Fluid reaction surfaces (i.e. – impellers) – Having positive means for impeller adjustment – Motor bodily rotatable with impeller hub or shaft
Reexamination Certificate
2000-06-20
2002-01-22
Look, Edward K. (Department: 3745)
Fluid reaction surfaces (i.e., impellers)
Having positive means for impeller adjustment
Motor bodily rotatable with impeller hub or shaft
C416S158000, C416S22300B
Reexamination Certificate
active
06340290
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is generally related to controllable pitch propellers and, more specifically, to a controllable pitch propeller that automatically changes the pitch of the propeller blades to an increased pitch position in the event that the propeller blade actuator fails, such as because of a mechanical fracture or the failure of a hydraulic actuation system.
2. Description of the Prior Art
Four basic types of marine propellers are known to those skilled in the art. Some propellers have blades that are integral with the propeller hub and which are disposed at fixed pitch positions relative to the propeller hub. Other propellers allow the pitch of the propeller blades to be adjusted manually by manually detaching the blades from the propeller hub and then manually reattaching the blades to the propeller hub at a desired pitch position. Some propellers are configured to automatically change their pitch in response to hydrodynamic and/or centrifugal forces during operation of the propeller. Other propellers, which are referred to herein as controllable variable pitch propellers, are controlled through the use of mechanical or hydraulic systems so that the pitch of the blade can be changed under the command of a remote controller, such as a microprocessor.
Various types of controllable pitch propellers are known to those skilled in the art. An external controller can provide signals to a hydraulic, mechanical, or electrical actuation system in order to selectively change the pitch of the propeller blades during operation. Typically, the controller senses various parameters relating to an engine of a marine vessel and speed of the vessel to determine a desirable pitch setting for the blades of a propeller. Commands are then provided to the actuation system which physically moves the propeller blades relative to the propeller hub to achieve the desired pitch angle.
U.S. Pat. No. 3,801,219, which issued to Parsons et al on Apr. 2, 1974, describes a controllable pitch marine propeller. It comprises a hub which has a one piece casting mounting the blade spindles, irreversible pitch controll mechanism, and a rotary motor control and gear reducer. Although low in weight and small in overall size, precise control over blade angles is maintained and wear is minimized.
U.S. Pat. No. 4,897,056, which issued to Muller on Jan. 30, 1990, describes a propeller for a water vehicle. The variable pitch propeller is fixed to a guide body pivotable about an axis and can be raised above the water surface by its pivoting about the axis. An adjusting device jointly rotating with the hub of the variable pitch propeller and positioned on that hub can be set or adjusted without difficulty by a rotatable handle to adjust the pitch of the propeller blades in accordance with the intended travel mode, whereby a detectable fuel saving can be achieved.
U.S. Pat. No. 5,967,750, which issued to Elliott on Oct. 19, 1999, describes a variable pitch marine propeller. The propeller system has a propeller unit for mounting on a driveshaft, and a power unit including a stationary annular hydraulic cylinder for operating the propeller unit, a hydraulic remote control unit being fluid coupled to the power unit. An annular piston of the hydraulic cylinder is coupled to a ring-shaped actuator yoke by a roller thrust bearing, the actuator yoke axially displacing a mating yoke of the propeller unit with which the actuator yoke is allowed to rotate. The piston operates in a sealed environment for exclusion of water from the separately sealed surfaces of the cylinder itself. In one configuration, the propeller unit is displaced without disturbing the sealed environment of the annular piston. The control includes a hydraulic controlled cylinder that is operated by a rotatably mounted barrel that engages a threaded piston rod. Alternatively, the control cylinder is actuated by a lever having biasing springs and an adjustable brake.
U.S. Pat. No. 3,794,441, which issued to Johnson on Feb. 26, 1974, describes a variable pitch propeller. It particularly pertains to a means whereby the blade pitch in a propeller may be varied by employing unidirectional rotation of a propeller shaft, a portion of the power driving the propeller, and a pair of braking means. A propeller hub having a plurality of pivotally mounted blades is mounted on the propeller shaft. A blade pitch actuator member having a hub end and a brake end extends through the propeller shaft into the propeller hub. An eccentric slider block secured to the hub end of the actuator member is interconnected to each of the propeller blades. An actuator gear is screw mounted on the brake end of the actuator member. Three pairs of planetary pinions, each pair secured to a common shaft, are mounted on the propeller shaft in substantially parallel spaced relation to the axis of rotation of the propeller shaft. One of each pair of planetary pinions is meshed with the actuator gear and further meshed with an outer sun gear secured to a first brake actuated member. The other of each pair of planetary pinions is meshed with an inner sun gear secured to a secondary brake actuated member. Each brake actuated member has a brake actuator means. Application of the first brake means causes the actuator gear to rotate in one direction and application of the second brake means causes the actuator gear to rotate in the other direction. Rotation of the screw mounted actuator causes movement of the actuator member and eccentric slider block, thus altering the propeller blade pitch.
U.S. Pat. No. 3,972,646, which issued to Brown et al on Aug. 3, 1976, describes a propeller blade structure and method particularly adapted for marine ducted reversible thrusters and the like for minimizing cavitation and related noise. The blade design is concerned with reducing blade generated cavitation and accompanying noise in systems such as marine ducted reversible thrusters and the like, by novel techniques including a skew-forward blade configuration at the outer radii and particular blade thickness/chord length ratios associated therewith.
U.S. Pat. No. 5,997,253, which issued to Feehan on Dec. 7, 1999, discloses an adjustable pitch propeller which is provided with a receptacle on its hub which is shaped to receive a base portion of a propeller blade. First and second pluralities of alignment devices are provided to allow an operator to select a desired pitch angle and attach the blades of the propeller to the hub so that the desired pitch angle is selected. Alignment devices can comprise a plurality of holes in each receptacle which are tapped to receive a bolt in threaded association therein. Associated holes in the base portion of the propeller can allow free passage of the bolt by selecting one of the holes in the base portion of the propeller and aligning that hole with an associated hole in the receptacle of the hub. An operator can quickly and easily select a desired pitch angle for the blade. A bolt passes through a hole in the base portion of the blade and threads into the associated hole in the propeller hub to select the pitch and attach the base portion to the hub.
U.S. Pat. No. 4,792,279, which issued to Bergeron on Dec. 20, 1988, describes a variable pitch propeller. The automatic variable pitch propeller comprises a central hub defining an axis of propeller rotation and a plurality of blades connected to and extending from the central hub substantially normal to the axis of rotation. Each blade is mounted for rotation about a pitch axis. Means is provided to translate outward movement of that blade resulting from centrifugal forces imposed on that blade by rotation of the propeller into a force tending to rotate that blade about its pitch axis toward a feathered pitch condition. The force is opposed by a feathering force acting at a center pressure of the blade offset from the pitch axis. It is caused by resistance to rotation of the propeller and tends to decrease blade pitch toward a feathered condition.
U.S. Pat. No. 5,326,223, whic
Koepsel Roger E.
Schott Carl G.
Brunswick Corporation
Lanyi William D.
Look Edward K.
Nguyen Ninh
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