Improvements in or relating to spray devices for dust prevention when rock or coal boring

摘要

583,657. Percussive drills. HOWES, W. J. D. Nov. 14, 1944, No. 22432. [Class 124] For dust prevention, a tube 1 slides freely on the shaft 2 of a percussive drill and at its front end carries a ring-like water spraying device 5 located within a rubber or like flexible hood 4. The latter is reinforced or thickened where it receives the water pipe 6 and at its rear end 4a where it fits tightly on the tubular part 3a of a bell-mouthed element 3, the tubular part sliding on the tube 1 and being detachably secured to it as by means of a bayonet joint. The device 5 is brazed or spot-welded on to the element 3, and is fitted with a removable plug 5c for cleaning purposes.