The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 25, 1994
Filed:
Sep. 27, 1993
Hans F Edlund, Roanoke, VA (US);
Marvin L Haines, Roanoke, VA (US);
Reedrill, Inc., Denison, TX (US);
Abstract
A rotary blasthole drilling apparatus comprises a rotary blasthole drill and a drill automation control system. The apparatus includes a pull-down motor and a drill motor. The pull-down motor is driven by a pump to provide a pull-down force to a drill string, and the drill motor is used to provide rotary force to rotate a drill bit of the drill string. The drill automation control system includes a number of functional components including a user interface. Through the user interface, an operator sets a rotary torque set point that determines an amount of torque applied to the drill bit by the drill motor. The control system further includes a detector, for detecting pressure in the pump during a drilling operation, and a processor, which is operative under the control of a program stored therein and responsive to the rotary torque set point and signals from the pull-down pressure sensor for generating an error signal. The error signal is applied to a proportional control valve for modulating the pull-down pressure to provide a substantially constant torque to the system. The rotary torque set point may be varied as a function of one or more of the following external factors: excessive mast vibration, bit air pressure or bit plunge.