Steering system for watercraft

ABSTRACT

A watercraft includes moveable sponsons that are moved in response to movements of the handlebars and the accelerator lever. The watercraft can include a number of different kinds of actuators for moving these sponsons relative to the hull of the watercraft. In preferred embodiments, the sponsons are moved outwardly and/or downwardly relative to the hull.

INFORMATION

DETAILED DESCRIPTION OF THE INVENTION

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the present invention will now be described with reference to the drawings of preferred embodiments, which are intended to illustrate and not to limit the invention. The drawings comprise the following figures:

FIG. 1 is a side elevational view of a personal watercraft with certain internal components, including a fuel tank, an engine, and part of a drive train, shown in phantom;

FIG. 2 is schematic side elevational view of the watercraft shown in FIG. 1 illustrating portions of a control system included therein;

FIG. 3 is a front elevational view of the watercraft shown in FIG. and including sponsons on port and starboard sides thereof;

FIG. 4 is an enlarged port side elevational view of the watercraft shown in FIG. 1, and illustrating a retracted position of the port side sponson;

FIG. 5 is an enlarged port side view of the watercraft illustrated in FIG. 4, with the sponson in a deployed position;

FIG. 6 is an enlarged rear elevational view of the watercraft illustrated in FIG. 4 with the sponson in an retracted position;

FIG. 7 is a rear elevational view of the watercraft illustrated in FIG. 6 with the sponson in the deployed position;

FIG. 8 is a schematic illustration of a sponson module included in the watercraft illustrated in FIG. and including the sponson illustrated in FIGS. 4-5;

FIG. 9 is a schematic illustration of a modification of the sponson module illustrated in FIG. 8;

FIG. 10 is an enlarged port-side elevational view of a modification of the watercraft illustrated in FIG. 4, illustrating a sponson of the sponson module illustrated in FIG. 9 in a retracted position;

FIG. 11 is an enlarged side elevational view of the watercraft illustrated in FIG. 10 with the sponson illustrated in a deployed position;

FIG. 12 is a schematic illustration of a modification of the sponson module illustrated in FIG. 9;

FIG. 13 is a schematic illustration of a modification of the sponson modules illustrated in FIG. 8-12;

FIG. 14 is an enlarged rear elevational view of a modification of the watercraft illustrated in FIG. and including the sponson module illustrated in FIG. 13, showing the sponson in a retracted position.

FIG. 15 is an enlarged rear elevational view of the watercraft illustrated in FIG. 14, with the sponson in a deployed position.

FIG. 16 is a schematic illustration of another modification of the sponson modules illustrated in FIGS. 8-16;

FIG. 17 is a flow chart illustrating a control routine that can be used with any of the sponson modules illustrated in FIGS. 8-16.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With primary reference to FIG. and additionally to FIGS. 2 and 3, an overall configuration of a watercraft is described below. The watercraft includes a sponson control module configured in accordance with a preferred embodiment of the present invention. The sponson control module has particular utility with small watercraft, and is thus described in the context of a personal watercraft. The control module, however, can be applied to other types of watercraft as well, such as, for example, small jet boats and the like.

The watercraft includes a hull which comprises a lower hull section and an upper deck section . The lower hull section may include one or more inner liner sections to strengthen the hull or to provide mounting platforms for various internal components of the watercraft . Both the hull sections , are made of, for example, a molded fiberglass reinforced resin or a sheet molding compound. The lower hull section and the upper hull section are coupled together to define an internal cavity . The sections , are connected together along a bond flange . An engine compartment may be an area within the internal cavity or may be divided from one or more other areas of the internal cavity by one or more bulkheads (not shown).

A bow portion of the watercraft slopes upwardly from the front of the watercraft toward the rear. Rearward from the bow portion , a control mast is supported by the upper deck. The control mast supports a handlebar for pivotal movement about a steering axis.

The handlebar is provided primarily for a rider to control the direction in which the watercraft travels. The handlebar also carries other control devices such as, for example, but without limitation, a throttle level lever (not shown). The throttle lever is one type of a throttle operator that can be used with the present watercraft . Additionally, the throttle lever can be directly connected to the throttle valves of the engine (described below), or can be configured to generate and transmit a digital or analog signal which is used by the engine as a load or torque request from the operator. In such an embodiment, the load or torque request is used to control an electric motor for moving the throttle valves or another device for controlling the power output of the engine.

A seat extends longitudinally along a center line of the hull at a location behind the control mast . Thus, the area behind the control mast defines a rider's area. The seat has a generally saddle type shape so that a rider can straddle the seat during operation. The seat is generally formed of seat pedestal defined by the upper hull section and a cushion . The cushion , which preferably includes a rigid backing, is supported by the seat pedestal . The seat cushion preferably is detachably connected to the pedestal .

An access opening (not shown) is defined in an upper surface of the pedestal . Preferably, the cushion closes the access opening when it is connected to the pedestal . The access opening preferably is sized to allow an operator to access the engine compartment .

A fuel tank is supported within the internal cavity . The fuel tank is coupled with a fuel inlet port positioned on a top surface of the upper hull section via a filler duct. A closure cap (not shown) closes the fuel inlet port.

At least a pair of air ducts or ventilation ducts are provided on both sides of the upper hull section so that ambient air can be enter the internal cavity through the ducts. Except for the air ducts, the internal cavity is substantially sealed so as to prevent water invasion into internal cavity .

A jet propulsion system is configured to propel the watercraft . The jet propulsion system includes a tunnel formed on an underside of the lower hull section . In some hull designs, the tunnel is isolated from the engine compartment by a bulk head.

The tunnel includes a downwardly facing inlet port opening toward a body water in which the watercraft is operating. For example, the line WR illustrated in FIG. 1 shows the approximate water level of the watercraft when the watercraft is at rest in a body of water. The line Wp represents the water line when the watercraft is planing along the surface of the body of water in which the watercraft is operating.

The port is positioned so that water can be drawn into the jet propulsion system when the watercraft is floating at the waterline WR or planing at the line WP. A jet pump unit is disposed within the tunnel so as to communicate with the port . The jet pump unit includes a jet pump housing . An impeller is disposed within the housing so as to be rotatable about an impeller axis. A ride plate closes a bottom of the tunnel .

An impeller shaft extends forwardly from the impeller into the internal cavity . The impeller shaft can be a single shaft both rotatably supporting the impeller within the housing and driving the impeller , or can be formed from a plurality of shafts.

At the rear end of the housing , a discharge nozzle is disposed. Additionally, a deflector or “steering” nozzle is pivotally mounted to a discharge end of the nozzle . In particular, the deflector nozzle is mounted for pivotal movement about a generally vertically extending axis. A steering mechanism connects the steering deflector with the handlebar . The mechanism can be Bowden-wire type actuator, which is well known in the art. Together, the handlebar , steering device and the deflector nozzle define the steering system for the watercraft , the handlebar defining a steering input device.

The watercraft also includes an engine disposed within the internal cavity . The engine can be disposed within in a separate part of the internal cavity with defining an engine compartment, which may be separated from the remainder of the internal cavity by one or more bulkheads (not shown).

Preferably, the engine operates at a four stroke combustion principle. Thus, the engine preferably includes a cylinder block defining at least one cylinder bore, a piston reciprocally mounted within the cylinder bore, and a cylinder head closing an upper end of the cylinder bore. Together, the cylinder head, cylinder bore, and piston define a combustion chamber therein.

A lower end of the engine preferably includes a crank case. A crank shaft is disposed within the crank case. Together, the cylinder head, cylinder block, and crank case define the engine body of the engine .

The crank shaft of the engine can extend rearwardly from the engine body to a coupling device . The coupling device can connect the crank shaft to the impeller shaft . Preferably, a transmission is disposed within the crank shaft or connected to a rear portion of the engine which drives an output shaft . Preferably, the transmission includes a gear reduction to drive the output shaft at a speed lower than the crank shaft of the engine . Thus, the engine can run at speeds that are more efficient for a four cycle engine while allowing the impeller shaft to rotate at speeds that are more efficient for a jet pump.

The engine preferably includes an air induction system (not shown) configured to guide air to the combustion chamber of the engine . Preferably, the induction system includes an air silencing device for reducing the noise associated with the movement of induction air. Additionally, the induction system preferably is configured to reduce the likelihood of water being ingested into the induction system during operation of the engine .

A throttle body (not shown) is disposed within the induction system to regulate or meter an amount of air flowing there through. The throttle valve can comprise a throttle body having a butterfly-type valve mounted therein. Of course, other types of metering systems can be used in place of a throttle device having a butterfly-type throttle valve.

As noted above, a throttle actuator cable can connect the throttle level on the handlebar to the throttle valve of the engine . Alternatively, a throttle lever position sensor can be mounted for communication with a throttle level to generate and transmit a signal indicative of the position of a throttle lever. As such, the signal is also indicative of an engine load or torque request from an operator of the watercraft . Using this design, the throttle valve can be operated by an electric actuator configured to control the opening of the throttle valve in accordance with the load or torque request indicated by the operator.

The engine also includes a fuel supply system. The fuel supply system includes the fuel tank (FIG. ), a charge forming device, and a fuel delivery mechanism that connects the fuel tank with the charge forming device. The charge forming device can be any one of a number of fuel charge forming devices known in the art. For example, but without limitation, the charge forming device can be a carburetor, a fuel injector configured to inject fuel into the induction system, or fuel injector configured to inject fuel directly into the combustion chamber. Preferably, the charge former is a fuel injector.

Each fuel injector includes a solenoid operating a fuel valve. When the solenoid is activated, the fuel valve is opened, thereby allowing pressurized fuel to be sprayed through the fuel injector. The sprayed fuel is mixed with air for combustion in the combustion chamber.

Preferably, the watercraft also includes a feedback control system for controlling various aspects of the operation of the engine . For example, the feedback control system can include an electronic control unit (ECU) which receives signals from various sensors and outputs control signals to various actuators, described in greater detail below. Preferably, where the fuel system of the watercraft comprises a fuel injection system, the ECU controls the timing and duration of fuel injection from the fuel injectors. The ECU can also be configured to control other parts of the fuel system, for example, but without limitation, a fuel pump for maintaining a predetermined pressure in the fuel system.

The engine also includes an ignition or firing system. Spark plugs (not shown) of the ignition system are fixed to the cylinder head of the engine . A spark gap of each spark plug is exposed within an associated combustion chamber. Each spark plug ignites an air fuel charge at an ignition timing controlled by the ECU as part of the feed-back control system.

The ignition system preferably includes an ignition mechanism having an ignition coil and an igniter. The ignition coil preferably is a combination of a primary coil element and a secondary coil element that are wound around a common core. The secondary coil element is connected to the spark plugs while the primary coil element is connected to the igniter. The primary coil element also is coupled with a power source (e.g., a battery). The igniter abruptly cuts-off the current flow in response to an ignition timing control signal from the ECU . A high voltage current flow consequently occurs in the secondary coil element. The high voltage current flow forms a spark at each spark plug. The ECU controls the ignition timing of the spark plugs in accordance with any known strategy as part of the feedback control system.

The engine further includes an exhaust system configured to discharge burnt air fuel charges, i.e., exhaust gases, from the combustion chambers therein. Exhaust ports are defined in the cylinder head (where the engine is a four cycle engine) and communicate with associated combustion chambers. An exhaust manifold connects the individual ports to a common exhaust pipe. The exhaust pipe can merge the individual exhaust gas passages defined by the port into a single passage, or can extend the individual exhaust paths to a point further down stream in the exhaust system. For example, multiple exhaust pipes can extend around a part of the engine . At any point along the exhaust pipes, the exhaust passages can be merged together into a single exhaust gas passage. Additionally, another exhaust pipe extends around the other side of the engine to an exhaust discharge opening to the atmosphere. Optionally, the exhaust system can include a further exhaust silencer also known as a “water trap,” configured for further reducing the likelihood that water can flow upstream to the exhaust system toward the engine. Preferably, the exhaust discharge is disposed in the tunnel below the water line WR.

As noted above, the ECU controls engine operations including fuel injection from the fuel injectors and firing of the spark plugs, according to various control maps stored in the ECU . In order to determine appropriate control scenarios, the ECU utilizes maps and/or indicies stored within the ECU with reference to data collected from various sensors. For example, the ECU may refer to data collected from a throttle valve position sensor , connected to the ECU via a throttle position data line , which is mounted in the vicinity of the throttle valve of the engine so as to detect an angular position, which is indicative of an opening degree, of the throttle valve. Additionally, other sensors can be provided for sensing engine running conditions, environmental conditions, or other conditions of the engine that will affect engine performance.

For example, the watercraft can include one or more plurality of crank shaft position sensors. Such crank shaft position sensors can be configured to provide signals to the ECU indicative of engine speed and/or crank shaft position. The watercraft can also include a combustion condition sensor or oxygen (O2) sensor configured to detect the in-cylinder combustion conditions by sensing a residual amount of oxygen in the combustion products at a point in time approximately when the exhaust port is opened. The output from the oxygen sensor can be transmitted to the ECU .

The watercraft can also include a watercraft speed sensor . In the illustrated embodiment, the watercraft speed sensor is a pitot-tube type sensor having an opening positioned in the inlet of the tunnel . As such, the watercraft speed sensor can generate a signal indicative of the pressure at the opening and transmit the signal to the ECU through an engine speed data line . The ECU can be configured to convert the pressure signal to a watercraft speed. Alternatively, the watercraft speed sensor can be of any known type of watercraft speed sensor, for example, but without limitation, a paddle wheel. Additionally, the sensor or another sensor used for detecting watercraft speed, can be mounted at other locations on the watercraft . For example, but without limitation, on the ride plate .

The watercraft can also include a steering sensor . In the illustrated embodiment, the steering sensor is mounted adjacent to the handlebar . In particular, the steering sensor is mounted adjacent to a mounting assembly of the handlebar . The steering sensor can be configured to detect if the angle at which the handlebars are turned, is greater than a predetermined magnitude. Preferably, the steering sensor can detect the magnitude of the angle at which the handlebars are turned from a center position. Additionally, the sensor preferably is configured to detect whether the handlebars are turned toward the port or starboard sides.

The sensor is also configured to transmit a signal to the ECU . For example, the sensor can transmit a steering signal to the ECU via a steering data line .

The above-noted sensor correspond to merely some of those conditions which may be sensed for purposes of engine control. It is, of course, practicable to provide other sensors such an intake air pressure sensor, intake air temperature sensor, a trim angle sensor, a knock sensor, a watercraft pitch sensor, and an atmospheric temperature sensor in accordance with various control strategies.

With reference to FIG. 3, the watercraft also includes a port side sponson and a starboard side sponson . As shown in FIG. 3, the sponsons , , are disposed so as to contact the surface of the water when the watercraft is floating on a surface of a body of water at the waterline WR. The sponsons , are connected to lateral side surfaces , , respectfully, of the lower hull section . The illustrated position is a preferred position, but it is not necessary for the sponsons , to be mounted in the illustrated position.

As noted above, the watercraft includes a sponson module for moving at least one of the sponsons , relative to the hull , between a retracted position and a deployed position. FIGS. 3, and illustrate the retracted position of the sponson . FIGS. 5 and 7 illustrate a deployed position of the sponson .

With reference to FIG. 6, the sponson includes an inner surface which faces toward the lateral side surface of the lower hull . A second surface of the sponson extends outwardly from the lower edge of the surface . The third surface extends generally downwardly from the second surface , toward a body of water in which the watercraft can operate. The sponson also includes an outer surface extending from the lower edge of the surface and faces in a direction away from the outer side surface of the lower hull portion .

As shown in FIG. 6, in the retracted position, the sponson is mounted such that the intersection of the inner surface and the second outwardly extending surface is at about an outer chine of the lower hull section . As such, the sponson provides additional traction for the watercraft when the watercraft is in a turn.

Sponsons such as the sponson are particularly useful for small planing-type watercraft during turns at planing speeds. Because of the relatively low profile of the sponson body , the sponson provides a limited amount of traction along the surface of the water in which the watercraft is operating. Thus, the traction provided by the sponson is proportional with watercraft speed and the turning angle, yet is limited as compared to watercraft which have rudders, and thus provides a substantially different effect than that generated by rudders.

With reference to FIGS. 4 and 5, the sponson is positioned approximately at the stern of the watercraft and has a length substantially shorter than the length of the hull . In the illustrated embodiment, the sponson has a length roughly equal to about ⅙th of the watercraft . For heavier watercraft or for watercraft designed to accommodated multiple passengers, however, longer sponsons can be used.

With reference to FIGS. 3 and 6, the shape of the sponson tapers from its aft end to a generally blunt nose positioned at its fore end to give the body of the sponson a substantially streamline shape in a direction of water flow over the sponson . Thus, the lateral width of the sponson increases from its blunt nose to its aft end.

The outer surface of the sponson also tapers in size in the vertical direction (i.e., in a direction generally normal to the water surface WR) such that the outer portion smoothly transitions into the blunt nose of the sponson body in the fore direction. The size and shape of the sponson body is desirably selected according to the preference of a rider and the number of riders. It is contemplated that other shapes and sizes of sponson bodies can be used.

With reference to FIGS. 5 and 7, a guide mechanism secures the sponson to the lower hull and is configured to allow the sponson to move from the retracted position illustrated in FIG. 6 to the deployed position illustrated in FIG. .

It has been found that by moving the sponson from its retracted position to a deployed position, for example, but without limitation, in a direction generally downward, or generally outward from the side surface of the hull , the resulting increase in hydrodynamic resistance can be sufficient to cause the watercraft to turn when the watercraft is moving under its own momentum, with the engine at a lower speed than that which is sufficient to cause the watercraft to turn quickly under the force of the water jet deflected by the deflector nozzle . For example, when the watercraft is operated at low speed in a water displacement mode, i.e., when the watercraft is moving through the water at the waterline WR, fine adjustments to the attitude of the watercraft can be difficult, such as when the watercraft is being driven toward a dock for docking maneuver, or onto a trailer to remove the watercraft from the water. It has been found by moving the sponson relative to the hull , the increased hydrodynamic resistance used to convert the forward momentum of the watercraft into yaw to thereby change the attitude or direction in which the watercraft travels.

The guide mechanism is configured to allow the sponson to move along a fixed path with one degree of motion between the retracted position (FIG. 6) and the deployed position (FIG. ). This provides a further advantage in that the sponson can be held more rigidly in the deployed position. Thus, further movement from the sponson , e.g., in a direction prependicular to the movement allowed by the guide , is prevented which could otherwise cause fluctuations in the effects provided by the sponson in the deployed position.

With reference to FIG. 8, a modification of the guide mechanism is illustrated therein and identified generally by the reference numeral A. In the illustrated embodiment, the guide mechanism A includes three circular disks , which are contained within the sponson so as to be rotatable relative to the sponson . Thus, the sponson , in this embodiment, includes a plurality of circular holes . Plugs (not shown) preferably are disposed on either side of the disks to enclose each of the disks in place within the holes . Each of the circular disks , as well as the plugs at least on the inner side of the sponson , include a through hole.

A rotational shaft is connected to each of the disks . The shaft desirably includes external splines which cooperate with internal splines formed within the hole of the circular disks . The shafts extend from the inner side of the disks through a hole in the inner plug element of the sponson body . A fastener (not shown) engages the outer end of each shaft through the hole of the outer sponson body plug to secure the sponson body onto the shafts .

Each shaft is supported by a bushing (not shown) positioned within a hole that extends through the sidewall of the lower hull . Each bushing includes a flange which mates against an inner surface of the sidewall and includes an angular collar (not shown) which extends through the wall and fits within a counter bore formed within the inner plug elements of the sponson body .

The bushing also includes a central hole through which the corresponding shaft extends. A seal (not shown) is placed between the bushing and the shaft to prevent ingress of water into the hull through the hull in the sidewall . In this matter, each bushing supports the corresponding rotational shaft permits rotational movement of the shaft relative to the bushing and the seal. The shaft , in turn, couples the sponson to the sidewall .

The shaft and disks also define a travel path of the sponson relative to the sidewall . Each shaft is eccentrically positioned on the respective disk . Thus, rotational movement of the shaft about a fixed rotational axis causes the attached sponson body to move vertically relative to the rotational axis. In the illustrated embodiment, the shafts desirably rotate 180 degrees from a fully raised position (the retracted position illustrated in FIG. 6) to a fully deployed position (illustrated in phantom).

An actuator is configured to move the sponson between the retracted and deployed positions. In the illustrated embodiment, the actuator comprises a gear train driven by a motor . The gear train includes a worm gear which drives a plurality of pinions .

Each rotational shaft supports one the pinions on its inner side, i.e., a side of the shaft that extends into the hull . In the illustrated embodiment, the inner end of each shaft includes an external spline which cooperates with an internal spline of the pinion . A suitable fastener holds the pinion onto the shaft .

The worm gear cooperates with the pinions . The worm gear includes a corresponding thread arrangement which cooperates with the teeth of the pinions in a known manner. The worm gear desirably is held in a meshing engagement with the pinions and is suitably journaled for rotation relative to the pinions . In this manner, rotation of the worm gear , drives the pinions to rotate the rotatable shafts in unison.

The motor can be an electric reversible stepper motor or similar type of reversible actuator motor which drives the worm gear , through a shaft , in a rotational directions so as to raise and lower the sponson . By rotating the worm gear in the first direction, the worm gear rotates the pinions and corresponding rotational shafts in corresponding direction (e.g., clockwise direction) to raise the sponson . That is, the rotational movement of the eccentrically positioned shafts rotates the circular disks upwardly. As a result, the sponson moves upwardly to a raised position. Likewise, by rotating the worm gear in an opposite direction, the circular disks are rotated in an opposite direction (e.g., counter clockwise direction), to lower the sponson .

Once the position of the sponson has been adjusted, the inertia of the motor and the gear train generally inhibit movement of the sponson relative to the sidewall . In addition, the motor (particularly in the case of a stepper-type motor) may include a self-locking feature to prevent unintentional rotation of the worm gear . In this manner, the actuator provides a locking mechanism to inhibit unintended movement of the corresponding sponson .

In the illustrated embodiment, the sponson module includes a control module for controlling the actuator . In the illustrated embodiment, the control module includes a steering input module and an engine load input module .

The steering input module is configured to detect a steering request from the operator of the watercraft , and generate a signal indicative of the steering request from the operator of the watercraft . In the illustrated embodiment, the steering angle input module comprises the handlebars and the steering sensor .

The engine load request module is configured to detect an engine load request form the operator of the watercraft and generate a signal indicative of the load request. In the illustrated embodiment, the engine load request module comprises the throttle valve position sensor .

The control module also includes a controller for receiving the signals from the steering input module and the engine load input module and for controlling the actuator in accordance with these signals. In the illustrated embodiment, the control module includes the ECU . However, the control module can alternatively be constructed of a hardwired electronic device, a dedicated processor with a memory for running one or a plurality of control routines, or general purpose processor and memory for running one or a plurality of control routines.

The control module is configured to energize the motor in accordance with signals from the steering sensor and the throttle valve position sensor . In one preferred embodiment, the control module is configured to determine if the engine load request form the operator of the watercraft is below a predetermined threshold. For example, the predetermined threshold can be a zero load request, i.e., where the operator of the watercraft has released the throttle valve, thereby allowing the engine to operate at idle speed.

Additionally, the control module is configured to determine if the operator of the watercraft desires the watercraft to turn. For example, control module can compare the output of the steering input module with a predetermined steering angle. Specifically, in the illustrated embodiment, the control module determines whether the signal from the steering sensor is greater than a predetermined threshold. The control module can be configured to actuate the motor if the throttle opening is below the predetermined threshold and if the handlebars are turned beyond a predetermined threshold. For example, but without limitation, if it is determined that the throttle valve is closed and if the handlebars are turned to the port side greater than a predetermined degree, the ECU can energize the motor to lower the sponson .

When the sponson moves to the lower most position (illustrated in phantom in FIG. 8) the hydrodynamic drag generated by the sponson is larger than that created by the sponson . The resulting increase in hydrodynamic drag on the sponson generates a torque or yaw causing the watercraft to rotate about a generally vertical axis, thereby turning the watercraft to the port side.

The control module can also be configured to return the sponson to the retracted position (solid line in FIG. 8) if either the throttle valve is opened above the predetermined threshold or the handlebars are returned to a steering angle that is less than the predetermined threshold.

Throughout the descriptions set forth above, referencing FIG. 8, only the port-side sponson was described. However, the sponson (FIG. 3) can include an actuator configured identically or substantially similarly to the actuator . Additionally, the actuator for the sponson can be connected to the ECU in the same manner as that of the actuator . As such, the control module is configured to actuate the actuator for the sponson to lower the sponson if the handlebars are turned to the starboard side beyond a predetermined threshold and if the throttle valve opening is smaller than the predetermined threshold, in a manner identical or similar to that described above with reference to the actuator .

With reference to FIG. 9, a modification to the module is illustrated therein and identified generally by the reference numeral B. Components of the module B, which are the same as the module illustrated in FIG. 8, are identified using the same reference numerals, except that a “B” has been added. These components can be the same as the corresponding components in the sponson module , except as noted below.

The module B includes a guide mechanism B that is configured to allow the sponson B to move along an arcuate fixed path between a deployed and retracted position. In the illustrated embodiment, the sponson B includes a pivot aperture . Rearward from the pivot aperture , the sponson B includes at least one arcuate guide aperture. In the illustrated embodiment, the sponson B includes a first arcuate guide aperture and a second arcuate guide aperture rearward from the aperture .

The apertures , extend through a radius of curvature having a center along the center axis of the aperture . Thus, the radius of curvature of the guide aperture is larger than the radius of curvature of the guide aperture .

A sleeve extends through each of the apertures , , . Additionally, each of the sleeves have a seat portion on the outer ends thereof. Bolts extend through each of the sleeves and into the side of the hull . Optionally, a mounting base can be used to receive the threaded ends of the bolts .

As such, the bolts and sleeves , in cooperation with the apertures , , , define the guide mechanism B which allows the sponson B to move along a fixed path between retracted and deployed positions.

The module B also includes an actuator . The actuator comprises a hydraulic supply and a hydraulic cylinder . The hydraulic cylinder includes an output shaft . A lower end of the output shaft is connected to a pivot disposed on the sponson B. In the illustrated embodiment, the pivot is disposed at an upper rear portion of the sponson B. However, other positions for the pivot can be used.

The hydraulic supply unit is connected to the cylinder with hydraulic lines , schematically illustrated in FIG. .

The control module B, in this embodiment, is configured to control the operation of the hydraulic supply . For example, when the handlebar is turned beyond the predetermined threshold, and the throttle valve opening is less than a predetermined degree, the ECU triggers the hydraulic supply to lower the sponson B. In the illustrated embodiment, the sponson B is lowered when the hydraulic supply supplies hydraulic fluid to the cylinder through the supply line . This causes a piston (not shown) inside the cylinder to be urged downwardly through the cylinder . Simultaneously, hydraulic fluid is purged from the cylinder through the hydraulic line . When the ECU signals the hydraulic supply to raise the sponson body B, the supply supplies pressurized fluid to the cylinder through the hydraulic line . Simultaneously, hydraulic fluid is purged from the cylinder through the hydraulic line . Preferably, when the sponson B is not being moved by the cylinder , valves within the supply can prevent the movement of fluid through the lines , . Thus, the output shaft remains stationary.

In operation, when the sponson B is moved downwardly through the arcuate path defined by the guide mechanism B, a portion of the sponson B is moved deeper into the water, thereby increasing the hydrodynamic drag produced by the sponson body B. Thus, as noted above, with respect to the module A, the sponson B creates a torque which turns the watercraft , as the watercraft moves through the water.

For example, as shown in FIG. 10, the sponson B is illustrated in the retracted position. After the hydraulic supply is actuated to supply fluid to the cylinder through the line , the shaft moves downwardly, thus pivoting the sponson B to the position shown in FIG. . In this position, a portion of the sponson B is moved deeper into the water as compared to the position illustrated in FIG. .

As noted above with reference to FIG. 8, when the sponson B is moved into the deployed position, the inner surface of the sponson B (corresponding to the surface of the sponson in FIG. 6) is now in contact with the body of water in which the watercraft is operating. Thus, the hydrodynamic drag of the sponson B is greater in the deployed position than that generated by the retracted position. Additionally, in the position illustrated in FIG. 11, the outwardly extending lower surface of the sponson B (corresponding to surface of the sponson in FIG. 6) is inclined with respect to the surface of the water in which the watercraft is operating. The interaction of this now inclined surface against the body of water further enhances the hydrodynamic drag generated by the sponson B.

With reference to FIG. 12, a modification of the module B is illustrated therein and is identified generally by the reference numeral C. The components of the module C corresponding to the same or similar components of the module B are identified using the same reference numerals. These components can be considered to be identical or similar to the components of the module B, except as noted below.

In the module C, the sponson C includes teeth along a rearward edge of the sponson C.

The module C includes an actuator C. The actuator C includes a motor C driving an output shaft C. A gear is connected to the outer end of the shaft C. The teeth of the gear are configured to mesh with the teeth on the sponson C. Preferably, the motor C is mounted within the hull . Additionally, at least one seal defining a through hole fitting provides a substantially water-tight seal with the shaft C extending therethrough. The motor C and the shaft C are mounted such that the gear meshes with the teeth .

In operation, when the handlebar is turned beyond its predetermined degree toward the port side, and when the opening of the throttle valve is below a predetermined degree, the ECU actuates the actuator C to lower the sponson C. For example, the ECU can drive the motor C such that the shaft C rotates in a counterclockwise direction, as viewed in FIG. . Thus, through the interaction of the gear with the teeth , the rear portion of the sponson C is pivoted downwardly to the position of the sponson B illustrated in FIG. . As noted above with respect to the motor illustrated in FIG. 8, the motor C can be an electric stepper motor and, optionally, can include a self-locking feature. Thus, the sponson C can be held rigidly in the positions including in-between a fully retracted position and a fully deployed position.

FIG. 13 illustrates another modification of the sponson module A and is identified generally by the reference numeral D. The components of the module D which are the same or similar to the components of any of the modules A-C, are identified with the same reference numeral, except that a “D” has been added thereto.

The sponson D is similar to the sponsons , B, C. However, the sponson D preferably includes recesses , on its inner surface D. Advantageously, the recesses , are configured to accommodate components of the guide mechanism D.

In the illustrated embodiment, the recesses at the forward and rearward portion of the inner surface D, are configured to accommodate portions of he guide mechanism D which define the fixed path along which the sponson D travels, discussed in greater detail below.

The guide mechanism D comprises front and rear multi-link assemblies , . Preferably, the multi-link assemblies , comprise a plurality of pivoting members defining a scissor-type link mechanism. Preferably, the assemblies , are configured to define a fixed path between retracted and deployed positions of the sponson D. For example, the assemblies , can be constructed similarly to a scissor jack assembly, or a pantograph-type assembly.

The guide mechanism D, in the illustrated embodiment, is configured to guide the sponson D along a path that is generally perpendicular to the sidewall of the hull . However, the guide mechanism D can be configured to guide the sponson D along a different path.

The actuator C is connected to the sponson D at a mounting boss . The mounting boss preferably is disposed in the recess .

The output shaft D extends through an aperture defined in the side of the hull . A seal defines a substantially water tight through hole fitting for the shaft D.

A mounting bracket is also connected to the side wall . Additionally, the mounting bracket supports the cylinder D relative to the side .

In operation, when the control module D receives a signal from the steering input module D that the operator intends to turn, and receives a signal from the engine load request input device D that the engine load request is below a predetermined threshold, the control module D causes the sponson D to move to a deployed position. For example, the ECU can actuate the hydraulic supply to supply fluid to the cylinder through the supply line D. As such, the shaft D extends outwardly from the side wall and thus urges the sponson D to a deployed position.

FIG. 15 illustrates the deployed position of the sponson D. In this position, the inner surface D of the sponson D is moved away from the side surface . Thus, the hydrodynamic resistance caused by the sponson D increases. Additionally, because the sponson D moves in a direction laterally away from the side wall , the moment arm of the torque imparted to the watercraft is increased. This further enhances the torque imparted upon the watercraft , and thus enhances the steering effect provided by the module D.

With reference to FIG. 16, a modification of the sponson module D is illustrated therein identified generally by the reference numeral E. Components of the module E, which are the same or similar to the module D, are identified with the same reference numeral. The construction and operation of the components with the same reference numeral can be identical or similar to the corresponding components in the module D, except as noted below.

The sponson E is similar to the sponson D illustrated in FIG. . However, the sponson E does not include the recess of the sponson D.

The actuator E of the module E is a magnetic actuator. The actuator E is configured to move the sponson E between the retracted and deployed positions with a magnetic field.

Preferably, the actuator E includes an electromagnet and a permanent magnet . In the illustrated embodiment, the electromagnet is mounted to an inner side of the lateral side of the hull . The permanent magnet is mounted within the sponson E.

The electromagnet is configured to be selectively operable so as to either attract the permanent magnet or repel the permanent magnet . Thus, when the electromagnet is energized to attract the permanent magnet , the sponson E moves toward and is fixed in place against the lateral side of the hull . On the other hand, when the electromagnet is energized to repel the permanent magnet , the sponson E moves toward the deployed position and is thus held there by the repulsion force between the electromagnet and the permanent magnet .

This design provides a further advantage in that no through hole fitting is used for the actuator E. Thus, there are fewer water-tight seals needed for the module E.

With reference to FIG. 17, a control routine for controlling the movement of the sponsons , B, C, D, E is illustrated therein and is identified generally by the reference numeral . At the block B, the routine begins. For example, the routine can begin whenever the main power switch for the engine is on. Optionally, the routine can begin whenever the engine is running. After the block B, the routine moves on to a block B.

At the block B, an engine load request To is determined. For example, the output of the throttle position sensor can be sampled. In the watercraft , where the throttle valve is connected directly to a throttle lever with a direct mechanical connection, the engine load request is the same as the throttle position. After the block B, the routine moves on to a block B.

At the block B, it is determined whether the engine load request Tθ is less than or equal to a predetermined engine load request Tp. For example, the engine load request Tθ can be compared to a predetermined engine load request Tp. In a preferred embodiment, the predetermined load request Tp is zero, which corresponds to a situation where the throttle lever mounted on the handlebar is not depressed by an operator. Thus, the engine is either idling or stopped. However, other predetermined engine load requests can be used. If the engine load request Tθ is not less than or equal to the predetermined engine load request TP, the routine returns to block B and repeats. If, however, the engine load request Tθ is less than or equal to the predetermined engine load request Tp, the routine moves on to a block B.

At the block B, a steering angle Sθis determined. For example, the output of the steering angle sensor can be sampled. After the block B, the routine moves on to a block B.

At the block B, it is determined whether the steering angle Sθ is greater than or equal to a predetermined steering angle SP. For example, the sampled steering angle Sθ can be compared to the predetermined steering angle SP. If it is determined that the steering angle Sθ is not greater than or equal to the predetermined steering angle SP, the routine returns to block B and repeats. However, if the steering angle Sθ is greater than or equal to the predetermined steering angle SP, the routine moves on to a block B.

At the block B, it is determined whether the steering angle indicates a port or starboard direction. For example, as noted above, the steering angle sensor can include a switch to determine whether the handlebar is turned toward the port or starboard side. If it is determined the steering angle is toward the starboard side, the routine moves to a block B.

At the block B, the corresponding sponson module A, B, C, D, E is controlled to deploy the starboard sponson. After the block B, the routine moves on to block B and ends. Optionally, the routine can return to the block B and begin again after the Block B.

With reference to the block B, if it is determined that the steering angle is not toward the starboard side, the routine moves to a block B.

At the block B, the port side sponson is deployed. After the block B, the routine moves to the block B and ends, as noted above.

In the illustrated embodiment, the routine is in the form of a computer program stored on a computer-readable medium within the ECU . The ECU can include, as noted above, a general purpose processor and a memory for storing and running one or a plurality of computer programs, such as the routine . Optionally, the ECU can include one or a plurality of dedicated processors and corresponding memories for storing and running one or a plurality of a computer programs, such as the routine . The routine , optionally, can be constructed as a hard wired system incorporated into the ECU.

Of course, the foregoing description is that of certain features, aspects and advantages of the present invention to which various changes and modifications may be made without departing from the spirit and scope of the present invention. A watercraft need not feature all objects of the present invention to use certain features, aspects and advantages of the present invention. The present invention, therefore, should only be defined by the appended claim.

CLAIMS

1. A watercraft comprising a hull, an engine supported by the hull and having an output shaft, a propulsion device connected to the output shaft of the engine, a steering input device configured to be manually operable by an operator, a steering device configured to steer the watercraft in accordance with the position of the steering input device, first and second sponson modules connected to opposite sides of the hull, each sponson module comprising a sponson body having a first inner surface facing toward a side of the hull, a second lower surface extending from the inner surface away from the hull, and a third surface extending at an angle from the second surface and being spaced outwardly from the first inner surface, each sponson module also including a guide mechanism defining a fixed path of travel for each sponson body between a first retracted position and a second deployed position, a steering sensor configured to detect a position of the steering input device and to generate a position signal indicative of the position of the steering input device, an actuator for moving the sponsoring body between the first and second positions, and a controller configured to control the actuator based on the position signal from the steering sensor.

2. A watercraft according to claim 1, when the propulsion device comprises a jet pump, the steering device comprising a steering nozzle pivotally mounted at an outlet of the jet pump.

3. A watercraft comprising a hull, an engine supported by the hull, a power request input device positioned for operation by an operator of the watercraft, a steering input device mounted to the hull and configured for pivotal movement between port and starboard directions, port and starboard side sponsons, a controller configured to move the port and starboard sponsons relative to the hull between a retracted position and a deployed position, the controller being configured to deploy the port side sponson when the steering input device is turned toward the port side, and a power request sensor configured to detect a position of the power request input device and to generate a signal indicative of the position of the power request input device, wherein the power request input device is configured to move through first and second ranges of movement, the controller being configured to deploy the sponsons only if the request input device is within the first range of movement.

4. The watercraft according to claim 3, wherein the first range of movement corresponds to a first range of power output of the engine, the second range of movement corresponding to a second range of power output of the engine greater than the first range.

5. A watercraft comprising a hull, a power request device configured for operation by an operator of the watercraft, a steering input device configured for operation by an operator of the watercraft and for pivotal movement, at least a first sponson mounted for pivotal movement relative to the hull, a controller configured to control movement of the first sponson between retracted and deployed positions in response to pivotal movement of the steering input device and to determine if the power request device is suddenly released, wherein the controller is further configured to move the first sponson to the deployed position only when the watercraft is operating in a body of water at a planing speed, the power request device is suddenly released and at the same time, the steering input device is turned, the deployed position of the first sponson being configured such that the first sponson contacts the body of water sufficiently to cause the watercraft to turn at least ninety degrees before the watercraft coasts to a stop.

6. The watercraft according to claim 5 wherein the first sponson comprises a first surface juxtaposed to the hull of the watercraft and a second surface extending from the first surface away from the hull the watercraft, the first sponson being mounted to pivot between a retracted position and a deployed position such that in the deployed position, the second surface is skewed sufficiently relative to a surface of a body of water to generate yaw.

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