Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R4/00—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation
  • H01R4/28—Clamped connections, spring connections
  • H01R4/30—Clamped connections, spring connections utilising a screw or nut clamping member
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R4/00—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation
  • H01R4/58—Electrically-conductive connections between two or more conductive members in direct contact, i.e. touching one another; Means for effecting or maintaining such contact; Electrically-conductive connections having two or more spaced connecting locations for conductors and using contact members penetrating insulation characterised by the form or material of the contacting members
  • H01R4/64—Connections between or with conductive parts having primarily a non-electric function, e.g. frame, casing, rail
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R9/00—Structural associations of a plurality of mutually-insulated electrical connecting elements, e.g. terminal strips or terminal blocks; Terminals or binding posts mounted upon a base or in a case; Bases therefor
  • H01R9/16—Fastening of connecting parts to base or case; Insulating connecting parts from base or case

Definitions

• This invention relates to fastener arrangements for composite structures and more particularly to methods and associated fastener arrangements for establishing electrical continuity between fasteners and composite structures.
• FIGURE 1 is illustrative of prior art fastener connection installed in a composite panel structure
• FIGURE 2 is a sectional view illustrative of an apparatus and method in accordance with a preferred embodiment of the present invention for providing increased conductivity between fastener and composite structure;
• FIGURE 3 is a view of the assembly of Figure 2 blown apart to show the manner of assembly of the fastener arrangement of Figure 2;
• FIGURE 4 is an expanded and enlarged view of the crosssection of the present fastener assembly shown in Figure 2 deemed helpful in understanding the manner in which increased conductivity is achieved,
• the stud assembly indicated generally by the numeral 10 includes a bolt having a head portion 14 and a shank portion 16 passing through the composite panel structure 12, The usual washers and locking nut 18 complete the assembly of grounding stud 10 to composite panel structure 12.
• countersunk insert device 22 comprises a generally tubular shaped body of corrosion resistant stainless steel or titanium having two continuous integral coaxial portions 30 and 32 disposed about the central axis 40 of the fastener 10 shown in place in Figure 4.
• Countersunk insert device 22, being of tubular shape about coaxial hole 31 comprises an upper frustro conical shaped portion 30 and a lower cylindrically shaped flange-like portion 32.
• Graphite epoxy structures such as panel member 12 shown in Figure 4 have much better conductivity in a longitudinal direction (the current flow stays in the plies), than in the transverse direction, such as in the direction 40 along the central axis of a fastener inserted in the graphite epoxy structure.
• the reason for this is that the currents must cross, the epoxy boundary between plies and run transverse to the graphite filaments which lie along the longitudinal direction 42 of current flow within the graphite epoxy structure 12.
• This difference in conductivity can be as high as 200:1.
• the countersunk insert devices 20 and 22 in accordance with a preferred embodiment of the present invention provide the increased conductivity between shank of a fastener, such as the grounding stud 20 shown in Figure 4, and the longitudinal fibers of the conductive structure running in the direction of current flow represented by the numerals 42 in Figure 4.
• edge-to-edge resistivity is approximately 200;1 for a graphite epoxy type composite structure 12.
• resistivity of graphite epoxy composite structures varies from 10 3 to 10 6 that of an equivalent aluminum sheet. Therefore, the optimum bonding and ground resistance for a fastener such as a ground stud 20 shown in Figure 4 in a composite panel structure 12 can be successfully realized by utilization of countersunk insert devices 20 and 22 which provide electrical contact between shaft portion 16 of a fastener and an increased number of the longitudinal fibers of the composite structure 12. This is due to the frustro conical shaped portion 30 of countersunk insert 22. Transverse conductivity is also improved between the faying surface of countersunk insert device 22 and the outer plies of composite structure 12.
• Countersunk insert device 20 is shaped identical to countersunk insert device 22 hereinbefore described, and is located in a complementary-shaped countersunk hole on the other side of composite structure 12,
• the hereinabove described embodiment of the present invention teaches a method and structures including the utilization of countersunk insert devices which, will achieve the maximum transfer of currents between the shanks of fastening deyices and transversely extending fibers in composite panel structures in which, fasteners are utilized.
• the longitudinal conductivity property of these advanced composites such as graphite epoxy composites may be utilized in accordance with further embodiments of the invention by those skilled in the art, recognizing that the aforementioned countersunk insert devices may be utilized where, for example, fasteners such as self-locking nuts, shear collars, fixed nut plates or floating nut plates are utilized.
• the present countersunk insert devices may be utilized on either side of a pair of composite panel members being secured together by standard types of fasteners having shank portions 16 which must be connected to longitudinally extending fibers in the composite panel members utilizing the increase conductivity teachings of the preferred embodiment of the present invention.

Landscapes

• Connection Of Plates (AREA)
• Laminated Bodies (AREA)
• Moulding By Coating Moulds (AREA)

Applications Claiming Priority (1)

Publications (3)

Family

ID=22161454

Family Applications (1)

Country Status (3)

Cited By (1)

Families Citing this family (1)

Citations (7)

Family Cites Families (2)

• 1981
  • 1981-09-30 WO PCT/US1981/001318 patent/WO1983001345A1/en active IP Right Grant
  • 1981-09-30 EP EP82900055A patent/EP0089953B1/de not_active Expired
  • 1981-09-30 DE DE8282900055T patent/DE3176798D1/de not_active Expired

Patent Citations (7)

Non-Patent Citations (1)

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