| 摘要 |
A blasting equipment arrangement with a blasting pistol (2) with at least one orifice (58) for ejecting a jet of blasting material. The orifice is connected to a compressed air supply channel (9,59) and a supply channel (10, 60) for the blasting material. The pistol has a screening device enclosing the length over which the jet will operate, with an outer opening (62) through which the jet can pass and which is intended for placing against a workpiece (64). A suction channel (11, 46) inside the screening device is connected to a suction unit (12) which maintains an underpressure in the suction channel such that blasting material is collected inside the screening device (39) and is transported to a container (4) via channel (11, 46). A control unit (16) is arranged such that in an initial position it maintains the compressed air supply to the orifice (58) closed, such that ejection of blasting material is prevented, and in a second position it allows compressed air to reach the orifice, such that blasting material is ejected. The suction channel (11, 46) opens partly into the opening (62) of the screening device (39) and partly into at least one closable opening (43) actuated by a trigger (41). The control unit (16) is arranged to assume its said initial position when the underpressure in the suction channel (11, 46) is less than atmospheric pressure in a pressure range down to a predetermined level, within which range the underpressure exists when one or both openings (62, 43) are open. The second position of the control unit is assumed when a larger underpressure, after passing of said pressure level, exists, which happens when both openings are almost closed. Blasting can only take place when the opening (62) of the screening unit (39) is closed by the object (64) to be blasted, and when at the same time the trigger (41) is actuated such that opening (43) is closed. |
