary, turned around, rotated or changed in its position. It is often convenient to move the work piece along a conveying line and to arrange the machining stations rectangular to it and to provide special loading devices which provide the conveying of the work pieces from the conveying line to the machining station and back again.

For that purpose special robots are known which grip the pallet with very complicated claw arms or clamping devices and lift it from the conveying line in order to bring it to the machining station.

The use of such robots for this operation, however, is very expensive.

In the state of the art a work piece changing device is known from the German DE-OS 100 53 804 where L-like gripping devices grip from the outside a good which has to be conveyed. The good has corresponding grooves on its edge into which the gripping devices engage.

It is a disadvantage in this suggestion that the work piece can only move along a linear axis with the work piece changing device proposed.

BRIEF SUMMARY OF THE INVENTION

It is an object of the invention to find an arrangement which makes the picking up, respectively the depositing, of goods, in particular for loading of machining stations, more flexibly.

This problem is solved by a gripping device which serves for gripping goods like work pieces or pallets carrying work pieces, and the gripping device has a gripping drive which operates swivelling levers in such a way that they engage in a first position in gripping pockets or undercuts of the good in a holding way and that they are swivelled out of them in a second position and release the good in such a way that good and gripping device can move relatively to each other in one plane.

In the solution according to the state of the art such mobility is not possible. The angled gripping devices are simply drawn back relatively to the work piece and release it, however, they remain in a position beside the work piece, making a relative movement between the work piece (the good) and the gripping device along the linear axis possible. According to the invention, however, the impeding elements are moved back so far that good and gripping device can move in one plane relatively to each other. The flexibility of such an arrangement increases considerably. The gripping device according to the invention is used, for example, to lift goods, for example work pieces which have to be machined on (with or without pallet) from a conveyor line (for example removal or supply line) or to deposit them. The mobility of the gripping device is here linear and often angled, in particular orientated rectangular to the conveying direction of the conveying line. According to the solutions of the state of the art first of all one had to wait until the good which has to be conveyed is exactly positioned in the direction of the axis of the movement direction of the gripping device. The complete machining process had to be planned accordingly. According to the invention this time is not decisive anymore. The gripping device can appear in the take-over place before, during or after supplying the good which has to be conveyed, or it can be present there which accelerates the machining process considerably. The arrangement also becomes considerably more flexible by that. An essential advantage, however, is the fact of the increased speed for the change of goods as the gripping device is quickly available again and thus the stop periods of the machining station occurring during the change of work pieces are reduced. This results finally in a higher efficiency of the machining stations equipped with the invention, respectively of a machining line with such machining stations.

The advantage mentioned above does here not only occur when the work piece is picked up from the supplying conveyor or deposited, in the same way it can be used also in the machining station, namely when the good has been passed into a corresponding clamping device of the machining station. In the same way the advantages of the invention appear here also.

The problem of the invention is furthermore solved by a good, for example a pallet carrying a work piece or a work piece, the good having at least gripping pockets or undercuts which interact with the swivelling levers, and the gripping pockets, respectively the undercuts, are located on one side of the good.

According to the invention it is possible that either the work piece itself has corresponding designs for interaction with the gripping device or the work piece is mounted on a pallet, and the pallet itself has a corresponding design. The chosen term good therefore comprises a plurality of possibilities (e. g. pallet, work piece and so on) and the good may also consist of several parts.

The concentration of all gripping pockets and undercuts on one side of the good makes it easier that the swivelling levers can be moved away in a simple way even in such a way that the good and the gripping device can be moved in one plane relatively toward each other. A positive side effect is the fact that the arrangement is space-saving. As the working area within the machining station is comparatively expensive and should be used more for machining on large work pieces than to occupy the space with pallets which are not machined on or gripping devices, by means of the suggestion according to the invention for the good the flexibility of such an arrangement is increased considerably as a larger opportunity of machining is reached.

Beside this space-saving arrangement the proposal according to the invention also allows a design of the good, but also a high accessibility for machining tools to the good. In the suggestions according to the prior art the good is gripped at least on two sides and at least these regions, besides the contact surface in between, are not available for machining anymore. According to the solutions in the state of the art a re-clamping is necessary for a machining on several sides what is correspondingly time consuming. The invention avoids this as from the theoretically available six sides five sides are actually available for machining and only on one side the necessary elements of the gripping devices engage in correspondingly provided gripping pockets or undercuts. This also contributes eventually to an increasing of the efficiency as by means of that a more effective machining results, without stop periods of the machine because of re-clamping.

Furthermore the problem according to the invention is also solved by a loading system for a machining station, the machining station machining on work pieces and the loading system having a gripping device which interacts with a good, a work piece directly or a pallet carrying the work piece. The loading system is here characterised by the fact that the gripping device can be positioned with regard to the pallet, respectively the good, in such a way that the swivelling levers can engage in undercuts in the surface of the pallet, respectively the good, facing the gripping device.

By means of the embodiment of the loading system according to the invention the flexibility of the arrangement is increased in that way that the good can be machined on from almost every side. The complete arrangement is therefore designed very space-saving, increasing the effective working area in the machining station accordingly. Exactly the use of the also proposed gripping device according to the invention and the good according to the invention in the loading system according to the invention allows an even higher flexibility as by means of this the good can be conveyed flexibly and thus also can be brought and also removed again (after a corresponding machining) in and from the machining station.

In order to solve this problem the invention proposes also that the loading system which comprises the gripping device on the one hand and the pallet which has to be conveyed on the other hand, has to be adjusted to one another and improved, as described in the following. The invention here does not only extend to the loading system altogether, but also to the individual details which belong to the invention.

First of all the invention has a gripping device which serves for gripping the pallets carrying the work pieces. It has a gripping drive which operates swivelling levers in such a way that they engage, in a first position, in gripping pockets or undercuts of the pallet in a holding way and that they are, in a second position, swivelled out of them and release the pallet. The use of swivelling levers, which are supported rotatably around an axis, has considerable advantages as with one rotational drive, if necessary, two orthogonal linear movements are saved. It is sufficient to position the gripping device above the pallet, and the swivelling levers are lowered by the swivelling movement so far that they can interact with the pallet, then run into the undercuts, that means they swivel further in order to grip the pallet safely. Such a design is really simple as well as it is reliable.

In a preferred embodiment of the invention it is provided that the plane in which the good and the gripping device can move relatively toward each other, is rectangular to a connection line between the good ad the gripping device. It is, for example, provided here that the connection line is also at the same time parallel to an axis of movement in order to bring, for example, the good relatively to the gripping device. This may be, for example, a lifting or lowering movement. The connection line, however, can even be orientated deviating from this linear axis. It is, for example, also defined by the connection line of the respective gravity center or defined by one or two axes of symmetry of the good or the gripping device.

In another variant of the invention it is suggested that the plane is parallel to a contact surface between the good and the gripping device. As far as the contact surface is actually a plane surface, the plane in which the good and the gripping device can move toward each other is parallel to it.

Preferably here the contact surface may be rectangular to the relative movement of good and gripping device, that is, if the gripping device and the good interact in a holding way.

Conveniently the arrangement is made in such a way that the good and the gripping device can move toward each other without collision. Exactly by that it is achieved that a high mobility and a high flexibility of the invention results.

Preferably it is provided that the distance of the swivelling levers is smaller than the external dimension of the good. By means of such an embodiment it is achieved that the complete arrangement is as space-saving as possible. The swivelling levers then take hold preferably on one side of the good. Beside a space-saving arrangement also a high flexibility in the machining possibilities of the good in the working area result as no obstructing contours cover the external surface of the good. Even the change of the good from a supply line, respectively a removal line, to the gripping device is carried out accordingly space-saving as the embodiment of the gripping device does not limit the maximum width of the work piece and thus the supply and removal line.

Another advantage of the invention is the fact that the swivelling axis of the swivelling levers is parallel to the plane. By means of such a design the geometric relations and constructive solutions are simpler, however, naturally a solution belongs to the invention where the swivelling axis of the swivelling levers includes a certain angle to this plane.

Preferably it is proposed that the swivelling levers interact coming from the same side with the respective gripping pockets and undercuts of the good. This also contributes to a realisation as space-saving as possible of the arrangement according to the invention. The swivelling movement of the swivelling levers is here preferably in an opposite direction, for example from the inside to the outside or from the outside to the inside in order to interact with the correspondingly arranged gripping pockets and undercuts of the good. However, as each of the swivelling levers engage on one side of the good, the other sides remain, as already mentioned several times, free for machining.

In another variant of the invention it is provided that the distance of the swivelling axes of the swivelling levers is smaller than the external dimensions of the good. In a variant of the invention it is actually possible to arrange the swivelling levers in such a way that the distance is smaller than the external dimensions of the good, however, the corresponding swivelling axes are located outside the good. Vice versa it is possible to choose the distance of the swivelling axes smaller than the external dimensions of the good, realising of course a space-saving construction accordingly. However, even in this variant it is possible that, although the distance of the swivelling axes is smaller than the external dimensions of the good, the distance of the swivelling levers is larger than the external dimensions of the good. All these variants belong to the invention.

Furthermore it is proposed that the gripping device has a contact plate and the outer surface of the good sits close to the contact plate in the first position. In the first position of the swivelling levers it is provided that they engage in gripping pockets or undercuts of the good in a holding way. By means of this holding movement the good is moved against the gripping direction, this direction is limited by a contact plate of the gripping device accordingly to which the external surface of the good sits close. Alternatively it is provided that the contact plate also forms the contact surface between good and gripping device, the definition of the plane. The advantage of this embodiment is the fact that the swivelling levers move the good against a fixed stop, the contact plate.

Alternatively it is also possible to do without such an interaction of the contact plate and the external surface of the good, and to position the good, held only by the swivelling levers, in particular suspended, one or two degree of freedom remaining, and to hold it that way.

In a preferred embodiment of the invention it is suggested that the gripping device can be moved by a running carriage, in particular with a running carriage drive, in a guide. In connection with this invention also a loading device is mentioned, the loading device serving in particular for loading and unloading of machining stations with work pieces mounted on pallets, and the loading device having a guide on which a running carriage can be moved preferably by a running carriage drive, and the running carriage carrying a gripping device. By means of the design with a running carriage it is possible to move the gripping device between several points securely back and forth. It is provided here that the running carriage drive is, in a first variant, arranged on the running carriage itself or the running carriage drive, on the other hand, is carried out, for example, by a belt drive or a rolling spindle drive and the like which does not run together with the gripping device.

For the arrangement of the good picked up by the gripping device the invention provides several variants with regard to the position to the running carriage. As the invention is not determined to a suspended or standing arrangement of the good with regard to the gripping device, it is, according to the invention, possible that the gripping device is located with the picked-up good below or above the running carriage.

An essential advantage of the invention, however, is in particular the fact, that the gripping device, in particular with the picked-up good, projects beyond the carriage. This means that the good is not orientated directly above or below the running carriage, but the running carriage has a carrier on which the gripping device is located horizontally opposite shifted relatively to the running carriage, and therefore achieves a projection of the conveyed good. By means of such a design in particular loading of a machine tool becomes considerably easier. The guide for the running carriage does not have to be integrated in the working area, the expensive working area remains free of it.

In another variant of the invention it is proposed that the gripping device is narrower than the good, respectively the pallet. It is suggested that the gripping device is realised in a very space-saving way so that the constructive height, respectively the width, of it is as small as possible and in particular narrower than the width of the good, respectively the pallet. As the height of the gripping device limits eventually the work piece height which can be used in the working area, by means of a very slim design of the gripping device the working area is used optimally. In this connection the invention is not limited either to mounting the work piece which has to be machined on basically on a pallet, as the pallet actually needs an according constructive height for which the working area cannot be used. Therefore the gripping device according to the invention has to seize generally a good which can either be a work piece mounted on a pallet as well as the work piece directly. Naturally it is also striven for that the pallet should be constructed narrowly, as well as stable and reliably in order to use the expensive working area optimally.

Naturally the invention leads also to corresponding adjustments of the pallet. It has at least gripping pockets or undercuts which interact in a suitable way with the swivelling levers on the side of the good. The advantages resulting from that have already been pointed out in the beginning.

There are a number of different variants to it. It is, for example, possible that the gripping pockets, respectively the undercuts, are formed by recesses of the pallet. The pallet, which is, for example, shaped like a slab, has corresponding recesses on some spots.

Conveniently it is provided in another variant according to the invention that the gripping pocket/undercut is located on the side of the good facing the gripping device. This results in a very space-saving arrangement.

Alternatively it is, however, also possible that the pallet is designed like a case or a frame and the internal edge of the case, respectively the frame, forms at least section by section the undercut, respectively the gripping pocket.

Depending on the purpose such a pallet may be already sufficient to hold one or more work pieces reliably. A comparatively large and heavy pallet is not decisive here. However, the invention allows to be used nevertheless with pallets of this kind as the swivelling lever cleverly is able to use even suitable edges for an undercut or a gripping pocket.

In another convenient embodiment of the invention it is provided that the surfaces of the undercuts, respectively the gripping pockets, of the good, respectively the pallet, interacting with the swivelling lever are parallel or at an sharp angle to an external surface which is in particular facing the gripping device. In the prior art arrangements are known where the surfaces interacting with the swivelling lever are rectangular to the external surface, causing the lateral hold of the good by the swivelling lever. The result is arrangements which need comparatively much space and the reduced opportunity of machining. On the other hand, the suggestion according to the invention achieves that a it can be realised in a very space-saving manner, a sharp-angled arrangement, as far as it does not reach 90°, leading to the fact that by means of swivelling in the turning levers into the undercuts, respectively the gripping pockets, the good is lifted slightly. This makes the removal of the good from the conveying line or any other support easier.

Advantageously the gripping pockets, respectively the undercuts, are located, respectively are accessible, on the side of the pallet opposite to the work piece. Therefore the gripping mechanism does not obstruct the free access to the work piece, the machining opportunity of the work piece is not impaired. The invention allows, however, that it is basically arranged on the same side on the pallet as the work piece.

An essential advantage of the invention is achieved by the fact that the region of the undercut, respectively gripping pocket, interacting with the swivelling lever is inclined. An interaction of the swivelling lever, which moves on a circuit, with the inclined undercut, respectively gripping pocket, leads to the result that the pallet which is, for example, gripped by several swivelling levers adjusts itself in the gripping direction as inclination descending forces occur. At the same time the purpose of the arrangement is that the swivelling lever lifts the pallet on the inclined surfaces slightly already during turning in into the pallet and lifts it away from the support.

Furthermore the invention suggests that the gripping pockets, respectively the undercuts, are formed by recesses of the good. Also grooves or the like may count for that.

Furthermore the invention comprises a loading system for a machining station which machines on work pieces. The loading system comprises here a gripping device which interacts with a good, a work piece directly or a pallet carrying the work piece. Conveniently according to the loading system of the invention a gripping device and/or a good according to the invention is used. However, the invention is not restricted to that. Advantageously it is proposed to position the gripping device with regard to the pallet, respectively the good, in such a way that the swivelling levers of the gripping device can engage in undercuts or gripping pockets in the surface of the pallet, respectively the good, which faces the gripping device. By means of such an embodiment an arrangement which saves space is realised. If, for example, here the gripping device according to the invention is used it is additionally achieved that also a relative movement is possible in a plane between the good and the gripping device, which accelerates the loading and unloading of the gripping device considerably.

Conveniently it is provided that the good is suspended from the gripping device, however, the invention is not restricted to it. The good may also be conveyed with the loading system standing up. However, in the first case it is an advantage if the swivelling levers grip the good, respectively the pallet, from above and hold it that way. As the loading system is supposed to serve in particular for the supply and discharging of machining stations with suitable work pieces, the suspended conveying also allows a suspended clamping of the good/the work piece in the machining station and the suspended machining allows the use of advantages for the removal of chips.

Furthermore the invention comprises a method for loading a machining station with a work piece, the work piece being held directly or indirectly by a pallet on a gripping device, the gripping device having swivelling levers which hold the pallet, respectively the work piece (in the following described in this connection as the good) and the good being conveyed by means of the gripping device in a clamping device, in particular of the machining station, and the clamping device having at least one holding device, which interacts with the edge of the pallet or the work piece, after that the holding device and the good being moved, in particular the holding device being lifted, relatively to each other in such a way that the good sits close to at least the holding device, after that the good being clamped and eventually the swivelling levers being turned outside and coming out of engagement with the good.

The essential advantage of the invention is in particular the fact that the edge region of the good (that means the work piece, respectively the pallet) is not necessary for the gripping device as the gripping device does not interact with the good by means of swivelling levers on the edge of the good. The invention allows here basically that the good is turned around a, for example, vertical axis, and then is deposited again in the clamping device and even in this position the gripping device does not obstruct or impede the clamping process. According to the invention it is provided that the swivelling lever is turned outside finally in such a way that it is disengaged from the pallet, respectively the work piece. Also at this time already another movement is possible again between the good and the gripping device in one plane as the swivelling levers are turned back so far that they do not obstruct anymore.

In this connection the invention also refers to a method for unloading a machining station with a work piece, the swivelling levers of a gripping device engaging in the pallet or the work piece clamped by the clamping device and the machining station in order to hold it, after that the clamping device being released and then at least a holding device of the clamping device being moved relatively, in particular being lowered, in such a way that the gripping device carries the work piece either directly or indirectly through the pallet, and after that the gripping device conveying the pallet, respectively the work piece out of the machining station. Also during unloading the machining station the advantages of the invention become clear as, in the same way as during unloading, even during loading there is no risk of a collision between the clamping device, on the one hand, and the gripping device, on the other hand. However, if there is no risk of a collision between these two elements a very quick and reliable clamping is carried out without expensive translators which otherwise could be necessary, or intermediate holding devices and so on. These advantages characterise the invention during loading as well as during unloading of a machining station.

Preferably the holding device is shaped like a U (a U in horizontal position) so that one limb serves as support.

Conveniently the holding device interacting with the edge of the good (that is the edge of the work piece or the pallet) is a part of the work piece sledge and therefore the movement of the holding device is derived from the movement of the work piece sledge of the machining stations. This axis of movement is present anyway as the work piece sledge serves for positioning the work piece for machining purposes. During the phase where the work pieces are changed usually this axis is not needed, however, it is now used additionally according to the suggestion of the invention, making a corresponding additional effect possible without more expenses. Conveniently this is the vertical Y-axis of the machining station. Of course, it is alternatively provided that the movement of the holding device is carried out by a separate drive. This may be a linear or also a rotational movement.

Alternatively it is also provided according to the invention that the relative movement between the holding device and the work piece is not derived from the holding device, but the gripping device deposits the work piece on the holding device. For example, the gripping device has a suitable linear axis.

BRIEF DESCRIPTION OF THE DIFFERENT VIEW OF THE DRAWINGS

The invention has been described in the further claims and shown in the drawing. In the drawings:

FIG. 1 in a three dimensional view a machining station according to the invention with the loading system according to the invention;

FIG. 2 in a side view the loading system according to the invention;

FIGS. 3 and 5 in each top view a variant of the gripping device according to the invention;

FIG. 4 in another view according to FIG. 2;

FIG. 6 another detail of the gripping device, respectively the loading system, according to the invention;

FIGS. 7 and 8 in each view another variant of the invention and

FIGS. 9a to 9d different steps of a method according to the invention for loading a machining station.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a loading device 2 according to the invention, in particular for loading and unloading machining stations 9 with work pieces 8 mounted on pallets 4, the loading device 2 having a guide 21 on which a running carriage 24 (see FIG. 2) can move and the running carriage carrying a gripping device 6.

It is an advantage that the machining station 9 can be closed by a door 90 through which the loading device 2 conveys the pallet in, respectively out of, the machining station, and the opening, respectively the closing, movement of the door 90 is eventually forced driven derived from the drive 20 of the running carriage. For the drive of the door 90 a door drive 91 is provided. It comprises three rollers, the center roller of which is driven by a drive shaft, and between them a belt or a strap is guided meander-shaped for the drive of the door 90 or its door segments. The drive shaft transfers a turning moment of the deflection cylinder 22, which is driven itself by a traction mechanism 23 of the drive 20 of the running carriage. The arrangement shown here is in particular convenient if, for example, conical work pieces 8 are conveyed in which are wider on the bottom than they are on top. Here the door 90 is drawn up and opens the first, bottom region, that is the region where the conical work piece enters the machining station at first. It is possible without any problem here to adjust the translation of the door drive 91 in such a way that, when the work piece is conveyed in, the door has the proper opening width.

According to the invention it is suggested that the opening, respectively the closing, movement of a door 90 closing the machining station is derived from the drive of the running carriage, respectively from the movement of the running carriage 24.

In FIG. 1 two loading devices 2 are shown arranged one above the other. In the upper loading device the work piece 8 is still outside, in the bottom one the work piece 8′ is within the machining station 9.

The loading device 2 comprises, as for example shown in FIG. 2, the gripping device 6 which seizes the pallet 4, and elements for the operation of the gripping device 6, that is a drive 20 of the running carriage of the guide 21 and the running carriage 24.

FIG. 2 indicates that the gripping device 6 has a working cylinder as gripping drive 61, which, as it is explained in the following, finally acts via shafts 62 on swivelling levers 60 which engage in gripping pockets 40 on the pallet, respectively the edge of the pallet. In FIG. 2 the second position of the swivelling levers 60′ is indicated by dashed lines where the swivelling levers do not engage in the pallet, but release it.

Cleverly the arrangement is chosen here in such a way that only one gripping drive 61 acts on two shafts 62 and drives them in an opposite direction, so that both shafts move their swivelling levers in the same way, for example, to the outside in the gripping pockets.

In a preferred embodiment of the invention two swivelling levers 60 are provided per shaft 62 and two shafts 62 are arranged, one pallet 4 being held by means of four swivelling levers 60 by the gripping device 6.

Furthermore it is a result of FIG. 2 that each of the swivelling levers 60 are swivelled to the edge of the pallet, however, it is possible without any problems to chose another arrangement where, for example, the swivelling levers grip the edge from the outside.

In FIG. 2 the situation is shown where the gripping device 6 grips a pallet 4 located on a conveying belt 7 from the inside. The external edge of the pallet is here supported by the drive wheels 70, and it is convenient here to chose the arrangement as shown because this way there is no collision in the region of the edge. However, if the arrangement of the conveying belt is chosen in another way it is possible without any problems to have the swivelling levers engage on the edge of the pallet also from the outside.

Furthermore reference number 69 in FIG. 2 shows the swivelling axes of the swivelling levers 60. The first position of the swivelling lever 60′, which is moved back, is indicated by the dashed lines. In the example shown here the pallet 4, which in this connection is also characterised and numbered as good 4, is lifted by the swivelling movement of the swivelling levers 60. The swivelling levers 60 here engage in gripping pockets 40 in the surface 48 of the pallet 4 facing the gripping device 6.

In the example shown here this surface 48 is at the same time also the contact surface 47 as this contact surface 47 of the good 4 sits close to the gripping device 6.

According to the invention it is provided in particular for the gripping device that the good 4 and the gripping device 6 can move in one plane relatively to each other. In FIG. 2 the plane is vertically to the paper plane, respectively rectangular to the connection line 46, which is drawn here as symmetric axis of the good.

FIG. 3 shows in a top view the gripping device 6 engaging in a pallet 4. The pallet 4 is here, for example, designed frame-like 41, the work piece 8 is covered by the pallet 4 and not visible.

The gripping drive 61 eventually serves for the drive of the swivelling levers 60 via the shafts 62. The gripping drive 61 acts here on a knuckle joint arrangement 64 which is designed in such a way that it is self-locking. The knuckle joint is moved namely in the position gripping the pallet 4 beyond the dead center in such a way that the leg 65 transferring the holding force sits close to the stopper 66 and is blocked. This clever arrangement leads to the result that the weight of the work piece 8 which sits finally close to the leg 65 via the swivelling lever 60, the shafts 62, the slider 63, does not push it open but pushes it closed and thus results in a passive save connection. Therefore it is guaranteed, even if the gripping drive 61 breaks down, that the pallet is not released from the gripping drive 6. Instead of this self-locking knuckle joint arrangement 64, of course, other self locking gears can be used.

The slider 63 selects the shafts 62 one time above and one time below these shafts in order to reach by this translator movement of the slider a shaft rotation in opposite directions and to realise the swivelling to the outside of the swivelling levers 60, as shown in FIG. 2.

The movement of the loading device can be seen by means of the double arrow 26. In this case the conveyor line serving as support 7 obstructs at least one roller conveyor 72 of the conveyor line. Therefore it is provided that the pallet is supported, for the time being, on a support 7 and the interaction of the swivelling levers 60 with the pallet 4 lifts the pallet 4 slightly and, after that, moves it away and, after that, the gripping device is shifted. For that purpose it is provided that the roller conveyor 72 (as support 7) is swivelled away in a plane essentially horizontal.

In a preferred variant of the invention it is provided that the good 4 is supported, for the time being, on a support 7, in particular a conveying line or the like, and after the gripping device 6 has taken hold of the good 4, the support 7 and/or the gripping device is moved away.

FIG. 3 shows an embodiment of the gripping device according to the invention as a comparatively large construction, as it is, for example, advantageously for the loading station 2 in FIG. 1 in order to grip into the loading station. In other fields of application of the invention it is convenient to realise a comparatively compactly constructed gripping device 6 as it is arranged, for example, in FIG. 5. In a top view again the gripping device 6 is shown, however, this time without pallet. The arrangement is chosen in such a way hat it does not have to be much larger than the pallet 4 suspended below it.

In a preferred variant of the invention it is suggested that the pallet 4 is suspended from the gripping device 6. Alternatively it is naturally also possible that the gripping device is arranged below the pallet, that means the pallet stands on it.

In FIG. 4 a side view of the gripping device 6 according to the invention is shown. As the gripping device 6 needs energy for the operation of the gripping drive 61,an energy line 25 is provided in a roller chain. This may be electric energy, pneumatic or hydraulic energy.

As already illustrated in FIG. 2 it is possible that the support 7 interferes with the movement of the gripping device. In the example shown here the roller conveyors 72 can be swivelled around horizontal axes 73 in such a way (see double arrow 74) that they cannot serve anymore as support for the pallet 4. In this case, it is, for example, possible that the gripping device together with the pallet and work piece is lowered down. In the course it is provided that the pallet 4 cannot move away before the pallet is securely suspended from the gripping device. If necessary, the support 7 has to be removed also beforehand.

In the reversed case, that means when the gripping device releases the pallet again, it is provided that the gripping device 6 does not release the pallet 4 before at least one support 7 for the pallet is positioned preferably below the pallet. Of course, a number of supports can be positioned as indicated, for example the two roller conveyors 72 of a conveyor line 7 as support and the like.

FIG. 7., FIG. 8 show a gripping device according to the invention as part of an elevator for the vertical shifting of pallets carrying work pieces, which are approached on a first level, for example on a conveying line 7, and are removed on a second level, the elevator 5 having at least one line 53 connecting the first and the second level 51, 52, on which the sledge 50 can move, the sledge 50 carrying the gripping device 6.

This one as well as another example which will follow show this wide field of application of the gripping device 6 according to the invention. The conditions for the swivelling away of the roller conveyor 72 can be compared with the ones in FIG. 6.

Furthermore the invention also refers to a gripping device which is part of a turntable for the turning of pallets carrying work pieces, the turntable being rotatable around a rotational axis and the turntable having a gripping device 6 as described above. In such a case conveniently a comparatively compact construction is decisive, as it is , for example, carried out in FIG. 5. The invention allows here that the turntable can be turned around either a horizontal or a vertical axis.

Therefore the invention comprises also a turntable, respectively an elevator which is equipped with a suitable gripping device according to the invention.

In particular in FIG. 1, respectively 2, the loading system for a machining station according to the invention becomes clear, where in a clever way preferably the pallet 4 according to the invention, which is adjusted to it, interacts with the gripping device 6 which is also according to the invention. In this connection, however the invention is not restricted only to the loading system with the embodiments shown of pallet, respectively gripping device, but it can be interpreted further. Naturally it is also possible that the loading system has a loading device which does not have a gripping device as described above, but drives in any way, if necessary, with respective single drives swivelling levers which hold the pallet as described. The advantage of the swivelling levers is the fact that by means of them a lowering and a lateral movement can be carried out without additional drives.

As, for example, it is shown in FIG. 2 it is convenient that the loading device 2 has a gripping device which can be positioned above the pallet, and the swivelling levers 60 grip the pallet 4 from above. However, the invention can basically also be used in such a way that it is also possible to grip the pallet with the swivelling lever from below or even from the side, respectively diagonally. In that respect the loading system, the gripping device, respectively the invention altogether, is very flexible.

FIG. 6 shows that, for example, it is convenient for a vertical movement of the gripping device if the complete support 7, that means both roller conveyors 72, is moved away, respectively swivelled away. However, in FIG. 2 it is sufficient if only a part of the support 7, for example here the right roller conveyor 72 can be moved away, in particular swivelled away, in a plane orientated essentially horizontally. This saves corresponding axes of movement.

FIGS. 9a-d show the method according to the invention for loading a machining station with a work piece which is mounted on a pallet, the pallet being held by a gripping device which has swivelling levers.

In the position shown in FIG. 9a the pallet 4 (together with the work piece suspended from it, but not shown) is moved inside in a direction of movement vertically to the paper plane, for example in a clamping device 3. Eventually the clamping device, in particular the C-shaped holding device 30, works again as support 7. The C-shaped holding devices 30 embrace the edge of the pallet. After the pallet 4 has been moved inside completely, the clamping device 3 and/or the C holding device 30 are moved up (arrow 31), and the bottom limb of the C sits close to the pallet. This is shown in FIG. 9b. Now in a suitable, known manner clamping is carried out by means of the clamping bolt 32, which is moved down (arrow 33). Depending from the chosen arrangement of the clamping, for example a sleeve is provided in the pallet. After the clamping device has gripped securely the pallet the swivelling lever 60 can be moved back, which is indicated by the dashed drawing. In the end the pallet (according to FIG. 9c) is released from the gripping device 6, and it is possible to carry out a corresponding relative movement between the gripping device 6 and the pallet, for example to lower it and/or to retract the gripping device 6 again. This is shown in FIG. 9d. The pallet 4 is securely held by the clamping device.

In this way it is possible to load a machining station; in reversed sequence it is, of course, possible to unload the machining station.

The claims filed with the application now and to be filed later on are attempted formulations without prejudice for obtaining a broader protection.

If here, on closer examination, in particular of the relevant prior art, it turns out that one or the other feature may be convenient for the aim of the invention, however, not decisively important, of course, already now a formulation is striven for which does not contain anymore such a feature, in particular in the main claim.

References in the sub-claims relate to the further design of the matter of the main claim through the characteristics of the respective sub-claim. These are, however, not to be understood as a waiver of independent protection of the matter for the characteristics of the referred sub-claims.

Characteristics only disclosed in the description now, may, in the course of proceedings, be claimed as being of inventive relevance, for example to distinguish from the state of the art.

Characteristics only disclosed in the description or even single characteristics from claims which comprise a variety of characteristics may be used at any time to distinguish from the state of the art in the first claim, and this is even if such characteristics have been mentioned in connection with other characteristics, respectively achieve particular convenient results in connection with other characteristics.

Although the invention has been described by exact examples which are illustrated in the most extensive detail, it is pointed out that this serves only for illustration and that the invention is not necessarily limited to it because alternatives embodiments and methods become clear for experts in view of the disclosure. Accordingly changes can be considered which can be made without departing from the contents of the described invention.