Patent Number: 6,425,788

Title: Controllable-pitch propeller

Abstract: The invention relates to a propeller suited for installation in boats and vessels and having a run-time controllable pitch of propeller blades (4). The propeller comprises a hollow hub casing (2) containing a sleeve (10) adaptable about the propeller shaft (3) and adapted to rotate along with the propeller shaft (3), a fixed stator (6) adapted about said sleeve (10) and including pressurized-medium spaces (11, 12) connectable to a pump (9), at least one double-acting servomotor adapted into the interior of said hub casing (2) for altering the pitch of said propeller blades (4), said servomotor being adapted to rotate with said propeller shaft (3), ports (14, 20; 15, 19) adapted to said sleeve (10) for transmission of a pressurized fluid between said pressurized fluid spaces (11, 12) and said servomotor, and a valve (28) connected to the ports (14, 20; 15, 19) and adapted to lock the pitch of said propeller blades (4) to a fixed pitch by way of preventing the flow of said pressurized medium from said pressurized-medium space (11, 12) to said servomotor and, respectively, out from said servomotor to said pressurized medium space (11, 12) when the pressure in said pressurized-medium space (11, 12) falls below a certain level.

Inventors: Lindholm; Jan-Erik (Vasterskog, FI)

Assignee: AB R & D Marine OY

International Classification: B63H 3/00 (20060101); B63H 3/08 (20060101); B63H 003/00 ()

Expiration Date: 07/30/2019