Pin for driving into stone or metal building elements

Claim 1

A PIN ADAPTED TO BE DRIVEN INTO A STRUCTURAL PART BY MEANS OF A FIRING TOOL, SAID PIN INCLUDING AN ELONGATED STEM PORTION HAVING A PENETRATING POINT AT ONE END THEREOF AND A RADIALLY ENLARGED HEAD PORTION AT ITS OPPOSITE END, THE SAID PIN BEING CONNECTED TO A PLASTIC DISC OF RESILIENTLY YIELDABLE PLASTIC MATERIAL, WHICH IS INTENDED TO GUIDE THE PIN IN THE BARREL OF THE FIRING APPARATUS, CHARACTERISED IN THAT THE DISC OF RESILIENT MATERIAL IS ASSOCIATED WITH A RELATIVELY NON-YIELDABLE METALLIC DISC SO THAT A PORTION OF THE RESILIENTLY YIELDABLE DISC BEARS AGAINST THE NON-YIELDABLE DISC, AND THE EDGE OF THE YIELDABLE DISC PROJECTS RADIALLY BEYOND THE OUTER EDGE OF THE NON-YIELDABLE DISC, BOTH OF SAID DISCS BEING FRICTION FIT ON SAID STEM PORTION BY CENTRAL APERTURES AND BEING POSITIONED THEREON ADJACENT SAID PENETRATING POINT WITH SAID RESILIENTLY YIELDABLE PLASTIC DISC BEING LOCATED AXIALLY CLOSER TO SAID POINT THAN IS SAID NON-YIELDABLE METALLIC DISC, WHEREBY SAID RESILIENTLY YIELDABLE PLASTIC DISC IS ADAPTED TO PROVIDE A SEALING MEANS AND SAID NON-YIELDABLE METALLIC DISC IS ADAPTED TO LIMIT PENETRATION OF THE PIN BY ENGAGING SAID ENLARGED HEAD PORTION WHEN THE PIN IS DRIVEN INTO SAID STRUCTURAL PART.