Patent Application
20170274967
This is a continuation in part of U.S. patent application Ser. No. 14/444,935 filed Jul. 28, 2014 by applicants which was a US non-provisional patent application related to US Provisional Patent Application No. 61/859,188 filed Jul. 27, 2013 by applicants, which claimed the benefit of the provisional filing date.
Field of Invention
The current invention relates to an apparatus and method for modifying the wake of a ski boat. More particularly, a device is temporarily attached to one side of the stern of a boat in order to modify the wake pattern of the boat.
Prior Art
When the boat hull length is an exact mirror image from side to side, then the boat's wave rolls from each side of the boat and meets in the center.
In the current invention, a wake shaping device is attached on one side of the stern, thereby effectively making one side of the boat longer than the other side. This modification delays the formation of the wave on the opposite side so that it is behind the natural wave formation on the side where the wake shaping device is installed. This modification lifts the water and causes the wake to be taller and longer on the opposite side from the installation of the wake shaping device. The delayed wave on the opposite side of the boat from the wake shaping device allows the wave to crest over the natural wave on the side where the device is installed.
The sport of wake surfing is currently the fastest growing segment of behind-the-boat water sports. Wake surfing involves a short surfboard and a short rope that is only used to get up from the water, then is thrown into the boat as the rider gets comfortable on the wave. When the rope is thrown in the boat, the wake surfer rides the boat wake as he or she would an ocean wave. To get a wake large enough to ride, people add ballast bags to the back of the boat, oftentimes on the side where the wake surfer is riding, tilting the boat to one side. It is also common practice to put all of the people in the boat on the side the wake surfer is riding to further weight that side. This tilting of the boat can cause the boat to take on water when going over larger waves and can also cause difficulty for the driver, as weight in the stern of the boat makes the bow of the boat ride higher causing obstructed sight lines.
The wake shaping device of the current invention makes ballast and other weighting of the boat less necessary, as the extension of the boat increases wake height and performance without adding weight to the boat. If ballast is used, then the boat can be weighted evenly, and spectators in the boat can distribute their weight more evenly. This affords the driver clearer sight lines for safer driving. It also allows the boat to ride higher in the water, as it was designed, so the boat doesn't take on water when going over larger waves. For more advanced riders, ballast may be required.
Wake surfing is performed close to the stern of the boat, as that is where the boat wake crests and forms the best surfing wake. This can be dangerous for beginner surfers, if they are not accustomed to shifting their weight from front to back on the surfboard to control their momentum and placement on the wake. Surfing so close to the stern of the boat can also be dangerous, as the wake surfer is close to where the exhaust exits the back of the boat. Exhaust fumes can have obvious negative affects on the wake surfer, including carbon monoxide poisoning.
The wake shaping device of the current invention elongates the “sweet spot” of the wake, the area where the rope goes slack and the wake surfer can ride without the rope, allowing them to ride further back from the stern of the boat in a safer zone. It also makes the wake taller and firmer, minimizing the froth of the wave. Froth does not have any forward push to give the surfer the momentum needed to stay with the boat.
Ballast tanks are filled and drained according to which side the wake surfer surfs on, so there is some down time between surfers if they ride on different sides. The wake shaping device allows for a quicker shift from side to side, as ballast tanks do not need to be emptied and refilled between surfers.
In one embodiment of the current invention, there are separate, specifically molded wake shaping devices for port- and starboard-side surfers.
In another embodiment, a single wake shaping device may be temporarily installed on either side of the boat by inverting the device when installed on the opposite side.
Some makes and models of boats have built in wake surfing devices. Malibu offers Surf Gate™, which is a complicated mechanical system tied to electronics and electric actuators. Electric motors drive a hinged flat board from the back of the platform toward the outside of the boat. It is electronically controlled from the driver's console. It cannot be retrofitted on other models of boats and costs thousands of dollars as an upgrade package. Nautique's version is also not retrofittable and costs thousands of dollars for the upgrade package. Nautique has a plate that is mounted flat to the stern of the boat. Electric motors drive the plate out and down, beyond the edge of the boat, changing the wake shape. To get boats with these options, the base boat is nearing $100,000.
The wake shaping device of the current invention is much less expensive than the upgrade packages of other manufacturers.
In one embodiment, the device may It will be molded specifically to the design of the different boat manufacturers' sterns, ensuring optimal fit. The devices are retrofittable and can be molded to fit nearly any existing inboard boat's stern.
In another embodiment, the device may be provided with a custom insert that is configured to fit a particular boat model stern profile and platform.
In one embodiment, the wake shaping device uses a vacuum cup attachment means. Some manufacturers sterns will require more than one vacuum cup.
In one example, the wedge shape of the wake shaping device utilizes water pressure to distribute the load evenly across the fastening side of the device, thereby allowing for a tight fit to the back of the boat.
There are not any electronic systems to install or repair. The compact size and light-weight design of the wake shaping device will not clutter or weight down the boat. When the device is not in use, it is stored inside the boat.
In one embodiment of the current invention, a wake shaping device is fastened to one side of the back of an inboard boat. In one example, the wake shaping device comprises a molded scoop-shaped extension, one or more vacuum cups, and safety connection.
In another example, the device is attached to a mechanical mounting bracket on the boat stern.
In another example, the device is supported by a providing a notch in the mounting face of the device, and resting the device notch on a portion of the boat platform. While the boat is moving forward, water forces the device against the stern, so very little mechanical support is required to hold the device in place. A strap or cord is typically provided to tie the device to the boat if it becomes dislodged, but simply slipping part of the device over a portion of the boat platform has worked well in testing with several boat models.
The side and bottom of the wake shaping device work together to displace the water and shape the wake. Reinforcement features may me provided to strengthen the top or bottom surfaces.
Varying degrees of a twist or flare can be molded into the wake shaping device to additionally enhance the wake.
A vacuum cup may be recessed into the wake shaping device so that the mounting surface attaches to the stern is as close as possible to the boat. Testing has demonstrated that a gap between the stern and the mounting face is not detrimental.
A lanyard may be used as a safety in the rare event that suction is lost in the vacuum cup.
A vacuum cup pressure relief valve may be extended to above waterline and may be attached to the boat eyelet along with the lanyard. Having the vacuum cup pressure relief valve above waterline allows for easier securing and release from the boat, because air is transferred through the vacuum cup much easier than water. The vacuum cup may have a pump device that is pumped to secure it to the back of the boat.
The wake shaping device can be shaped and notched to fit around swim platforms or other features installed by boat manufacturers.
Starboard Wave Shaping Device
In this embodiment, the wave shaping device 101 comprises a frame with a side surface 110 which is angled outwardly approximately 12 degrees from the starboard side 81 of the boat 80. The device also comprises a front mounting surface 150 (not shown) which is preferably shaped to match the mounting area of the stern 90; a top surface 120; rear surface 130; and a bottom surface 140 (not shown).
Port Wave Shaping Device
Wave Shaping Device with Side Surface and a Mounting Surface Only
Wave Shaping Device with Side Surface Extending Below Hull
Variations
Applicant has found that a relatively small frame with a side extension on one side of the boat provides unexpectedly large benefits in wave height, wave firmness, and forming the wave board wave portion further from the boat. Applicant's invention is not limited to the specific examples described, but includes variations described below and other variations that may be apparent to those skilled in the art.
Platform Index Notch Mounting
In this example, front mounting surface details for the platform index notch 480 and the reinforcement ridge 422 are configured to match the boat stern and platform. In other examples, the boat-specific stern and platform mating geometries may be provided on an insert plate, so that a wave shaping device 401 front mounting surface 450 may accept various boat model-specific insert plates.
Dual Part and Stern Device
In the previous examples, separate stern and starboard devices are provided. In other embodiments, a single device may be used on either the stern and starboard side.
The dual mounting approaches have not been tested, but are expected to work based on the observed insensitivity of the device to top, bottom, and rear surface profiles.
Materials
The example devices were constructed of vacuum-formed coextrusion of acrylic and ABS. Other materials including polyethylene, polypropylene, other thermoplastics fiberglass, urethane foams, and metal may be used.
Vacuum Cup(s)
The test boat for the example devices described above had relatively large flat mounting areas on the stern, so a single 8 inch vacuum cup could be used. The 8-inch vacuum cup secured the wave shaping device when the boat was driven at a speed in excess of 25 mph—which is much greater than typical speeds of 7 to 12 mph for wake surfing.
The vacuum cup was a model which is used for moving glass and granite slabs. Other vacuum cups that we have used are made by SeaSuckerT™ and include a 4.5″ model and a 6″ model.
In other cases, two or more vacuum cups can be provided to provide an adequate mounting area on a more complex stern shape.
Some vacuum cups require the user to break the suction by squeezing a tab and relieving the vacuum pressure underneath the cup.
Other Mounting Methods
In these examples, the wave shaping device was temporarily attached to the boat with vacuum cups. Other mounting methods may be used including various mounting brackets and clamps.
Side Angle
In various experiments, side outward angles of up to 20 degrees were evaluated. A side angle of about 12 degrees provided the best results for the particular ski boat used. Other boats may have different optimum angles.
Side Flare
The examples described above have relatively flat side portions. Applicant had expected improved wave shape if the side portions were flared outwardly. However, limited testing has not established that benefit for the test boat used.
Gasket
The device was tested with and without a gasket. With the recessed vacuum cup, the gasket did not make a significant improvement on the test boat. Applicant theorizes that the force of the water on the outwardly projecting side surface acts to compress the vacuum cup against the stern and to resist shear forces that would detach the device.
Mounting Shape
The example devices were designed for a particular boat model, including cutouts for a swimming platform and a lip extension. Other boat models might have different mounting surface profiles.
The scope of the invention is not limited to the particular examples and embodiments described above.
