The internal combustion rock drill is a handheld rock drilling tool that is composed of a small gasoline engine, an air compressor, and a rock drill. A rock drill is a tool used to directly mine stone.
[pdf] Modern handheld rock drills incorporate ergonomic designs with vibration-dampening technology, ensuring operator comfort during extended use. They typically offer variable speed controls and multiple drill bit compatibility, accommodating different rock formations and drilling requirements.
[pdf] Holman Brothers Ltd. was an English mining equipment manufacturer founded in 1801 based in . Holman was Camborne's, and indeed Cornwall's largest manufacturer of industrial equipment. .
In 1881, brothers John Henry and James Miners Holman, had taken over running the business from their father John. They were offered the designs of a new by a James McCulloch. the brothers filed a joint patent with. .
Holman began to manufacture compressors. The first "Cornish" compressors were built to designs adapted from existing steam engines. In 1894, Holman manufactured the largest compresso.
[pdf] 
