GB447082A - Improvements in or relating to apparatus for the control of machine tools by photo-cells - Google Patents

Abstract

447,082. Milling helical surfaces. COLLET & EN GEL HARD WERKZEUGMASCHINENFABRIK AKT.-GES., 130, Bernardstrasse, Offenbach-on-Main, Germany. Jan. 4, 1935, No. 381. Convention date, Feb. 12, 1934. [Class 83 (iii)] [See also Group XXXVIII] In a system for automatically controlling the movements of a machine tool in accordance with graphic presentations drawn on a record band, the movements are controlled by photo - electric cells which co-operate with the record. As shown, the apparatus is used for machining a propeller 3. The propeller is mounted on a table 1 rotatable by a motor 8 and is worked by a rotary cutter 13 which is movable vertically by a motor 16. The motors 8, 16 operate screwed spindles 9, 18 carrying photo-electric cells 11, 22 which are movable transversely across a record band 24 driven by a motor 27. The cell 11 co-operates with graphic records 28, 28a, 28<b> which control the oscillatory motion of the table 1, the arrangement being such that the cell 11 is driven to follow the records. The cell 22, which is mounted on a motor-driven pulley 23 and is radially adjustable in accordance with the size of the cutter 13 co-operates in a similar manner with record lines 29, 29<a>, 29b which form representations of the contour of the various sections of the propeller. Each record line shown corresponds to one half of a contour line and arrangements are made, through the intermediary of markings 30, 30<a>, 30<b> and a third cell 20, to effect reversal of motion of the cell 22 relatively to the record lines when passing from one line to the next. The cell 22 and the lines 29, 29<a>, 29<b>, &c. therefore control the vertical movement of the cutter 13. This vertical movement in conjunction with the oscillatory motion of the table is effective to produce a section of propeller which corresponds to the graphic record on the band 24. In order to ensure the same expenditure of power at a constant speed of the cutter, the oscillatory speed of the table may be controlled by providing lines 28, 28<a>, &c., the inclinations of which progressively decrease.