# US 8,465,257 B1 · Variable pitch propeller > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,465,257 B1 - Document ID: US8465257B1 - Status: Granted - Kind: B1 - Application number: 12/609,511 - Filed: 2009-10-30 - Granted: 2013-06-18 - Earliest claimed: 2008-10-31 - Assignees: BRP US Inc. - Applicants: Mark C. Noble; Richard McChesney; Laverne Tatge; Dave Calamia; Gerald Ewens; Rudolf Wendler; Simon Pfiffner - Inventors: Mark C. Noble; Richard McChesney; Laverne Tatge; Dave Calamia; Gerald Ewens; Rudolf Wendler; Simon Pfiffner - Web page: https://patentgrep.com/patent/US8465257B1 ## CPC - B63H 3/008: {characterised by self-adjusting pitch, e.g. by means of springs, centrifugal forces, hydrodynamic forces} - B63H: MARINE PROPULSION OR STEERING (propulsion of air-cushion vehicles B60V1/14; specially adapted for submarines, other than nuclear propulsion, B63G; specially adapted for torpedoes F42B19/00) ## Abstract A propeller assembly is disclosed, comprising propeller blades pivotably mounted on a propeller hub. A cam follower is disposed on each propeller blade. A cam is movable between a first position, a second position and a third position. Recesses formed in the cam have a first segment, a second segment and a third segment, oriented at first, second and third angles. The first segment is oriented at a first angle relative to the central axis. The cam followers engage the first segment of the recesses when the cam moves between first and second positions to vary the pitch of the propeller blades between a first pitch and a second pitch. The cam followers engage the second segment of the recesses when the cam moves between second and third positions to vary the pitch of the propeller blades between the second pitch and a third pitch. ## Claims ### Claim 1 A marine outboard engine, comprising: a cowling; an engine disposed in the cowling; a driveshaft disposed generally vertically, the driveshaft having a first end and a second end, the first end of the driveshaft being operatively connected to the engine; a gear case disposed generally below the engine; a propeller shaft disposed at least in part in the gear case, the propeller shaft having a propeller shaft axis oriented generally perpendicularly to the driveshaft, the propeller shaft being operatively connected to the second end of the driveshaft; an actuator disposed within the gear case, the actuator having a cam, the actuator being movable relative to the gear case between a first position, a second position and a third position, the second position being between the first position and the third position; at least one recess formed in the cam, each of the at least one recess lying generally in a corresponding plane parallel to the propeller shaft axis, each of the at least one recess having a first segment, a second segment and a third segment, the second segment being between the first segment and the third segment, the first segment being oriented at a first angle relative to the propeller shaft axis; the second segment being oriented at a second angle relative to the propeller shaft axis, the second angle being greater than the first angle; and the third segment being oriented at a third angle relative to the propeller shaft axis, the third angle being smaller than the second angle; a propeller hub mounted to the propeller shaft; and at least one propeller blade pivotably mounted on the propeller hub, the at least one propeller blade being pivotable with respect to the propeller hub about a corresponding pivot axis, each pivot axis being oriented generally perpendicularly to the propeller shaft axis; at least one cam follower disposed on a corresponding one of the at least one propeller blade and being adapted to engage a corresponding one of the at least one recess, the at least one cam follower engaging the first segment of its corresponding one of the at least one recess when the actuator moves between the first and second positions to vary a pitch of the at least one propeller blade between a first pitch and a second pitch, and the at least one cam follower engaging the second segment of its corresponding one of the at least one recess when the actuator moves between the second and third positions to vary the pitch of the at least one propeller blade between the second pitch and a third pitch. ### Claim 2 (depends on 1) The marine outboard engine of claim 1, wherein when the at least one cam follower engages the first segment of its corresponding one of the at least one recess, the pitch of the at least one propeller blade is such that operation of the marine outboard engine propels a watercraft in a forward direction when the propeller shaft is driven in a first direction. ### Claim 3 (depends on 2) The marine outboard engine of claim 2, wherein when the at least one cam follower engages at least a portion of the second segment of its corresponding one of the at least one recess, the pitch of the at least one propeller blade is such that operation of the marine outboard engine propels the watercraft in a reverse direction when the propeller shaft is driven in the first direction. ### Claim 4 (depends on 1) The marine outboard engine of claim 1, wherein: the at least one recess includes three recesses; the at least one propeller blade includes three propeller blades; and the at least one cam follower includes three cam followers. ### Claim 5 (depends on 1) The marine outboard engine of claim 1, wherein: the at least one recess includes four recesses; the at least one propeller blade includes four propeller blades; and the at least one cam follower includes four cam followers. ### Claim 6 (depends on 1) The marine outboard engine of claim 1, wherein: the first segment of each recess is disposed forwardly of the second segment of their respective recess. ### Claim 7 (depends on 1) The marine outboard engine of claim 1, wherein the actuator is disposed at least in part inside the propeller shaft. ### Claim 8 (depends on 1) The marine outboard engine of claim 1, wherein: the pitch of the at least one propeller blade varies between the first pitch and the second pitch at a first rate relative to a rate of movement of the actuator; and the pitch of the at least one propeller blade varies between the second pitch and the third pitch at a second rate relative to a rate of movement of the actuator; the second rate being greater than the first rate. ### Claim 9 (depends on 8) The marine outboard engine of claim 8, wherein the second rate is at least 5 times the first rate. ### Claim 10 (depends on 8) The marine outboard engine of claim 8, wherein the first rate is less than 1.0 degrees per 1 mm of movement of the actuator. ### Claim 11 (depends on 10) The marine outboard engine of claim 10, wherein the first rate is approximately 0.3 degrees per 1 mm of movement of the actuator. ### Claim 12 (depends on 8) The marine outboard engine of claim 8, wherein the second rate is greater than 1.0 degrees per 1 mm of movement of the actuator. ### Claim 13 (depends on 12) The marine outboard engine of claim 12, wherein the second rate is approximately 3 degrees per 1 mm of movement of the actuator. ### Claim 14 (depends on 13) The propeller assembly of claim 13, wherein: the first segment of each recess is disposed forwardly of the second segment of the respective recess. ### Claim 15 (depends on 13) The propeller assembly of claim 13, wherein: the pitch of the first and second propeller blades varies between the first pitch and the second pitch at a first rate relative to a rate of movement of the cam; and the pitch of the first and second propeller blades varies between the second pitch and the third pitch at a second rate relative to a rate of movement of the cam; the second rate being greater than the first rate. ### Claim 16 (depends on 15) The propeller assembly of claim 15, wherein the second rate is at least 5 times the first rate. ### Claim 17 (depends on 15) The marine outboard engine of claim 15, wherein the first rate is less than 1.0 degrees per 1 mm of movement of the cam. ### Claim 18 (depends on 17) The propeller assembly of claim 17, wherein the first rate is approximately 0.3 degrees per 1 mm of movement of the cam. ### Claim 19 (depends on 15) The marine outboard engine of claim 15, wherein the second rate is greater than 1.0 degrees per 1 mm of movement of the cam. ### Claim 20 (depends on 19) The propeller assembly of claim 19, wherein the second rate is approximately 3 degrees per 1 mm of movement of the cam. ### Claim 21 A propeller assembly, comprising: a propeller hub, at least one propeller blade pivotably mounted on the propeller hub, the at least one propeller blade being pivotable with respect to the propeller hub about a corresponding pivot axis, each pivot axis being oriented generally perpendicularly to a central axis of the propeller hub; at least one cam follower disposed on a corresponding one of the at least one propeller blade; a cam disposed at least in part inside the propeller hub, the cam being movable relative to the propeller hub along the central axis between a first position, a second position and a third position, the second position being between the first position and the third position; at least one recess formed in the cam, the at least one recess being adapted to receive a corresponding one of the at least one cam follower, each of the at least one recess lying generally in a corresponding plane parallel to the central axis, each of the at least one recess having a first segment, a second segment and a third segment, the second segment being between the first segment and the third segment, the first segment being oriented at a first angle relative to the central axis; the second segment being oriented at a second angle relative to the central axis, the second angle being greater than the first angle; and the third segment being oriented at a third angle relative to the central axis, the third angle being smaller than the second angle; the at least one can follower engaging the first segment of its corresponding one of the at least one recess when the cam moves between the first and second positions to vary a pitch of the at least one propeller blade between a first pitch and a second pitch, and the at least one cam follower engaging the second segment of its corresponding one of the at least one recess when the cam moves between the second and third positions to vary the pitch of the at last one propeller blade between the second pitch and a third pitch. ### Claim 22 (depends on 21) The propeller assembly of claim 21, wherein when the at least one cam follower engages the first segment of the respective one of the at least one recess, the pitch of the at least one propeller blade is such that rotation of the propeller assembly in a first direction provides thrust in a first thrust direction. ### Claim 23 (depends on 22) The propeller assembly of claim 22, wherein when the at least one cam follower engages at least a portion of the second segment of the respective recesses, the pitch of the at least one propeller blade is such that rotation of the propeller assembly in a first direction provides thrust in a second thrust direction opposite to the first thrust direction. ### Claim 24 (depends on 21) The propeller assembly of claim 21, wherein: the at least one recess includes three recesses; the at least one propeller blade includes three propeller blades; and the at least one cam follower includes three cam followers. ### Claim 25 (depends on 21) The propeller assembly of claim 21, wherein: the at least one recess includes four recesses; the at least one propeller blade includes four propeller blades; and the at least one cam follower includes four cam followers.