RU2588247C2 - Tyre assembly method and device for vehicle wheels - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: invention relates to method and device for assembling tyres of vehicle wheels. According to method rubber-coated ribbon, provided with a plurality of parallel reinforcing cords, is moved forward by a conveyor along a feeding direction (A) coincident with longitudinal extension direction (X), until exceeding a cutting region of conveyor by a predetermined length (L). Locating element, placed under rubber-coated ribbon and at cutting region, is lifted until lifting of rubber-coated ribbon occurs. Knife, placed upon rubber-coated ribbon and at cutting region, carries out incision of rubber-coated ribbon and cuts it between adjacent reinforcing cords and over whole width thereof so as to form a segment that is subsequently laid down on forming drum. Before cut, a first portion of rubber- coated ribbon placed upstream of locating element is moved forward by a predetermined stretch (d) for reducing tension of rubber-coated ribbon caused by lifting of locating element.

EFFECT: higher quality of finished articles.

32 cl, 11 dwg

Description

FIELD OF TECHNOLOGY

The present invention relates to a method and apparatus for assembling tires for vehicle wheels.

In particular, within the scope of the method and device, the present invention relates to cutting a rubber band for assembling tires for vehicle wheels. Such a cut rubberized tape is preferably used to make belt tapes in a tire for vehicle wheels.

BACKGROUND

A tire for vehicle wheels typically comprises a carcass structure comprising at least one carcass ply having end bent parts in contact with respective annular retaining structural members, each of which is usually formed with at least one a substantially circular annular insert on which at least one filler insert is applied, tapering radially from the axis of rotation. A belt structure located radially outwardly with respect to it is connected to the carcass structure, comprising one or more layers of the belt arranged to be superposed on one another and on the carcass layer in the radial direction and made with textile or metal reinforcing cords having orientation with crossing and / or essentially parallel to the circumferential direction of the tire. The tread band is radially superimposed externally on the belt structural member, and the tread band is also made of elastomeric material like other semi-finished products forming the tire. The so-called "lower layer" of the elastomeric material can be located between the tread band and the belt structural element, while the lower layer has properties that provide the possibility of durable connection of the belt structural element with the tread band. In addition, the respective sidewalls of elastomeric material are superimposed on the side surfaces of the frame structural element, with each of the sidewalls extending from one of the side edges of the tread band to the area adjacent to the corresponding annular retaining structural element in the sides. In "tubeless" type tires, the carcass ply is completely covered with a layer of elastomeric material, preferably based on butyl, commonly called the "sealing layer", which has optimal characteristics from the point of view of air tightness and extends from one side to the other.

It should be noted that for the purposes of the present description and the following claims, the term "elastomeric material" is understood to mean a composition containing at least one elastomeric polymer and at least one active filler. This composition further comprises additives, for example, such as a crosslinking agent and / or plasticizer. Due to the presence of a crosslinking agent, this material can be crosslinked to form the final industrial product.

It should also be noted that for the purposes of the present description and the following claims, the term "rubberized tape" is understood to mean a ribbon-like element formed with a plurality of textile or metal reinforcing cords substantially parallel to each other, coated with an elastomeric material or embedded in an elastomeric material and located with a slope at an angle other than zero, relative to the longitudinal direction of passage of the rubberized tape itself.

WO 03/035379 discloses a method and apparatus for cutting a strip of fabric coated with an elastomeric material and containing a plurality of reinforcing cords, used in particular for assembling reinforcing semi-finished products, such as reinforcing belt, configured to form a belt structural element, for not vulcanized tires. The method includes the following steps: forming an incision having a predetermined length and extending between two adjacent cords along the cutting direction by means of a center punch interacting with a counter-knife; introducing at least one cutting knife through an incision; making the first and second cuts of the strip by moving the knife along the cutting direction in the first section passing between the notch and the first lateral edge of the strip, and in the second section passing between the notch and the second lateral edge of the strip.

WO 2008/105655 discloses an apparatus for cutting an elastomeric component for manufacturing a tire breaker. The device comprises a roller conveyor including a plurality of parallel rollers located at a certain distance from each other and providing movement of the elastomeric component along the direction of movement. The cutting device comprises a knife for cutting the component at a certain cutting angle with respect to the direction of movement. The knife is made with the possibility of displacement on the guide relative to the conveyor and forms a certain angle relative to the direction of movement, which can be adjusted within the range of values, comprising from 18 to 34 °. A cutting device is provided with a lifting beam extending transverse to the direction of movement between the two drive rollers. The traverse is made with the possibility of movement in the vertical direction for lifting the elastomeric component during cutting.

SUMMARY OF THE INVENTION

In this area, the applicant has realized the need to improve the quality of segments of a given length obtained by cutting a rubberized tape, with particular mention should be made to the processing of the edges formed by cutting to improve the overall quality of tires made with these segments.

It has been found that an inaccurate incision that is not perfectly parallel to the reinforcing cords can lead to damage to the cords themselves, causing the ends of these cords to open or tear of said cords and / or the formation of segments in which one or more cords exit the elastomeric matrix.

In addition, the surface of the edges formed during cutting may be uneven at the end of the treatment, because if the rubberized tape is too tight during the cutting operation, it tends to stretch and tear in the area affected by the knife.

These defects affect the quality of the finished tire and the functionality of the machines that handle the cut segments for the manufacture of non-vulcanized tires to be vulcanized.

It has been found that the aforementioned disadvantages can be eliminated by a method and apparatus for assembling tires for vehicle wheels, in which cutting the rubberized tape provides a clear and precise separation of two consecutive segments along a cutting line located between two adjacent reinforcing cords.

Thus, it was found that if during cutting the area of the rubberized tape that is near the cutting line is not sufficiently stretched in the feed direction of the specified tape, which coincides with the longitudinal direction of the rubberized tape, this result can be achieved.

In particular, in accordance with a first aspect, the present invention relates to a method for assembling tires for vehicle wheels, comprising: forming at least one tire component on a forming drum, wherein the component is formed by:

- feeding the rubberized tape to the conveyor along the feed direction, which coincides with the longitudinal direction of passage of the specified rubberized tape, until it extends beyond the cutting zone provided for in the specified conveyor to a predetermined length; wherein the rubberized tape contains many parallel reinforcing cords embedded in a matrix of elastomeric material and having a slope at a given angle relative to the longitudinal direction of passage;

- lifting the installation element located under the rubberized tape and in the cutting zone, until then, until the rubberized tape is lifted;

- moving the knife located above the rubberized tape and in the cutting zone, along the cutting direction for cutting and cutting the rubberized tape between two adjacent reinforcing cords and across its entire width to form a cut;

- imposing a segment on the forming drum;

in this case, before cutting, the first part of the rubber tape, located in front of the installation element along the move, is moved forward by a predetermined length to reduce the tension of the specified rubber tape, resulting from the lifting of the installation element.

In accordance with a second aspect, the present invention relates to an apparatus for assembling tires for vehicle wheels, comprising:

- forming drum;

- a conveyor forming a supporting surface for the rubberized tape and having a first part and a second part arranged in series along the feed direction;

- a mounting element located between the first part and the second part, extending along a direction transverse to the feeding direction, and configured to move in a vertical direction between the lowered position in which it is under the supporting surface and the raised position in which it stands for the specified bearing surface;

- a knife mounted above the conveyor near the installation element and configured to move along a path passing at an angle relative to the feed direction;

wherein the forming drum is operatively connected to the conveyor for receiving a piece of rubberized tape cut by a knife;

moreover, the first part of the conveyor is configured to bring it into action independently of the second part;

wherein the mounting element comprises a support and at least one roller mounted on the support.

It is assumed that the movement of the part of the rubberized tape that is located upstream of the mounting element, towards the part located further downstream, and closer to the part located further downstream, facilitates the vertical displacement of the specified mounting element and that zone of the rubberized tape, which is in contact with it, to such an extent that it does not stretch the rubberized tape, local changes in the characteristics of the tape or even tearing the tape when the knife passes through it to cut it.

The present invention in accordance with at least one of the above aspects may have one or more preferred features described hereinafter.

In accordance with a preferred embodiment of the method, while moving the first part forward, the second part of the rubber band located downstream of the mounting member is stationary.

The second part, located downstream, is already correctly positioned to cut a segment with a length corresponding to the length of the tire component to be superimposed on the forming drum.

Moving the first part forward preferably includes: driving the first part of the conveyor located downstream of the installation element, regardless of the second part of the specified conveyor located along the specified installation element.

Therefore, providing this forward movement is relatively simple.

The predetermined length is preferably substantially equal to the elongation of the rubberized tape resulting from the lifting of the mounting element.

Displacement in the vertical direction and a predetermined displacement in the horizontal direction lead to the formation of a bulge in the rubberized tape with a shape and tension that are sufficient for the knife to incise and cut the tape without stretching it.

The predetermined length is preferably from about 10 mm to about 100 mm.

During this forward movement, the rubberized tape is preferably rolled forward on at least one support roller belonging to the mounting member.

Owing to the presence of the roller, a dangerous situation is avoided in which the mounting element drags the rubber tape along precisely during this stage of local forward movement, since the specified area of the rubber tape in contact with the roller and the roller itself “roll” along each other without significant slipping of each other relative to a friend.

According to a preferred embodiment of the method, during movement along the cutting direction, the knife passes between two support rollers belonging to the mounting member.

Thus, the knife does not collide with the mounting element and can freely pass through the rubberized tape precisely in the raised area.

After cutting, a piece of rubberized tape is preferably moved from the cutting zone.

During movement from the cutting zone, the end just formed during cutting is preferably rolled over one of these two support rollers.

The cut ribbon will be divided into two segments, one located closer along and one located further along. Each of the two complementary ends formed by cutting is tapering and lies only on one of the two supporting rollers. Therefore, the segment located further downstream can be removed from the cutting zone without relative slippage, since its end formed during cutting rolls along the corresponding roller, while the segment located closer along the course will be stationary, and its end, formed by cutting, lies motionless on the corresponding roller.

The rubber band is preferably laterally biased to center it relative to the forming drum, which is located further downstream.

This rationally helps to ensure the correct position of the cut segment on the forming drum.

In accordance with a preferred embodiment of the method, applying a cut to the forming drum comprises:

- winding a segment around the surface of the forming drum, outer in the radial direction; and

- connection with each other of the opposite ends of the specified segment.

The segment performs only one revolution around the forming drum and will ultimately be tubular.

The rubber band is preferably unwound from a bobbin. The rubberized tape, previously created and wound on a bobbin, after possible connection with an auxiliary fabric capable of preventing the coils of the tape from sticking to each other, is stored in such a way until it becomes necessary to use it in the method in accordance with the invention.

The tire component is preferably a belt tape.

The specified predetermined angle is preferably in the range from about 15 ° to about 35 °.

Preferably, if the cutting direction is parallel to the reinforcing cords. Reinforcing cords are preferably metal cords.

The method makes it possible to manufacture a belt structural member that preferably has metal cords that are preferably angled. If several overlay belts are to be provided, the belts of the belts will preferably intersect with the belts of another belts.

According to a preferred embodiment of the device, said at least one roller is a support roller. The roller rolls along the rubberized tape, since it is driven into rotation by moving the rubberized tape itself.

Said at least one roller preferably extends over the entire width of the conveyor. Therefore, the roller can provide support for rubberized tapes of different widths without skewing.

The mounting element preferably contains two rollers, the axis of rotation of which are essentially sequentially aligned along the specified transverse direction.

Each of the two rollers after cutting “receives” the end of only one of the two segments of the rubberized tape resting on them, and, therefore, can move in accordance with its movement regardless of the movement of the other end.

Each of the two rollers is preferably mounted to rotate freely on a support independently of the other.

Immediately after cutting, each roller will roll along the rubberized tape independently of the other roller when it is brought into rotation by moving the corresponding segment.

The two rollers preferably limit the passage between them for the knife. This passage is obtained due to the simple and functional design of the installation element.

According to a preferred embodiment, each of the two parts comprises a conveyor belt. The rubber band constantly rests on each of the two parts of the conveyor belt, which prevents its deformation when sagging down due to its own weight.

Each of the two parts preferably has a continuous abutment surface along which the conveyor belt moves. Consequently, conveyor belts can provide support for a rubber band without deformation.

The continuous abutment surface preferably comprises magnets. In the case of a rubberized tape with metal cords, magnets steadily hold said rubberized tape before cutting and after cutting.

The magnets are preferably embedded in a continuous abutment surface. Consequently, continuous bearing surfaces provide a smooth and continuous bearing surface for conveyor belts and rubberized belts.

The angled path of the knife and the feed direction preferably limit the angle of inclination of from about 15 ° to about 35 °.

The angle of inclination of the path is preferably adjustable.

The knife can cut many different rubberized tapes made with cords having a slope at different angles.

The knife preferably has two opposing recesses located along a path passing at an angle, and made with cutting edges.

The knife can cut the rubberized tape, moving in two directions along the cutting path, passing at an angle. The knife preferably passes through the rubber band at a point on the midline of the rubber band located at the passage bounded by two rollers, moves forward by cutting to the edge of the rubber band until it comes out of contact with the rubber band, then moves back until it comes into contact with the rubberized tape again at the same point in the midline, and continues to move backward, cutting, to the opposite edge.

The device preferably comprises a centering device configured to bias the conveyor laterally to center the rubberized tape relative to the forming drum, which is located further downstream.

The centering device preferably comprises:

- a sensor located between the second conveyor belt and the third conveyor belt and configured to determine the position of the rubber tape in the lateral direction; and

- acting device, functionally connected to the sensor and affecting the conveyor.

Preferably, the device comprises a reel located upstream of the conveyor and carrying a rubber band wound thereon.

The device preferably comprises a pre-centering device located between the reel and the conveyor and serving as a support for the rubber band; while the specified device for pre-centering is made with the possibility of displacement it in the lateral direction to adjust the position of the specified rubber tape relative to the conveyor.

The centering device and the pre-centering device make it possible to hold the tape in a proper position along the entire path of its movement from the bobbin to its placement on the forming drum, so that the cutting operation and the overlay operation can be performed with very high accuracy.

Additional features and advantages will become more apparent from the detailed description of a preferred, but not exclusive embodiment of a method and apparatus for assembling tires for vehicle wheels in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

This description will be presented hereinafter with reference to the accompanying drawings, given by way of non-limiting example, in which:

Figure 1 is a schematic vertical side view of a device in accordance with the invention;

Figure 2 is an enlarged perspective view of part of the device of figure 1;

Figa is a local side view of the device of Fig.1;

Fig.3b-3e - depicted in Fig.2 part in a vertical side view and in the form of a sequence of configurations during operation;

Figa and 4b - part of figure 2 in top views and in various configurations during operation;

5 is a half radial section of a tire assembled by using the device in accordance with the invention; and

Fig. 5a shows the tire element of Fig. 5 in cross section along a radial plane.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

1, a device for assembling tires for vehicle wheels and made in accordance with the present invention is generally designated 1.

A tire 2 made in an apparatus comprising said device and in accordance with the method of the present invention is shown in FIG. 5, and it essentially comprises a carcass structure 3 having at least one carcass ply 4. An airtight layer of elastomeric material or the so-called “sealing layer” 5 can be applied to the inner side of the carcass ply / s 4. Two annular retaining structural elements 6, each of which contains a so-called bead core 6a, bearing an elastomeric filler 6b placed radially from the outside, are in contact with the corresponding end bent parts 4a of the carcass ply 4a. The annular retaining structural elements 6 are embedded in the vicinity of zones, commonly referred to as “beads” 7, in which contact interaction usually takes place between the tire 2 and the corresponding mounting rim. The belt structural element 8, comprising several belt layers 8a, 8b, is laid in a circumferential direction around the carcass layer / s 4, and the tread band 9 overlaps the belt structure 8.

As shown in FIG. 5 a, each belt layer 8 a, 8 b contains a plurality of textile or metal reinforcing cords 10 parallel to each other, embedded in a matrix of elastomeric material 11 and positioned at a predetermined angle “α” relative to the direction “YY” of the tire 2 along circles. The reinforcing cords 10 of two adjacent breaker layers 8a, 8b are preferably crossed with each other.

The so-called "sub-belt insert" 12 can be connected to the belt structural element 8; each of them is placed between the layer / layers 4 of the frame and one of the axially opposite end edges of the belt structural element 8. Two sidewalls 13, each of which extends from the corresponding bead 7 to the corresponding lateral edge of the tread band 9, are laterally opposed places on layer / layers 4 of the frame.

These components of the tire 2 are made on one or more assembly drums, wherein said assembly drums are displaced between different workstations, on each of which respective devices provide the imposition of various semi-finished products on the assembly drum (s) / drums.

In a preferred embodiment, the installation comprises a frame assembly line on which one or more assembly drums are successively moved between different workstations for forming a frame sleeve / tube-like component on each assembly drum comprising a frame layer / layers 4, a sealing layer 5, annular holding structural elements 6 and, possibly, at least part of the sidewalls 13.

At the same time, on the assembly line of the outer sleeve component, one or more forming drums 14 are sequentially moved between different workstations designed to form, on each forming drum 14, an outer sleeve component comprising at least a belt structural element 8, a tread band 9 and, possibly at least part of the sidewalls 13.

The installation further comprises an assembly station at which the outer sleeve component is removed from the auxiliary drum for connecting the outer sleeve component to the frame sleeve component.

The assembled tires 2 are successively moved to at least one vulcanization device not shown.

The device 1 shown in FIG. 1 is intended for cutting a segment with a predetermined size from the rubberized tape 15 and for winding it around the surface 14a of the forming drum 14, external in the radial direction, to form one of these belt layers 8a, 8b.

Therefore, the rubberized tape 15 contains many of these parallel reinforcing cords 10, embedded in a matrix of elastomeric material 11 and located at a given angle “α” relative to the longitudinal direction “X” of the passage of the rubberized tape 15 itself (FIGS. 2, 4a and 4b), which in the finished tire corresponds to the indicated direction “YY”.

The device 1, illustrated in figure 1, contains a reel 16, on which the rubberized tape 15 is wound and on which it is stored, and a cutting device 17, located along the reel 16 and before the forming drum 14 relative to the direction “A” of the feed tape 15 ( which coincides with the indicated longitudinal direction “X” of passage).

The cutting device 17 comprises a conveyor 18, consisting of a first part 19 and a second part 20, including a first conveyor belt and a second conveyor belt, respectively, which are arranged sequentially one after the other along the indicated feed direction “A”. Each of the two conveyor belts 19, 20 is wound around pulleys 21, driven by preferably “brushless” / brushless motors, and has an upper bearing surface 22, which, resting on a continuous bearing surface 23, moves in the feed direction “A”. The conveyor 18 can provide support for the rubberized belts 15 with a width of up to about 350 mm, preferably up to about 400 mm, and allow for the movement of these belts.

The first and second conveyor belts 19, 20 define a gap 24 between them, which extends over the entire width of the conveyor 18 and in which the rubberized belt 15 does not rest on the upper supporting surfaces 22. The slot 24 extends along a direction orthogonal to the feed direction “A”.

Near the slit 24 is a mounting element 25, which can be offset along the vertical direction between the first position and the second position. The mounting element 25 includes a support 26, on which two rollers 27 are mounted with the possibility of free rotation independently of each other. Two rollers 27 are aligned along the slit 24 and have a common axis of rotation “Z-Z” (FIG. 2). The drive device 25a is arranged to move the support 26 together with the two rollers 27 between the first position and the second position.

In the first position, or in the lowered position (Figs. 1 and 3a), two rollers 27 are retracted into the slit 23, or, in other words, the upper end surface of the two rollers 27 is located under an imaginary supporting surface formed by lengthening the upper supporting surface 22 of the conveyor belts 19, 20.

In the second position, or in the raised position (FIGS. 3b-3e), two rollers 27 protrude upward from the slit 24 or, in other words, protrude beyond an imaginary abutment surface formed by lengthening the upper abutment surface 22 of the conveyor belts 19, 20.

The end ends 27a of the two rollers 27 facing each other define a passage 28 forming a “gap” zone of the surface of the two rollers 27, which is peripheral in the radial direction (FIGS. 2, 4a and 4b).

Above the conveyor 18, a beam-shaped straight guide 29 is provided for the knife 30. The guide 29 extends along a straight cutting direction “T” corresponding to the line along which the rubberized tape 15 is to be cut (FIGS. 2 and 4a). Therefore, the guide 29 is located at an angle relative to the longitudinal direction “X” of the passage of the rubber tape 15 (and relative to the direction “A” of the feed), while this angle is equal to the specified angle of inclination of the reinforcing cords 10. More precisely, the cutting direction “T” passes through the midline of the rubberized belt 15 and the conveyor 18 in the aforementioned passage 28 between the rollers 27, as can clearly be seen in plan view of FIG. Continuous adjustment of the angle of deviation of the beam for cutting strips with cords 10 having an angle of inclination from about 15 ° to about 35 °, preferably from about 20 ° to about 30 °.

The knife 30, preferably a knife with heated blades, extends downward and towards the conveyor 18 from the guide 29 and can translate along the guide 29 along the cutting direction “T” and in both directions, while it is driven by a motor not shown. The knife 30 has a “butterfly-shaped” symmetrical shape with two cutting edges extending from opposite sides of the central body 32 of the knife 30 itself, which coincide with the cutting directions. Each cutting edge has a notch apex 31a and a recess 31b formed at the top with respect to the notch apex 31a (FIGS. 2 and 3a).

Magnets 33 are inserted into the continuous supporting surface 23 of each of the conveyor belts 19, 20 flush with the sliding surface of the corresponding conveyor belt 19, 20 (Figs. 3a-3e), the function of which is to hold the rubberized belt 15 when the latter contains metal cords.

As shown in figure 1, the auxiliary conveyor 34 is located along the second conveyor belt 20, and it is formed by a third conveyor belt 35 wound on the pulleys 21 with a motor drive. The upper conveying surface 36, which is the surface of the third conveyor belt 35, is inclined downward, starting from the second conveyor belt 20. The shaping drum 14 is located above the distal portion of the third conveyor belt 35, and its radially outer surface 14a faces the upper surface 36 transportation and is located close to the upper transportation surface 36. The auxiliary conveyor 34 is also preferably provided with magnets not shown, the function of which is to hold the rubberized tape 15 made with metal cords 10.

The sensor 37 is located between the second conveyor belt 20 and the third conveyor belt 35, while the specified sensor is configured to determine the position of the rubberized tape 15 in the lateral direction, that is, in the direction transverse to the direction “A” of the feed, by means of an identification system of the edges of the rubberized tape itself 15. The sensor 37 is functionally connected to the actuating device 37a, shown only schematically in FIGS. 1 and 4a, acting on the conveyor 18 and configured to bias the conveyor 18 in a lateral direction and based on the processing of the signal received from the sensor 37, so that the middle line of the rubberized tape 15 corresponds to the middle line of the forming drum 14, on which it will be superimposed. Therefore, the sensor 37 and the actuating device 37a are part of the leveling device.

In the shown preferred embodiment, between the bobbin 16 and the first conveyor belt 19, a pre-centering device 38 is also located, comprising a frame 39 made with support elements not shown, on which the rubberized tape 15 coming from the bobbin 16 slides and with candle-shaped rollers 40 mounted with the possibility of free rotation idle on the frame 39 around the axes perpendicular to the rubberized tape 15, and located on both sides of it. The frame 39 can be offset laterally, that is, in a direction transverse to the feed direction “A”, for adjusting the position of the rubber band 15 relative to the conveyor 18.

When using and in accordance with the method according to the invention, the rubber band 15 made with metal reinforcing cords 10 is unwound from the bobbin 16, and it first rests on the pre-centering device 38 and then on the upper supporting surface 22 of the first conveyor belt 19, being held by magnets 33. The mounting element 25 is in the first lowered position. The first and second conveyor belts 19, 20 are driven synchronously so that they move at the same speed and ensure that the rubberized belt 15 moves forward until one end of it is near the third conveyor belt 35. At this point, the work performed by the leveling device centering the rubberized belt 15 relative to the third conveyor belt 35 and the forming drum 14, located further downstream.

After that, the first, second and third conveyor belts 19, 20, 35 are driven together so that they move at the same speed and ensure that the rubberized belt 15 moves forward behind the slit 24 by a predetermined length “L”, essentially corresponding to the circumference of the forming drum 14. At the end of this forward movement, a part of the rubber band 15 having a length “L” will be located partially on the second conveyor belt 20 and partially on the third conveyor belt 35 (FIGS. 1 and 3a).

When the conveyor belts 19, 20, 35 are stationary, the mounting element 25 is raised to the second position (Fig. 3b). The rollers 27 are moved and abut against the lower surface of the rubberized tape 15, and push it up. Immediately before this movement in the vertical direction, during or immediately after this movement in the vertical direction, the first conveyor belt 19 is driven independently to ensure that the first part of the rubber belt 15, which is located along the installation element 25, forward by a predetermined length “D” while the second conveyor belt 20 is held stationary (FIG. 3c). This forward movement causes the formation of a bulge, which contributes to the displacement of the mounting element 25 in the vertical direction and to prevent the formation of tensile stresses in the rubberized tape 15. The specified predetermined length “d” is essentially equal to the elongation of the rubberized tape 15 resulting from the displacement of the mounting element 25 in the vertical direction .

At this point, the knife 30, still located at the peripheral zone of the guide 29, is shifted along the cutting direction “T” to the first side until the tip 31a of one of the cutting edges makes an incision on the rubberized tape 15 on the bulge and in the passage zone 28 between the rollers 27 (Fig. 3d). The apex 31a passes through the rubber band and partially lifts it, allowing it to be placed in the recess 31b, and cutting continues from the midline until the first lateral edge of the rubber band is reached (FIG. 3e). The knife 30 cuts the elastomeric material by moving the knife between the two reinforcing cords 10 in a direction parallel to them. After that, the knife 30 comes back and while still moving in the “T” direction of cutting, but in the second side opposite the first, and the tip 31a of the cutting edge opposite to the one that has worked so far comes into contact with the rubberized the tape 15 is still in the raised part and in the area of the passage 28 between the rollers 27. The apex 31a partially raises the rubberized tape 15, placing it in the recess 31b, and continues to cut it from the midline until it reaches its second side th edge. Now the rubberized tape 15 will be divided into two segments (figa). One section 15a, located downstream of the cutting zone, has the aforementioned length “L”, while one section 15b, located downstream of the cutting zone, is wound on the reel 16. The tapering end 41a of the section 15a, located further downstream, relies only on one of the two rollers 27 of the mounting element 25, and the adjacent end 41b of the portion 15b, located closer along, rests on the other of these two rollers 27 (figa).

The second and third conveyor belts 20, 35 are driven while the first conveyor belt 19 is stationary, to move the segment 15a, located further downstream, to the forming drum 14 and placing it on the forming drum 14. During the first moments of this of the step, the tapering end 41a of the segment 15a located further downstream causes the corresponding roller 27 to rotate, while the other roller 27 remains stationary with the adjacent end 41b of the portion 15b located closer to x do (fig.4b).

The forming drum 14 is placed at a section 15a located further downstream, and the forming drum 14 rolls along it while ensuring the movement of the specified segment forward by means of the third conveyor belt 35 for winding the specified segment 15a in a certain way around the surface 14a of the forming drum 14, outer in the radial direction . The setting element 25 is omitted, and the cycle is repeated for each segment.

All the above movements are controlled, preferably completely automatically, by means of a control device that is functionally connected to the motors of conveyor belts 19, 20, 35, driving devices 25a of the mounting element 25, the knife motor 30, the sensor 37 and the corresponding acting device 37a, and, possibly, other appropriate sensors configured to determine the position of the rubberized tape 15 and the moving components of the device.

Claims (32)

1. A method of assembling tires for vehicle wheels, including: the formation of at least one component of the tire (2) on the forming drum (14), wherein the component is formed by:
feeding the rubberized tape (15) to the conveyor (18) along the direction (A) of the feed, coinciding with the longitudinal direction (X) of the passage of the specified rubberized tape (15), until it extends beyond the cutting zone provided in the conveyor (18) ), for a given length (L); wherein the rubberized tape (15) contains many parallel reinforcing cords (10) embedded in a matrix of elastomeric material (11) and having a slope at a given angle (α) relative to the longitudinal direction (X) of passage;
lifting the mounting element (25) located under the rubberized tape (15) and in the cutting zone, until the rubberized tape (15) rises;
moving the knife (30) located above the rubberized tape (15) and in the cutting zone, along the cutting direction (T) to cut and cut the rubberized tape (15) between two adjacent reinforcing cords (10) and over its entire width to form a segment ( 15a); and
overlapping segment (15A) on the forming drum (14);
in this case, before cutting, the first part of the rubberized tape (15), located along the installation element (25), is moved forward by a predetermined length (d) to reduce the tension of the rubberized tape (15) resulting from the lifting of the installation element (25). 2. The method according to claim 1, in which while moving the first part forward, the second part of the rubber tape (15), located along the installation element (25), is stationary. 3. The method according to claim 1 or 2, in which the movement of the first part forward includes: actuating the first part (19) of the conveyor (18), located along the installation element (25), regardless of the second part (20) of the conveyor ( 18) located downstream of the mounting element (25). 4. The method according to claim 1 or 2, in which the specified length (d) is essentially equal to the elongation of the rubberized tape (15) resulting from the lifting of the mounting element (25). 5. The method according to claim 1 or 2, wherein the predetermined length (d) is from about 10 mm to about 100 mm. 6. The method according to claim 1 or 2, in which, while moving forward, the rubberized tape (15) rolls on at least one support roller (27) belonging to the mounting element (25). 7. The method according to claim 1 or 2, wherein during movement along the cutting direction (T), the knife (30) passes between two support rollers (27) belonging to the mounting element (25). 8. The method according to claim 1, wherein after cutting, the segment (15a) of the rubberized tape (15) is moved from the cutting zone. 9. The method according to claim 8, in which during the movement from the cutting zone, the end (41a) of the segment (15a) just formed when cutting is rolled over one of the two supporting rollers (27). 10. The method according to claim 1 or 2, in which the rubberized tape (15) is displaced laterally to center it relative to the forming drum (14), which is located even further downstream. 11. The method according to claim 1 or 2, in which the superposition of the segment (15A) on the forming drum (14) includes:
winding a segment (15a) around a radially outer surface (14a) of the forming drum (14);
connection with each other of the opposite ends of the segment (15A). 12. The method according to claim 1 or 2, wherein the rubberized tape (15) is unwound from the bobbin (16). 13. The method according to claim 1 or 2, in which the component (2) of the tire is a belt tape. 14. The method according to claim 1 or 2, wherein the predetermined angle (α) is in the range from about 15 ° to about 35 °. 15. The method according to claim 1 or 2, in which the direction (T) of cutting parallel to the reinforcing cords (10). 16. A device for assembling tires for wheels of vehicles, comprising:
shaping drum (14);
a conveyor (18) forming a supporting surface (22) for the rubberized tape (15) and having a first part (19) and a second part (20) arranged in series along the feed direction (A);
a mounting element (25) located between the first part (19) and the second part (20), passing along the direction transverse to the supply direction (A), and configured to move in the vertical direction between the lowered position in which it is under the supporting surface (22), and a raised position in which he stands for the supporting surface (22); and
a knife (30) mounted above the conveyor (18) near the mounting element (25) and configured to move along a path (T) passing at an angle relative to the feed direction (A);
wherein the forming drum (14) is functionally connected to the conveyor (18) for receiving a piece (15a) of rubberized tape (15) cut by a knife (30);
moreover, the first part (19) of the conveyor (18) is configured to bring it into action independently of the second part (20);
wherein the mounting element (25) comprises a support (26) and at least one roller (27) mounted on the support (26). 17. The device according to clause 16, in which at least one roller (27) is a supporting roller. 18. The device according to clause 16 or 17, in which at least one roller (27) passes along the entire width of the conveyor (18). 19. The device according to clause 16 or 17, in which the mounting element (25) contains two rollers (27), the axis (Z-Z) of rotation of which are essentially sequentially aligned along the transverse direction. 20. The device according to claim 19, in which each of the two rollers (27) is installed with the possibility of free rotation on the support (26) independently of the other. 21. The device according to claim 19, in which two rollers (27) limit the passage (28) between them, intended for a knife (30). 22. The device according to item 16 or 17, in which each of the two parts (19, 20) contains a conveyor belt. 23. The device according to item 22, in which each of the two parts has a continuous supporting surface (23), on which the conveyor belt moves. 24. The device according to item 23, in which the continuous supporting surface (23) contains magnets (33). 25. The device according to paragraph 24, in which the magnets (33) are embedded in a continuous supporting surface (23). 26. The device according to clause 16 or 17, in which the inclined path (T) of the knife (30) and the direction (A) of the feed limit the angle (α) of inclination of from about 15 ° to about 35 °. 27. The device according to clause 16 or 17, in which the angle of inclination of the trajectory (T) is adjustable. 28. The device according to clause 16 or 17, in which the knife (30) has two opposite recesses (31b) located along the trajectory (T), passing at an angle, and made with cutting edges. 29. The device according to clause 16 or 17, containing a centering device (37, 37a), made with the possibility of biasing the conveyor (18) in the lateral direction to center the rubberized tape (18) relative to the forming drum (18), which is located even further downstream . 30. The device according to clause 29, in which the centering device (37, 37a) contains:
a sensor (37) located between the second conveyor belt (20) and the third conveyor belt (35) and configured to determine the position of the rubber band (15) in the lateral direction;
acting device (37a), functionally connected to the sensor (37) and affecting the conveyor (18). 31. The device according to clause 16 or 17, containing a bobbin (16) located along the conveyor (18) and carrying a rubber band (15) wound around it. 32. The device according to p. 31, containing a device (38) for pre-centering, located between the bobbin (16) and the conveyor (18) and which serves as a support for the rubberized tape (15); the device (38) for pre-centering is made with the possibility of its displacement in the lateral direction to adjust the position of the rubber tape (15) relative to the conveyor (18).

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