U.S. patent application number 12/502697 was filed with the patent office on 2010-09-23 for boat lift.
Invention is credited to CURTIS BROWN.
Application Number | 20100239371 12/502697 |
Document ID | / |
Family ID | 42737788 |
Filed Date | 2010-09-23 |
United States Patent
Application |
20100239371 |
Kind Code |
A1 |
BROWN; CURTIS |
September 23, 2010 |
BOAT LIFT
Abstract
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.
Inventors: |
BROWN; CURTIS; (LEANDER,
TX) |
Correspondence
Address: |
MICHAEL O. SCHEINBERG
P.O. BOX 164140
AUSTIN
TX
78716-4140
US
|
Family ID: |
42737788 |
Appl. No.: |
12/502697 |
Filed: |
July 14, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61161649 |
Mar 19, 2009 |
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Current U.S.
Class: |
405/3 |
Current CPC
Class: |
B63C 3/06 20130101; E02C
5/00 20130101 |
Class at
Publication: |
405/3 |
International
Class: |
B63C 3/06 20060101
B63C003/06 |
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.
Description
[0001] 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 INVENTION
[0002] The present invention relates generally to vehicle lifts,
and more particularly to a mechanism for lifting boats.
BACKGROUND OF THE INVENTION
[0003] The 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.
[0004] 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.
[0005] Examples of such boat lifts are shown in the figures; an
overhead boat house lift is shown in FIG. 1 and a 4 (four) point
boat lift is shown in FIG. 2. As shown in FIG. 1, an overhead
boathouse lift 100 includes pulleys 102 that mount to the joists
104 or I-beams of an existing boathouse and utilize either a
plurality of slings 106 or a cradle to support the boat to lift it
out of the water. A cable drive system 108 is mounted to the upper
part of the boathouse. Cables are routed across the upper part of
the boathouse from the drive system 108 above the boat, to pulleys
102 on or beyond the width of the boat, and finally down to the
supporting sling 106 or cradle.
[0006] FIG. 2 shows a 4 point lift 200 to include 4 (four) vertical
beam structures placed near the sides of a boat dock, typically on
existing wooden pilings 202 used for supporting a walkway 206. In
some cases, as is the case shown in FIG. 2, the horizontal beam
structures are omitted in favor of the support offered by the
wooden pilings 202 themselves. Horizontal beams 204 rest on, or are
mounted to, the vertical beam structures or wooden pilings 202,
providing a fixed point for attaching cables 208. Vertical bumper
guards are sometimes required with a 4 point lift to prevent damage
to the boat or fixed structures when the boat "swings" in response
to windy conditions. Cable drive systems 212 are mounted on top of
pilings 202 on each side of the boat for the purpose of providing
even lifting of the boat. Freestanding lifts are similar to the 4
point lift, where the vertical beams themselves rest on the bottom
of the lake and reach from below the water line to above the boat
hull.
[0007] 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
FIG. 1, the cable drive system 108 is attached to a joist 104 of
the boathouse superstructure directly above the boat, and cables
are clearly seen extending downward from the roof of the boathouse.
Drive systems 212 of the 4 point boat lift of FIG. 2 are shrouded
by a cover, but are still clearly visible in that their locations
are not hidden from sight. Cables 208 are also clearly visible in
either a lowered position or a lifted position.
[0008] 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 FIG. 1 extend from pulleys or
rollers 102 mounted on the roof of the boathouse superstructure.
The pulleys 102 act as a pivot point with the weight of the boat in
the straps 106, creating a literal "swing" as the boat is in a
lifted position. The 4 point boat lift of FIG. 2 is in a lifted
position and cables 208 are long and easily seen and having an
upper pivot point by their connection to the horizontal arms 204,
again leading to a swing-like assembly
[0009] 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 INVENTION
[0010] In 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.
[0011] 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.
[0012] 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] 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:
[0014] FIG. 1 shows an isometric view of boathouse boat lift;
[0015] FIG. 2 shows an isometric view of a 4 (four) point boat
lift;
[0016] FIG. 3A shows an isometric view preferred embodiment of the
boat lift of the present invention in a lowered position
[0017] FIG. 3B shows the boat lift of FIG. 3A in a lifted
position;
[0018] FIGS. 4A and 4B show the position of the lifts of FIG. 3A
and FIG. 3B respectively, and additionally show a more clandestine
placement of the cable mounting points;
[0019] FIG. 5 shows one embodiment of components of a cable drive
system--a hydraulic cylinder and rod assembly, with attached pulley
blocks and cables;
[0020] FIG. 6 shows the hydraulic cylinder and rod assembly of FIG.
5, with extension ends;
[0021] FIG. 7 shows a support beam of a preferred embodiment, with
extension ends protruding from within its interior at each end;
[0022] FIG. 8 shows a front elevation view of a hydraulic cylinder
and rod assembly in operation as a cable drive system in an
extended, or lifted, configuration;
[0023] FIG. 9 shows a front elevation view of the hydraulic
cylinder and rod assembly of FIG. 8, but in a retracted, or
lowered, configuration;
[0024] FIG. 10 is an end elevation view of the support beam of FIG.
7;
[0025] FIG. 11 is an end elevation view of the extension end of
FIG. 10 as mounted within the interior of the support beam
[0026] FIG. 12 is an isometric view of a hydraulic cylinder and rod
assembly assembled with pulley blocks at each end;
[0027] FIG. 13 is a more detailed isometric view of one side of a
pulley block of FIG. 12;
[0028] FIG. 14 shows another side of the pulley block of FIG.
13;
[0029] FIG. 15 is a planar view of the hydraulic cylinder, rod and
pulley block assembly of FIG. 12;
[0030] FIG. 16 is the hydraulic cylinder, rod and pulley block
assembly of FIG. 15, with cables;
[0031] FIG. 17A is a front elevation view of another preferred
embodiment of a cable drive system for use with the present
invention--utilizing inter-cogged cable spools;
[0032] FIG. 17B is a perpendicular view of the view of the cable
drive system of FIG. 17, showing a motor that provides rotational
force to one of the spools;
[0033] FIG. 18A is a cutaway view of a lead screw embodiment of the
present invention;
[0034] FIG. 18B is a close-up view of the embodiment of FIG.
18A;
[0035] FIG. 19 is a front elevation view of another preferred
embodiment of a cable drive system for use with the present
invention--utilizing two axially opposed hydraulic, rod and pulley
block assemblies;
[0036] FIG. 20 is a front elevation view of another preferred
embodiment of a cable drive system for use with the present
invention--utilizing two axially opposed hydraulic, rod and pulley
block assemblies each mounted within separate extension members,
both extension members attached to the interior of a support
beam;
[0037] FIG. 21 shows a hook latch and wedge bolt, the hook latch
mounted on or about the support beam of the present invention, and
the hook latch having a pin for engaging with the hook latch;
[0038] FIG. 22 shows the hook latch engaged with the pin in the
wedge bolt for retaining the support beam in a lifted
configuration;
[0039] FIG. 23 shows a perspective view of a preferred embodiment
of the present invention, with two support beam assemblies arranged
near a boat dock to support the front and rear of a boat;
[0040] FIG. 24 shows a similar embodiment of FIG. 23, with an
additional support beam placed aft to support the typically heavier
portion of a boat;
[0041] FIG. 25 shows an embodiment similar to that of FIG. 23, with
the exception of being arranged as a stand-alone assembly without
being mounted directly to a boat dock; and
[0042] FIG. 26 shows a preferred embodiment similar to FIG. 23, as
partially mounted to a walkway structure.
[0043] 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 EMBODIMENTS
[0044] In 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.
[0045] 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.
[0046] 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).
[0047] Referring to FIG. 3A, a boat lift 300 embodying the present
invention is shown to generally include a support beam body 302,
out of which cables 306 (external lengths shown only) extend to
attach at their external ends to elevated fixed points 330 so that
when the external cable lengths are shortened, the support beam
body 302 and all attached components are raised up to a position
shown by FIG. 3B. In the embodiment depicted in FIG. 3A and FIG.
3B, the fixed point 330 to which the external ends of the cables
306 attach are located on stationary posts 322, the cables being
held in place by a wedge socket assembly 308. The support beams
302, as well as other components of the present invention, may
preferably be made of aluminum or stainless steel to resist
corrosion.
[0048] 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 FIG. 3A, telescope into the interior of the
support beam body 302 to adjust for a particular width defined by
the distance between stationary structures such as posts 322 on
either side of the support beam 302, or by the width of the vehicle
to be supported on the support beam 302. In other words, the width
defined by the cables 306 that extend from the support beam
assembly to the elevated fixed points 330 is preferably greater
than or at least the width of the boat to be supported by the boat
lift 300.
[0049] 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.
[0050] 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 FIG. 3A, for example, the power unit 312 is
placed upon a walkway 324. Other preferred locations may include
more clandestine locations, such as beneath the walkway. The
support beam 302 is shown as having a generally square-shaped and
elongated cross section. Other shapes of elongated support beams
including, for example, those with cross sections which are round
or cylindrically-shaped are considered within the scope of a
support beam usable with this and other embodiments. Whether
square, cylindrical, or any other shape, those support beams which
include an enclosed interior are termed "tubular" herein.
Additionally, other preferred shapes of support beams may include
"I-beams" or the like which do not have an enclosed interior, but
generally have an "I" shaped or "T" shaped cross section, for
example, and are also considered within the scope of the present
application. In these latter shaped embodiments of support beams,
the drive components attached to the support beam on any suitable
surface of the support beam, albeit not within an interior.
[0051] 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.
[0052] 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 FIGS. 4A and 4B.
Whereas the boat lift 300 of FIG. 4A is shown in a lowered position
for accepting a boat upon its hull skid supports 316, FIG. 4B shows
the support beam 302 in a raised or lifted configuration for
lifting the supported boat above the water line 326. In this raised
position, the boat lift 300 is more stable in comparison to the
raised position of prior art boat lifts because the minimal slack
permitted by the short cable length between cable pivot points 330
reduces the propensity for swinging commonly noted in prior art
boat lifts. Additionally, because very little cable length is
observable in the raised position, a cleaner aesthetic appearance
is achieved. Further adding to the clean appearance, the mounting
bracket 322, post structure or any other suitable mounting point
for the cable can be very low profile, as opposed to prior art boat
lifts that typically require fixed cable mounting points or pillars
that extend far above the water line 326 as shown in as shown in
FIGS. 1 and 2.
[0053] A preferred cable drive system is generally shown in FIG. 5.
A hydraulic cylinder and rod (or piston) assembly 500 for
withdrawing and extending cable from within or about the support
beam body (as shown by the dashed lines) generally includes a
hydraulic cylinder 508, an operatively and slidably affixed
hydraulic rod 510, and attached pulley block assemblies 502 at each
end of the hydraulic cylinder and rod assembly, one affixed to the
cylinder 508, and another affixed at the opposite end of the
assembly to the rod 510. Pulley block assemblies are discussed in
greater detail below. As more particularly shown in FIG. 16, two
cables are employed, one (reference numeral 1600) of which is fixed
to the pulley block by clamp 1602 and spans the block back and
forth 2 times before exiting the assembly and proceeding at its
external end to an external fixed point (as shown in FIGS. 3A-3B).
A second cable 1601 is attached to the hydraulic cylinder, rod and
pulley block assembly in a similar fashion, wrapping around the
assembly 2 times before exiting the assembly at the opposite end as
did the first cable 1600. As described below, this arrangement
whereby the cables are wrapped back and forth over the pulleys
multiplies the corresponding vertical height displacement that
results from the extension of the hydraulic rod
[0054] FIG. 12 shows a more detailed view of the cable drive
components assembly 1200 which includes the combined components of
the hydraulic cylinder 1202, rod 1204 and pulley block 1206.
Particularly apparent in FIG. 12 are the pulleys 1210 and cable
grooves 1208 of the pulley blocks 1206. Although cable grooves 1208
are shown to be substantially parallel to the long axis of the
hydraulic cylinder, because the cables do not actually travel
perfectly parallel across the assembly of the cable drive assembly
1200 (as particularly shown in FIG. 16), the groves 1208 may be
canted to reflect the actual direction of the cables across the
assembly 1200. The canting of the groves 1208 to be slanted
slightly toward a lateral side of the assembly will reduce the wear
on the cables, as will be appreciated by one of ordinary skill in
the art. Also shown in FIG. 12 are hydraulic fluid input and output
flanges 1212.
[0055] The operation of a preferred hydraulic cylinder and rod
assembly for cable manipulation is more clearly shown in FIG. 8 and
FIG. 9. In FIG. 8, the rod 804 of the hydraulic cylinder, rod and
pulley block assembly 800 is extended from the cylinder 802. The
cables 808 are operatively routed around pulleys of the pulley bock
assemblies 806 and the length of cable around the assembly 800 is
increased. Cables 808 extend from the cylinder, rod and pulley
block assembly 800 through pulley bearing assemblies 810, and are
ultimately attached to fixed points (uppermost end of the cables
808). As shown in FIG. 8, the assembly 800 is in a raised position
when a reduced length of cable extends from the pulley bearing
assemblies 810 and the fixed points 812, while the assembly 800 as
shown in FIG. 9 is in a lowered position when an increased length
of cable extends from the pulley bearing assemblies 810 and the
fixed points 812. In FIG. 9, the rod is retracted into the
cylinder, shortening the length around the cylinder, rod and pulley
block assembly 800, and increasing the length of cable between the
pulley bearing assemblies 810 and the fixed points.
[0056] 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.
[0057] 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 FIGS. 5-7, the
hydraulic cylinder and rod assembly 500 can be attached inside a
squarely-shaped and hollow support beam 700 so that the support
beam 700 encapsulates the cylinder and rod assembly 500 with
attached pulley block assembly 502 within its interior but allows
cables 504 to exit the support beam 700. In this fashion, the
cylinder and rod assembly 500 and pulley block assembly 502 are
essentially hidden from sight. It should be understood, however,
that a support beam need not encapsulate the cable drive system.
That is, the cable drive system may be connected to the support
beam's exterior or the support beam may also take the form of an
I-beam or other structure that the cable drive system components
are attached to, as long as the cable drive system is allowed to
move with the beam.
[0058] 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 FIGS. 17A through 20. FIG. 17A shows a
preferred spool-type embodiment 1700 as generally including two
cogged spools 1702 with intermeshing cogs 1704 axially extending
about their circumferences. The spools are preferably located
within the interior of the support beam body 1706 and are rotatably
affixed to the support beam 1706 so that attached cables 1708 can
be wrapped around them as shown in the FIGS. Both of the cogged
spools 1702 may be powered, but both cogged spools may turn if only
one of the two cogged spools 1702 is powered provided that the
other non-powered spool is connected to the powered spool. As shown
in FIGS. 17A and 17B, the cogs 1704 are intermeshed so that the
motion of one spool 1702 engenders motion of the other spool 1702.
In this embodiment as illustrated, the spools 1702 would rotate
axially in opposite directions in operation. To this end, a power
unit 1710 drives only one such spool. However, it should be
understood that any plurality of gearing between the two spools
could cause the rotational directions to be similar. Alternatively,
gearing could be used to multiply motion to the spools using known
gearing arrangements, as is appreciated by those of ordinary skill
in the art.
[0059] Another preferred embodiment is shown in FIG. 18A and FIG.
18B where the cable drive system comprises a screw-type assembly.
Lead screw assembly 1800 generally includes a centrally placed
power unit 1810, which turns the lead screws 1802 on both ends of
the power unit 1810. Cables are attached to traveling blocks 1804,
which travel along the rotating lead screws 1802, drawing the
traveling blocks 1804 inward or outward with respect to power unit
1810 and, thus, withdrawing or extending the attached cables. FIG.
18B is an enlarged view of the center portion of the lead screw
assembly 1800 of FIG. 18A, showing how cable 1806 is preferably
attached to the traveling block 1804 by a clamp 1808 on the end of
the cable 1806. Also in this figure, it is shown that to ease
movement of the traveling blocks 1804 within the support beam 1706,
it is preferred that bearings 1814 are placed in contact between
the traveling blocks 1804 and the support beam body 1706. The
bearings 1814 may be ball bearings, roller bearings, or the
like.
[0060] Another preferred embodiment is shown in FIG. 19. In this
embodiment, dual opposing hydraulic assembly 1900 generally
includes two hydraulic cylinder assemblies 1902. The assemblies
1902 each include a hydraulic cylinder, hydraulic rod and pulley
block. As shown in FIG. 19, the assemblies 1900 are arranged
opposite to each other so that the rods extend in opposite
directions. This embodiment allows for greater lifting capacity of
the single support beam they are mounted in, and/or increased cable
withdrawal capacity because only a single cable is wrapped around
each assembly 1902. The single hydraulic cable drive embodiments of
previous figures typically require two cables to be wrapped around
the hydraulic cylinder, rod and pulley block assembly, thereby
allowing only half as many turns of cable as the embodiment 1900 of
FIG. 19.
[0061] Yet another preferred embodiment is shown in FIG. 20. Dual
extension hydraulic assembly 2000 generally includes two hydraulic
cylinder, rod and pulley block assemblies 2002 each placed within
extended extension members 2004, which extension members 2004 are
slidingly placed within the interior of a larger interior
dimensioned support beam 2006. In this embodiment, the width of the
boat lift is proportional to the extending and retracting of the
rods of the hydraulic cylinder, rod and pulley block
assemblies.
[0062] Other components may be desirable for use in a more complete
boat lift system in addition to the support beam. As shown in FIG.
7, a perforated bar 702 can be attached to the support beam 700 to
allow the easy attachment of components to the support beam body.
Such attachments may include, for example, boat hull skid supports
316 which are to contact the bull of the boat as shown in FIG.
3.
[0063] 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 FIG. 3, adjustable extension members 304 telescope
into the interior of the support beam body 302 to adjust for a
particular width defined by the distance between mounting brackets
(wedge socket assembly 308) on the stationary post 322 on either
side of the support beam 302. The width is preferably greater than
or at least equal to the width of the boat to be supported by the
boat lift 300. As described above, 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, pulley
bearing assemblies 320 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.
[0064] A perspective view of the extension member components is
shown in FIG. 6, where extension members 600 are located at distal
ends of the hydraulic cylinder assembly 500. As shown in FIG. 7,
extension members 600 protrude from the interior of support beam
700 and are provided to allow an adjustment of width of the support
beam 700. Extension members 600 preferably include pulley bearing
assemblies 506 to assist in reducing friction of the cables as they
are withdrawn and extended during the operation of the boat lift
assembly comprising the support beam 700. As the extension members
600 may be of a smaller outer dimensions than the inner dimensions
of the support beam 700, spacers 602 are provided to fill the gap
and preferably also provide bolt contact points 604 where bolts
contact that penetrate through the support beam 700 by through
holes 704 in the support beam 700. Through holes 704 or bolt
contact points 604 may be threaded holes or unthreaded as one of
ordinary skill in the art deems appropriate to assure a clamping
force to prevent the undesired movement of the extension members
600 once a desired width has been obtained.
[0065] Extension members 600 of FIG. 6 are also shown in FIG. 10.
From this end view of the support beam 700, the extension member
600 and the pulleys of the pulley block 502 are visible, with cable
504. Further, FIG. 10 illustrates the components of the extension
member 600, including the pulley bearing assembly 1008, which is
held in the body 1000 of the extension member 600 by a pulley axle
1012, which itself is held in place by a pin (cotter pin, for
example) 1010. FIG. 11 further shows fasteners, such as bolts or
1102, that are preferably provided to secure the extension member
for this purpose. FIG. 11, as well as FIG. 7, also shows a sleeve
1104 for accepting a transverse member, as described below.
[0066] The pulley blocks of FIG. 12 are shown in greater detail in
FIGS. 13 and 14. The cables are held in place as they pass around
pulleys 1210 by cables grooves 1208. Depth of the center wall 1214
is short of the cable grooves 1208, so not to hinder their purpose.
Four ball bearings 1300 are preferably placed in spherical detents
at the corners of the body of the pulley block assembly 1206 so
that when the pulley block assembly 1206 is located within the
interior of the support beam, the bearings reduce friction of
movement. Preferably, eight (8) ball bearings 1300 may be used.
This is useful when the rod 1204 is being extended or withdrawn,
and also serves to prevent binding of moving components within the
support beam due to the weight of a supported boat (which would
result in the pulley blocks 1206 twisting within the beam).
[0067] FIG. 15 shows, in a planar view, the hydraulic cylinder, rod
and pulley block assembly of FIG. 12. As shown in FIG. 16 an end
clamp 1602 can be used to secure one end of a cable to the cable
drive system assembly 1200. The end clamp 1602 is placed on the end
of a cable 1600 and the cable is drawn through a hole or groove of
the pulley block 1208. As readily understood by one of ordinary
skill in the art, the end of the cable 1600 with the end claim 1602
is prevented from being pulled through the hole or groove in the
pulley block 1208.
[0068] As mentioned above in discussion of FIGS. 3 and 4, a latch
including a hook attached to the support beam and/or extension
members may be used to retain the support beam in a lifted position
while relieving tension from the cables and pressure on the drive
system components. FIG. 21 illustrates a preferred embodiment for
this utility. A hook 2102 is swinglingly attached to the extension
member 2112, which is attached to the support beam 2110. The hook
2102 latched upon the pin 2114 emerging from the cable wedge bolt
assembly 2116, as shown in FIG. 22. Preferably, an arm 2104 is
mounted on the perforated beam 2108 and attached to the hook 2102
to pull it toward the center of the support beam assembly to more
easily engage the pin 2114. The hook 2102 may preferably have a
rounded outer circumference to allow its displacement upon contact
of a properly placed pin 2114, as will be appreciated by those of
ordinary skill in the art. Also preferably, a spring 2106 is placed
between the hook 2102 and the perforated beam 2108 to exert outward
force on the hook 2102 for positive engagement on the pin 2114.
FIGS. 21 and 22 also more clearly show the wedge socket 2116 for
fixedly attaching one end of the cable, 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.
[0069] FIG. 23 shows a perspective view of a preferred embodiment
of the present invention, with two support beam assemblies arranged
near a boat dock 2302. In this embodiment, one support beam
assembly 2306 is placed aft to support the rear of a boat, while
another 2304 is placed fore to support the front of a boat. In the
embodiment shown in FIG. 23, the fore and aft support beam
assemblies are connected to each other by transverse members 2308.
The transverse members 2308 are preferably hollow and act as a
conduit for hydraulic or electrical lines (not shown) providing
power from the power unit (not shown) and the cable drive systems
of the respective support beams. As shown in the embodiment of this
figures, the cables are stationarily mounted (preferably via wedge
socket assemblies discussed above) to support structures of the
boat dock on both sides of the boat lift assembly.
[0070] FIG. 24 shows a similar embodiment to the one shown in FIG.
23, with an additional support beam 2402 placed aft (so that there
are a total of 3 support beams) to support the typically heavier
portion of a boat. Most boats include at least one engine to
provide propulsion to the boat through the water. That engine is
typically placed toward the rear, or stern, of the boat. This
configuration tips the balance of the boat toward the rear. The
placement of an additional support beam toward the rear of the boat
lift assembly provides a more even lifting force.
[0071] 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 FIG. 25, where members 2502 are part
of a stand-alone boat lift assembly 2500. Preferably, the
stand-alone support members 2502 are adjustable in length so that
they seat on a lake floor (or other water body floor) and provide
an attachment point for the cable so that the boat may be
adequately lifted out of the water.
[0072] 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''.times.12''.times.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.
[0073] 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 FIG. 26. In this location, one
side of the boat lift attaches to the walkway supporting structures
while the other side may be attached to another structure or simply
utilize a stand-alone support structure, as more prominently shown
in FIG. 25.
[0074] 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.
[0075] 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.
* * * * *