Fastening system for benches or seats has screw with conical surface on underside of head engaging countersunk surfaces on gripping jaws to push them apart to grip wooden laths held in frame

摘要

A pair of laths is held in a U-shaped frame (1) with a threaded bore (2) at the bottom of the U-shape. A centrally-placed screw (7) has a threaded lower end which engages in the bore. The head of the screw has a conical undersurface (6) and a flat top surface with a hexagonal blind bore which accommodates an Allen (RTM) key. The head of the screw engages with chamfered surfaces (4) in clamping jaws (3) which are pushed outwards so that their outer ribbed surfaces (5) engage in the sides of the wooden laths.