Abstract:
The floating drive-on docking system for a watercraft uses a main floatation portion where the watercraft rests when loaded and a pivoting entry portion for creating a low loading angle between the watercraft and the floating drive-on docking system, resulting in only a small amount of propulsion from the watercraft being required to load onto the docking system. The pivoting entry portion has entry features, either rollers or raised bumps, that remain above the waterline when not engaged by the watercraft to keep the loading surfaces free from marine growth that can harm the hull of a watercraft. Wide side guides on the pivoting entry portion assist in positioning the craft for loading onto the docking system.

Description:
BACKGROUND OF INVENTION 
     This invention generally relates to a floating drive on docking system for a watercraft and more particularly to a drive-on docking system for a personal watercraft (PWC) with a pivoting entry to allow for easy loading and unloading. 
     The use of floating drive-on watercraft lifting devices is well known. A number of floating lift designs are currently known that provide this basic function. Most floating drive-on watercraft lifts are made from rotationally molded plastic and are either filled with air or foam for floatation. These lifting devices commonly have a ramped portion for loading and unloading the watercraft, a cradled docked portion for storing the watercraft and some sort of roller system or raised plastic ridges to help in transporting the watercraft from the ramped portion to the cradled portion and visa versa. A common trait among the current floating drive on watercraft lifting devices is a high loading angle between the watercraft and the lifting device. The abrupt ramped portion of the docking device forces the bow of the entering watercraft up creating the large loading angle between the watercraft and the floating lift requiring a large amount of propulsion from the watercraft to load. For an unskilled watercraft user loading can be very difficult and possibly dangerous. With too much propulsion the watercraft can easily slide over the lift and crash into any items in front of the drive-on lift. Examples of this type of floating drive-on watercraft lifting device are the Hydrohoist Hydroport (U.S. Pat. No. 7,293,522 to Elson), U.S. Pat. No. 6,431,106 to Eva, III et al., and the Jet T by Carolina Water Works, Inc. 
     Several devices use keel entry rollers to ease in loading the watercraft onto the dock including U.S. Pat. No. 6,006,687 to Hillman, U.S. Pat. No. 7,069,872 to Ostreng et al., and the EZPort from EZ Dock. The keel rollers help with reducing the propulsion required for loading, but marine growth can be a problem with keel rollers. If the keel roller sits in the water, marine growth, such as barnacles, muscles, oysters, etc., builds up on the roller and can damage the hull of a watercraft. Some companies choose to position the keel roller above the waterline to prevent marine growth, but this causes more problematic loading issues. With the keel roller above the waterline, the bow eye of a watercraft can catch on the keel roller while loading causing a significant jolt to the driver of the watercraft, and the loading angle is increased requiring more propulsion to load the watercraft leading to the same loading issues as the Hydrohoist Hydroport and like lifting devices. 
     The Tilting Dry Dock of U.S. Pat. No. 5,855,180 to Masters tries to address the loading issues of the above devices with a floating dock that seesaws to change the loading angle and reduce the propulsion required to load a watercraft. While the seesaw concept allows for reduced propulsion to load the watercraft, it does not address the growth issues that can damage the hull of a watercraft. Without a watercraft on the seesaw dry dock, the entry of the dry dock sits in the water where growth can build up. Furthermore, with the seesaw design a watercraft can be errantly launched if a person or animal walked to the back of the seesaw. 
     Another common problem among the current state of the art floating drive-on watercraft lifts is that most of them have a square or flat entry which requires the watercraft to be aligned properly with the entry for the watercraft to be properly loaded. If the watercraft is loaded at an angle the watercraft will slide off the side of the lift and back into the water, again, causing loading problems for the unskilled watercraft user as most PWCs do not steer very well at low speed. 
     Accordingly, the present invention is designed to allow for safe and effortless loading and launching of the watercraft on a floating drive-on watercraft lift. 
     SUMMARY OF THE INVENTION 
     The disclosed embodiments of the present invention are floating drive-on docking systems for a watercraft that allows for safe and effortless loading and launching of the watercraft, despite the skill level of the watercraft user. The floating drive-on docking system uses a main floatation portion where the watercraft rests when loaded and a pivoting entry portion for creating a low loading angle between the watercraft and the floating drive-on docking system, resulting in only a small amount of propulsion from the watercraft needed to load onto the docking system. 
     The pivoting entry portion has entry features, either rollers or raised bumps, that remain above the waterline when not engaged by the watercraft thereby keeping the loading surfaces free from marine growth that can harm the hull of a watercraft being loaded. When a watercraft engages the entry features of the pivoting entry portion, the pivoting entry portion pivots downward. The entry features further engage the watercraft hull below the waterline. The pivoting entry portion pivots downward until a downward stopping device of the pivoting entry portion engages the main floatation portion of the docking system, thus creating the desirable low loading angle between the watercraft and the docking system. In the disclosed embodiments the pivoting entry portion is buoyant to keep the entry features above the waterline when not engaged by the watercraft. 
     Once the watercraft is gently propelled through the pivoting entry portion, rollers guide the watercraft to the loaded position on the main floatation portion. The bow of the watercraft comes to rest on a bow stop. The portion of the bow stop that comes in contact with the bow of the watercraft is replaceable because of normal wear and tear. Once the watercraft is in the loaded position the pivoting entry portion pivots upwards and the entry feature return above the waterline. In addition to creating ease of watercraft loading, the pivoting entry portion provides extra buoyancy to the stern of the docking system when an upward stopping device of the pivoting entry portion engages the main floatation portion of the docking system. 
     The pivoting entry portion is shaped somewhat like a “U” to serve as a watercraft loading guide. The “U” shape is wider than half the maximum chine beam of a watercraft suitable for the docking system. The “U” shaped guide aids in loading the watercraft onto the docking system at loading directions between 0° and 90° (0° being aligned with the docking system) whereas the prior art described above requires watercraft to be substantially aligned between 0° and 10° with the docking systems to be loaded properly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of a floating drive-on watercraft lift. 
         FIG. 2  is a top plan view of the floating drive-on the watercraft lift of  FIG. 1 . 
         FIG. 3  is a cross-sectional side view of the floating drive-on watercraft lift of  FIG. 1  with the pivoting entry portion above the waterline in a stored position. 
         FIG. 3   a  is a cross-sectional side view of the floating drive-on watercraft lift of  FIG. 1  with the pivoting entry portion above the waterline in a resting position. 
         FIG. 4  is a cross-sectional side view of the floating drive-on watercraft lift of  FIG. 1  with the pivoting entry portion below the waterline. 
         FIG. 5  is side view of the floating drive-on watercraft lift of  FIG. 1  loaded with a watercraft in the loaded position. 
         FIG. 6  is a side view of the floating drive-on watercraft lift of  FIG. 1  with a watercraft loading. 
         FIG. 7  is a second embodiment of the floating drive-on watercraft lift. 
         FIG. 8  is an isometric detail view of the pivoting entry portion of the floating drive on watercraft lift of  FIG. 7 . 
         FIG. 9  is a side view of the floating drive-on watercraft lift of  FIG. 7  with the pivoting entry portion above the waterline. 
         FIG. 10  is a side view of the floating drive-on watercraft lift of  FIG. 7  with a watercraft loading. 
         FIG. 11  is side view of the floating drive-on watercraft lift of  FIG. 7  loaded with a watercraft in the loaded position. 
         FIG. 12  is a cross-sectional end view of the pivoting entry portion engaging on the main floatation portion of the floating drive-on watercraft lift of  FIG. 7 . 
         FIG. 13  is a top plan view of a watercraft loading the floating drive-on watercraft lift of  FIG. 7  at an angle. 
         FIG. 14  is a top plan view of a watercraft loading the floating drive-on watercraft lift of  FIG. 7 . 
         FIG. 15  is an enlarged plan view of a hull roller used with the floating drive-on watercraft lift of  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION 
     This following descriptions illustrate aspects of the invention, and identify preferred embodiments of these aspects. The descriptions are not intended to be exhaustive, but rather to inform and teach the person of skill in the art who will come to appreciate more fully other aspects, equivalents, and possibilities presented by invention, and hence the scope of the invention is set forth in the claims, which alone limit its scope. 
     Several details of the preferred embodiments are set forth in the following description:  FIGS. 1 through 14  provide a thorough understanding of such embodiments. One skilled in the art will understand that the present invention may be practiced without several of the details described herein. In the following description of the embodiments, it is understood that a watercraft includes any vehicle that is at least partially waterborne, which includes boats and similar vessels, but may also include amphibious vehicles including various amphibious automobiles or aircraft. Moreover, in the description that follows, it is understood that the figures related to the disclosed embodiments are not to be interpreted as conveying any specific or relative physical dimension, and that specific or relative dimensions related to the embodiments, if stated, are not be considered limiting unless the claims state otherwise. 
       FIG. 1  is an isometric view of a drive-on watercraft lift  10  for receiving a watercraft  51  (see  FIGS. 5 and 6 ) driven onto the lift under its own propulsion. The drive-on watercraft lift  10  includes a floating structure  11  having an aft port extension  21 , an aft starboard extension  22 , and an aft opening  23  therebetween. The floating structure  11  further includes a front  24  having a bow stop  14 , a rear pivoting entry portion  30 , a keel roller  12  located forward of the pivoting entry portion, and hull rollers  13  located along a mid-portion of the floating structure between the bow stop and the keel roller. The bow stop  14  is configured to contact the watercraft  51  (see  FIG. 5 ) at a location above the waterline for engaging and limiting forward movement of the watercraft loaded onto the drive-on watercraft lift  10 . 
       FIG. 2  is a top plan view of the drive-on watercraft lift  10  showing aft port extension  21 , aft starboard extension  22 , aft opening  23 , and front  24 . The combined volume of aft port extension  21  and aft starboard extension  22  is substantially less than the volume of front  24  because of the presence of aft opening  23 . The purpose of aft port extension  21 , aft starboard extension  22 , and aft opening  23  will be described below with respect to  FIG. 6 . 
       FIG. 3  is a cross-sectional side view of drive-on watercraft lift  10  showing more detail on pivoting entry portion  30 . Pivoting entry portion  30  comprise a roller assembly having a keel roller  33  attached to and positioned between rearward end portions of left and right side pivot extensions  31 . The pivot extensions  31  are each pivotally mounted on a pivot  32 , with the left side pivot extension being pivotally attached to the aft port extension  21  and the right side pivot extension being pivotally attached to the aft starboard extension  22 . A counterbalance  34  is attached to and positioned between a forward end of left and right side pivot extensions  31 . When keel roller  33  is not in contact with the hull of a watercraft (not shown), counterbalance  34  keeps pivoting entry portion  30  in the illustrated stored position “A” shown in  FIG. 3  with keel roller  33  above the waterline and free from marine growth while left and right side pivot stops  36  keeps pivot extensions  31  in a substantially horizontal position. 
       FIG. 3   a  is a cross-sectional side view of the drive-on watercraft lift  10  showing pivoting entry portion  30  in the illustrated resting position “AA” with keel roller  33  substantially out of the water to prevent marine growth on keel roller  33 . 
       FIG. 4  is a cross-sectional side view of drive-on watercraft lift  10  with pivoting entry portion  30  in the illustrated load position “B”. As the bow of a watercraft (not shown) approaches the drive-on watercraft lift  10  the bow will contact keel roller  33  causing pivot extension  31  of pivoting entry portion  30  to rotate downward on pivots  32 . This causes the forward end portions of left and right side pivot extensions  31  to rotate upward until they contact left and right side pivot stops  35 , thereby allowing keel roller  33  to support the load of the loading watercraft. With this arrangement, the watercraft will continues to move up and onto the drive-on watercraft lift  10  in a smooth and safe manner. 
       FIG. 5  is a side view of drive-on watercraft lift  10  in the illustrated loaded or neutral floating position “C” where the top surface of drive-on watercraft lift  10  is parallel to the waterline when a watercraft  51  is on the drive-on watercraft lift. 
       FIG. 6  is a side view of drive-on watercraft lift  10  in the loading position “D” where the top surface of the drive-on watercraft lift  10  is angled back compared to the waterline. As watercraft  51  contacts aft port extension  21  and aft starboard extension  22  as it passes over and at least partially enters aft opening  23 , the aft portion of drive-on watercraft lift  10  is pushed under the waterline due to the volume differential between the front  24  and aft port extension  21  and aft starboard extension  22 . As the watercraft  51  further loads onto drive-on watercraft lift  10 , the drive-on watercraft lift approaches the illustrated loaded position “C” shown in  FIG. 5  in a smooth and safe manner. 
       FIG. 7  is an isometric view of a second embodiment drive-on watercraft lift  70  comprising of a rear pivoting entry portion  71  pivotally attached to a one-piece main flotation portion  72  by pivots  75  at a forward end of the pivoting entry portion arrange along a laterally extending, substantially horizontal hinge line. The pivoting entry portion  71  includes starboard and port entry features  73  which engage the hull of the watercraft when loading and unloading and are shown as rollers in  FIG. 7  and raised bumps in  FIG. 8 , a watercraft guide entryway cutout or opening  74 , hull rollers  77  located just forward of the watercraft guide entryway opening, and the pivots  75  located forward of the hull rollers  77 . The main floatation portion  72  includes two sets of hull rollers  76  and a bow stop  78 . The bow stop  78  is configured to contact the watercraft  51  (see  FIG. 11 ) at a location above the waterline for engaging and limiting forward movement of the watercraft loaded onto the drive-on watercraft lift  70 . Bow stop  78  has through-hole  79  for running a lanyard to the bow eye of a watercraft (not shown). Bow stop  78  is preferably higher than the draft of the watercraft, and the portion of the bow stop positioned to touch the watercraft is removable and separately replaceable from main floatation portion  72 . 
     The watercraft guide entryway opening  74  is defined at the forward end thereof by a transverse member at which the hull rollers  77  are located, and by starboard and port rearward extensions of the pivoting entry portion  71  extending rearward from the transverse member, with the starboard and port entry features  73  being located toward the rearward end of the starboard and port rearward extensions. The watercraft guide entryway opening  74  is rearwardly opening to provide access by the watercraft  51  between the starboard and port rearward extensions, and the width of the watercraft guide entryway opening between the starboard and port rearward extensions is preferably wider than half the max chine beam of the watercraft  51 . As will be described below, the watercraft guide entryway opening  74  of pivoting entry feature  71  centers the watercraft  51  on drive-on watercraft lift  70  for ease of entry, and assists in longitudinal axial alignment of the watercraft with the watercraft lift. 
     The rollers used for the starboard and port entry features  73  and the hull rollers  77  of the pivoting entry portion  71 , and the hull rollers  76  of the main floatation portion  72 , shown in  FIG. 7  have the same general construction, and one of the hull rollers  76  which is representative of all these rollers is shown in  FIG. 15 . The hull roller  76  has a generally cylindrical contact portion  157  and reduced diameter generally cylindrical portions  151  and  152 , one to each side of the contact portion  157 . Contact portion  157  of the hull roller  76  has a diameter sufficient to contact and support the watercraft  51  and a width of less than 3 inches. The reduced diameter portions  151  and  152  each have a diameter sufficiently less than the diameter of the contact portion to avoid contact with a hull strake of the watercraft when loading and unloading the watercraft. The overall length  154  (shown as 7 inches) of each hull roller  76  is more than twice the width of the roller&#39;s contact portion  157 . The contact portion  157  of the hull roller  76  is preferably located off the center of the roller, and in the illustrated embodiment of  FIG. 15 , a transverse center line  153  of the contact portion  157  is located at a distance  156  (shown as 3.65 inches) from the outward end of the reduced diameter portion  151 , and at a distance  155  (shown as 3.35 inches) from the outward end of the reduced diameter portion  152 . 
       FIG. 8  is an enlarged isometric view of pivoting entry portion  71  shown separate from the main flotation portion  72  showing up stop  81  and down stop  82  on the starboard side of the pivoting entry portion. The same up stop  81  and down stop  82  are located on the port side of the pivoting entry portion  71 . Entry portion  71  is positively buoyant and is filled with foam or air. As noted above, in  FIG. 8  the entry features  73  of pivoting entry portion  71  are shown as raised bumps rather than the rollers shown in  FIG. 7 . 
       FIG. 9  is a side view of unloaded floating watercraft lift  70  with pivoting entry portion  71  in illustrated position “A” with entry features  73  above waterline and free from marine growth. The floatation of pivoting entry portion  71  keeps entry features  73  above the waterline. 
       FIG. 10  is a side view of the floating watercraft lift  70  with a watercraft  51  in the process of loading. When watercraft  51  comes in contact with pivoting entry portion  71 , the pivoting entry portion pivots downward causing entry features  73  to drop below the waterline to illustrated position “B” and engage watercraft  51 . As best illustrated in  FIG. 12 , down stop  82  engages main floatation portion  72 . The combination of the entry features  73  dropping below the waterline to engage the watercraft  51  and the down stop  82  engaging the main floatation portion  72  creates a low loading angle between the watercraft and the watercraft lift  70  allowing for watercraft loading with minimal propulsion required from the watercraft. 
       FIG. 11  is a side view of the floating watercraft lift  70  with watercraft  51  loaded. Pivoting entry portion  71  returns to illustrated position “A” with entry features  73  above the waterline and free from marine growth. The floatation of pivoting entry portion  71  keeps entry features  73  above the waterline. If watercraft  51  is heavy, up stop  81  of pivoting entry feature  71  may engage main floatation portion  72 , thereby effectively providing more buoyancy to the stern of watercraft lift  70 . 
       FIG. 12  is a cross-sectional end view of watercraft lift  70  showing down stop  82  of pivoting entry portion  71  engaging on main floatation portion  72 . 
       FIG. 13  is a top plan view showing watercraft  51  loading drive on watercraft lift  70  at a loading direction between 0° and 90°. Watercraft guide entryway opening  74  of pivoting entry feature  71  centers the watercraft  51  on drive-on watercraft lift  70  for ease of entry. By the watercraft guide entryway opening  74  assisting in longitudinal axial alignment of the watercraft  51  with the drive-on watercraft lift  70 , the loading direction of 0° shown in  FIG. 14  can more easily be achieved. 
       FIG. 14  is a top plan view showing watercraft  51  aligned at a loading direction of 0° with drive-on watercraft lift  70 . 
     In a preferred embodiment, the drive-on watercraft lift has the pivoting entry portion pivotally attached to the main flotation portion along a substantially horizontal hinge line. Further, the drive-on watercraft lift contains at least two sets of roller. Preferably, the rollers are sufficiently wide to distribute load to the main floatation portion, but have a narrow contact portion to avoid the strakes of the watercraft. The narrow contact portion of the roller is preferably off-center.