Method and drum for manufacturing a tyre, in particular a run-flat tyre

A method for manufacturing a tyre, the method comprising the steps of:

• providing a drum with a central axis and a main circumferential surface extending concentrically around said central axis at a first diameter,
• wherein the drum comprises a first shrink section and a second shrink section at spaced apart positions in the axial direction of the drum,
• wherein each of the first shrink section and the second shrink section is provided with a shrink surface that is radially movable;
• moving the shrink surfaces of the first shrink section and the second shrink section with respect to the central axis to a level position in which the shrink surfaces are at the first diameter and subsequently arranging a first tyre layer around the main circumferential surface of the drum and extending over the shrink surfaces at the first shrink section and the second shrink section;
• moving the shrink surfaces radially inwards with respect to the main circumferential surface and with respect to the central axis from the level position to a shrink position in which the drum, at the shrink surfaces, has a circumference with a second diameter that is smaller than the first diameter, while creating a partial vacuum between the shrink surfaces and the first tyre layer at the first shrink section and the second shrink section;
• and
• shrinking the first tyre layer onto the shrink surfaces in the shrink position under the influence of the partial vacuum,
• wherein (A) or (B) below is satisfied:
• (A) wherein, in providing the drum, the first shrink section and the second shrink section are provided with a plurality of first support plates and a plurality of second support plates, respectively, which are evenly distributed in the circumferential direction around the respective first and second shrink sections and arranged radially inside and radially movable with respect to the respective first and second shrink surfaces so as to support said respective shrink surfaces in the level position and the shrink position;
• or
• (B) wherein, in providing the drum, the first shrink section and the second shrink section are each provided with a plurality of profile segments that are placed adjacently to each other in a direction parallel to the central axis, wherein the plurality of profile segments are arranged to be individually movable in the radial direction between a level position in which all the profile segments extend up to the same radial distance from the central axis and a retracted position in which the profile segments are individually moved radially inwards to form a non-level support profile to support the shrink surface in the shrink position.