Valve stem repair kit and method

Abstract

A method for repairing damaged valve stem assemblies includes enlarging a bore within a body of a valve stem to form an enlarged bore portion and creating a conical hole in an end of the valve stem body around the enlarged bore portion. Internal threads are created within the enlarged bore portion, and a valve stem repair extension is installed in the enlarged bore portion. The valve stem repair extension has a beveled surface that mates with the conical hole to form a hermetic seal between the valve stem body and the valve stem repair extension. The steps of enlarging the bore and creating the conical hole may both be performed using a countersinking drill bit having a beveled cutting portion.

1 . A valve stem repair extension comprising:
 a. a generally cylindrical hollow body;   b. a threaded attachment portion on one end of said body for mating with a threaded bore in a damaged valve stem assembly;   c. an outer threaded portion on an end of said body opposite said threaded attachment portion for mating with a valve cap;   d. a valve core threaded into an inner threaded portion of said body; and   e. a beveled surface adjacent to said threaded attachment portion for mating with a conical hole in the threaded bore of the damaged valve stem assembly to create a hermetic seal between the valve stem repair extension and the valve stem assembly.   
     
     
         2 . The valve stem repair extension of  claim 1 , further comprising a valve cap received on said outer threaded portion of said body. 
     
     
         3 . The valve stem repair extension of  claim 1 , further comprising knurled portions for improving tactile handling of the valve stem repair extension during installation. 
     
     
         4 . The valve stem repair extension of  claim 1 , further comprising a cylindrical shank positioned between a knurled portion of said body and said threaded attachment portion. 
     
     
         5 . A method of repairing damaged valve stems comprising:
 a. enlarging a bore within a body of a valve stem to form an enlarged bore portion;   b. creating a conical hole in an end of the valve stem body around said enlarged bore portion;   c. creating internal threads within said enlarged bore portion; and   d. installing a valve stem repair extension in said enlarged bore portion, said valve stem repair extension having a beveled surface that mates with said conical hole to form a hermetic seal between said valve stem body and said valve stem repair extension.   
     
     
         6 . The method of  claim 5 , further comprising the step of removing any remaining portion of a damaged valve core from the valve stem prior to enlarging the bore to form an enlarged bore. 
     
     
         7 . The method of  claim 5 , wherein the steps of enlarging the bore and creating the conical hole are both performed using a countersinking drill bit having a beveled cutting portion. 
     
     
         8 . The method of  claim 5 , wherein the steps of enlarging the bore and creating the conical hole are both performed using a countersinking drill bit having a first cutting portion for forming the enlarged bore portion, and a second beveled cutting portion for removing a broken threaded portion of the body of the valve stem, and forming the conical hole. 
     
     
         9 . The method of  claim 5 , wherein the step of creating the internal threads is performed using a tap. 
     
     
         10 . The method of  claim 5 , wherein the step of installing a valve stem repair extension includes installing a valve stem repair extension having a body with a bore disposed therein, a threaded attachment portion at one end of the body adapted to mate with the enlarged bore portion of the valve stem, and a valve core within the bore. 
     
     
         11 . The method of  claim 10 , further comprising the step of applying a thread sealant to the threaded attachment portion prior to the step of installing the valve stem repair extension. 
     
     
         12 . A valve stem repair kit comprising:
 a. a valve stem repair extension having a beveled portion adjacent to a threaded attachment portion; and   b. a countersinking drill bit having a beveled cutting surface for forming a conical hole in a damaged valve stem body.   
     
     
         13 . The kit of  claim 12 , further comprising a valve stem core tool for removing an old broken valve core from a damaged valve stem assembly. 
     
     
         14 . The kit of  claim 12 , further comprising a tap for creating threads in a drilled-out valve stem assembly. 
     
     
         15 . The kit of  claim 12 , further comprising a thread sealant. 
     
     
         16 . The kit of  claim 12 , wherein said valve stem repair extension includes a generally cylindrical hollow body; a threaded attachment portion on one end of said body for mating with a threaded bore in a damaged valve stem assembly;
 an outer threaded portion on an end of said body opposite said threaded attachment portion for mating with a valve cap; a valve core threaded into an inner threaded portion of said body; and a beveled surface adjacent to said threaded attachment portion for mating with a conical hole in the threaded bore of the damaged valve stem assembly to create a hermetic seal between the valve stem repair extension and the valve stem assembly.