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EP-4739472-A1 - SYSTEM FOR GRIPPING AN OBJECT, IN PARTICULAR AN ELASTOMERIC ELEMENT, METHOD FOR HANDLING SAID OBJECT AND INSTALLATION FOR MANUFACTURING GREEN TYRES

EP4739472A1EP 4739472 A1EP4739472 A1EP 4739472A1EP-4739472-A1

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 an axis of gripping 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 one-piece locking finger (31) that can rotate about a single pivot (32) secured to the gripping member (20) between a gripped 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 axis of gripping to a lower surface (4c) of the gripped object (4).

Inventors

  • DRUET, MICHEL
  • DA-COSTA, Fabrice
  • ROCA-FILELLA, Nicolas
  • BARD, Nicolas
  • THOMANN, Etienne

Assignees

  • COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN

Dates

Publication Date
20260513
Application Date
20240701

Claims (20)

  1. 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) secured to 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. 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. 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 passing from the locked position to the unlocked position of the locking finger (31).
  4. 4. Gripping system (10) according to claim 3, in which 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. 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 of the pinion (33), and a second portion (31b) connected to the first portion (31a) by an elbow (31c).
  6. 6. Gripping system (10) according to claim 5, in which 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. 7. Gripping system (10) according to any one of the preceding claims, in which the tilting axis (32) of the locking finger (31) is perpendicular to the gripping axis.
  8. 8. Gripping system (10) according to any one of the preceding claims, comprising a plurality of locking fingers (31) arranged in series on the same line only on one side.
  9. 9. Gripping system (10) according to claim 2 taken in combination with any one of the preceding claims, in which the gripping element (23, 25, 26) is an element made of magnetic material (23) and/or a suction cup (26).
  10. 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. 1 1. 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. 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 connection interface (11) with the robotic arm.
  13. 13. Gripping system (10) according to claim 12, in which the casing (21) comprises an internal housing (22) for receiving a first actuator configured to move in translation along the gripping axis the gripping element inside the housing.
  14. 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 an air flow for the actuation or detachment of the suction cup (26), said vertical rod (27) being integral with 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. 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 part of the object (4), a module (53) for controlling the gripping member (20) and a module (54) for controlling the locking member (30).
  16. 16. Assembly (80) comprising a gripping system (10) according to any one of the preceding claims and an object (4) to be grasped.
  17. 17. Assembly (80) according to claim 16, in which the object (4) is an elastomeric element.
  18. 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. 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 frame associated with said first camera and having a line of sight 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. 20. Method (100) for handling an object (4) by a gripping system (10) of 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) integral with 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 on a lower surface (4c) of the object (4) seized, comprising the following successive steps: - 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.

Description

DESCRIPTION TITLE: System for gripping an object, in particular an elastomeric element, method for handling said object and installation for manufacturing tire blanks The present invention relates to the field of gripping an object, particularly one of low thickness. More particularly, the present invention relates to the gripping of strips or sheets, in particular in the manufacture of tire blanks. The invention also relates to a method for gripping strips or plies of tire blanks during the manufacture of the blank. 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. The tire further comprises a metal or textile fiber structure forming a reinforcing carcass for the tire structure and connecting the crown to the beads. To manufacture a tire blank, elements in the form of bead wires, strips or plies are successively assembled to form a cylindrical carcass reinforcement. The cylindrical carcass reinforcement is then transformed into a toroidal carcass reinforcement, during a step known as "conformation". During this step, the top of the cylindrical carcass reinforcement is stretched to increase the diameter and the beads are axially brought closer together. Finally, elements in the form of strips or plies are successively assembled on the top of the carcass reinforcement. layers so as to additionally form a crown reinforcement and a tread. The assembly and conformation steps are generally carried out on a cylindrical tire blank manufacturing drum, rotating around 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 installation steps are carried out manually or automatically. 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 portion of the elastomeric element with the end portion anchored on the external surface of the drum. During the welding step, it is necessary to bring the cut ends of the elastomeric element closer together. It is then necessary to grasp one cut end of the elastomeric element. We can refer to figure 1 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 1 mm to 5 mm and elastically deformable, such as an elastomeric element. However, due to its flexibility, the object 3 can deform when grasped from above and break the connection with the gripping system 1, as visible in figure 1. We then observe a detachment of object 3. Gripping systems with retractable clamps are also known. In this regard, reference may be made to document CN 1 13400331 - A. However, such a solution does not allow a surface object to be gripped by an edge. Also known is document WO 2020142464 - Al which describes a robotic end effector comprising a magnet surface and a plurality of movable fingers defining with the magnet surface a space for gripping a large rigid three-dimensional object. 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 that is not compatible with the use of robots in the manufacture of tire blanks. We also know of gripping systems using a suction cup to manipulate an object. However, the flexibility and/or texture of the object can cause it to sag and open the support surface, which results in a loss of support effectiveness or even total loss of the support function. Current gripping systems cannot reliably handle the edge of a thin, flexible object. Thus, there is a need to remedy the aforementioned drawbacks. The invention aims to improve the gripping systems for flexible and thin objects, such as an elastomeric element used in the manufacture of tire blanks. The present invention relates to 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 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. The gripping system according to the invention is dedicated to the handling of flexible and thin parts and makes it possible to couple two