Disclosed is a tire building drum and method for operating the tire building drum, which tire building drum include a left section, a right section, a center section, and a support member for supporting the center section in the radially outward direction. The support member is movable together with the center section in the radially outward direction. The tire building drum further includes a blocking device for blocking the support member against movement in a radially inward direction when the center section is in the expanded position.

A drum for producing a tire casing blank comprises a support and sectors forming a circumferential face of the drum. Each sector has a circumferential outer face having a contour of general trapezoidal form and is mounted so as to be movable relative to the support in a non-radial predetermined direction relative to an axis of rotation of the drum and intercepting this axis.

A process for building tyres provides for building a carcass sleeve around a forming drum having an application diameter and two lateral half-portions axially moveable relative to each other. The carcass sleeve comprises at least one carcass ply coaxially engaged around each of the axially opposite end flaps thereof to an annular anchoring structure defining a fitting diameter smaller than the application diameter. The building of the carcass sleeve comprises: applying and stopping a leading end of a semi-finished product in form of continuous strip cut to size against a continuous surface of the forming drum; winding the semi-finished product in form of continuous strip cut to size circumferentially around the forming drum; joining a trailing end of the semi-finished product to the leading end at said continuous surface. The continuous surface is extended only partly around the forming drum. The semi-finished product, except for the leading end and the trailing end, is laid against a discontinuous circumferential surface of the forming drum adjacent to the continuous surface and belonging to the two lateral half-portions.

Disclosed is a tire building drum and method for operating the tire building drum, which tire building drum include a left section, a right section, a center section, and a support member for supporting the center section in the radially outward direction. The support member is movable together with the center section in the radially outward direction. The tire building drum further includes a blocking device for blocking the support member against movement in a radially inward direction when the center section is in the expanded position.

A carcass sleeve is situated in a radially external position with respect to a toroidal forming drum, arranged in a first radially contracted operative condition. The carcass sleeve is shaped according to a toroidal configuration while the forming drum is positioned inside the carcass sleeve. During shaping of the carcass sleeve, the forming drum is radially expanded up to a second radially expanded operative condition. Upon completed shaping, the carcass sleeve is coupled to the forming drum in the second operative condition. The forming drum, coupled to the shaped carcass sleeve, is arranged in proximity to at least one device for building at least one belt layer at a radially external position relative to the shaped carcass sleeve.

A process for building tyres employing a forming drum having circumferentially consecutive sectors that are radially movable between a contracted condition and an expanded condition in which the sectors are radially moved away from a geometric axis in order to define a radially external abutment surface. Each sector has circumferentially opposite coupling portions each having circumferential projections alternated with circumferential cavities. The projections of each sector are slidably engaged in the respective cavities of circumferentially adjacent sectors. From at least one of the projections, at least one support wing is extended having a first side and a second side that are respectively opposite. The first side coincides with a portion of the abutment surface and the second side at least partially overlaps one of the projections belonging to an adjacent sector.

An assembly defining a portion of an arcuate outer surface of a tire building drum, the assembly including first and second interlacing deck segments coupled to a central support member to be moved in a radially reciprocating manner, each of the interlacing deck segments including a plurality of center sections coupled together, a plurality of first grooves between the center sections, a plurality of first finger portions extending from the center sections away from the central support member, a plurality of second finger portions extending from the center sections in an opposite direction over the central support member, and a plurality of second grooves formed adjacent each of the second finger portions, wherein the second finger portions are arranged in parallel over the central support member, and the first grooves in each of the interlacing deck segments align with the second grooves of the other of the interlacing deck segments.

A forming drum has circumferentially consecutive sectors that are radially movable between a contracted condition and an expanded condition in which the sectors are radially moved away from a geometric axis in order to define a radially external abutment surface. Each sector has circumferentially opposite coupling portions, each having circumferential projections alternated with circumferential cavities. The projections of each sector are slidably engaged in the respective cavities of circumferentially adjacent sectors. From at least one of the projections, at least one support wing is extended having a first side and a second side that are respectively opposite. The first side coincides with a portion of the abutment surface and the second side at least partially overlaps one of the projections belonging to an adjacent sector. A process for building tyres employing the drum is also described.

A carcass sleeve is situated in a radially external position with respect to a toroidal forming drum, arranged in a first radially contracted operative condition. The carcass sleeve is shaped according to a toroidal configuration while the forming drum is positioned inside the carcass sleeve. During shaping of the carcass sleeve, the forming drum is radially expanded up to a second radially expanded operative condition. Upon completed shaping, the carcass sleeve is coupled to the forming drum in the second operative condition. The forming drum, coupled to the shaped carcass sleeve, is arranged in proximity to at least one device for building at least one belt layer at a radially external position relative to the shaped carcass sleeve.

A drum for building a green tire casing having: sectors that form a circumferential face of the drum, and at least one cam for controlling a radial movement of the sectors with respect to a rotation axis of the drum. The cam has two main faces and is designed such that a monotonous movement of the cam first of all causes the radial movement of some of the sectors by virtue of ramps situated on its first face without modifying a radial position of the other sectors, and then causes the radial movement of the other sectors by virtue of ramps situated on its second face, the movement of all of the sectors then being simultaneous.