| 摘要 |
PROBLEM TO BE SOLVED: To provide an excavating head capable of surely detecting the blade expanding operation state of expansion blades. SOLUTION: The excavating head 11 is provided with a spiral blade 13 serving as a constant diameter excavating member with an invariable diameter, at a normally/reversely rotatable shaft 12. The expansion blades 15 expandable by resistance from an excavation wall surface in a reversely rotating time are turnably mounted to the spiral blade 13 by shaft members 16 through pressure receiving plates 14. Each expansion blade 15 is provided with a projecting part 18 locked to the rear end by a locking part 17 of the pressure receiving plate 14, and is formed to perform blade expanding operation by projecting a tip part 19 slightly from the outer diameter of the spiral blade 13 and receiving resistance from the excavation wall surface in the reversely rotating time by the tip. The pressure receiving plate 14 comprises an expansion blade operation space 23 between a pair of expansion blade journal plate parts formed in recessed shape. A confirmation pin 24 serving as an expansion blade confirming member damaged (deformed or broken) by the blade expanding operation of the expansion blade 15 is mounted into the expansion blade operation space 23. COPYRIGHT: (C)2010,JPO&INPIT
|
