Screw cap

Abstract

A screw cap of plastic material has a cap disk and an outer cap rim located adjacent at a right angle to a circumference of the cap disk. The cap rim has an internal thread for closing a filling and/or removal socket of a container for transporting and storing liquid, and a central bung socket arranged retracted in the cap disk, wherein the bung socket has an internal thread for screwing in a bung plug. The bung plug has a cylindrical threaded sleeve with an external thread for screwing in a threaded bore of the bung plug of the cap, and a sealing end provided with a conical multiple seal of sealing rings which, when the bung plug is screwed in, are pressed against a conical inner sealing surface of a sealing projection located adjacent the threaded bore of the bung socket of the screw cap.

1 . A screw cap of plastic material comprising a cap disk and an outer cap rim located adjacent at a right angle to a circumference of the cap disk, wherein the cap rim has an internal thread for closing a filling and/or removal socket of a container for transporting and storing liquid, and a central bung socket arranged retracted in the cap disk, wherein the bung socket has an internal thread for screwing in a bung plug, the bung plug having a cylindrical threaded sleeve with an external thread for screwing in a threaded bore of the bung plug of the cap, and a sealing end provided with a conical multiple seal comprised of sealing rings which, when the bung plug is screwed in, are pressed against a conical inner sealing surface of a sealing projection located adjacent the threaded bore of the bung socket of the screw cap. 
   
   
       2 . The screw cap according to  claim 1 , comprising four sealing rings integrally formed at the sealing end of the threaded sleeve of the bung plug, wherein the sealing rings are spaced apart by grooves and are arranged concentrically relative to a longitudinal axis of the plug, wherein the diameters of the sealing rings become smaller in a screwing-in direction of the bung plug corresponding to the conical inner sealing surface of the sealing projection of the bung plug of the screw cap. 
   
   
       3 . The screw cap according to  claim 2 , wherein the sealing rings have rounded-off sealing rims. 
   
   
       4 . The screw cap according to  claim 1 , comprising a bung plug with an integrated aerating device. 
   
   
       5 . The screw cap according to  claim 1 , comprising a bung plug having an integrated aerating and ventilating device. 
   
   
       6 . The screw cap according to  claim 1 , wherein the cap and the bung plug are injection-molded parts of plastic material. 
   
   
       7 . A screw cap of plastic material comprising a cap disk and an outer cap rim located adjacent at a right angle to a circumference of the cap disk, wherein the cap rim has an internal thread for closing a filling and/or removal socket of a container for transporting and storing liquid, and a central bung socket arranged retracted in the cap disk, wherein the bung socket has an internal thread for screwing in a bung plug, the bung plug having a cylindrical threaded sleeve with an external thread for screwing in a threaded bore of the bung plug of the cap, and a sealing end which comprises a single-piece sealing rings having a rounded-off sealing rim which is pressed against a conical inner sealing surface of a sealing projection located adjacent the threaded bore of the bung socket of the screw cap. 
   
   
       8 . A screw cap of plastic material comprising a cap disk and an outer cap rim located adjacent at a right angle to a circumference of the cap disk, wherein the cap rim has an internal thread for closing a filling and/or removal socket of a container for transporting and storing liquid, and a central bung socket arranged retracted in the cap disk, wherein the bung socket has an internal thread for screwing in a bung plug, the bung plug having a cylindrical threaded sleeve with an external thread for screwing in a threaded bore of the bung plug of the cap, and a sealing end which is comprised of a conical sealing rim which, when the bung plug is screwed in, is pressed against a conical inner sealing surface of a sealing projection located adjacent the threaded bore of the bung socket of the screw cap.