Method and apparatus for tread belt assembly

Abstract

A method of building and transferring a tread 12 or a tread belt reinforcing assembly 14 on a building drum 10 is disclosed. The steps include applying at least one uncured tread component 12, 14 onto a radially collapsible building drum 10 , inserting the at least one uncured tread component 12 and the radially collapsible building drum 10 into an open segmented mold 2 wherein a plurality of mold tread forming segments 4 are radially expanded; contracting the plurality of mold tread forming segments 4 pressing into the at least one uncured tread component 12, 14 ; collapsing the building drum 10 ; and removing the building drum 10 thereby transferring the at least one uncured tread component 12, 14 into the mold. The preferred building drum apparatus 10 has a portable radially expandable and axially rotatable support means 20 ; a drive means 30 for rotating the support means 20 about the axis, a plurality of arcuate or straight segments 22 slidably mounted over the support means, the plurality of arcuate or straight segments 22 forming an annular building surface 24 ; a means 40 for radially expanding and contracting the radially expandable and axially rotatable support means; a means for receiving and accepting the tread or tread belt assembly while mounted on the plurality of arcuate or straight segments 22 mounted onto the portable support means 20 , the receiving means 2 being a segmented mold 2 with radially movable tread forming segments 4.

What is claimed is:  
     
         1 . A method of building and transferring a tread or a tread belt reinforcing assembly on a tire building drum, the method comprising the steps of: 
 applying at least one uncured tread component onto a radially collapsible building drum;    inserting the at least one uncured tread component and the radially collapsible building drum into an open segmented mold wherein a plurality of mold tread forming segments are radially expanded;    contracting the plurality of mold tread forming segments pressing into the at least one uncured tread component;    collapsing the building drum;    removing the building drum thereby transferring the at least one uncured tread component into the mold.    
     
     
         2 . The method of  claim 1  further comprises the steps of: 
 inserting a tire carcass into the mold;  
 closing the mold;  
 expanding the carcass under pressure forcing the carcass into contact with the at least one uncured tread component forming a tire assembly;  
 curing the tire assembly.  
 
     
     
         3 . The method of  claim 1  further comprises the step of: 
 heating the at least one uncured tread component to a temperature above ambient prior to closing the segments and wherein the at least one uncured tread component is warm and softened as the segments press into the tread.  
 
     
     
         4 . The method of  claim 1  wherein the step of applying at least one uncured tread component includes: 
 applying one or more cord reinforced belt, breaker, underlay or overlay layers onto the building drum prior to applying one or more layers or strips of uncured tread rubber to form a tread belt reinforcing assembly.  
 
     
     
         5 . An apparatus for building and transferring a tread or tread belt reinforcing assembly comprises: 
 a radially expandable and axially rotatable support means;    a drive means for rotating the support means about the axis;    a plurality of arcuate or straight segments slidably mounted over the support means, the plurality of arcuate or straight segments forming an annular building surface;    a transfer means for removing the plurality of arcuate or straight segments from the support means and wherein the transfer means provides radial support for the plurality of arcuate or straight segments when the support means is contracted.    
     
     
         6 . The apparatus of  claim 5  further comprises: 
 a means for radially expanding and contracting the radially expandable and axially rotatable support means.  
 
     
     
         7 . The apparatus of  claim 6  further comprises: 
 a means for receiving and for accepting the tread or tread belt assembly while mounted on the plurality of arcuate or straight segments mounted onto the support means, the receiving means being a segmented mold with radially movable tread forming segments.  
 
     
     
         8 . An apparatus for building and transferring a tread or tread belt reinforcing assembly comprises: 
 a portable radially expandable and axially rotatable support means;    a drive means for rotating the support means about the axis;    a plurality of arcuate or straight segments slidably mounted over the support means, the plurality of arcuate or straight segments forming an annular building surface;    a means for radially expanding and contracting the radially expandable and axially rotatable support means;    a means for receiving and accepting the tread or tread belt assembly while mounted on the plurality of arcuate or straight segments mounted onto the portable support means, the receiving means being a segmented mold with radially movable tread forming segments.    
     
     
         9 . The apparatus of  claim 8  further comprises a plurality of arcuate gap spanners interposed between each adjacent pair of arcuate or straight segments and wherein each arcuate segment has a gap of at least 0.050 (1.25 mm) in the radially expanded position, the gap spanners providing a radially outer surface which bridges between and overlaps pairs of adjacent segments.