GB830447A - Pull gun - Google Patents

Abstract

830,447. Blind riveting. HUCK MANUFACTURING CO. Oct. 29, 1956 [Feb. 3, 1956], No. 32893/56. Class 83 (4). [Also in Group XXV] A fluid-actuated pull gun comprises a body defining a bore for a piston 46, a piston-rod 44, a second piston 64 in a second bore 62, the first bore being adapted to have fluid circuits successively established at opposite ends of the first piston to drive the first piston in opposite directions, the second piston being actuated in response to a predetermined fluid pressure in the first bore by means responsive to the fluid pressure in the first bore for establishing fluid circuits acting on the second piston, a first valve means 20 for establishing the fluid circuits to the first bore, the means responsive to the fluid pressure in the first bore establishing a fluid circuit between the second bore for the seccnd piston and a fluid reservoir 70, and a third bore defined by a housing 7, a third piston 24 being mounted in the third bore, the first valve means being selectively operable to actuate the third piston to force fluid into the first bore. The slide valve 20, actuated manually by a trigger 14 admits compressed air through a port 30 to drive pistons 24 and 28 to the left, Fig. 1, thus displacing fluid, e.g. oil, from a cylinder 11 into a cylinder 48 to drive the piston 46 upwards. Piston 46 carries the hollow piston-rod 44 which has its longitudinal axis offset so that the distance between the axis and the end 49 of the gun is a minimum. A collet 40 carried on the piston-rod is adapted to grip the shank 84 of a rivet pin 81 and pull it through the rivet sleeve 85 deforming the latter against the reaction of an outer anvil 56 which is mounted on a tubular member 58 bearing against the piston 64 in the secondary cylinder 62. At a pressure in main cylinder 48 predetermined by the adjustment of a spring valve 68 trapped fluid is displaced from the cylinder 62 into the reservoir 70, Fig. 3, permitting the anvil 56 to retract, Fig. 8, transferring the pull-reaction to a fixed inner anvil 54 so that on continued movement of piston 46 frangible locking portions 87 of the rivet are deformed as shown in Fig. 5B. Further movement of piston 46 breaks the rivet shank at 95, the free portion being ejected. Release of the trigger 14 admits air to return pistons 24 and 46 and also recharges the cylinder 62 with fluid, thus advancing the anvil 56 again. Specification 629,098 is referred to.