GB1152253A - Thread Cutting Device - Google Patents

Abstract

1,152,253. Thread cutting. P. L. GLOCKER. 5 Aug., 1966 [9 Aug., 1965], No. 35118/66. Headings B3B and B3T. In a lathe incorporating a thread cutting device a thread cutting tool 8 is mounted on the lathe cross slide 6 which in turn is mounted on a longitudinal slide 5 and an auxiliary tool 16 for producing the endmost thread turn on a workpiece is mounted on the cross slide 6 by way of longitudinal and transverse carriages 14 and 10 respectively. Roller followers 28 and 22 mounted on respective carriages 14 and 10 are adapted to contact the respective radial and peripheral faces 30, 23 of a cam member 24 mounted on the lathe spindle 2, the followers 22, 28 being supported on carriages 10 and 14 respectively by lever means 18, 19 and 21 and 27, 29, and the carriages 10 and 14 are spring biased towards the work spindle. In operation, the cutting tool 8 is brought into position by the slides 5 and 6 together with the auxiliary tool 16, the rollers 22, 28 engage the cam faces on the member 24 and hence the position of the auxiliary tool, by the action of carriages 10 and 14, in respect to the cutting tool 8 and the workpiece 4 is varied. When the tool 8 has almost completed a thread on the workpiece the roller followers 22, 28 which have been pre-positioned permit the auxiliary tool to engage the last remaining portion of the thread on the workpiece by moving the carriages in response to the profiles of the cam 24 and the cutting action of the auxiliary tool then produces a predetermined machined lead on the first turn of the thread produced by the tool 8. The action of the cutting tool 8 being effected by cams actuating the main slides 5 and 6 in a known manner. The path followed by the auxiliary tool is determined by the profiles on the cam member 24 and by the proportional pivoting action between the levers 21, 29.