| 摘要 |
PROBLEM TO BE SOLVED: To provide a cleaning swivel for use in a double-pipe excavating method employing a down-the-hole hammer, which can solve various problems. SOLUTION: The cleaning swivel is formed of a top sub 2, an outer rod sub 3, an inner rod sub 4, and a swivel case 5. The top sub 2 is connected to a drill head and has an air channel 9 formed therein. The outer rod sub 3 is fixed to the top sub 2 and has a hydraulic cylinder chamber 15 formed therein at a location between its annular diaphragm portion 14 and the top sub 2. The inner rod sub 4 is inserted into the outer rod sub 3, and has its rear end and its intermediate portion slidably fitted into the air channel 9 and the annular diaphragm portion 14, respectively. The inner rod sub 4 is provided with a piston 14. The swivel case 5 has splines 18, 19 for transmitting torque from the outer rod sub 3 to the inner rod sub 4, and an annular air chamber 23, annular liquid chambers 24a, 24b, and an annular cuttings chamber 25 which are located inside a peripheral surface thereof. The swivel case 5 also has an air inflow port 26, liquid outlet ports 27a, 27b, and a cuttings exhaust port 28 which are located on the peripheral surface thereof and communicate with the annular air chamber, the annular liquid chambers and the annular cuttings chamber, respectively. COPYRIGHT: (C)2003,JPO
|
