Cap with tamper evident seal for containers, container comprising said cap and preform for producing said container

Abstract

There is described a container ( 1 ) with a thread ( 5 ) for a screw closing cap ( 3 ). The container has a neck ( 1 A) with a lower shoulder ( 1 X) that extends from the external surface ( 1 Z) of the neck, on which the thread ( 5 ) is formed toward the inside.

1 . A system comprising:
 a container comprising a body, a substantially cylindrically shaped end portion or neck forming an opening mouth, and a thread formed on an external surface of said end portion for engaging a closing cap, wherein a guiding shoulder is provided between the body of the container and the end portion for guiding the container in packaging plants, said guiding shoulder having an external diameter equal to a diameter of the external surface of the end portion of the container; and   a screw cap for said container, said screw cap comprising a lateral wall and an internal thread formed on an internal surface of the lateral wall, wherein said lateral wall comprises a security element configured to be irreversibly altered when the screw cap is removed from the container, wherein the screw cap is devoid of a tamper evident band along an end edge of said screw cap.   
     
     
         2 . The system as claimed in  claim 1 , wherein said end portion or neck extends from the opening mouth of the container to said guiding shoulder. 
     
     
         3 . The system as claimed in  claim 1 , wherein said shoulder has an internal diameter, smaller than the external diameter and equal to a minimum diameter of a shoulder connecting the end portion or neck to the body of the container. 
     
     
         4 . The system as claimed in  claim 1 , wherein said thread has at least one stop surface to cooperate with a security element of a closing cap. 
     
     
         5 . The system as claimed in  claim 1 , wherein said security element is arranged in an intermediate position of the lateral wall of the cap, between an end edge and a front wall of the cap. 
     
     
         6 . The system as claimed in  claim 1 , wherein said security element is projecting from the internal surface of the lateral wall toward a rotation axis of the cap. 
     
     
         7 . The system as claimed in  claim 1 , wherein said security element comprises at least one breakable element, which is broken when the cap is unscrewed from the container. 
     
     
         8 . The system as claimed in  claim 1 , wherein said security element is configured to interfere with the thread of the container when the cap is unscrewed from the container and suffer permanent deformation visible from an outside of the cap, as a result of interference between the security element and the container. 
     
     
         9 . The system as claimed in  claim 1 , wherein said security element comprises a tab formed in said lateral wall and having a distal end projecting toward an inside of the lateral wall to cooperate with the thread of the container, said tab comprising a proximal end, fastened to the lateral wall of the cap, opposite said distal end, said tab further comprising; an intermediate body normally housed in a seat produced in said lateral wall, the distal end projecting from said seat toward the inside of the lateral wall. 
     
     
         10 . The system as claimed in  claim 9 , wherein said tab extends tangentially along said lateral wall. 
     
     
         11 . The system as claimed in  claim 1 , wherein said security element comprises a tab, wherein a distal end of the tab has a front surface configured and arranged to abut against a stop surface produced on a thread of the container with which the cap is engaged, when the cap is unscrewed from the container. 
     
     
         12 . The system as claimed in  claim 1 , wherein said security element comprises a tab, said tab being joined to the lateral wall by at least one breakable element. 
     
     
         13 . A preform for producing a plastic container for a system according to  claim 1 , the preform comprising:
 a main body and a substantially cylindrical end portion or neck, said substantially cylindrical end portion or neck having a radial dimension greater than a radial dimension of the main body and said substantially cylindrical end portion or neck having a thread formed on a substantially cylindrical external surface of the substantially cylindrical end portion or neck having an external diameter;   a shoulder between the substantially cylindrical end portion or neck and the main body for forming a guiding surface of the container, said shoulder having a major diameter equal to the external diameter of said substantially cylindrical external surface and extending radially inward from the substantially cylindrical external surface of the substantially cylindrical end portion or neck of the preform towards the main body of the preform.   
     
     
         14 . The system as claimed in  claim 10 , wherein said tab comprises an extension substantially parallel to the thread of the cap. 
     
     
         15 . The system as claimed in  claim 11 , wherein the front surface is oriented approximately radially. 
     
     
         16 . The system as claimed in  claim 12 , wherein said at least one breakable element is formed by a bridge that joins the tab to an edge of a cutout or slit produced in said lateral wall and in which the tab is housed. 
     
     
         17 . The preform of  claim 13 , wherein the shoulder does not project radially outwardly beyond the external diameter of the substantially cylindrical external surface of the substantially cylindrical end part or neck.