Abstract:
Embodiments of the present invention include a stationary boat lift in which boats can enter and exit quite readily. The boat lift allows a boat to bypass various barriers in a safe and efficient manner by orienting the boat in a direction substantially parallel to the barrier, vertically lifting the boat out of one waterway, laterally translating the boat horizontally over the barrier, and then vertically lowering the boat into a second waterway.

Description:
[0001]     This utility patent application claims priority to U.S. Provisional patent application Ser. No. 60/725,535 filed on Oct. 11, 2005, which is incorporated herein by reference in its entirety. This application also incorporates by reference U.S. Pat. Nos. 6,457,904; 6,174,106; and 5,947,639. 
     
    
     TECHNICAL FIELD  
       [0002]     The embodiments of the present invention relate to a lifting apparatus used to portage a boat. More specifically, the embodiments of the present invention relate to mechanisms and methods for lifting a boat out of a body of water and transferring the boat horizontally over a barrier.  
       BACKGROUND  
       [0003]     In the context of this invention, “portage” means to carry a boat and/or its supplies overland from a first body of water, between two waterways or around an obstacle to navigation. Known within the prior art are devices for lifting boats out of water for such purposes as making repairs, protecting them from dock collision caused by tidal action, and mitigating or preventing damage to their hulls due to excessive water exposure. U.S. Pat. No. 5,184,914 describes and shows a boat lift that consists of a frame that cradles and lifts a boat from the water by means of a hydraulic ram. The device requires a person to enter the water to secure several members of the device around the bottom of the hull. U.S. Pat. No. 5,593,247 describes a programmable boat lift control system that with the push of a button causes the lift to either raise or lower the boat to a pre-programmed elevation.  
         [0004]     Both of these devices are useful for their intended purposes, however, both are limited to lifting and lowering the boat in a vertical direction. Unfortunately, this was indicative of the general state of the art in boat lifting devices. The prior art fails to teach an apparatus that can lift and lower a boat in a vertical direction, as well as transfer the boat in a horizontal direction. Prior art references also fail to teach orienting a boat parallel to the barrier and then lifting the boat out of the water. By orienting a boat parallel to the barrier it is meant that the starboard or port side of the boat is juxtaposed to the edge of the barrier. Applicant has discovered the need to transfer boats over barriers, from one body of water to another. Notably, in many areas, salt water and fresh water are separated by various types of barriers, such as water divider walls and land barriers. Often barriers are needed to separate fresh from salt water due to the various types of organisms, plants, and animals that can survive only in one type of environment, i.e., either in salt or in fresh water, but not both. Regardless of the need to isolate salt from fresh water, boats and other water vehicles frequently require access to, from, and between separate water bodies.  
         [0005]     A novel approach to prior art inventions includes a lifting apparatus that allows an operator to orient their boat sideways in relation to the lifting apparatus and/or barrier (i.e., perpendicular to the line of travel). In this fashion, the boat will be easier to maneuver and control. Also, for many boats, the hull shape would suggest that its center of gravity will be positioned more appropriately. Therefore, there is a need to provide a lift that allows a boat to be oriented in a sideways manner relative to the barrier and to portage the boat in that direction (i.e., star-board-to-port or vice versa).  
       SUMMARY  
       [0006]     In one embodiment of the present invention a boat lift includes a base structure having a first frame section erected over a barrier wherein the barrier is juxtaposed to at least a first body of water. It is noted that the barrier may also separate two bodies of water or an obstacle to navigation in the water. The base structure may also include a second frame section cantilevered over the first body of water, and a lift frame operatively connected to the base structure. A cradle assembly, including a cradle support and/or boat sling capable of receiving an associated boat for carrying the associated boat across the barrier, is moveably connected to the lift frame and more specifically to the base structure. A mechanism or actuator for actuating the cradle assembly is also incorporated into the boat lift.  
         [0007]     One aspect of the embodiments of the present invention includes a horizontally moveable lift frame capable of traversing the second frame section, and a mechanism for actuating the lift frame.  
         [0008]     Another aspect of the embodiments of the present invention includes the base structure having a third frame section cantilevered over a second body of water where the horizontally moveable lift frame is capable of traversing the third frame section.  
         [0009]     In yet another aspect of the embodiments of the present invention the lift frame and the cradle assembly are capable of translating the associated boat across the barrier with either of the associated boat&#39;s port side or starboard side approaching the barrier. The horizontally moveable lift frame and the cradle assembly are capable of carrying and releasing the associated boat into the second body of water in a direction substantially parallel to the barrier.  
         [0010]     Still another aspect of the embodiments of the present invention includes a boat lift apparatus having a non-water retaining boat-support mechanism that includes one or more flexible straps for receiving the associated boat, wherein the one or more flexible straps are selectively adjustable to receive one of first and second substantially different associated boats. The non-water retaining boat-support mechanism may also include a net for receiving and lifting the associated boat.  
         [0011]     In another embodiment of the present invention a method for transporting a boat over a barrier juxtaposed to a first body of water includes the steps of providing a base structure having a moveable lift frame and a cradle assembly, positioning the moveable lift frame extending over the first body of water, positioning the cradle assembly into the first body of water, maneuvering an associated boat into the cradle assembly, wherein the starboard or port side of the associated boat is juxtaposed to the barrier, raising the cradle assembly to lift the associated boat out of the first body of water and to an elevation that is higher than the barrier, and translating the associated boat across the barrier.  
         [0012]     After the boat has entered the boat lift it may be positioned over a boat-support mechanism. This means of support could be adjustable, such as a set of two or more nylon straps. However, it is contemplated that alternate supporting mechanisms could be used including a heavy gauge net and/or a rigid cradle assembly. In employing straps, one strap may be located near the bow or front portion of the boat while another strap may be located near the stern or rear portion of the boat. A motor and cables may be used to lower or raise the cradle.  
         [0013]     Once the boat is in a fully raised position, the boat lift translates the boat in a substantially horizontal direction over the barrier. Translating is actuated by a motor which powers a conveyance mechanism, such as a set of track wheels, to move the boat lift back and forth. An operator is able to easily control the functioning of the boat lift through a control panel located near or within the boat lift. It is also contemplated that an operator may direct the boat lift&#39;s functioning via a remote control device. In one embodiment, the boat lift may serve as an alternate to a lock, whereby the bodies of water may be at different levels. Despite the differences in relative elevations, the boat&#39;s movement may still be in a substantially horizontal, albeit inclined, direction of travel.  
         [0014]     One aspect of the embodiments of the present invention includes laterally translating the associated boat with respect to the associated boat&#39;s forward direction of travel.  
         [0015]     Another aspect of the embodiments of the present invention includes positioning the moveable lift frame and the boat over a second body of water and lowering the cradle assembly to release the boat into the second body of water where the starboard or port side of the associated boat is juxtaposed to the barrier.  
         [0016]     Yet another aspect of the embodiments of the present invention includes a vertically moveable cradle assembly where the cradle assembly includes a boat cradle and/or boat sling capable of receiving a boat, for carrying the boat across the barrier and for releasing the boat into the second body of water in a direction substantially parallel to the barrier.  
         [0017]     Another aspect of the embodiments of the present includes vertically moving the moveable cradle assembly to maintain a constant elevation above the surface of the barrier.  
         [0018]     Still another aspect of the embodiments of the present invention includes weights attached to a non-water retaining boat-support mechanism.  
         [0019]     Even another aspect of the embodiments of the present invention includes releasing the boat into the second body of water wherein the starboard or port side of the boat is juxtaposed to the barrier.  
         [0020]     Other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying figures. 
     
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0021]      FIG. 1  is a side elevation view of the boat lift apparatus in accordance with the embodiments of the present invention.  
         [0022]      FIG. 1   a  is a side elevation view of the boat lift apparatus showing two cantilevered ends in accordance with the embodiments of the present invention.  
         [0023]      FIG. 2  is an end elevation view of the boat lift apparatus in accordance with the embodiments of the present invention.  
         [0024]      FIG. 3  is a side elevation view of the boat lift apparatus without a roof structure in accordance with the embodiments of the present invention.  
         [0025]      FIG. 4  is a top view of the deck of the boat lift apparatus in accordance with the embodiments of the present invention.  
         [0026]      FIG. 5  is a bottom view of the lift frame of the boat lift apparatus in accordance with the embodiments of the present invention.  
         [0027]      FIG. 6  is an end view of the lift frame and the cradle assembly of the boat lift apparatus in accordance with the embodiments of the present invention.  
         [0028]      FIG. 7  is a front view of a boat lift apparatus in accordance with the embodiments of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0029]     In the following description of the embodiments of the present invention, reference is made to the accompanying drawings which, in conjunction with this detailed description, illustrate and describe a boat lift capable of hoisting a boat out of one body of water, translating the boat sideways in a horizontal direction over a barrier and then lowering the boat into a second body of water. Referring to  FIGS. 1 through 3 , boat lift  10  consists of a base structure  20 , lift frame  60 , and cradle assembly  100 . Base structure  20  may include a plurality of piering members or columns for supporting lift frame  60 , which may be horizontally moveable. The lift frame  60  may serve as a support structure for the cradle assembly  100 , which may be vertically moveable. Base structure  20  may be substantially rigid by, for example, anchoring the piering members or columns to the earth. The base structure  20  may further include a guiding mechanism such as tracks or rails, rollers, or bearings. The lift frame  60  may be moveably connected to the guiding mechanisms for translating the lift frame  60  back and forth in a generally horizontal fashion over the base structure  20 . In one embodiment, lift frame  60  rolls along tracks  34  of base structure  20 , which is erected over a barrier  18  separating a first body of water  14  and a second body of water  16 . “Bodies of water” may refer either to distinct bodies of water like, for example, the ocean and an inland waterway. “Bodies of water” may also refer to segments/region is within a common body of water. In  FIGS. 1 and 1   a,  boat  12  may be positioned next to either end of the boat lift  10  (i.e. from the first body of water  14  or from the second body of water  16 ). Accordingly, barrier  18 , which may be a man-made or a natural barrier, can be located between the first body of water  14  and the second body of water  16 . For example, many areas having both salt and fresh water bodies may need to prevent the two bodies of water from mixing, thereby contaminating the fresh water. Various types of organisms, plants, and animals can only survive in either salt or fresh water. Some barriers  18 , such as raised land barriers, may occur naturally. Alternatively, persons or communities may construct barriers  18  to separate two bodies of water, such as during the construction of a fresh water lake or canal. One aspect to the existence of barriers  18  is that boats are prevented from freely traveling between nearby, but navigably unconnected, bodies of water. As such, boat lift  10  may portage a boat  12  between bodies of fresh and salt water, and/or it may portage boats  12  between bodies of fresh water or between bodies of salt water.  
         [0030]     With continued reference to  FIGS. 1 through 3 , the base structure  20  may comprise concrete columns  22  driven into the earth, along with posts  24  to which are mounted top rail  26 , cross members  28 , track mounts  30 , track support member  32 , trade  34 , track stops  36 , and/or cantilevered-end supports  38 . Decking  40 , docks  42 , ladders  44 , and roof  46  may also be included with the boat lift  10 . The piering members or columns  22  may extend into the ground (or earth) at spaced intervals along the span of boat lift  10 . Accordingly, the columns  22  will need to access submerged ground. The number of columns  22  required depends on the span covered by the boat lift  10  and the associated strength requirements, which depends, at least in part, on the size of boats being portaged and the materials used to construct the boat lift  10  as would be evident to persons skilled in the art. Posts  24  affixed atop columns  22  may extend in a substantially vertical direction. Still, it is contemplated that posts  24  may extend in other directions, including a vertically inclined angle, which may be angled for the purpose of intersecting a neighboring post  24 . Generally, posts  24  provide for the attachment of a roof  46 . The base structure  20  may include top rails  26  and cross members  28 , which may be attached to posts  24 . Track  34  may comprise railroad track-like members, which attaches to track support member  32 . Track mounts  30  secure track support member  32  to column  22 . Stops  36  are mounted at the ends of track  34  to prevent lift frame  60  from over running track  34 . Stops  36  may comprise a plate or angle joined to track  34  and/or track support member  32 . In this manner, the base structure  20  may comprise a first frame section erected substantially over the barrier  18  and anchored to the columns  22 . When track  34 , and its associated components, extends from a column  22  without connecting to another column  22 , the track  34  becomes cantilevered. The portion of the base structure  20  that extends cantilevered over the first body of water may comprise a second frame section. Similarly, a third frame section may extend cantilevered over the second body of water, shown in  FIG. 1   a.  Cantilevering may be desirable for saving costs, or when the underlying earth is not suitable for accepting columns  22 , or when it is otherwise undesirable to utilize a concrete column  22 . The cantilevered frame sections may also facilitate maneuvering of or docking of the boat  12  next to the barrier  18  in a sideways fashion as will discussed in a subsequent paragraph. The posts  24 , top rail  26 , cross members  28 , track mounts  30 , track support member  32 , and cantilevered-end supports  38  may comprise wood beams, or metal (including steel or other alloys) or composite I-beams (i.e., S or W shapes), structural tees, angles, channels, tubing, or the like. The joining of all components may be achieved by any known means, such as welding, riveting, or bolting. To provide access to boat  12  when it is being portaged, base structure  20  may include a deck  40 , which may be attached to columns  22  at a location just above the water near the barrier  18 . Deck  40  may extend longitudinally between distal ends of boat lift  10 , and/or laterally between the sides of each end respectively. Ladders  44  may also extend from deck  40  to provide access to the water and/or a floating dock  42 , which may be anchored to base structure  20 . The base structure  20  may take on any variety of constructions that provide sufficient support for the cradle assembly  100 .  
         [0031]     With continued reference to  FIGS. 1 and 2 , the roof  46  may attach to base structure  20  adjacent posts  24  and/or cross-members  28 . The roof  46  may includes horizontal members  48 , center posts  50 , roof bows  52 , and roof coverings  54 . Horizontal members  48  attach to cross member  28  of base structure  20 . Center posts  50  extend vertically from the horizontal members  48  to join roof bows  52 . Roof bows  52  generally extend from the uppermost end of center posts  50  to attach to an end of horizontal member  48 , and may extend further if desired by the user. The quantity of horizontal members  48 , center posts  50 , and roof bows  52  may depend on the materials or beam design used for each, as well as the roof coverings  54  desired by the user. As a roof covering  54  becomes progressively heavier, the greater will be the need for either stronger materials or an alternate beam design including additional horizontal members  48 , center posts  50 , and roof bows  52 . Any known roof covering may be used, including shingles, metal roofing, or sheeting. The roof  46  may cover all or any portion of the boat lift  10 .  
         [0032]     With particular reference to  FIG. 5  but also to the remaining figures, the horizontally moveable lift frame  60  translates on track  34  and comprises structural and mechanical (translational and lifting) components. Lift frame  60  is shown generally as a rectangular structure formed by longitudinal side members  62  and lateral side members  64 . Internally, lift frame  60  may include a central drive unit guard  73 , which may be placed between lateral members  66  and an arrangement of longitudinal strengthening members  68 ,  69 ,  71 ,  72   a,    72   b . Larger strengthening members  68  may be located towards the center of lift frame  60  to compensate for the added weight associated with a lifting unit shown generally at  82 . Gussets  70  may extend from longitudinal side member  62  to lateral member  66 , in assisting to provide added strength and torsional rigidity and to reduce stress concentrations. The central drive unit guard  73  may also be formed from a rectangular frame  74  and a cover. Any or all structural members  62 ,  64 ,  66 ,  68 ,  69 ,  70 ,  71 ,  72   a,    72   b,  and  74  may comprise wood beams, or metal (such as steel) or composite I-beams (S or W shapes), structural tees, angles, channels, or tubing. The joining of all structural members may be achieved by known means, such as, but not limited to, welding, riveting, or bolting. It is noted here that the aforementioned configurations of the lift frame  60  and its components are exemplary in nature and are not to be construed as limiting. Rather, the moveable lift frame  60  may take on any variety of constructions sufficient for accomplishing lifting and portaging, as further described herein.  
         [0033]     With continued reference now to  FIG. 5 , as mentioned above, the lift frame  60  may include translating means, which in one embodiment may include track wheels  75 , wheel sprocket  76 , shaft, motor  77 , gear reducer  78 , drive sprocket  79 , and linkage  80 . Track wheels  75  may be flanged to operate on track  34 . However, this feature may depend on the type of track  34  used. The motor  77 , gear reducer  78  and drive sprocket  79  may mount externally at a corner of lift frame  60  along lateral side member  64 , while the corresponding track wheel  75 , wheel sprocket  76 , and shaft may mount externally at the same corner but along longitudinal side member  62  so that the linkage  80  may be mounted upon wheel sprocket  76  and drive sprocket  79  respectively. In one embodiment, two sets of track wheels  75  exist located externally at the corners of a common lateral side member  64 . Similarly, the two remaining external corners of lift frame  60  each include a track wheel  75 . The aforementioned constructions describe one embodiment for the lifting and portaging of a boat  12  in an essentially horizontal manner across a defined pathway. However, other translating means are also contemplated including alternate guiding and/or conveyance mechanisms, such as rollers, bearings, slides, or any other suitable conveyance means functionally equivalent to wheels.  
         [0034]     The lift frame  60  may also include a mechanism or lifting unit  82  that actuates the cradle assembly  100 . The lifting unit  82  may include a motor and gear reducer  83 , drive sprockets  84 , drum sprockets  86 , linkage  88 , drum shafts  90 , shaft coupler  91 , bearings  92 , drums  94 , cable  96 , and lead blocks  98 . The motor and corresponding gear reducer  83  drive the drive sprockets  84  that in turn drive drum sprockets  86  via linkage  88 . The drum sprockets  86  may then be used to drive drum shaft  90  and the attached drums  94  to raise and lower the cradle assembly  100 . In one embodiment, the lifting unit  82  contains two drive shafts, each operating one of two sides of the cradle assembly  100 . Each drive shaft may be formed by connecting two drum shafts  90  via a coupler  91 . However, it is contemplated that a single continuous drive shaft may exist without the need for coupler  91 . Each drum shaft  90  may be constrained to lift frame  60  via bearings  92 . Accordingly, drums  94  may contain cable  96  or rope, which may be metal cable or rope, or any other commercially known product that can be used on a drum to raise and lower cradle assembly  100 , such as a polymeric fiber, or composite strap. The cables  96  may then extend from the drums  94  to vertical lead block  98 , which directs the cables  96  down to the cradle assembly  100 .  
         [0035]     The cradle assembly  100  may function to accept, carry, and release the boat  12 . As previously described, the cradle assembly  100  attaches to lift frame  60  via extendable supporting means such as tension-bearing cables  96 , chains, beams, rigid members, or any other means as is appropriate for use with the embodiments of the present invention. Accordingly, extending or retracting the supporting means will lower or raise the cradle assembly  100  respectively. As illustrated in  FIG. 6 , the cradle assembly  100  may comprise cradle supports  102  and a boat-support mechanism  106 , such as a boat sling  106 , which may include a plurality of straps  106 ′. The cradle supports  102 , which may be rigid steel beams, may also include pairs of wheels  104  rotatably connected to distal ends thereof. In one embodiment, the cables  96  run from each vertical lead block  98  mounted of the lift frame  60 , through the corresponding wheel  104 , and back to an anchor or clip  99  mounted on the lift frame  60 . In this manner, rotating the drum  94  in a first direction to extend the cable  96  will lower the cradle assembly  100 . Similarly, rotating the drum  94  to retract the cable  96  will raise the cradle assembly. The cradle supports  102  may be constructed of wood beams, steel, metal alloy, composite I-beams (S or W shapes), structural tees, angles, channels, tubing, or the like. In one embodiment, the boat-support mechanism  106  or boat sling  106  may be constructed of two straps  106 ′ each having two ends connected to the cradle supports  102 . However, any number of straps  106 ′ may be used to construct the boat sling  106  as is appropriate for use with the embodiments of the present invention. Each strap  106 ′ may be affixed at opposing ends of the cradle supports  102  via pins, clips, bolts or other fasteners. In one embodiment, the straps  106 ′ may be moveably connected to the cradle supports  102  by a movable constraint  108  such as a trolley  108 ′, wherein the moveable constraint  108  is capable of translating along cradle support  102  to allow boat lift  10  to accommodate differently sized boats.  
         [0036]     As mentioned, the cradle assembly  100  may include of a pair of boat slings  106 . The boat slings  106  may be fabricated from high strength polyester that is resistant to damage from abrasion and deterioration from water exposure. The boat slings  106  may also be fabricated from materials offering similar wear resistance like that of nylon. It is also contemplated that the boat sling  106  for carrying boat  12  may be comprised of other suitable means, including but not limited to, a heavy gauge net  106 ″ which may be coupled to connectors at its extremities. Like the straps  106 ′, such heavy gauge net  106 ″ may also be produced from nylon or high strength polyester. To assist the boat slings  106  in submerging rather than floating, weights  110  may be provided with the boat slings  106 . In one embodiment, weights  110  are sewn into packets provided in the boat slings  106 . The cradle assembly  100  and/or the weights  110  may not retain water when the boat  12  is lifted out of the water. In an alternate embodiment, the cradle assembly  100  may employ a rigid structure, as shown in  FIG. 7 , for lifting, supporting, and portaging the boat.  
         [0037]     With reference now to all of the Figures, in use the lift frame  60  of the boat lift  10  is positioned over the first body of water  14  thereby positioning the cradle assembly  100  over the first body of water  14 . The cradle assembly  100  may then be lowered into a position where the boat sling  106  and the corresponding weights submerge beneath the water. It is noted here that track  34  is cantilevered over the first body of water thereby allowing the boat sling  106  to be oriented so as to receive the boat  12  in a sideways manner. That is to say that the boat  12  may be maneuvered to juxtapose the port or starboard sides of the boat  12  to the barrier  18  and the boat lift  10 . The boat  12  may then be driven over the boat sling  106  for subsequent lifting and translating by the boat lift  10  in a manner consistent with the embodiments described herein. If straps are used, at least one of the straps can be adjusted to accommodate different length boats  12 . The boat  12  may then be translated over the barrier by engaging the lifting unit  82  to raise the boat  12  and laterally moving the lift frame  60 . During movement, the boat  12  may held at constant elevation above the surface of the barrier. Accordingly, the boat lift  10  may include a control unit that automatically adjusts the elevation based upon one or more sensors, not shown. After the boat  12  is lifted and successfully translated over barrier  18 , it can then be lowered into the second body of water  16  for navigation as desired in the second body of water.  
         [0038]     Although the invention has been described herein with reference to the present embodiments, it will become apparent to those skilled in the art that various modifications of the present embodiments of the invention as described herein can be made without departing from the spirit or scope of the invention as defined by the appended claims.