| 摘要 |
<p>352,833. Screw propellers. CALLAHAN, J. J., Holy Ghost Cottage, Cornwells Heights, Pennsylvania, U.S.A. Oct. 4, 1930, No. 29751. [Class 114.] In a screw propeller of the type in which the rear portion of the active face of the blades forms an abrupt angle with the rest the rear face is given an increasing pitch angle from root to tip such increase being at a greater rate than that at the driving face. The active side of the blade 12 comprises a screw propeller face 14 and a compresser face 15, the free edge 16 constituting the leading edge. A line joining the leading edge 16 with the following edge 17 is approximately 45‹ to the plane of rotation. The rear face 18 is substantially straight but curves in at 19 toward the following edge.</p> |
