METAL GROOVE-AND-TONGUE PLUG WITH PLASTIC PROTECTIVE LAYER Russian patent published in 2017 - IPC B65D39/08 

FIELD: packaging industry.

SUBSTANCE: groove-and-tongue plug for gas and liquid impermeable sealing of a bung hole having an internal thread of the vessel, in particular a steel barrel for storage and transport, in particular of hazardous liquid fillers, in the form of a cup-shaped base of metal with a disc-shaped bottom and an adjacent upward-open tubular annular part on which external thread is provided on the outer side. Inside the cup-shaped base, a geometric closure element in the form of a moulded sheet strip or an overlay is provided for inserting a tool for screwing and unscrewing the groove-and-tongue plug into the bung hole of the vessel. On the outer side of the annular part, a strong plastic layer is provided, on which corresponding external thread is formed on the outside to screw the groove-and-tongue plug into the internal thread of the bung hole. The plastic-coated outer side of the annular part of the cup-shaped base of metal remains completely free for any types of thread formation.

EFFECT: increased safety of use.

16 cl, 9 dwg