Abstract: An apparatus for holding an insertion tube of a borescope centered within a passage along which the borescope travels, that includes a pair of opposed collar assemblies slidably mounted upon the insertion tube of the borescope, with each collar assembly including a cylindrical body section and an annular retaining ring, being removably mounted in face-to-face contact with one end face of the body section, and each retaining ring having a rear end face in contact with one body section and a front end face facing that of the retaining ring on the opposing collar assembly, and each retaining ring further including a series of circumferentially spaced rotor seats each having a longitudinally disposed slot passing through the outer wall of the ring, and a plurality of elongated wire spring members with each end fitting in a rotor seat, thus joining the opposing collar assemblies, where one of the collar assemblies is held in a stationary position adjacent to the distal viewing end of the borescope while the other

Abstract: An abrasion-resistant coated plastic lens element and a method for coating the element with an abrasion-resistant coating includes forming a coating on a face of a mold that is substantially cured and adherable to lens-forming material. The coating composition consists of reactants, approximately 70% to 95% of which have at least triacrylate functionality and approximately 5% to 30% of which have diacrylate functionality, a photoinitiator, a polymerization inhibitor reactive with oxygen, and a silane adhesion promoter and an acid to activate the silane adhesion promoter. The coating is applied to the face of the mold to form a substantially uniform coating and is then subjected to ultraviolet light in an ambient oxygen-containing environment such that a hard abrasion-resistant coating is formed on the mold. The mold is then filled with a lens-forming composition which is reactive with acrylate groups of the coating at a coating/lens interface.