Patent ID: 7690286

Claim:
A piercing device comprising: a first shaft having a first axis; a second shaft having a second axis, the second axis being eccentrically arranged relative to the first axis; an outer tube rotatably supported on the first shaft so that the outer tube can be driven for rotation; a plurality of needle support members that are independently rotatably supported on the second shaft and successively arranged along the second axis; a plurality of piercing needles arranged in a circumferential direction and supported on the second shaft via the needle support members, said plurality of piercing needles being spaced from each other in a circumferential direction, projecting radially outwards, and being each movable toward and away from other piercing needles in the circumferential direction, the piercing needles each being extendable and retractable relative to an outer surface of the outer tube via holes formed in the outer tube; a needle restraining member rotatably supported on the second shaft, for transmitting torque to the piercing needles when driven for rotation; and a plurality of guide bars that stop rotation of one or more of the plurality of piercing needles, one of the plurality of guide bars being positioned between two adjacent piercing needles, and disposed between the tip of one of the two adjacent piercing needles and the second axis.