Arrangement for mounting automotive glass to liftplate

In a window mounting arrangement for an automotive vehicle, a glass sheet having a circular hole spaced inwardly from a marginal edge thereof, a metallic liftplate having one surface spaced opposite one surface of said glass sheet, a spacer bushing formed of polymeric material located between said liftplate one surface and said glass sheet one surface, an aperture in said liftplate in registry with said glass sheet hole, a retainer assembly positioned on the other surface of said glass sheet, said retainer assembly comprising a plastic capped retainer member and a metal T-nut member, said capped member formed with a hollow stem portion of predetermined outer diameter and axial length, sad stem portion defining first and second extremities, a planar radially extending cap portion extending from said stem portion first extremity, said stem portion telescopically associated within said glass sheet hole such that with said retainer cap portion in flush contact with the other surface of said glass sheet said stem portion is radially spaced slightly inwardly from said glass sheet hole and its second extremity is spaced a slight axial distance from said liftplate inner surface, said T-nut member formed with a hollow tubular portion of predetermined outer diameter and axial length defining first and second extremities, said tubular portion having a right-hand internal thread providing clockwise tightening rotation, a generally planar radially extending anchoring head portion extending from said tubular portion first extremity, said head portion having an intermediate flexible portion spaced axially from said retainer cap portion, said plastic retainer cap portion having a peripheral reverse bend hem engaging the periphery of said T-nut head portion such that said capped retainer and T-nut members are locked against relative movement, the improvement wherein:

• said retainer hollow stem portion formed with an external left-hand thread, said spacer bushing including a central portion and an outer rim portion interconnected by an intermediate relatively thin flex ring of predetermined thickness, and wherein said central portion having a predetermined thickness less than said rim portion and greater than said flexing, said central portion formed with a through bore having an internal left-hand thread mating with said stem external left-hand thread, whereby upon initial tightening of said spacer bushing on said retainer stem portion said spacer bushing outer rim portion is positioned in flush abutment with said glass sheet one surface;
• a bolt having a shank extending through said liftplate aperture and telescopically associated within said stem bore, said shank formed with a right hand thread threadably engaging said T-nut tubular portion internal thread, whereby upon tightening of said bolt in a clockwise rotational direction said spacer bushing outer rim portion is further tightened in a counter-clockwise rotational direction against its associated glass sheet one surface and liftplate one surface allowing said retainer assembly to apply a predetermined clamp load wherein said spacer bushing flex ring is deflected causing said rim portion to be clamped into flush bearing contact with said glass sheet one surface and said lift plate one surface in a non-slipping manner;
• and whereby upon said bolt being further tightened said glass sheet one surface being clamped into bearing contact with said spacer bushing rim portion in an area removed from the edge of said glass sheet hole whereby the clamp load on said glass sheet is removed from the edge of said glass sheet hole thereby obviating glass sheet breakage.