Expandable belt and tread drum having irregular segment profiles

In a segment forming a portion of an outer cylindrical working surface of a belt and tread drum of the type useful for manufacturing vehicle tires, wherein the segment comprises an outer surface defining a portion of the cylindrical working surface, the outer surface having a longitudinal dimension parallel to a central axis of the cylindrical working surface and a circumferential dimension along a circumference of the cylindrical working surface, the improvement comprising:

• a plurality of alternating slots and fingers defined along the outer surface and extending along the circumferential dimension to define a longitudinal side margin, each finger being sized and shaped to at least partially mate with a corresponding slot of an adjacent segment;
• and
• wherein longitudinally adjacent slots and fingers along the outer surface are configured with differing lengths such that at least four consecutive fingers comprising in sequence a first finger, a second finger, a third finger, and a fourth finger are arranged along the longitudinal side margin and are configured such that the first finger has a first length, the second finger adjacent to the first finger has a second length shorter than the first length, the third finger adjacent to the second finger has a third length shorter than the first length and longer than the second length, and the fourth finger adjacent to the third finger has a fourth length shorter than the second length.

A belt and tread drum for use in the manufacture of vehicle tires comprising:

• a plurality of segments mounted in side-by-side relationship about a central axis for radial movement inwardly and outwardly with respect to the central axis, the segments including arcuate outer surfaces which collectively define an outer circumferential working surface of the drum, each segment including a plurality of alternating slots and fingers extending along a circumferential dimension of the drum to define opposite first and second longitudinal side margins of the segment, each finger of each first side margin being sized and shaped to at least partially mate with a corresponding slot of a second side margin of an adjacent segment, and each slot of each the first side margin being sized and shaped to at least partially mate with a corresponding finger of a second side margin of an adjacent segment, wherein the plurality of alternating slots and fingers are configured with differing lengths such that at least four consecutive fingers comprising in sequence a first finger, a second finger, a third finger, and a fourth finger are arranged along one of the longitudinal side margins and are configured such that the first finger has a first length, the second finger adjacent to the first finger has a second length shorter than the first length, the third finger adjacent to the second finger has a third length shorter than the first length and longer than the second length, and the fourth finger adjacent to the third finger has a fourth length shorter than the second length.