| 摘要 |
489,648. Screw propellers. UNITED AIRCRAFT CORPORATION. Jan. 28, 1937, No. 2525. Convention date, Jan. 28, 1936. [Class 114] Blades of aeronautical screw propellers are mounted on spiders having elongated arms adapted to yield within limits in all directions. Upon the propeller shaft 10 is mounted the boss 14 that carries a number of arms 22, the boss being secured in position on feathers 16 and by conical end pieces 18, 20. From this boss 14 project arms 22 which are graded in size radially so as to yield under normal stresses within permissible limits. Upon these arms 22 are mounted blades 24 the hollow portion 30 of which is provided with bearing sleeves 114, 118 and also with adjustable balance weights 32. On the lower end there are sleeves 56 which are adapted to contact at their bases with yieldable plates 78. The blades are secured in position by divided sleeves 34 which are flanged so as to provide seatings for the thrust races 48, the other race 50 being carried by a flanged extension 28 of the root. The two parts 36, 38 of the divided sleeve 34 are held by bolts 40 and the member 38 is provided with an opening through which may be passed an arm 104 carrying counterweights. Between the base of each root and the boss 14 is provided a two-part rubber cushion and this is formed with projections adapted to seat in corresponding recesses 74, 76 in the boss. The front of the boss carries a hydraulic piston and cylinder by which pitch changes are positively effected. |
