Automatic control system for rock drills

A drill system for automatically moving a rock drill to and from a surface to be drilled comprising:

• a pressurized fluid source,
• a driving means connected to receive pressurized fluid for moving a drill in response to the pressure and flow of the fluid;
• a connecting means for delivering the pressurized fluid from the fluid source to the driving means,
• a pressure means for measuring the pressure of the fluid delivered to the driving means to produce a signal indicating the fluid pressure level;
• a pressure differential means for measuring the fluid flow delivered to the driving means to produce a signal indicating the fluid flow rate;
• a sensing means responsive to the signals of the pressure means and pressure differential means for producing a signal indicating a preselected fluid pressure level and a preselected fluid flow rate;
• and
• a flow means for controlling the fluid flow to the driving means in response to a selected signal of the sensing means to thereby control the moving of a drill.

A rock drilling system comprising:

• a rock drill;
• a fluid motor having a fluid port connected to move the rock drill to and from a wall to be drilled by receiving pressurized fluid through a port;
• a conduit having a selected restriction connected to said port;
• a pressurized fluid source;
• a control valve connected between the fluid source and the conduit, said control valve having one position connecting the fluid source to the conduit and another position disconnecting the fluid source from the conduit;
• a means for moving the control valve to the one position to start the operation of a rock drill by supplying pressurized fluid to the conduit;
• a pressure switch connected to sense the pressure at the port and having a first condition when the pressure is above a preselected level and a second condition when the pressure is below a preselected level;
• a pressure differential switch connected to sense the pressure drop across the restriction in the conduit having a first condition when the pressure drop is below a preselected level and a second when the pressure drop is above a preselected level;
• and
• a positioning means for moving the control valve from the one position to the other position in response to the first conditions of the pressure switch and the pressure differential switch.