US 2003/0150367 A1Published application

Power assist marine steering system

AssigneeMark X Steering Systems, LLC

InventorJames M. Hundertmark

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Abstract

A power steering assist system for a watercraft includes a hydraulically actuated steering cylinder assembly and a helm. The helm has a high pressure port being coupled to a fluid pressure source, a return port coupled to a reservoir, and a metering port coupled to a second chamber of the steering cylinder. A control valve assembly in the helm is switchable between at least first and second states to alternatively couple a metering element in the helm to the high pressure and return ports of the helm, respectively, hence alternatively permitting pressurized fluid to flow into the metering port from the metering element to steer the watercraft in a first direction and from the metering port into the metering element to steer the watercraft in a second direction. The system is simple, compact, reliable, and still usable in watercraft having multiple engines and/or multiple helms.

Claims22

Dependent claims

A power steering assist system for a watercraft, comprising:

(A) a hydraulically actuated steering cylinder assembly that is configured for connection to a steered mechanism of the watercraft, said steering cylinder assembly including
(1) a steering cylinder,
(2) a steering piston that is mounted in said steering cylinder to define first and second chambers on opposite sides thereof, and
(3) a rod that is affixed to said steering piston, wherein one of said rod and said steering cylinder is movable relative to the other and is configured for connection to the steered mechanism;
(B) a fluid pressure source that has an outlet fluidically coupled to said first chamber in said steering cylinder;
and
(C) an operator-controlled helm that is spaced from said steering cylinder assembly and that has high pressure, return, and metering ports formed therein, said high pressure port being coupled to said fluid pressure source, said return port being coupled to a reservoir, and said metering port being coupled to said second chamber of said steering cylinder, wherein said helm includes
(1) a metering element having at least first and second ports, said second port being coupled to said metering port in said helm;
and
(3) a control valve assembly that is coupled to said metering element and that is switchable between at least first and second states to alternatively couple said first port in said metering element to said high pressure and return ports of said helm, respectively, thereby alternatively permitting pressurized fluid to flow into said metering port from said metering element and from said metering port into said metering element.

7 more elements

A power steering assist system for a boat, comprising:

(A) a hydraulically actuated, unbalanced steering cylinder assembly that is configured for connection to a steered mechanism of the boat, said steering cylinder assembly including
(1) a stationary steering cylinder that has a rod end and a cylinder end,
(2) a steering piston that is slidably mounted in said steering cylinder to define first and second chambers on opposite sides thereof, wherein fluid pressures in said first and second chambers act on first and second different effective areas of said steering piston, and
(3) a rod that is affixed to said steering piston, that extends axially through said rod end of said steering cylinder but not through said cylinder end, and that is configured for connection to the steered mechanism;
(B) a pump that has an inlet and an outlet fluidically coupled to said first chamber in said steering cylinder;
(C) a reservoir that is connected to said pump inlet;
and
(D) a helm that is spaced from said steering cylinder assembly and that includes
(1) a steering shaft;
(2) a helm casing configured for mounting through a dash of the boat and having high pressure, return, and metering ports formed therein, said high pressure port being coupled to said pump, said return port being coupled to said reservoir, said metering port being coupled to said second chamber of said steering cylinder,
(3) a metering element which is rotatably mounted in said helm casing and which has at least first and second ports, said second port being coupled to said metering port in said helm, and
(4) a control valve assembly including
a) a valve body that is rotatably mounted in said helm casing, that is coupled to said metering element so as to rotate therewith, and that is rotatably coupled to said steering shaft, wherein said valve body has a first passage formed therein that couples said high pressure port to said first port in said metering element and a second passage formed therein that couples said return port to said first port in said metering element, and
b) first and second two-way/two-position valves located in said first and second passages,
wherein said control valve assembly is coupled to said steering shaft such that both said first and second valves remain closed when the steering shaft is in a stationary position, 2) movement of said steering shaft in a first direction from the stationary position opens said first valve while leaving said second valve closed, and 3) movement of said steering shaft in a second direction from the stationary position opens said second valve while leaving said first valve closed.

12 more elements

A method of steering a watercraft, comprising:

(A) placing a pressure source in fluid communication with a high pressure port of a helm casing of a helm and a first chamber in a hydraulic steering cylinder located remote from said helm casing, said first chamber being separated from a second chamber by a steering piston, a driven member being formed by one of said steering cylinder and said rod and being coupled to a steered mechanism of the watercraft;
(B) in response to movement of a steering mechanism of the watercraft in a first direction from an at-rest position thereof, causing a metering element in said helm casing to rotate in a first direction and deliver fluid to said second chamber in said steering cylinder, thereby causing said driven member to move in a first direction;
and
(C) in response to movement of the steering mechanism in a second direction from the neutral position, causing said metering element to rotate in a second direction to permit hydraulic fluid to flow into metering element from said second chamber in said steering cylinder, thereby causing said driven member to move in a second direction opposite said first direction.

1 more element

A method of steering a watercraft, comprising:

(A) placing a pressure source in fluid communication with a high pressure port of a helm casing of a helm and a first chamber in an unbalanced hydraulic steering cylinder located remote from said helm casing, said first chamber being separated from a second chamber by a steering piston, fluid pressures in said first and second chambers acting on first and second different effective areas of said steering piston, and a driven member being formed by one of said steering cylinder and said rod and being coupled to a steered mechanism of the waterraft;
(B) rotating a steering shaft in a first direction to drive a valve actuator in said helm casing to move from a position in which supply and return valves mounted in a valve body in said helm casing are closed to a position in which said supply valve is open and said return valve is closed, thereby causing a metering element in said helm casing to rotate in a first direction and deliver fluid to said second chamber in said steering cylinder, hence causing said driven member to move in a first direction;
(C) terminating rotation of said steering shaft, whereupon continued rotation of said metering element drives said valve body to rotate to a position closing said supply valve, thereby cutting off fluid flow through said metering element and terminating driven member movement;
(D) rotating said steering shaft in a second direction to drive said valve actuator to move from a position in which said supply and return valves are closed to a position in which said return valve is open and said supply valve is closed, thereby causing fluid to flow through said metering element from said second chamber in said steering cylinder, hence causing said driven member to move in a second direction;
and
(E) terminating rotation of said steering shaft, whereupon continued rotation of said metering element drives said valve body to rotate to a position closing said return valve, thereby cutting off fluid flow through said metering element and terminating driven member movement.

3 more elements

Dependencies are inferred from the claim text.