Hydraulic drill, in particular a rock drill
AssigneeOy Tampella AB
InventorsPekka Salmi, Rolf Strom
Life of this patent
Estimating the term…
Abstract
A hydraulic rock drill having a hydraulic drill drive motor, a hydraulic feed motor, and a hydraulic impact unit and associated pumps for supplying hydraulic fluid under pressure and provided with an automatic control system including a valve controlling the flow to the impact unit under the dependence of the pressure in the rotation motor circuit such as to reduce the power of the impact unit when the pressure in the drive motor circuit exceeds a permissible pressure and vice versa. Additionally, the hydraulic system preferably includes an additional flow control valve such as to decrease the feed power when the impact power increases.
Claims11
Hydraulic drill, in particular a rock drill, comprising a partial circuit containing an impact unit (7) with pumps (1A, 1B) and valves, a partial circuit containing a rotation motor (13) with pump and valve, and a partial circuit containing a feed motor (8) with pump and valves, characterized by a first valve (9) which derives its control from the partial circuit containing the rotation motor (13) in such manner that when the pressure in said partial circuit increases to exceed a given limit pressure the valve (9) begins to release flow from the partial circuit containing the impact unit (7) and to lower the pressure therein, whereby the power of the impact unit (7) decreases;
- and by a second valve (10) which derives its control from the partial circuit containing the rotation motor (13) in such manner that when the pressure in said partial circuit falls below a given limiting pressure the valve (10) begins to release flow from the partial circuit containing the impact unit (7) and to lower the pressure therein, whereby the power of the impact unit (7) decreases.
Dependencies are inferred from the claim text.