GB544603A - Countersinking machine - Google Patents

Abstract

544,603. Dimpling. CHICAGO PNEUMATIC TOOL CO. May 12, 1941, No. 6116. Convention date, Sept. 10, 1940. [Class 83 (iv)] Thin metal sheets to be flush riveted have the sheets countersunk by a machine operated die and mandrel. The countersunk die 29 is formed in the end of the tube 24 extending from a boss 23 on a front cylinder cover 15. Spacing rings 18, 19, an intermediate partition 17 and a rear cover 16 all held together by bolts 19 constitute two fluid pressure cylinders C1 C2 admission and exhaust of fluid being controlled by a valve 48 operated by a hand lever 49. The piston 33 is normally held in the position shown in Fig. 1 by a spring 36 and is carried by a tube 32 the foreward end of which acts as a bevel closing ring for the split end of the piston rod 26 of the, piston 25 normally held in position shown by a smaller piston 38 always open to pressure supply at 22. The split end 26 tapped to receive an abutment screw 64 adjustable to set the mandrel 28 according to the thickness of the sheets. The mandrel is inserted from the opposite side of the work and the valve is moved to cause the piston 33 to move and close the end of the rod 26 to grip the mandrel by its threaded portion, after which the valve is moved further to admit pressure to both cylinders moving the mandrel to the position shown in Fig. 8 to effect the countersink. The valve 48 has a hollow interior ported at 55, 56 and 57 and is normally held by a spring 53 in the position shown in Fig. 3 in which the passages 44, 45 leading to the cylinders C1 and C2 respectively are open to exhaust through the interior of the valve and the ports 55. The valve seats at 52 on the lower edge of the casing 51 and pressure is supplied to the space 46 by a passage 47. As the valve is depressed a piston 63 prevents passage of fluid until the ports 55 are closed by the casing. With the valve in the half open position fluid passes to the passage 44 through the port 59 but the port 58 connected with the passage 45 is closed by the wall of the valve. In the fully open position fluid passes into the valve through the ports 56, 57 and passes to the port 58 by the ports 55.