US Patent 7172406 Installation for blow molding thermoplastic polymer containers

An installation for blow molding thermoplastic polymer containers, including a blowing mold consisting of two portions capable of being assembled and a blowing device with a bell-type nozzle pressed in a sealed manner against a front mold surface mounted on the neck of a blank to be blow molded; a leaking device with a relatively large cross-section which extends from one contact surface of at least one mold portion up to the outside of the mold beyond the support of the bell of the nozzle on the surface. The high pressure blow molding fluid which can penetrate through an interstice between the mold portions which tend to be spaced apart from each other is at least mostly evacuated outside.