Semi-pneumatic mine service tire

Abstract

A semi-pneumatic tire assembly including a tire casing 22 and a lining 26 is provided. The lining 26 includes a contoured inward surface 30 defining an inflation chamber 18 about an associated wheel rim. The lining 26 minimizes the risk of puncture damage from an object penetrating the tire casing 22 while allowing pneumatic cushioning of the ride and cooler running temperatures as compared to solid-fill tires. Additionally, the semi-pneumatic tire will carry the same load or more than the same tire filled with permafoam and/or solid urethane foam wingfil. The tire assembly is formed by injecting a curable, lining-forming material 96 into a cavity 57 defined between the tire casing 22 and a molding member 50. The molding member 50 includes a contoured outer surface 54 which molds the inward surface of the lining 26. The molding member 50 may be an inflatable airbag 100 retained in the tire assembly during service. Alternately, the molding member 50 may be a solid core 114 which is removed prior to mounting the tire casing 22 and lining 26 on the associated rim.

1 . A method of forming a tire assembly for mounting on an associated rim, the tire assembly including a tire casing having a tread region, first and second shoulder regions, a pair of beads, and an inner concave surface, the tire assembly her including a lining adjacent the inner surface of the tire casing, the method being characterized by the steps of: 
 positioning an annular molding member in an interior of the tire casing, the molding member having a first contoured surface spaced from the inner concave surface of the tire casing;    mounting the tire casing and molding member onto a rim-like member, the rim-like member having a pair of spaced bead receiving areas, an annular rim band, and a rim valve;    seating the beads on the bead receiving areas of the rim-like member by introducing air through the rim valve so that a first cavity is defined between the inner concave surface of the tire casing and the first surface of the molding member;    injecting a flowable, curable material into the first cavity through the rim valve; and,    forming the lining by curing the material, the lining filling the first cavity and including an inward surface mating with the first surface of the molding member and an outward surface mating with the inner surface of the tire casing.    
     
     
         2 . The method of  claim 1  further comprising the steps of: 
 drilling a vent hole in the tire casing at a centerline thereof in a position aligned with the rim valve;  
 injecting the flowable material into the first cavity until the material passes through the vent hole;  
 plugging the vent hole; and,  
 continuing to inject the flowable material until a predetermined internal pressure is reached.  
 
     
     
         3 . The method of  claim 2  further comprising the step of: 
 vertically mounting the tire casing and rim-like member so that the rim valve is in a downward position and the vent hole is positioned perpendicular to the horizontal before the step of injecting the flowable material.  
 
     
     
         4 . The method of  claim 1  wherein the step of forming the lining by curing the material comprises: 
 arranging the tire casing and rim-like member so that the tire's mid-circumferential plane is in a horizontal position for a predetermined time period.  
 
     
     
         5 . The method of  claim 4  wherein the predetermined time period is between 12 hours and 36 hours.  
     
     
         6 . The method of  claim 1  wherein the molding member comprises an inflatable airbag member having an airbag valve, the method further comprising the step of: 
 inflating the airbag member to a predetermined configuration after the step of mounting the tire casing and molding member onto the rim-like member.  
 
     
     
         7 . The method of  claim 1  wherein the molding member comprises a solid core member having an outer shell comprising a first material and an interior comprising a second material.  
     
     
         8 . An annular molding member for molding an interior surface of a lining for a semi-pneumatic tire, the molding member characterized by: 
 a body having a first contoured surface, the first contoured surface including a tread-underlying portion, first and second shoulder-underlying portions, and first and second bead-underlying portions, the tread-underlying portion being generally linear in cross-section, the shoulder underlying portions being located on either side of the tread-underlying portion and being convex in cross-section, and the bead-underlying portions being adjacent the shoulder underlying portions and being concave in cross-section.    
     
     
         9 . The molding member of  claim 8  wherein the body comprises an inflatable airbag member.  
     
     
         10 . The molding member of  claim 8  wherein the body comprises a solid core member having an outer shell comprising a first material and an interior comprising a second material.  
     
     
         11 . A tire assembly for mounting on an associated rim, the tire assembly including a casing having a tread region, first and second shoulder regions, a pair of beads and an inner concave surface, and a lining, the lining being radially inwardly of the casing and having a radially outward surface adjacent the inner concave surface and mating therewith, the tire assembly being characterized by: 
 a contoured radially inward surface of the lining, the inward surface being substantially parallel to the tread region in a tread-underlying region, concave in first and second shoulder-underlying regions, and convex in first and second bead-underlying regions.    
     
     
         12 . The tire assembly of  claim 11  wherein the lining includes a first cross-sectional thickness T 1  in the tread-underlying region and a second cross-sectional thickness T 2  in the bead-underlying regions.  
     
     
         13 . The tire assembly of  claim 11 , wherein T 1  is at least 2.0 inches (5.08 cm).  
     
     
         14 . The tire assembly of  claim 11 , wherein T 2  is between 0.5 inches (1.27 cm) and 0.8 inches (2.03 cm).  
     
     
         15 . The tire assembly of  claim 11  wherein the lining occupies between forty percent and eighty percent of an interior volume defined by the inner surface of the casing.  
     
     
         16 . In combination, a tire assembly and a rim, the tire assembly including a tire casing having a tread region, first and second shoulder regions, a pair of beads and an inner concave surface, and a lining, the lining being radially inwardly of the casing and having a radially outward surface adjacent the inner concave surface and mating therewith, the rim including a pair of spaced bead receiving areas and a rim band, each of the beads being seated on the bead receiving areas, the combination being characterized by: 
 a contoured radially inward surface of the lining, the inward surface being substantially parallel to the tread region in a tread-underlying region, concave in first and second shoulder-underlying regions, and convex in first and second bead-underlying regions, the inward surface providing an outward boundary to an annular cavity encircling the rim band.    
     
     
         17 . The combination of  claim 16  wherein the lining occupies between forty percent and eighty percent of an interior volume defined by the inner surface of the casing.  
     
     
         18 . The combination of  claim 16  further comprising: 
 a hollow, annular, toroidal airbag member disposed within the annular cavity; and,  
 an airbag valve, the airbag member being inflatable by introducing air through the airbag valve.  
 
     
     
         19 . The combination of  claim 16  further comprising: 
 an annular spacer being adjacent said rim and positioned between said contoured surface of said lining and one of said pair of beads for separating said contoured surface from said one of said pair of beads.  
 
     
     
         20 . The combination of  claim 19  wherein said spacer comprises: 
 a series of stand off buttons defining a series of gaps therebetween.