Patent ID: 6972137
Filing Date: 2005-12-06
Classification: B05B,B05C,F16B

Abstract:
1. A method for the application of a fluoropolymer coating to the threads of an internally threaded fastener, said fastener having a body and a threaded bore extending axially to opposing ends of the body to thereby define opposing first and second openings in the fastener, said method comprising the steps of: moving the fastener along a path of travel with its threaded bore in a predetermined orientation; closing the first opening of the fastener; directing an air stream carrying entrained fluoropolymer powder through the second opening and into the bore of the fastener while the first opening is closed, said air stream emanating from a nozzle having a pressurized air supply and located at a position adjacent the fastener path of travel and outside the axial extent of the fastener bore and wherein said nozzle is stationary while the air stream with the entrained fluoropolymer powder is directed into the fastener, thereby forming a fluoropolymer powder coating on the threads of the fastener; and heating the fluoropolymer powder coating to form a generally continuous fluoropolymer film on the threads of the fastener.