| 摘要 |
A self-propelled carriage (28) has a housing (30) comprised of a center body section (51) and a pair of side sections (52) hinged (54) to the body section (51). Side sections (52) may be swung to an open "clamshell" like position for lowering of the carriage (28) onto the pipe (10) for travel along the pipe (10). Nozzles (72) for the discharge of abrasive particles, such as sand, are mounted for oscillating movement in a predetermined stroke to cover a predetermined outer surface area of the pipe (10) for cleaning the pipe and for providing a rough finish for the application of a coating. |
