System for gripping an object, in particular an elastomeric element, method for handling said object and installation for manufacturing tire blanks

Abstract

A system (10) for gripping an object (4) comprising a gripping member (20) configured to grip an upper surface (4a) of the object (4) along a gripping axis and a locking member (30) configured to lock the object (4) in the position gripped by the gripping member (20). The locking member (30) comprises at least one locking finger (31) in one piece and rotatable about a single tilting axis (32) secured to the gripping member (20) between an unlocked gripped position and a locked position of the object (4) gripped by the gripping member (20) in which the locking finger (31) is configured to apply a force along the gripping axis to a lower surface (4c) of the gripped object (4). Figure for abstract: Fig 7

Description

Title of the invention: System for gripping an object, in particular an elastomeric element, method for handling said object and installation for manufacturing tire blanks

[0001] The present invention relates to the field of gripping an object, in particular one of low thickness.

[0002] More particularly, the present invention relates to the gripping of strips or sheets, in particular in the manufacture of tire blanks.

[0003] The invention also relates to a method for gripping strips or plies of tire blanks during the manufacture of the blank.

[0004] A tire of a wheel of a motor vehicle generally comprises three distinct zones comprising a crown which has a crown reinforcement and a tread intended to come into contact with the ground, beads intended to ensure the fixing of the tire on a rim of a wheel and sidewalls intended to connect the crown to the bead.

[0005] The tire further comprises a metal or textile fiber structure forming a reinforcing carcass for the tire structure and making it possible to connect the crown to the beads.

[0006] To manufacture a tire blank, elements in the form of bead wires, strips or plies are successively assembled so as to form a cylindrical carcass reinforcement. The cylindrical carcass reinforcement is then transformed into a toroidal carcass reinforcement, during a step known as "shaping". During this step, the crown of the cylindrical carcass reinforcement is stretched so as to increase the diameter and the beads are axially brought together. Finally, elements in the form of strips or plies are successively assembled on the crown of the carcass reinforcement so as to additionally form a crown reinforcement and a tread.

[0007] The assembly and shaping steps are generally carried out on a cylindrical tire blank manufacturing drum, which can rotate about an axis of symmetry of revolution. The elements in the form of wires, strips or plies are placed circumferentially on the drum or on the tire blank being manufactured. The laying steps are carried out manually or automatically.

[0008] The sequence of the laying step generally further comprises a step of clamping the elastomeric element around the drum, a step of cutting the elastomeric element to the desired length and a step of welding the cut part of the elastomeric element with the end part anchored on the external surface of the drum.

[0009] During the welding step, it is necessary to bring the cut ends of the elastomeric element together. It is then necessary to grasp one cut end of the elastomeric element.

[0010] Reference may be made to [Fig.l] which represents a gripping system 1 comprising a magnet 2 configured to exert an attractive force on an object 3 of low thickness, of the order of 1mm to 5mm and elastically deformable, such as an elastomeric element.

[0011] However, due to its flexibility, the object 3 may deform when it is gripped from above and break the connection with the gripping system 1, as seen in [Fig.l].

[0012] We then observe a detachment of the object 3.

[0013] Gripping systems with retractable clamps are also known. We can refer in this regard to document CN 113400331 - A. However, such a solution does not allow a surface object to be grasped by an edge.

[0014] Document WO 2020142464 - A1 is also known, which describes a robotic end effector comprising a surface of magnets and a plurality of movable fingers defining with the surface of magnets a space for gripping a large rigid three-dimensional object.

[0015] Such a solution is not suitable for gripping a thin and elastically deformable object. Furthermore, the structure of the movable fingers is particularly complex and creates a significant bulkiness which is not compatible with the use of robots in the manufacture of tire blanks.

[0016] We also know gripping systems using a suction cup to manipulate an object.

[0017] However, the flexibility and / or texture of the object may cause sagging and open the holding surface, which results in a loss of holding effectiveness, or even total loss of the holding function.

[0018] Current gripping systems do not allow for reliable handling of an edge of a thin flexible object.

[0019] Thus, there is a need to remedy the aforementioned drawbacks.

[0020] The invention aims to improve gripping systems for flexible and thin objects, such as an elastomeric element used in the manufacture of tire blanks.

[0021] The present invention relates to a system for gripping an object comprising a gripping member configured to grip an upper surface of the object according to a gripping axis and a locking member configured to lock the object in the position gripped by the gripping member.

[0022] The locking member comprises at least one single-piece locking finger that can rotate about a single tilting axis secured to the gripping member between an unlocked grasped position and a locked position of the object grasped by the gripping member in which the locking finger is configured to apply a force along the gripping axis to a lower surface of the grasped object.

[0023] The gripping system according to the invention is dedicated to the handling of flexible and thin parts and makes it possible to couple two actions, gripping from above with a gripping member and holding by means of a movable locking finger.

[0024] The finger allows gripping once detachment has been achieved. In addition, the finger prevents the object from slipping once in contact with the gripping member. This allows, if necessary, to ensure tangential traction on the gripped object.

[0025] By “monobloc” we mean a monolithic locking finger, i.e. in a single part.

[0026] It could also be provided that the one-piece locking finger is covered with a coating or a wear part ensuring better adhesion in order to improve the pressure depending on the nature of the object to be grasped.

[0027] The locking finger is also directly connected to the tilting axis, without intermediate part(s) or other pivot connections.

[0028] Advantageously, the gripping member comprises a gripping element configured to exert an attractive force on the object along the gripping axis.

[0029] The gripping system according to the invention allows the manipulation of flexible parts reinforced with metal cables which are too flexible to be manipulated by a single magnet or too textured to be manipulated by a single suction cup.

[0030] According to one embodiment, the locking member comprises a toothed wheel or a pinion secured to the locking finger and movable in rotation around the tilting axis and a rod or rack extending along the gripping axis and provided with notches configured to cooperate with the pinion when the locking finger moves from the locked position to the unlocked position.

[0031] The locking finger is, here, integral with the pinion, so that during the translation of the rack along the gripping axis, downwards, the pinion meshes with the notches of said rack, which generates a rotational movement of the locking finger around the axis.

[0032] For example, the locking member comprises a second actuator connected to the rod and configured to move said rod in translation along the gripping axis.

[0033] The rod is, advantageously, integral with a connecting member integral with the second actuator.

[0034] The connecting member extends, for example, perpendicular to the rod.

[0035] The second actuator is preferably a pneumatic cylinder comprising a cylinder rod connected to the connecting member.

[0036] For example, the locking finger comprises a first portion whose free end is secured to the pinion, and a second portion connected to the first portion by an elbow.

[0037] The first and second portions advantageously extend along two axes forming an angle between 100° and 80° between them, preferably equal to 90°.

[0038] The second portion may comprise a free end comprising a boss extending in a direction perpendicular to the second portion and forming a contact surface with the object in the locked position of said object.

[0039] Advantageously, the tilting axis of the locking finger is perpendicular to the gripping axis.

[0040] The tilting axis is integral with a casing of the gripping member.

[0041] According to one embodiment, the gripping system comprises a plurality of locking fingers arranged in series on the same line only on one side, in particular the edge of the object.

[0042] For example, the gripping element is an element made of magnetic material, such as a magnet and / or a suction cup.

[0043] In the case of a single magnet, the object must comprise ferromagnetic particles, in order to be attracted by the magnet. The magnet is configured to grip the object from above, that is to say its upper surface and in particular a lateral edge of said object.

[0044] In the grasped position, the magnetization surface of the magnet is parallel to the object and in particular to its upper surface.

[0045] When the gripping element is an element made of magnetic material, its contact surface with the object has a surface roughness of between 6.3 and 80 Ra, in order to increase the coefficient of friction on said surface of the element made of magnetic material. A roughness such as sandpaper could also be provided.

[0046] When the gripping element comprises at least one suction cup, said suction cup comprises a generally cylindrical body and a flexible skirt extending from the body obliquely outwards and configured to come into contact with the upper surface of the object in the gripped position.

[0047] For example, the gripping member comprises a casing secured to a connection interface with the robotic arm, for example of a blank manufacturing installation. pneumatic.

[0048] For example, the casing comprises an internal housing for receiving a first actuator, for example a pneumatic cylinder configured to move the gripping element in translation along the gripping axis inside the housing.

[0049] Advantageously, the suction cup is connected to the casing of the gripping member by a hollow vertical rod intended to receive a flow of air for actuating or detaching the suction cup, said vertical rod being secured to the gripping element by screw elements forming a lower stud located inside said suction cup, the lower stud being configured to be in contact with the upper surface of the object in the gripped position and to receive the force exerted by the locking finger in the locked position.

[0050] Preferably, the gripping system further comprises an electronic control unit comprising a module for gripping an edge of the end portion of the object, a module for controlling the gripping member, in particular the first actuator, and a module for controlling the locking member, in particular the second actuator.

[0051] The gripping module comprises a module for acquiring the image of the elastomeric element by the first camera and a module for processing the 3D or 2D image with information on the depth and for determining a gripping point of the object using an image processing processor. The image processing processor is configured to determine a pickup point of the object tangentially to the edge of the object at a distance of between 1mm and 10mm, preferably between 1mm and 5mm from the start of the edge of the object.

[0052] Indeed, for reasons of access length of the locking finger, if the gripping point of the object to be grasped is too far from the edge of the object to be grasped, the gripping member does not allow effective gripping.

[0053] We thus seek to have a gripping member as close as possible to the edge of the object to be grasped to improve the positioning precision of the grasped object.

[0054] For this purpose, the image processing processor is configured to detect an edge of the object by the first 3D camera, for example, an RGB-D sensor, and to recover three-dimensional points belonging to the edge of the object.

[0055] The image processing processor is further configured to approximate the edge of the object, search for a point of tangency of said edge, evaluate the reference mark of the point of tangency and determine the center of the gripping member as a function of the point of tangency.

[0056] The grip point is then transmitted to the robotic arm

[0057] According to a second aspect, the invention relates to an assembly comprising a system as described previously and an object to be grasped.

[0058] For example, the object is an elastomeric element.

[0059] By "elastomeric element" is meant an elastomeric product possibly reinforced, calendered or extruded according to a given profile so as to form a continuous strip or sheet and, by extension, a set of pre-assembled elastomeric elements.

[0060] The object is of low thickness, of the order of 1 mm to 5 mm and elastically deformable.

[0061] By "elastically deformable" is meant a "flexible" or "soft" object which, by virtue of its shape or material, is capable of elastically deforming when subjected to external stress, for example the effect of gravity, and of returning to its initial position when the external stress ceases.

[0062] A flexible object is the opposite of a rigid object configured to resist torsional and shear forces and which does not bend under the effect of gravity.

[0063] According to one embodiment, the assembly comprises a system for holding the object in position during a welding step, configured to apply pressure to the gripped object before release by the gripping member.

[0064] The welding step is carried out by a succession of gripping and releasing the gripped object along the tangential edge of the gripped object and by rotating the drum.

[0065] Indeed, due to the flexibility of the grasped object, it tends to return to its initial position after stopping a stress exerted, so that when the gripping member pulls on the object to be grasped to place it as close as possible to the cup, it tends to return to its initial position once the gripping member 10 releases it.

[0066] The position holding system is thus configured to apply pressure to the grasped object before release by the gripping member.

[0067] The position holding system makes it possible to combat elastic return of the plated object.

[0068] According to another aspect, the invention relates to an installation for manufacturing tire blanks from at least one elastomeric element and comprising at least one robotic arm, an electronic control unit configured to control the robotic arm, a laying station comprising a drum for manufacturing tire blanks, for example mobile in rotation around an axis of rotation, and at least one first three-dimensional camera restoring a cloud of points of coordinates measured in a reference frame associated with said first camera and having a viewing axis oriented towards the elastomeric element to be grasped and configured to acquire an image of the elastomeric element to be grasped, the installation comprising at least one gripping system as described previously secured to the robotic arm.

[0069] According to another aspect, the invention relates to a method for handling an object by a system for gripping an object comprising a gripping member configured to grip an upper surface of the object along a gripping axis and a locking member configured to lock the object in the position gripped by the gripping member, the locking member comprising at least one single-piece locking finger that can rotate about a single tilting axis secured to the gripping member between an unlocked gripped position and a locked position of the object gripped by the gripping member in which the locking finger is configured to apply a force along the gripping axis to a lower surface of the gripped object.

[0070] The handling method comprises the following successive steps: - positioning of the gripping system above the edge of the object to be grasped, - translational movement along the gripping axis of the gripping member of the outer surface of the object until it comes into vertical contact with said outer surface, - tilting the locking finger around the tilting axis into the locked position in which said locking finger is in point contact with the lower surface of the object along the gripping axis.

[0071] In the locked position, the point contact of the locking finger with the lower surface of the object is located in the gripping axis, for example the magnetization axis of the gripping member when the gripping element is a magnet, i.e. normal to the object.

[0072] In the locked position, the object is sandwiched between the gripping member and the locking finger. The combination of the locking finger and the gripping element makes it possible to transmit a tangential force of between 6daN and 10daN, for example equal to 8daN.

[0073] Advantageously, before tilting the locking finger (31) into the locked position, a first actuator is actuated to actuate the attractive force of the gripping element.

[0074] In the case where the gripping element is a magnet, the magnet is in the high position, at a distance or air gap from the upper surface of the object rendering the attractive force of the magnet inoperative. The first actuator of the gripping member is then controlled in order to reduce the air gap of the magnet, that is to say to bring it closer to the outer surface of the object in the gripped position of the object.

[0075] When the gripping element is a magnet, it is advantageous to vertically move the object gripped by the gripping member by a predetermined height, between 20 mm and 30 mm, for example equal to 25 mm.

[0076] The vertical movement of the object in the grasped position by a predetermined height makes it possible to free up sufficient space for the locking finger to tilt into the locked position. Alternatively, provision could be made not to move the grasped object before the locking finger tilts.

[0077] For example, before positioning the gripping system above the edge of the object to be grasped, the point at which the object is grasped is determined by a module for acquiring the image of the object by a first 3D camera and by a 3D image processing module.

[0078] For example, the release of the object is carried out in the following three steps: the gripping system is moved into a depositing position, preferably increased by the predetermined height, the locking finger is tilted into the unlocked position, and the gripping element is deactivated, for example, moved in translation so as to increase the air gap with the surface of the object, in the case where the gripping element is a magnet.

[0079] Other aims, characteristics and advantages of the invention will appear on reading the following description, given solely by way of non-limiting example, and made with reference to the appended drawings in which:

[0080] [Fig.l] very schematically represents a gripping system according to the state of the art;

[0081] [Fig.2] is a perspective view of a gripping system according to an embodiment of the invention arranged above an object;

[0082] [Fig.3], [Fig.4], [Fig.5], [Fig.6] and [Fig.7] illustrate the successive stages of gripping the object by the gripping system of [Fig.2];

[0083] [Fig.8] and [Fig.9] represents illustrates the successive steps of gripping the object by a gripping system according to another embodiment, respectively in an unlocked position and in a locked position;

[0084] [Fig. 10] is a perspective view of a suction cup used as a gripping member of the gripping system according to [Fig.8];

[0085] [Fig. 11] is a sectional view of the suction cup of [Fig. 10];

[0086] [Fig. 12] is a perspective view of the gripping system of [Fig.2] and of a position holding system according to one embodiment of the invention and

[0087] [Fig. 13] is a flowchart illustrating the certain steps of the method of handling the object by the gripping system according to the invention.

[0088] In the remainder of the description, we consider a first reference frame or orthonormal base X, Y, Z, associated with the gripping system 10 in which we find:

[0089] - a longitudinal axis X, horizontal and extending from back to front on [Fig.3];

[0090] - a transverse axis Y, horizontal, perpendicular to the longitudinal axis X and extending from left to right in [Fig.3]; and

[0091] - a vertical axis Z, orthogonal to the longitudinal axes X and transverse Y and extending from bottom to top on [Fig.3].

[0092] [Fig. 1] illustrates a gripping system 10 for an object 4 configured to be mounted on a robotic robot (not shown) of a facility (not shown) for manufacturing tire blanks.

[0093] Object 4 is, for example, an elastomeric element.

[0094] By “elastomeric element” is meant an elastomeric product possibly reinforced, calendered or extruded according to a given profile so as to form a continuous strip or sheet and, by extension, a set of pre-assembled elastomeric elements.

[0095] The elastomeric element is of low thickness, of the order of 1 mm to 5 mm and elastically deformable.

[0096] By "elastically deformable" is meant a "flexible" or "soft" object which, by virtue of its shape or material, is capable of elastically deforming when subjected to external stress, for example the effect of gravity, and of returning to its initial position when the external stress ceases.

[0097] A flexible object is the opposite of a rigid object configured to resist torsional and shear forces and which does not bend under the effect of gravity.

[0098] The installation for manufacturing tire blanks comprises, in a manner known per se, a laying station comprising a drum for manufacturing tire blanks, an electronic control unit 40, with the acronym UCE, configured to control the laying station and the robotic robot and a product presentation platform. The UCE 40 is capable, in particular, of controlling the automatic laying of the elastomeric elements on the drum. The UCE is also capable of controlling the gripping system 10.

[0099] By “laying station” we also mean the area in which the elastomers are laid.

[0100] The installation for manufacturing tire blanks will not be described further.

[0101] As illustrated, the gripping system 10 comprises a gripping member 20 configured to grip the elastomeric element 4 from above along a gripping axis, here vertical, and a locking member 30 configured to lock the elastomeric element 4 in the position gripped by the gripping member 20.

[0102] As illustrated, the gripping member 20 of the gripping system 10 comprises a casing 21 secured to a connecting interface 11 with a robotic arm, for example of a pneumatic blank manufacturing installation.

[0103] The casing 21 comprises an internal housing 22 for receiving a first actuator, for example a pneumatic cylinder.

[0104] The gripping member 20 further comprises a gripping element 23, here an element made of magnetic material, such as a magnet capable of exerting an attractive force on any ferromagnetic material.

[0105] The elastomeric element 4 comprises, in this case, ferromagnetic particles, in order to be attracted by the magnet 23.

[0106] The magnet 23 is configured to grip the elastomeric element 4 from above, i.e. its upper surface 4a and in particular a lateral edge 4b of said elastomeric element 4.

[0107] The magnet 23 preferably comprises a contact surface with the elastomeric element 4 having a surface roughness of between 6.3 and 12.5 Ra, in order to increase the coefficient of friction on said surface of the magnet 23.

[0108] Alternatively, any actuator capable of moving the gripping element 23 in translation along the vertical axis Z inside the housing 22 could be provided.

[0109] The first actuator is controlled by the ECU 40.

[0110] [Fig.5] illustrates the elastomeric element 4 in a position gripped by the gripping member 20. In this gripped position, the magnetization surface of the magnet 23 is parallel to the elastomeric element 4 and in particular to its upper surface 4a.

[0111] As illustrated, the locking member 30 comprises a locking finger 31 movable in rotation about an axis 32 between an unlocked position of the gripped elastomeric element 4, visible in FIGS. 2 to 5 and a locked position of the gripped elastomeric element 4, visible in FIGS. 6 and 7, in which the locking finger 31 is configured to apply a force along the gripping axis on a lower surface 4c of the gripped elastomeric element 4.

[0112] The axis 32 is parallel to the longitudinal axis X and perpendicular to the gripping axis.

[0113] The axis 32 is integral with the casing 21 of the gripping member 20.

[0114] The locking finger 31 is connected to a toothed wheel 33 or pinion which can rotate around the tilting axis 32 and is configured to mesh with a rack 34, or more generally a rod extending along the vertical axis Z and provided with notches 34a.

[0115] The upper end 34a of the rack 34 is secured to a connecting member 35 extending here perpendicular to the rack 34.

[0116] The connecting member 35 is connected to a second actuator 36, here a pneumatic cylinder comprising a cylinder rod 36a connected to the connecting member 35 and configured to move in translation along the vertical axis Z and drive the rack 34 in translation.

[0117] Generally, any actuator capable of moving the rack 34 in translation along the vertical axis Z could be provided.

[0118] The locking finger 31 is integral with the pinion 33, so that during the translation of the rack 34 along the axis Z, downwards, the pinion 33 meshes with the notches 34a of said rack 34, which generates a rotational movement of the locking finger 31 around the axis 32.

[0119] As illustrated, the locking finger 31 comprises a first portion 31a whose free end is secured to the pinion 33, and a second portion 31b connected to the first portion 31a by an elbow 31c. The first and second portions 31a, 31b extend along two axes forming an angle between 100° and 80° between them, preferably equal to 90°.

[0120] The second portion 31b comprises a free end 31d comprising a boss extending in a direction perpendicular to the second portion 31b and forming a contact surface with the elastomeric element 4 in the locked position of said elastomeric element 4.

[0121] The locking finger 31 is a single-piece part directly connected to a single tilting axis 32 relative to the gripping member 20.

[0122] The second actuator 36 is controlled by the ECU 40.

[0123] Alternatively, several locking fingers could be provided arranged in series on the same line only on the side of the edge 4b of the elastomeric element 4.

[0124] The installation comprises a first three-dimensional camera (not shown), such as an RGB-D sensor, restoring a cloud of points of coordinates measured in a frame associated with said first camera and having a line of sight oriented towards the elastomeric element 4 and configured to acquire an image of the elastomeric element 4. This step corresponds to a step 101 of acquiring the image of the elastomeric element 4. The first 3D camera is, preferably, fixed to a gantry and directed upstream towards the elastomeric element 4.

[0125] The first 3D camera makes it possible to avoid the necessary recalibration when using a 2D camera. Indeed, the first 3D camera will immediately bring the distance of the object and its perceived size into coincidence, which makes it possible to measure the dimensions of the object without having to indicate the depth at which it is located in relation to the camera.

[0126] Alternatively, it could be provided that the first camera is a 2D camera.

[0127] The electronic control unit UCE 40 comprises for this purpose a module 50 for gripping an edge of the end part 1a of the elastomeric element 4.

[0128] The gripping module 50 comprises a module 51 for acquiring the image of the elastomeric element 4 by the first 3D camera and a module 52 for processing the 3D image and determining a gripping point of the elastomeric element 4 using an image processing processor.

[0129] The image processing processor is configured to determine a gripping point of the elastomeric element 4 tangentially to the edge of the elastomeric element 4 at a distance of between 1mm and 5mm (to be confirmed) from the start of the edge of the elastomeric element 4.

[0130] For this purpose, the image processing processor is configured to detect an edge 4b of the elastomeric element 4 by the first 3D camera, for example, an RGB-D sensor, and to recover three-dimensional points belonging to the edge of the elastomeric element 4.

[0131] The image processing processor is further configured to approximate the edge 4b of the elastomeric element 4, search for a point of tangency of said edge 4b, evaluate the reference mark of the point of tangency and determine the center of the gripping member 20 as a function of the point of tangency.

[0132] The grip point is then transmitted to the robotic arm

[0133] The electronic control unit UCE 40 further comprises a module 53 for controlling the first actuator of the gripping member 20 and a module 54 for controlling the second actuator 36 of the locking member 30.

[0134] The gripping system 10 makes it possible to press the elastomeric element 4 as close as possible to the cut during a welding step in order to bring the cut ends of the elastomeric element 4 together. The welding step is carried out by a succession of gripping and releasing the gripped object along the tangential edge of the gripped object and by rotating the drum.

[0135] The installation comprises an assembly 80 comprising the gripping system 10 and the object 4 to be grasped.

[0136] As illustrated in [Fig.12], the assembly 80 further comprises a system 90 for holding the object in position during the welding step.

[0137] Indeed, due to the flexibility of the grasped object, it tends to return to its initial position after stopping a stress exerted, so that when the gripping member 10 comes to pull on the object to be grasped to place it as close as possible to the cup, it tends to return to its initial position once the gripping member 10 releases it.

[0138] The position holding system 90 is thus configured to apply pressure to the grasped object before release by the gripping member 10.

[0139] The position holding system 90 makes it possible to combat an elastic return of the plated object.

[0140] The flowchart illustrated in [Fig. 13] illustrates the successive steps of a method 100 for handling the elastomeric element 4 by the gripping system 10 with reference to FIGS. 2 to 7.

[0141] The gripping point of the elastomeric element 4 is determined, during a first step 101, by the module 51 for acquiring the image of the elastomeric element 4 by the first 3D or 2D camera and by the module 52 for processing the 3D or 2D image.

[0142] Once the gripping point has been determined, the gripping system 10 is positioned, during step 102, above the edge 4b of the elastomeric element 4, in an initial position, visible in [Fig.3].

[0143] During step 103, the gripping member 20 is brought closer to the outer surface 4a of the elastomeric element 4 until it comes into vertical contact with said outer surface 4a, visible in [Fig. 4]. In this position, the magnet 23 is in the high position, at a distance or air gap from the upper surface 4a of the elastomeric element 4 rendering the attractive force of the magnet 23 inoperative.

[0144] During step 104, the first actuator of the gripping member 20 is controlled in order to reduce the air gap of the magnet 23, that is to say to bring it closer to the outer surface 4a of the elastomeric element 4, as visible in [Fig. 5] in the gripped position of the elastomeric element 4.

[0145] During step 105, the gripping member 20 is actuated in order to vertically move the elastomeric element 4 into the gripped position by a predetermined height, between 20mm and 30mm, for example equal to 25mm, as visible in [Fig.6]. During this step 105, the locking finger 31 is tilted into the locked position around the axis 32 and comes into point contact with the lower surface 4c of the elastomeric element 4.

[0146] In the locked position, the point contact of the locking finger 31 with the lower surface of the elastomeric element 4 is located in the magnetization axis of the gripping member 20, i.e. normal to the elastomeric element 4.

[0147] In the locked position, the elastomeric element 4 is sandwiched between the magnet 23 and the locking finger 31.

[0148] The combination of the locking finger 31 and the magnet 23 makes it possible to transmit a tangential force of between 6daN and 10daN, for example equal to 8daN.

[0149] The vertical displacement of the elastomeric element 4 in the grasped position by a predetermined height makes it possible to free up sufficient space for the locking finger 31 to tilt into the locked position. Alternatively, provision could be made not to move the elastomeric element 4 before the locking finger 31 tilts.

[0150] During step 106, the gripping member 20 is actuated in order to vertically move the elastomeric element 4 into the gripped position as visible in [Fig.7]

[0151] The release of the elastomeric element 4 is carried out in three steps, the gripping system 10 is moved into a depositing position, preferably increased by the predetermined height provided in step 105, the locking finger 31 is tilted into the unlocked position, and the magnet 23 is moved in translation so as to increase the air gap with the surface 4a of the elastomeric element 4.

[0152] During a welding step (not visible in [Fig. 13]) and before releasing or freeing the object 4 gripped by the gripping system 10, a force is exerted on the gripped object 4 by the system 90 for holding the object in position.

[0153] The embodiment illustrated in Figures 8 to 11, in which the same elements bear the same references, differs from the previous embodiment only in that the gripping element 25 comprises a suction cup 26 and a magnet 23. Alternatively, only a suction cup 26 could be provided as a gripping element in the case where the elastomeric element 4 does not comprise ferromagnetic particles.

[0154] As illustrated in detail in Figures 10 and 11, the suction cup 26 comprises a generally cylindrical body 26a and a flexible skirt 26b extending from the body 26a obliquely outwardly.

[0155] The flexible skirt 26b is configured to come into contact with the upper surface 4a of the elastomeric element 4 in the gripped position, visible in [Fig.9].

[0156] The gripping element 25 is connected to the casing 21 of the gripping member 20 by a hollow vertical rod 27 intended to receive a flow of air for the actuation or detachment of the suction cup 26.

[0157] The vertical rod 27 is made integral with the gripping element by screw elements forming a lower stud 28 located inside said suction cup 26.

[0158] The lower pad 28 is in contact with the upper surface 4a of the elastomeric element in the gripped position and receives the force exerted by the locking finger 31 in the locked position.

[0159] The gripping system 10 according to the invention is dedicated to the handling of flexible and thin parts and makes it possible to couple two actions, gripping from above with a magnet and / or a suction cup and reliable holding by means of a movable finger.

[0160] Top gripping is particularly suitable for robotics situations where the robotic arm operates in a constrained environment and where vision can only be obtained from above the element to be gripped.

[0161] The gripping system 10 according to the invention allows the handling of parts flexible, reinforced or not with metal cables, which are too flexible to be handled by a single magnet or too textured to be handled by a single suction cup.

[0162] The finger ensures gripping once detachment has been achieved. In addition, the finger prevents the object from slipping once in contact with the gripping member.

[0163] Finally, the gripping system has a load capacity and positioning rigor significantly improved compared to known solutions.

[0164] The gripping system and the handling method according to the invention is designed to adapt to both existing manual installations and new installations.

Claims

Claims

1. A system (10) for gripping an object (4) comprising a gripping member (20) configured to grip an upper surface (4a) of the object (4) along a gripping axis and a locking member (30) configured to lock the object (4) in the position gripped by the gripping member (20), characterized in that the locking member (30) comprises at least one locking finger (31) in one piece and movable in rotation about a single tilting axis (32) integral with the gripping member (20) between an unlocked position and a locked position of the object (4) gripped by the gripping member (20) in which the locking finger (31) is configured to apply a force along the gripping axis to a lower surface (4c) of the gripped object (4).

2. Gripping system (10) according to claim 1, wherein the gripping member (20) comprises a gripping element (23, 25, 26) configured to exert an attractive force on the object (4) along the gripping axis.

3. Gripping system (10) according to claim 1 or 2, in which the locking member (30) comprises a pinion (33) integral with the locking finger (31) and movable in rotation about the tilting axis (32) and a rod (34) extending along the gripping axis and provided with notches (34a) configured to cooperate with the pinion (33) when the locking finger (31) moves from the locked position to the unlocked position.

4. Gripping system (10) according to claim 3, wherein the locking member (30) comprises a second actuator (36) connected to the rod (34) and configured to move said rod (34) in translation along the gripping axis.

5. Gripping system (10) according to any one of the preceding claims, in which the locking finger (31) comprises a first portion (31a) whose free end is integral with the pinion (33), and a second portion (31b) connected to the first portion (31a) by an elbow (31c).

6. Gripping system (10) according to claim 5, wherein the second portion (31b) comprises a free end (31d) comprising a boss extending in a direction perpendicular to the second portion (31b) and forming a contact surface with the object (4) in the locked position of said object (4).

7. A gripping system (10) according to any preceding claim, wherein the tilting axis (32) of the locking finger (31) is perpendicular to the gripping axis.

8. A gripping system (10) according to any preceding claim, comprising a plurality of locking fingers (31) arranged in series on a single line only on one side.

9. Gripping system (10) according to claim 2 taken in combination with any one of the preceding claims, wherein the gripping element (23, 25, 26) is an element of magnetic material (23) and / or a suction cup (26).

10. Gripping system (10) according to claim 9, wherein when the gripping element (23) is an element made of magnetic material, its contact surface with the object (4) has a surface roughness of between 6.3 and 80 Ra.

11. A gripping system (10) according to claim 9, wherein when the gripping element (23, 25, 26) comprises at least one suction cup (26), said suction cup (26) comprising a generally cylindrical body (26a) and a flexible skirt (26b) extending from the body (26a) obliquely outwards and configured to come into contact with the upper surface (4a) of the object (4) in the gripped position.

12. Gripping system (10) according to any one of the preceding claims, in which the gripping member (20) comprises a casing (21) secured to a connecting interface (11) with the robotic arm.

13. Gripping system (10) according to claim 12, wherein the casing (21) comprises an internal housing (22) for receiving a first actuator configured to move the gripping element in translation along the gripping axis inside the housing.

14. Gripping system (10) according to claim 11 in combination with any one of claims 12 and 13, wherein the suction cup (26) is connected to the casing (21) of the gripping member (20) by a hollow vertical rod (27) intended to receive a flow of air for the actuation or detachment of the suction cup (26), said vertical rod (27) being secured to the gripping element (26) by screw elements forming a lower stud (28) located inside said suction cup (26), the lower stud (28) being configured to be in contact with the upper surface (4a) of the object (4) in the gripped position and to receive the force exerted by the locking finger (31) in the locked position.

15. Gripping system (10) according to any one of the preceding claims, comprising an electronic control unit (40) comprising a module (50) for gripping an edge (4b) of the end portion of the object (4), a module (53) for controlling the gripping member (20) and a module (54) for controlling the locking member (30).

16. An assembly (80) comprising a gripping system (10) according to any one of the preceding claims and an object (4) to be gripped.

17. An assembly (80) according to claim 16, wherein the object (4) is an elastomeric element.

18. Assembly (80) according to claim 16 or 17, comprising a system (90) for holding the object in position during a welding step configured to apply pressure to the object (4) gripped before release by the gripping member (10).

19. Installation for manufacturing tire blanks from at least one elastomeric element (4) and comprising at least one robotic arm, an electronic control unit (40) configured to control the robotic arm, a laying station comprising a drum for manufacturing tire blanks and at least one first three-dimensional camera restoring a cloud of points of coordinates measured in a reference frame associated with said first camera and having a sighting axis oriented towards the elastomeric element (4) to be grasped and configured to acquire an image of the elastomeric element (4) to be grasped, the installation comprising at least one gripping system (10) according to any one of the preceding claims secured to the robotic arm.

20. Method (100) for handling an object (4) by a gripping system (10) for gripping an object (4) comprising a gripping member (20) configured to grip an upper surface (4a) of the object (4) along a gripping axis and a locking member (30) configured to lock the object (4) in the position gripped by the gripping member (20), the locking member (30) comprising at least one locking finger (31) in one piece and movable in rotation about a single tilting axis (32) secured to the gripping member (20) between an unlocked gripped position and a locked position of the object (4) gripped by the gripping member (20) in which the locking finger (31) is configured to apply a force along the gripping axis to a lower surface (4c) of the gripped object (4), comprising the steps successive following: - positioning of the gripping system (10) above the edge (4b) of the object (4) to be grasped, - translational movement along the gripping axis of the gripping member (20) of the outer surface (4a) of the object (4) until it comes into vertical contact with said outer surface (4a), - tilting of the locking finger (31) around the tilting axis (32) into the locked position in which said locking finger (31) is in point contact with the lower surface (4c) of the object (4) along the gripping axis.

21. Method (100) according to claim 20, wherein, before tilting the locking finger (31) into the locked position, a first actuator is actuated to actuate the attractive force of the gripping element (23, 25, 26).

22. Method (100) according to claim 20 or 21, in which, before positioning the gripping system (10) above the edge (4b) of the object (4) to be grasped, the gripping point of the object (4) is determined by a module (51) for acquiring the image of the object (4) by a first 3D camera and by a module (52) for processing the 3D image.

23. Method (100) according to any one of claims 20 to 22, in which, during a welding step and before releasing the object (4) gripped by the gripping system (10), a force is exerted on the gripped object (4) by a system (90) for holding the object in position.

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