Apparatus and method for producing a locking ring on a closure cap for a container

A method for producing a closure cap for a container, comprising the following steps:

• providing a closure cap blank;
• producing a locking ring by generating a slot geometry in a shell of the closure cap blank in a cutting procedure by rolling the shell along a plurality of cutting blades of a stationary cutting knife, said plurality of cutting blades extending along a cutting section and a cutting edge profile of each of the former corresponding to the slot geometry to be generated;
• wherein the slot geometry comprises portions which in relation to a rotation axis of a support mandrel extend at an angle of less than 90°;
• wherein a groove geometry of the support mandrel includes an axial extent, the groove geometry including (i) a first portion that is aligned so as to be perpendicular to the rotation axis of the support mandrel and having a smaller extent of the groove geometry, and (ii) a second portion that extends at an angle less than 90 degrees with respect to the axis of rotation of the support mandrel and having a larger extent of the groove geometry, to provide space for engagement of the cutting edges of the cutting blades due to rotational movement of the supporting mandrel;
• wherein the shell while rolling is supported by a support mandrel which is mounted so as to be rotatable about a rotation axis oriented perpendicularly to the cutting section;
• wherein a support portion of the support mandrel which during the cutting procedure lies opposite the cutting blade and by way of which the support mandrel in a momentary cutting region bears on a shell internal face of the shell, is interrupted in a region of the slot geometry to be generated by forming the groove geometry corresponding to the slot geometry to be generated;
• and
• wherein a rotating movement of the support mandrel takes places so as to be synchronized with an advancing movement of the shell along the cutting section with a rotating movement of the support mandrel about the rotation axis in such a manner that the groove geometry of the support mandrel in a momentary cutting region is moved past the plurality of cutting blades so as to be congruent with the cutting edge profile of the plurality of cutting blades, in such a manner that a portion of the groove geometry is disposed opposite the cutting blades at every moment during the cutting procedure in a momentary cutting region of the cutting edges.

An apparatus for producing a locking ring on a closure cap for a container, comprising:

• a) a stationary cutting knife having a plurality of cutting blades extending along a cutting section, the plurality of cutting blades each having a cutting edge profile and being configured to simultaneously penetrate a shell of a closure cap blank, each cutting blade of the plurality of cutting blades providing a slot geometry in the shell of the closure cap blank corresponding to the cutting edge profile of each cutting blade of the plurality of cutting blades so as to be between a main part of the closure cap and the locking ring, wherein the plurality of blades of the cutting knife are disposed on top of one another;
• b) a transport installation for transporting the closure cap blank along the cutting section, wherein the transport installation comprises a support mandrel for supporting the shell of the closure cap blank, in particular for supporting directly a shell internal side, in such a manner that the shell during a cutting procedure is rolled along the plurality of cutting blades, wherein the support mandrel has a rotatable mounting by way of which said support mandrel is mounted so as to be rotatable about a rotation axis oriented perpendicularly to the cutting section;
• wherein
• c) a groove geometry which corresponds to the slot geometry to be produced is configured in a support portion of the support mandrel which during the cutting procedure lies opposite the plurality of cutting blades, wherein the groove geometry includes an axial extent, the groove geometry including (i) a first portion that is aligned so as to be perpendicular to the rotation axis of the support mandrel and having a smaller extent of the groove geometry, and (ii) a second portion that extends at an angle less than 90 degrees with respect to the axis of rotation of the support mandrel and having a larger extent of the groove geometry, to provide space for engagement of the cutting edges of the cutting blades due to rotational movement of the supporting mandrel, such that the groove geometry of the support mandrel is configured so as to be congruent with a cutting edge profile of each cutting blade of the plurality of cutting blades when the support portion is moved past the cutting blade, in such a manner that a portion of the groove geometry is disposed opposite the cutting blade at every moment during the cutting procedure in a momentary cutting region of the cutting edge;
• d) the apparatus comprises a synchronizing installation by means of which an advancing movement of the transport installation along the cutting section is able to be synchronized with a rotating movement of the support mandrel about the rotation axis;
• and
• e) the cutting-edge profile of the cutting knife being constructed in a modular manner by assembling a plurality of rectilinear but relatively inclined portions of different cutting elements.