Abstract: A stand-alone modular removable rudder system for watercraft having a rudder comprising a steering handle coupled to a quick release mechanism adapted to releasably secure said steering handle to said watercraft in proximity to the operator, said system further comprising, a rudder mount adapted to be coupled to the rear of the watercraft by a quick release mechanism adapted to releasably secure said rudder mount to said watercraft, said rudder being carried by a rudder support pivotal about said rudder mount and cables operatively connecting said steering handle to said rudder mount whereby the steering handle can be operated to steer the rudder.

Abstract: A controller receives a signal indicating an operating amount and an operating direction of a steering member. When the operating amount of the steering member is greater than or equal to a steering threshold, the controller causes right and left propulsion devices to generate thrusts oriented in opposite directions in a back-and-forth direction such that a vessel body is turned in a corresponding direction to the operating direction of the steering member.

Abstract: A method of controlling a marine drive on a marine vessel includes receiving a trim position instruction to adjust a trim position of the marine drive and determining an allowable steering angle range based on the trim positon instruction or adjusted trim positon of the marine drive. A trim actuator is controlled to adjust the trim position of the marine drive based on the trim position instruction and a steering actuator is controlled to automatically adjust steering positon of the marine drive to remain within the allowable steering range.

Abstract: A tiller assist hydraulic marine dampener and brake assembly has a fluid flow path with two potential flow restrictors in series. These include a solenoid valve and a hydraulic needle valve. A single cylinder piston serves to close both ends of the flow path. The tiller assist marine dampener and brake assembly in a second embodiment has a central coupling rod with recesses, a coupling link to a tiller arm, a co-axial tube, a nut adjacent each distal end of the co-axial tube securing the co-axial tube to a mounting bracket, a pair of springs co-axial with and surrounding the coupling rod and interior of the co-axial tube, a pair of adjustable end caps closing the gap between the ends of the co-axial tube and the coupling rod while also acting as stops for the springs, and a slide located between the pair of springs, and a set pin.

Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (P) connected to a main flow path (2) and a tank port (T) connected to a tank flow path (3), a working port arrangement having a left working port (L) connected to a left working flow path (9) and a right working port (R) connected to a right working flow path (10), a bridge arrangement (15) of variable orifices having a first left orifice (A2L) connected to the main flow path (2) and to a left connecting point (16) at the left working flow path (9), a first right orifice (A2R) connected to the main flow path (2) and to a right connecting point (17) at the right working flow path (10), a second left orifice (A3L) connected to the left connecting point (16) at the left working flow path (9) and to the tank flow path (3), and a second right orifice (A3R) connected to the right connecting point (17) at the right working flow path (10) and to the tank flow path (3).

Abstract: A steering actuator is for steering an outboard marine engine about a steering axis. The steering actuator has a piston device and a valve device. Hydraulic actuation of the piston device causes the outboard marine engine to pivot about the steering axis. The valve device controls a flow of hydraulic fluid to the piston device to thereby hydraulically actuate the piston device. The valve device comprises a lead screw; a motor configured to rotate the lead screw in a first rotational direction and alternately in an opposite, second rotational direction; and a ball nut coupled to the lead screw such that rotation of the lead screw causes the ball nut to axially move along the lead screw, and wherein axial movement of the ball nut along the lead screw actuates the valve device, which thereby actuates the piston device to steer the outboard marine engine.

Abstract: A hydraulic steering system for a watercraft has first and second hydraulic steering actuators for steering first and second outdrives respectively, at least one hydraulic pump selectively supplying hydraulic pressure to at least one of the first and second actuators, a steering controller operatively connected to the at least one pump, a hydraulic helm selectively supplying hydraulic pressure to the first and second actuators, an auxiliary steering input device connected to the controller, and at least one mode selection valve having first and second mode positions for steering the watercraft in first and second steering modes respectively. In the first steering mode, the hydraulic helm is hydraulically connected to the first and second actuators. In the second steering mode, the hydraulic helm is hydraulically disconnected from the first and second actuators. A watercraft having the steering system and a method for steering a watercraft are also disclosed.

Abstract: Embodiments of the present invention describe the arrangement of bearings in actuators. In particular, the bearings are fit into a surface of the actuation member instead of into the housing for the actuation member. In an exemplary embodiment of a rotary vane actuator, the bearings are fit into the axial surfaces of the vane actuation member instead of in the floor and rotor cap of the housing. In this way, the problem of an axial bearing working loose and grinding a leak path into the actuation member is addressed.

Abstract: Techniques are disclosed for systems and methods to provide accurate positioning for a hydraulic steering system without a need for a steering reference transducer. A hydraulic steering system may include a logic device in communication with an autopilot pump controller. Control and sensor signals provided by the pump controller are used to determine a linear or uncompensated steering actuator speed and an estimate of the hydraulic elasticity of the steering system, which can be modeled as an estimate of the air volume trapped within the steering system. The hydraulic elasticity/air volume estimate is used to determine a corrected or compensated steering actuator speed, and the corrected steering actuator speed is used to accurately control the steering system.

Abstract: A steering control system for a watercraft includes a device locking a steering tiller, which can be activated or deactivated for maintaining the tiller in, or moving it from, a predetermined angular position. The locking device includes a hydraulic cylinder having a rod fastened to the transom of the watercraft and a cylindrical body movable along the rod and connected to a steering arm of the motor or of the rudder member. A closed circuit, opened or closed by a valve, flows oil between the two chambers of the hydraulic cylinder and the locking device can be activated or deactivated by an actuator that opens or closes the valve. An interposition element between the steering tiller and a watercraft direction changing member is pivotably articulated to the tiller, and a member transforms the pivoting movement of the tiller relative to the interposition element into commands actuating the valve.

Abstract: An actuator unit includes a rod side chamber and a piston side chamber defined in the cylinder by a piston; a tank; a direction control valve configured to allow a working fluid discharged from the pump to be supplied selectively to the rod side chamber and the piston side chamber; a first control passage that communicates the rod side chamber with the tank; a second control passage that communicates the piston side chamber with the tank; a first variable relief valve provided on the first control passage, the first variable relief valve being configured to have a varied valve opening pressure; a second variable relief valve provided on the second control passage, the second variable relief valve configured to have a varied valve opening pressure; and a center passage that communicates the tank with the interior of the cylinder.

Abstract: A power steering system for a marine steering includes a hydraulic cylinder, an actuator block that is mounted on an outer end of a ram of the cylinder, and valving. In one embodiment, the valving is located in the hydraulic cylinder and includes at least one flow limiting valve that, through an initial portion of a stroke thereof, limits fluid flow rates through the valve to a generally constant, relatively low level. This limits the rate of extension or retraction of the ram out of or into the barrel and prevents valve chatter. In another embodiment the valving includes ball-type check valves that are located within the actuator block and that are actuated by a rocker arm assembly in the actuator block.

Abstract: The automatic steering device comprises a target rudder angle calculating unit, a target rudder angle storage unit, and a steering command unit. The target rudder angle calculating unit calculates a target rudder angle of a steering based on a heading and a target course. The target rudder angle storage unit stores a target rudder angle at a time of a previous steering command. The steering command unit outputs a steering command for instructing the steering to steer based on a newest target rudder angle calculated by the target rudder angle calculating unit and the target rudder angle at the time of the previous steering command stored by the target rudder angle storage unit.

Abstract: An actuator system having various features is disclosed. An actuator system may have a first and a second electrohydraulic servo valve. A control selector may connect one of the electrohydraulic servo valves to a cylinder and may isolate the other electrohydraulic servo valve to ameliorate leakage in response to a switching solenoid valve operating. In this manner, one electrohydraulic servo valve may be connected to a cylinder to operate the cylinder, and the other electrohydraulic servo valve may be isolated from the cylinder, for example, to provide a standby electrohydraulic servo valve.

Abstract: A floating manure agitator that floats on the surface of a manure lagoon and that may be remotely controlled to agitate manure supernatant into a slurry with sludge settling on the bottom of the lagoon. The agitator is provided with a plurality of fluid outputs, the direction of which may be controlled to motivate and steer the agitator. The outputs are angled to develop vortices of supernatant into the sludge to further mix the materials into a slurry.

Abstract: A marine vessel is disclosed having a control system for automatically controlling thrusters for steering the marine vessel for the purpose of aiding an angler who has hooked a fish. The control system will automatically control the thrusters based on the positions of the propulsion unit control levers if the control levers are split. The control system may also control the thrusters if the propulsion unit control levers have moved past a predetermined threshold. The predetermined threshold can be set by the operator of the marine vessel.

Abstract: A novel design of a hydraulic steering arrangement for a thruster of a marine vessel is specifically designed for thrusters intended to operate in an arctic environment where ice is present. To meet the arctic demands the steering arrangement is provided with a cross-over safety block arranged close to the hydraulic steering motor for absorbing the torque subjected to the thruster by ice for instance.

Abstract: A power assisted hydraulic steering system comprises a helm pump hydraulically connected to a first hydraulic actuator. A power assist pump is hydraulically connected to a second hydraulic actuator. The first and second hydraulic actuators are coupled. A flow sensing mechanism is disposed along a hydraulic conduit which hydraulically connects the helm pump to the first hydraulic actuator. The flow sensing mechanism senses when fluid flows from the helm pump to the first hydraulic actuator. A motor actuates the power assist pump when the flow sensing mechanism senses that fluid is flowing from the helm to the first hydraulic actuator. In one embodiment the first hydraulic actuator is a servo cylinder and the second hydraulic steering actuator is a drive cylinder.

Abstract: A servo-assisted steering device for vehicles includes a manual control member that is connected to a pump or the like manually driving it when the control member is rotated. The pump is connected at its delivery and suction side to one of the two chambers of one or more steering actuators through hydraulic pipes, feeding a pressurized fluid alternately to one or the other of the two chambers depending on moving direction, in particular the rotation of the control member. Assist control means for the steering actuators include a hydraulic fluid tank and automatic pumping means, which are driven and connected to the hydraulic pipes when the steering wheel is operated and which, by increasing the amount of pumped fluid, increase the pressure exerted by the pump to reduce resistance when steering the control member. The number of revolutions of the motor driving the automatic pumping means may be adjusted.

Abstract: A servo-assisted steering device for vehicles includes a manual control member connected to a shaft driving a pressurized control fluid supplying and conveying unit, which has at least two fluid conveying lines connected to one of two chambers of one or more steering actuators. A hydraulic power unit is connected to the supplying and conveying unit and includes a reservoir for the hydraulic fluid and powered pumping means, which are driven by an electric motor and which are connected to the fluid supplying/conveying circuit to supply the pressurized fluid alternately to either one or the other of the two chambers of the actuator (or actuators) depending on the rotational direction of the control member. The electric motor is energized and/or de-energized upon operation of the control member, causing the pumping means to increase the amount of pumped fluid and reduce resistance upon steering the manual control means.

Abstract: A method for controlling a marine vessel having first and second steering nozzles and first and second trim deflectors comprises generating at least a first set of actuator control signals and a second set of actuator control signals. The first set of actuator control signals is coupled to and controls the first and second steering nozzles, and the second set of actuator control signals is coupled to and controls the first and second trim deflectors. The acts of generating and coupling the first set of actuator control signals and the second set of actuator control signals result in inducing any of a net yawing force, a net rolling force, and a net trimming force to the marine vessel without inducing any other substantial forces to the marine vessel by controlling the first and second steering nozzles and the first and second trim deflectors. Also disclosed is a system for controlling a marine vessel.

Abstract: A novel retractable thruster unit for a marine vessel using a tunnel thruster includes a nozzle having an end, the end being provided with two closing plates, a top closing plate, and a bottom closing plate. The closing plates are arranged 180 degrees apart on opposite sides of the axis of the propeller and extend substantially axially from the end of the nozzle.

Abstract: A hydraulic steering system comprising a primary propulsion unit having a tiller, an auxiliary propulsion unit having a tiller, and a hydraulic steering actuator operatively coupled to the tiller of the primary propulsion unit. A tie bar couples a tie bar mount of the hydraulic steering actuator to the tiller of the auxiliary propulsion unit. A first connecting member which connects the tie bar to the tie bar mount of the hydraulic steering actuator and a second connecting member which connects the tie bar to the auxiliary propulsion unit are oriented substantially perpendicular to one another.

Abstract: A method for maintaining the heading of a ship during movements caused by waves approaching the ship from a stern direction by activating a control surface in a bow of the ship such that the control surface converts a water flow along the bow into a lateral force that opposes roll, yaw, or heeling movements and course changes.

Abstract: An independent hydraulic system for operating at least one first system used in the operation of a watercraft and adapted to be fluidly connected to one other independent hydraulic system for operating at least one second system used in the operation of the watercraft, so that actuating a driving actuator part of the independent hydraulic system, causes a flow of fluid to flow from the independent hydraulic system to the other independent hydraulic system.

Abstract: A servo-assisted steering device for vehicles includes a manual control member connected to a shaft driving a pressurized control fluid supplying and conveying unit, which has at least two fluid conveying lines connected to one of two chambers of one or more steering actuators. A hydraulic power unit is connected to the supplying and conveying unit and includes a reservoir for the hydraulic fluid and powered pumping means, which are driven by an electric motor and which are connected to the fluid supplying/conveying circuit to supply the pressurized fluid alternately to either one or the other of the two chambers of the actuator (or actuators) depending on the rotational direction of the control member. The electric motor is energized and/or de-energized upon operation of the control member, causing the pumping means to increase the amount of pumped fluid and reduce resistance upon steering the manual control means.

Abstract: A servo-assisted steering device for vehicles includes a manual control member that is connected to a pump or the like manually driving it when the control member is rotated. The pump is connected at its delivery and suction side to one of the two chambers of one or more steering actuators through hydraulic pipes, feeding a pressurized fluid alternately to one or the other of the two chambers depending on moving direction, in particular the rotation of the control member. Assist control means for the steering actuators include a hydraulic fluid tank and automatic pumping means, which are driven and connected to the hydraulic pipes when the steering wheel is operated and which, by increasing the amount of pumped fluid, increase the pressure exerted by the pump to reduce resistance when steering the control member. The number of revolutions of the motor driving the automatic pumping means may be adjusted.

Abstract: The invention relates to an auxiliary appendage(s) to improve off plane steering response and maneuverability of water jet powered crafts. The invention utilizes the pump's water flow and rotates on a horizontal axis, parallel to the water. Utilizing surface tension, drag or mechanical control the device rotates up and down on the vertical plane. The device does not cause additional sheer or stresses on water jet thrust assemblies. The invention easily attaches to water jet powered craft dramatically improving the steering capability during off-plane maneuvering. Its unique design allows adjustable torsion loading, rotates on one or both sides and allows precise tuning for multiple crafts from personal watercraft to large water jet powered crafts. This device operates on either side of the discharge nozzle to increase low speed control until the speed increases to a (craft dependent) preset point and allow the device to tilt out of the water.

Abstract: In one embodiment, a watercraft control apparatus according to the present invention includes a control member that operates a power-consuming unit or load. The control member is operably connected to the power-consuming unit or load through a drive member that transmits a control force and/or a displacement from the control member to the power-consuming unit or load. The watercraft control apparatus further includes an actuator for actuating the power-consuming unit and a magnetic unit for transducing the force and/or the displacement of the control member into a corresponding electric/electronic signal for a corresponding operation of the actuator.

Abstract: A removable retractable externally mountable dynamic positioning self contained diesel hydraulic thruster system for a floating semi-submersible vessel having a hull with a ballasted waterline, a first pontoon integral with the hull and a second pontoon integral with the hull. The hull supports a deck, wherein the system comprises: at least a pair of azimuthing thrusters, wherein at least one azimuthing thruster is removably mounted to a pontoon of a semi-submersible vessel.

Abstract: A tunnel thruster system for a vessel. The tunnel thruster system includes a thruster propulsion mechanism including a drive unit driving a transmission and propeller assembly located within a thruster tunnel. The thruster tunnel comprising a propeller section, first and second tapered tunnel sections interconnected with one another by the propeller section, the propeller section and the first and the second tapered tunnel sections oriented substantially transversely to a keel of the vessel and accommodating the transmission and propeller assembly. Each tapered tunnel section extends from the propeller section to a tunnel opening through a hull of the vessel. Diameters of the first and the second tapered tunnel sections corresponding to a diameter of the propeller section at the propeller section and taper outward toward a larger diameter at each of the corresponding tunnel openings through the hull of the vessel.

Abstract: Road and marine steering means in an amphibious vehicle are linked so that the ratio between them is variable. In a first embodiment, an arm connects a lever to a steering rack. A cable operates the marine steering means. The lever pivots about a pin, which may be moved along a slot by the motor and gearbox driving screw shaft. At pin position A, full road steering travel x is achieved with minimal marine steering travel. At pin position B, road and marine steering have equal travel x?; and at position C, full marine steering travel z is achieved with minimal road steering travel y. In a further embodiment, a lever arm fixed to steering rack casing has a cam profile constraining pin. Full marine steering travel z of the cable is achieved over rack travel y. The steering wheel controls both road and marine steering.

Abstract: This invention is a method of capturing renewable energy, using power from ocean waves approaching the continental shores of the world as they build to greater height and power on impact with the shallower waters, and the purpose of this invention is to extract from these waves the maximum amount of energy possible by utilizing pitching vessels in the form of barges anchored perpendicular to the incoming swells and in turn causing large heavy masses in the form of liquids or massive steel balls to shift backwards and forward as the waves pass under the vessel creating a free surface effect to either generate power, convert salt water to fresh, or a combination of both—with a goal of generating 1 megawatt of power per barge providing an average wave height of 5 ft.

Abstract: A hydraulic lock of a tiller-based watercraft steering system is responsive to tiller release to lock a watercraft's steered element in the last commanded position upon tiller release. The hydraulic lock can be controlled through an actuator assembly that is provided between a tiller arm and the watercraft's steered element. One or more cables connect the actuator assembly to other components of the hydraulic lock. A thermal compensator regulates pressure within the hydraulic lock by accommodating changes in temperature related characteristics of the fluid within the hydraulic lock Increases in fluid pressure due to thermal expansion can be mitigated within the thermal compensator by automatically or manually directing a volume of fluid from the hydraulic lock, through a compensating valve assembly, and into a reservoir. Decreases in fluid pressure can be mitigated by directing fluid from the reservoir back into the hydraulic lock.

Abstract: A ship for use at high speed and/or heavy seas having a single long and slender hull, a sharp bow and the aft end of the hull has a flat or slightly V-shaped bottom with at least one aft rudder, and at least one propeller or water jet for propulsion whereby the foreship has a draught that is equal or more than the draught of the aft end. The bow has a control surface that converts the water flow along the forward moving ship into an adjustable lateral force.

Abstract: An apparatus and method for providing power assisted steering for a marine craft having a manually operable steering pump and a hydraulic steering actuator. A powered hydraulic pump is hydraulically connected between the manually operable pump and the actuator. Hydraulic fluid volume output of the steering pump and hydraulic fluid volume output of the powered pump are sensed. The fluid output of the steering pump is compared with the fluid output of the powered pump and the powered pump is operated so that the output of the powered pump is commensurate with output of the steering pump.

Abstract: A rudder control system having adjustable rudder drive turn off and “turn on,” and component wear monitoring. The rudder drive “turn off” being adjusted in accordance with the rudder stop position relative to the rudder order stop position, thereby improving position accuracy. Frequency of system “turn on” is compared to an acceptable “turn on” frequency for solenoid operation. Should the “turn on” frequency exceed the acceptable “turn on” frequency, the rudder angle at which “turn on” is implemented is adjusted to protect solenoids in the system from burnout. The rate of change of the rudder repeatback signal is monitored. A slow rate of change providing an indication of some component problem.

Abstract: A hydraulic system for a sterndrive marine propulsion device directs the flow of hydraulic fluid through the body and peripheral components of a gimbal ring in order to reduce the number and length of flexible hydraulic conduits necessary to conduct pressurized hydraulic fluid from a pump to one or more hydraulic cylinders used to control the trim or tilt of a marine drive unit relative to a gimbal housing.

Abstract: A tiller-based watercraft steering system is responsive to tiller release to lock a watercraft's steered element in the last commanded position upon tiller release. The system is locked by closing a valve assembly to prevent flow to opposed chamber of a hydraulic lock coupled to the steered element. The tiller preferably comprises an actuator portion which is movable relative to the remainder of the tiller. The actuator portion may, for example, be a grip on an articulating outer end portion of a tiller arm. The valve assembly may be connected to the hydraulic lock to form a combined module. It may be actuated by a mechanical link such as one or more cables leading from the actuator portion of the tiller to the valve assembly. The system may be used as either a manual or a power-assisted steering system.

Abstract: In a steering device for a small watercraft that has at least two outboard motors which propulsive directions and propulsive forces are individually controllable. The steering device can have a steering wheel that can be inclined relative to an axis of a steering shaft in any directions including a fore to aft direction and a transverse direction. A control unit that controls shift units and throttle units of the outboard motors so that a hull moves toward a side that is directed by the inclination of the steering wheel.

Abstract: An apparatus and method for providing power assisted steering for a marine craft having a manually operable steering pump and a hydraulic steering actuator. A powered hydraulic pump is hydraulically connected between the manually operable pump and the actuator. Hydraulic fluid volume output of the steering pump and hydraulic fluid volume output of the powered pump are sensed. The fluid output of the steering pump is compared with the fluid output of the powered pump and the powered pump is operated so that the output of the powered pump is commensurate with output of the steering pump.

Abstract: The invention concerns a hydraulic steering arrangement with a steering motor, a supply path between a pressure source and the steering motor, in which supply path a throttling device and a measuring motor are located, a return path between the steering motor and a pressure sink, in which return path a return throttle is located, and a bypass path, which connects the supply path and the return path on the pressure source end or the pressure sink end, respectively, and which has a bypass throttle. It is endeavoured to make such steering arrangements suitable for fast motorboats. For this purpose it is ensured that with a load on the steering motor the pressure drop over the bypass throttle is larger than the sum of the pressure drops between a point before the first throttle and a point after the last throttle of the throttling device.

Abstract: There is provided a hydraulic steering assembly for applying a force to a tiller of a marine, outboard propulsion unit. The steering assembly comprises a hydraulic steering actuator including a cylinder and an elongated piston rods. A pivot member is pivotally mounted on the tiller of the propulsion unit for pivoting about a first link axis which is parallel to the steering axis. There is a pair of actuator arms, each actuator arm being connected to the cylinder and having a portion extending radially outwards with respect to the piston rod axis. Each actuator arm includes an integral cylindrical projection. The pivot member has a complementary cylindrical recess for each integral cylindrical projection and the pivot member thereby rotatably receives each cylindrical projection. Preferably, each cylindrical projection and actuator arm comprise one piece. At least one of the actuator arms is removable.

Abstract: A hydraulic steering apparatus 1 has a substantially bow-shaped frame 2, which includes a pair of end portions 2a bent forward. A piston rod 3 is supported by and between the end portions 2a. A hydraulic cylinder 5 is supported by the piston rod 3 slidably along it. The frame 2 also includes a middle portion 2A, which has bolt holes 2B cut through it. Bolts 11 extend through the bolt holes 2B and engage with the front end of the swivel bracket 41 of an outboard engine 40 to fix the frame 2 to the bracket. The cylinder 5 is linked to the front end of the steering lever 46 of the engine 40 by a steering link 7.

Abstract: A hydraulic system for a marine vessel incorporates a single hydraulic pump that can be driven by either first or second motive devices, such as an internal combustion engine or an electric motor. Depending on the circumstances, the pressure required by the hydraulic system is provided by the pump when it is driven by either the first or second motive devices. As a result, only two motive devices can provide the necessary driving capacity for the hydraulic pump under all operating circumstances, including those when the engine is not running.

Abstract: A helm pump (10) rotated either in forward or reverse direction by operating a steering wheel (13) and discharges a liquid of a quantity proportional to the rotating angle, and a double action cylinder moves a rudder (27) and is provided on rudder (27) side of the ship, helm pump (10) and the double action cylinder being connected with the hydraulic circuit of fully closed construction, to move the rudder (27) by an amount corresponding to the amount of liquid discharged from the helm pump (10). A second pump generates discharging pressure in the same direction as the discharging direction from helm pump (10) against resistive pressure generated by the rotation of helm pump (10) due to the operation of steering wheel (13) is installed in series in part of the fully closed hydraulic circuit, so the steering resistance of steering wheel (13) is automatically reduced by the action of the second pump.

Abstract: An outboard motor is provided with an internally contained cylinder and moveable piston. The piston is caused to move by changes in differential pressure between first and second cavities within the cylinder. By adding a hydraulic pump and a steering valve, the hydraulic steering system described in U.S. Pat. No. 6,402,577 is converted to a power hydraulic steering system by adding a hydraulic pump and a steering valve to a manual hydraulic steering system.

Abstract: A steering system for amphibious vehicle includes a control connected to road steering means. Ram is conventionally used to assist road steering, but by disconnecting command valves, it becomes a hydraulic master cylinder, driving slave cylinder; and thus marine steering means. Valves and hydraulic reservoir enable the marine steering to be disconnected from road steering. The marine steering means may be center biased by springs. A sensor and control means may synchronize center positions of road and marine steering. The valve and port layout may also achieve this goal. Alternatively, power steering in road mode may be maintained by fitting a master cylinder in parallel or in series with steering means; and may have hydraulic, electro-hydraulic, electric, or magnetic assistance.

Abstract: An improved and simplified marine power steering device that provides assist by selectively operating an electric motor driven hydraulic motor to provide the assist. This eliminates pumps that are constantly driven by the watercraft engine. Also the entire assist unit is formed as a single assembly to minimize the hydraulic conduits and their assembly.

Abstract: The present application is a method and apparatus for moving and steering a vessel traveling in water. The arrangement for moving and steering a vessel includes a propulsion unit having a chamber positioned outside the vessel equipment for rotating a propeller arranged in connection with the chamber, and a shaft means connected to the chamber for supporting the chamber in a rotatable manner at the hull of the vessel. At least one hydraulic motor if used for turning the shaft means in relation to the hull of the vessel for steering the vessel. The arrangement also includes a means for altering the rotational displacement of the hydraulic engine.