The present invention generally relates to a lift system for watercraft. In particular, the present invention relates to a portable lift system for a pontoon boat that is carried beneath a deck of the pontoon boat.
It is desirable to lift pontoon boats out of the water when not in use so that the pontoons are not continually exposed to the water and to avoid disruption to the boat or its occupants as a result of waves or wakes from other passing watercraft. Conventional pontoon boat lifts are well known, but are stationary, i.e. typically adjacent to a dock, and include a platform which is submersible under the water below the pontoon boat. With the pontoon boat positioned above the platform, the platform is raised to elevate the pontoon boat above the water. To avoid damage during sub-freezing weather, docks and conventional lifts must be removed from the water before it freezes, usually well before the end of a normal boating season. Also, the effectiveness of conventional lifts can be impacted by fluctuations in the water level of a lake.
Thus, there is a need in the art for a portable lift system for pontoon boats that allows a pontoon boat to be lifted and securely held out of the water at any desired location.
The present invention comprises a pontoon lift system for a pontoon boat having a deck and a pair of pontoons supported at an underside of the deck. The lift system comprises a first and a second pair of lifts. The first pair of lifts are positioned between the pair of pontoons on the underside of the deck toward a first end of the pontoon boat. The second pair of lifts are positioned between the pontoons on the underside of the deck toward a second end of the pontoon boat. Each lift of the first and second pair of lifts has a mounting bracket secured to the underside of the deck and an actuatable leg connected to the mounting bracket. The legs are movable between a first position located proximate the underside of the deck and a second position spaced away from the underside of the deck. Each leg is movable independent from the legs of the other lifts.
While the above-identified drawing figures set forth preferred embodiments of the invention, other embodiments are also contemplated, as noted in the discussion. In all cases, this disclosure presents the present invention by way of representation and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of this invention. It should be specifically noted that the figures have not been drawn to scale, as it has been necessary to enlarge certain portions for clarity.
Each lift 24 generally comprises a channel 26, a motor 28, a screw 30, a leg 32, and a fulcrum arm 34. Channel 26 comprises a pair of spaced channel members 26A, 26B. Each channel member 26A, 26B includes a flange 36 for mounting channel 26 to support members 22. A motor mounting plate 38 is welded to channel 26 at a first end 40. Motor 28 is mounted to motor mounting plate 38 and is connected to a first end 29 of screw 30. A second end 31 of screw 30 is supported by a bearing 42 secured to a bearing plate 44 welded to a second end 46 of channel 26. A leg 32 is pivotally connected to wings 48 of motor mounting plate 38. Leg 32 is pivoted by a fulcrum arm 34, which has one end connected to leg 32, and a second end connected to a threaded follower 50 that is threaded onto screw 30. Threaded follower moves along screw 30 when motor 28 turns screw 30. When screw 30 is turned in a first direction, leg 32 is extended by virtue of the fulcrum arm connection such that leg 32 is radially spaced from screw 30. When screw 30 is turned in a second direction, leg 32 is retracted by virtue of the fulcrum arm connection such that leg 32 is proximate to screw 30.
Motor 28 is operatively connected to screw 30 and turns screw 30 to raise and lower leg 32. Motor 28 is mounted to motor mounting plate 38, which is welded to first end 40 of channel 26. In one embodiment, motor 28 is a reversible electric motor. In a preferred embodiment, motor 28 is a one-half horsepower motor manufactured by Bodine Electric Company capable of providing 400 lb-in. of torque. Motor 28 is preferably coated by waterproofing material.
Screw 30 is housed between channel members 26A, 26B. First end 29 of screw 30 is operatively connected to motor 28 by a drive coupling 52. Second end 31 of screw 30 extends to second end 46 of channel 26 and is supported by bearing 42. In one embodiment, screw 30 has a length of about 54.78 inches and is a threaded 1-4 2 Start Acme screw having an outside diameter of approximately one inch.
Threaded follower 50 is located between first and second ends 29 and 31 of screw 30 and is threaded onto screw 30. Screw 30 guides threaded follower 50 along the length of channel 26 when screw 30 is turned by motor 28.
Leg 32 comprises a pair of leg members 32A, 32B which are pivotally connected to wings 48 of motor plate 38 at a first end of leg 32. A brace plate 54 is welded to leg members 32A, 32B adjacent the first end of leg 32 and serves to provide support and stability to leg members 32A, 32B as leg members 32A, 32B pivot about first end 40 of channel 26. Leg brackets 56 are connected to leg members 32A, 32B below brace plate 54 and support a pivot tube 58 for connection of fulcrum arm 34. Leg 32 has a length sufficient to raise pontoon boat 12 above the surface of the water when leg 32 is fully extended relative to channel 26. When leg 32 is extended, lift 24 is supported on the bottom of the body of water by a pad 60 pivotally connected to a second end of leg members 32A, 32B by a pad pivot tube 62 and pad brackets 64. In one embodiment, the length of leg members 32A, 32B is about 65.56 inches. The preferable material for leg members 32A, 32B is aluminum.
Fulcrum arm 34 serves to raise and lower leg 32 as threaded follower 50 travels along screw 30. First end 66 of fulcrum arm 34 is pivotally connected to threaded follower 50 and second end 68 of fulcrum arm 34 is pivotally connected to pivot tube 58. In one embodiment, fulcrum arm 34 comprises a pair of fulcrum arm members 34A, 34B. Each fulcrum arm member 34A, 34B includes a plurality of holes 35 equally spaced along the length of fulcrum arm member 34A, 34B for weight reduction. A cross-piece may optionally be welded between fulcrum arm members 34A, 34B to maintain fulcrum arm members 34A, 34B at a constant distance from each other when fulcrum arm members 34A, 34B are extending and retracting leg 32. Each fulcrum arm member 34A, 34B has a length sufficient to extend leg 32 such that leg 32 is generally normal to channel 26 when fully extended. In one embodiment, fulcrum arm members 34A, 34B have a length of about 30.64 inches and structure holes 35 have a diameter of 1.5 inches. Fulcrum arm members 34A, 34B are preferably formed from aluminum.
Slider blocks 78 are housed in C-shaped track 70 of channel members 26A, 26B and are dimensioned to slide along C-shaped tracks 70 as threaded follower 50 moves along screw 30 to assist in smooth travel of threaded follower 50 along screw 30. In one embodiment, slider blocks 78 are made of a polymer material, preferably plastic. In an alternative embodiment, slider blocks 78 can be replaced with wheels, bearings, or any other known structure that functions to provide a smooth travel of threaded follower 50 along screw 30.
Threaded follower 50 is threaded onto screw 30 between channel members 26A, 26B. Threaded follower 50 generally comprises a drive block 80, drive screw 82, and anchor pin 84. Drive block 80 and drive screw 82 are located on screw 30. Anchor pin 84 fixes drive screw 82 relative to drive block 80 to prevent drive screw 82 from rotating relative to drive block 80 when screw 30 is rotated. Drive block 80 includes posts 86 (shown in phantom) which extend from opposite sides of drive block 80 toward C-shaped tracks 70. Each post 86 serves to pivotally connect fulcrum arm members 34A, 34B to threaded follower 50, and to connect threaded follower 50 to slider blocks 78.
Drive screw 82 is comprised of a head 94, a tubular body 96, and a bore 98 extending therethrough. Head 94 has an outer diameter larger than that of tubular body 96 and includes a notch 100 at a circumferential edge of head 94. Body 96 of drive screw 82 has an outer diameter sized to fit within bore 88 of drive block 80 and a length sufficient to extend through bore 88 of drive block 80. Body 96 has external threads that mate with a drive nut 102 when body 96 extends through bore 88 to secure drive screw 82 relative to drive block 80. Bore 98 of drive screw 82 is provided with internal threads that mate with the external threads of screw 30.
Each fulcrum arm member 34A, 34B has an opening 104 which receives a brass bushing 106 that is dimensioned to fit onto posts 86 of drive block 80. Each slider block 78 is provided with a hole 108 to receive an end portion of posts 86.
To assemble threaded follower 50 on screw 30, channel members 26A, 26B are secured to deck support members 22 of pontoon boat 12 with screw 30 supported at one end by bearing 42. Before motor mounting plate 38 is welded to channel 26 and screw 30 is secured to coupler 52, drive nut 102 is slid onto first end 29 of screw 30. Fulcrum arm members 34A, 34B are then connected to drive block 80 by positioning brass bushings 106 over posts 86 and slider blocks 78 are positioned to allow posts 86 to extend within hole 108 of slider blocks 78. Next, slider blocks 78 are positioned within C-shaped tracks 70 of channel members 26A, 26B while bore 88 of drive block 80 is passed over first end 29 of the screw 30.
Drive screw 82 is then threaded onto first end 29 of the screw 30. Once drive screw 82 is at the desired location on screw 30, bore 88 of drive block 80 is positioned over body 96 of drive screw 82. Drive screw 82 is rotated until notch 100 of drive screw 82 is aligned with lock pin hole 90 of drive block 80 and anchor pin 84 is press fit into lock pin hole 90 with a portion extending to engage notch 100. Drive nut 102 is then threaded onto the end portion of body 96 of drive screw 82 that extends from bore 88 of drive block 80 to prevent axial movement of drive screw 82 relative to drive block 80.
As shown in
With leg members 32A, 32B mounted to wings 48 of motor mounting plate 38 and channel members 26A, 26B, second end 68 of fulcrum arm members 34A, 34B are pivotally connected to leg members 32A, 32B.
As shown in
Each bore 160 of leg brackets 56 receives a portion of brass bushing 162 at the outward facing side of leg brackets 56. Leg brackets 56 are mounted to leg members 32A, 32B by aligning holes 164 in leg brackets 56 with complimentary holes 166 in leg members 32A, 32B and connecting the leg brackets 56 with bolts 168. After leg brackets 56 are mounted to leg members 32A, 32B, openings 158 of pivot tube 58 and brass bushings 156 are aligned with bores 160 of leg brackets 56, and leg shaft 170 is passed axially through leg brackets 56 and pivot tube 58.
Leg shaft 170 has an outer diameter sized to fit within brass bushings 156 and 162 and a length sufficient to extend through leg brackets 56 and pivot tube 58. Each side of leg shaft 170 has a threaded hole 172 with a depth and diameter to receive threaded bolts 174 and thereby secure fulcrum arm members 34A, 34B to leg members 32A, 32B.
To lower leg 32, motor 28 turns screw 30 in a second opposite direction and threaded follower 50 carries first end 66 of fulcrum arm 34 along screw 30 opposite the direction of arrow A to lower leg 32. Leg 32 is lowered until pad 60 contacts the bottom of the body of water. Operated in concert with a plurality of lifts 24, as shown in
Pad 60 is pivotally connected to pad pivot tube 62 by a pair of U-shaped pad brackets 64 sized to fit over pad pivot tube 62. Pad brackets 64 are placed over pad pivot tube 62 adjacent to an inner side of leg members 32A, 32B. Holes 180 of pad brackets 64 align with corresponding holes 182 provided in pad 60 to pivotally connect pad 60 to pad brackets 64 with bolts 184 and nuts 186.
In one embodiment, pad 60 is formed of an aluminum plate and may include one or more support braces 188 welded to a bottom of pad 60. Support braces 188 shown in
In one embodiment, the leading and trailing faces of slider block 78 are provided with a magnet 208. As previously discussed, as threaded follower 50 travels along screw 30 toward bearing mounting plate 44, leg 32 is raised to a stowed position. When leg 32 reaches the raised, stowed position, magnet 208 on the leading face of slider block 78 is adjacent stop sensor 200. Stop sensor 200 senses the presence of the magnetic field and sends a representative signal via electrical connection 210 to a switch in control box 212, which opens an electrical connection 213 of motor 28 to battery 214. In alternative embodiments, stop sensor 200 may be positioned to correspond with a portion of leg 32 when leg 32 is in a raised, stowed position, with a magnet mounted on the corresponding portion of leg 32.
Likewise, as threaded follower 50 travels in an opposite direction along screw 30, leg 32 is lowered to engage a bottom of the body of water. In one embodiment, plate 204 with stop sensor 202 are located within channel 26 to ensure that leg 32 is not over-rotated and motor 28 is not over-operated. When threaded follower 50 is near plate 204 and magnet 208 on the trailing face of slider block 78 is adjacent stop sensor 202 a signal is transmitted via electrical connection 216 to a switch in control box 212 to open the electrical connection 213 of motor 28 to battery 214. In alternative embodiments, magnet 208 may be positioned on head 94 of drive screw 82 with corresponding stop sensor 202 positioned on plate 204 accordingly.
The remaining lifts 24 of lift system 10 are similarly electrically configured to control box 212. Control box 212 also receives inputs from a user and synchronizes operation of motors 28 of each lift 24 to raise and lower pontoon boat 12 relative to the surface of the water. Additionally, each motor 28 can be individually operated such as for leveling pontoon boat 12.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.
This application is a continuation of application Ser. No. 11/130,458 filed on May 16, 2005, which is a divisional of application Ser. No. 10/792,942 filed on Mar. 4, 2004.
Number | Date | Country | |
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Parent | 10792942 | Mar 2004 | US |
Child | 11130458 | May 2005 | US |
Number | Date | Country | |
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Parent | 11130458 | May 2005 | US |
Child | 11216691 | Aug 2005 | US |