FIELD: piston pumps handling rubber. SUBSTANCE: revolving cylindrical spool valve 1 has grooves 5 extending to lateral and end surfaces 12 communicating with intake 6 and grooves 5 extending to lateral and end surfaces 13 communicating with delivery side 7 (with discharge). Grooves 5 pass before port 4 giving passage to cylinder 2 with piston 3 of from it. Feed chamber is provided with member for mechanical forced motion of viscous matter. Provision is also made for devices for synchronization of piston motion in pumping chamber at rotation of distributing member. EFFECT: enhanced efficiency of check of open and closed positions of delivery opening of piston pump. 10 cl, 9 dwg
