Patent ID: 8181769

Claim:
A workpiece transfer mechanism for transferring a workpiece to or from a workpiece boat, the workpiece boat having ringlike tables arranged in a longitudinal direction at predetermined pitches to each receive the workpiece placed thereon, the workpiece transfer mechanism comprising: a fork main body being movable forward and rearward with the workpiece placed thereon; a stopper member provided at an end portion of the fork main body and coming into contact with a circumferential edge of the workpiece; clamp means provided on a proximal end side of the fork main body and having a pressing portion, the pressing portion being movable forward and rearward relative to the fork main body along a longitudinal direction of the fork main body and coming into contact with the circumferential edge of the workpiece and pressing the workpiece toward the stopper member for clamping; and fork elevating means for lifting and lowering the fork main body along the workpiece boat; wherein when the workpiece is transferred to or from the workpiece boat, the fork main body is controlled to be inserted in a gap which is formed between two ringlike tables arranged next to each other in a longitudinal direction and the pressing portion of the clamp means is controlled not to be inserted in the gap.