Patent Application
20090197486
The present invention concerns methods of maneuvering aquatic vessels, for example boats. Moreover, the present invention also relates to aquatic vessels operable pursuant to such methods. Furthermore, the present invention also concerns software products stored on a data carrier or conveyable by a way of a signal, wherein the software products are executable on computing hardware for implementing methods of the invention.
Motorized aquatic vessels such as boats are well known. With regard to competition speed boats, high performance fishing boats and similar types of aquatic vessels for which responsive handling characteristics are highly desirable, methods of providing such boats and vessels with an enhanced degree of maneuverability is highly desirable. For example, when using motorized boats for fishing large sport fish, for example sharks, tuna, or marlins and other billfish, it is highly desirable that the boats can be turned rapidly substantially about their geometrical center. This allows the stern regions of the boats, where fishing apparatus such as booms and winches are conventionally mounted, to be maneuvered towards the fish to assist with capturing such fish and eventually winching them onboard the boats.
Although more powerful boat engines are perceived to be capable of rendering boats more rapidly maneuverable, for example for catching large fish, such larger engines weigh more and tend to offset performance benefits of more powerful engines. Moreover, larger engines can potentially result in high center of gravity for boats which adversely affects their stability in water.
Referring to
The illustrated exemplary boat 10 has a length L on the order of 12 meters; the boat 10 is referred to colloquially as being a “40-foot” boat. The drive units 30, 50 are mounted a distance d2 apart, wherein the distance d2 is on the order of 1.5 meters for the boat 10. Moreover, the drive units 30, 50, in a longitudinal direction along the boat 10, are mounted a distance d1 from the aforementioned geometrical center C, wherein the distance d1 is on the order of 3.5 meters to 4 meters for the boat 10. However, the boat 10 can be of other physical dimensions.
The boat 10 further includes a control unit 70 coupled in communication with the engines and drive units 30, 50 for controlling gear shift, engine power and angular orientation of the rudders 34, 54 relative to the hull 20. Gear shift control involves engaging in forward, reverse or neutral. The control unit 70 is also coupled in communication with a steering console 80 from which user operation commands are provided to the control unit 70. The steering console 80 includes a user-rotatable steering wheel 90 and a lever arrangement 100. The steering wheel 90 is coupled to a rotation sensor which senses an angular position of the wheel 90 to generate a steering command signal for transmission to the control unit 70. The lever arrangement 100 includes one or more levers for controlling average power delivered by the engines to their propellers 32, 52, and for commanding gear shifts for the drive units 30, 50.
Operation of the boat 10 will now be described to place the present invention into context. When the boat 10 is being driven by its user in a forward direction, that is, straight ahead, both engines are commanded by the user via the steering console 80 to deliver substantially equal power to their propellers 32, 52, respectively. The propellers 32, 52 are of nominally similar size and design and both propellers 32, 52 contribute to provide a backward directed thrust for propelling the boat 10 in the forward direction. Moreover, the engines are also preferably of similar design and size. Additionally, both drive units 30, 50 are implemented so that the propellers 32, 52 respectively rotate in mutually opposite directions so as not to cause any bias in a forward path of the boat 10. For the forward direction, the rudders 34, 54 are adjusted using the steering wheel 90 to be substantially aligned to the axes 40, 60 respectively.
When the user desires to steer the boat 10 in a gradual manner from such a forward path to implement a relatively wide turn, the user rotates the steering wheel 90 which results in commands being transmitted to the control unit 70 which, in consequence, causes actuators associated with the rudders 34, 54 to pivot the rudders 34, 54 in synchronism, for example as illustrated in
When the boat 10 is being used to hunt big fish, the boat 10 is typically operated with a first person at the steering console 80 steering the boat 10 and a second person at the stern region for operating winches and similar apparatus for landing the big fish onboard the boat 10. Because big fish are physically strong, it is desirable that the first person or pilot controls orientation of the boat 10 promptly in relation to the big fish otherwise there is a risk that the big fish would cause the boat to roll over on its side with an associated risk of capsizing or sinking. The pilot attempts to maneuver the boat 10 so that the stern region of the hull 20 faces towards the big fish which largely prevents the boat 10 from rolling laterally to port-side or starboard as the big fish struggles.
One form of maneuver which is especially beneficial when attempting to catch big fish is to try to maintain the big fish on a port-side/stern of the boat 10 while turning the boat 10 substantially about its geometric center C. Such a turn will be referred to as a “tight left” turn. Such a tight left turning maneuver is achieved by using the lever arrangement 100 to shift the first drive unit 30 into reverse and the second drive unit 50 into forward gear. In such a mode of operation, the propellers 32, 52 rotate in a mutually similar direction. In consequence the propeller 32 develops longitudinal and lateral components of thrust 120, 140 respectively as illustrated in
Similar considerations pertain when a tight right turn is required wherein the first drive unit 30 is configured in a forward gear and the second drive unit 50 is configured in a reverse gear for causing the boat 10 to rotate in a clockwise manner about the geometrical center C.
Such a combination of both lateral and rotation movement of the boat 10 is regarded by expert fishermen to be highly desirable for maintaining a struggling big fish at a stern of the boat 10.
More recently, dual counter-rotating duo-prop propellers, for example in a manner as described in a published international PCT patent application no. WO 2004/074089 (PCT/SE2004/000206) (Volvo Penta AB), have become popular in that, for a given size of propeller assembly, they are capable of generating more thrust. Such counter-rotating propellers are either configured in pushing mode or in traction mode depending upon implementation.
The boat 10 in
When performing a tight left turn about the geometrical center C as illustrated in
It is thus desirable to try to employ counter-rotating duo-prop propellers in the boat 300 simultaneously with achieving a lateral component of thrust when performing tight turns. Lack of such a lateral component represents a technical problem which the present invention seeks to address.
An object of the present invention is to provide a method of maneuvering aquatic vessels which provides a beneficially useful combination of rotational movement and lateral sideways lateral movement.
According to a first aspect of the invention, there is provided a method of maneuvering an aquatic vessel,
the vessel including at least one hull and at least one engine, the at least one engine including at least one output rotationally couplable to a plurality of corresponding propeller units having drives which are mounted so as to be angularly moveable with respect to the at least one hull, the aquatic vessel including a control unit for controlling operation of the at least one engine and angles of the propeller units with respect to the at least one hull, the aquatic vessel being configurable to operate in a first mode wherein directions of thrust developed by the plurality of propeller units are mutually substantially parallel for propelling the vessel through water,
the method including steps of:
The invention advantageously configures the propelling units in such a divergent manner which provides both a rotational and lateral movement of the vessel when operated in the second mode which, for example, is beneficial when hunting for big fish.
Optionally, the method includes a step of orientating the propeller units so that their thrust directions are divergent in the second mode by a divergence angle in a range of 5° to 45° with respect to the longitudinal axis of the vessel passing from its rear end to its forward end. Such a range of angles provides a useful degree of rotation and lateral motion of the vessel when configured in its second mode of operation.
Alternatively, the divergence angle is in a range of 8° to 30° in respect of the longitudinal axis. Yet another alternative is to set the divergence angle in a range of 25° to 28° with respect to the longitudinal axis. A particularly advantageous divergence angle is substantially 26° with respect to the longitudinal axis.
Advantageously, when implementing the method, each propeller unit is coupled to an associated dedicated engine which is independently user controllable in the second mode. Such implementation is highly convenient for obtaining a low center of gravity for the vessel as well as being mechanically more convenient in its implementation; for example, two smaller engines are individually of potentially lower weight than one single larger engine offering similar power output.
Optionally, the method includes a step of user-selecting amongst a plurality of permitted divergent angles for the propeller units via the control unit in the second mode. The user is thereby capable of selecting a divergence angle with which the user is most comfortable.
Optionally, in the method, at least one of the plurality of propeller units is configured to be a dual counter-rotating propeller arrangement. Such dual propellers operable to mutually counter rotate in operation are capable of providing higher magnitudes of thrust for a given propeller size in comparison to single-propeller units.
Optionally, the method is implemented so that the vessel is rotatable substantially about its geometrical center simultaneously with a stern region of the vessel being movable in a lateral direction.
Optionally, according to the method, the plurality of propeller units are orientated so as to be substantially angularly symmetrically disposed about the longitudinal axis when adjusted to be angularly divergent.
Optionally, the method includes a step of coupling a user-operable joy-stick type control in communication with the control unit for controlling operation of the propeller units coupled to the at least one engine in the second mode. Such joy-stick type control is advantageous when quick maneuvering is needed.
Optionally, the method includes a step of coupling a plurality of mutually independently user-adjustable lever controls to the control unit, the plurality of lever controls being operable via the control unit to control power coupled from the at least one engine to their corresponding propeller units. Such lever control is found in practice to be highly user-ergonomic and provides a fine degree of control of the vessel.
Optionally, in the method, the second mode is a “fishing” mode adapted for providing the vessel with a turning characteristic suitable for invoking when the vessel is to be used to catch big fish.
According to a second aspect of the invention, there is provided an aquatic vessel,
the vessel including at least one hull and at least one engine, the at least one engine comprising at least one output rotationally couplable to a plurality of corresponding propeller units which are mounted so as to be angularly moveable with respect to the at least one hull, and a control unit for controlling operation of the at least one engine and angles of the propeller units with respect to the at least one hull, the aquatic vessel being configurable to operate in a first mode wherein directions of thrust developed by the plurality of propeller units are mutually substantially parallel for propelling the vessel through water, and a second mode of operation wherein the directions of thrust developed by the propeller units are configured to mutually diverge in respect of a longitudinal axis from a rear end of the vessel to a forward end thereof for providing the vessel with a turning characteristic in operation, wherein
Optionally, the propeller units of the aquatic vessel are operable to be orientated so that their thrust directions are divergent in the second mode by a divergence angle in a range of 5° to 45° with respect to a longitudinal axis of the vessel passing from its stern to its forward end.
Alternatively, the divergence angle is in a range of 8° to 30° with respect to the longitudinal axis. Yet another alternative is that the divergence angle is in a range of 25° to 28° in respect of the longitudinal axis. Further, and advantageously, the divergence angle is substantially 26° in respect of the longitudinal axis.
Optionally, in the aquatic vessel, each propeller unit is coupled to an associated engine which is mutually independently user controllable in the second mode.
Optionally, in the aquatic vessel, the plurality of permitted divergent angles for the propeller units are user-selectable via the control unit in the second mode.
Optionally, in the aquatic vessel, at least one of the plurality of propeller units is configured to be a dual counter-rotating propeller arrangement.
Optionally, the vessel in operation is rotatable substantially about its geometrical centre simultaneously with a stern region of the vessel being movable in a lateral direction.
Optionally, the aquatic vessel is implemented such that the plurality of propeller units are orientated so as to be substantially angularly symmetrically disposed about the longitudinal axis when adjusted to be angularly divergent.
Optionally, the aquatic vessel further includes a user-operable joy-stick type control coupled to the control unit for controlling operation of the propeller units coupled to the at least one engine in the second mode.
Optionally, the aquatic vessel is implemented such that a plurality of mutually independently user-adjustable lever controls are coupled to the control unit, the plurality of lever controls being operable via the control unit to control power coupled from the at least one engine to their corresponding propeller units.
Optionally, the aquatic vessel is implemented such that the second mode is a “fishing” mode adapted for providing the vessel with a turning characteristic suitable for invoking when the vessel is to be used to catch big fish, for example mature sharks.
According to a third aspect of the invention, there is provided a software product recorded on a data carrier or conveyable via a signal, the software product being executable on computing hardware of a control unit for implementing a method pursuant to the first aspect of the invention.
According to a fourth aspect of the invention, there is provided propulsion system for an aquatic vessel, the propulsion system being operable according to a method pursuant to the first aspect of the invention.
It will be appreciated that features of the invention are susceptible to being combined in any combination without departing from the scope of the invention as defined by the accompanying claims.
Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings wherein:
a and 4b are illustrations of implementations of a joy-stick control suitable for steering the boat of
In a boat as configured in
The boat 500 of
When the “fishing mode” control 520 is invoked, the control unit 70 commands the drive units 330, 350 to pivot from a substantially synchronized angular configuration wherein thrusts developed therefrom are in mutually substantially parallel directions, to a divergent angular configuration as depicted in
Beneficially, the control unit 70 steers the drive units 330, 350 in the aforesaid “fishing” mode so that the angles α1, α2 are substantially mutually similar in magnitude. Optionally the angles α1, α2 are in a range of 5° to 45°, more preferably in a range of 8° to 30°, and most preferably in a range of 15° to 28°, for example, substantially 260. As illustrated in
a setting “A” corresponding to α1=−α2 (normal non-fishing mode, namely “fishing” mode deactivated such that thrusts developed by the propellers 332, 352 are developed in directions which are mutually parallel);
a setting “B” corresponding to α1, α2=5° (namely the engines 30, 50 are configured to be divergent as illustrated in
a setting “C” corresponding to α1, α2=10° (the engines 30, 50 being divergent as in
a setting “D” corresponding to α1, α2=18° (the engines 30, 50 being divergent as in
a setting “E” corresponding to α1, α2=26° (the engines 30, 50 being divergent as in
Alternatively, the control 520 can be continuously variable and the angles α1, α2 servo controlled accordingly to continuous adjustment of the control 520.
In operation in “fishing” mode, as illustrated in
Similar considerations pertain when, in “fishing” mode, the first drive unit 330 is engaged in forward gear and the second drive unit 350 is engaged in reverse gear causing the boat to move laterally to a left-hand side of
The “fishing” mode is thus capable of providing movement as obtained for the boat 10 illustrated in
When implementing the system in a boat 500, its length L is preferably in a range of 8 metres to 20 metres, more preferably in a range of 10 metres to 15 metres, and most preferably substantially 12 metres. The boat 500 optionally has a length corresponding to a boat colloquially known as a “40-foot” boat. The distance d2 between the drive units for the boat 500 is preferably in a range of 1 meter to 3 meters, more preferable in a range of 1.2 meters to 2 meters, and most preferably substantially 1.5 meters. Moreover, the distance d1 from the center to the drive units for the boat 500 as illustrated in
Optionally, the steering console 80 is provided with the steering wheel 90 and its associated control arrangement 100, as shown in
An end knob 620 at a distal end of the joystick 610 as illustrated is user-rotatable as denoted by an arrow 630. Rotation of the knob 620 is used to control a difference in power ΔP delivered by each engine. Advantageously, rotation of the knob 620 is spring biased so that the knob 620 returns to a central rotational position corresponding to substantially zero difference in power ΔP when the user does not apply any rotational force thereto. When a relatively larger rotation is applied to the knob 620, it can, for example in an extreme case, result in one of the drive units 330, 350 being engaged into forward gear and another of the drive units being engaged into reverse gear to provide the boat 500 with impressive turning and sideways movements in operation.
The joystick control illustrated in
Referring next to
It will be appreciated that the boat 500 can be provided with a steering wheel in a manner akin to
Although the present invention has been described in the foregoing in respect of the boat 500 used for catching large fish, the present invention is not limited to use in such a configuration and can be adapted for use with other types of aquatic vessels, for example naval vessels, gunboats and such like. The aforesaid “fishing” mode is also useful when maneuvering the boat 500 in tight confines, for example a crowded harbor, when maneuvering the boat for tethering or un-tethering. Moreover, the present invention is also useful for controlling boats in rough seas when approaching other objects, for example in respect of offshore oil exploration and pilot boats. Modifications to embodiments of the invention described in the foregoing are thus possible without departing from the scope of the invention as defined by the accompanying claims.
The present invention is not limited for use with aquatic vessels having only a single hull. The present invention can be also employed with multi-hulled boats, for example catamaran and trimaran type performance boats. Although two engines and drive units are described, the boat 500 optionally utilized other numbers of engines, for example a single engine couple via dual transmissions to the propeller units 332, 352.
Expressions such as “including”, “comprising”, “incorporating”, “consisting of”, “have”, “is” used to describe and claim the present invention are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural.
Numerals included within parentheses in the accompanying claims are intended to assist understanding of the claims and should not be construed in any way to limit subject matter claimed by these claims.
