Title:
SHOCK ABSORBING MECHANISM FOR HYDRAULIC HAMMERING DEVICE
Document Type and Number:
Japanese Patent JP3824112
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To reduce damage by smoothly buffering energy reflected from a shunk rod.
SOLUTION: A rock drill has a hammering mechanism and a chuck driver bush 13 for transmitting thrust to a shunk rod 2. In such a rock drill, a front damping piston 4 having thrust smaller than that of a rock drill main body 1, and a rear damping piston 5 having the larger thrust are arranged on a rear side of the chuck driver bush 13. An oil passage 51 and an oil supply passage 53 are formed between a front damping piston oil chamber 42 and a rear damping piston oil chamber 52. The oil passage 51 is interrupted, when the front damping piston 4 retreats and before the front damping piston 4 collides with the rear damping piston 5. The oil supply passage 53 has a check valve 55 which prevents oil flow from the front damping piston oil chamber 42 to the rear damping piston oil chamber 52, and allows oil flow from the rear damping piston oil chamber 52 to the front damping piston oil chamber 42.
Inventors:
Tsutomu Kaneko
Application Number:
JP19436697A
Publication Date:
September 20, 2006
Filing Date:
July 18, 1997
Export Citation:
Assignee:
Furukawa Metal Co., Ltd.
International Classes:
B25D17/24; E21B1/00; E21B1/26; (IPC1-7): B25D17/24; E21C3/20
Domestic Patent References:
| JP9109064A | ||||
| JP2262974A | ||||
| JP9011156A | ||||
| JP60002282U | ||||
| JP3018767U |
Attorney, Agent or Firm:
Tetsuya Mori
Yoshiaki Naito
Cui Shu Tetsu
Hiroshi Nemoto
Tadayuki Miyazaki
Yoshiaki Naito
Cui Shu Tetsu
Hiroshi Nemoto
Tadayuki Miyazaki
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