| 摘要 |
1300764 Coated bolt USM CORP 28 April 1970 [2 May 1969] 20384/70 Heading B2E [Also in Division F2] A self locking bolt 10 has a patch 12 of tough, resilient, thermoplastic resin adhered to a portion of the threaded surface 14 thereof, the resin being in the form of a series of spaced mounds 20 in the valleys 18 of the threads with the spaces between the mounds being substantially free of resin and the radial thickness of the mounds being at least 75% of the maximum clearance between the threads of the bolt and those of a mating internally threaded member. The bolt may be produced by first applying a coat of resin primer 16 (e.g. a 10% by weight solution of an alcohol soluble nylon and an epoxy resin) to enhance the adherence of the resin and then heating the bolt to a temperature above the softening point of the resin and spraying a stream of fine particles of the resin on the bolt. The rate of supply may be between 5 and 50% of that rate which would produce a uniform coating of resin. The powder particles become fused by heat from the threads and are then cooled to form a firmly adherent resin deposit. Nylon is a preferred thermoplastic resin for use in this process. |
