Fluid reaction surfaces (i.e. – impellers) – Method of operation
Reexamination Certificate
2000-11-22
2002-04-30
Look, Edward K. (Department: 3745)
Fluid reaction surfaces (i.e., impellers)
Method of operation
C416S027000, C416S030000, C416S035000
Reexamination Certificate
active
06379114
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is generally related to a method for selecting the pitch of a controllable pitch marine propeller and, more particularly, to a method for selecting the pitch of a controllable pitch propeller based on a magnitude of an input parameter which is used to select a desired magnitude of an engine operating characteristic as a function of the input parameter, after which the pitch of the controllable pitch marine propeller is selected as a function of changes in the magnitude of the engine operating characteristic.
2. Description of the Prior Art
Conventional propellers used in conjunction with planing watercraft often experience large changes in operating conditions throughout the range of boat speed at which they are operated. These changes in watercraft operating conditions, in turn, cause large variations in the propeller's torque characteristics as a function of engine speed. Unlike automobiles, watercraft typically do not have multi-speed transmissions that allow the load to be adjusted to match the power characteristics of an associated internal combustion engine, so the engine used in a watercraft must be able to accept many different load changes. In practice, it is typical that the propeller load variations seriously limits engine performance in many common situations, although these variations usually are not sufficient to actually stall or overspeed the engine. The fact that propeller load is different at different boat speeds implies that a propeller which is selected to give optimal performance on one boat speed will differ from another propeller that is chosen for optimal engine performance at a different boat speed. Therefore, performance compromises are inherent in choosing conventional propellers for a planing watercraft. In other words, a conventional propeller chosen for best high speed performance would typically compromise low speed acceleration, and vice versa.
U.S. Pat. No. 4,639,192, which issued to Harrell on Jan. 27, 1987, describes a propeller pitch controlling arrangement having a fuel economizing feature. The arrangement has a fuel economizer feature for use on marine vessels and has a mode selector valve operable to a normal mode and an economizer mode. In the economizer mode, a first pilot signal is transmitted to a path selector valve to establish a first flow path to a propeller pitch servomechanism. A second pilot signal is transmitted from a relay valve when the marine vessel speed drops below a predetermined value. The second pilot signal moves the path selector valve to a second position establishing a second flow path to the propeller pitch servomechanism. A first selected fluid pressure from a regulating valve arrangement mechanically linked to the engine fuel rack, is directed to the propeller pitch servomechanism when the first flow path is established. This first selected fluid path is proportional to the movement of the engine fuel rack. A second selected fluid pressure transmitted from a pitch control valve, is directed to the propeller pitch servomechanism when the second flow path is established.
U.S. Pat. No. 5,415,523, which issued to Muller on May 16, 1995, describes a control system for a variable pitch boat propeller. A marine drive is provided with a propeller that is rotatable about a drive axis and has a plurality of blades. The blades are pivotable about respective blade axes projecting generally radially from the drive axis and each blade is movable between a low pitch end position extending generally parallel to a plane perpendicular to the drive axis and a high pitch end position extending at a large acute angle to the plane.
U.S. Pat. No. 4,744,727, which issued to Muller on May 17, 1988, describes a controllable pitch propeller and watercraft drive. The propeller assembly has an inner housing attached to a main driveshaft, the housing having rails on the outer surface thereof. Modules carrying the propeller blades are mounted positively on the rails, with each module having a housing receiving a hub cylinder and bushings axially aligned at opposite sides thereof. Each pair of bushings receives an adjusting piston having an adjusting pin which engages a groove forming a control path in a propeller hub. Each blade is adjusted by a control lever which adjusts each adjusting piston through a mechanical linkage including an adjusting sleeve and a thrust bearing and flange. The hub is provided with open spaces formed between the inner and outer housings to create exhaust ducts through the hub.
U.S. Pat. No. 5,174,718, which issued to Lampeter et al on Dec. 29, 1992, describes a blade pitch change control system. The system is used for adjusting the pitch of a variable pitch propeller blade operatively connected for pitch change to a pitch change actuator piston. A pitch change control system is operatively connected to the pitch change actuator piston for selectively pressuring the pitch change actuator piston to effectuate a desired change in the pitch of the propeller blades.
U.S. Pat. No. 5,226,844, which issued to Muller on Jul. 13, 1993, describes an actuator for a variable pitch propeller. It describes a drive for a boat which has a propeller hub rotatable about a main axis extending in a normal travel direction, a plurality of blades projecting generally radially from the main axis of the hub, and each blade being pivotal so as to be of variable pitch, with respective blade rods extending axially and displaceable axially relative to the hub to vary the pitch of the blades. A stator carried on the boat downstream in the direction from the hub and nonrotatable about the axis rotatably supports a cylinder housing that is releasably connected to the rods for joint axial movement therewith.
U.S. Pat. No. 4,347,039, which issued to Houghton on Aug. 31, 1982, describes a variable pitch screw propeller. The propeller has a crank arm attached to the shaft of each propeller blade and a telescoping drive arm having one end pivotally attached to the propeller hub and the other end pivotally attached to a control rod. The telescoping arm rotates the crank arm to adjust the pitch of the propeller blades to an angle substantially greater than 90 degrees as the control rod is moved longitudinally along a longitudinal axis of the hub of the propeller.
U.S. Pat. No. 4,533,296, which issued to Duchesneau et al on Aug. 6, 1985, describes a pitch control system for a variable pitch propeller. The control system has a mechanical low pitch stop which includes an electrical backup. The backup comprises an electrically operable means to effect blade pitch adjustment toward feather under conditions of failure of low pitch stop indicated by propeller operation at pitch angles in the range of beta operation, but power settings in the range of normal engine speed governor pitch control. Such operating conditions actuate a pair of switches connecting the means to a voltage source to increase blade pitch toward feather, thereby preventing overspeed operation of the propeller.
U.S. Pat. No. 4,599,043, which issued to Muller on Jul. 8, 1986, describes a controllable pitch propeller and watercraft drive. The propeller assembly has an inner housing attached to a main driveshaft, the housing having rails on the outer surface thereof. Modules carrying the propeller blades are positively mounted on the rails, each module having a housing receiving a hub cylinder and bushings axially aligned at opposite sides thereof. Each pair of bushings receives an adjusting piston having an adjusting pin which engages a groove forming a control path in a propeller hub. Each blade is adjusted by a control lever which adjusts each adjusting piston through a mechanical linkage including an adjusting sleeve and a thrust bearing and flange.
U.S. Pat. No. 4,880,402, which issued to Muller on Nov. 14, 1989, describes a method and apparatus for preventing the attachment of foreign bodies to controllable pitch propeller linkages of watercraft. The watercraft has a rotatable propeller drive shaft connec
Manthey Matthew J.
Schott Carl G.
Suhre Blake R.
Brunswick Corporation
Lanyi William D.
Look Edward K.
Nguyen Ninh
LandOfFree
Method for selecting the pitch of a controllable pitch... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for selecting the pitch of a controllable pitch..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for selecting the pitch of a controllable pitch... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2846049