| 摘要 |
Blast unit consisting of a blast nozzle (20) with at least one spray nozzle of blast material for outflow in a stream, a shield (30) around the stream with an outer opening, through which the stream can leave and which is designed to be set up with a work piece. From the interior of the shield a hose (23) extends to a main unit with housing (1). There is a suction unit in the housing, which is capable of maintaining an under pressure and a collection receptacle for the blast material. In addition there is a hose (35) for supply of compressed air to the spray nozzle, a hose (27) for supply of blast material to the spray nozzle from the receptacle. Through the spray nozzle extracted blast material is take up by suction force inside the shield (30) and led by the hose (23) to the receptacle. An air-regulator (17, 18) is set up to assume its first position when the absolute pressure in the housing exceeds a given value and to assume its second position when the pressure in the housing exceeds said value, the value is chosen so that it is exceeded if the shield's (30) opening is not tightly sealed to an object by which the pressure falls when air rushing in through the opening is prevented by the opening being kept pressed against an object.<IMAGE> |
