| 摘要 |
369,226. Milling screw propellers. G E B E R S, F., 256, Brigittenauerlõnde, Vienna. Dec. 16, 1930, No. 37910. Convention date, Jan. 21. [Class 83 (iii).] In a method of milling the surfaces of screw propellers, a milling cutter 1, Figs. 7 and 4, rotating in a plane containing a generator 2 of the propeller surface is fed in a direction parallel to the -propeller axis while the propeller is simultaneously rotated to produce a cut 6 on the work. The cutter is fed radially along the propeller blade between successive cuts, the ridges 7 left on the work being subsequently removed by hand. The cutter is driven by gearing from a motor 14 and is mounted on a slide 15 which may be operated to feed the cutter radially of the work. The slide is carried by a turntable 16 which may be angularly adjusted for cutting propellers having inclined blades. The carriage 9 supporting the cutter slide carries a roller 9a and is urged by a weight 17 against a pitch ruler 11 carried by a table 10 which may be traversed along guide-rails by means of a screw 18. The table 10 carries a rack 20 engaging a toothed segment on an arm 21 secured through an angularly-adjustable coupling 22 to the propeller shaft 13. Thus in operation, as the table 10 is moved forward, the pitch ruler causes the milling cutter to be fed forward in the direction of the propeller axis while at the same time the propeller is rotated at the rerequired speed by the sector 21. The apparatus can also be used for milling the back surface of the propeller, a curved guiding-ruler being employed and the milling-cutter being placed in the position shown at 1<1> in Fig. 7. Curved guiding-rulers, such as adjustable flexible steel members, may also be used for milling propeller surfaces of variable pitch. |
