The subject matter is related to bow and stern thrusters for recreational boaters.
Bow and stern thrusters are a common piece of equipment on many boats. They provide the necessary thrust to change the yaw direction of a boat in tight quarters. In many instances the presence of wind or current in a tight marina makes safe handling of some boats nearly impossible without a thruster.
However, conventional thrusters come at a price. They are expensive to purchase and very expensive to install. Typically, the boat hull most be modified to add a “tunnel” through the boat where the thruster propeller is located and the thrusted water flows. Power must be routed to the thruster to provide the high current requirements. Finally, control devices and wiring must be installed from the helm to the bow thruster. Since much of this work is below the water line, the boat must be hauled out of the water.
The tunnel and thruster components add to the hydraulic drag of the boat. To reduce this drag the hulls are often further modified to fair the hull leading into the tunnel opening.
The resulting configuration creates new opportunities for hull leaks and exposes the thruster components to corrosion, fouling from marine life, and catching seaweed and other floating debris. Since the thruster components are underwater and inaccessible they are difficult to clean and maintain without hauling the boat out of the water periodically.
There are existing alternatives to the common tunnel thruster just described. These alternatives address the key issue of having to cut holes in the hull of the boat for the tunnel, but not the other issues. Further, they create additional problems.
One alternative is to mount a “pod” to the bottom of the keel. This pod has a small tunnel through it with a propeller in the tunnel. This eliminates the need for cutting holes in the hull of the boat for placing a thruster tunnel, although it is usually required to modify the hull to fair the pod with the hull. The boat must still be hauled out of the water to drill the mounting holes for the pod, and run the power and control wires through the hull. Furthermore, the thruster is still subject to corrosion and fouling and must be hauled out periodically for cleaning. Importantly, the pod creates more drag than the traditional tunnel approach and renders the thruster vulnerable to damage from strikes from floating debris (such as logs) or from groundings.
A second alternative is to bolt a thruster unit to the front of the bow below the water line. This also eliminates the need for cutting holes in the hull of the boat for placing a thruster tunnel, but it does not address the other issues raised. The boat still needs to be hauled out of the water to drill the underwater mounting holes and to run the power and control cables. This second alternative is not very popular due to the sizeable drag created by its externally bolted structure, and the vulnerability to damage from floating debris, ground strikes, and trailering.
As useful as bow and stern thrusters are, the negatives prevent many boat owners from outfitting them on their boats. This is particularly true of sailboat owners who cannot afford the increased drag created by conventional bow thrusters.
In one or more embodiments, a thruster apparatus for use with a boat at either the stern or bow is described herein. The thruster apparatus includes one or more electric motors operatively coupled with one or more propulsion devices, the one or more electric motors configured to drive one or more propulsion devices. The apparatus further includes at least one power source coupled with the electric motors, the at least one power source configured to provide power for the one or more electric motors. An electrical controller is configured to receive a wireless signal, the controller configured to control power to the electric motors based on the signal. A thruster unit housing is provided with the apparatus and contains the one or more motors with propulsion devices, electrical controller, and the at least one power source. The apparatus further includes a sliding car coupled with the thruster unit housing, one or more hull attachment fixtures mounted to the hull of the boat with at least one hull attachment fixture mounted near a water line, and a guide device coupled with one or more hull attachment fixtures, the guide device configured to guide the sliding car up and down.
In one or more embodiments, the guide device is a track.
In one or more embodiments, the thruster unit housing and sliding car mechanism can be removed from the track once the thruster unit housing is raised to a deck allowing for the removal of the thruster unit housing from the hull of the boat.
In one or more embodiments, the guide device is a guy line and at least one of the one or more hull attachment fixtures has a guide rail that engages with the sliding car as the sliding car slides down along the guy line.
In one or more embodiments, the thruster unit housing and sliding car are removably coupled with the guy line.
In one or more embodiments, the thruster unit housing and the sliding car are coupled together into a single assembly.
In one or more embodiments, wherein the at least one power source includes one or more batteries.
In one or more embodiments, a thruster apparatus for use with a boat is described herein. The thruster apparatus includes one or more electric motors operatively coupled with one or more propulsion devices, the one or more electric motors configured to drive one or more propulsion devices. The apparatus further includes at least one power source coupled with the electric motors, the at least one power source configured to provide power for the one or more electric motors. An electrical controller is configured to receive a wireless signal, the controller configured to control power to the electric motors based on the signal. A thruster unit housing is provided with the apparatus and contains the one or more motors with propulsion devices, electrical controller, and the at least one power source. The apparatus further includes a means for guiding the thruster unit housing up and down a hull of the boat.
In one or more embodiments, the means for guiding the thruster unit housing includes a sliding car coupled with the thruster unit housing, the sliding car slideably coupled with a guide device mounted on the hull.
In one or more embodiments, the guide device is a track.
In one or more embodiments, the thruster unit housing and sliding car mechanism can be removed from the track once the thruster unit housing is raised to a deck allowing for the removal of the thruster unit from the hull of the boat.
In one or more embodiments, the guide device is a guy line and at least one of the one or more hull attachment fixtures has a guide rail that engages with the sliding car as it slides down along the guy line.
In one or more embodiments, the thruster unit housing and sliding car are removably coupled with the guy line.
In one or more embodiments, the thruster unit housing and the sliding car are coupled together into a single assembly.
In one or more embodiments, the at least one power source includes one or more batteries.
In one or more embodiments, a method for using a thruster apparatus with a boat is provided herein. The method includes providing power from at least one power source to one or more electric motors, sending a wireless signal from a transmitter to an electrical controller that receives the wireless signal and controls power to the one or more electric motors based on that signal, driving one or more propulsion devices with the one or more electric motors, where a thruster unit housing contains the one or more motors, the electrical controller, and the at least one power source. The method further includes sliding a sliding car along a guide device, where the sliding car is coupled with the thruster unit housing, and the guide device is coupled along a hull of the boat with one or more hull attachment fixtures.
In one or more embodiments, sliding the sliding car on the guide device includes sliding the sliding car on a track.
In one or more embodiments, the method further includes removing the thruster unit housing and sliding car mechanism from the track once the thruster unit housing is raised to the deck.
In one or more embodiments, the thruster unit housing and sliding car can be removed from the guy line once raised to the deck allowing for the removal of the thruster unit from the hull of the boat.
These and other embodiments, aspects, advantages, and features of the present invention will be set forth in part in the description which follows, and will become apparent to those skilled in the art by reference to the following description of the invention and referenced drawings or by practice of the invention. The aspects, advantages, and features of the invention are realized and attained by means of the instrumentalities, procedures, and combinations particularly pointed out in the appended claims and their equivalents.
An understanding of the apparatus and methods will now be had upon reference to the following detailed description, when read in conjunction with the accompanying drawings, where like reference characters refer to like parts throughout the several views, and in which:
The following detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the apparatus may be practiced. These embodiments, which are also referred to herein as “examples” or “options,” are described in enough detail to enable those skilled in the art to practice the present embodiments. The embodiments may be combined, other embodiments may be utilized or structural or logical changes may be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense and the scope of the invention is defined by the appended claims and their legal equivalents.
In this document, the terms “a” or “an” are used to include one or more than one, and the term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation.
An electric bow or stern thruster system must have a motor with a means of propulsion, a source of electrical power, a means for control, and a means for attaching to the boat. The present invention integrates all of these functions of a bow or stern thruster into a self-contained unit. This allows for mounting schemes that provide for secure attachment to the boat while allowing for retraction of the thruster, or even removal from the hull for storage.
A bow or stern thruster requires a tremendous amount of power for a relatively short period of time. However, it is only used to control the boat during docking and undocking maneuvers. It sits idle while at dock and while underway. The present invention takes advantage of this low duty cycle, high discharge usage by employing modern high power (watts), low capacity (joules) batteries. Lithium Iron Phosphate (LiFePo) batteries, for example, exist that can provide 100 Amps of power yet are only 1.5 inches in diameter. Four of these batteries in series provide 12 volts, suitable for driving thruster motors. These batteries can provide sufficient power to drive one or more thruster motors for a period of 5 to 15 minutes. This is more than enough time to support an undocking and a subsequent docking maneuver before having to be recharged.
The present invention uses modern high power batteries that are compact enough to be integrated into the thruster unit housing along with one or more motors, along with electronic circuitry to receive the wireless command signals and process them to control the current flowing into the one or more motors. The invention also includes a means for activating the thruster unit and a means for recharging the batteries when not in use.
A key feature of the invention is the ability to deploy the thruster unit such that the one or more motors are sufficiently below the water line, and then to retract the thruster unit up out of the water. The thruster unit can even be removed completely from the hull since there are no electrical connections tethering it to the boat.
In one or more embodiments, a track is included that the thruster unit rides on. A tether line attached to the thruster unit can be pulled to retract the thruster unit or let out to deploy the unit. By sliding the thruster unit all the way off the top-side of the track the unit can be removed from the hull. A “T-track”, for example, is a conventional piece of sailboat hardware that allows a car to slide along the T-track. The term “car” is borrowed from conventional sailboat hardware terminology and is used here to refer to a hardware component that slides along a track or a guy line. This form of mounting provides a very robust mounting scheme once the car is held fast on the track. Some embodiments of the invention use the weight of the thruster unit to hold the car securely at the bottom of the track while deployed, and use a tether line attached to the car or to the thruster unit to hold the car securely to the top of the track while retracted.
One or more embodiments include a guy line wire for the car to ride along. The guy line, for example, can be a wire, rope, or rod and is anchored to the bow of the boat near the water line and is further secured near the deck of the boat. The car rides up and down along this guy line by using a tether attached to the car or to the thruster unit. The car can be removed from the guy line by removing locking pins or other suitable attachment devices holding the car to the guy line.
In one or more embodiments the thruster unit can slide along the car itself. Thus, the car can be raised and lowered relative to the boat while the thruster unit can be further raised above the end of the track or guy line to increase the stowed position clearance to the sea. This is particularly useful in rough seas.
It should be understood that there are many variants to how the thruster unit gets deployed and retracted. For example, by providing slack to the guy line it would be possible to haul the thruster unit and/or car completely up onto the deck. Another variant would be to extend the track or guy line above the deck to allow retracting the thruster completely above the deck.
The term “thruster unit” is used to describe a mechanically sturdy apparatus consisting of a battery, a propulsion motor, a radio receiver, control logic, and power driver circuitry.
The term “propulsion” is used to describe any number of means for converting electrical power into mechanical hydraulic thrust. This can be a propeller, a pump, or a water jet for example.
The term “integrated” is used to describe an assemblage of parts in close proximity. This can be in one or more housings that are generally mechanically attached together.
The term “sliding car” or “car” is used to describe a mechanical device that slides along a track or guy line in substantially a linear motion. This mechanical device does not need to be a separate unit such that the sliding guide function of the “car” may be integrated into the thruster unit housing.
The term “guy line” is used to describe a generally straight mechanical device that can be a rope, a wire, a rod, a bar, or any similar structurally strong material.
The term “guide device” is used to describe a mechanical device such as a track, a bar, a rope, a wire, or a rod that guides the travel of a sliding car along a predominately linear path.
The term “hull attachment fixture” is used to describe a device for firmly attaching a guide device to the hull of a boat. This can be as simple as a bolt or could be more complicated to include alignment features. In some embodiments only one hull attachment fixture is used. In this case, the hull attachment fixture would be mounted near the water line of the hull. In other embodiments additional hull attachment fixtures are used. In this case, some of the hull attachment fixtures could be mounted on the hull near the deck of the boat.
The term “guide rail” is used to describe a mechanism for aligning the sliding car to a hull attachment fixture, and may be part of the hull attachment fixture. In some embodiments the guide device does not fully constrain the motion of the sliding car. A guy line, for example, does not constrain the car from rotating about the guy line. Nor does it prevent the car from torqueing the guy line to roll or pitch with respect to the hull. To constrain the motion of the car, with the exception of the freedom to move along the length of the guy line, a guide rail is used that engages with the car as it is lowered to the water line. The term “guide rail” is used broadly to include any mechanical means for engaging with the car and constraining its motion in all directions except along the length of the guide device.
Further detailed description of these and other embodiments is provided below.
It should be noted that the end result of raising motor 106 well above the water line could also be achieved, for example, by extending track 302 above the deck of bow 304 or by pivoting thruster unit 101 relative to car 301.
In the embodiment shown in
It should be noted that the end result of raising motor 106 well above the water line could also be achieved, for example, by extending guy line 504 above the deck of bow 304 or by pivoting thruster unit 101 relative to car 501. In another embodiment, guy line 504 could be loosened from upper hull attachment 503 to allow thruster unit 101 to be lifted up onto the deck.
It should also be noted that upper hull attachment fixture could be mounted directly to bow 304 rather than bow sprit 505. This example shows it attached to bow sprit 505 to demonstrate that guy line 504 merely needs to be anchored in some way near the top of hull 304. Guy line 504 could, for example, be attached to bow 304 by running it through pulley block 305 and tying it to lashing point 306.
Guy line 504 is attached to hull attachment fixture 502 (not shown in this view). Hull attachment fixture 502 is mounted to hull 304 thus providing a secure attachment for guy line 504. Hull attachment fixture 502 includes a guide rail feature that engages with the channel in car 501 once car 501 has slid to the bottom of guy line 504. This guide rail feature prevents car 501 from rotating around guy line 504 and from torqueing guy line 504 when thruster unit 101 is thrusting. Thus, the combined mechanical constraints of guy line 504 and hull attachment fixture 502 fully constrain the movement of thruster unit 101 relative to bow 304.
In the embodiment shown in
It should be noted that the end result of raising motor 106 well above the water line could also be achieved, for example, by extending track 302 above the deck of bow 304.
Thruster unit 701 can be removed from the bow of the boat by continuing to raise it off the end of track 302.
In
The embodiments solves the problems of conventional bow and stern thrusters by eliminating the need for any electrical power or signal connections to the boat, and by providing for above-the-waterline external attachment of a fully integrated thruster unit. These features allow the thruster motor to be deployed below the waterline during use and subsequently retracted while under way. This ability to retract the thruster motor eliminates drag and prevents corrosion and seaweed from accumulating on the propellers or other propulsion mechanisms. The ability to mount the fully integrated thruster unit externally above the water line eliminates the need for the conventional thruster tunnel and subsequent hull modifications. It also eliminates the need for hauling the boat out of the water. Together, these features greatly reduce the cost of installation and ownership.
The thruster unit described here contains the batteries, the radio receiver, the control logic, the electrical power drivers and the thruster motor needed to make a stand-alone bow or stern thruster. The thruster unit rides up and down along a guide device that has one end mounted to the hull of the boat near the water line and the other end mounted to the boat up near the deck. By pulling on a tether line attached to the thruster unit the thruster unit can be hauled up along the guide device so that the thruster motor is out of the water. When the thruster is again needed, the thruster unit can be lowered along the guide device by letting out the tether line.
The operator commands the thruster to either thrust left, thrust right, or to be off by manipulating the buttons of a radio transmitter. The transmitter communicates the operator's commands to the radio receiver in the thruster unit.
The radio link provides the command and control channel so that no control wires through the hull are required. The integrated batteries provide the thruster motor electrical power requirements so that no power wires through the hull are required.
There are many variants for mounting the thruster unit to the outside of the hull. An addition advantage is that all of the thruster functions are integrated into a single thruster unit freeing up the unit to be mounted exterior to the boat in a manner that provides for secure attachment while deployed and for removal from the water when not deployed.
It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. It should be noted that embodiments discussed in different portions of the description or referred to in different drawings can be combined to form additional embodiments of the present application. The scope should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
This patent application claims priority of U.S. Provisional Application No. 62/248,876 that was filed on Oct. 30, 2015. The entire content of the application referenced above is hereby incorporated by reference herein.
Number | Date | Country | |
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62248876 | Oct 2015 | US |