Abstract: The closure has a body (1) and a guarantee ring (2) connected to it. The hooks (5) applied to the guarantee ring (2) and intended to separate the latter (2) from the body (1) of the closure upon removal of the closure from the container are each equipped with a slide wedge (8). This wedge may perferably be in the middle of the hook which extends longitudinally along the periphery of the closure. The wedge (8) has a slide face (11) of a width (b) that is about a quarter of the length (L) of the hook (5). The slide face (11) is inclined to the interior wall (4) of the guarantee ring preferably at an angle (.alpha.) of 31 degrees and initiates at the lower rim (9) of the guarantee ring in order to improve the machine-operated placing of the closure onto the container.

Abstract: The closure device has a guarantee ring (4) of which the inner (5) and outer (6) walls are so formed so to be easily separated from the injection mold. The inner wall (5) forms an angle (.alpha.) with the inner wall (8) of the cylindrical closure, respectively with its longitudinal axis (A). The outer wall (6) has a rounded profile (11) directly at the limit of the strips (3) to provide the wall with the desired thickness (d) at a determined location (12). Said rounded profile (11) facilitates the extraction of the closure (1 ), with the strips (3) and the guarantee ring (4), from the funnel-like upper plunger (10), after withdrawal of the lower plunger (9).