VENTILATION APPARATUS FOR INJECTION MOLDS Russian patent published in 1997 - IPC

FIELD: metallurgy. SUBSTANCE: ventilation apparatus has valve device 1 with vent channel 10, air valve 12 disposed in vent channel 10 and drive 20,24,38 for closing air valve 12. Drive has force sensor 20, which is loaded with cast material 67 delivered from mold cavity into vent channel 10. Force sensor 20 is kinematically connected with movable locking part 14 of air valve 12. Force sensor 20 is made in the form of impact mechanism, whose working stroke is limited to portion of path, along which locking part 14 is moved, when air valve 12 is closed. Locking part 14 of air valve 12 is moved to closed position along path exceeding working stroke of impact mechanism 20 by force pulse delivered by this mechanism. Due to relatively short working stroke of impact mechanism 20 its kinematic energy is limited to such value, that it is perceived at rigid collision without taking specific measures to damp shocks and without damaging of apparatus. EFFECT: increased efficiency, simplified construction and enhanced reliability in operation. 17 cl, 9 dwg