| 摘要 |
PURPOSE:To increase pneumatic feedable length greatly by providing >=1 projection on the internal surface of the pipe, used to pneumatically feed the wire body, continuously and spirally in the length direction. CONSTITUTION:Projections 2a - 2c are provided integrally on the inner wall surface of the pipe 1 continuously and spirally in the length direction. The air flow in the pipe 1 with the spiral projections 2a - 2b progresses spirally in the length direction, so the wire body gets on the flow and becomes easy to run at the center part and the possibility that the wire body contacts the internal wall surface of the pipe 1 decreases, so the frictional resistance is reduced. Further, the projections 2a - 2b are provided spirally on the wall surface of the pipe 1, so the resistance of the air flow on the surface of the wall 1 is large and the air easily flows at the center part where the resistance is small to flow at the maximum flow velocity at the center part. Consequently, the pneumatic feed distance can be increased greatly. |
