Flexible shaft and roof drilling system
A system for drilling holes in the roof of a mine has a flexible shaft with a pair of oppositely wound, coaxial flat bands. One of the flat bands defines an inner spring that is wound right handed into a helical configuration, adjacent convolutions being in nesting relationship to one another. The other flat band defines an outer spring that is wound left handed into a helical configuration about the inner band, adjacent convolutions being nesting relationship with one another. A transition member that is configured to hold a rock bit is mounted to one end of the flexible shaft. When torque and thrust are applied to the flexible shaft by a driver, the inner spring expands outwardly and the outer spring contracts inwardly to form a relatively rigid shaft.
- Assignee:
- to Department of Energy
- Patent Number(s):
- US 4290494
- OSTI ID:
- 5829146
- Resource Relation:
- Patent File Date: Filed date 2 Oct 1978
- Country of Publication:
- United States
- Language:
- English
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