Sealing heads for heat sealing the tops of continouously movable upright pouches are spaced angularly around a continuously rotatable turret and seal the pouches after steam has been introduced into the pouches and as the pouches move in an arcuate path extending around the turret. Each sealing head...http://www.google.com/patents/US4306400?utm_source=gb-gplus-sharePatent US4306400 - Packaging machine with continuous motion top sealer
