Valve cartridge for dual check valve of punching tool for stope support in deep mining, has control piston with flow opening in piston head, and auxiliary piston arranged inside control piston between piston head and end of valve piston

摘要

The cartridge has a valve piston (78), a U-shaped control piston (76) and a piston spring (84), where the pistons and the spring are arranged in cartridge housings (72, 74). An end of the valve piston is adjustably accommodated in the control piston. The control piston exhibits a flow opening (88) in a piston head (86). An auxiliary piston (90) is arranged inside the control piston between the piston head and the end of the valve piston. The auxiliary piston exhibits a pivot, which is insertable into the flow opening in a loose fit.