River bank anti-erosion cladding slab fixing - has nail which enters hole from below for barbed shaft to be engaged by driven wedge sleeve with inner barbs

摘要

The fastener has a large flat circular head(18) on a pointed shaft(15) with circumferential saw-tooth section ribs(16) at regular intervals, being used with an internally ribbed sleeve(21) to fix a perforated river bank cladding slab on a sheet(12). The sleeve projects from an integral part conical cup(20) which matches the profile of a slab perforation(13), being driven onto the shaft to wedge in place. The fastener may be passed through the sheet from below, the head being concave to clamp elastically on the soffit of the slab. The head and the shaft may be separate pieces which are joined by elastic interlocking. An alternative design uses a shaft with an enlarged conical head and a stepped conical point, being driven into a sleeved washer below.