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Patent Searching and Data


Title:
KELLY BAR
Document Type and Number:
Japanese Patent JP2003336476
Kind Code:
A
Abstract:

To prevent a kelly swivel and a top guide from being damaged by their interference with each other when hoisting the kelly bar for being assembled to an earth drill.

A pin joint 27 in the upper end of the kelly bar 21 is extended longer than that of a conventional type kelly bar and the pin joint 27 is projected from a top guide 29 in its most contracted state. Thereby, the kelly swivel 30 attached to the pin joint 27 can be turned 90° or more from the upright state, so that when the kelly bar is hoisted from the ground for assembling the kelly bar, the kelly swivel 30 is prevented from contacting with the top guide 29 to eliminate any possibility of damage of the kelly swivel and the top guide. The pin joint is exposed to the outside, so that the kelly swivel can be easily attached thereto/detached therefrom with the top guide attached to the kelly bar, thus improving the assembling performance.


Inventors:
OCHIZAWA JUNICHI
Application Number:
JP2002000149477
Publication Date:
November 28, 2003
Filing Date:
May 23, 2002
Export Citation:
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Assignee:
SUMITOMO HEAVY IND CONSTR
International Classes:
E21B17/07; (IPC1-7): E21B17/07
Attorney, Agent or Firm:
林 孝吉