Method and apparatus to vent a mold

Abstract

A method and apparatus for venting a mold for vulcanizing a tire is provided. The mold comprises a plurality of tread segments for forming the tread on a green tire, wherein each of said tread segments further comprises an outer cavity plate having an interior surface and an exterior surface, the cavity plate having a plurality of channels. Each of the channels has a vent hole extending from the channel to the exterior surface of the outer cavity plate, and a rib mounted over the channel. The adjoining surface of the rib mating with the interior surface of the cavity plate, wherein one of the mating surfaces has a roughened surface forming a vent passageway with the interior surface of the cavity plate for venting mold gasses from the interior of the mold to the exterior of the mold. The invention may further include a blade and blade passageway wherein the blade outer surface has a rough outer surface for forming a vent passageway with the blade passageway.

1 . A mold for vulcanizing a tire, the mold comprising a plurality of tread segments for forming the tread on a green tire, wherein the tread segments can be assembled side by side circumferentially about the green tire, each of said tread segments further comprised of an outer cavity plate having an interior surface and an exterior surface, said cavity plate having a plurality of channels, each of said channels having a vent hole extending from the channel to the exterior surface of the outer cavity plate; each of said channel having a rib mounted thereover, the adjoining surface of said rib mating with the interior surface of the cavity plate, wherein the adjoining surface located about the perimeter of said rib has a roughened surface forming a vent passageway with the interior surface of the cavity plate for venting mold gasses from the interior of the mold to the exterior of the mold.  
     
     
         2 . The mold of  claim 1  wherein the adjoining surface of said channel mating with the interior surface of the cavity plate is located radially outward of the external contour of the tire.  
     
     
         3 . The mold of  claim 1  wherein adjoining surface of said rib has a roughened surface on the order of about 10 to about 40 mils.  
     
     
         4 . The mold of  claim 1  wherein adjoining surface of said rib has a roughened surface on the order of about 20 mils.  
     
     
         5 . The mold of  claim 1  wherein adjoining surface of said rib has a roughened surface formed of peaks and valleys, wherein the peaks are oriented perpendicular to the adjoining surface of said rib.  
     
     
         6 . The mold of  claim 1  wherein adjoining surface of said rib has a roughened surface having a scalloped pattern.  
     
     
         7 . A mold for vulcanizing a tire, the mold comprising a plurality of tread segments for forming the tread on a green tire, wherein the tread segments can be assembled side by side circumferentially about the green tire, each of said tread segments further comprised of an outer cavity plate having an interior surface and an exterior surface, said cavity plate having a plurality of channels, each of said channels having a vent hole extending from the channel to the exterior surface of the outer cavity plate; each of said channel having a rib mounted thereover, the adjoining surface of said rib mating with the interior surface of the cavity plate, wherein the interior surface of the cavity plate has a roughened surface forming a vent passageway with the adjoining surface of the ribs for venting mold gasses from the interior of the mold to the exterior of the mold.  
     
     
         8 . The mold of  claim 7  wherein the adjoining surface of said rib mating with the interior surface of the cavity plate is located radially outward of the external contour of the tire.  
     
     
         9 . The mold of  claim 7  wherein the interior surface of said cavity plate has a roughened surface on the order of about 10 to about 40 mils.  
     
     
         10 . The mold of  claim 7  wherein the interior surface of said cavity plate has a roughened surface on the order of about 20 mils.  
     
     
         11 . The mold of  claim 7  wherein the interior surface of said cavity plate has a roughened surface formed of peaks and valleys, wherein the peaks are oriented perpendicular to the interior surface of said cavity plate.  
     
     
         12 . The mold of  claim 7  wherein the interior surface of said cavity plate has a roughened surface having a scalloped pattern.  
     
     
         13 . A method of making a tread segment for use in a mold, the tread segment having a plurality of ribs and lands, the method comprising the steps of: 
 providing a cavity contour plate having an interior surface and an exterior surface,    roughing the interior surface of the cavity contour plate to a surface roughness of about 10 to about 40 mils,    forming a plurality of channels in the interior surface of the cavity contour plate at the location of the ribs;    forming a vent hole in each channel to the exterior surface of the cavity contour plate,    securing an inner surface of a tread profile plate to the interior surface of the cavity contour plate at the location of the ribs, and forming the ribs from the tread profile plate.    
     
     
         14 . A method of making a tread segment for use in a mold, the tread segment having a plurality of ribs and lands, the method comprising the steps of: 
 providing a cavity contour plate having an interior surface and an exterior surface,    forming a plurality of channels in the interior surface of the cavity contour plate at the location of the ribs;    forming a vent hole in each channel to the exterior surface of the cavity contour plate,    providing a tread profile plate having an interior surface,    roughening the interior surface of the tread profile plate,    securing an inner surface of a tread profile plate to the interior surface of the cavity contour plate at the location of the ribs, and forming the ribs from the tread profile plate.    
     
     
         15 . A mold for vulcanizing a tire, the mold comprising a plurality of tread segments for forming the tread on a green tire, wherein the tread segments can be assembled side by side circumferentially about the green tire, each of said tread segments further comprised of a cavity plate having an interior surface and an exterior surface, said cavity plate having a plurality of slots on the interior surface, one or more blades secured within each slot, an outer surface of said blade mates with an inner surface of said slot, wherein one of said mating surfaces is roughened relative to the other mating surface forming a vent passageway for venting mold gasses from the interior of the mold to the exterior of the mold.  
     
     
         16 . The mold of  claim 15  wherein the blades have a roughened surface on the order of about  10  to about  40  mils.  
     
     
         17 . The mold of  claim 15  wherein the inner surface of said slot has a roughened surface on the order of about 10 to about 40 mils.  
     
     
         18 . The mold of  claim 15  wherein the blades have a roughened surface on the order of about 20 mils.  
     
     
         19 . The mold of  claim 15  wherein the blades have a roughened surface having a scalloped pattern.  
     
     
         20 . A method of making a tread segment for use in a mold, the tread segment having a plurality of ribs and lands, the method comprising the steps of: 
 providing a cavity contour plate having an interior surface and an exterior surface,    forming a tread pattern of channels on the interior surface of the cavity contour plate;    forming one or more slots on the interior surface of the cavity contour plate;    mounting a blade in each slot, wherein the outer surface of the blade has a roughened surface.    
     
     
         21 . A method of making a tread segment for use in a mold, the tread segment having a plurality of ribs and lands, the method comprising the steps of: 
 providing a cavity contour plate having an interior surface and an exterior surface,    forming a tread pattern of channels on the interior surface of the cavity contour plate;    forming one or more slots on the interior surface of the cavity contour plate;    mounting a blade in each slot, wherein the inner surface of the slot has a roughened surface.