GB561041A - Improvements in or relating to lathes - Google Patents

Abstract

561,041. Lathes. AKT.-GES. DER EISEN-UND STAHLWERKE VORM. G. FISCHER. Feb. 17, 1943, No. 2655. Convention date, Dec. 23, 1941. [Class 83 (iii)] In a lathe particularly for turning work-pieces 11, Fig. 1, having parts of different diameters connected by radial shoulders the tool 9 is carried in an inclined cross slide 10 actuated by a hydraulic cylinder under control of a feeler 26 engaging a templet so that when the feeler engages the shoulder 30 of the templet the cross slide is automatically retracted while still partaking of the longitudinal movement, the resultant movement being such that the tool faces the radial shoulder and resumes its longitudinal traverse when the feeler passes off the templet shoulder. The longitudinal carriage 2 is actuated from an electric motor 3 secured to the carriage and driving through worm gearing 4 a pinion 5 engaging a rack 6 fixed to the frame. The carriage has a guide plate 8 pivoted at 7 and provided with a bracket 17 carrying a relatively fixed hollow piston rod 16 and piston 15 working in a cylinder 14 formed in the cross slide 10. The work is mounted above the tool slides between a headstock 12 and tailstock 13. A pump 19 supplies fluid through the piston rod 16 to the cylinder 14 and a valve 22 controls flow through a by-pass 23 to the lower end of the cylinder whence fluid flows to the tank through a throttled pipe 24. Valve 22 is actuated by a lever 26 coacting with the fixed templet 27 profiled with one or more steps or shoulders 30 corresponding with the work to be turned. In operation the hydraulic pressure in the upper part, Fig. 2, of cylinder 14 moves the cross slide up to the work until lever 26 engages the templet whereupon the valve 22 is opened and the pressure by-passed. This causes the tool to retract slightly and closes the by-pass. The tool moves along the work until the feeler engages the shoulder 30. This opens the valve 22 and as long as this engagement is maintained the cross slide is withdrawn while the. longitudinal movement continues so that the resultant movement of the tool is perpendicular to the lathe axis. The longitudinal traverse is resumed when the feeler clears the part 30 of the templet. By moving the cross slide to the dotted position, Fig. 1, shoulders facing in the opposite direction may be turned. In a modification, Fig. 3, two tool slides one above and one below the work are controlled respectively,.by templets 40, 37 in a manner similar to that described above. By moving one of the cross slides to the dotted line position both tools may be moved over the same part of the work, one taking a roughing and the other a finishing cut. In another modification several carriages may be arranged on the same slide, the tool rests being individually controlled. The invention is also applicable to vertical lathes. The Specification as open to inspection under Sect. 91 describes also a modification, Fig. 5 (Cancelled) wherein an adjustable stop arm 43 is provided so that where a considerable reduction in work diameter is to be effected the stop arm may be set to take successive roughing cuts 44<1>, 44<11>. This subject-matter does not appear in the Specification as accepted.