Tube head equipped with a lid, associated with an improved perforating cap which ensures protection of the lid prior to first use thereof

Abstract

A tube head assembly includes a tube head that includes a lid, a cap that includes a punch and a spacing ring. The ring is dimensioned in such a way as to keep the punch spaced from the lid when the cap is screwed onto the neck. Further, the ring and the cap include lugs and recesses co-operating in such a way as to limit their rotation relative to one another in the direction of screwing of the cap onto the neck.

What is claimed is: 
     
         1 . A tube head assembly comprising
 a tube head comprising a neck defining a longitudinal axis (Z-Z), a shoulder and a solid insert forming a lid closing said neck,   a cap comprising a punch adapted in order to cut the lid, said cap being adapted to be screwed onto said neck, and configured in such a way that when said cap is screwed onto the neck the punch is inserted into the neck, and   a removable spacing ring disposed bearing against the shoulder around the neck,   the ring and the cap being formed integrally in one piece and joined by material bridges, said ring having an internal diameter greater than the external diameter of said cap, so as to enable the cap to slide through the ring after breakage of said material bridges, said ring being dimensioned in such a way as to keep the punch spaced apart from the lid when the cap is screwed onto the neck;   characterised in that the ring and the cap comprise lugs and recesses co-operating in such a way as to limit their rotation relative to one another in the direction of screwing of the cap on the neck in order to prevent the breakage of said material bridges between the ring and the cap during the screwing of the cap onto the neck.   
     
     
         2 . The assembly according to  claim 1 , wherein said shoulder comprises projecting reliefs adapted to co-operate with non-return means arranged on an internal wall of the spacing ring in order to block rotation of the ring around the neck in the direction of unscrewing of the cap from the neck, such that the unscrewing of the cap in relation to the neck results in a breakage of the material bridges in order to detach the spacing ring from the cap. 
     
     
         3 . The assembly according to  claim 1 , wherein said punch is adapted in order after the withdrawal of the spacing ring from the assembly, when said cap is screwed in abutment against the shoulder, to achieve partial cutting of said lid in order to open said neck, the lid then being attached to the uncut part of the insert by a material bridge. 
     
     
         4 . The assembly according to  claim 1 , wherein said spacing ring comprises a plurality of ribs adapted to centre the spacing ring around the neck. 
     
     
         5 . The assembly according to  claim 1 , wherein said spacing ring has the shape of a portion of a circle of which a free end forms a tab which can be gripped by a user. 
     
     
         6 . The assembly according to  claim 1 , wherein said lugs and the recesses are configured in such a way as to define a spacing in the absence of a screwing force, said spacing being equal to 0.5 millimetres. 
     
     
         7 . The assembly according to  claim 1 , wherein said punch has a free end bevelled along a plane inclined with respect to the longitudinal axis (Z-Z) of the neck when the cap is screwed onto said neck. 
     
     
         8 . The assembly according to  claim 7 , wherein said bevelled free end has a semi-circular cross-section.