Apparatus of the reusable blasting, especially for the extraction of the coal

摘要

763,287. Blasting cartridges. IMPERIAL CHEMICAL INDUSTRIES, Ltd. April 20, 1955 [June, 16, 1954], No. 17673/54. Class 9 (1). A fluid pressure blasting. cartridge has a high tensile steel body 1 counterbored at the venting end to form an annular shoulder and receive a steel sleeve 4. The sleeve is cut away at its outer end to form with the body 1 a groove in which is seated an O-ring 7 of resilient rubber-like material. A venting head 10 is screwed into the outer end of the counter-bore and holds a steel rupture disc 8 against the O-ring. A distance piece 9 may be interposed between the disc 8 and the head 10. The sleeve 4 may be chamfered as in Fig. 3 so that the O-ring is seated in a groove of triangular section. The bore of the sleeve may be flared at the inner end.