| 摘要 |
460,791. Electric control systems. SIEMENS - SCHUCKERTWERKE AKT.- GES. Sept. 30, 1935, No. 26987. Convention date, Oct. 2, 1934. [Class 40 (i)] In a feeler control device for controlling the feed motions between the cutter and work in machine tools, and particularly adaptable for copying-lathes and copying milling-machines a nozzle bolometer of known form is operated by the feeler and is utilized to produce electric control impulses for controlling the feed motions. As applied to a copying-lathe or milling-machine, the feeler 1 which contacts with the pattern is mounted by means of a semi-spherical part 2 in a casing 3 attached to a base 19 which may be secured to the sliderest &c. of the machine. A ball 4 at the rear end of the feeler engages a spherical recess 5 in a lever 20 pivoted at 6 on a bracket 21 secured to the base 19. A second arm 10 on the lever 20 carries a shutter 11 for co-operating with two nozzles 12, 13 of a nozzle bolometer, which consists of two heated branches of a temperature-sensitive electric bridge circuit which are normally cooled by two currents of air from the nozzles, the air currents being of equal amount in the neutral or zero condition of the apparatus. Oscillation of the lever 20 by pressure of the pattern on the feeler causes the shutter 11 to obstruct one or other of the nozzles by a variable amount, thus cutting down one of the air currents and varying the resistance of the corresponding branch of the bridge. The electric impulses so produced are used to operate an electric discharge rectifier having one or more control electrodes, which in turn controls the feed mechanism, such as magnetic couplings. A spring 8 biasses the lever 20 in a clockwise direction and stops 15, 16 limit the movements of the shutter 11. Damping means for the control may be provided to reduce the frequency with which changes of feed are effected. The arm 10 and shutter may be adjusted relatively to the lever 20 by means of a slot and screw 18. |
