Marine propeller with removable blades

Claim 2

In a marine propeller assembly having a plurality of blades, each of which is removably mounted on a hub at a blade position, the hub and blades having complementary engaging portions, the engaging portion of each blade being a flange part at its root and the hub having a blade-engaging portion at each blade position, the improvement of a device for urging each blade away from the hub for removal therefrom comprising fluid-actuated piston means associated with each blade and within the propeller assembly for displacing the associated blade generally radially outward relative to the axis of rotation of the propeller, and means for communicating actuating fluid to the piston means from a location externally of the assembly, the piston means including a cylinder in one of said complementary engaging portions at each blade position, a piston in the cylinder, and a piston extension part on the piston and movable upon fluid actuation into engagement with the other of said complementary engaging portions at each blade position.

Claim 3

An improvement according to claim 1 wherein the cylinder of the piston means for each blade is located in the blade, and the piston extension part on the piston is movable upon fluid actuation into engagement with the hub at the corresponding blade position.

Claim 4

An improvement according to claim 1 further comprising resilient return means for restraining each piston against the movement thereof tending to displace the corresponding blade outwardly.

Claim 5

An improvement according to claim 1 wherein the blade is located on the hub for pivoting relative to the hub about an axis lying substantially in a radial-axial plane of the propeller, and wherein each piston means is positioned to act at and along the pivot axis of the associated blades.

Claim 6

In a marine propeller assembly having a plurality of blades, each of which is removably mounted on a hub and has a flange portion at its root for engagement at a blade position with the hub, the improvement of a device for urging each blade away from the hub for removal therefrom comprising in association with each blade an inwardly open cylinder formed in the blade flange, a piston received in the cylinder in sealing and sliding engagement with the cylinder walls and having an extension portion associated with it and located to engage a portion of the propeller hub at the corresponding blade position, resilient means for urging the piston away from the hub, and a passage through the blade flange communicating with a head part of the cylinder that is on the opposite side of the piston from the hub and leading to the exterior of the blade flange thereby to enable a fluid under pressure to be introduced into said head part of the cylinder and generate a force on the piston effective to urge it toward the hub and to engage the piston extension portion with the hub and to generate a force acting at the head of the cylinder and effective to remove the blade away from the hub.

Claim 7

In a marine propeller assembly having a plurality of blades, each of which is removably mounted on a hub and has a flange portion at its root for engagement at a blade position with the hub, the improvement of a device for urging each blade away from the hub for removal therefrom comprising in association with each blade an inwardly open cylinder formed in the blade flange, a piston received in the cylinder in sealing and sliding engagement with the cylinder walls and having an extension portion associated with it and located to engage a portion of the propeller hub at the corresponding blade position, resilient means for urging the piston away from the hub, and a passage through the blade flange communicating with a head part of the cylinder that is on the opposite side of the piston from the hub and leading to the exterior of the blade flange thereby to enable a fluid under pressure to be introduced into said head part of the cylinder and generate a force on the piston effective to urge it toward the hub and to engage the piston extension portion with the hub and to generate a force acting at the head of the cylinder and effective to remove the blade away from the hub.