Abstract: A self-actuating variable pitch marine propeller which incorporates two or more blades which are rotatably connected to a central hub; the blades rotate relative to the hub center about the shank axis. In operation, the blades are biassed towards the lower pitch, both by mechanical means, such as a spring, and optionally also by hydrodynamic load means. As the propeller rotational speed increases, centrifugal forces act to move the blades towards the higher pitch position. In one alternative mode the hydrodynamic load also acts towards the higher pitch position. There is further provided a holding mechanism to retain or hold the blades at least preferably in the lower pitch position, the holding mechanism being so designed that at a sharply defined combination of parameters, including rotational speed and optimally hydrodynamic load acting on the blades, the holding mechanism is caused to be released and the blades permitted to move to a second higher pitch position.

Abstract: There is provided a self-actuating variable pitch marine propeller which incorporates two or more blades, each independently rotatable, relative to the propeller hub, between a first lower and a second higher pitch. The blades are preferably mechanically linked by coordinating means and are caused to move preferably by a combination of centrifugal force effect resulting from inertial mass means and the hydrodynamic forces acting upon the blade hydrodynamic surface. The rotation of the blades relative to the propeller hub is limited primarily as to speed of rotation by restricted viscous fluid flow damping means operably connected to the blades. In one preferred embodiment, the viscous flow means further acts as an initial restraint against all motion by closing off the viscous flow orifice until a certain minimum propeller rotational speed is achieved.

Abstract: A self-actuating variable pitch marine propeller which incorporates two or more blades having cylindrical shafts which are rotatably connected to a central hub via cylindrical joints; the blades rotate about and translate radially, relative to the hub center, along the blade shaft, or shank, axis. In operation, the blades move radially outwardly from the hub center as they rotate from lower to higher pitch. The blades are biased towards the lower pitch. As the propeller rotational speed increases, centrifugal forces act on the blade mass creating a radially directed outward force. This radially outward force, upon reaching a sufficient magnitude, causes the blades to move radially outward. A blade positioning mechanism connected between each blade and the hub directs the blades to rotate to a higher pitch angle as the blades move radially outward.

Abstract: There is provided a self-actuating, variable pitch propeller having a plurality of blades. All of the blades are automatically movable between a first, relatively lower pitch position and a second, relatively higher pitch position, substantially simultaneously and equally in response to achieving a predetermined combination of propeller rotational speed and hydrodynamic loading on the propeller blades. The blades are releasably locked to prevent pivoting of the blades, at least in the lower pitch position, but preferably can be locked in both the high and low pitch positions. More preferably, a feedback force is transmitted from the blade to the locking mechanism to vary the locking force in response to the net turning moment on the blade. The locking mechanism are released in response to the combined effects of centrifugal force generated by the blades and other portions of the propeller and the hydrodynamic loading on the blades.

Abstract: There is provided a self-actuating, variable pitch propeller having a plurality of blades. All of the blades are automatically movable between a first, relatively lower pitch position and a second, relatively higher pitch position, substantially simultaneously and equally in response to achieving a predetermined combination of propeller rotational speed and hydrodynamic loading on the propeller blades. The blades are releasably locked to prevent the pivoting of each blade when in the locked position. The locking means are released by actuating means activated by the combined effects of centrifugal force and hydrodynamic loading.