Patent attributes
A viscous material feed system, comprises a feed tube that receives material expressed from a container; and a container evacuator comprising a chamber to hold a container to express material from the container to the feed tube and a plunger comprising a platen axially and slidably accommodated within the chamber, the platen comprising an O-ring fitted against a platen driving face; a full ring with tabs extending to secure the O-ring to the platen driving face with a circumferential surface exposed to the chamber and a vacuum breaker valve to the chamber that seals the platen face when in contact with container material and retains residual material adhering to the platen face when the valve is activated at a termination of a driving cycle of the platen through a container content.
