Staked fastener

581,786. Bolting; spiked plates. RADIO CORPORATION OF AMERICA. Dec. 9, 1943, No. 20640. Convention date, Dec. in, 1942. [Classes 89 (i) and 89 (ii)] [Also in Group XXII] Bosses are secured to parts of plate-like form by means of inwardly tapering circular projections in combination with prongs for preventing rotation of the projections in the holes in the plates. The fastening is applicable to securing nuts,.bolts, screws, electric terminals, studs, &c. to a chassis, panel, or other base, particularly one of soft metal such as aluminium. The boss is of harder metal than the base. A square nut 2, Fig. 1, to be anchored to a plate 5, Fig. 3 has a central projection 6 tapering inwards at 7, and pyramidal prongs 1 at the corners with faces 9 at an angle to the surface 8 so that when the nut is pressed into the plate the prongs are caused to enter the plate in outwardly splayed form. The nut is located so that the projection 6 enters the hole in the plate, by a pin 15 in the lower die 14. After pressing, the work is reversed on the same or a similar die 14, Fig. 4 and the metal of the base is caulked by a bevelled ring 18 on a die 19 to cause flow to fill the space caused by the undercut 17. A separate caulking operation may be avoided by forming an annular projection 21, Fig. 7 on the nut so that caulking is effected thereby during the pressing-in of the prongs 1. For use in thicker plates the projection 6 is made cylindrical for part of its length.