Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B33/00—Features common to bolt and nut
  • F16B33/06—Surface treatment of parts furnished with screw-thread, e.g. for preventing seizure or fretting
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B37/00—Nuts or like thread-engaging members
  • F16B37/04—Devices for fastening nuts to surfaces, e.g. sheets, plates
  • F16B37/044—Nut cages
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B37/00—Nuts or like thread-engaging members
  • F16B37/04—Devices for fastening nuts to surfaces, e.g. sheets, plates
  • F16B37/06—Devices for fastening nuts to surfaces, e.g. sheets, plates by means of welding or riveting
  • F16B37/061—Devices for fastening nuts to surfaces, e.g. sheets, plates by means of welding or riveting by means of welding

Definitions

• the present invention relates to an encaged threaded fastener, and, more particularly, to an encaged fastener which minimizes problems of adhesion of the threaded fastener to the cage by application of paint or other coatings.
• the frames Prior to coupling of the components to the frame, however, the frames typically are painted or coated using e-coat processes. To date, the step of painting the frame often will cause the fastener to adhere to the cage. This prevents the fastener from being adjustable within the cage and, therefore, causes tolerance problems in the final assembly of the product. To prevent the tolerance problems, post-process inspection after painting is required to ensure that the fasteners are not adhered to the cage. Should the fastener be adhered to the cage by coating, post-process rework must be conducted to free the fastener.
• this invention provides a cage nut fastener which is weldable to a substructure that overcomes the problems and disadvantages of the cage nuts of the prior art.
• the invention includes a threaded fastener; a fastener cage capable of fastening the fastener to a substructure, the cage having a coating which inhibits coatings from sticking to the cage.
• FIG. 1 is a perspective view of the cage nut fastener in its unassembled condition
• FIG. 2 is a perspective view of the cage nut of the present invention in its assembled configuration
• FIG. 3 is a cross-section of the cage nut in FIG. 2 showing the relationship of the coating with respect to the fastener and the cage.
• a cage nut fastener shown generally at 8 has a body 16 coupled to a planar base 12.
• the body 16 and planar base 12 define a threaded through bore 14.
• Planar base 12 has an upper base surface 18 and lower base surface 20.
• the cage nut assembly 8 further has a cage 22 which is generally disposed about the planar base 12.
• the cage 22 has a cage upper surface 34 and cage lower surface 32. Additionally, the cage 22 defines two pair of flanges 28.
• the flanges 28 define cutouts 26 which generally correspond to the shape of the body 16.
• the flange elements 28 are folded to enclose the planar base 12 of the body 16.
• the flanges 28 are positioned so as to restrict the movement away from the cage 22 of the body 16.
• the cutouts 26 are positioned so as to restrict the planar movement of the body 16 within the assembly.
• the cage 22 is configured so the body 16 has a limited range of movement. As can be seen in FIGS. 2 and 3, the cage allows slight movement away from the cage upper surface 34 as well as allowing planar movement generally parallel to the cage upper surface 34. This planar movement is generally restricted and defined by the space between the cutouts and the body 16.
• the cage 22 has a coating layer 35 disposed on a surface which directly faces the hexagonal body 16 or planar base 12.
• This coating provides a surface that has a low wetability, and preferably has a lower wetability than the body 16. This significantly reduces the amount of wetting of any coatings subsequently sprayed onto the as coated cage 22.
• the coating 35 be applied at a weight of 2 to 9 mg/sq. ft. and preferably at 3 to 5 mg/sq. ft. and have a dynamic coefficient of friction of less than about 0.3 and, more preferably, less than 0.2.
• the coating can be selected from the group of hexavalent and trivalent chromium with phosphoric acid passivation treatment (available as Permatreat 2510 from Betz Laboratories), a mixture including paraffin wax (122-130°F melting point) and a blend of a non-ionic surfactant (HLB 4.7) and nonionic surfactant (HLB 14.9) available as Trisco Tex CN from Scholler Inc.
• the coating can be a fluoropolymer such as PTEF, an e-coat layer, or DC-9870 from BetzDearborn.
• the coating 35 functions to prevent any additional e-coating or paint from sticking onto the cage 22.
• the coating 35 will stick onto the body 16, planar base 12, and threaded through bore 14.
• the coating 35 provides a significant resistance to adhesion of the paint to the surface of the coating 35. This prevents a coating bridge from forming and allows the body 16 and planar base 12 to float freely within the cage 22.
• the coating can be adhered to just the upper surface 34 of the cage 22. Additionally, the coating can cover the cage lower surface 32 and the surfaces of the cutouts 26.
• the coated cage of the assembly of the present invention minimizes problems of paint adhesion by providing a surface which has a very low coefficient of friction, thus allowing drainage of the paint and minimizing contact between the body 16 and the cage 22. These improvements significantly increase manufacturing speeds by reducing the amount of post- painting rework.
• the cage and/or nut can be coated with non-stick coatings.
• the cage or nut can be coated with an epoxy coating containing between about 5% to about 30% and preferably between 10% and 20% PTFE.
• the PTFE can be in a powder form.
• An example of this material is E-Coat Block produced by Environmental Protective Coatings of Ohio.
• the body 16, prior to forming of the cage nut assembly can be coated with a mixture of about 10% to about 20% and preferably between about 12% and about 18% and most preferably about 15% volatile solvents; and about 15% to about 35% and preferably between about 20% and about 30% and preferably about 26% epoxy; and between about 40% and about 60% and preferably about 26% to about 50% and most preferably between about 48% water and about 5% to about 15% and preferably about 9% ash.
• the coating contains small amounts of amine material to facilitate cross-linking of the epoxy.
• An example of an epoxy that can be used is Bisphenol epoxy.
• the ash can take the form of Ti or Fe materials.
• the epoxy of the coating materials is held in suspension within the water and volatile solvents. It is believed the coating according to the present invention has a pigment to binder ratio below a point so as to form a resin-rich surface coating. This resin-rich coating is glossy so as to inhibit any adhesion of the e-coat to the nut. Further, the resin-rich coating is weak and will fracture should a small e-coat bridge form.
• the body component 16 and planar base 12 having a coating of cross-linked epoxy, and ash.
• the body 16 and base 12 can be coated with a material having between 50% and 90% epoxy and between 15% and 30% ash.
• the body 16 and base 12 can be coated with a layer having 75% epoxy, and 25% ash. This particular combination has been found to allow the coating on the nut to survive standard manufacturing environments prior to e-coat applications. It is further thought that this percentage of ash material allows for the proper coefficient of expansion of the coating to allow proper adhesion of the coating to the nut.
• either the cage or the fastener can be coated with either Permatreat 2550, which contains trivalent chrome or Betz DC- 1578A. It is envisioned that the cage 22 and the body 16 can be coated with any of the aforementioned materials. Additionally, the body 16 can be coated with differing materials. As an example, the body 16 can be coated with E- COAT BLOCK while the cage 22 can be coated with Permatreat 2550. As the cage must be welded, it is preferable that the cage be conductive.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Chemical Treatment Of Metals (AREA)

Applications Claiming Priority (7)

Publications (1)

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• 2002
  • 2002-10-30 WO PCT/US2002/034608 patent/WO2003042557A1/en not_active Application Discontinuation
  • 2002-10-30 EP EP02773935A patent/EP1440244A1/de not_active Withdrawn
  • 2002-10-30 JP JP2003544354A patent/JP2005509807A/ja active Pending

Non-Patent Citations (1)

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