Panel insert and method of installation

Claim 1

An insert assembly for installation in a lightweight panel such as a panel including a honeycomb core and skin sheets secured to the opposed sides thereof and having an insert assembly accommodating aperture extending through one of said skin sheets and continuing through the core to the opposite skin sheet, said insert assembly including an insert member having a base section, said base section having a first substantially flat surface for seating engagement with said skin sheet and a second substantially flat surface facing in a direction opposite to said first surface, and a threaded section of reduced width extending axially from said second, substantially flat surface the exterior surface of said threaded section being disposed perpendicular to saId second surface, said insert assembly also including a member surrounding at least a portion of the periphery of said threaded section, said member being formed of a thermoplastic material that will become viscous and flow when heated and will solidify when cooled, means for applying heat to said member and for controlling flow of said thermoplastic material when in the viscous state, said means including a heat conductive collar superimposing a portion of said thermoplastic member, said heat conductive collar comprising, an apertured end wall portion overlying an end of said thermoplastic member and having inner and outer marginal edges, an inner wall portion extending axially from the inner marginal edge of said end wall and surrounding said threaded section and disposed intermediate said threaded section and said thermoplastic member, and an outer wall portion overlying a segment of the external periphery of said member and extend axially from said end wall portion from a location proximate the outer marginal edge thereof, said inner wall portion having a length greater than that of said outer wall portion; and said thermoplastic member, in the unassembled condition, having an axial extent such that upon seating of said base section on a skin sheet, said end wall section will be disposed exteriorly of said panel, while said inner wall portion is spaced axially from said second, substantially flat surface of said base section, and the end of said exterior wall portion will be disposed at a location that would place it at or below the upper surface of the apertured skin sheet in which the insert is to be disposed; such that upon the application of heat to said collar, said thermoplastic member will become viscous permitting said collar to move inwardly until said inner wall portion engages said second substantially flat surface which engagement precludes further inward movement of said collar, and assures that the end of said outer wall portion is spaced from said second substantially flat surface, the initial positioning of said outer wall portion assuring that said viscous material does not flow exteriorly of the panel while the final position of said outer wall portion assures that said viscous material will flow outwardly of said insert assembly whereby upon cooling and solidification of said thermoplastic material, an assembled relation between said insert assembly and a panel may be attained.