Tire building method and apparatus

An apparatus for building tires comprising:

• a plurality of belt ply supply means for supplying belt plies, respectively;
• first and second tread supply means for supplying treads, respectively;
• first and second band forming drums rotatable and expansible to increase diameters and contractible to decrease diameters;
• a tire forming drum on which a belt-tread band and a green case are combined to form a green tire;
• taking-out means for alternatively removing formed bands from the first and second band forming drums and transferring them to the tire forming drum;
• first moving means for successively moving the first band forming drum to the supply positions of the respective belt ply supply means, a supply position of the first tread supply means and a taking-out position of the taking-out means successively wind belt plies supplied from said belt ply supply means and tread supplied from said first tread supply means one over the other supply positions and to remove a formed band from the first band drum;
• and
• second moving means for successively moving the second band forming drum to the supply positions of the respective belt ply supply means, a supply position of the second tread supply means and the taking-out position of the taking-out means to successively wind belt plies supplied from said belt ply supply means and a tread supplied from said second tread supply means one over the other around the second band forming drum at the respective supply positions and to remove a formed band from the second band forming drum;
• the apparatus operable so that winding the belt plies and the tread around the first band forming drum and removing the band from the second band forming drum are performed simultaneously, and winding the belt plies and the tread around the second band forming drum and removing the band from the first band forming drum are performed simultaneously;
• said taking-out means comprising first and second frame bases movable toward and away from said first and second band forming drums, respectively, a third frame base movable toward and away from the tire forming drum, two annular members arrangeable on said first, second and third frame bases and having chucks, respectively, each of said chucks being expansible and contractible by receiving driving power from the frame base upon being arranged thereon to grasp a band on its outside and being able to hold the band even upon being removed from the frame base, and transfer mechanism provided between the first, second and third frame bases for transferring the annular member by grasping the band from the first and second frame bases to the third frame base on a tire forming unit and the annular member having no tire member from the third frame base to the first and second frame bases.

A method of building tires, comprising:

• a first step operation of (i) successively transferring a plurality of band forming drums to a plurality of belt ply supply positions for carrying out winding of a belt ply around each band forming drum, (ii) transferring said band forming drums to a plurality of tread supply positions for carrying out winding of a tread around said belt ply which has been would around each of said band forming drums, thereby forming a belt-tread band (BT band), and (iii) subsequently removing the BT band from said band forming drum and engaging the BT band with an annular member;
• a second step operation of (i) supplying an empty annular member and receiving an annular member returned in engagement with the BT band while, (ii) supplying another annular member in engagement with the BT band to a green case forming drum and receiving an empty annular member from which the BT band has been removed and transferred to the green case forming drum;
• and
• a third step operation of (i) receiving an annular member accommodating the BT band, (ii) transferring the BT band to a center region of a carcass which has been wound around the green case forming drum, and (iii) combining the BT band with the carcass thereby forming a green case;
• said method being carried out using a layout comprising a double BT band forming unit in which a first band forming drum and a second band forming drum for performing the first step are connected in series, with center axes of the band forming drums in alignment with each other, a transfer means for performing the second step and transferring the annular members in a direction perpendicular to the axes of the band forming drums, and the green case forming drum for performing the third step, having an axis which is parallel with the axes of the band forming drum, said method further comprising:
• starting the first step operation of the first band forming drum and the first step operation of the second band forming drum at different times, for alternately removing the BT bands from the first and second band forming drums;
• moving the transfer means between the first and second band forming drums for performing the second step operation so that the BT band which has been alternately removed from one of the first and second band forming drums is received by the annular member and transferred to the green case forming drum, while an empty annular member is returned from the green case forming drum and transferred to another one of the first and second band forming drums;
• and
• removing the BT band from the annular member for performing the third step operation wherein the BT band is combined with the carcass on the green case forming drum.