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All the working mechanisms of the machine - the headstock on the right, the d rilling and threading attachments on the l eft, and the tool head in the side of the bed and carries cams which control the headstock feed, the feeds of the uppe r tool slide, the rocker, the spindles of the drilling and othe r attachments , and the closing and releasing of the collet. The camshaft is driven by the trans vers e s haft VII, mounted inside the bed (Figure 6 ). A two-step pulley turns freely on one end of this shaft while a handle is fixed to its other end by m eans of which the camshaft can be m anually rotated when the machine is being adjusted. The worm, with s imple jaw clutches at both end s , turns freely on the transvers e shaft. The cam shaft is rotated by the pulley when the worm clutch engages the latter, and m anually when the worm engages the trans vers e s haft. T h e h e a d s t o c k (Figure 7 ) consists of a cast-iron body, inside of which the hollow spindle ( 1 ) is mounted in two bearings . The frontal bear ing is a bronze bushing (2 ), and the rear bearings are two radial- thrust bearings of the A accu racy clas s . The bar b eing machined passes inside the spindle and is clamped by the collet (3 ). The pulley (4 ) , rotated from the main drive s haft, is fixed on the spindle between the bearings . FrGURE 7 . Headstock The headstock moves longitudinally during the operation of the machine, and therefore the b elt als o m oves along the wide pulley of the main drive The collet mechanis m is mounted on the spindle (1 ). If the slider (5 ) is moved to the right, the front ends of the cams ( 6 ) are forced apart. The cam s , rotating on their axes, press the hardened bushing ( 7 ) forward. The bushing (7 ), by moving fo rward inside the spindle , applies pressure on the collet ( 3 ) through the tubes (8 ) and (9), thereby closing the collet. The onto the front end of the spindle. If the slider ( 5 ) is moved to the left, the forward ends of the cams ( 6 ) are able to be drawn together by the spring ( 1 0 ), and the bushing ( 7 ) retreats , releas ing the collet ( 3 ) . 1 0 5 |