Overcenter valve control system and method for drilling
This patent describes a drill feed control system. It comprises a feed cylinder having a first end and a second end, the cylinder being in fluid communication with the drill string, a first conduit in fluid communication with the first end; a second conduit in fluid communication with the second end; a reservoir; variable displacement pump means for displacing fluid from the reservoir, through the first conduit, to the first end of the feed cylinder; feed pressure control means for controlling the pressure of the variable displacement pump means; an overcenter valve connected to the second conduit; a pilot conduit communicating fluid in the first conduit to the overcenter valve; and a relief valve controlling pressure in the pilot conduit wherein pressure in the pilot conduit is held constant for a predetermined range of variable displacement pump pressures, the constant pilot conduit pressure being greater than a pressure in the reservoir.
- Assignee:
- Ingersoll-Rand Co., Woodcliff Lake, NJ (USA)
- Patent Number(s):
- US 5033266; A
- Application Number:
- PPN: US 7-398414
- OSTI ID:
- 5681292
- Resource Relation:
- Patent File Date: 25 Aug 1989
- Country of Publication:
- United States
- Language:
- English
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