Security valve for portable drilling machine, has transverse slide with piston and spring, displacing throttle valve to closed position when fluid pressure is less than threshold value

摘要

The valve (12) has a throttle valve (18) moving in a body between a closed position and an open position. A transverse slide (20) displaces the throttle valve to the closed position when fluid pressure is less than a threshold value. The slide has a piston (54) driving the throttle valve to the open position at which the piston contacts the low pressure fluid. A spring drives the throttle valve to the closed position. An Independent claim is also included for a portable drilling machine having a supply circuit including the security valve.