Method for detaching or separating a sealing film or foil sealingly attached to the rim of the neck of a bottle, or the like, and a screw cap for implementation of said method

A screw cap having a top section, a sleeve section having a female thread, and an open end, that enable screwing of the cap onto, and unscrewing from, a container neck having a rim and a male thread, which neck is hermetically sealed by a sealing film which has a radially overlapping circumferential zone engaging the rim and which is sealingly attached to a circular sealing surface of the rim of the neck, and which is detached and/or destroyed in order to expose the contents of a bottle;

• the cap comprising:
• at least one detachment knife disposed on the sleeve section between the female thread and the top section and extending along an inside periphery of the sleeve section in its starting position prior to being screwed down, the at least one detachment knife having a knife edge extending obliquely toward the open end of the screw cap and inwardly toward the center axis of the neck and the screw cap, wherein the distance of the detachment knife edge from the center axis prior to screwing down is less than an outside diameter (D) of the rim of the neck,
• the at least one detachment knife being resiliently displaced as the screw cap is screwed down onto the neck of the container, and, due to the pressure imposed by the rim of the neck and the circumferential zone of the sealing film, the detachment knife resiliently bends the knife edge upwardly and comes to rest on an outer periphery of the neck above the male thread and beneath the radially-overlapping circumferential zone of the sealing film, and the at least one detachment knife being resiliently deformed and resiliently pre-stressed toward the center axis once the cap is screwed down, and
• wherein when the cap is unscrewed, the knife edge of the detachment knife is disposed initially obliquely in relation to the sealing film and toward the center axis, and then, due to its resiliency by springing back, continuously penetrates further radially inwardly toward the center axis between the overlapping circumferential zone of the sealing film and the rim of the neck of the bottle, wherein the sealing film is engaged by the knife edge to be progressively separated from the rim of the bottle toward the center axis and to be stored in the screw cap between the detachment knife and the top section.

A method for making a cap for the neck of a container, a rim of the neck having a sealing film on the rim surface and the neck having a male thread and a center axis, and the cap having a female thread complementary to the male thread and capable of being screwed down onto the male thread of the neck and unscrewed at any later point in time, the method comprising:

• providing a detacher before the screw cap is screwed down onto the neck of the container, for unsealing at least part of the film or foil from said rim;
• installing an intermediate layer for being pressed onto the sealing film by an inside surface of a top section of the cap as the screw cap is screwed down onto the neck of the container,
• adhering said intermediate layer to the inside surface;
• and
• adhering by gluing or welding to a surface of the sealing film in such a
• way that the sealing film firmly adheres to the inside surface for at least partially detaching the sealing film by the intermediate layer adhered in the screw cap when the cap is unscrewed from the neck of the container.

A screw cap for a container having a neck with a male thread, and a sealing film that is sealingly attached to a circular sealing surface of a rim of the neck, the cap having a top section and a sleeve section having a female thread corresponding to the male thread and an open end for screwing onto, and unscrewing from, the neck, the cap comprising:

• means for removing at least a portion of the sealing film having a detacher in the form of an inverted, anvil-like, inner, plate-like projection facing an inside surface of the top;
• an intermediate layer under the anvil-like projection;
• a first adherent to engage the inside surface;
• and
• having a second adherent to bear against the surface of the sealing film when the screw cap is screwed down.