Vacuum production device with dual function control slide and handling device comprising such a vacuum production device

Abstract

Vacuum production device, comprising at least one first ejector (1.1) having an inlet port (5.1) and a suction port (6.1). The device includes a control member (10) comprising a body (11) having at least one pressure inlet (12) and one suction inlet (13) intended to be connected respectively to a pressurized air circuit (101) and a vacuum circuit (102), and a first spool (20, 40) movablely mounted in the body (11) between a connection position of the inlet port (5.1) of the first ejector (1.1) with respect to the pressure inlet (12) and the suction port (6.1) of the first ejector (1.1) with respect to the suction inlet (13), and a disconnection position of the inlet port (5.1) of the first ejector (1.1) with respect to the pressure inlet (12) and the suction port (6.1) of the first ejector (1.1) with respect to the suction inlet. (13). Handling device comprising such a vacuum production device.

Description

[0001] The present invention relates to the field of pneumatic circuits and more particularly to the control of vacuum circuits for gripping and handling parts by vacuum. BACKGROUND OF THE INVENTION

[0002] Devices for producing a vacuum by ejection are known. Such a device comprises an ejector which has an air inlet nozzle and an air exhaust venturi which are separated from each other by an intermediate chamber communicating with the outside via a suction port. The inlet nozzle of the ejector is connected to a pressurized air circuit via a control valve and the air suction port is often equipped with a control valve or a flap. The air introduced into the inlet nozzle via an inlet port is accelerated in the venturi by creating a depression in the intermediate chamber and in the vacuum circuit via the suction port.

[0003] Some devices include several ejectors with venturis of different profiles to be able to adapt the vacuum production according to the needs. The ejectors are then each controlled by a valve and are connected to the vacuum circuit by check valves to avoid leaks between the ejectors. This results in bulk and complexity, including in the control, which makes it difficult to integrate these vacuum production devices into the machines they are intended to equip, particularly if the intended application requires a relatively compact machine. SUBJECT OF THE INVENTION

[0004] The invention aims in particular to provide a multi-ejector vacuum production device which is relatively simple and compact. SUMMARY OF THE INVENTION

[0005] To this end, according to the invention, a vacuum production device is provided, comprising at least a first ejector having an inlet port and a suction port, a second ejector having an inlet port and a suction port, a control member which comprises a body having at least one pressure inlet and one suction inlet intended to be connected respectively to a pressurized air circuit and to a vacuum circuit, a first slide mounted movably in the body between a position of connection of the inlet port of the first ejector with respect to the pressure inlet and the suction port of the first ejector with respect to the suction inlet and a position of disconnection of the inlet port of the first ejector with respect to the pressure inlet and the suction port of the first ejector with respect to the suction inlet,and a second slide mounted movably in the body between a position for connecting the inlet port of the second ejector to the pressure inlet and the suction port of the second ejector to the suction inlet and a position for disconnecting the inlet port of the second ejector from the pressure inlet and the suction port of the second ejector from the suction inlet. The control member thus ensures, by a single slide, for each ejector, the simultaneous connection of the ejector to the pressure circuit and to the vacuum circuit and the simultaneous disconnection of the ejector from the pressure circuit and from the vacuum circuit. This results in simpler control implemented by a single, relatively compact control member.,

[0006] According to a particular embodiment, the body comprises a first pressure channel and a first vacuum channel separated from each other and provided respectively with a first seat and a second seat extending in the extension of each other along a sliding axis of the first slide between its connection position and its disconnection position. The first pressure channel extends from the inlet port of the first ejector to the pressure inlet and the first vacuum channel extends from the suction port of the first ejector to the suction inlet. The first slide passes through the first pressure channel and the first vacuum channel and comprises a first valve for cooperating with the first seat and a second valve for cooperating with the second seat.The first valve and the second valve are engaged with the first seat and the second seat when the first spool is in its disconnected position, the first valve and the second valve being disengaged from the first seat and the second seat when the first spool is in its connected position.

[0007] Advantageously then, the body comprises a second pressure channel and a second vacuum channel separated from each other and provided respectively with a first seat and a second seat extending in the extension of each other along a sliding axis of the second drawer.

[0008] According to another particular embodiment, the first drawer and the second drawer form a single drawer received in a chamber provided with at least one pressure port connected to the pressure inlet and a primary vacuum port connected to the suction inlet, a first outlet port connected to the inlet port of the first ejector, a second outlet port connected to the inlet port of the second ejector, a first secondary vacuum port connected to the suction port of the first ejector, a second secondary vacuum port connected to the suction port of the second ejector. The single drawer is movable between a first position and a second position and comprises: a first pressure passage and a first vacuum passage for respectively connecting the pressure port to the first outlet port and the primary vacuum port to the first secondary vacuum port when the first slide valve is in its first position; the first slide valve being arranged to, in its second position, disconnect the pressure port from the first outlet port and the primary vacuum port from the first secondary vacuum port; a second pressure passage and a second vacuum passage for respectively connecting the pressure port to the second outlet port and the primary vacuum port to the second secondary vacuum port when the slide valve is in its second position; the first slide valve being arranged to, in its first position, disconnect the pressure port from the second outlet port and the primary vacuum port from the second secondary vacuum port.

[0009] Advantageously in this other embodiment, the chamber comprises two primary vacuum orifices, namely a first primary vacuum orifice connected to the first secondary vacuum orifice by the first vacuum passage channel when the single drawer is in its first position and a second primary vacuum orifice connected to the second secondary vacuum orifice by the second vacuum passage channel when the single drawer is in its second position.

[0010] Preferably then, the single drawer is arranged to have an intermediate position in which it disconnects: the pressure port of the first outlet port and the primary vacuum port of the first secondary vacuum port, and the pressure port of the second outlet port and the primary vacuum port of the second secondary vacuum port.

[0011] Depending on optional features, used individually or in whole or in part in combination: the device comprises at least one elastic return element mounted between the single drawer and the body to elastically return the single drawer to its intermediate position; the device comprises at least one elastic return element mounted between the first drawer and / or the second drawer and the body to elastically return the first drawer and / or the second drawer to its connection position; the control member comprises an actuator for moving the first drawer and / or second drawer at least to its disconnection position; the pressure inlet of the control member is connected to the pressurized air circuit by a proportional valve.

[0012] The invention also relates to a handling device comprising a gripper having a conduit connected to the suction inlet of such a vacuum producing device.

[0013] Other characteristics and advantages of the invention will emerge from reading the following description of particular and non-limiting embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Reference will be made to the attached drawings, including: [ Fig. 1 ] there figure 1 is a schematic sectional view of a vacuum production device according to a first embodiment of the invention; [ Fig. 2 ] there figure 2 is a schematic sectional view of a vacuum production device according to a second embodiment of the invention; [ Fig. 3 ] there figure 3 is a more precise view, in section like the figure 2 , of the vacuum production device according to the second embodiment of the invention; [ Fig. 4 ] there figure 4 is a view analogous to the figure 3 , showing this same device in use; [ Fig. 5 ] there figure 5 is a view analogous to the figure 3 , of the vacuum production device according to a first variant of the second embodiment of the invention; [ Fig. 6 ] there figure 6 is a view analogous to the figure 3 , of the vacuum production device according to a second variant of the second embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] The invention is described here in application to the vacuuming of a handling gripper. The vacuum production device according to the invention is intended to be connected to a pressurized air circuit 101 and to a vacuum circuit 102 of the gripper will be connected.

[0016] With reference to the figures, the device here comprises a first ejector 1.1 and a second ejector 1.2. It is understood that the device could comprise a single ejector or more than two ejectors.

[0017] Each ejector 1.1, 1.2 comprises a nozzle 2.1, 2.2 and an air exhaust venturi 3.1, 3.2 which are separated from each other by an intermediate chamber 4.1, 4.2. The nozzle 2.1, 2.2 comprises an air inlet port 5.1, 5.2 and the intermediate chamber communicates with the outside via a suction port 6.1, 6.2. When air is introduced under pressure into the inlet nozzle 2.1, 2.2 via the inlet port 5.1, 5.2, it is accelerated in the venturi 3.1, 3.2 creating a vacuum in the intermediate chamber 4.1, 4.2 and in the vacuum circuit via the suction port 6.1, 6.2. The venturi 3.1 here has a different profile than the venturi 3.2, the first ejector 1.1 and the second ejector 1.2 therefore offer different vacuum production performances.

[0018] The device comprises a control member 10 ensuring the connection of the ejectors 1.1, 1.2 to the pressurized air circuit 101 and to the vacuum circuit 102.

[0019] The control member 10 comprises a body 11 having at least one pressure inlet 12 and one suction inlet 13 intended to be connected respectively to the pressurized air circuit 101 and to the vacuum circuit 102. The pressure inlet 12 of the control member 10 is here connected to the pressurized air circuit 101 by a proportional solenoid valve 70 making it possible to modulate the air flow rate according to requirements.

[0020] At least one drawer is mounted to move in the body 11 between two positions to selectively connect one or the other of the ejectors to the pressurized air circuit 101 and to the vacuum circuit 102. The principle of the invention is that a single drawer is arranged to: in a connection position, connect the inlet port 5.1 (or 5.2) to the pressure inlet 12 and the suction port 6.1 (or 6.2) to the suction inlet 13, and in a disconnection position, disconnect the inlet port 5.1 (or 5.2) from the pressure inlet 12 and the suction port 6.1 (or 6.2) from the suction inlet 13.

[0021] The first embodiment of the invention will now be described in relation to the figure 1 .

[0022] In this first embodiment, the control member 10 comprises only a single slide 20 which is mounted to slide in a chamber 14 of the body 11. The body comprises a single pressure inlet 12 and two suction inlets 13.1, 13.2. The two suction inlets 13.1, 13.2 can alternatively be connected to each other. The chamber 14 is provided with: a pressure port 15 connected to the pressure inlet 12, a first primary vacuum port 16.1 connected to the first suction inlet 13.1, a second primary vacuum port 16.2 connected to the first suction inlet 13.2, a first outlet port 17.1 connected to the inlet port 5.1 of the first ejector 1.1, a second outlet port 17.2 connected to the inlet port 5.2 of the second ejector 1.2, a first secondary vacuum port 18.1 connected to the suction port 6.1 of the first ejector 1.1, a second secondary vacuum port 18.2 connected to the suction port 6.2 of the second ejector 1.2.

[0023] Drawer 20 includes: a first pressure passage 21.1 and a first vacuum passage 22.1; a second pressure passage 21.2 and a second vacuum passage 22.2.

[0024] The drawer 20 is movable in the chamber 14 between a first extreme position and a second extreme position. In the first extreme position: the first pressure passage 21.1 and the first vacuum passage 22.1 respectively connect the pressure port 15 to the first outlet port 17.1 and the first primary vacuum port 16.1 to the first secondary vacuum port 18.1; the slide valve 20 is arranged to disconnect the pressure port 15 from the second outlet port 17.2 and the primary vacuum port 16.2 from the second secondary vacuum port 18.2.

[0025] The first extreme position is therefore both a position for connecting the first ejector 1.1 to the circuits 101, 102 and a position for disconnecting the second ejector 1.2 from the circuits 101, 102.

[0026] In the second extreme position: the second pressure passage 21.2 and the second vacuum passage 22.2 respectively connect the pressure port 15 to the second outlet port 17.2 and the second primary vacuum port 16.2 to the second secondary vacuum port 18.2; the slide valve 20 is arranged to disconnect the pressure port 15 from the first outlet port 17.1 and the first primary vacuum port 16.1 from the first secondary vacuum port 18.1.

[0027] The second extreme position is therefore both a position for connecting the second ejector 1.2 to the circuits 101, 102 and a position for disconnecting the first ejector 1.1 from the circuits 101, 102.

[0028] The drawer 20 is here arranged to have an intermediate position in which it disconnects: the pressure port 15 of the first outlet port 17.1 and the first primary vacuum port 16.1 of the first secondary vacuum port 18.1, and the pressure port 15 of the second outlet port 17.2 and the second primary vacuum port 16.2 of the second secondary vacuum port 18.2.

[0029] It is understood that, in the intermediate position of the slide 20, the pressure orifice 15 is closed and none of the ejectors 1.1, 1.2 is supplied and produces vacuum. The control member 10 comprises two elastic elements 50 mounted between the slide 20 and the body 11, antagonistically along the sliding direction of the slide, to elastically return the slide 20 to its intermediate position. The intermediate position, or neutral position, can be used to ensure regulation of the vacuum level or blowing if a valve is available connected to the vacuum circuit 102 to connect a compressed air supply source.

[0030] The movement of the slide 20 between its two extreme positions is here ensured by an actuator 60 such as a pneumatic cylinder controlled by a solenoid valve or a linear electric actuator. The actuator 60 is controlled in a manner known per se, for example by a microcontroller connected to a pressure sensor arranged in the vacuum circuit 102.

[0031] The second embodiment of the invention will now be described in relation to the figures 2 à 6 .

[0032] In this second embodiment, the device comprises two slides 40.1, 40.2 each movable between the connection position and the disconnection position to control the ejector 1.1 and the ejector 1.2 respectively. The body 11 of the control member 10 comprises a first pressure channel 31.1 and a first vacuum channel 32.1 separated from each other and provided respectively with a first seat 33.1 and a second seat 34.1 extending in the extension of each other along a sliding axis of the first slide 40.1 between its connection position and its disconnection position. The first pressure channel 31.1 extends from the inlet port 5.1 of the first ejector 1.1 to the pressure inlet 12 and the first vacuum channel 32.1 extends from the suction port 6.1 of the first ejector 1.1 to the suction inlet 13.

[0033] The first spool 40.1 passes through the first pressure channel 31.1 and the first vacuum channel 32.1 and comprises a first valve 41.1 for cooperating with the first seat 33.1 and a second valve 42.1 for cooperating with the second seat 34.1. Thus: the first valve 41.1 and the second valve 42.1 are in engagement with the first seat 33.1 and the second seat 34.1 when the first spool 40.1 is in its disconnected position; the first valve 41.1 and the second valve 42.1 are detached from the first seat 33.1 and the second seat 34.1 when the first spool 40.1 is in its connected position. It can be seen on the figure 2 that the body 1 comprises a bore 35.1 extending along the sliding direction of the first slide 40.1 and putting the first pressure channel 31.1 and the first vacuum channel 32.1 into communication: this bore is provided with sealing means with the first slide 40.1 so that the first slide 40.1 slides therein in a sealed manner to prevent pressure leakage from the first pressure channel 31.1 to the first vacuum channel 32.1.

[0034] The body 11 of the control member 10 comprises a second pressure channel 31.2 and a second vacuum channel 32.2 separated from each other and provided respectively with a first seat 33.2 and a second seat 34.2 extending in the extension of each other along a sliding axis of the second slide 40.2 between its connection position and its disconnection position. The second pressure channel 31.2 extends from the inlet port 5.2 of the second ejector 1.2 to the pressure inlet 12 and the second vacuum channel 32.2 extends from the suction port 6.1 of the second ejector 1.2 to the suction inlet 13. The second spool 40.2 passes through the second pressure channel 31.2 and the second vacuum channel 32.2 and comprises a first valve 41.2 for cooperating with the first seat 33.2 and a second valve 42.2 for cooperating with the second seat 34.2. Thus: the first valve 41.2 and the second valve 42.2 are in engagement with the first seat 33.2 and the second seat 34.2 when the second spool 40.2 is in its disconnected position; the first valve 41.2 and the second valve 42.2 are detached from the first seat 33.2 and the second seat 34.2 when the second spool 40.2 is in its connected position. It can be seen on the . figure 2 that the body 1 comprises a bore 35.2 extending along the sliding direction of the second slide 40.2 and putting the second pressure channel 31.2 and the first vacuum channel 32.2 into communication: this bore 35.2 is provided with sealing means with the second slide 40.2 so that the second slide 40.2 slides therein in a sealed manner to prevent pressure leakage from the second pressure channel 31.2 to the second vacuum channel 32.2.

[0035] The slides 40.1, 40.2 have, on the side opposite the first valve 41.1, 41.2, an end portion forming a piston, received in a sealed sliding manner in a housing 43.1, 43.2 of the body 11 to define therein two chambers having volumes which vary antagonistically, namely a cylindrical rear chamber and an annular front chamber extending around said end portion forming a piston. A port for connection to a pilot valve opens into the rear chamber.

[0036] According to the second embodiment, as shown in figures 2 à 4 , the control member 10 comprises a first elastic return element 50.1 mounted between the first drawer 40.1 and the body 11 to elastically return the first drawer 40.1 to its connection position and a second elastic return element 50.2 mounted between the second drawer 40.2 and the body 11 to elastically return the second drawer 40.2 to its connection position.

[0037] The control member 10 comprises an actuator for moving each slide 40.1, 40.2 towards its disconnected position against the force exerted by the elastic return element 50.1, 50.2. The actuator is here a pneumatic cylinder 60.1, 60.2 having a piston with which the slide 40.1, 40.2 is integral.

[0038] It is understood that with the second embodiment it is possible to use the two ejectors 1.1, 1.2 simultaneously whereas this is not possible with the first embodiment.

[0039] It is also understood that, due to the position of the elastic return elements 50.1, 50.2 (which are here simple helical springs), the control device is normally open: in the event of the air supply being cut off, the slide valves 40.1, 40.2 are elastically returned to the disconnection position, venting the ejectors 1.1, 1.2 to the atmosphere and interrupting the production of vacuum.

[0040] According to the first variant of the second embodiment, shown in the figure 5 , the control member 10 comprises a first elastic return element 50.1' mounted between the first drawer 40.1 and the body 11 to elastically return the first drawer 40.1 to its disconnected position and a second elastic return element 50.2' mounted between the second drawer 40.2 and the body 11 to elastically return the second drawer 40.2 to its disconnected position.

[0041] It is understood that, due to the position of the elastic return elements 50.1', 50.2' (which are also simple helical springs here), the control device is normally closed: in the event of a cut-off of the air supply, the slide valves 40.1, 40.2 are elastically returned to the connection position so that the control member 10 maintains the vacuum in the network.

[0042] According to the second variant of the second embodiment, shown in the figure 6 , the control member 10 is devoid of an elastic element for returning the drawers 40.1, 40.2 to one or other of their positions.

[0043] It is understood that, due to the absence of an elastic return element, the drawers 40.1, 40.2 remain in their position in the event of a cutoff of the air supply. The absence of an elastic return element has the advantage of allowing equivalent travel times for the drawers, between their two positions, regardless of the direction of travel (the elastic return elements 50.1, 50.2, 50.1', 50.2' oppose the movement of the drawer in one direction and accompany the movement of the drawer in the opposite direction).

[0044] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0045] In particular, the control member 10 may have a structure different from that described and shown herein. The body may include more than one pressure port connected to the pressure inlet 12 and more or less than two primary vacuum ports.

[0046] The body may comprise more than one pressure inlet 12 and more or less than two suction inlets 13.1, 13.2. The injectors may comprise one or more venturi stages.

[0047] The suction inlet of the vacuum production device can be connected to a gripper (the part of the handling device in contact with the object to be handled), a box, a suction cup... or any other device operating with vacuum.

[0048] The device may or may not include elastic return members for the pistons.

Claims

1. Vacuum production device, comprising at least a first ejector (1.1) having an inlet port (5.1) and a suction port (6.1), a second ejector (1.2) having an inlet port (5.2) and a suction port (6.2), a control member (10) which comprises a body (11) having at least one pressure inlet (12) and one suction inlet (13) intended to be connected respectively to a pressurized air circuit (101) and to a vacuum circuit (102), a first slide (20, 40) mounted movably in the body (11) between a connection position of the inlet port (5.1) of the first ejector (1.1) with respect to the pressure inlet (12) and the suction port (6.1) of the first ejector (1.1) with respect to the suction inlet (13) and a disconnection position of the inlet port (5.1) of the first ejector (1.1) with respect to the pressure inlet (12) and the suction port (6.1) of the first ejector (1.1) opposite the suction inlet (13), and a second slide (20, 40) movably mounted in the body (11) between a position of connection of the inlet port (5.2) of the second ejector (1.2) opposite the pressure inlet (12) and of the suction port (6.2) of the second ejector (1.2) opposite the suction inlet (13) and a position of disconnection of the inlet port (5.2) of the second ejector (1.2) opposite the pressure inlet (12) and of the suction port (6.2) of the second ejector (1.2) opposite the suction inlet (13).

2. Device according to claim 1, wherein the body (11) comprises a first pressure channel (31.1) and a first vacuum channel (32.1) separated from each other and provided respectively with a first seat (33.1) and a second seat (34.1) extending in the extension of each other along a sliding axis of the first slide (40.1) between its connection position and its disconnection position, the first pressure channel (31.1) extending from the inlet port of the first ejector (1.1) to the pressure inlet (12) and the first vacuum channel (32.1) extending from the suction port of the first ejector (1.1) to the suction inlet (13), the first slide (40.1) passing through the first pressure channel (31.1) and the first vacuum channel (32.1) and comprising a first valve (41.1) for cooperating with the first seat (33.1) and a second valve (42.1) for cooperating with the second seat (34.1); the first valve (41.1) and the second valve (42.1) being engaged with the first seat (33.1) and the second seat (34.1) when the first spool (40.1) is in its disconnected position, the first valve (41.1) and the second valve (42.1) being detached from the first seat (33.1) and the second seat (34.1) when the first spool (40.1) is in its connected position.

3. Device according to claim 2, wherein the body (11) comprises a second pressure channel (31.2) and a second vacuum channel (32.2) separated from each other and provided respectively with a first seat (33.2) and a second seat (34.2) extending in the extension of each other along a sliding axis of the second drawer (40.2).

4. Device according to claim 1, the first drawer and the second drawer form a single drawer (20) received in a chamber (14) provided with at least one pressure port (15) connected to the pressure inlet (12) and a primary vacuum port (16.1, 16.2) connected to the suction inlet (13.1, 13.2), a first outlet port (17.1) connected to the inlet port (5.1) of the first ejector (1.1), a second outlet port (17.2) connected to the inlet port (5.2) of the second ejector (1.2); of a first secondary vacuum port (18.1) connected to the suction port (6.1) of the first ejector (1.1), of a second secondary vacuum port (18.2) connected to the suction port (6.2) of the second ejector (1.2); the single slide (20) being movable between a first position and a second position and comprising: - a first pressure passage (21.1) and a first vacuum passage (22.1) for respectively connecting the pressure port (15) to the first outlet port (17.1) and the primary vacuum port (16.1) to the first secondary vacuum port (18.1) when the first spool (20) is in its first position; the first spool (20) being arranged to, in its second position, disconnect the pressure port (15) from the first outlet port (17.1) and the primary vacuum port (16.1) from the first secondary vacuum port (18.1); - a second pressure passage (21.2) and a second vacuum passage (22.2) for respectively connecting the pressure port (15) to the second outlet port (17.2) and the primary vacuum port (16.2) to the second secondary vacuum port (18.2) when the spool (20) is in its second position; the first drawer (20) being arranged to, in its first position, disconnect the pressure port (15) from the second outlet port (17.2) and the primary vacuum port (16.2) from the second secondary vacuum port (18.2).

5. Device according to claim 4, wherein the chamber (14) comprises two primary vacuum ports, namely a first primary vacuum port (16.1) connected to the first secondary vacuum port (18.1) by the first vacuum passage channel (22.1) when the single drawer (20) is in its first position and a second primary vacuum port (16.2) connected to the second secondary vacuum port (18.2) by the second vacuum passage channel (22.2) when the single drawer (20) is in its second position.

6. Device according to claim 5, wherein the single slide (20) is arranged to have an intermediate position in which it disconnects: - the pressure port (15) from the first outlet port (17.1) and the primary vacuum port (16.1) from the first secondary vacuum port (18.1), and - the pressure port (15) from the second outlet port (17.2) and the primary vacuum port (16.2) from the second secondary vacuum port (18.2).

7. Device according to claim 6, comprising at least one elastic return element (50) mounted between the single drawer (20) and the body (11) to elastically return the single drawer (20) to its intermediate position.

8. Device according to any one of claims 1, 2, 6 and 7, comprising at least one elastic return element (50.1) mounted between the first drawer and / or second drawer (20, 40.1, 40.2) and the body (11) to elastically return the first drawer and / or second drawer (20, 40.1, 40.2) to its connection position.

9. Device according to any one of the preceding claims, in which the control member (10) comprises an actuator (60) for moving the first drawer and / or second drawer (20, 40.1, 40.2) at least towards its disconnected position.

10. Device according to any one of the preceding claims, in which the pressure inlet (12) of the control member (10) is connected to the pressurized air circuit (101) by a proportional valve (70).

11. Handling device comprising a gripper having a conduit (102) connected to the suction inlet (13) of a vacuum production device according to any one of the preceding claims.

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