Bolt for supporting false ceilings - is retained by wedging effect of sliding key pressed in by spring

摘要

The bolt (1) has a flat surface (3) parallel to its axis which runs into an inclined surface (2). A taper key (4) which matches the flat surfaces (2) and (3) is attached to the bolt by a plastic ring (7). A coil spring (5) fits around the shank of the bolt and between stops (13) and a small plate with a slotted hole mounted on the bolt. The spring is compressed by pressing in the plate and this allows the key (4) to lie flat against the surface (3). The bolt is then inserted in the hole and the spring suddenly released so that the key (4) is driven between the bolt and hole and wedges the bolt firmly in place.