Title:
EXCAVATING ROD IN EXTENSIVE EXCAVATOR
Document Type and Number:
Japanese Patent JP3789290
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To solve a problem of a conventional extensive excavator, i.e., the problem of inefficient bothersome connection or separation of an inner pipe to or from an outer pipe, because, at every connection or separation of the inner pipe, a swivel is connected to the excavator to advance a piston rod of its pipe and a bit operating rod is squeezed to open an excavating bit.
SOLUTION: An expandable pipe is housed in a unit inner pipe at the tip of the inner pipe in a manner being capable of emerging out of an opening at the tip of the unit inner pipe, and the bit operating rod for rotating the excavating bit to an extensive position at the time of insertion to a central hole of a bit main body is protruded at the tip of the expandable pipe. As a result, even if the inner pipe is pulled up at the time of connection or separation of the inner and outer cylinders to each other or from each other, the unit inner cylinder is raised while having the bit operating rod inserted in the central hole of the bit main body, and therefore the inner and outer cylinders can be efficiently connected or separated to each other or from each other while having the excavating bit always held in the excavated position.
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Inventors:
Koichi Suga
Wataru Sotozaki
Wataru Sotozaki
Application Number:
JP2000211330A
Publication Date:
June 21, 2006
Filing Date:
July 12, 2000
Export Citation:
Assignee:
Nittoku Construction Co., Ltd.
International Classes:
E21B7/28; E21B10/32; E02D5/46; E21B7/30; (IPC1-7): E21B7/28; E21B7/30; E21B10/32
Domestic Patent References:
| JP10169354A | ||||
| JP2000064759A |
Attorney, Agent or Firm:
Minoru Fujii