Self anchoring plate head bolt - has quarter turn to lock head in apertured hollow T section rail and opposed neck flats engaging slot sides

摘要

The plate head bolt may be used to make fixings in building construction. The head (21) is inserted in a slotted and flanged rectangular hollow section rail (1) where a quarter turn rotation effects a lock against further rotation. A nut may be wound on, to fix cladding and the reverse unseating rotation cannot be effected unless preceeded by an axial bolt penetration. The neck of the bolt shank (23) has opposed tangential shoulders (41) which engages the internal faces (15) of the slot defining flanges, and the head (21) thickness (T) is less than the corresponding internal rail dimension (9) by a distance exceeding the axial shoulders depth (D). The head is inserted fully, rotated a quarter turn, and retracted axially until the shoulders (41) engage. In addn. the head (21) may have a parallelogram plan shape with acute angles of some 70 deg.