GB406523A - Improvements in blasting cartridges - Google Patents

Abstract

406,523. Blasting-cartridges; tampings. SAFETY MINING CO., 307, North Michigan Avenue, Chicago, U.S.A. May 19, 1933, No. 14568. Convention date, May 19, 1932. [Class 9 (i).] A blasting-cartridge containing a charge of liquefied or compressed gas is provided with a closure which is mechanically removed or ruptured or weakened so as to yield to the gas pressure. The mechanical means may be operated from a distance. In Fig. 1, the cartridge 1 is shown closed by a disc 3 supported by a toggle 5, 6 which can be broken to the dotten position by a pull on a cable 9. In Fig. 2, the closing disc 3 is shown supported by a second disc 10, which can be broken by gas pressure admitted thereto by a valve 13 operated by a cable 15. In the form shown in Fig. 5, the operation of the cartridge 16 is brought about by a gun or power hammer 20, which may contain a spring plunger held cocked by a trigger releasable by a pull on a cable, or may contain a pneumatic plunger held cocked by a trigger released by a pressure gauge when sufficient pressure, say 150 to 175 lbs. per sq. in., is admitted behind the plunger. This hammer device is clamped in the bore-hole by a rubber sleeve or fingers 33 expanded by a screw sleeve on the hammer device. When a blow is struck by the hammer on the cartridge 16, a member 19 at the inner end is driven in and releases the gas. For example, the member 19 fits in a hole 48, Fig. 11 of the cartridge 1, and wedges a post 42 off a seat 44, thereby allowing 'the gas pressure to break a disc 38. Or this disc is omitted and the front end 43 of the post 42 acts as a valve. In the form shown in Fig. 25, the member driven into the cartridge takes the form of a punch 59 located in the end of the cartridge 1 by a pin 61 and adapted to pierce a closing disc 57. In a modification, the punch is arranged at the other end of the cartridge and is driven in directly by the blow of the hammer. The cartridge may be filled to a pressure of 5000 to 10000 lbs per sq. in. through a laterally disposed screw down valve with ports for the passage of the gas.