Method of and apparatus for feeding nonround-section bars to screw machines

DETAILED DESCRIPTION What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.
1.
A method of feeding an elongated profiled bar to a screw machine having a headstock whose collet has an openable aperture that complements the cross-sectional shape of said bar and wherein the collet is closed on said bar and driven at a relatively high rotational speed during machining, said method comprising the steps of: holding said collet open; detecting the rotational speed of said collet and generating a speed output only when said rotational speed lies within a predetermined relatively low-speed range; pushing said bar longitudinally forwardly toward said collet only in response to generation of said speed output, whereby when the open aperture and said bar align the latter can pass forwardly through the former; and closing said collet on said bar only after passing of same forwardly through said aperture.
2.
The method defined in claim 1, further comprising the steps prior to pushing of said bar forwardly of: advancing said bar to a position immediately adjacent said collet, and thereafter inhibiting further advance of said bar until said speed output is generated.
3.
A method of feeding an elongated profiled bar to a screw machine having a headstock whose collet has an openable aperture that complements the cross-sectional shape of the bar and wherein the collet is closed on the bar and driven at a relatively high rotational speed during machining of the bar, said method comprising the steps of: a.
detecting the rotational speed of said collet and generating a speed output only when said rotational speed lies within a predetermined range; b.
holding said aperture open and pushing the bar forwardly longitudinally toward said collet only in response to generation of said speed output, whereby the bar and said aperture are aligned the former can pass forwardly through the latter; c.
closing said collet on the bar only when same has passed forwardly through said aperture; d