Patent GB-839930-A (GB)
Title: Explosively actuated driving tool
IPC: B25C1/12
Filed: 1958-04-09
Abstract: 839,930. Explosively actuated driving tools. MINE SAFETY APPLIANCES CO. April 9, 1958 [June 10, 1957], No. 11197/58. Class 119 An explosively operated firing tool is characterized by a rotatable plunger 4 normally slidably urged forward in a housing 3 and having a lengthwise passage 10 to one side of its axis that releasably houses a forwardly extending barrel 22 with an accessible cartridge chamber 29; also by a manually operable firing' pin 63 carried in the housing 3 from which the barrel is off-set in the loading position, but in alignment when the plunger is rotated and when the striker can. be re-. tracted by moving the housing forward relative to the plunger and the barrel. Figs. 4 and 6 show a sectional plan of the tool as seen from above, Fig. 4 showing the loading position and Fig. 6 the firing position with the barrel and plunger pushed back and the striker cocked. The housing is supported on a stock 2 shown partially in Fig. 4. The plunger is retained in the housing by a flanged coupling-ring 7 that is screwed into the front end of the housing. On one side of its axis the plunger carries a screwed sleeve 26 to which the barrel is interchangeably attached by a split spring-ring 27. On the other side, in the passage 10, it houses a plunger 13 which is normally retained by a spring forward from the rear end of the housing 3 and which is screwed to a ring 15 that is locked by grub-screws 20 to the. rear end of a tube 19 which can turn about the coupling ring 7. The cartridge chamber is made accessible for loading by a lateral opening 33 (Fig. 14,- not -shown) in the housing 3. Axial movement of the plunger 4 in the housing is prevented in the loading position by a cap screw 34 on the former engaging in an annular groove 35 in the latter. After the plunger has been rotated 180 degrees to the firing position, the screw 34 is aligned with a longitudinal slot 36 so that the plunger can be moved axially. The plunger and barrel are rotated by turning the tube 19 relative to the housing, movement in either direction being limited by a pair of stop pins 37 projecting into the groove 35 (Fig. 12, not shown). A breech-block in the form of a thick plate 40 is integral with a ring 41 that is screw threaded on to the outside of the plunger and is constrained to move lengthwise by a pin 43 in a longitudinal slot 42. When the barrel is rotated through 180 degrees from the loading to the firing position the breechblock is drawn forward towards the plunger to hold the cartridge securely in the chamber 29 and is retained by a ball and plunger which engages the ring 41. The ring 41 supports a rotatable ring 53 carrying a transverse bar 50 with a notch 51 that fits the cartridge rim and acts by moving backwards and forwards with the breech-block 40. The firing pin 63 is urged by a firing spring 66 towards the front end of a cylindrical bore in the rear end of the housing 3. When the tube 19 relative to the barrel, a retractor pin projecting back from the breech-block cocks the striker, which is then retained by a plunger 71 engaging behind the retractor pin 74. The pin 74, the trigger and the trigger mechanism that releases the striker for firing are illustrated in Figs. 7 and 14 (not shown). By rotating the ring 53 the bar 50 can be reversed to expose an alternative notch which will accommodate a cartridge of a different size that is used when barrels are interchanged. A muzzle guard shield 95 on a sleeve 96 as described in Specification 839,929 is rotatably mounted on the barrel.