| 摘要 |
506,241. Making propeller blades ; lathes. RATIE, P. J. P. Aug. 12, 1938, No. 23878. [Class 83 (iii)] In a copying-machine particularly for making propeller blades the pattern blade 3 and the blanks 4 to be cut are arranged at the corners of a regular polygon such as a square, Fig. 1, while the tracing roller 20 and its associated milling-cutters 21 are arranged at the corners of a similar polygon having the same centre so as to constitute an angularly movable unit which is balanced in all positions. The chucks 2 for the pattern and blades are carried in a pair of headstocks], the chucks of both headstocks being driven synchronously from a central driving shaft 5 and one headstock being longitudinally adjustable along the key 6. A support 7 carries on ball bearings a hub 8 and a driving pulley 9, both concentrically mounted over the shaft 5. The hub carries a member 12 on which are mounted arms 14 which are individually adjustable by gears 18 engaging teeth on the curved tongue positions 17 of the arms. After adjustment the arms are locked by screws 15. The milling cutters are driven by belts'passing over pulleys 23 ... 25 and round one of the grooves of the pulley 9 which is itself driven by belt 26 from a motor 28. An adjustable counterweight 29 maintains the tracer roller in contact with the pattern. In operation the pattern and blanks are rotated synchronously in the direction of arrows 3k, 4k, and the support 7 together with the motor 28 is moved longitudinally along the blades. In a modification the support 7 may be fixed and the blades moved longitudinally. |
