GB876582A - Improvements in or relating to sand blasting machines - Google Patents

Abstract

876,582. Sand blasting. BRACK, W. F. Sept. 24, 1959 [Sept. 24, 1958], No. 32520/59. Class 60. A sand blasting machine comprising a casing in which there is arranged a nozzle for projecting a mixture of compressed air and sand into the casing, the latter having an aperture to permit the sand to reach a work surface to be sanded, and having also a pipe, opening into said casing, for evacuating air and sand after use, the machine further comprising a packing arranged to ensure, during a sanding operation, a satisfactory seal between the casing and work surface, and a drive mechanism adapted to impart a rotary oscillatory movement to said packing to facilitate displacement of the machine on the work surface, is characterised in that the packing comprises a sleeve of flexible elastic material and has along part of its length a division which forms an inner portion closely fitted to said casing and an outer portion which is engaged by said drive mechanism. A nozzle 2 is adjustably mounted on a casing 1 having a portion 1a received in a groove 7 in a sleeve 4 of flexible, elastic material which contacts the work surface 5 to prevent lateral spread of sand. The portion 4b of the sleeve outside the groove 7 has holes 8 receiving pins 9 carried by a member 10 rotatably mounted on the casing 1. A compressed air turbine 13 drives an eccentric 12 located between the arms of a fork forming part of the member 10. A ring 14 of material softer than that of the sleeve 4 is secured to the sleeve 4 during moulding. In a modification, the ring of softer material is detachably secured to the sleeve 4. Air and used sand escape through a pipe 6.