| 摘要 |
664,938. Making turbine blades. OESTRICH, H. April 12, 1949 [April 22, 1948], No. 9903/49. Class 83 (ii). [Also in Group XXVI] A hollow turbine blade (see Group XXVI) is produced from a sheet metal blank 15 which is folded so that the two longitudinal edges 10a, 10b form the trailing edge of the blade body, the edges being internally bevelled over the areas which in the finished blade are in contact with each other. The depth of the bevel diminishes gradually from the root towards the tip as shown at 20a, 20b. The thickness of the metal blank preferably decreases from the root towards the lip. The rectangular lugs 16, 17, 18, 19 are adapted to form a bulb type of blade root, Fig. 3. The blade blanks may be produced in a rolling mill the rolls of which have been machined to give the desired section. A tube-shaped member may be used as a blank which is then pressed, stamped or drawn to the desired blade shape. |
