Closing cap for a container and its production method

1. A closing cap ( 1 ) for a container ( 2 ), comprising a lateral wall ( 3 ) extending around an axis (Z) and a transversal wall ( 4 ) positioned at one end of the lateral wall ( 3 ), a separation line ( 5 ) being provided on the lateral wall ( 3 ) to define:

a retaining ring ( 301 ), which is configured to remain anchored to a neck ( 201 ) of the container ( 2 ) and extends as far as a free edge ( 304 );

a closing element ( 302 ) removably engageable with the neck ( 201 ), so as to open or close the container ( 2 ); wherein

the separation line ( 5 ) extends about the axis (Z) and is circumferentially interrupted to form in the lateral wall ( 3 ) a joining zone ( 305 ), which extends for a first angle (α), in which the retaining ring ( 301 ) and the closing element ( 302 ) are joined; wherein the cap ( 1 ) comprises

a tab ( 308 ), made in the joining zone ( 305 ), which extends circumferentially for a second angle (β) and is connected to the joining zone ( 305 ); the retaining ring ( 301 ) comprising:

a retaining portion ( 303 ) and a free portion ( 306 ), wherein the retaining portion ( 303 ) comprises an engagement element configured to engage internally with a locking ring ( 202 ) of the neck ( 201 ) during a passage from a closed condition to an open condition of the closing element ( 302 ), the retaining portion ( 303 ) being circumferentially interrupted to define the free portion ( 306 ) at least in the second angle (β) in which the tab ( 308 ) extends, and wherein the free portion ( 306 ) comprises a movement element which extends circumferentially at least in the second angle (β) and is configured, during said passage, to allow a movement of the free portion ( 306 ) along an axis parallel to the axis (Z), wherein the retaining portion ( 303 ) and the free portion ( 306 ) extend up to the free edge ( 304 ) of the retaining ring ( 301 ) and wherein the engagement element of the retaining portion ( 303 ) comprises a plurality of protruding elements which project from the free edge ( 304 ) towards the inside and which have at most a first length.

2. The cap according to claim 1 , wherein the free portion ( 306 ) extends for a third angle (γ), at least equal to the first angle (α).

3. The cap according to claim 1 , wherein the tab ( 308 ) is connected to the joining zone ( 305 ) by a hinge zone ( 310 ), about which the tab ( 308 ) may optionally bend and comprises a bottom edge ( 309 ), which is positioned on the opposite side relative to the hinge zone ( 310 ) and is interposed between the hinge zone ( 310 ) and the free edge ( 304 ) of the retaining ring ( 301 ), and a pair of lateral edges ( 311 ), which extend from the hinge zone ( 310 ), the lateral edges ( 311 ) being transversal to the bottom edge ( 309 ).

4. The cap according to claim 3 , wherein the tab ( 308 ) comprises an outer part ( 308 a ), made in the retaining ring ( 303 ) and an inner part ( 308 b ), made in the closing element ( 302 ), which are separated respectively from the retaining ring ( 301 ) and from the closing element ( 302 ) by respective stretches of the lateral edges ( 311 ).

5. The cap according to claim 3 , wherein the lateral edges ( 311 ) are parallel to each other and parallel to the axis (Z) and wherein on the lateral wall ( 3 ) there are two cut lines ( 6 ) which extend parallel to the axis (Z) which define the respective lateral edges ( 311 ) of the tab ( 308 ), wherein the cut lines ( 6 ) are equal in length and have first ends between which is defined the hinge zone ( 310 ).

6. The cap according to claim 4 , wherein the lateral edges ( 311 ) are parallel to each other and parallel to the axis (Z) and wherein on the lateral wall ( 3 ) there are two cut lines ( 6 ) which extend parallel to the axis (Z) which define the respective lateral edges ( 311 ) of the tab ( 308 ), wherein the cut lines ( 6 ) are equal in length and have first ends between which is defined the hinge zone ( 310 ), wherein the hinge zone ( 310 ) is positioned in the closing element ( 302 ) and wherein the cut lines ( 6 ) extend at least inside the closing element ( 302 ) to define the inner part ( 308 b ) of the tab ( 308 ).

7. The cap according to claim 5 , wherein on the lateral wall ( 3 ) there are two further cut lines ( 6 ′), which extend inside the closing element ( 302 ) and wherein one extends from a first end ( 501 ) of the separation line ( 5 ) and the other extends from a second end ( 502 ) of the separation line ( 5 ).

8. The cap according to claim 1 , wherein the free portion ( 306 ) extends circumferentially for a third angle (γ), which is between 10° and 150°, preferably between 30° and 150°, even more preferably between 50° and 150°.

9. The cap according to claim 1 , wherein the second angle (β) is between 10° and 60°, preferably between 20° and 40°, even more preferably equal to 25°.

10. The cap according to claim 1 , wherein the first angle (α) is between 20° and 90°, preferably between 20° and 40°.

11. The cap according to claim 1 , wherein the tab ( 308 ) is connected to the joining zone ( 305 ) by a hinge zone ( 310 ), about which the tab ( 308 ) can optionally bend.

12. The cap according to claim 1 , wherein the movement element is made as a movement wall, which projects from the free edge ( 304 ) towards the inside and has a second length, less than the first length, defining a recess ( 307 ) which is interposed between circumferentially opposite ends of the retaining portion ( 303 ) and is delimited by the movement wall.

13. The cap according to claim 1 , wherein the movement element is made as a recess ( 307 ) which extends as far as the free edge ( 304 ), which is interposed between circumferentially opposite ends of the retaining portion ( 303 ) and is delimited by the free edge ( 304 ).

14. A method for making a cap ( 1 ) for a container ( 2 ) comprising the following steps:

providing a lateral wall ( 3 ) extending around an axis (Z) and a transversal wall ( 4 ) positioned at one end of the lateral wall ( 3 );

cutting a separation line ( 5 ) on the lateral wall ( 3 ) to form:

a retaining ring ( 301 ), configured for anchoring the retaining ring ( 301 ) to the neck ( 201 );

a closing element ( 302 ) removably engageable with the neck ( 201 ), so as to open or close the container ( 2 );

wherein the step of cutting the separation line ( 5 ) comprises interrupting the cut, to leave joined the retaining ring ( 301 ) and the closing element ( 302 ) in a joining zone ( 305 ), which extends angularly for a first angle (a); wherein the method also comprises the step of

making a tab ( 308 ) in the joining zone ( 305 ), which extends circumferentially for a second angle (β); and wherein the method also comprises the step of providing in the retaining ring ( 301 ) a retaining portion ( 303 ), for engaging internally with a locking ring ( 202 ) of the neck ( 201 ) during a passage from the closed condition to the open condition of the closing element ( 302 ) and a free portion ( 306 ), equipped with a movement element to allow a movement of the free portion ( 306 ) along an axis parallel to the axis (Z) during said passage.

15. A closing cap ( 1 ) for a container ( 2 ), comprising a lateral wall ( 3 ) extending around an axis (Z) and a transversal wall ( 4 ) positioned at one end of the lateral wall ( 3 ), a separation line ( 5 ) being provided on the lateral wall ( 3 ) to define:

a retaining ring ( 301 ), which is configured to remain anchored to a neck ( 201 ) of the container ( 2 ) and extends as far as a free edge ( 304 );

a closing element ( 302 ) removably engageable with the neck ( 201 ), so as to open or close the container ( 2 ); wherein

the separation line ( 5 ) extends about the axis (Z) and is circumferentially interrupted to form in the lateral wall ( 3 ) a joining zone ( 305 ), which extends for a first angle (a), in which the retaining ring ( 301 ) and the closing element ( 302 ) are joined; wherein the cap ( 1 ) comprises

a tab ( 308 ), made in the joining zone ( 305 ), which extends circumferentially for a second angle (β) and is connected to the joining zone ( 305 ); the retaining ring ( 301 ) comprising:

a retaining portion ( 303 ) and a free portion ( 306 ), wherein the retaining portion ( 303 ) comprises an engagement element configured to engage internally with a locking ring ( 202 ) of the neck ( 201 ) during a passage from a closed condition to an open condition of the closing element ( 302 ), the retaining portion ( 303 ) being circumferentially interrupted to define the free portion ( 306 ) at least in the second angle (β) in which the tab ( 308 ) extends, and wherein the free portion ( 306 ) comprises a movement element which extends circumferentially at least in the second angle (β) and is configured, during said passage, to allow a movement of the free portion ( 306 ) along an axis parallel to the axis (Z), wherein the retaining portion ( 303 ) and the free portion ( 306 ) extend up to the free edge ( 304 ) of the retaining ring ( 301 ) and wherein the engagement element is shaped like a continuous or interrupted enlargement, which from an inner surface of the retaining portion ( 303 ) projects towards the axis (Z) to engage with the locking ring ( 202 ).

16. The cap according to claim 15 , wherein the movement element of the free portion ( 306 ) is made like a wall in which the enlargement is absent.