GB592462A - Automatic centre punches, chisels, hammers and like impact tools - Google Patents

Abstract

592,462. Engraving. SOC. A.R.L. MERMET & VIRTHNER. May 7, 1945, No. 11625. Convention date, Feb. 26, 1943. [Class 100 (ii)] [Also in Group XXIII] An automatic release spring striker centre punch, chisel, hammer, letter punch, figure punch &c. comprises an arrangement of balls 23 located in recesses in a sleeve 2 of less thickness than the diameter of the balls and coacting with a retaining ring 18 such that during the loading of the spring 12 by pressure on the outer casing 1 the balls are backed up by the wall of the ring 18 so as to engage a groove 24 in the striker 11 thus holding up the striker but continued movement of the casing 1 causes an inner shoulder on the casing to depress ring 18 allowing the balls to enter a groove 25 in the ring and release the striker. The punch &c. 5 has end play in its holder so that it receives the full force of the blow which is adjustable by rotating the screw cap 13. The parts are restored to their normal position when pressure is removed from the casing by the loading spring 12 which lifts the casing until the flange 16 contacts the flange 15 on the striker whereupon casing and striker are further lifted together bv another spring 17 until pin 4 at the bottom of the casing reaches the top of its slot 3, the ring 18 being finally lifted by a third spring 19 to move the balls into locking engagement with the groove in the striker.