Methods and apparatus for applying cushion gum to a tire casing

Abstract

Methods, computer programs, and apparatus for applying a layer of cushion gum to a tire casing in preparation for the retreading of the tire casing, the steps of the methods including selecting one of a plurality recipes for applying cushion gum based on one of a size, model and shape of the tire casing; pressurizing the tire casing to a predetermined pressure based on the recipe; crushing the tire casing by an extruder head a predetermined percentage of the tire casing radius or a predetermined distance, the predetermined percentage based on the recipe; and extruding the cushion gum from the extruder head. The extruder head may be translatable by way of a screw drive.

1 . A cushion gum applicator, comprising:
 a cushion gum extruder having an extruder head;   a tire casing mount for mounting and rotating a tire casing;   a controller comprising a processor and a memory storage device that stores instructions readable by the processor, the instructions including:
 selecting instructions for selecting one of a plurality of recipes for applying cushion gum based on one of a size, model and shape of the tire casing; 
 pressurizing instructions for pressurizing the tire casing to a predetermined pressure based on the selected recipe; 
 crushing instructions for crushing the tire casing with an extruder head a predetermined amount of the tire casing radius, the predetermined amount based on the selected recipe; 
 extruding instructions for extruding the cushion gum from the extruder head onto the tire casing as the tire casing rotates and as the tire casing is crushed according to the crushing instructions. 
   
     
     
         2 . The cushion gum applicator of  claim 1 , where the crushing instructions further include translating one of the tire casing and the extruder head a distance to contact the other, the distance being based on the selected recipe. 
     
     
         3 . The cushion gum applicator of  claim 1 , where the plurality of recipes providing one or more combinations of one or more predetermined pressures, extruder crush distances, extruder stop distances, and extruder smear distances for applying cushion gum to a tire casing. 
     
     
         4 . The cushion gum applicator of  claim 1 , further comprising:
 a base for supporting the extruder, wherein the extruder translates relative to the base toward and away from the tire casing mount; and,   a screw drive associated with the base and operably attached to the extruder, the screw drive translating the extruder relative to the base.   
     
     
         5 . The cushion gum applicator of  claim 1 , where the extruder head or the tire casing translates by a screw drive. 
     
     
         6 . The cushion gum applicator of  claim 5 , where the extruder head translates. 
     
     
         7 . The cushion gum applicator of  claim 1 , where the crushing instructions for crushing the tire casing crushes the tire casing from about two percent to about ten percent of the tire casing radius based upon the recipe selected. 
     
     
         8 . The cushion gum applicator of  claim 1 , where the crushing instructions for crushing the tire casing crushes the tire casing from about three percent to about eight percent of the tire casing radius based upon the recipe selected. 
     
     
         9 . The cushion gum applicator of  claim 1 , where the instructions further comprise, measuring instructions for measuring a circumference of the tire casing; and
 calculating parameters for applying the cushion gum, the parameters being based on the measured circumference.   
     
     
         10 . The cushion gum applicator of  claim 9 , where the calculating parameters include at least one of the cushion gum value, rate of rotation of the tire casing, and rate of extrusion of the cushion gum. 
     
     
         11 . The cushion gum applicator of  claim 9 , where the instructions further include:
 partial pressurization instructions for partially inflating the tire casing to a pressure less than the predetermined pressure prior to measuring the circumference of the tire casing by way of the measuring instructions, the measurement of the tire casing circumference by the way of the measuring instructions initiating while the tire casing is partially inflated, where pressurizing of the tire casing by way of the pressurization instructions proceeds from the partially inflated tire casing.   
     
     
         12 . The cushion gum applicator of  claim 9 , where the measuring instructions of the tire casing operate an encoder associated with a wheel, the wheel selectively engaging the tire casing and rotating with the tire casing when measuring the tire casing. 
     
     
         13 . The cushion gum applicator of  claim 1 , where:
 the extruding instructions provide that the cushion gum is extruded about the tire casing circumference to a predetermined stop distance less than three hundred sixty degrees about the tire casing, the predetermined extrusion stop distance being based upon the selected recipe,   the instructions further including:   smearing instructions for smearing the cushion gum remaining at an extruder head-tire casing interface at least about the remainder of the tire casing circumference by a predetermined smear distance based upon the selected recipe, the smearing being performed after extruding the cushion gum from the extruder head about the tire casing circumference to a predetermined stop distance.   
     
     
         14 . The cushion gum applicator of  claim 1 , where the instructions further include:
 maintaining instructions for substantially maintaining the predetermined tire casing pressure during extrusion of the cushion gum.   
     
     
         15 . The cushion gum applicator of  claim 1 , the instructions further comprising:
 measuring instructions for measuring a circumference of the tire casing;   measuring instructions for measuring a thickness of material above any tire casing belts about the circumference of the tire casing;   determining instructions for determining the thinnest portion of the material based upon the thickness of material measured in the step of measuring a thickness of material; and,   indexing instructions for indexing the tire casing to initiate the extruding instructions generally at the thinnest portion of the material thickness.   
     
     
         16 . The cushion gum applicator of  claim 11 , where the pressurizing instructions partially inflate the tire casing to a pressure within at least 10% of the predetermined pressure.