| 摘要 |
A device for selectively lifting a multiplicity of needles which are mounted to an upstanding, rotatable cylinder for up and down sliding motion. Each needle has a shank with two butts formed in vertically spaced positions thereon, so that there are formed tow rows of such butts extending circumferentially of the cylinder. The upper one, for example, of the two rows of butts includes a group of butts that are longer than the other butts of the same row. Slidably supported adjacent the cylinder are a pair of cams which are independently moved, as by solenoids, toward and away from the cylinder and which have sloping cam surfaces for relatively sliding engagement with the respective rows of butts when the cams are thrusted toward the cylinder in rotation. The vertical distance between the sloping surfaces of the two cams is so determined in relation to that of the butts on each needle shank that when the upper cam is first moved toward the cylinder for lifting the needles having the longer butts by making relatively sliding contact therewith, the other cam can be subsequently moved toward the cylinder without being loaded by the lower butts of the needles being raised. Then, as the longer upper butts ride off the upper cam, the following needles will be raised as their lower butts ride onto the lower cam.
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