| 摘要 |
<p>424,658. Screw - propellers. LAWRINSON, A., 33, Wilderspool Causeway, Warrington, Lancashire. Sept. 21, 1933, No. 26083. [Class 114] A screw propeller comprises three or more blades d cast on a boss b and arranged symmetrically therearound, the blades d are flat, substantially circular discs, and are sharpened around their edges so as to cut weeds. The line of intersection of each blade with the surface of the boss extends over an angle of substantially 180‹ so that the blades overlap when viewed in the direction of the axis of the boss.</p> |
