System for working in underground pipes using a compact servo driven flexible thrust chain at angles to the pipe from inside an inspection shaft

摘要

A compact system for working in underground pipes via inspection shafts has an L-shaped housing (1) which fits into a shaft and with a vertical servo cylinder (2) at the top and a horizontal connection for a thrust chain (15), as well as a reciprocating drive between the servo and the chain. The chain and the reciprocating drive are located in curved ducts (5, 15) in the housing. The reciprocating drive has a paws (6) which engages the thrust chain for repeated movements. A second pawl (13) fitted to the housing secures the thrust chain between servo cycles, i.e. it prevents elastic movements of the system during pauses. The system can be used to pull or push equipment and tools through underground pipe sections.