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Title:
DEVICE FOR TURNING A PLY INTENDED FOR ASSEMBLING A GREEN TYRE
Document Type and Number:
WIPO Patent Application WO/2018/069065
Kind Code:
A1
Abstract:
The invention relates to a device (70) for turning over a ply (N) intended for the assembly of a green tyre, the ply (N) having a lower face (Fl) and an upper face (FS), the turning device comprising a first arrival table (72), a second receiving table (74), and a handling device (20) allowing a ply (N) to be transferred automatically from the arrival table to the receiving table using a gripping device (10). According to the invention, with the ply (N) resting on its lower face (Fl) on the arrival table (72), the receiving table (74) is higher up than the arrival table so as to create a step (76) that allows the turning device (70) to turn the ply (N) over quickly at the same time as it is being transferred from the arrival table (72) to the receiving table (74).

Inventors:
DETTORRE JEAN-MARIE (FR)
DRAGO FRÉDÉRIC (FR)
Application Number:
PCT/EP2017/074756
Publication Date:
April 19, 2018
Filing Date:
September 29, 2017
Export Citation:
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Assignee:
MICHELIN & CIE (FR)
International Classes:
B29D30/00
Domestic Patent References:
WO1998031621A11998-07-23
WO2016108884A12016-07-07
WO2015147637A12015-10-01
Foreign References:
US5758590A1998-06-02
US3866774A1975-02-18
Other References:
None
Attorney, Agent or Firm:
DEQUIRE, Philippe (FR)
Download PDF:
Claims:
CLAIMS

1 . A device (70) for turning over a ply (N) made from a rubber composition and intended for the assembly of a green tyre for a vehicle wheel, the ply (N) having a lower face (Fl) and an upper face (FS), the turning device comprising a first table (72) on which a ply (N) that is to be turned arrives, a second table (74) on which a turned ply (N) is received, and a handling device (20) allowing a ply (N) to be transferred automatically from the arrival table to the receiving table using a gripper device (10), the turning device being characterized in that, with the ply (N) resting on its lower face (Fl) on the arrival table (72), the receiving table (74) is higher up than the arrival table so as to create a step (76) that allows the turning device (70) to turn the ply (N) over quickly at the same time as it is being transferred from the arrival table (72) to the receiving table (74), the ply (N) resting on its upper face (FS) on the receiving table (74) after it has been transferred.

2. A device (70) for turning a ply (N) according to claim 1 , in which the gripping device (10) allows the grasping only of an edge (B) of the ply (N) that is to be turned.

3. A device (70) for turning a ply (N) according to claim 2, in which the gripping device (10) comprises a plurality of gripper elements (12) for gripping a ply (N).

4. A device (70) for turning a ply (N) according to claim 3, in which the ply-gripper elements (12) are aligned.

5. A device (70) for turning a ply (N) according to claim 4, in which each gripper element (12) allows the ply (N) that is to be turned to be caught hold of locally.

6. A device (70) for turning a ply (N) according to claim 5, in which each gripper element (12) takes the form of a suction cup (14).

7. A device (70) for turning a ply (N) according to one of the preceding claims, in which the turning device comprises an inclined surface (78) between the arrival table (72) and the receiving table (74).

8. A device (70) for turning a ply (N) according to one of the preceding claims, in which the handling device (20) allows the gripping device (10) to be moved at least in a vertical direction (DV) perpendicular to the work surfaces (P72, P74) of the arrival table (72) and receiving table (74) and in a horizontal direction (DH) parallel to the work surfaces (P72, P74) of the arrival table (72) and receiving table (74).

9. A device (70) for turning a ply (N) according to claim 8, in which the handling device (20) allows the gripping device (10) to be made to pivot about a horizontal axis (AH) parallel to the work surfaces (P72, P74) of the arrival table (72) and receiving table (74) and perpendicular to the vertical direction (DV) perpendicular to the work surfaces (P72, P74) of the arrival table (72) and receiving table (74).

10. A device (70) for turning a ply (N) according to one of the preceding claims, the gripping device (10) comprising at least one gripper element (12), a connection base (18) for connecting to the handling device (20), and at least one structural element (40, 40") supporting each gripper element (12) and fixed to the connection base (18) or to another structural element (40'), in which each structural element (40, 40', 40") adopts the form of a bladder (50) inflated with at least one gas.

Description:
DEVICE FOR TURNING A PLY INTENDED FOR ASSEMBLING A GREEN TYRE

[001] The invention falls within the field of tyres and more precisely within the field of the manufacture of the plies used in the manufacture of green tyres. [002] More specifically, the invention relates to the manufacture of the carcass plies used for assembling green tyres. Such carcass plies take the form of a fine rubber profiled element incorporating transverse reinforcements that give the future tyre a radial carcass. In order to obtain such carcass plies, a first profiled element incorporating the reinforcements in its length is produced first of all, notably by applying skims using calendaring. Next, this first profiled element is cut into lengths along its width. These lengths form plies which are turned over so that their upper and lower faces can be visually inspected. The turned plies are then butted together to form a second profiled element incorporating the reinforcements in its width and from which lengths intended to form the carcass plies of future tyres will be taken.

[003] Previously, the plies were turned by hand and this could prove tiring or even injurious to the operators, more because of the repetitive nature of the task and the amplitude of the movement than because of the mass of these plies which weigh only a few hundred grams.

[004] Thus, the object of the present invention is to collaboratively automate the turning- over of a ply intended for assembling a green tyre in the vicinity of an operator. [005] To this end, one object of the invention is a device for turning a ply made from a rubber composition, the ply having a lower face and an upper face, the turning device comprising a first table on which a ply that is to be turned arrives, a second table on which a turned ply is received, and a handling device allowing a ply to be transferred automatically from the arrival table to the receiving table using a gripper device. [006] According to the invention, with the ply resting on its lower face on the arrival table, the receiving table is higher up than the arrival table so as to create a step that allows the turning device to turn the ply over quickly at the same time as it is being transferred from the arrival table to the receiving table, the ply resting on its upper face on the receiving table after it has been transferred. [007] Advantageously, the step present between the two tables makes it possible to simplify and shorten the movement performed by the gripper device to turn the ply over. As a result, the step allows the plies to be turned over quickly between the two tables. [008] In addition, by forming a linear stop against which the ply comes into abutment, the step makes it possible to ensure that the ply is turned over.

[009] Finally, the collaborative aspect of the turning device is obtained because of the non-dangerous nature of the structural element or elements of the gripping device. [010] Further features and advantages of the invention will become apparent from the following description. This description, which is given by way of non-limiting example, refers to the appended drawings, in which:

Figure 1 is a perspective view of a first alternative form of a gripping device according to the invention, - Figure 2 is a perspective view of a first alternative form of a gripping device according to the invention, mounted on a robot arm,

Figure 3 is a perspective view of a second alternative form of a gripping device according to the invention,

Figure 4 is a perspective view of a third alternative form of a gripping device according to the invention,

Figure 5 is a perspective view of a ply turning device according to the invention, and

Figures 6A to 6D illustrate the turning of a ply using a ply turning device according to the invention.

[011] As illustrated in Figures 1 and 2, the invention relates to the gripping of an object using a gripping device 10. As illustrated in Figures 5 and 6A to 6D, in one application of particular interest to the Applicants, this object may be a ply N made from a rubber composition and intended for the assembly of a green tyre for a vehicle wheel.

[012] In order to allow an object or any load to be transported from one location to another, the gripping device 10 comprises at least one gripper element 12 for gripping this object. This gripper element 12 may adopt various forms, but for the purposes of transporting a ply N intended for assembling a green tyre, the gripper element 12 preferably adopts the form of a suction cup 14. A suction cup 14 comprises a flexible and deformable membrane 16 intended to be pressed against the object that is to be transported and then placed under suction so as to adhere to the object that is to be transported. [013] Again in order to allow an object or any load to be transported from one location to another, the gripping device 10 includes a connection base 18 for connection to an automated handling device 20 such as, for example, a robot arm like the one illustrated in Figure 2. Such a handling device 20 is capable of moving the gripping device 10, and therefore the object or load being transported, at least about and/or along a handling axis, and preferably about and/or along various handling axes.

[014] In the example depicted in Figure 2, the handling device 20 comprises a lower arm 22, an upper arm 24 and a mount 26. The lower arm 22 is articulated with respect to the mount 26, the upper arm 24 is articulated with respect to the lower arm 22, and the gripping device 10 is articulated with respect to the upper arm 24. [015] More specifically, the lower arm 22 is articulated for rotation with respect to the mount 26 about a vertical axis AV and about a horizontal axis AH, the upper arm 24 is articulated to rotate with respect to the lower arm 22 about an intermediate axis Al, and the gripping device 10 is articulated to rotate with respect to the upper arm 24 about three mutually perpendicular axes A1 , A2, A3. For preference, an electric motor 28 drives the lower arm 22 in rotation with respect to the mount 26 and about the vertical axis AV and another electric motor 30 drives the lower arm 22 in rotation with respect to the mount 26 and about the horizontal axis AH. Next, another electric motor 32 drives the upper arm 24 in rotation with respect to the lower arm 22 about the intermediate axis Al. Finally, three other electric motors 34, 36, 38 drive the gripping device 10 in rotation with respect to the upper arm 24 about the three perpendicular axes A1 , A2 and A3 respectively.

[016] In this configuration, the handling device 20 offers a six-axis architecture referred to as anthropomorphic. Of course, depending on the use made of the gripping device 10 and on the layout of the workstation, the handling device 20 may adopt other architectures with more or fewer axes of mobility. [017] In order to support each gripper element 12, the gripping device 10 includes at least one structural element 40. In the various alternative forms of the gripping device 10, at least one structural element 40 is fixed to the connection base 18.

[018] In a first alternative form illustrated in Figures 1 and 2, the gripping device 10 includes a single structural element 40 fixed to a connection base 18, and taking the form of a mounting plate 42.

[019] In a second alternative form illustrated in Figure 3, the gripping device 10 includes two structural elements 40 fixed to a connection base 18 and taking the form of a mounting frame 44. For preference, the two structural elements 40 run parallel to one another so as to allow the gripping device 10 to handle objects of a larger size, notably plies N of greater width.

[020] Finally, in a third alternative form illustrated in Figure 4, the gripping device 10 includes a main structural element 40' fixed to a connection base 18 and adopting the form of a mounting plate 42, and a plurality of secondary structural elements 40" fixed to the main structural element 40'. Again with a view to allowing the gripping device 10 to handle objects of greater size, the secondary structural elements 40" extend at right angles to the main structural element 40'.

[021] In order to make the gripping device 10 as free of danger as possible, each structural element 40, 40', 40" takes the form of a bladder 50 inflated with at least one gas. A bladder 50 may be inflated with air or with a specific gas, such as a gas that is lighter than air for example.

[022] Advantageously as regards the safety of the operator working in the vicinity of the gripping device 10 and of its robot arm, the rigidity of the bladder 50 is obtained only by the pressure of the air or of the gas contained within this bladder 50, and therefore without the use of a reinforcement, a core and/or reinforcements that are rigid

[023] As an indication, the pressure of the air or of the gas inside a bladder 50 is of the order of 0.2 to 0.4 bar. This low pressure is enough to transport objects or loads of a mass ranging up to 5 kg, and avoids making the bladder 50 too rigid and therefore dangerous in the event of its collision with an operator.

[024] In order to contain the air or the gas in a fluid-tight manner, the bladder is preferably made of PVC (polyvinyl chloride) with a mass per unit area of 850 g/m 2 . This material also offers the advantage of deforming, allowing it both to withstand potential collisions with another object and making it possible to avoid injuring an operator in a collision.

[025] Again with a view to maximizing the safety of an operator situated in the vicinity of the gripping device 10, a bladder 50 has rounded ends 52, 54. What the invention means by rounded is ends 52, 54 that are substantially hemispherical.

[026] For the same reason, and also to make a bladder 50 easier to produce, each bladder 50 is cylindrical.

[027] In order to handle objects extending lengthwise over several tens of centimetres, such as, for example, plies N intended for assembling green tyres, each bladder 50 is of elongate shape. Thus, a bladder 50 supports several gripper elements 12.

[028] In order to handle objects extending lengthwise and widthwise over several tens of centimetres, such as, for example, plies N intended for assembling green tyres, each bladder 50 is of elongate shape. [029] The first alternative form of the gripping device 10 comprising a single bladder 50 of elongate shape, is very well-suited to instances in which the object that is to be transported extends only lengthwise or in which the object that is to be transported extends both lengthwise and widthwise but needs to be grasped only by one of its longitudinal or transverse edges. [030] The second and third alternative forms of the gripping device 10 comprising several parallel bladders 50 are more suitable in instances in which the object that is to be transported extends both lengthwise and widthwise and in which this object needs to be grasped both on its length and on its width.

[031] In the various alternative forms of the gripping device 10, flexible collars 56 are used to fix a bladder 50 to the connection base 18 or to fix two bladders 50 to one another. These flexible collars 56 are also used to fix the gripper elements 12 to a bladder 50. These flexible collars 56 may be made of metal, of fabric, or of plastic.

[032] In order to simplify the installation and use of the gripping device 10 on an industrial site, the gripping device 10 carries an on-board device 60 for creating a vacuum from a source of compressed air. Advantageously, the compressed air is supplied to the device 60 via the compressed-air circuit 62 usually present on industrial sites. This device 60 is intended to be connected to each of the suction cups 14 to allow them to adhere to the object that is to be transported. For preference, the device 60 is supported by the mounting plate 42 or the frame 44 of the connection base 18. By way of example, in being supplied with air or a gas at a pressure of 6 bar, the device 60 enable the creation of suction of 0.2 to 0.5 bar.

[033] In addition to the danger-free nature of the structural elements 40, 40', 40", the handling device 20 and/or the gripping device 10 may be equipped with means aimed at detecting, and potentially at anticipating, any impact or collision of an object or an operator with the handling device 20 and/or with the gripping device 10 in order to halt the movements of the handling device 20 and of the gripping device 10 as quickly as possible.

[034] First of all, the handling device 20 may be equipped with means that measure the load supplied by its actuator or actuators, such as, for example, the torque supplied by the electric motors 28,30,32,34,36,38, and capable of detecting a sudden variation in this load which corresponds to an impact or a collision.

[035] Next, the handling device 20 and/or for preference the gripping device 10 may be fitted with means for detecting a collision with an object or with an operator. These detection means preferably adopt the form of proximity sensors of capacitive type making it possible to detect non-metallic objects and, therefore, an operator.

[036] Thus, at least one proximity sensor 90 of capacitive type is arranged on a structural element 40, 40', 40" adopting the form of a bladder 50. However, for preference, and as illustrated in Figure 1 , a network of several proximity sensors 90 of capacitive type is installed on the structural element or elements 40, 40', 40" of the gripping device 10.

[037] Advantageously, when proximity sensors 90 of capacitive type are arranged on a structural element 40, 40', 40" adopting the form of a bladder 50 inflated with air or with gas, their operation, and notably their detection range, is improved. Specifically, by being positioned in this way, the sensors are sufficiently distant from any metallic mass, from any electrical connection or from any electrical device such as a motor of the handling device 20 liable to perturb their operation, and more particularly, the electrical field that they emit.

[038] As illustrated in Figures 5 and 6A to 6D, the invention also relates to a device 70 for turning over a ply N made from a rubber composition and intended for the assembly of a green tyre for a vehicle wheel. This turning device 70 is intended to work collaboratively in the vicinity of an operator O.

[039] What the invention means by a ply N is a thin, substantially rectangular object that is made of a raw rubber mix, i.e., not cross-linked, that can incorporate reinforcements arranged parallel to one another and that are oriented lengthwise or widthwise in the ply, or inclined at a given angle with respect to the longitudinal and transverse directions of the ply. For example, a ply N has a thickness of around 1 mm, a width of several tens of centimetres, and a length that is greater than its width.

[040] Also, such a ply N essentially has a lower face Fl and an upper face FS.

[041] In order to perform the turning, the turning device 70 comprises a first table 72 on which a ply N that is to be turned arrives, a second table 74 on which a turned ply N is received, and a handling device 20 allowing a ply N to be transferred automatically from the arrival table to the receiving table using a gripping device 10.

[042] Advantageously, with the ply N resting on its lower face Fl on the arrival table 72, the receiving table 74 is higher up than the arrival table so as to create a step 76 that allows the turning device 70 to turn the ply N over quickly at the same time as it is being transferred from the arrival table 72 to the receiving table 74. After it has been transferred, the turned ply N rests on its upper face FS on the receiving table 74. [043] More specifically, the step 76 forms a linear stop against which the ply N comes into abutment so that it can be turned over.

[044] By virtue of the step 76, the turning device 70 offers a simplified design avoiding the use of a second gripping device to grasp hold of the lower face Fl of the ply N and complete the turning-over of the ply N. [045] For preference, in order to ensure that the ply N is turned over, the step 76 has a height H76 of between one-quarter and one-half of the width LN of the ply N that is to be turned. In the case of plies that are intended for the assembly of green tyres of the passenger vehicle type, the step 76 has a height H76 of around twenty-five centimetres.

[046] For preference, the turning device 70 incorporates the first alternative form of the gripping device 10 in which form a single bladder 50 of elongate shape supports several aligned gripper elements 12.

[047] In this first alternative form, the gripping device 10 allows the grasping of only one edge B of the ply N that is to be turned. The edge B grasped is preferably a longitudinal edge BL because the turning of the ply N using the step 76 needs to be performed by a movement of the ply N performed chiefly in a horizontal direction DH parallel to the transverse direction of the ply N.

[048] Because of the length of a ply N, the gripping device 10 of the turning device 70 preferably comprises a plurality of ply-gripping elements 12.

[049] In addition, as the objective is to grasp the ply only via one of its edges B, the gripper elements 12 of the turning device 70 are aligned.

[050] Because of the low mass of a ply and in order to limit the energy consumed during the turning, each gripper element 12 of the turning device 70 allows the ply that is to be turned to be grasped locally, namely over a surface area measuring a few square centimetres.

[051] For preference, each gripper element 12 of the turning device 70 takes the form of a suction cup 14, suction cups 14 offering the advantage of not puncturing or impairing the surface finish of the plies N transported.

[052] Again for preference, the turning device 70 comprises an inclined surface 78 between the arrival table 72 and the receiving table 74. Inclined, for example, at 45°, this inclined surface 78 makes it possible to ensure that the ply N is not damaged as it is turned over.

[053] As shown in Figures 6A to 6D, the handling device 20 allows the gripping device 10 to be moved at least in a vertical direction DV perpendicular to the work surfaces P72 and P74 of the arrival table 72 and receiving table 74 and in a horizontal direction DH parallel to the work surfaces P72 and P74 of the arrival table 72 and receiving table 74. [054] However, for preference, the handling device 20 also allows the gripping device 10 to be made to pivot about a horizontal axis AH parallel to the work surfaces P72 and P74 of the arrival table 72 and receiving table 74 and perpendicular to the vertical direction DV perpendicular to the work surfaces P72 and P74 of the arrival table 72 and receiving table 74. [055] Figure 6A illustrates a first step of the turning in which step the gripping device 10 grasps hold of a longitudinal edge BL of the ply N with its gripper elements 12, namely four aligned suction cups 14 spaced apart and placed under suction.

[056] In a second step of the turning, which step is illustrated in Figure 6B, the handling device 20 moves the gripping device 10 upwards in the vertical direction DV so as to lift the longitudinal edge BL of the ply N grasped by the gripper elements 12.

[057] It is more particularly during the third step illustrated in Figure 6C that the turning- over of the ply occurs. To this end, the handling device 20 moves the gripping device 10 in the horizontal direction DH and from the arrival table 72 towards the receiving table 74. In parallel with this movement in the horizontal direction DH, the handling device 20 causes the gripping device 10 to pivot through approximately 90° about the horizontal axis AH so as to prevent the ply N from folding over onto itself and so as to place the gripping device 10 into a position suitable for releasing the turned ply N on the receiving table 74.

[058] In order to release the turned ply N which is illustrated in Figure 6D, the handling device 20 moves the gripping device 10 again in the horizontal direction DH and from the arrival table 72 towards the receiving table 74, and it also moves the gripping device 10 downwards in the vertical direction DV so as to bring the gripping device 10 and its gripper elements 12 as close as possible to the work surface P74 of the receiving table. [059] Thanks to the turning device 70, the operator no longer has to perform the repetitive movements associated with manual turning. Thus, the operator has more time to visually inspect the lower faces Fl and the upper faces FS of the plies N and to perform a later step of butting together and assembling the rear transverse edge BTR of a first ply N turned by the turning device 70 with the front transverse edge BTF of a second ply N turned by the turning device 70.