Abstract:
A process and apparatus are provided for the application of a fluoropolymer coating to the threads of an internally threaded fastener. The fastener has a body and a threaded bore extending to opposing ends of the body to define opposing first and second openings in the fastener. The fastener is moved on a conveyor along a path of travel with its threaded bore in a predetermined orientation. As the fastener moves along its path of travel, the first opening is closed by means of an obstructing member, while an air stream carrying entrained fluoropolymer powder is directed from a nozzle through the second opening and into the threaded bore. The nozzle is stationary and is located at an axially displaced position relative to the second opening of the fastener and immediately adjacent the conveyor. Preferably, the nozzle includes a diffuser which directs the air stream and entrained fluoropolymer powder into the fastener bore in a diverging pattern. After the fluoropolymer powder is deposited onto the threads of the fastener, the conveyor moves the fastener through a heating station where the fluoropolymer powder is raised to its melting temperature causing it to melt and fuse into a generally continuous film covering the fastener's threads.
Abstract:
This invention describes self-locking threaded fasteners having a patch or patches of fused high-temperature-resistant resin adhered to a portion of the threads, providing self-locking capabilities at temperatures above 400.degree. F., well beyond the range of temperatures attainable using prior art patch materials such as nylon. A process for making such fasteners by spraying finely-divided high-temperature-resistant resin powder onto the threads of a fastener also is claimed.
Abstract:
An apparatus and method for applying locking material to an area of a fastener adapted for internal threading. The apparatus includes a support structure for moving a succession of internally threadable fasteners with support structure recesses positioning the fasteners for treatment. The fastener opening is filled with locking material and the fastener heated to soften the locking material and cause adherence to the internal walls of the fastener. A clearance pin can be used to selectively clear a passageway through the locking material either before or after the heating step. A gas pressure source directs a gas stream toward the opening of the fastener to form a passageway through the locking material attached to the fastener.
Abstract:
An apparatus for applying a coating to the head-shank junction of externally threaded fasteners in an automated fashion. The fasteners are positioned, head down, on rotating part holders positioned about the periphery of a rotating disc. The part holders may be magnetic or other forms, and are adapted to maintain the fasteners in a generally fixed position during their movement. The fasteners are pre-heated at a heating station during their rotational movement on the disc. A dispenser is then used to apply the coating to the articles, in timed sequence to the movement of the articles. In this fashion, a coating can be applied to selected portions of the entire periphery of the head-shank junction. A method for applying a coating to the head-shank junction of externally threaded fasteners in an automated fashion also forms part of the present invention.
Abstract:
A fastener, and a process and apparatus for coating fasteners, in which a resin type material is applied to the fastener is disclosed. A stream of resin type material is directed to each fastener and the threads of each of the fasteners, the threads may be covered over an arcuate variable length including complete 360.degree. coverage. The resin type material applied may be a masking material, a lubricating material and/or an insulating material enabling an accurate and consistent torque-tension characteristic to be maintained during coupling of the fastener in a variety of post-processing environments. Furthermore, the resin type material applied to the fastener is substantially resistant to the deposition of corrosion resistant or preventative materials.
Abstract:
An apparatus for the application of a fluoropolymer coating to the threads of an internally threaded fastener. The fastener has a body and a threaded bore extending to opposing ends of the body to define opposing first and second openings in the fastener. A conveyor moves the fastener along a path of travel with its threaded bore in a predetermined orientation. An obstruction member closes, the first opening, while a nozzle directs an air stream carrying entrained fluoropolymer powder through the second opening and into the threaded bore. The nozzle is stationary and is located at an axially displaced position relative to the second opening of the fastener and immediately adjacent the conveyor. A heating station heats the fluoropolymer powder to its melting temperature causing it to melt and fuse into a generally continuous film covering the fastener's threads.
Abstract:
A method of manufacturing a coated threaded fastener wherein the coating acts as a contaminant mask and the coating is applied as a dry powder mixture including a fluoropolymer resin, an inert filler and a coloring pigment.
Abstract:
A process and apparatus are provided for the application of a fluoropolymer coating to the threads of an internally threaded fastener. The fastener has a body and a threaded bore extending to opposing ends of the body to define opposing first and second openings in the fastener. The fastener is moved on a conveyor along a path of travel with its threaded bore in a predetermined orientation. As the fastener moves along its path of travel, the first opening is closed by means of an obstructing member, while an air stream carrying entrained fluoropolymer powder is directed from a nozzle through the second opening and into the threaded bore. The nozzle is stationary and is located at an axially displaced position relative to the second opening of the fastener and immediately adjacent the conveyor. Preferably, the nozzle includes a diffuser which directs the air stream and entrained fluoropolymer powder into the fastener bore in a diverging pattern. After the fluoropolymer powder is deposited onto the threads of the fastener, the conveyor moves the fastener through a heating station where the fluoropolymer powder is raised to its melting temperature causing it to melt and fuse into a generally continuous film covering the fastener's threads.
Abstract:
An apparatus for coating an internally threaded fastener includes a support having a support aperture in axial alignment with an aperture in the fastener, a nozzle for applying a coating onto the internal threads located on the fastener aperture, means for reciprocally moving the nozzle through said support aperture and into said fastener aperture to align with the fastener threads, and means for maintaining the spray head in a stationary position within the fastener aperture while said reciprocally moving means continues through its reciprocal cycle.
Abstract:
A method and apparatus for coating a fastener, particularly a fastener with a head portion and shank portion, with a coating material is provided. The invention includes the steps of and apparatus for supporting the fasteners such that the fasteners are positioned for coating. The fasteners are conveyed such that the fasteners are moved through a plurality of operating stations and pass through a heating station where the shank portions of the fasteners are heated. Subsequently, at a material applying station, a coating material is applied to the heated shank portions. A preferred embodiment of the method and apparatus of the present invention includes supporting the fasteners on their head portions with the shank portions projecting upward, conveying the fasteners with their shank portions projecting upward for processing, heating the shank portion to a temperature above the melting point of the applied material and applying the material to the heated shank portion to form a coating thereon.