Process and plant for building green tyres for vehicle wheels

Abstract

A plant and a process for building different types of green tyres for vehicle wheels for each tyre size, through the use of elementary semi-finished products, includes: a) building a carcass structure of a green tyre, the carcass structure including at least one carcass ply and a pair of annular anchoring structures; and b) building a crown structure of a green tyre, the crown structure including at least one belt structure and a tread band; wherein at least one between the building of the carcass structure and the building of the crown structure includes: c) providing at least one first feeding unit of a first elementary semi-finished product and one second feeding unit of a second elementary semi-finished product, the at least one first and one second elementary semi-finished products being different from one another; and d) building at least one portion of a structural component of the tyre being processed, starting from at least one of the first and second elementary semi-finished products, in one work station fed by the first and second feeding units of the first and second elementary semi-finished products.

1 - 38 . (canceled) 
     
     
         39 . A process for building different types of green tyres for vehicle wheels for each tyre size, through the use of elementary semi-finished products, in a building plant comprising a plurality of work stations, comprising:
 a) building a carcass structure of a green tyre, said carcass structure comprising at least one carcass ply and a pair of annular anchoring structures;   b) building a crown structure of a green tyre, said crown structure comprising at least one belt structure and a tread band;   c) providing, in each of at least two work stations, at least one first feeding unit of a first elementary semi-finished product and one second feeding unit of a second elementary semi-finished product, said at least one first and one second elementary semi-finished products being different from one another; and   d) building, in each of said at least two work stations, at least one portion of a structural component of a tyre being processed starting from at least one of said first and second elementary semi-finished products.   
     
     
         40 . The process according to  claim 39 , wherein the building of at least one portion of a structural component of the tyre being processed from at least one of said first and second elementary semi-finished products, in each of said at least two work stations comprises at least one of the following:
 applying a first belt strip;   applying a second belt strip in a position radially external to said first belt strip;   applying at least one first layer of textile or metal cords, arranged circumferentially in a position radially external to the radially external second belt strip, and applied at least at axially external portions thereof;   applying a first carcass ply; and   applying a second carcass ply in a position radially external to said first carcass ply.   
     
     
         41 . The process according to  claim 39 , wherein building of the crown structure comprises:
 building a tread band through winding of at least one continuous elongated element of elastomeric material on a surface radially external to a forming drum according to adjacent and/or radially juxtaposed coils.   
     
     
         42 . The process according to  claim 41 , wherein the building of said tread band is carried out through the use of at least two continuous elongated elements of different elastomeric materials. 
     
     
         43 . The process according to  claim 39 , wherein the building of a tyre being processed is carried out on at least one forming drum. 
     
     
         44 . The process according to  claim 43 , wherein:
 the building of the carcass structure of a tyre being processed is carried out on a first forming drum in at least one carcass structure building line; and   the building of the crown structure of the tyre being processed is carried out on at least one second forming drum in at least one crown structure building line.   
     
     
         45 . The process according to  claim 39 , further comprising:
 e) toroidally shaping the carcass structure by assembling thereof with the crown structure in at least one assembling and shaping work station of a tyre being processed.   
     
     
         46 . The process according to  claim 44 , wherein each carcass structure is associated with a respective first forming drum on which said carcass structure is built up, until shaping and assembling of the tyre being processed is finished. 
     
     
         47 . The process according to  claim 39 , further comprising:
 arranging said at least one first and one second elementary semi-finished product in an elementary semi-finished product arranging line.   
     
     
         48 . The process according to  claim 47 , further comprising:
 transferring said at least one first and one second elementary semi-finished product into respective temporary storage units.   
     
     
         49 . The process according to  claim 39 , further comprising:
 transferring said at least one first and one second elementary semi-finished products from temporary storage units into corresponding feeding units of the corresponding work stations.   
     
     
         50 . The process according to  claim 39 , wherein a tyre being processed is transferred from one work station to a next work station by means of at least one robotised arm. 
     
     
         51 . A plant for building different types of green tyres for vehicle wheels for each tyre size, comprising feeding elementary semi-finished products into a plurality of work stations, comprising:
 at least one first and one second work stations, each fed by at least one first and one second elementary semi-finished products which are different from one another; and   at least one first feeding unit of said first elementary semi-finished product and one second feeding unit of said second elementary semi-finished product for each of said work stations fed by said at least one first and one second elementary semi-finished product, wherein:   each of said first and second work stations is capable of being adapted to build at least one portion of a structural component of the tyre being processed starting from at least one elementary semi-finished product selected from said first and second elementary semi-finished products fed into the work station.   
     
     
         52 . The plant according to  claim 51 , comprising at least one temporary storage unit of elementary semi-finished products. 
     
     
         53 . The plant according to  claim 51 , comprising four work stations fed by at least one first and one second elementary semi-finished products. 
     
     
         54 . The plant according to  claim 51 , wherein two different elementary semi-finished products are fed into each of said first and second work station. 
     
     
         55 . The plant according to  claim 51 , wherein each work station fed by said first and second elementary semi-finished products is provided with corresponding feeding units of semi-finished products. 
     
     
         56 . The plant according to  claim 51 , further comprising an elementary semi-finished product arranging line. 
     
     
         57 . The plant according to  claim 51 , wherein at least one of said at least one first and one second work stations fed by at least one first and one second elementary semi-finished product comprises one of the following work stations:
 a first belt application work station provided with devices for applying at least one first belt strip;   a second belt application work station provided with devices for applying a second belt strip in a position radially external to said first belt strip;   a cord application work station provided with devices for applying at least one first layer of textile or metal cords, arranged circumferentially on a radially external belt strip, applied at least at axially external portions thereof; and   a ply application work station provided with devices for applying at least one first carcass ply.   
     
     
         58 . The plant according to  claim 51 , further comprising at least one forming drum whereon the tyre is built. 
     
     
         59 . The plant according to  claim 51 , further comprising:
 at least one carcass structure building line on a first forming drum, said carcass structure comprising at least one carcass ply and a pair of annular anchoring structures; and   at least one crown structure building line on a second forming drum, said crown structure comprising at least one belt structure and a tread band.   
     
     
         60 . The plant according to  claim 59 , further comprising: at least one assembling and shaping work station of the tyre being processed capable of being adapted to shape said carcass structure by assembling thereof at said crown structure so as to obtain a green tyre. 
     
     
         61 . The plant according to  claim 51 , further comprising at least one work station of the following type:
 at least one tread band building work station, provided with at least one application device of said tread band capable of being adapted to deposit a continuous elongated element of elastomeric material by winding thereof onto a surface radially external to a forming drum, according to adjacent and/or radially juxtaposed coils.   
     
     
         62 . The plant according to  claim 61 , wherein said tread band building work station comprises at least two of said application devices, each dispensing a continuous elongated element of elastomeric material different from each other. 
     
     
         63 . The plant according to  claim 51 , further comprising devices for transferring the tyre being processed from one work station to a next work station. 
     
     
         64 . The plant according to  claim 63 , wherein said transfer devices comprise at least one robotised arm. 
     
     
         65 . A method for building different types of green tyres for vehicle wheels for each tyre size, from elementary semi-finished products, in a building plant comprising a plurality of work stations comprising:
 feeding n k  different elementary semi-finished products into each k-th work station of m work stations fed by said n k  elementary semi-finished products;   building, in each k-th work station, at least one portion of a structural component of a tyre being processed starting from at least one elementary semi-finished product selected from said n k  elementary semi-finished products fed into the work station, said different types of green tyres for each size being equal to
   π k= 1 ,m n   k  
 
   
       m and each n k  being greater than or equal to 2. 
     
     
         66 . The method according to  claim 65 , wherein m is greater than or equal to 3. 
     
     
         67 . The method according to  claim 65 , wherein m is equal to 4. 
     
     
         68 . The method according to  claim 65 , wherein n k  is equal to 2 in each k-th work station. 
     
     
         69 . The method according to  claim 65 , wherein at least one n k  of a k-th work station is greater than or equal to 3. 
     
     
         70 . The method according to  claim 65 , further comprising:
 storing elementary semi-finished products, previously arranged, in respective temporary storage units of elementary semi-finished products.   
     
     
         71 . The method according to  claim 70 , further comprising:
 transferring said elementary semi-finished products, arranged in an elementary semi-finished products arranging line, into the respective temporary storage units.   
     
     
         72 . The method according to  claim 70 , further comprising:
 transferring said n k  elementary semi-finished products from the temporary storage units into corresponding semi-finished product feeding units of the corresponding k-th work stations.   
     
     
         73 . The method according to  claim 65 , wherein building of at least one portion of a structural component of a tyre being processed starting from at least one elementary semi-finished product selected from said n k  elementary semi-finished products fed into the k-th work station comprises:
 winding at least one continuous elongated element of elastomeric material onto a surface radially external to a forming drum according to adjacent and/or radially juxtaposed coils.   
     
     
         74 . The method according to  claim 73 , comprising two continuous elongated elements comprising different elastomeric materials. 
     
     
         75 . The method according to  claim 65 , wherein each elementary semi-finished product fed into a k-th work station is different from each elementary semi-finished product fed into a different k-th work station. 
     
     
         76 . The method according to  claim 65 , wherein each elementary semi-finished product fed into a k-th work station is different from all remaining elementary semi-finished products fed into remaining work stations of m work stations.