Drilling device and drilling method

摘要

The tool (1) has a flow limiter arranged in a hydraulic conduit unit (25) of an advancing device (21). The flow limiter includes a pressure-actuated adjusting member to adjust flow of hydraulic fluid in the hydraulic conduit unit in accordance with flow of a rinsing fluid (7) e.g. water, in channels (8, 11, 12). A transmitting unit transmits pressure of the rinsing fluid to the adjusting member and formed as one of mechanical, hydraulic and pneumatic elements for actuating the adjusting member in response to change of pressure of the rinsing fluid. An independent claim is also included for a method for forming bores in rock formations.