ABRASIVE BLASTING

摘要

A head unit (40; 140) for an abrasive blaster apparatus comprises a housing (41; 141) provided with a suction port (54; 154), and contains a blast nozzle (51; 51) and an end plate (44; 144). The housing (41; 141) has a rim (42; 142) for contacting a surface (43; 143) to be cleaned. The end plate (44; 144) is pivotably movable between an open position in which grit from the blast nozzle (51; 151) impacts the surface (43; 143) and a closed position in which the end plate (44; 144) is disposed to prevent grit from the blast nozzle (51; 151) passing beyond the rim (42; 142). The end plate (44; 144) is biased to the closed position. Either the end plate (44) is pivotably movable by contact between an extension (57) thereon and the surface (43) or the end plate (144) comprises means (157) external to the housing for moving the end plate (144) into the open position.