How To Properly Operate Pneumatic Roofbolters?

I. Pre-operation Preparation
1. Equipment Inspection
Ensure that air pressure, water pressure, and oil pressure are normal, that there are no sand or foreign objects remaining in the pipelines, and that the oil level in the lubricator is maintained at 80%-90%.
Perform a dry run test to check the motor rotation, leg lifting and lowering, and water circuit opening and closing functions to ensure there are no abnormalities.
2. Air Leg Adjustment
The knob must be fully opened to the fixed position. The length of the push rod must accurately match the valve group opening to avoid insufficient air intake or bending of the push rod.
45°-135° is the slow ascent range, preventing sudden movement of the air leg and avoiding safety accidents.
II. Drilling Operation Process
1. Starting the Hole
Adjust the leg thrust to the minimum setting (approximately 3cm penetration), start the air motor after the drill bit contacts the roof, and advance slowly for 20-50mm before gradually increasing the speed.
When working in hard rock, reduce the thrust. If stall torque occurs (sudden drop in speed), immediately stop the machine and retract the air leg.
2. Normal Drilling
Use a long drill rod with a small diameter drill bit to reduce resistance, maintain stable air pressure, and avoid excessive drill rod speed which can reduce transmission efficiency.
After drilling is complete, stop the water supply and run the machine dry for 2-3 minutes to blow out any remaining moisture.
III. Finishing and Maintenance
1. Equipment Cleaning
Close the air leg knob, rinse the exterior, and run the machine dry to prevent rust. Check for loose screws and damaged parts.
Air and water pipes must be emptied of residual air, and the drilling rig should be placed vertically in a safe area.
2. Fault Prevention
Regularly check the air leg seals (dust seal convex side facing upwards). Replace seals if there is air leakage.
Bottom plate screws are prone to loosening due to vibration and should be tightened every shift.