Premi per ingrandire
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Description
When shaft A rotates, roller 3 is rolled around fixed cam 4 by means of feed crank 1 and link 2. As roller 3 drops into low places a and d of cam 4, pawl 5, carried by link 2, engages the teeth of ratchet wheel 6. This turns feed roll 7 which is rigidly attached to ratchet wheel 6. Roll 7 and wheel 6 rotate freely on shaft A. Roll 7 feeds a definite length of wire 8 to the cutting-off shear. As roller 3 engages high parts b and e of cam 4, link 2 is pushed outward and pawl 5 is disengaged from the ratchet wheel. At this, feed roll 7 stops together with the feeding motion of the wire. Idler roll 9, by means of spring 10, exerts pressure on wire 8 against roll 7 required to provide the necessary traction to feed the wire. Spring 11 holds roller 3 against cam 4. $3353$CR,SF$
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