GB870900A - An explosive power assisted, hammer driven tool - Google Patents

Abstract

870,900. Cartridge-operated tools for driving fasteners. ADOLPH, J. L. Nov. 23, 1959 [Nov. 27, 1958; March 26, 1959; Aug. 28, 1959], No. 39622/59. Class 119. A cartridgeoperated tool for driving fasteners into material comprises a body 1, Fig. 3, in which are slidably mounted a cartridge plunger 8 and a drive plunger 9, the outwardly directed end of the plunger 8 terminating in a head 22 adapted to be struck by a hammer for driving the plunger 8 towards the drive plunger 9, the inwardly directed end of the plunger 8 having an axial hole 24 for reception of a cartridge 25. The outward movement of the drive plunger 9 is limited by engagement of an annular surface 14 on the plunger with an abutment surface 15 on the body, the inner end of the plunger 9 being adapted to fire the cartridge upon sufficient percussion therewith while the outer end supports the fastener 71 in a recess 72. The arrangement is such that the cartridge plunger 8, when hammer driven with sufficient force, causes the cartridge to come into percussive contact with the drive plunger 9 thereby detonating the cartridge and driving the plunger 9 for the extent of its limited outward movement whereby the fastener is forced into the material a distance substantially corresponding to this movement. As shown in Fig. 3, the cartridge 25 protrudes from the hole 24 to provide a cushioning effect for the impact of the plungers but in a modification, Fig. 6 (not shown), the cartridge 25<SP>1</SP> is fully inserted into the hole 24 and a spring 66 is provided between the plungers. The stem 20, Fig. 3, of the plunger 8 passes through and is slidable in a breech block 21 which is removable from the body 1 together with the plunger 8 for loading and unloading. For this purpose two radial lugs on the breech block co-operate with inwardly extending abutments on the body 1, the insertion of the breech block and plunger assembly being effected by the lugs passing between the abutments and then turning the breech block to locate the lugs behind the abutments. Various safety devices are provided which while permitting outward movement of the plunger 8, prevent inward movement except when released by forward movement of a sleeve 2 against spring action. In operation after loading and release of the safety devices, the cartridge plunger 8 is slowly traversed by hand along the bore 7 towards the drive plunger 9, if necessary pushing it for the full length of the inward travel. The fastener 71 is then inserted in the plunger 9 and the tool pressed towards the workpiece thereby pushing the fastener and plungers inwardly to the position shown in Fig. 4. The sleeve 2 is then stressed forwardly to release the safety devices and the head 22 then struck with a hammer to fire the cartridge and drive the fastener.