GB1288897A - - Google Patents

Abstract

1288897 Explosively-actuated fastener-driving tools OLIN CORP 19 April 1971 [12 June 1970] 25017/71 Heading B4C A fastener driving tool comprises a housing 2, Fig. 1, a barrel 4 and an interchangeable muzzle bushing 6. The firing chamber comprises movable wall portions to contain a caseless explosive pellet. Magazine.-A magazine 22, Fig. 4, of caseless pellets 24 is mounted in a magazine slot 18 in the handle 8, Figs. 2 and 4. The pellets are slid out of the magazine by a pellet follower 20 which comprises a main body portion 30 having a raised hump 32 which projects outwardly through the slot, and permits manual adjustment. A pellet pusher 40 is mounted on a pin 38 connected to the follower body. The follower is hooked over a shoulder 48, Fig. 5, to permit reloading. Firing assembly.-A bolt 50, Fig. 5, and firing pin 54 are mounted in the housing 2. The bolt includes gas-sealing grooves 60. The pellet is surrounded by a gas-tight shroud (a countersink 62) when the tool is cocked. The firing chamber is formed by shoulders 64 in the countersink 62 and prongs 58 on the bolt 50. The firing pin co-operates with an anvil member 68 which has gas-escape passages 70. A piston 72 has a piston stem 76 to drive a fastener 82. The piston is returned by a spring 88 and pawl 16. Power adjustment.-Rotation of a power adjustment drum (graduated if necessary) adjusts stops which limit the extent of forward movement of the barrel 4 used to return the piston from its "fired" to its "firing" position. This in turn determines the distance 116, Fig. 5, between the rear face of the piston head 74 and the forward face of the anvil, and thus the size of the firing chamber and the power of the tool. Cocking.-When the tool is pushed against a surface 84 the barrel 4 moves rearwardly against a slide web 120 so that a notch 138, Fig. 6, pushes the firing pin 54 rearwards to its cocked position. When the rear face of the barrel 4 contacts the bolt 50, a lug 136 is aligned with a spring plate 146 and when the trigger 140 is pulled a sear 126 pivots clockwise and disengages the notch 138 from the firing pin 54. The pin is then urged forward by its spring 56. Cocking is thus only achieved by full push-down against a working surface and can only be fired at full push-down. The cocking mechanism prevents free firing, stab firing and drop firing. Pellet feed.-The pellet 24 is fed by a head 152, Fig. 11, in a slidable plunger rod 148 from a passage 44, Fig. 5, and is pivoted through 90 degrees during its transfer from the magazine to the firing chamber, by co-operation of a stud 176, Fig. 5, in a slot 166 (Fig. 11) in a cam block 162. The chamber is opened for loading by actuation of a handle 180 and pushing upwards of the handle causes the 90 degree rotation.