TOOL POSITIONING AND RAPID RETURN DEVICE OF ORDINARY LATHE

摘要

PURPOSE:To make possible working, particularly thread-rolling without using any intricate mechanism by working the material by the tool on the tool rest which is slidable in the cross feed direction on the cross slide of an ordinary lathe, detecting the top dead point position upon completion of the working and rapidly returning the tool rest by springs. CONSTITUTION:A carriage 1 is positioned and stopped and the work is gripped with a chuck 47. While the work is being rotated, a cross slide 3 is fed in the A direction. The pawl 21 of a slide bed 4 is engaged with the recess 24 of the locking plate 14 secured to a tool rest 8 and the rest 8 moves together with the bed 4 in the A direction against the springs 42 with a stationary member 13. The thread rolling head 7 on the rest 8 is pressed to the work, whereby the work is rolled. At this time, a pawl control plate 18 is held secured and static to the member 13 and therefore a pin 25 moves in the A direction while making slide contact with a surface 26. When the head 7 comes to the top dead point, the pin 25 is moved by the cam surface 27 of the plate 18 and the pawl 21 is gradually disengaged from the recess. Further, when the vertex of the triangle protrusion 28 of the engaging plate 29 of the pawl passes the vertex 31 of the engaging part 31 of a pawl locking member 32, the engagement of the pawl 21 is quickly removed by the sping 33 force and the rest 8 is returned in the B direction by the spring 42 force.