GB651466A - Improvements in or relating to fastening devices of the self-locking nail type - Google Patents

Abstract

651,466. Nails. ELASTIC STOP NUT CORPORATION OF AMERICA. Aug. 1, 1947, No. 20936. Convention date, Jan, 26, 1944. [Class 89(ii)] [Also in Group XXII] Relates to sheet metal hails of the type in which one part is arrested by a head before another part is driven completely home; the parts being so connected that' the latter part is caused to deflect laterally. In one form a blank is split at 12 from the head end as far as 12a, one member 16 is stiffened by longitudinal ribs 26 and 30 and weakened by a transverse rib 28, and the other member has a projection 22 that slides in the rib 26, a notch 20, lug 18, and on offset 32 just below the rib 28. The blank is folded so that the projection 22 is received in the groove formed by the rib 26 and the lug 18 bent to retain the two parts in sliding engagement. The end 10 is bent over at the dotted line a diamond - shaped recess 24 forming a strengthening flllet. The member 16 is curved at the top to provide a driving edge 38. When the head 34, Fig. 2, is arrested, further driving of the edge 38 causes the part 16 to bend at 28 so that the point extends laterally into the material as shown. The head 34 is preferably bent to an acute angle with the shank so that it lies flat in the clinched position. In a modification the edge 38 also has a bent over portion. A blank for a form that has two points that diverge laterally in opposite directions is split from the point at 68, Fig. 7, as far as a hole 66, points of weakness are formed by holes 64 from which slits 54 extend to the head end. The side parts are folded about the lines 80, on opposite sides of the centre part that is stiffened by ribs 88. In a further form a centre member is arrested by its head that is slotted to guide side members that collapse and diverge laterally and outwards. In another form, slit at 152, 154, Fig. 17, the outer parts are bent at the line 158 to form arresting heads extending to one side and the end 172 is bent to the other side to form the driving-head. This is reduced in width so that when the nail is fully driven the arresting heads spring in, over the shoulders formed, preventing withdrawal. Fig. 18 shows a blank in which lugs 212 from the arresting head and the driving-head extends through the slot 210. In a final form the driving end has a hollow domed head attached and this snaps over the arresting head when the nail is driven home. This form is preferably made from brass and is used for securing upholstery.