| 摘要 |
Broadly, there is disclosed an improved apparatus and method for selecting controllably certain discrete bodies one from the other as the bodies move past a site of selection. More specifically, there is disclosed method and apparatus for selecting which of the needles carried within the tricks of the needle cylinders of rotary knitting machines are caused to knit or not to knit. In the device described, selection of the needles actually results, in the preferred arrangement, from the operation of magnet means including permanent and electromagnets upon edge portions of patterning or needle jacks located beneath the needles themselves, rather than by direct action upon the needles. The actuating or selecting mechanism generally comprises a first or lower magnet means that includes a pair of poles, one of which is shaped in such a fashion as to provide a cam surface against which one end (in this case, the lower end) of the jacks will be cammed into a preselected position. This preselected position is one in which the other ends of the jacks, here the upper ends, are moved into a select position where they can be magnetically engaged by a second or upper magnet means. The second magnet means includes a plurality of electromagnets, which in operation are sequentially energized, and permanent magnet means that serve to maintain the needle jacks in position for selection to the non-operative position and to maintain the jacks in the non-operative (non-knitting) position for a length of time sufficient to permit the jacks to clear the knitting cams located circumferentially about the periphery of the needle cylinder. |
