GB883847A - Mechanical low pitch stop of a variable-pitch propeller - Google Patents

Abstract

883,847. Variable pitch propellers. GENERAL MOTORS CORPORATION. May 18, 1960 [June 17, 1959], No. 17525/60. Class 114. A mechanical low pitch stop assembly of variable pitch propeller includes a master gear 18 rotatably supported within the hub 10 and meshing with bevel gear sectors 16 on the propeller blades 14 so as to rotate about the propeller axis during pitch changing movement of the blades, a first annulus 30 attached to said gear 18 via a splined sleeve 26, a second annulus 48 splined at 50 to a housing 22 secured to the hub 10 so as to be restrained against rotation relative to the hub but capable of axial movement relative thereto, the two annuli having circumferentially spaced axially extending jaws with engageable faces, the jaws 32 of one annulus having caged rollers in their faces, and springs 64 engaging the second annulus 48 for maintaining it in engagement with the first annulus 30 to prevent rotation of the latter and movements of the blades below a predetermined pitch angle, the second annulus 48 having a piston surface 58 which can be subjected to hydraulic pressure in a space 74 for moving said annulus 48 out of engagemen with the first annulus 30 to permit rotation o the latter and movement of the blades below the predetermined pitch angle, the caged roller facilitating disengagement of the jaws of th annuli under load without damaging th faces of the jaws.