Patent ID: 8684057

Claim:
A driving apparatus of a building drum for a tire including a drum shaft of a double shaft structure, characterized by comprising: an outer shaft connected to an outer side shaft portion of the drum shaft; a middle shaft connected to an inner side shaft of the drum shaft; a single rotation drive source connected to the middle shaft by way of a rotation transmitting member; and a connecting and disconnecting clutch interposed between the middle shaft or the rotation transmitting member connected to be fixed to the middle shaft and the outer shaft; wherein the driving apparatus is constituted such that in connecting the clutch, rotation of the rotation drive source is transmitted to both of the middle shaft and the outer shaft, and in cutting the clutch, the rotation of the rotation drive source is transmitted only to the middle shaft; wherein the building drum for a tire is a building drum including a pair of left and right drum portions provided to be able to be proximate to and distant from each other along the drum shaft, the two drum portions are provided unrotatably and movably in the axial direction relative to the outer side shaft portion, the inner side shaft comprises a screw shaft formed with screw portions in directions reverse to each other at left and right portions in an axial direction, and portions of the outer side shaft portion in correspondence with the screw portions of the inner side shaft are formed with notches; wherein the two drum portions are connected to screwing portions relative to the screw portions of the inner side shaft by way of the notches of the outer side shaft portion, and thereby provided for an outer periphery of the outer side shaft portion to move to be proximate to or distant from each other by a feed operation by the two screw portions by rotation of the screw shaft relative to the outer side shaft portion, the outer shaft is connected to the outer side shaft portion of the drive shaft of the building drum, and the middle shaft is connected to the screw shaft; and wherein a portion of the outer shaft is formed with a notch in a slit shape in the axial direction, a screw portion is formed at a portion of the middle shaft in correspondence with the notch, an outer periphery of the outer shaft is provided with a moving member connected to a screwing portion relative to the screw portion of the middle shaft by way of the notch of the outer shaft and moved in the axial direction in accordance with rotation of the middle shaft, and the driving apparatus is constituted to detect and restrict a movement of making the two drum portions proximate to and distant from each other by rotation of the screw shaft of the drum shaft by detecting the movement of the moving member; and wherein at least one proximity sensor for detecting the movement is provided and is spaced apart from the outer shaft, and wherein said at least one proximity sensor includes a proximity sensor in a vicinity of an end portion of a range of movement of the moving member.