Gripper

Abstract

The present invention relates to a cutting apparatus having a gripper for gripping a product, in particular a food product, having a gripper base, and having a gripper head fastened to the gripper base, wherein the gripper head comprises at least one suction device that can be acted on by vacuum and that can be brought into contact with a section, in particular an end section, of the product to suck it in, with the gripper head being releasably fastened to the gripper base.

Claims

1. A cutting apparatus for cutting food products comprising: a blade for cutting a food product, a gripper for gripping the food product, the gripper having a gripper base and a gripper head fastened to the gripper base, wherein the gripper head comprises at least one suction device that can be acted on by vacuum and that can be brought into contact with an end section, of the product to suck it in, with the gripper head being releasably fastened to the gripper base; a vacuum generation device for generating the vacuum is arranged in or at the gripper head, wherein the vacuum generation device comprises a jet pump, the jet pump comprising an ejector; wherein an interface that comprises at least one coupling section for fastening the gripper head to the gripper base and at least one drive coupling section for transferring an operating medium and/or drive energy to operate the at least one suction device is provided at the gripper head and at the gripper base to couple the gripper head and the gripper base, wherein the at least one drive coupling section comprises at least two pneumatic coupling sections, wherein the gripper head comprises the at least one a suction device being in communication with the vacuum generation device, the at least one suction device comprising a distributor block and a suction unit that is provided with a product contact surface, wherein the distributor block is releasably connected to the at least one suction device and/or the suction unit, and wherein the vacuum generation device has a chamber which is in communication with the at least one suction device via a vacuum line and in which a nozzle device is arranged that can be flowed through by compressed air in operation of the vacuum generation device.

2. A The cutting apparatus in accordance with claim 1, wherein the chamber has an outlet opening that is formed in a releasable closure element.

3. The cutting apparatus in accordance with claim 2, further comprising a first pressure line (LI) that is connected to the vacuum generation device and that has a pressure regulator; a second pressure line (L2) connected to the suction unit of the suction device, wherein the second pressure line (L2) and the chamber of the vacuum generation device are pneumatically connected via a bypass connection.

4. the cutting apparatus in accordance with claim 3, wherein a pressure sensor is associated with the second pressure line (L2), wherein the second pressure line (L2) comprises a stop valve, wherein at least one of the pressure regulator, the pressure sensor and the stop valve are arranged in or at the gripper base.

Description

(1) The present invention will be explained in the following purely by way of example with reference to advantageous embodiments and to the enclosed drawings. There are shown:

(2) FIG. 1 a perspective view of a mechanical gripper;

(3) FIG. 2 a perspective view of a gripper in accordance with an embodiment of the cutting apparatus in accordance with the invention;

(4) FIG. 3 a detail view of the gripper head of the gripper of FIG. 2;

(5) FIG. 4 a sectional view of the gripper head of FIGS. 2 and 3; and

(6) FIGS. 5 to 9 further embodiments of the gripper in accordance with the invention or of a gripper head.

(7) FIGS. 10 and 11 schematic cross-sections through a gripper head in accordance with the invention with different embodiments of a pressure reservoir.

(8) FIG. 12 illustrates a cutting apparatus.

(9) FIG. 1 shows a mechanical gripper GM that comprises a gripper base 11 and a gripper head 10M fastened thereto. Connections 50A, 50B are shown at the left end of the base 11 that enable a connection of the gripper G to an external pneumatic system (e.g. to the pneumatic system of a high performance slicer) and to other, pneumatically operated components (e.g. further grippers). The connections 50A serve for the compressed air supply; the connections 50B sere for the connection of parallel components (or vice versa). The supplied compressed air is thus “dragged through” by the gripper GM.

(10) The gripper base 11 has a fastening section 11B that enables a simple fastening of the gripper GM to a corresponding holder, for example to a holder of a high performance slicer. In the present embodiment, the gripper base 11 is pushed onto a corresponding holding section.

(11) The gripper base 11 has an interface 13 that is coupled to an interface 12 of the head 10M configured in a complementary manner. The interfaces 12, 13 each have a mechanical coupling section 14 and two pneumatic connections 16, which is shown by way of example using a vacuum gripper head 10 that is shown in FIGS. 2 and 3. The gripper head 10M has a likewise designed interface 12.

(12) The standardized configuration of the interfaces 12, 13 enables a fast change of the head 10M. The gripper head 10M equipped with claws 10K engaging into the product and operated pneumatically can be replaced with a different gripper head, for example with a gripper head 10 such as is shown in FIG. 2. with a few movements. The gripper GM thus becomes a gripper G having different properties (the base 10 is not changed in this process). The head 10 is namely a vacuum gripper unit that gently sucks in the product and nevertheless holds it reliably without mechanically gripping deeply into it. The same pneumatic connections are used here that are also required for the operation of the gripper head 10M. If required, the compressed air supply can be converted (automatically or manually) such that sterilized compressed air is provided for the gripper G.

(13) In other words, a modular system is provided by the releasable design of the heads 10, 10M that can be flexibly adapted to the respective conditions present. In a cutting apparatus having a plurality of grippers, a parallel use of mechanical grippers GM and vacuum grippers G is possible, i.e. any desired replacement of the grippers among one another or any desired use on adjacent tracks of a product supply of the cutting apparatus in accordance with the invention.

(14) Since the same base 11 can be used for mechanical grippers heads 10M and vacuum gripper heads 10, the effort for the conversion is kept to a minimum. It is only necessary to “advise” a control unit of the gripper GM which head 10M, 10 is just being used. This can also be done automatically, for example by a corresponding mechanical coding at the respective head 10M, 10 that actuates a switch at the base 11 in a suitable manner. An electric coding and/or other means for identifying the gripper type and/or even the specifically used gripper (individual identification) can likewise be used.

(15) FIGS. 3 and 4 show the gripper head 10 in more detail. The interface 12 is fastened to frame elements 18 (one not shown for reasons of clarity) at whose ends, that face the product to be held in operation of the gripper comprising the gripper head 10, a suction device 20 is arranged. An ejector device 22 is releasably fastened to the side of the suction device remote from the product. It comprises a fastening plate 24 at which an ejector block 26 is provided. The latter has a chamber 36 (see FIG. 4 with a sectional view of the head 10) that is in communication with a compressed air supply connection 28 (this is, for example, in communication with the right connection 16; the corresponding pressure line was not shown for reasons of clarity) and with an optional bypass connection 30 (see bypass 58 in FIGS. 6 and 8) (that is in communication with the left connection 16, for example). A nozzle device 56 is arranged in the chamber and the compressed air that is supplied through the connection 28 and that escapes from the chamber 36 through an outlet opening 32 flows through it in operation of the device 22. The outlet opening 32 is provided in a cover 34 that is screwed into an internal thread of the chamber 36. The nozzle device 56 is releasably connected or connectable to the cover 34 (e.g. by means of a screw connection or a snap-in connection) so that it can be simply removed together with the cover 34, for example for cleaning purposes.

(16) With a closed bypass connection 30 and with a compressed air supply through the connection 28, air is sucked in at the side of the suction device 20 facing the product via at least one vacuum passage 38 connected to the chamber 36. If a product contacts the suction device 20 such that a sealing of a suction section of the device 20 that is as complete as possible is achieved with respect to the outside space (for example, by corresponding sealing lips contacting the product and/or by blades penetrating into the product), a vacuum is created that fixes the product at the device 20. The mode of operation of the pneumatic system will be described in even more detail in the following.

(17) FIG. 5 schematically shows an embodiment of a gripper G in accordance with the invention. The latter in turn comprises the gripper base 11 having an interface 13 that is configured as complementary with the interface 12 of the gripper head 10 with respect to the mechanical and pneumatic coupling. The gripper G has a first pressure line L1 and a second pressure line L2 that—as already described—are each separable at the interfaces 12, 13. The pressure lines L1, L2 are in communication with an external pneumatic system, for example with a pneumatic system of a high performance slicer that comprises at least one compressed air source, not shown. The separating plane between the base 11 and the head 10 is indicated by a dashed line.

(18) The interfaces 12 13 enable a fast change of the gripper head 10, whether for servicing purposes or to install a gripper head 10 optimized for the respective product provided. Since the interface 13 comprises a standardized mechanical coupling and the typically used pneumatic connections such as are also used with mechanical grippers that are pneumatically operated, the gripper G can be converted fast and without problem if it is required or desired.

(19) The line L 1 is in communication with the chamber 36 of the ejector device 22 in which the nozzle device 56 is arranged. The cover 34 (partly) closing the chamber 36 (cf. FIG. 1) is not shown. In operation of the device 22, the line L 1 delivers 20 compressed air that is used by the device 22 to generate a vacuum. To be able to vary the generated vacuum, a pressure regulator 99 can be provided with which the compressed air supplied to the ejector device 22 can be provided in accordance with requirements. The regulator can be arranged outside the gripper G or in its base 11 or in the gripper head 10.

(20) In operation of the ejector device 22, the nozzle device 56 is flowed through by compressed air from the line L1, whereby a vacuum is generated in the chamber 36 in a known manner in accordance with the principle of a jet pump. The compressed air leaving the chamber 36 is indicated by an arrow. The cover 34 that closes the chamber 36 and that has the outlet opening 32 is not shown.

(21) The ejector device 22 is in communication with a suction unit 42 via at least the vacuum passage 38 that is formed in a distributor block 40. The distributor block 40 and the suction unit 42 together form the suction device 20.

(22) The distributor block 40 to which the device 22 is, for example, releasably fastened serves to “distribute” the vacuum generated. The passage 38 shown by way of example can branch off for this purpose and can “transfer” the vacuum to the suction unit 42 at a plurality of points. In other words, it is possible to provide a plurality of suction openings at the suction unit 42 such that a more homogeneous sucking in of the product is made possible. For this purpose, suitable recesses and/or grooves that are in communication with the suction openings and that are set back with respect to a product contact surface against which the product is pressed during sucking in can also be provided at the side of the suction unit 42 facing the product. The most varied sealing devices can be provided to achieve a sealing with respect to the outside space. They in particular surround a region in which the suction openings, recesses and/or grooves are provided (suction section). A single suction section can be provided that is sealed with respect to the outer space; a plurality of mutually separate suction sections are, however, likewise conceivable.

(23) To achieve a simple and fast adaptation of the gripper head 10 to the respective product to be gripped, the suction unit 42 in the present embodiment is releasably fastened to the distributor block 40. It can therefore be changed quickly as required. The distributor block 40 thus acts as a standardized “adapter” between the ejector device 22 and the suction unit 42. The distributor block 40 is likewise releasably connected to the further components of the head 10 to be able to be replaced quickly as required (see the separation plane indicated by the dashed line).

(24) While the line L1 serves for the generation of a vacuum, the line L2 delivers compressed air to the suction unit 42 as required via at least one pressure passage 44, preferably a plurality of pressure passages 44, in the distributor block 40 (corresponding passages in the unit 42 are not shown). It is understood that the passage/passages 44 is/are not in communication with the at least one vacuum passage 38. This compressed air is used to actively release the sucked in product from the suction unit 42 and thus, for example, to eject an end piece of the product. Corresponding ejection nozzles of the suction unit 42 that can be acted on by compressed air are preferably provided in a marginal region of the suction section of the suction unit 42 (not shown).

(25) A stop valve 46 arranged in the line L2 acted on by compressed air is opened to eject the product. Compressed air thereby moves via the line(s) 44 to the ejection nozzles of the suction unit 42, whereby the product is expelled. The compressed air supply via the line L1 is preferably interrupted in this process.

(26) The stop valve 46 can in particular be configured such that it is automatically opened by the pressure present in the line L2. If the pressure in the line L2 exceeds a predefined threshold value, the valve 46 opens to actively eject the product by means of compressed air. The above-described configuration of the stop valve 46 is simple and robust in construction and makes separate control lines unnecessary.

(27) The pressure present in the pressure line L2 can be monitored by means of a pressure sensor 48 that is connected to a control device 54. With a closed stop valve 46, the vacuum applied to the product can also be monitored.

(28) FIG. 6 shows an alternative embodiment of the pneumatic system provided for the operation of the gripper G. It is in principle based on that of FIG. 5. Here, however, the chamber 36 is in communication with the line L2 via a bypass line 58. As soon as the line L2 conducts compressed air, this compressed air is also supplied to the chamber 36. The ejection is thus also amplified via the vacuum passage 38. Alternatively to the embodiment shown, the bypass can also be provided in the distributor block 40. There is then a connection between the passages 38 and 44. This modification is also possible in the embodiment shown in FIG. 8.

(29) FIG. 7 shows a further alternative embodiment of the pneumatic system provided for the operation of the gripper G. The gripper G in accordance with FIG. 7 likewise comprises a stop valve 46 in its base 11 that is, however, in communication with the pressure line L1 (bypass line 58′). The stop valve 46 can be closed or opened via a switching device 52. A switching pulse or a control pressure required for this is provided via the pressure line L2′. The valve 46 can generally also be electrically controlled.

(30) With an open valve 46, a compressed air line L3 is connected to the pressure line L1. The pressure passage 44 is thereby acted on by compressed air, which results in an ejection of the sucked in product. The pressure present in the line L3 is in turn monitored by means of the pressure sensor 48. With a closed valve 46, the vacuum acting on the product and/or an effective closing of the ejection nozzles, which can be assessed as a sign of an effective holding of the product, can in turn be monitored (this applies to all the embodiments shown). The pressure sensor 48 is connected to the control device 54 that can also be used for the regulation as required of the pressure in the line L1 and for the generation of a control pressure in the line L2′ (this also applies to all the embodiments shown).

(31) For reasons of completeness, it is again pointed out that the passages 44 and 38 in the distributor block 40 do not communicate with one another.

(32) FIG. 8 shows a somewhat modified embodiment that is based on FIG. 7. As in the embodiment in accordance with FIG. 6, the chamber 36 is here in communication with the line L3 via the bypass line L3. As soon as the line L3 conducts compressed air, this compressed air is also supplied to the chamber 36. The vacuum generation in the device 22 is thereby practically suppressed, even though compressed air still flows through the nozzle device 56. A bypass can also be established by a connection of the lines 44 and 38,

(33) A further embodiment of the pneumatic system provided for the operation of the gripper G can be seen in FIG. 9. The part of the system provided in the gripper head 10 is shown. It in turn comprises the ejector device 22 that is connected to the line L1. In addition, the device 22 is in communication with the suction device 20 via the vacuum line 38. The line L2 is in contract with a connection line 60 that can be selectively blocked with the aid of the stop valve 46. The stop valve 46 is controllable in dependence on the pressure present in the line L1 (e.g. via a control line 62). The valve 46 is, for example, securely closed by the pressure present in the line L1 so that the line 60 is separated from the line L2. This corresponds to suction operation. The pressure sensor 48 then measures the vacuum present in the suction device 20. As soon as pressure is applied for ejection in the line L2 and there is no longer any pressure in the line L1 (or as soon as a certain pressure threshold is fallen below there), the valve 47 opens by means of a spring integrated there and the compressed air applied in the line L2 leads to an active ejection of the product from the suction device 20.

(34) It is generally not necessary that the valve 46 or a switching device associated with it is connected to the line L1. Provision can also be made that the valve 46 is controlled by a control device 54 that is, for example, also connected to the sensor 48.

(35) FIGS. 10 and 11 show cross-sections through a gripper head 10 with different embodiments of a pressure reservoir V.

(36) As has initially been described, improved operating dynamics can be achieved by the spatial proximity of the pressure reservoir V serving as a pressure source—or at least assisting an external pressure source—to the consumers (e.g. ejector device 22 and/or expulsion devices). FIG. 10 shows an embodiment in which the reservoir V is integrated into a housing 64 of the head 10. A variant is indicated by dashed lines in which the reservoir V is installed at the head 10. It is understood that the reservoir V is connected to the further components—only schematically indicated in FIGS. 10 and 11—of the pneumatic system of the head 10. An interface or a suitable connector 66 is provided for this purpose in the dashed variant.

(37) The reservoir content in the corresponding embodiment is, for example, released by means of a switch valve as soon as the line L1 is pressureless.

(38) In the embodiment in accordance with FIG. 11, the reservoir V is likewise integrated in the head 10. The reservoir V here itself forms at least a part or a section of the housing of the head 10 so that the above-named components—or at least some of them—are received by the reservoir V. This variant is particularly space-saving and also protects said components.

(39) In both cases, the reservoir V can be a suitable hollow profile that is closed by covers at its front sides.

(40) If two or more grippers G are provided in an apparatus, in particular in an apparatus for cutting a product, they can also be connected individually and in particular directly to the pneumatic system (a grouping of grippers for the purpose of a group-wise compressed air supply is also conceivable) to simplify a selective control of the grippers GM. For example, a time-displaced ejection or expulsion of the products (see below), for example displaced by a few milliseconds, can be realized. With a separate connection of the grippers G, it can additionally be ensured that the expulsion/ejection pulse is of an equal amount everywhere. A pressure drop in the compressed air supply of one of the grippers—for instance, on an expulsion pulse—then has no effect or only a small effect on the pressure level in the compressed air supply of the other grippers. The same applies analogously to the vacuum generation in the gripper head.

(41) It is generally also conceivable that a provision and/or generation of vacuum for operating the suction device takes/take place by a pneumatic system that is separate from a system that serves for the provision of an expulsion pulse or ejection pulse.

(42) It must be mentioned for reasons of completeness that the expulsion or ejection of the product does not only have to take place by a pressure pulse acting directly on the product. Provision can also be made to effect the expulsion or ejection by elements actuated by compressed air or in a different manner, e.g. small plungers.

(43) A gripper in accordance with the present invention can—as already stated—be used in an apparatus for cutting a product, in particular in a high performance slicer. Such high performance slicers frequently comprise a plurality of grippers with which a plurality of products can be held and can thus be sliced simultaneously. It is by all means possible to use grippers of different types next to one another in such a slicer gripper.

(44) The measure in accordance with the invention of giving the gripper a modular design, namely of releasably coupling the gripper head to a base connected to the cutting apparatus, makes it possible to convert conventional high performance slicers in a simple manner. If the vacuum gripper head's “own” vacuum generation device is integrated in it, use can also be made of the compressed air connections also provided as a rule for mechanical gripper heads.

(45) A reliable gripping of a product by means of vacuum generally makes a mechanical penetration into the product superfluous so that end pieces occurring on the slicing of the product are comparatively smaller. Substantial cost advantages accompany the minimization of the product waste.

(46) The modular design of the gripper in accordance with the invention also simplifies its cleaning and maintenance.

(47) A change between a vacuum gripper head and a mechanical gripper head—and vice versa—can also take place, in the simplest case, without any real interventions or with only comparatively small interventions in a higher ranking control.

(48) The suction function of the vacuum gripper head makes it possible to hold the product to be gripped more gently than typical mechanical grippers. The gripping process per se is also more gentle since the vacuum gripping head can be led with an already working suction device in a controlled manner toward the product end. It is namely recognized very quickly by the monitoring of the vacuum by means of the pressure sensor as soon as the gripping head securely contacts the product. The measured pressure namely then drops rapidly. In contrast to this, the product is compressed on a mechanical gripping to ensure a secure penetration of the claws or needles.

(49) The monitoring of the vacuum does not only serve the recognition of a successful gripping of the product, but rather also serves for process security. If namely the measured pressure increases during the holding of the product, this can be an indication of leaks that can result in a reduction of the holding force. Such leaks can, for example, occur due to a wear of the sealing devices. Provision can be made to compare the measured pressure value with a stored reference value and to output an error message and/or a warning signal when it is exceeded/fallen below. The reference value is, for example, determined on the putting into operation of the apparatus and/or after a change of the gripper head under defined conditions. It can also be product dependent and/or load dependent. A determination of the reference value can also take place during special, suitable phases during operation. A plurality of “sampling points” are, for example, recorded, evaluated, and compared. Additionally or alternatively test measurements and/or reference measurements can be carried out with a reliably closed suction section or with reliably closed suction openings (for example using a suitable closure cap/cover).

(50) To check whether the ejection of the product, for example, by a compressed air impulse, was successful, provision can be made to again briefly activate the suction function of the gripper head and to check whether a vacuum is generated in the suction section. If this is the case, this is an indication that the product has not yet been (completely) ejected. The above-described process can be repeated once or a plurality of times as required.

REFERENCE NUMERAL LIST

(51) 10, 10M gripper head 10K claw 11 gripper base 12, 13 interface 14 mechanical coupling section 16 pneumatic connection 18 frame element 20 suction device 22 ejector device 24 fastening plate 26 ejector block 28 compressed air supply connection 30 bypass connection 32 outlet opening 34 cover 36 chamber 38 vacuum passage 40 distributor block 42 suction unit 44 pressure passage 46 stop valve 48 pressure sensor 50A, 50B connection 52 switching device 54 control device 56 nozzle device 58, 58′ bypass line 60 connection line 62 control line 64 housing 66 reservoir connector L1, L2, L2′, L3 pressure line G, GM gripper V pressure reservoir