METHOD AND GRIPPING APPARATUS FOR GRABBING AN ANNULAR TIRE STRUCTURE.

Abstract

A gripping apparatus for gripping an annular tire structure (100) comprises a support structure (2) carrying at least two shoes (3) and a plurality of sensors (5) carried by the shoes (3) and distributed circumferentially around a gripping axis (X). Each sensor (5) has a contact area (6) corresponding to a portion of the sensor (5) facing the gripping axis (X). Each shoe (3) comprises at least two sensors (5) and an adjustment device (8) configured to adjust the relative position of the sensors (5). A movement group (4) is operatively interposed between the support structure (2) and the shoes (3) to close or open the shoes (3) relative to each other.

Description

METHOD AND GRIPPING APPARATUS FOR GRASPING AN ANNULAR STRUCTURE OF TIRE The present invention relates to a method for gripping an annular tire structure and a gripping apparatus for gripping an annular tire structure. A vehicle wheel tire generally comprises a casing structure comprising at least one casing layer with opposite ends respectively hooked with respective annular anchoring structures, integrated into the areas normally identified by the name of beads, with an inner diameter substantially corresponding to a so-called tire mounting diameter on a respective mounting rim. An airtight coating layer, usually called a liner, can cover the internal surfaces of the casing structure and, therefore, the tire. The casing structure is associated with a belt structure that may comprise one or more belt layers, located radially overlapping each other and with respect to the casing layer, having metallic or textile reinforcing cords with transverse orientation and / or substantially parallel (at 0 degrees) with respect to the circumferential extension direction of the tire. Positioned radially outside the belt structure, a tread is applied, also made of elastomeric material like other constituent components of the tire. The respective sidewalls made of elastomeric material are also applied in an axially external position with respect to the lateral surfaces of the casing structure, each extending from one of the lateral edges of the tread to the respective annular anchoring structure on the beads. In a green tire construction process, the production of a casing sleeve and a so-called outer sleeve can be provided for separately. To make the casing sleeve, one or more layers of casing are applied to a forming drum. Anchoring ring structures are fitted or formed onto the fins at the opposite end of the casing layer(s), which are then twisted around the ring structures themselves to enclose them in a loop. Before the casing sleeve is fully constructed, at least a portion of the sidewalls may be applied over the casing layer(s). To make the outer sleeve, one or more layers of belt are applied on a second drum or auxiliary drum in radial overlap. The tread and possibly at least part of the sidewalls are applied radially external to the belt layer(s). The outer sleeve is collected from the auxiliary drum to couple it to the sleeve of the housing. The outer sleeve is arranged coaxially around the shell sleeve. Subsequently, the shell layer or layers are molded into a toroidal configuration by axially bringing the beads closer together and simultaneously introducing pressurized fluid into the shell sleeve, causing radial expansion of the shell layers against the radially internal surface of the outer sleeve. The assembly of the casing with the outer sleeve can be carried out on the same drum used to make the casing sleeve, in which case it is referred to as a one-stage construction process or single-stage process. There are also known two-stage construction processes, in which a so-called first-stage drum is used to make the casing sleeve, while the assembly between the casing sleeve and the outer sleeve is driven in a so-called second-stage drum or forming drum in which the casing sleeve is picked up from the first-stage drum and, subsequently, the outer sleeves picked up from the auxiliary drum are transferred. After the construction of the green tire, a molding and vulcanization treatment is carried out which aims to determine the structural stabilization of the tire through the crosslinking of the elastomeric compositions, as well as imparting to it, if requested, a desired tread design and possible distinctive graphic markings on the sidewalls of the tire. Therefore, at all stages of construction and / or vulcanization, a transfer of at least one annular structure of the tire is provided. The annular structure of a tire is understood to be an annular structure achieved during the construction process of a green tire, comprising one or more tire components and extending circumferentially around a tire axis that, with the tire vulcanized, coincides with the tire's axis of rotation. For example, the annular structure of the tire may be the casing sleeve, the outer sleeve, the green tire, or any annular portion thereof achieved during the relevant construction process. The gripping diameter of an annular tire structure refers to the outer diameter (maximum size) of said annular tire structure. The casing sleeve is intended to have at least one casing layer associated with the anchoring of annular structures. The outer sleeve is intended to have at least one or more layers of belt and tread. The tire axle is understood to be an axle that, in the vulcanized tire, corresponds to the axis of rotation of the tire itself and that, in the relative annular structure of the tire, corresponds to the axis around which the annular structure of the tire itself extends. The shoe is intended to be a movable element adapted to be contiguous against the radially outer surface of the annular structure of the tire in order to grip it. The sensor is intended to be a fixed or movable element of the shoe designed to come into contact with the radially outer surface of the tire's annular structure. The gripping axis is understood to be the circumferential axis around which, under gripping conditions, the aforementioned sensors are circumferentially distributed. The term radial and the expression radially inside / outside are used with reference to the radial direction of the gripping device and / or the annular structure of the tire, i.e., a direction perpendicular to the gripping axis of the gripping device and / or the tire axis of the annular structure of the tire. The term axial and the expression axially inside / outside are used with reference to the axial direction of the gripping device and / or the tire ring structure, i.e., a direction parallel to the gripping axis of the gripping device and / or the tire axis of the tire ring structure. The terms circumferentially and circumferentially are used with reference to the annular extension of the gripping apparatus and / or the annular structure of the tire. The term elastomeric material refers to a composition comprising at least one elastomeric polymer and at least one reinforcing filler. Preferably, this composition also includes additives such as, for example, a crosslinking agent and / or a plasticizer. Due to the presence of the crosslinking agent, the material can be crosslinked by heating to form the final manufactured product. CN104943212A describes a transfer ring comprising a right ring portion and a left ring portion that are relatively open and closed to each other. KR20110072180A describes a transfer device comprising a clamping unit coupled to a main body of the transfer device and a retaining portion that supports the outer circumferential surface of the green tire. A visible retaining portion is connected to the retaining portion by means of an intermediate connection. A cylinder is mounted between the variable retaining portion and the clamping unit. The applicant has noted that devices of the type described in CN104943212A do not allow adaptation to any size and / or geometric characteristic of the annular structures of the tires, for example dictated by the mounting diameter of the tire, since the two halves that constitute it have an average diameter of use. The applicant has also pointed out that, in the case of variations, sometimes even small, in the dimensions and / or geometric characteristics between production batches, devices such as those described in CN104943212A require the replacement of both half-parts and, therefore, the arrangement and management of multiple half-parts with different diameters. This increases plant layout and management costs, the space required, and the plant's curing time. These aspects are even more pronounced in the case of automated and highly diversified production of numerous small batches of tires characterized by dimensions and / or geometric characteristics that are quite different from one another. The applicant has further noted that, in cases of minor variations in the dimensions and / or geometric characteristics of the tire's annular structures, there is a tendency not to replace both half-pieces, as these are fixed at a mid-diameter, resulting in an unsatisfactory grip that can cause distortions or deformations of the tire's annular structure. Since the tire is not vulcanized, it is essentially in a plastic state and therefore potentially deformable. Such distortions or deformations can negatively affect the accuracy of the fit with other parts of the tire being processed and, consequently, the quality of the final product. Therefore, the applicant has identified the opportunity to simplify the production processes by automating the adjustment step of the parts that make up the gripping apparatus. From this perspective, the applicant has observed that also in an apparatus achieved as in KR20110072180A, there is an unsatisfactory gripping action due to the fact that the interaction zone between the tire and the retaining part or the variable retaining part changes depending on the relative position between these two parts. Therefore, the applicant has realized that by decoupling, at least partially, the actual contact zones (sensors) of a gripping device from the half parts (shoes) of the same that grip the annular structure of the tire, it is possible to obtain satisfactory solutions for flexibility of use and setup times during the construction of said tires. Finally, the applicant has found that it is possible to facilitate a more precise and stable coupling between a gripping device and an annular tire structure by arranging shoes associated with sensors and adjusting the relative position of the sensors of each shoe to arrange them along an adjustment circumference with a diameter equal to the diameter of a radially external surface of the annular tire structure. According to a first aspect, the invention relates to a method for gripping an annular structure of the tire. Preferably, in accordance with action a), an annular tire structure is provided which extends circumferentially around a tire axis and which has a radially outer surface having, in a plane perpendicular to said tire axis, a first gripping diameter. It is provided, preferably according to action b), for the arrangement of a gripping apparatus comprising at least two shoes, each shoe comprising at least two sensors distributed circumferentially around a gripping axis and each with a contact zone corresponding to a part of the sensor directed towards the gripping axis. Preferably, in accordance with action c), the relative position of the sensors of each shoe is provided to be adjusted so that, in a plane perpendicular to the grip axis, the contact zones of the sensors of one shoe are tangent to the same first adjustment circle having a diameter equal to said first adhesion diameter, said first adjustment circle being adapted to overlap the radially outer surface of the annular structure of the tire. Preferably, in accordance with action d), the gripping apparatus and the annular structure of the tire are positioned relatively such that the shoes are circumferentially around the annular structure of the tire. Preferably, in accordance with action e), the shoes are closed against the annular structure of the tire until the contact zones of the sensors grip the annular structure of the tire, being contiguous against the radially outer surface. According to a second aspect, the invention relates to a gripping device for gripping an annular structure of the tire having a radially outer surface. Preferably, a support structure is provided that carries at least two footings. Preferably, each shoe has at least two sensors circumferentially distributed around a gripping axis, each sensor having a contact zone corresponding to a portion of the sensor directed towards the gripping axis. Preferably, each shoe comprises an adjustment device configured to adjust the relative position of said at least two sensors such that in a plane perpendicular to the grip axis, the contact zones of the sensors of a shoe are tangent to the same first adjustment circle having a diameter equal to a first grip diameter of said annular structure of the tire, said first adjustment circle being adapted to overlap the radially outer surface of the annular structure of the tire. Preferably, a movement group is provided operationally between the support structure and the footings to close or open the footings to each other. The applicant believes that adjusting the relative position of the sensors on each shoe to grip the tire's annular structure allows the gripping device to be adapted to the specific geometric characteristics of the tire being processed, facilitating a more precise and stable coupling of the tire for movement and / or transfer without deformation. Since tire manufacturing requires the assembly of two or more annular structures or the construction of an annular structure within existing ones, improving their relative positioning leads to an improvement in the quality of the finished tire.Furthermore, the adjustment can be automated and is particularly advantageous for small production batches, as it is not necessary to intervene to replace the shoes when switching from one production batch to another, thus reducing setup times, the number of components that need to be kept in storage, the total cost of the plant, and logistical problems. In one or more of the aspects indicated, the present invention may comprise one or more of the following features. Preferably, the opening of the brake shoes and the release of the tire's annular structure are planned. Preferably, the relative position of the sensors of each shoe is maintained and actions d)-e) are repeated to grip another annular structure of the tire that has said first gripping diameter. Preferably, the arrangement of an annular tire structure is provided which has a radially outer surface with, in a plane perpendicular to the axis of the respective tire, a second grip diameter different from said grip diameter of the first. Preferably, the relative position of the sensors of each shoe is to be adjusted so that, in a plane perpendicular to the grip axis, the contact zones of one shoe are tangent to the same second adjustment circle having a diameter equal to said second grip diameter, said second adjustment circle being adapted to overlap the radially outer surface of the annular structure of the tire. Preferably, the repetition of actions d)-e) is foreseen to grip said annular structure of the tire with said second gripping diameter. The applicant believes that adjusting the sensors with each modification, even a limited one, of the geometric characteristics of the tire's annular structure improves grip, with positive repercussions on the quality of the finished tire. Preferably, action c) consists of moving at least one sensor of a shoe, while keeping at least one sensor of the same shoe stopped. Preferably, said adjustment device is operatively connected to at least one sensor of the respective shoe to move it with respect to at least one sensor of the same shoe. The applicant considers that the movement of at least one sensor with respect to the other sensors of a shoe allows simplifying the adjustment step, while keeping the contact point between the gripping device and the annular structure of the tire defined and secure. Preferably each shoe comprises at least three sensors and action c) consists of moving at least one sensor of a shoe, while keeping at least two sensors of the same shoe stationary. Preferably, each shoe comprises at least three sensors. Preferably, said adjustment device is operatively connected to at least one sensor of the respective shoe to move it with respect to at least two sensors of the same shoe. The applicant believes that keeping two fixed sensors simplifies the adjustment step without negatively affecting the relative accuracy of the positioning. Preferably, each shoe consists of four sensors and action c) comprises moving two sensors of a shoe with respect to the two remaining sensors of the same shoe. Preferably, each shoe consists of four sensors. Preferably, said adjustment device is operatively connected to two sensors of the respective shoe to move them with respect to the two remaining sensors of the same shoe. The applicant believes that the placement of four sensors, including two sensors that are movable relative to the rest, allows the shoes to be extended circumferentially, limiting the number of sensors even if a high fit and, therefore, a high gripping accuracy is achieved. Preferably, each shoe comprises a main portion and a lateral portion circumferentially adjacent to the main portion. Preferably, said main portion comprises at least one sensor and said side portion comprises at least one sensor. Even more preferably, said main portion comprises two sensors and said side portion comprises at least one sensor. Preferably, action c) involves moving said lateral portion with respect to the main portion. Preferably, said adjustment device is operatively interposed between said main portion and said side portion to move the side portion with respect to the main portion. The applicant believes that the division of the shoe allows the movement of the sensors, limiting the excessive structural complications of the gripping apparatus. Preferably, each shoe comprises a main portion, a lateral portion arranged circumferentially adjacent to a first side of the main portion, and a lateral portion arranged circumferentially adjacent to a second side of the main portion opposite said first side. Preferably, said main portion comprises at least one sensor and each side portion respectively comprises at least one sensor. Preferably, action c) involves moving each side portion with respect to the main portion. Preferably, said adjustment device is operatively interposed between said main portion and said side portions to move each side portion with respect to the main portion. Preferably, the main portion has two sensors and each side portion comprises one sensor respectively. The applicant believes that a symmetrical division of the footing facilitates the accuracy of the adjustment, simplifying its structure and operation. Preferably, the two lateral portions move with respect to the main portion through a synchronous and symmetrical movement. Preferably, said adjustment device comprises a motor member and a transmission system configured to move the two side parts with respect to the main part by means of a synchronous and symmetrical movement. The applicant believes that a synchronous and symmetrical movement facilitates positioning along the desired adjustment circumference. Preferably, each side portion is articulated to the respective main portion along a rotation axis parallel to the gripping axis. Preferably, moving the lateral portion comprises rotating the lateral portion around said axis of rotation. Preferably, said adjustment device is configured to rotate the lateral portion around said axis of rotation. Preferably, action e) comprises blocking said lateral portion 5 with respect to said main portion and radially moving said main portion with respect to a support structure of said gripping apparatus. Preferably, said movement group is operationally connected to said main portion to move it with respect to said support structure along a radial direction with respect to said gripping axis. The applicant believes that dividing the adjustment movement, 15 entrusted to the side parts, from the approach / remove movement, entrusted to the main part, allows for optimization of the components and their operation. Preferably, action e) consists of radially moving at least one shoe near the annular structure of the tire. Preferably, said movement group comprises an actuator for each shoe configured to move said shoe along a radial direction with respect to said gripping axis. Preferably, said gripping device comprises two diametrically opposed shoes. Preferably, action e) comprises moving the two shoes together relatively along the same radial direction with respect to said gripping axis. Preferably, said movement group is configured to move the two shoes relatively close to or far from each other along the same radial direction with respect to said gripping axis. The applicant considers that the provision of a gripping device of the type with two shoes provided with adjustable sensors combines the effectiveness of the adjustment and structural simplicity. Preferably, action e) consists of moving each shoe independently of the others. The applicant believes that by independently moving the shoes it is possible to adapt to the height variations between the pickup point and the release point of the tire's annular structure. Preferably, each shoe forms a cylindrical sector of the casing that extends axially along the gripping axis and is adapted to be arranged around an angular portion of an annular structure of the tire. Preferably, these sensors are obtained by means of inserts applied on a radially internal surface of said cylindrical sector of the housing. Preferably, each sensor is reached in such a way that it presents an extended contact zone along the gripping axis. Preferably, the extended contact area can be continuous along the gripping axis. Alternatively, the extended contact area can be discontinuous along the gripping axis. Preferably, the sensors of a shoe are distributed circumferentially in such a way that the two outermost circumferential sensors are arranged at an angular distance of less than 180°, in a range of grip diameters between 500 mm and 720 mm. Preferably, the sensors of a shoe are distributed circumferentially in such a way that the two outermost circumferential sensors are arranged at an angular distance greater than 90°, in a range of grip diameters between 500 mm and 720 mm. By providing at least three sensors on a shoe, preferably two successive circumferential sensors are arranged at an angular distance between 45° and 60°, in a range of grip diameters between 500 mm and 720 mm. Preferably, the annular structure of the tire is a casing sleeve. Preferably, the motor member is a rotary actuator. Alternatively, the motor member is a linear actuator. Preferably, the transmission system comprises a push arm for each side part. Preferably, the push arms are slidably mounted on the main part. Preferably, the drive member is operatively connected to the thrust arms to cause a synchronous and opposite translation of the same. Preferably, the transmission system comprises a motion reversing member operatively connected to the push arms and the motor member. Preferably, the reverse motion member is achieved by means of a pinion interposed between two frames, each associated with a push arm. Preferably, the drive member is connected directly to the pinion. Alternatively, the drive member is connected directly to one of the two push arms. Preferably each push arm has one end operatively associated with a side portion to move it relative to the main portion. Preferably, the push arms are articulated to allow rotation of the respective side portion around the axis of rotation. Even more preferably, at least one articulation of each push arm is achieved by means of a connecting rod configured to allow adjustment of a reference position between the main portion and the side portions. Preferably, the shoes are enclosed against a cylindrical body with an outer diameter equal to the diameter of the first handle, and the relative position of the main portion and the side portion is adjusted, preferably by means of the tie rod. Other features will become more apparent from the following detailed description. This description will be set out below with reference to the accompanying drawings, provided simply as a non-limiting example, in which: -The figure schematically shows a perspective view of a gripping device for gripping an annular tire structure; - Figure 2 shows a front view of the gripping device of Figure 1; - Figure 3 and Figure 4 illustrate the gripping apparatus of Figure 1 and Figure 2 respectively in a first operating condition; - Figure 5 and Figure 6 illustrate the gripping apparatus of Figure 1 and Figure 2 respectively in a second operating condition; - Figure 7 illustrates the gripping apparatus of Figure 2 in a third operating condition; - Figure 8 and Figure 9 illustrate the gripping apparatus of Figure 1 and Figure 2, respectively, in a fourth operating condition; - Figure 10 illustrates an enlarged detail of Figure 1. With reference to the attached figures, reference number 1 indicates a gripping device for gripping an annular tire structure 100. The annular structure of tire 100 extends circumferentially around an axis of tire P and has a radially outer surface 101. The radial outer surface 101 extends along the axis of tire P and has, in a plane perpendicular to the axis of tire P, a gripping diameter. Preferably, the tire structure 100 has a substantially cylindrical shape. The gripping device 1 is adapted to grip tire annular structures 100 with different grip diameters, for example, at least one tire annular structure with a first grip diameter DI and at least one tire annular structure with a second grip diameter D2 different from DI. Preferably, the gripping device is adapted to grip a tire annular structure with a grip diameter between 500 mm and 720 mm. The gripping apparatus 1 comprises a support structure 2 that carries at least two shoes 3. The gripping apparatus 1 also comprises a movement group 4 operatively interposed between the support structure 2 and the shoes 3 to close or open the shoes to each other. A plurality of sensors 5 (Figures 1-3 and 10) are carried by the shoes 3. When the shoes 3 - being closed - grip (as will be described below) said annular structure of the tire 100 by means of said sensors 5, these are distributed circumferentially around a gripping axis X that coincides with said axis of the tire P. The gripping axis X is preferably arranged in a horizontal plane. Each shoe 3 comprises at least two sensors 5 from the aforementioned plurality of sensors. According to one possible embodiment, each shoe comprises at least three sensors 5, preferably four sensors 5. Each sensor 5 has, in a plane perpendicular to the gripping axis X, a contact zone 6 (figures 1-3) corresponding to a part of the sensor directed towards the gripping axis X and intended to be supported against the radially outer surface 101 of the annular structure of the tire 100. Preferably, each sensor 5 is reached so that it has a contact zone 6 extending along the gripping axis X. The extended contact zone 6 can be continuous or discontinuous along the gripping axis X. Preferably, the sensors 5 of a shoe 3 are circumferentially distributed such that the two outermost circumferential sensors are arranged at an angular distance of less than 180°, in a range of grip diameters between 500 mm and 720 mm. Preferably, the sensors 5 of a shoe 3 are circumferentially distributed such that the two outermost circumferential sensors are arranged at an angular distance greater than 90°, in a range of grip diameters between 500 mm and 720 mm. By providing at least three sensors 5 on a shoe 3, preferably two successive circumferential sensors are arranged at an angular distance between 45° and 60°, in a range of grip diameters between 500 mm and 720 mm. Preferably, each shoe 3 forms a cylindrical sector of the casing, for example, a half-cylindrical casing, extending axially along the gripping axis X and adapted to be arranged around an angular portion of the tire's annular structure 100. Even more preferably, the sensors 5 are obtained by means of inserts applied to a radially internal surface 7 (Figures 1-3) of the cylindrical sector of the casing. For example, each sensor 5 comprises at least one strip 5a (Figures 1-3 and 10) arranged parallel to the gripping axis X. Each strip 5a can extend to cover the axial extent of the respective sector of the casing, or can cover a portion of the axial extent, possibly providing two or more strips 5b along the same direction parallel to the gripping axis X.According to the example illustrated in the figures, a sensor 5 comprises at least two strips 5b arranged along the same direction parallel to the gripping axis X to project externally from the respective cylindrical sector of the housing. Preferably, motion group 4 is configured to move each shoe 3 independently of the others, for example, by providing an actuator for each shoe 3. Preferably, motion group 4 is configured to move each shoe 3 along a radial direction with respect to the gripping axis X. Each shoe 3 comprises an adjustment device 8 configured to adjust the relative position of the sensors 5 of the respective shoe. Preferably, the adjustment device 8 is operatively connected to at least one sensor 5 of the respective shoe 3 to move it with respect to at least one other shoe 5 of the same shoe 3. In the event that each shoe comprises at least three sensors 5, the adjustment device 8 is operatively connected to at least one sensor 5 of the respective shoe 3 to move it with respect to at least two sensors 5 of the same shoe 3. In the case where each shoe comprises four sensors 5, the adjustment device 8 is operatively connected to two sensors of the respective shoe 3 to move them with respect to the two remaining sensors of the same shoe 3. According to one possible embodiment, each footing 3, preferably in the form of a cylindrical shell sector, comprises a main portion 9 and at least one lateral portion 10 arranged circumferentially adjacent to the main portion 9. Preferably, each footing 3 comprises a main portion 9, a lateral portion 10 arranged circumferentially adjacent to a first side of the main portion 9, and a lateral portion 10 arranged circumferentially adjacent to a second side of the main portion 9, opposite the first side. The movement group 4 is operatively connected to the main part 9 to move it relative to the support structure 2 along a radial direction with respect to the gripping axis X. The main portion 9 comprises at least one sensor 5, preferably two sensors 5. Each side portion 10 comprises at least one sensor 5, preferably one sensor 5. The adjustment device 8 is operatively interposed between the main portion 9 and the side portion / portions 10 to move the side portion / portions 10 with respect to the main portion 9. Preferably, the side portion / portions 10 are articulated to the main portion 9 along a rotation axis Y parallel to the gripping axis X. The adjustment device 8 is configured to rotate the side portion / portions 10 around the rotation axis Y (Figure 10). Preferably, the adjustment device 8 is configured to move the two side portions 10 with respect to the main part 9 by means of a synchronous and symmetrical movement. As illustrated, for example, in Figure 10, the adjustment device 8 comprises a single motor member 11, preferably mounted on the main part 9, and a transmission system 12 configured to move the two side parts 10 with respect to the main part 9 by means of a synchronous and symmetrical movement. Preferably, the motor member 11 is a rotary actuator. Alternatively, the motor member 11 is a linear actuator. Preferably, the transmission system 12 comprises a push arm 13 for each side portion 10. The push arms 13 are slidably mounted on the main part 9 and the drive member 11 is operatively connected to the push arms 13 to cause a synchronous and opposite translation of the same. Preferably, the transmission system 12 comprises a motion reversal member 14 operatively connected to the push arms 13 and the drive member 11. For example, the motion reversal member is achieved by means of a pinion 15 interposed between two frames 16, each associated with a push arm 13. If the drive member 11 is a rotary actuator, the latter can be connected directly to the pinion 15 or to one of the two push arms 13, for example, by means of a conversion device 17 configured to convert the rotary motion of the drive member 11 into linear motion of the push arm 13. The conversion device 17 is achieved, for example, by means of a screw-nut system. If the motor member 11 is a linear actuator, the latter can be directly connected to one of the two push arms 13. Each push arm 13 has one end operatively associated with a side portion 10 for movement relative to the main portion 9. Preferably, the push arms 13 are articulated to allow rotation of the respective side portion 10 around the rotation axis Y. Even more preferably, at least one articulation of each push arm 13 is achieved by means of a connecting rod configured to allow adjustment of a reference position between the main portion 9 and the side portions 10, and in such a way that the connecting rod allows adjustment of the side portions 10, making them symmetrical. The accompanying figures illustrate a preferred embodiment having two shoes 3 arranged in diametrically opposite positions. Preferably, each of the two shoes 3 forms a cylindrical half-housing adapted to be arranged around an angular portion of the tire's annular structure 100. Even more preferably, the gripping apparatus 1 comprises a lower shoe 3 and an upper shoe 3. According to this preferred embodiment, the movement group is preferably configured to move the two shoes 3 relatively close to or far from each other along the same radial direction with respect to the gripping axis X, preferably along a vertical direction. Preferably, each shoe 3 of the preferred embodiment comprises at least three sensors 5, preferably four sensors 5. Preferably, each shoe 3 of the preferred embodiment comprises the main portion 9, the side portion 10 arranged circumferentially adjacent to the first side of the main portion 9, and the side portion 10 arranged circumferentially adjacent to the second side of the main portion 9, opposite the first side. Preferably, the main portion 9 has two sensors 5, each side portion 10 respectively comprises at least one sensor 5 (preferably one sensor 5), and the adjustment device 8 is operatively interposed between the main portion 9 and the side portions 10 to move each side portion 10 relative to the main portion 9. The adjustment device 8 is preferably configured to move the two side portions 10 with respect to the main part 9 by means of a synchronous and symmetrical movement and comprises the motor member 11 and the transmission system 12 as described above. According to the preferred embodiment illustrated in the accompanying figures, the support structure 2 preferably has a guide 18, preferably vertical, and each of the two shoes 3 is slidably mounted on the guide 18, for example, by means of a slide 20. Preferably, the movement group 4 is configured to move each shoe 3 independently of the other, for example, by providing a drive member for each shoe 3. The use of the gripping device constitutes a method of gripping an annular structure of the tire, in which the arrangement of the annular structure of the tire 100 with the first gripping diameter DI (action a)) and of the gripping device 1 (action b)) are provided. Preferably, the annular structure of the tire 100 is a casing sleeve; therefore, the use of the gripping device implements a method for gripping a casing sleeve. According to action c), the relative position of the sensors 5 of each shoe 3 is adjusted such that, in a plane perpendicular to the grip axis X, the respective contact zones 6 are tangent to the same first adjustment circle 21 (Figure 4) having a diameter equal to the first grip diameter DI. The first adjustment circle 21 is adapted to overlap the radial outer surface 101 of the annular structure of the tire 100. For example, Figures 1 and 2 illustrate an operating condition in which the sensors 5 of a shoe 3 are tangent to the same circle 22, which has a smaller diameter than the diameter of the first grip DI. In Figure 4, the first adjustment circle 21 is drawn, with a diameter equal to the diameter of the first grip DI. The relative position of the sensors 5 of each shoe 3 is adjusted, moving from circle 22 to the first adjustment circle 21, as indicated by arrows F in Figure 4, before gripping the relative annular structure of the tire 100 (Figures 5 and 6). To adjust the relative position of the sensors 5 of each shoe 3, according to action c), it is provided to move at least one sensor 5 of a shoe, while keeping at least one sensor 5 of the same shoe 3 stationary. If each shoe 3 comprises at least three sensors 5, action c) comprises moving at least one sensor 5 of a shoe 3, while keeping at least two sensors 5 of the same shoe 3 stationary. If each shoe 3 comprises four sensors 5, action c) comprises moving two sensors 5 of a shoe 3 with respect to the remaining two sensors 5 of the same shoe 3. If each footing 3 comprises the main portion 9 and a side portion 10, action c) comprises moving the side portion 10 with respect to the main portion 9. If each footing 3 comprises the main portion 9 and two side portions 10, action c) comprises moving each side portion 10 with respect to the main portion 9. Preferably, the two side portions 10 are moved with respect to the main portion 9 by a synchronous and symmetrical movement. If each side portion 10 is articulated to the respective main portion 9 along the rotation axis Y, moving the side portion 10 comprises rotating the side portion 10 around the rotation axis Y. According to action d), the gripping apparatus 1 and the annular structure of the tire 100 are positioned relatively such that the shoes 3 are circumferentially around the annular structure of the tire 100. The annular structure of the tire 100 is transported, for example, on a radially outside surface of a building and / or transfer drum. In accordance with action (e), the shoes are intended to close against the annular structure of the tire 100 until the contact zones 6 of the sensors 5 grip the annular structure of the tire 100, being joined against the radially outer surface 101 (Figures 5-6). The construction and / or transfer drum, if present, contracts radially and moves away in such a way that the annular structure of the tire 100 is retained by the gripping apparatus 1. The annular structure of the 100 tire, thus gripped, is subjected to processing and / or transfers and then released by opening the 3 shoes with an opposite movement that is activated to close them. Preferably action e) consists of radially moving at least one shoe 3 near the annular structure of the tire 100. Preferably, at the end of the adjustment, the side portion / portions 10, if present, are locked with respect to the main portion 9 and to close a shoe 3 an arrangement is made to radially move the respective main portion 9 with respect to the support structure 2 to integrally drive the side portion / portions 10. To grip another annular structure of the 100 tire with the first gripping diameter DI, it is planned to maintain the relative position of the sensors 5 of each shoe 3 and repeat the actions of) . When an annular structure of the tire 100 is arranged with a second gripping diameter D2 different from the diameter of the first grip DI (Figure 7), the relative position of the sensors 5 of each shoe 3 is adjusted such that, in a plane perpendicular to the gripping axis X, the respective contact zones 6 are tangent to the same second adjustment circle 23, which has a diameter equal to the second gripping diameter D2. The relative position of the sensors 5 of each shoe 3 is adjusted, moving from the first adjustment circle 21 to the second adjustment circle 23 as indicated by the arrows F in Figure 7 before gripping the relative annular structure of the tire 100 (Figures 8 and 9). The second adjustment circle 23 is adapted to overlap the radially outer surface 101 of the annular structure of the tire 100. The actions d)-e) are then provided for repeating to grip said annular structure of the tire 100 having the second gripping diameter D2. According to the preferred embodiment illustrated, for example, in the accompanying figures, adjusting the relative position of the sensors 5 of each shoe 3 according to action c) actuates the motor member 11, causing the sliding of a push arm 13 and, consequently, of the respective rack 16. The presence of the pinion 15 forces the other push arm 13 to slide synchronously and in the opposite direction. A mutual movement of the push arms 13 generates a synchronous and symmetrical rotation of the lateral portions 10 near the gripping axis X (Figure 7). This movement is generated when the gripping diameter of the annular structure of the tire 10 to be gripped is smaller than the previously established gripping diameter. A mutual approach of the push arms 13 generates a synchronous and symmetrical rotation of the lateral portions 10 away from the gripping axis X (Figure 4).This movement is generated when the gripping diameter of the annular structure 15 of the tire to be gripped is greater than the previously established gripping diameter. Once the relative position of the sensors 5 of each shoe 3 is established, the lateral portions 10 are locked with respect to the main portion 9, for example by stopping the motor member 11 and maintaining their mutual positions. According to the preferred embodiment, for example, illustrated in the figures, the gripping axis X is horizontal, therefore the annular structure of the tire 100 is inserted into the shoes 3 with the tire axis P horizontal. In this case, action e) comprises moving the two shoes 3 together relatively along the same radial direction with respect to the gripping axis X, in particular along the vertical direction. At least one of the two shoes 3 moves 5 by radially translating the main portion 9 with respect to the support structure 2 to integrally drive the lateral portions 10. Depending on the gripping position of the tire axle P, the two shoes move simultaneously or independently of each other. Preferably, as a preliminary measure, it is planned to close the shoes against a cylindrical body with an outside diameter equal to the diameter of the first handle and adjust the relative position of the main portion and the side part, 15 preferably by means of the connecting rod of the push arms 13.

Claims

1. A method for gripping the annular structure of a tire (100) comprising: a) providing an annular structure of the tire (100) extending circumferentially around a tire axis (P) and having a radially outer surface (101) having, in a plane perpendicular to said tire axis (P), a first gripping diameter (DI); b) providing a gripping apparatus (1) comprising at least two shoes (3), each shoe (3) comprising at least two sensors (5) distributed circumferentially around a gripping axis (X) and each having a contact area (6) corresponding to a portion of the sensor (5) directed towards the gripping axis (X);c) adjusting the relative position of the sensors (5) of each shoe (3) such that, in a plane perpendicular to the gripping axis (X), the contact areas (6) of the sensors (5) of a shoe (3) are tangent to the same first adjustment circle (21) having a diameter equal to said first gripping diameter (DI), said first adjustment circle (21) being adapted to overlap the radially outer surface (101) of the tire annular structure (100); d) positioning said gripping apparatus (1) and said tire annular structure (100) relative to said shoes (3) such that said shoes (3) are circumferentially around said tire annular structure (100); e) closing the shoes (3) against the tire annular structure (100) until the contact areas (6) of the sensors (5) grip the tire annular structure (100) when joined against the radially outer surface (101).

2. Method according to claim 1, characterized in that it comprises opening the shoes (3) and releasing the annular structure of the tire (100).

3. Method according to claim 2, characterized in that it comprises maintaining the relative position of the sensors (5) of each shoe (3) and repeating actions d)-e) to grip another annular structure of the tire (100) having said first grip diameter (DI).

4. Method according to claim 2, characterized in that it comprises: arranging an annular tire structure (100) with a radially outer surface (101) having, in a plane perpendicular to the respective tire axis (P), a second grip diameter (D2) different from said first grip diameter (DI), adjusting the relative position of the sensors (5) of each shoe (3) such that, in a plane perpendicular to the grip axis (X), the contact zones (6) of a shoe (3) are tangent to the same second adjustment circle (23) having a diameter equal to said second grip diameter (D2), said second adjustment circle (23) being adapted to overlap the radially outer surface (101) of the annular tire structure (100), repeating actions d)-e) to grip said annular tire structure (100) having said second grip diameter (D2).

5. Method according to one or more of the preceding claims, characterized in that action c) comprises moving at least one sensor (5) of a shoe (3), while keeping at least one sensor (5) of the same shoe (3) stopped.

6. Method according to one or more of the preceding claims, characterized in that each shoe (3) comprises at least three sensors (5) and wherein action c) comprises moving at least one sensor (5) of a shoe (3), while keeping at least two sensors (5) of the same shoe (3) stationary.

7. Method according to one or more of the preceding claims, characterized in that each shoe (3) comprises four sensors (5) and wherein action c) comprises moving two sensors (5) of a shoe (3) with respect to the two remaining sensors (5) of the same shoe (3).

8. Method according to claim 5, characterized in that each shoe (3) comprises a main portion (9) and a side portion (10) circumferentially adjacent to the main portion (9), said main portion (9) comprises at least one sensor (5) and said side portion (10) comprises at least one sensor (5), and characterized in that action c) comprises moving said side portion (10) with respect to the main portion (9).

9. Method according to claim 6, characterized in that each shoe (3) comprises a main portion (9) and a side portion (10) circumferentially adjacent to the main portion (9), said main portion (9) comprises two sensors (5) and said side portion (10) comprises at least one sensor (5), and wherein action c) comprises moving said side portion (10) with respect to the main portion (9).

10. Method according to one or more of the preceding claims, characterized in that each shoe (3) comprises a main portion (9), a side portion (10) arranged circumferentially adjacent to a first side of the main portion (9) and a side portion (10) arranged circumferentially adjacent to a second side of the main portion (9) opposite said first side, said main portion (9) comprising at least one sensor (5) and each side portion (10) respectively comprising at least one sensor (5), and wherein action c) comprises moving each side portion (10) with respect to the main portion (9).

11. Method according to claim 10 when dependent on claim 7, characterized in that said main portion (9) has two sensors (5) and each side portion (10) respectively comprises one sensor (5).

12. Method according to claim 10 or 11, characterized in that the two lateral portions (10) move with respect to the main portion (9) by means of a synchronous and symmetrical movement.

13. Method according to one or more of claims 8 to 12, characterized in that each side portion (10) is articulated to the respective main portion (9) along a rotation axis (Y) parallel to the gripping axis (X) and wherein moving the side portion (10) comprises rotating the side portion (10) about said rotation axis (Y).

14. Method according to one or more of claims 8 to 13, characterized in that action e) comprises locking said lateral portion (10) with respect to said main portion (9) and radial movement of said main portion (9) with respect to a support structure (2) of said gripping apparatus (1).

15. Method according to one or more of the preceding claims, characterized in that action e) consists of radially moving at least one shoe (3) near the annular structure of the tire (100).

16. Method according to one or more of the preceding claims, characterized in that said gripping apparatus (1) comprises two diametrically opposed shoes (3) and wherein action e) comprises moving the two shoes (3) together relatively along the same radial direction with respect to said gripping axis (X).

17. Method according to claim 15 or 16, characterized in that action e) comprises moving each shoe (3) independently of the others.

18. Gripping apparatus for gripping an annular tire structure (100) with a radially outer surface (101), comprising: a support structure (2) carrying at least two shoes (3); each shoe (3) having at least two sensors (5) circumferentially distributed around a gripping axis (X), wherein each sensor (5) has a contact zone (6) corresponding to a portion of the sensor (5) directed towards the gripping axis (X);wherein each shoe (3) comprises an adjustment device (8) configured to adjust the relative position of said at least two sensors (5) such that in a plane perpendicular to the gripping axis (X), the contact zones (6) of the sensors (5) of a shoe (3) are tangent to the same first adjustment circle (21) having a diameter equal to a first grip diameter (DI) of said annular structure of the tire (100), said first adjustment circle (21) being adapted to overlap the radially outer surface (101) of the annular structure of the tire (100); A movement group (4) operatively interposed between the support structure (2) and the shoes (3) for closing or opening the shoes (3) with each other.

19. Gripper according to claim 18, characterized in that said adjustment device (8) is operatively connected to at least one sensor (5) of the respective shoe (3) to move it with respect to at least one sensor (5) of the same shoe (3).

20. Gripper apparatus according to claim 18 or 19, characterized in that each shoe (3) comprises at least three sensors (5) and characterized in that said adjustment device (8) is operatively connected to at least one sensor (5) of the respective shoe (3) to move it with respect to at least two sensors (5) of the same shoe (3).

21. Gripper apparatus according to one or more of claims 18 to 20, characterized in that each shoe (3) comprises four sensors (5) and wherein said adjustment device (8) is operatively connected to two sensors (5) of the respective shoe (3) to move them with respect to the two remaining sensors (5) of the same shoe (3).

22. Gripper according to claim 19, characterized in that each shoe (3) comprises a main portion (9) and a side portion (10) arranged circumferentially adjacent to the main portion (9), said main portion (9) comprising at least one sensor (5) and said side portion (10) comprising at least one sensor (5), and wherein said adjustment device (8) is operatively interposed between said main portion (9) and said side portion (10) in order to move the side portion (10) with respect to the main portion (9).

23. Gripper according to claim 20, characterized in that each shoe (3) comprises a main portion (9) and a side portion (10) arranged circumferentially adjacent to the main portion (9), said main portion (9) comprising two sensors (5) and said side portion (10) comprising at least one sensor (5), and wherein said adjustment device (8) is operatively interposed between said main portion (9) and said side portion (10) to move the side portion (10) with respect to the main portion (9).

24. A gripping apparatus according to one or more of claims 18 to 23, characterized in that each shoe (3) comprises a main portion (9), a side portion (10) arranged circumferentially adjacent to a first side of the main portion (9), and a side portion (10) arranged circumferentially adjacent to a second side of the main portion (9) opposite said first side, said main portion (9) comprising at least one sensor (5) and each side portion (10) respectively comprising at least one sensor (5), and wherein said adjustment device (8) is operatively interposed between said main portion (9) and said side portions (10) to move each side portion (10) with respect to the main portion (9).

25. Gripper according to claim 24, characterized in that said adjustment device (8) comprises a motor member (11) and a transmission system (12) configured to move the two side portions (10) with respect to the main part (9) by means of a synchronous and symmetrical movement.

26. Gripper according to one or more of claims 22 to 25, characterized in that each side portion (10) is articulated to the main portion (9) along a rotation axis (Y) parallel to the gripping axis (X) and wherein said adjustment device (8) is configured to rotate the side portion (10) about said rotation axis (Y).

27. Gripper according to one or more of claims 22 to 26, characterized in that said movement group (4) is operatively connected to said main portion (9) to move it with respect to said support structure (2) along a radial direction with respect to said gripper axis (X).

28. Gripper according to one or more of claims 22 to 27, characterized in that said movement group (4) comprises an actuator for each shoe (3) configured to move said shoe (3) along a radial direction with respect to said gripper axis (X).

29. Gripper according to one or more of claims 22 to 28, characterized in that it comprises two diametrically opposed shoes (3) and wherein said movement group (4) is configured to move the two shoes (3) relatively close to or far from each other along the same radial direction with respect to said gripper axis (X).

30. Gripping apparatus according to one or more of claims 10, 22 to 29, characterized in that each shoe (3) forms a cylindrical sector of the housing extending axially along the gripping axis (X) and adapted to be arranged around an angular portion of an annular structure of the tire (100), and wherein said sensors (5) are obtained by means of inserts applied on a radially internal surface (7) of said cylindrical sector of the housing.

Images