| 摘要 |
PROBLEM TO BE SOLVED: To simplify structure by swinging a rod-like member radially provided on a cutter head by a jack device, and projecting a cutter bit through a connection tool. SOLUTION: An advancement and retraction amount adjusting device 8 is housed in a radial groove-like recess part 4 provided on the face plate 3 of a cutter head 2, and constituted of a jack device 9 provided on the outer peripheral end, a supporter 10 provided on the inner peripheral end, a rod-like member 11 and an annular connection tool 12 outward fitted on the member 11. The member 11 is stretched between the jack 9 and the supporter 10, swingably provided as the support pin 10 is made a center, and the connection tool 12 is swingable in the lengthwise direction of the groove 4 through the connection pin 6a of the base end of a cutter bit 6. While the bit 6 is worn, the member 11 is swung when a rod 9a is projected, and the projection amount of the bit 6 is large on the outer peripheral side in which a wear amount is large. At this time, the connection tool 12 is slid to the side of the jack 9, and the bit 9 is smoothly guided on a bit guide 7 without inclination. As a result, an amount of bit projection is easily controlled and the number of the jacks can be lessened. |
