CUT-OFF METHOD IN ARRIVAL SHAFT AND STARTING SHAFT FOR DRIVING MACHINE

摘要

PROBLEM TO BE SOLVED: To improve the cut-off performance of an arrival shaft and a starting shaft for a driving machine.;SOLUTION: There is provided a cut-off device 22 formed of an entrance packing 24, a hollow pipe 26, and a support member 28. The packing 24 is formed of an annular flat plate 24a and a plurality of projections 24b. The hollow pipe 26 is formed of a rubber which is expandable when fluid such as compressed air or water is injected, and annularly arranged along an external peripheral edge of a mirror portion 20 in a manner enclosing the same. When the driving machine 10 is drawn into the arrival shaft 12, an internal edge of the packing 24 is elastically deformed along a progressing direction of the driving machine 10, and the projections 24b are brought into contact with an external peripheral surface of a main body 16. In this condition, the fluid is injected into the hollow pipe 26 to expand the same, whereby the projections 24a in a plurality of stages are press-contacted with the external peripheral surface of the main body 16.;COPYRIGHT: (C)2002,JPO