| 摘要 |
<p>A piercing device (1) includes an outer tube (2) rotatably supported on one (X1) of shafts, which are eccentrically arranged relative to each other, so that it can be driven for rotation. Piercing needles (33) are arranged on the other shaft (X2) in the outer tube (2). The piercing needles (33) are spaced from each other in a circumferential direction, and projecting radially outwards, and being independently rotatable. Each piercing needle is adapted to be extended and retracted relative to an outer surface of the outer tube, via a through hole (5) formed in the outer tube (2). A needle restraining member (6) is rotatably supported on the other shaft (X2), for transmitting torque to the piercing needles (33) when driven for rotation. The piercing needles (33) are rotatably supported on the other shaft (X2) via the needle support members (36a-36f), respectively. The piercing needles (33) and further piercing needles (33) which are rotatable integrally with the piercing needles (33) are fixedly connected to the needle support members (36a-36f) in axial juxtaposition with each other. The disclosed structure protects the piercing needles from unreasonable force, and prevents undesirable enlargement of pinholes and deformation of the rubber sheet. Further, even when the piercing needles are advanced into the rubber sheet and retraced therefrom, enlargement of the pinholes formed in the rubber sheet can be prevented. Moreover, an increased number of piercing needles can be arranged in axial juxtaposition with each other.</p> |
