BOAT LIFT
An apparatus and method are described for lifting a boat out of water. An improved boat lift having at least one support beam upon which the weight of a boat rests, the support beams having an interior wherein components of a cable drive system are mounted, provides lifting force through operation of the cable drive system, which withdraws the support cables to within the interior of the support beams, the cables attached at one of their ends to fixed points external to the beam.
This application claims priority from U.S. Provisional Application 61/161,649, filed Mar. 19, 2009, which is hereby incorporated by reference.
TECHNICAL FIELD OF THE INVENTIONThe present invention relates generally to vehicle lifts, and more particularly to a mechanism for lifting boats.
BACKGROUND OF THE INVENTIONThe cleaning, repairing and storing of a boat is most effectively performed by lifting the boat out of the water. To this end, boat lifts have been valuable and widely used. However, they tend to be unsightly, unstable and functionally inefficient.
A typical boat lift employs several pulleys and cables mounted overhead the boat, with the lifting mechanism (cable drive system) in an attic or upper part of an overhead dock or vertical beam structure. In these systems, cables extend from the overhead drive mechanism down to the boat support structure in the water. Not only are the cables unsightly, but so are the drive mechanisms; if they are not hidden in an overhead attic, they are mounted in plain view to a vertical beam structure or on a boat walkway. In addition, they are unstable because the cable lengths from the overhead system to the boat remain long, so that the boat tends to swing and sway in the wind particularly with the boat out of the water and in a raised position on the lift. Further, because of their structural designs, typical boat lifts are not able to provide lifting force proportional to the balanced weight of the lifted boat and so the boat may rise unevenly.
Examples of such boat lifts are shown in the figures; an overhead boat house lift is shown in
A common complaint of these boat lifts is that the cables and drive system components are unsightly. In the arrangements stated above, the lifting mechanisms (i.e. cable drive systems) are attached far above the boat. The cables extend from the overhead drive systems down to the boat support structure in or near the surface of the water when the boat lifts are in a lowered position and remain visible even with the boat in a raised or lifted position on the boat lift. In the case of the boathouse lift of
Another disadvantage of prior art boat lifts is that they are unstable because the lifted boats tend to swing and sway in the wind due to the long cable length remaining between fixed points on the boat lift, even with the boat in a lifted position. Even in a lifted position, cables 110 of
Further, because of their structural designs, typical boat lifts are not able to provide lifting force proportional to the balanced weight of the lifted boat and the boat may lift unevenly.
SUMMARY OF THE INVENTIONIn accordance with the invention, many problems of prior art boat lifts are solved by mounting components of a cable drive system or mechanism to the support beams upon which the weight of the boat rests, and providing lifting force by withdrawing support cables within or around the cable drive system components, the cables attached at their external ends to fixed points external to the beam such that operation of the drive system causes movement of the support beams and attached drive system components.
In this way, the present invention provides a cleaner, more aesthetically pleasing structure because as the boat is in a lifted position, the support cables are nearly unseen, as are the drive system components. Further, it provides more stability, because in a lifted configuration, less cable length exists between attachment or contact points, reducing a “swinging” effect most notably observed in prior art boat lifts. Still further, it provides a more self-contained and inclusive support and cable drive mechanism assembly, allowing more versatility in the positioning of the support beams along the length of a boat, and thus, applying the lifting force in a more balanced manner.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
For a more through understanding of the present invention, and advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTSIn accordance with at least one embodiment of the present invention, the problems of unsightliness, instability and functional inefficiency are solved by placing the components of a lift mechanism within the interior of hollow support beams upon which the weight of the boat rests, and providing lifting force by withdrawing support cables to within the hollow support beams, the external ends of the cables attached to fixed points.
In this way, the embodiment provides a cleaner, more aesthetically pleasing structure because as the boat is in a lifted position, the support cables are nearly unseen, as are the drive system components. Further, it provides more stability, because in a lifted configuration, less cable length exists between attachment or contact points, reducing a “swinging” effect most notably observed in prior art boat lifts. Still further, it provides a more self-contained and inclusive support and cable drive mechanism assembly, allowing more versatility in positioning the support beams, and thus, the lifting force.
A boat lift embodying the present invention generally includes a support beam member with a cable drive system preferably placed inside the support beam. Alternatively, the cable drive system may be placed on the exterior of a support beam, as long as it is attached to the support beam so that it moves with the support beam as a unit. The cable drive system provides lifting force by engendering vertical motion of the support beam to which it is attached. Because the drive components are within or along the support beam used to lift up a boat, the drive components preferably function under water. In the preferred embodiments shown in the figures and described below, cable drive systems generally operate by withdrawing cable length within or along the body of the support beam, thereby shortening the length of the cable extending beyond the body of the support beam. Because the exterior cable ends are attached to a fixed point, such as a dock or stationary post, the reduction in cable length outside the support beam causes the support beam to be pulled up toward the fixed point of the attached cable drive system, thus raising any structure being supported by the support beam (e.g. a boat).
Referring to
Discussed in greater detail below, additional components may be preferred to aid in the operation of lifting a supported vehicle. Such additional components may include adjustable extension members 304 (described in greater detail below) which, in the embodiment of
Another additional component may include a perforated bar for easily attaching other components. For example, the support beam 302 is adapted for supporting the weight of a boat and preferably has a perforated bar 318 attached to its upper surface to allow the convenient attaching of hull skid supports 316 which are to contact the hull of the boat. One of ordinary skill in the art will appreciate that a perforated bar allows fasteners such as bolts and the like to attach other components that have corresponding holes such that the fastener aligns through both the holes of the perforated bar and the holes of the other component to matingly engage them.
The support beam is raised and lowered by a cable drive mechanism or system that withdraws cables 306 into the interior of the support beam 302. To this end, components such as pulley bearing assemblies 320 located at both ends of the support beam body 302 mounted on the extension members 304 are preferred to assist the cables in retracting and extending with minimal friction. A power unit 312, preferably a positive displacement hydraulic pump, supplies hydraulic fluid to cable drive components inside the support beam 302 of the cable drive system through hydraulic line 314. The power unit may be placed in a myriad of locations where one of ordinary skill in the art would find readily suitable. As shown in
Two or more support beams may be employed in a boat lift system for more evenly supporting the weight of an elongated vehicle such as a boat. The support beam positions are adjustable along the length of the particular boat upon installation because they tend to behave as separate lifting units and can be placed where needed. A typical preferred support beam assembly (a single support beam) has a capacity of about 5,000 lbs. (more typically 4,000-5,000 lbs.). In order to support more weight, one or more additional support beam assemblies may be added to the boat lift system. For example, if a user was required to lift a 20,000 lbs. boat, 4 standard beams could be used. If after installation of the boat lift, more lifting capacity is required, a user could add one or more support beam assemblies to the existing boat lift without needing to tear out the existing lift and install a completely new lift. The user only need connect the new support beam assembly to the power (hydraulic) supply and the external ends of the cables to fixed points as done with the other support beam assemblies.
It should be appreciated by those of ordinary skill in the art that the mounting point of the cable to an external, fixed point may be nearly anywhere above the vehicle to be lifted, whether it is in a visible location or a hidden one. It is preferable that, to provide an extra measure of cleanliness to the installation of the boat lift of the present invention, the cable be mounted in a less-observable location, such as beneath a walkway or boat dock structure, such as is shown in
A preferred cable drive system is generally shown in
The operation of a preferred hydraulic cylinder and rod assembly for cable manipulation is more clearly shown in
As described above, the extending and withdrawing of cables is performed by increasing or decreasing the distance between at least 2 sets of pulleys, either increasing or shortening the length of attached cables around a hydraulic cylinder, rod and pulley block assembly and, therefore, shortening or increasing the length of the attached cables extending from the assembly. A preferred embodiment of the cable drive system of the presenting invention utilizes a hydraulic cylinder and rod assembly to this end, by extending the rod 510 to increase the length of cable 504 wrapped around the cylinder and rod assembly 500, or retracting the rod 510 into the cylinder 508 to shorten the length of cable 504 wrapped around the assembly 500. Preferably, each cable is routed around the hydraulic assembly at least 2 times, such that every inch of extension of the hydraulic rod (or piston) results in 8 inches of cumulative external cable length shortening, or 4 inches of vertical height displacement. However, based on this exemplary description, skilled persons can readily design different cable and pulley configurations to vary the factor by which the piston travel relates to beam travel. Moreover, skilled persons will also recognize that the driving force requirement will increase as a smaller movement of the piston causes a greater movement of the support beam.
In some embodiments, a cable drive system, or at least the moving components of a cable drive system, is connected to, in or around a weight supporting member so that they move together. Preferably, the moving components of the cable drive system, such as a hydraulic cylinder, rod and pulley block assembly, are placed inside of a support beam body. Referring to
As mentioned above, many embodiments of cable drive systems are contemplated as within the scope and spirit of the present invention. Examples of the preferred embodiments of the present invention are shown in
Another preferred embodiment is shown in
Another preferred embodiment is shown in
Yet another preferred embodiment is shown in
Other components may be desirable for use in a more complete boat lift system in addition to the support beam. As shown in
Extension members can be attached to the support beam ends, preferably routing the cables through pulleys to reduce friction of cable movement while the support beam is being raised and lowered. Extension members also allow the ability to more finely adjust the effective width of the support beam so that the cables do not come in contact with the sides of the supported boat. As shown in the embodiment of
A perspective view of the extension member components is shown in
Extension members 600 of
The pulley blocks of
As mentioned above in discussion of
Although it may be typical that the boat lift of the present invention is mounted to an existing structure such as a boat dock or walkway, it is within the scope of the present disclosure that the boat lift of the present invention may be utilized as a “stand-alone” unit, where it is not attached to an existing structure but is otherwise attached to stand-alone support members. Such an embodiment is shown in
As an ancillary benefit to the modular nature of some embodiments of the present invention, the components can be easily packaged for shipping. Applicant has found that the components of embodiments of the present invention preferably can be packaged into a shipping box with dimensions of 12″×12″×10′ allowing the loading of several packages into a bed of a typical full size truck. Further, very little manpower (typically two men) is required to assemble the components of some embodiments of the present invention to complete an operational boat lift.
As will be appreciated by one of ordinary skill in the art from this exemplary description, the boat lift of the present invention may be mounted in a myriad of positions, configurations and locations. Another such location may be, for example, along one side of a walkway 2600, as shown in
The system describes herein provides the boating industry with a dependable solution for lifting a boat out of the water for docking and storage. The invention includes more than one novel and inventive aspect, and not all implementations will require all aspects to be combined in each implementation. Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. The invention is not limited to the use of boats or for the boating industry alone, but is useful in other areas, such as the automotive area, and in any environment where heavy equipment is desired to be moved from one position to another.
Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. For example, embodiments of the present invention are shown in the figures to be attached to a walkway or other existing structure. However, it is within the scope of the present invention that the embodiments may also be freestanding, that is, including a structure to mount fixed cable to or modifying an existing element of the embodiments without undue experimentation. Further, one of ordinary skill in the art will appreciate that while embodiments of the present invention are particularly drawn to boat lifts, it is within the scope of the present invention that embodiments are also capable of lifting other vehicles, such as cars, and can be used in other venues such as car garages. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
Claims
1. A boat lift, comprising:
- multiple support beams positioned apart to support a boat;
- at least one cable attached to each support beam and anchored to at least one fixed support to support the corresponding support beam;
- a lift mechanism attached to each of the multiple support beams, each lift mechanism when activated causing the cable to be drawn into or around the lift mechanism to cause the support beam along with the lift mechanism to move relative to the fixed support to raise the boat.
2. The boat lift of claim 1 in which the multiple support beams each include an interior and in which the lift mechanisms are positioned within the interiors of the support beams.
3. The boat lift of claim 1 in which the lift mechanism is hydraulically operated.
4. The boat lift of claim 3 further comprising a single hydraulic pump that provides hydraulic fluid to the lift mechanisms on all of the beams.
5. The boat lift of claim 3 in which each lift mechanism includes a hydraulic cylinder and a piston.
6. The boat lift of claim 3 in which each lift mechanism includes at least two hydraulic cylinders and pistons.
7. The boat lift of claim 3 in which each lift mechanism includes two spools that rotate to draw cable onto the spools, at least one of which is powered.
8. The boat lift of claim 1 in which the beam includes at least one telescoping section for varying the length of the beam to allow the beam to span slips of different widths.
9. The boat lift of claim 1 in which each lift mechanism includes:
- a hydraulic cylinder with a piston;
- at least two pulley blocks through which the cable is routed, one on either side of the hydraulic cylinder, so that extending the piston increases the distance between the pulley blocks to draw additional cable into or around the lift mechanism.
10. The boat lift of claim 9 in which each beam is tubular and in which the hydraulic cylinder and the at least two pulley blocks are positioned inside the tubular beam.
11. The boat lift of claim 10 in which one of the pulley blocks is fixed relative to the beam and the other one of the pulley blocks moves relative the beam as the piston moves in the cylinder, and further comprising a friction reducer to facilitate movement of the moving pulley block relative to the beam.
12. The boat lift of claim 11 in which the friction reducer comprises a bearing positioned on the pulley block.
13. The boat lift of claim 12 in which the friction reducer comprises a ball bearing positioned on at least four corners of the pulley block.
14. The boat lift of claim 1 further comprising a latch for latching the beams to the fixed support to relieve tension from the cable when the boat is supported above the water line.
15. The boat lift of claim 1 further comprising a single power source for supplying power to all the lift mechanisms, the power source distributing power to the lift mechanisms to ensure that all the lift mechanisms move the same amount regardless of different loads on the different lift mechanism to maintain the boat level in the boat lift.
16. The boat lift of claim 1 in which at least one fixed supports is positioned on a walkway.
17. The boat lift of claim 1 in which at least one fixed supports is positioned on a post extending from under the water line.
18. The boat lift of claim 1 in which the cable is anchored to the fixed support by looping it through an opening, with a wedge positioned within the loop to maintain the cable in the fixed support.
19. The boat lift of claim 1 in which the beam includes at least one extension section that extends from a main beam section and in which a hydraulic cylinder is positioned at least partly within the extension section.
20. The boat lift of claim 1 in which the beam includes two extension sections and the lift mechanism includes two hydraulic cylinders, with a hydraulic cylinder positioned at least partly within each extension section.
21. A lift system, comprising:
- a support beam for supporting a weight, the beam having an interior;
- one or more cables;
- a drive system for manipulating the one or more cables, wherein at least one component of the drive system is affixed within the interior of the beam, and a portion of the one or more cables affixed to the drive system such that such that operation of the drive system withdraws or extends the one or more cables into the interior of the beam.
22. The lift system of claim 21 in which the portion of the drive system affixed within the interior of the beam includes a hydraulic press having a movable piston, the one or more cables in contact with the piston.
23. The lift system of claim 21 in which the portion of the drive system affixed within the interior of the beam includes two or more spools, the one or more cables affixed to the two or more spools.
24. The lift system of claim 22 in which the two or more spools include intermating cogs, the cog of one spool in contact with the cog of the other spool, such that rotation of one spool causes equal but opposite rotation of the other spool.
25. The lift system of claim 23 having one cable, the cable having two opposite ends, each end affixed to a stationary object external to the interior of the beam, and wherein the portion of the cable affixed to the hydraulic press and movable piston is a center portion that encircles the hydraulic press and movable piston lengthwise, such that extension of the piston provides tension to the cable.
26. A method for lifting a boat, comprising:
- providing at least one hollow beam;
- providing a drive system having a plurality of components;
- affixing at least one of the plurality of components within the hollow of the beam;
- affixing at least one end of a cable to a stationary point external the hollow of the beam;
- arranging one or more cables with the drive system, such that operation of the drive system causes the withdrawing or extending of the cables from within the hollow beam; and
- operating the drive system.
27. A lift system, comprising:
- a support member for supporting a weight;
- one or more cables;
- a drive system for manipulating the one or more cables, wherein at least one component of the drive system is affixed to the support member, and a portion of the one or more cables affixed to the drive system such that such that operation of the drive system withdraws or extends the one or more cables, causing the support member and the attached drive system to move in accordance to the withdrawing and the extending of the cables.
28. The lift system of claim 27, wherein the drive system is mounted to a bottom side of the support member.
29. The lift system of claim 27, wherein the support member includes a reinforcement member to reduce flexing of the support member caused by a weight supported by the support member.
30. The lift system of claim 27, further comprising adjustable ends adjustably fastened to distal ends of the support member for adjusting the effective width of the support member.
31. The lift system of claim 27, further comprising rollers at distal ends of the support members, the rollers having a grove to support the cable, such that friction is reduced as the cable is moved during operation of the drive system.
32. The lift system of claim 27, wherein the drive system includes a hydraulic piston cylinder and piston.
33. The lift system of claim 27, wherein the drive system includes one or more spools having cylindrical surfaces, the one or more cables attached to the bodies such that rotation of the spools causes the cables to wrap around the bodies.
34. A cable fastening assembly comprising:
- a wedge having a groove along which a cable may align, the wedge having a tapered end and a wide end;
- a mount having a slot for accepting the wedge and having means for attaching to a surface, wherein the slot is large enough to accept the tapered end of the wedge, but prevents the wide end of the wedge to be pulled fully through the slot, and wherein providing a cable through one end of the slot and along the groove of the wedge, and providing force to the cable to position the wedge in the slot causes the cable to bind.
Type: Application
Filed: Jul 14, 2009
Publication Date: Sep 23, 2010
Inventor: CURTIS BROWN (LEANDER, TX)
Application Number: 12/502,697