Abstract:
The present invention relates to a stationary boat lift comprised of a housing in which a boat is able to enter and exit with little difficulty. The boat lift allows a boat to bypass various barriers in a efficient and safe manner by vertically lifting the boat out of one body of water, translating the boat horizontally over a desired barrier, and then vertically lowering the boat into a second body of water.

Description:
This application claims the benefit of U.S. Provisional application Ser. No. 60/070,518, filed Jan. 6, 1998. This application is a continuation of U.S. application Ser. No. 09/205,862 filed Dec. 4, 1998 now U.S. Pat. No. 5,947,639, which application was timely converted from U.S. provisional application No. 60/070,518 filed Jan. 6, 1998. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a lifting apparatus used to portage a boat. More specifically, the present invention relates to a mechanism for vertically lifting a boat out of one body of water, transferring the boat horizontally over a barrier, and then vertically lowering the boat into a second body of water. 
     BACKGROUND OF THE INVENTION 
     Known within the prior art are devices for lifting boats out of water for such purposes as making repairs, protecting boats from dock collision caused by tidal action, and preventing damage to a boat&#39;s hull from excessive exposure to water. U.S. Pat. No. 5,184,914 describes and shows a boat lift that consists of a frame which cradles and lifts a boat from the water by the 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, the lift may either raise or lower the boat to a pre-programmed elevation. 
     Both of these devices are useful for lifting boats out of water, but are both limited to lifting and lowering the boat in a vertical direction which is indicative of the general state of the art in boat lifting devices. The prior art fails to teach an apparatus that can both, lift and lower a boat in a vertical direction and transfer the boat in a horizontal direction. Applicant has discovered the need to transfer boats over barriers, such as water divider walls. In many areas salt water and fresh water are separated by various types of barriers. Barriers are needed to separate fresh water from salt water due to the various types of organisms, plants and animals why only survive in either salt or fresh water, but not both. Regardless of the need to isolate salt from fresh water, boats and other types of water vehicles still require access to and from these separate bodies of water. 
     Therefore, in light of the foregoing deficiencies in the prior art, Applicant&#39;s invention is herein presented. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a stationary boat lift which raises a boat in a vertical direction to remove it from one body of water, transfers the boat in a horizontal direction over a barrier and then lowers the boat into a second body of water. The preferred embodiment of the present invention is comprised of a housing in which a boat is able to enter and exit with little difficulty. The housing is built over the barrier which the boat is to traverse so that the barrier is centered within the housing. Attached to the top portion of the housing is a hoist capable of movement in a straight path parallel to the length of the housing. The hoist has an outer frame which supports its various components. The hoist includes two motors, one which drives the lifting components and a second which drives the translation components. 
     After the boat has entered the lift it is positioned over a pair of slings which are placed under the boat. One sling is located near the bow or front portion of the boat while the second sling is located near the stem or rear portion of the boat. The slings are fastened between two support beams which are lowered or raised by cable wires connected to cable spindles which are mounted to the hoist. The spindles and their respective drive shafts rotate in a clockwise or counterclockwise direction depending on whether the boat is to be lowered or raised. 
     Once the boat is in a fully raised position, the boat lift translates the boat in a horizontal direction over the particular barrier located within the housing. Translation of the hoist is controlled by a second motor which powers a set of flanged wheels to move the hoist back and fourth in a horizontal direction. An operator is able to easily control the functioning of the boat lift through a control panel located either within or outside of the housing. As a result, passengers never need to exit the boat during the lifting process. 
     It is therefore an object of the present invention to provide a new and improved boat lift capable of lifting a boat in and out of water in both a vertical and horizontal direction. 
     It is a further object of the present invention to provide a boat lift which can be easily and safely operated by one or more individuals, who are operators of the boat and not require an operator full time for the boat lift. 
     It is still a further object of the present invention to provide a boat lift which allows a boat to be lifted and carried over various types of barriers. 
     It is yet another object of the present invention to provide a boat lift in which passengers may remain on board the boat while it is being portaged over a barrier. 
     These, along with other objects and advantages of the present invention will become more readily apparent from a reading of the detailed description taken in conjunction with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front elevational view of the boat lift apparatus of the present invention; 
     FIG. 2 is a side elevational view of the boat lift apparatus shown in FIG. 1 as a boat initially enters the housing of the boat lift; 
     FIG. 3 is a side elevational view of the boat lift apparatus shown in FIG. 1 as a boat exits the housing after being portaged over a barrier; 
     FIG. 4 is a bottom perspective view of the hoist incorporated into the boat lift apparatus; 
     FIG. 5 is a top plan view of the hoist incorporated into the boat lift apparatus; 
     FIG. 6 is a front elevational view of the hoist shown in FIG. 5; and 
     FIG. 7 is a side elevational view of the hoist shown in FIG.  5 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the following description of a preferred embodiment 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 in a horizontal direction over a barrier and then lowering the boat into a second body of water. Referring to FIG. 2, boat lift  10  consists of a frame comprised of a plurality of vertical and horizontal supports,  32  and  40  respectively, which support and maintain roof  42  above the intersection of a first and second body of water,  18  and  20 , divided by barrier  16 . Many areas having both salt and fresh water bodies must take care not to allow the two bodies of water to mix thereby contaminating the fresh water. Various types of organisms, plants and animals can only survive in either salt water or fresh water. To accomplish this many communities construct barriers separating the two bodies of water. The down side to using barriers is that boats are prevented from freely traveling between the fresh and salt water bodies. 
     In FIG. 2, boat  12  enters boat lift  10  at either one of two ends via either first body of water  18  or second body of water  20 . Channel  14  of boat lift  10  is divided into two sections by barrier  16 . Barrier  16  is located between and divides the first and second bodies of water,  18  and  20  respectively, at approximately the middle of the housing effectively creating two isolated bodies of water. The housing of boat lift  10  is constructed over barrier  16  and along channel  14  with a plurality of vertical supports  32  extending from both sides of channel  14 . Vertical supports  32  are coupled to a plurality of horizontal supports  40  (shown in FIG. 2) which in turn are coupled to and support roof  42 . In the preferred embodiment, both the vertical and horizontal supports,  32  and  40 , are steel I-beams which provide the necessary strength and dependability to portage large, heavy boats. Applicant also envisions the present invention being constructed from bricks, strong woods, composites or numerous other materials common in construction so long as the materials provide the requisite strength and durability. 
     Coupled between horizontal supports  40  is hoist  34  (see FIG. 1) which translates along horizontal supports  40  from one end to the other of boat lift  10 . As will be explained in more detail later, power distribution bus  30  provides (shown in FIG. 4) electrical power to various motors, one of which allows hoist  34  to translate horizontally along the length of boat lift  10 . Attached by wire ropes  38  and disposed beneath hoist  34  are distribution supports  26  and  28  (see in FIGS. 1,  3  and  4 ). Due to the enormous stress which boat lift  10  is subjected due to the weight of a typical boat, distribution supports  26  and  28  are comprised preferably of steel I-beams which support and evenly distribute the weight of boat  12 . Attached to both ends of each distribution support,  26  and  28 , are eye hoist hooks  52 . To create a cradle for carrying boat  12  over barrier  16 , strap-like slings  22  and  24  are coupled between opposing eye hoist hooks  52 . Sling  22  is coupled between eye hoist hooks  52  located on a first end of both distribution supports  26  and  28 , while sling  24  is coupled between eye hoist hooks  52  located on the second end of both distribution supports  26  and  28 . Slings  22  and  24  preferably are fabricated from high strength polyester which is resistant to damage from abrasion and deterioration from exposure to water, particularly salt water. The slings  22  and  24  may also be fabricated from materials offering similar damage resistance, such as nylon and the like. It is also possible that the cradle for carrying boat  12  may be comprised of other suitable means, including but not limited to, a heavy gauge net which may be coupled at its extremities to hoist hooks  52 . Like the slings,  22  and  24 , such net may also be produced from high strength polyester or nylon. In order that the slings  22  and  24 , or alternatively a net, will readily submerge rather than float, lead weights are provided with the slings  22  and  24  and the net. In the case of the slings  22  and  24 , the lead weights are sewn into packets provided in the slings  22  and  24 . 
     The actual operation of boat lift  10  can be more easily seen by referring to FIGS.  2  and  3 . In FIG. 2, boat  12  has entered boat lift  10  via first body of water  18 . Once boat  12  is cradled by slings  22  and  24 , hoist  34  (not shown) raises boat  12  vertically out of first body of water  18 . Electric motors included as part of hoist  34  raise boat  12  with wire ropes  38  and pulleys  36  which are coupled to either end of distribution supports  26  and  28 . A user controls the vertical and horizontal direction of hoist  34  through control panel  44  which includes a number of switches and/or control levers as is known in the art. Electrical power is supplied to boat lift  10  and hoist  34  through power distribution panel  46 . In FIG. 3, hoist  34  has now traversed the length of boat lift  10  horizontally carrying boat  12  over barrier  16 . Once over barrier  16 , hoist  34  releases wire ropes  38  in a controlled manner allowing pulleys  36  to lower distribution supports  26  and  28  and their respective slings  22  and  24 , thereby vertically lowering boat  12  into second body of water  20 . Boat  12  is now free to exit boat lift  10  and proceed from first body of water  18  into second body of water  20 . Boat  12  can just as easily travel from second body of water  20  to first body of water  18  by simply entering boat lift  10  from the opposite direction. 
     Hoist  34  will now be described in more detail with reference to FIGS. 4 through 7. As shown in FIG. 5, hoist  34  is made up of an outer frame portion comprised of two side frame members  100  and two end frame members  102  coupled to one another to create a rectangular frame. Further support is provided by an additional pair of elongated frame members  106  and a plurality of partial frame members  104  coupled within and to frame members  100  and  102 . In the preferred embodiment all frame members are comprised of steel I-beams, which again are used for their exceptional strength and durability. 
     The lifting capability of hoist  34  is provided by motor  148  coupled to drive gear reducer  150 , which is permanently positioned on top of mounting base  180  (also shown in FIGS. 4,  6  and  7 ) located near the center of hoist  34 . Mounting base  180  is coupled between elongated frame members  106  by common means such as welding and/or bolting. Extending from mounting base  180  is jack plate  184  (FIG. 5) which allows additional attachments to be fastened to hoist  34 . As the name implies, a jack of some type that for example could be used to remove a boat&#39;s motor could be coupled from jack plate  184  thereby making hoist  34  more versatile. Drive gear reducer  150  includes a pair of sprockets  152  and  154  coupled to either end of an axle extending from each of its sides. Motor  148  includes conduit box  174  (shown in FIG. 5) attached toward its rear portion for accepting and interfacing electrical power conductors (not shown) to motor  148 . 
     Coupled between side support members  100  and elongated support members  106 , near each of the four corners of the frame of hoist  34 , are drive shafts  178  having a spindle  186  attached on one end of each drive shaft  178 . On both ends of hoist  34  at a point between both elongated support members  106 , opposing drive shafts  178  are coupled together by roller chain couplings  170 . Also on both ends of hoist  34 , at a position adjacent each roller chain coupling  170  is a sprocket,  162  or  168 . Sprockets  162  and  168  are coupled to sprockets  154  and  152  of drive gear reducer  150  by drive chains  164  and  166 . Drive gear reducer  150  is configured such that whichever direction sprocket  152  rotates, sprocket  154  rotates in an opposite direction. Through this arrangement spindles  186 , located on a first side of hoist  34 , rotate in the direction opposite spindles  186  located on a second side of hoist  34 , which in turn raises or lowers the distribution supports ( 26  and  28 , not shown in FIG. 5) and the slings ( 22  and  24 , not shown). The configuration of drive gear reducer  150  and sprockets  152  and  154  is a significant improvement over hoists used in the prior art in that a single electric motor  148  controls the raising and lowering of both ends and/or sides of boat  12 . In the past, boat lifts typically employed two electric motors, one on either end of the hoist. Over time, despite the electric motors being identical, the characteristics of each motor will change slightly due to wear and tear causing them to rotate at slightly different speeds. This difference in rotational speed causes one end and/or side of a boat to raise or lower ahead of the other end and/or side preventing the boat from being maintained in the preferred horizontally level position during transfer from one body of water to another. Because gear drive reducer  150  includes two drive shafts  151 , each coupled to one of either sprockets  152  or  154 , which rotate in opposite directions and are driven by a single electric motor  148 , boat lift  10  raises and lowers boat  12  with fewer components while maintaining boat  12  in the preferred horizontally level position. 
     As shown more clearly from FIG. 4, a length of wire rope  38  is connected to each spindle  186 . As spindles  186  are rotated in a first direction they wind wire rope  38  onto spindle  186  thereby moving distribution supports  26  and  28  (only support  28  shown in FIG. 4) in an upward direction. When spindles  186  are rotated in a second direction they unwind wire rope  38  from spindle  186  thereby lowering distribution supports  26  and  28  in a downward direction. As slings  22  and  24  are coupled to distribution supports  26  and  28 , ultimately a boat being cradled by slings  22  and  24  will move vertically in one direction or the other based on the direction of rotation of spindles  186 . 
     Also shown in FIG. 4, the other end of wire ropes  38  not coupled to spindles  186  are instead coupled through first pulleys  36  then around second pulleys  37 , which are connected to partial frame members  108 . Couplings  48  are linked to first pulleys  36  through second couplings  50  which are connected at either ends of distribution supports  26  and  28 . The free ends of wire ropes  38  are fixedly coupled to partial frame members  108  (shown in FIG.  5 ). 
     Once boat  12  has been raised vertically into its upper most position, hoist  34  translates in a horizontal direction thereby moving boat  12  over barrier  16  to the opposite side of boat lift  10 . To accomplish horizontal movement, hoist  34  includes a pair of flanged wheels  172  coupled between a pair of axles  182  connected to one another by coupling shaft  188  (see FIGS.  5  and  7 ). Attached to the far end of one axle  182  is sprocket  176 . Electric motor  156 , including sprocket  158  coupled to the drive shaft of motor  156 , is permanently attached to the outer portion of one end frame member  102 , directly adjacent sprocket  176 . Sprocket  176  and sprocket  158  are coupled to one another by a drive chain (not shown) such that when motor  156  rotates, causing sprockets  158  and  176  to rotate, axle  182  rotates as well. Flanged wheels  172  rotate with axle  182  to drive or translate hoist  34  horizontally along horizontal supports  40  which act as a track for flanged wheels  172 . Located opposite of flanged wheels  172  and axles  182 , are flanged wheels  173  and axles  183 . Unlike axles  182 , axles  183  are individually coupled between side frame members  100  and elongated frame members  106  so they spin freely as flanged wheels  173 , coupled to one end of axles  183 , roll across horizontal supports  40  during movement of hoist  34 . In the preferred embodiment only the one set of flanged wheels  172  is driven by motor  156 , but alternative embodiments are contemplated in which not only flanged wheels  172 , but also flanged wheels  173  are powered. In such event a second electric motor  156  may be provided to hoist  34 , and axles  183  will be coupled like axles  182  by a second coupling shaft  188 . 
     Referring to FIG. 4, both electric motors  148  and  156  receive power from power distribution bus  30  attached to and spanning the length of one horizontal support  40 . Motors  148  and  156  are electrically coupled by a cable to power distribution interface  54  mounted within the framework of hoist  34 . Extending downward from power distribution interface  54  are power conductors  56  which are connected to sliding power coupling  58 . Power distribution bus  30  acts as a track for power coupling  58  which slides back and forth along power distribution bus  30  while maintaining constant electrical contact. Because power distribution interface  54  is mounted to the frame of hoist  34 , as hoist  34  traverses horizontally, power conductors  56  move and drag or slide power coupling  58  along power distribution bus  30 . In this manner electricity is supplied to electric motors  148  and  156  without using long conductors and complicated conductor winding mechanisms. As shown in FIG. 4, power distribution bus  30  includes a plurality of grooves in which power coupling  58 , which also includes grooves, mates with to maintain constant electrical contact between the two. 
     FIGS. 6 and 7 further show the arrangement of components which make up hoist  34  and its framework. FIG. 6 shows sprockets  162  and  168  in relation to side frame member  100 . Coupled to both side frame members  100 , although only shown on one side, on both ends are flange bearings  214 . Drive shafts  178 , as shown by horizontally extending, parallel dashed lines in FIG. 7, are each coupled to individual flange bearings  214  which provide smooth and consistent rotation of the drive shafts. Referring again to FIG. 6, coupled to the underside of hoist  34 , shown in ghost lines, is work platform  216  which makes hoist  34  more versatile. Work platform  216  provides an area in which an individual can sit or stand in order to provide maintenance to hoist  34 . Platform  216  can also be used to mount further equipment such as additional winches or pulleys that can be used in portaging a boat. Also coupled to either end of side frame members  100  are pillow block bearings  212  which are used to provide fluid rotation to axles  182  and  183  which provide horizontal translation for hoist  34 . Axles  182  and  183  (not shown) are coupled to the underside of the frame of hoist  34  by shaft couplings  218 . 
     These and the other advantages and unique characteristics of the boat lift described with reference to the preferred embodiment provides a versatile and reliable apparatus to portage a boat. The foregoing description of preferred embodiment of the invention is merely an example, and the invention is not to be limited to the preferred embodiment, as many variations or modifications would be apparent to those skilled in the art based upon the principals of the invention as set forth herein.