An apparatus for cutting tires of the type comprising a tread, side walls, and beads, so as to cut the side walls, the apparatus comprising: - a frame, - an accommodation zone intended to receive a tire to be cut in the frame, - lateral holding means (5, 6) for a tire received in the accommodation zone, - blades arranged transversely, oriented toward a sidewall of a tire received in the accommodation zone, said blades being mounted to slide between a separated position of disengagement of the tread and a working position in which they penetrate into the sidewall of a tire in order to separate the tread from its side walls, and - a controlling logic control governing the sliding of said blades between a separated position and a working position in order for the blades to penetrate into the side walls of a tire received in the apparatus only when they are above its tread, charactized in - said accommodation zone comprise a pair of drive rollers (10, 11) for a tire placed on the drive rollers (10, 11) in the accommodation zone, - two support structures (3', 3") are mounted above and on either side of the accommodation zone, - said holding means are mounted on at least one of the two support structures (3', 3"), - a detector, in particular an optical detector, capable of detecting a void central zone of a tire received in the accommodation zone, lying between the inner diameter of the beads of the tire, said detector being arranged on at least one of the two support structures (3', 3"), - blades are mounted on the support structures (3', 3"), - a controlling logic control governing the rotation of at least one roller of the pair of rollers (10, 11), and - the lateral holding means (5, 6) comprise: - a sliding jaw capable of pressing against the bead of a tire received in the apparatus, and - a part with two branches each bearing a wheel arranged to be inserted into a tire received in the apparatus and whose two branches are capable of coming into contact with an inner surface of the tread of the tire, - the jaw and the part are diametrically opposed relative to the inner circumference of a tire received in the apparatus, and - the blades, when they are in working position, penetrate into the side walls of a tire when the blades are in proximity to or received between the two branches so as to stabilize the cutting zone. - a frame, - an accommodation zone intended to receive a tire to be cut in the frame, - lateral holding means (5, 6) for a tire received in the accommodation zone, - blades arranged transversely, oriented toward a sidewall of a tire received in the accommodation zone, said blades being mounted to slide between a separated position of disengagement of the tread and a working position in which they penetrate into the sidewall of a tire in order to separate the tread from its side walls, and - a controlling logic control governing the sliding of said blades between a separated position and a working position in order for the blades to penetrate into the side walls of a tire received in the apparatus only when they are above its tread, - said accommodation zone comprise a pair of drive rollers (10, 11) for a tire placed on the drive rollers (10, 11) in the accommodation zone, - two support structures (3', 3") are mounted above and on either side of the accommodation zone, - said holding means are mounted on at least one of the two support structures (3', 3"), - a detector, in particular an optical detector, capable of detecting a void central zone of a tire received in the accommodation zone, lying between the inner diameter of the beads of the tire, said detector being arranged on at least one of the two support structures (3', 3"), - blades are mounted on the support structures (3', 3"), - a controlling logic control governing the rotation of at least one roller of the pair of rollers (10, 11), and - the lateral holding means (5, 6) comprise: - a sliding jaw capable of pressing against the bead of a tire received in the apparatus, and - a part with two branches each bearing a wheel arranged to be inserted into a tire received in the apparatus and whose two branches are capable of coming into contact with an inner surface of the tread of the tire, - the jaw and the part are diametrically opposed relative to the inner circumference of a tire received in the apparatus, and - the blades, when they are in working position, penetrate into the side walls of a tire when the blades are in proximity to or received between the two branches so as to stabilize the cutting zone.