| 摘要 |
<p>PURPOSE: To prevent enlargement of a puncture of a fiber web beforehand by setting a specified radius of curvature of a working part of a number of needles inserted in a needle board. CONSTITUTION: In the needle punching device, regarding to a group (a), (b), and (c) positioned back and forth in the passing direction of a fiber web formed by a needle board 2 rocking upwardly and downwardly by cooperation of a rocking link 10 with a crank mechanism 6, a working part having a reverse hook shaped section of a needle 3 corresponding to the group (a) which is the nearest to a pivotal axis 11 of the rocking link 10 is curved along an arc of a circle having a radius ra which is equal to an average interval of intervals from the pivotal axis 11 to all the needles 3 of the group (a). In a corresponding manner, each working part of the needle 3 corresponding to the groups (b) or (c) is curved along an arc of a circle having respective radius rb and rc each of which is equal to an average intervals of each interval from the pivotal axis 11 to all the needles 3 of each group to bring the conventional condition near to the punching condition when the needle board 2 is straightly moved upwardly and downwardly.</p> |
