The invention relates to a machine for manufacturing an object closed onto itself, which machine comprises first means for guiding and carrying a tire material to be arranged round the first means, characterized in that the first means can change form in controlled manner between a first form and a second form. The invention also relates to a machine for manufacturing an object closed onto itself, which machine comprises first means for guiding and supporting a tire material to be arranged round the first means, characterized in that the machine also comprises sixth means for folding the tire material arranged round the first means, for which purpose the sixth means comprise a number of folding members movable relative to each other, which folding members can engage on the tire material for folding and can therein move inside recesses provided for this purpose in the first means. The invention also relates to methods for manufacturing an object closed onto itself, comprising of arranging a tire material round first means provided for this purpose. Such machines and methods can be applied particularly in the production of tires for vehicles.