EP3658479A1

EP3658479A1 - Vacuum chamber with easier assembly for gripper

Info

Publication number: EP3658479A1
Application number: EP18743564.9A
Authority: EP
Inventors: Julien BILLON; Pierre Milhau; Michel Cecchin
Original assignee: Coval SAS
Current assignee: Coval SAS
Priority date: 2017-07-28
Filing date: 2018-07-30
Publication date: 2020-06-03
Also published as: FR3069531B1; US11331813B2; WO2019020838A1; FR3069531A1; US20200269443A1

Abstract

Vacuum chamber for a gripper, comprising at least one fixing plate and at least one pneumatic accessory fixed in an opening in the fixing plate, characterized in that the pneumatic accessory is held in the opening by an elastically deformable tubular interface comprising an external groove in which the periphery of the opening is housed so as to provide sealing between the plate and the interface, the interface delimiting a passage extending between a first end of the interface extending into the chamber and a second end extending to outside the chamber, at least part of the pneumatic accessory being inserted in the passage of the interface.

Description

EMPTY CASE λ EASY ASSEMBLY FOR PREHENSEUR

The present invention relates to pneumatic technology and more particularly devices for gripping parts by suction.

STATE OF THE ART

A vacuum gripping device generally comprises a box associated with a source of depression to create a vacuum in the box. The box generally comprises a plate (commonly called sole) provided with suction cups. Each suction cup comprises a metal body having a first end portion fixed in a perforation of the plate and a second end portion extending outside the plate and carrying a deformable suction cup. The first end of the metal body is usually provided with a flange and a thread for gripping the plate between the collar and a nut, not to mention a seal preventing leakage between the body and the plaque.

It appears that this type of assembly is impractical and complicated both the manufacture and maintenance of the box because both the assembly and disassembly of the suction cup require partial disassembly of the box.

OBJECT OF THE INVENTION

An object of the invention is to simplify the assembly of the accessories associated with the vacuum box.

BRIEF SUMMARY OF THE INVENTION

For this purpose, there is provided, according to the invention, a vacuum box for a gripper, comprising at least one fixing plate and at least one pneumatic accessory fixed in a perforation of the fixing plate. The pneumatic accessory is retained in the perforation by an elastically deformable tubular interface having an external groove in which the perimeter of the perforation is housed so as to ensure a seal between the plate and the interface, the interface delimiting a channel extending between a first end of the interface extending into the box and a second end extending outside the box, at least a portion of the pneumatic accessory being inserted into the channel of the interface.

Thus, the interface ensures both the retention of the pneumatic accessory on the plate of the box and one sealing between the plate of the box and the interface. The assembly and disassembly of the accessory are thus easy.

Other features and advantages of the invention will emerge on reading the following description of particular non-limiting embodiments of the invention.

BRIEF DESCRIPTION OF THE FIGURES Reference will be made to the accompanying drawings, among which:

- Figure 1 is a partial schematic sectional view of a box according to the invention;

FIG. 2 is a perspective view of an accessory according to the invention;

FIG. 3 is a perspective view of an attachment interface according to a first embodiment of the invention;

FIG. 4 is a view of this interface in section along plane IV of FIG. 3;

- Figure 5 is a view similar to Figure 1 of a box according to a first embodiment;

FIG. 6 is a view similar to FIG. 1 of a box according to a second variant of FIG. production ;

- Figure 7 is a view similar to Figure 1 of a box according to a second embodiment of the invention;

- Figures 8 and 9 are views similar to Figure 1 of a box according to two variants of the second embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION With reference to the figures, the box 1 vacuum gripper according to the invention defines a sealed enclosure and comprises at least one plate 2 for attaching at least one pneumatic accessory generally designated 10. The box can be formed by assembling a frame forming the sides of the box and two parallel plates, including the plate 2, forming the main faces of the box. The box may also be formed of a C-section comprising a central core and two wings with free edges of which the plate 2 is fixed to extend parallel to the central core so as to form a tubular conduit whose ends are closed by platelets. The plate 2 is provided with perforations 3 each allowing the attachment of a pneumatic accessory 10 by means of a tubular interface, generally designated 50, made of an elastically deformable material such as an elastomer.

The pneumatic accessory 10 shown in Figures 1 and 2 is a gripping accessory commonly called suction cup.

The pneumatic accessory 10 comprises a tubular body 11, generally metallic, having a first section 11.1 connecting to the tubular interface 50 and a second section 11.2 of connection to a flexible bellows 20 forming the actual suction cup. The first section 11.1 is separated from the second section 11.2 by an external collar 11.3 and comprises an external tooth 12 shaped fir (or "fishbone") whose sloping portion extends to the free end of the first section 11.1. The first section 11.1 has a free end portion which extends beyond the outer tooth 12. The second section 11.2 comprises one or more external teeth 13 in the form of a fir tree whose steep portion extends on the side of the free end of the second section 11.2. The tubular body 11 delimits an internal channel 14.

The second end portion 11.2 is force-fitted into a sleeve 21 having an end secured to the flexible bellows 20 and an end abutting against the collar 11.3. The flexible bellows 20 and the sleeve 21 are here in one piece of elastically deformable material such as an elastomer.

The first end section 11.1 is forced into the tubular interface 50 ensuring the attachment of the pneumatic accessory 10 to the plate 2.

The tubular interface 50 delimits a channel 51 extending between a first end 50.1 of the tubular interface 50 projecting in the box 1 and a second end 50.2 projecting from the plate 2 to the outside of the box.

The channel 51 comprises a section 51.1 opening on the first end 50.1 and a section 51.2 opening on the second end 50.2. The section 51.1 has a smaller diameter than the section 51.2 and is connected thereto by a radial shoulder 51 _* 3. The radial shoulder 51.3 comprises an annular bead 51.4 extending axially in the direction of the second end 50.2. The section 51.2 has a diameter substantially equal to or slightly smaller than that of the end portion of the first end section 11.1. The tubular interface 50 further comprises an inner groove 52 formed in the section 51.2 in the vicinity of the second end 50.2 to receive the external tooth 12.

The tubular interface 50 is externally provided with an external groove 53 arranged to receive the periphery of the perforation 3 so as to ensure a seal between the plate 1 and the tubular interface 50. The external groove 53 has a projecting bottom and along which extends an annular bead 54. The annular bead 54 here has a half-round cross section.

The tubular interface 50 has a frustoconical surface 55 extending between the first end 50.1 and the outer groove 53 so that the smaller section of the frustoconical surface adjoins the first end 50.1, and a cylindrical surface 56 extending between the second end 50.2 and the outer groove 53.

The second end 50.2 of the tubular interface 50 is provided with grooves 57 extending radially from an inner circumference of the tubular interface 50 to an outer circumference of the tubular interface 50.

After mounting the box 1, each interface 50 is installed in one of the perforations 3 by engaging the tubular interface 50 by its first end 50.1 in the perforation 3 until the periphery of the perforation 3 is housed in the external groove 53. It will be noted that the annular bead 54 has a diameter greater than the diameter of the perforation 3 in such a way that the annular bead 54 is strongly pressed against the periphery of the perforation 3 and ensures a seal between the tubular interface 50 and the plate 2. It will also be noted that the outer groove 53 has a width slightly greater than the thickness of the plate 2 to facilitate the implementation of the interface tubular 50 in the perforation 3.

The accessory 10 is then put in place by introducing the first end portion 11.1 of the tubular body 11 into the second section 51.2 of the tubular interface 50 until the outer flange 11.3 abuts against the second end 50.2. of the tubular interface 50. The annular tooth 12 is then received in the internal groove 52 extending in the tubular interface 50 so that by engagement of the annular tooth 12 in the inner groove 52 the annular tooth 12 comprises a shoulder facing a flank of the inner groove 52 which ensures the retention of the body 11 in the tubular interface 50. It will also be noted that the free end portion of the first end section 11.1 then extends at least partially opposite the perforation 3 and opposes a radial deformation of the tubular interface 50 which would allow the periphery of the perforation 3 to be out of the external groove 53. Preferably, the the first end section 11.1 of the body 11 is clamped in the tubular interface 50. The end section 11.2 carrying the suction cup bellows 20 extends outwardly from the casing 1 and the tubular interface 50.

It is thus understood that the tubular interface 50 ensures the attachment of the accessory 10 to the plate 2 by a simple press fit of the first end portion 11.1 of the tubular body 2 in the tubular interface 50. The outer flange 11.3 bears on the second end 50.2 of the tubular interface 50 and provides support for the sleeve 21 integral with the bellows 20 forming the suction cup.

In the embodiment of Figure 1, the accessory 10 is associated with two other pneumatic accessories 30 and 40.

The pneumatic accessory 40 is a filter which is attached to the free end portion of the first end portion 11.1.

The pneumatic accessory 30 is a leaking valve which has been introduced into the section 51.2 before the first end section 11.1 of the tubular body 2 is itself introduced therein to be housed between the pneumatic accessory 40 secured to the first end portion 11.1 and the radial shoulder 51.3 located near the first end of the tubular interface 50. The pneumatic accessory 30 is movably mounted in the section 51.2 between a position bearing against the annular bead 51.4 forming a valve seat and a position away from the annular bead 51.4 (shown in Figure 1).

It will be noted that the pneumatic accessories 30 and

40 are fully housed in the channel 51 while the pneumatic accessory 10 ή 'is housed only partially in the channel 51 of the tubular interface 50.

The elements identical or similar to those previously described will bear a reference numerical identical to the latter in the following description of embodiments of Figures 5 to 7.

The tubular interface 50 of FIGS. 5 to 7 is identical to that previously described.

In the variant of Figure 5, the first end portion 11.1 of the tubular body 2 is longer than that shown in Figure 1 to be able to press the pneumatic accessory 40 and a pneumatic accessory 35 against the annular bead 51.3.

The pneumatic accessory 40 is as before a filter but it is detached from the free end portion of the first end section 11.1.

The pneumatic accessory 35 is a block provided with a duct extending along the central axis of the tubular interface 50 and defining a leak calibrated. The pneumatic accessory 35 was introduced into the section 51.2 before the pneumatic accessory 40 and the first end section 11.1 of the tubular body 2 are introduced therein to be housed between the pneumatic accessory 40 and the radial shoulder 51.3.

The variant of FIG. 6 is in all respects analogous to that of FIG. 5 except that the outer collar 11.3 and the second end section 11.2 of the tubular body are of larger diameter to support a bellows 20 and a sleeve 21. even larger diameters.

In the second embodiment, represented in FIG. 1, in particular adapted to the caissons 1 whose plate 2 is covered with a backing layer made of a sealing foam of elastically deformable material perforated opposite the perforations 3, tubular interface 50 is used to ensure the attachment of two pneumatic accessories 30 and 40.

The pneumatic accessory 40 is as before a filter but it is housed in the inner groove 52 of the interface 50.

The pneumatic accessory 30 is a leaking valve which has been introduced into the section 51.2 before the pneumatic accessory 40 is introduced therein to be housed between the pneumatic accessory 40 and the radial shoulder 51.3.

The pneumatic accessory 30 is movably mounted in the section 51.2 between a bearing position against the annular bead 51.4 forming a valve seat and a position spaced from the annular bead 51.4 (shown in Figure 7).

The grooves 57 make it possible to maintain a leak even if the piece to be transported is pressed against the end 50.2 of the tubular interface 50. In the variants of FIGS. 8 and 9, the tubular interface 50 comprises as before:

an outer groove 53 arranged to receive the periphery of the perforation 3 so as to ensure a seal between the plate 1 and the tubular interface 50. The outer groove 53 has a projecting bottom and along which extends an annular bead 54. The annular bead 54 here has a half-round cross section;

a frustoconical outer surface 55 extending between the first end 50.1 and the outer groove 53 so that the smallest section of the frustoconical surface adjoins the first end 50.1;

a cylindrical outer surface 56 extending between the second end 50.2 and the outer groove

53;

- A channel 51 extending between a first end 50.1 of the tubular interface 50 projecting in the housing 1 and a second end 50.2 protruding from the plate 2 outside the housing.

The channel 51 comprises a section 51.1 opening on the first end 50.1 and a section 51.2 opening on the second end 50.2. The section 51.1 has a smaller diameter than the section 51.2 and is connected thereto by a radial shoulder 51.3. The radial shoulder 51.3 comprises an annular bead 51.4 extending in axial projection toward the second end 50.2. The section 51.2 has a diameter greater than that of the pneumatic accessory 60, 70 that it is intended to receive.

The tubular interface 50 further comprises at least one relief 58 projecting radially in the channel 51 in the vicinity of the end 50.2 to retain the pneumatic accessory. The tubular interface 50 comprises here several reliefs, namely five, in the form of lugs arranged substantially in the same plane transverse to the channel 51.

In Figure 8, the pneumatic accessory 60 is a ball-shaped valve mounted in the section 51.2. The ball is engaged in the end of the channel 51 opening on the end 50.2: the reliefs 58 are elastically deformed to let the ball and then resume their undistorted state to retain the ball in the section 51.2. It is understood that the effort that the operator must exert to deform the reliefs 58 is greater than that which can exert only the ball under normal conditions of use of the box.

The ball is movable between a position in abutment against the reliefs 58, a position in which the air can circulate in the channel 51 and around the ball, and a position in abutment against the bead 51.4 which forms a valve seat, positioned in which air can not flow in channel 51.

In Figure 9, the pneumatic accessory 70 is a block 71 provided with a conduit 72 extending along the central axis of the tubular interface 50 and defining a calibrated leak. As for the pneumatic accessory 60, the block is engaged in the end of the channel 51 opening on the end 50.2: the reliefs 58 are elastically deformed to pass the block 71 then resume their undistorted state to retain the block 71 in section 51.2. It is understood that the effort that the operator must exert to deform the reliefs 58 is greater than that which can exercise alone the block 71 under normal conditions of use of the box.

The block 71 is movable between a position bearing against the reliefs 58, a position in which the air can circulate in the channel 51 and around the block 71, and a position bearing against the bead 51.4 which forms a valve seat, a position in which air can flow in channel 51 only at the flow rate permitted by the weakest passage section of conduit 72.

It will be noted in FIG. 9 that the fixing plate 2 is covered with a bearing layer 80 of elastically deformable material having holes 84 in line with the perforations 3 of the fixing plate 2. The elastically deformable material is here an elastomeric foam.

The bearing layer 80 here more particularly comprises a first underlayer 81 having a height greater than or equal to the height of the tubular interface 50 projecting outside the fixing plate 2, and a second underlayer 82. The sub-layers 81 and 82 are perforated perpendicular to the perforations 3. Between the sub-layers 81 and 82 extends a filter layer 83 of the portions extending opposite the perforations to provide a filtering function. The filter layer 83 is here made of a woven material.

Such a sandwich layer 80 can also be used with a box shown in FIG. 8.

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

In particular, other accessories or pneumatic components can be used with the tubular interface 50 but it is also possible to use a suction cup without using other pneumatic accessories as described here.

Although the flanks of the outer groove 50 have been described as parallel to one another, they could diverge from each other having at the bottom of the outer groove 53 a spacing of less than the thickness of the plate 2 and opposite a spacing greater than the thickness of the plate.

The presence of a bead 54 is optional, the bottom of the outer groove 53 can be straight.

The shape of the tubular interface may be different from that described: the frustoconical outer surface is advantageous but not mandatory, the number of grooves 57 may be reduced or the grooves 57 may be completely eliminated.

The valve may have any shape allowing it to perform its function and for example a cylindrical shape.

The number and shape of the reliefs 58 can be modified.

Claims

1. Vacuum housing for a gripper, comprising at least one fixing plate and at least one pneumatic accessory fixed in a perforation of the fixing plate, characterized in that the pneumatic accessory is retained in the perforation by an elastically deformable tubular interface having an external groove in which the perimeter of the perforation is housed so as to ensure a seal between the plate and the interface, the interface delimiting a channel extending between a first end of the interface extending in the box and a second end extending outside the box, at least a portion of the pneumatic accessory being inserted into the channel of the interface.

2. Housing according to claim 1, wherein the pneumatic accessory is housed substantially entirely in the interface.

3. Housing according to claim 2, wherein the pneumatic accessory is a valve.

4. Casing according to claim 3, wherein the valve is arranged to define a leakage duct.

5. Box according to any one of claims 2 to 4, wherein the interface comprises at least one radial projecting relief in the channel to retain the pneumatic accessory.

6. Housing according to claim 5, the interface comprises several reliefs in the form of lugs arranged substantially in the same plane transverse to the channel.

7. Housing according to any one of claims 2 to 6, wherein the plate is covered with a support layer of elastically deformable foam having holes in line with the perforations of the fixing plate.

8. Housing according to claim 7, wherein the backing layer comprises a first sub-layer and a second sub-layer between which extends a filter layer having portions facing punctures.

9. Housing according to any one of the preceding claims, wherein the interface comprises a frustoconical end section on the side of the first end,

A casing according to any one of the preceding claims, wherein the groove has a projecting bottom and along which extends an annular bead.

11. Box according to any one of the preceding claims, wherein the channel comprises, on the side of the first end, a radial abutment shoulder of one insert.

The casing of claim 11, wherein the radial shoulder comprises an annular bead extending axially in the direction of the second end.

A housing as claimed in any one of the preceding claims, wherein the second end of the interface is provided with at least one groove extending from an inner circumference of the interface to an outer circumference of the interface. .

14. Housing according to claim 13, wherein the groove extends radially.

15. Housing according to any one of the preceding claims 9 to 14, wherein the body is clamped in the interface and has an end section which protrudes outside the box and which carries a suction cup.

16. Housing according to claim 15, in wherein the body comprises an outer flange to bear on the second end of the interface and provide support to the suction cup.