FAILSAFE WATERCRAFT LIFT WITH CONVERTIBLE LEVELING SYSTEM
A watercraft lift for raising and lowering a watercraft in water, including a buoyant pontoon, a lifting cradle and at least one pivot arm. The lifting cradle includes at least one air tank and a support bunk configured to receive and support the watercraft. The air tank has an internal chamber configured to receive and release pressurized air. The internal chamber has sufficient internal volume that when sufficient pressurized air is received therein the air tank has sufficient buoyancy to lift the lifting cradle to a raised position with the watercraft out of the water when positioned on the support bunk and that when sufficient pressurized air is released from the internal chamber the air tank loses sufficient buoyancy to sink the lifting cradle to a lowered position sufficiently submerged to receive and deploy the watercraft. The pivot arm is pivotally connected to the pontoon and pivotally connected to the lifting cradle to guide movement of the lifting cradle between the lowered position and the raised position.
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The invention generally relates to an apparatus and method for lifting watercraft out of the water.
DESCRIPTION OF THE RELATED ARTThe use of watercraft lifting devices is well known. Out-of-water storage prevents damage resulting from boat contact with docks, other craft or floating debris. It reduces the possibility of the boat breaking free from its moorage and floating adrift or running aground. Out-of-water storage also lessens boat damage associated with long-term exposure to water and water-based pollutants and the attachment of barnacles or other marine growth to the boat's hull. Once a boat is lifted it can be maintained in its position for extended periods of time, relieving the user of maintenance concerns. In certain situations where the water fluctuation is high, water depth is too deep, or permanent mounting is undesired, floating watercraft lifting devices are used. A number of floating lift designs are currently known that provide this basic function.
U.S. Pat. No. 5,002,000 to Rutter uses air filled pontoons as a lifting device combined with a complicated array of air inlet and outlet valves to control lateral stability while lifting. With this device the rear portion of the pontoons are lowered more than the forward portion of the pontoons to allow ingress and egress of the boat. This device, however, is limited in that the watercraft will not be raised or lowered in a horizontal position which is undesirable to many users.
U.S. Pat. No. 5,860,379 to Moody comprises of an inflatable fabric air chamber as the lifting device. While this device raises the boat out of the water, it has many disadvantages including a complicated rope tying configuration for stabilizing, non-horizontal lifting by raising the bow of the watercraft before the stern, and incompatibility with all boats by only fitting boats with outboard and inboard/outboard motors.
U.S. Pat. No. 6,848,380 to Sainz is a floating watercraft lift that addresses the fore and aft stability issues and non-horizontal lifting with the boatlifts described in Moody and Rutter by using air chambers with an arcuate longitudinal top surface and a base side that is flat. While addressing these stability issues, the lift suffers from a number of disadvantages including the lack of a means for keeping the lift stable if air pressure is lost in one or all pontoon chambers, the ability to fit in a narrow boat slip, and the lack of reserve buoyancy to keep the device from sinking if all air pressure is lost.
Two known devices, one from Hydrohoist International, Inc. and the other from Shoremaster, address the fore and aft stability and non-horizontal lifting described in Moody and Rutter in another fashion. Both devices are air displacement watercraft lifts using stabilizing brackets fixed to a dock or slip to maintain horizontal lifting of the watercraft. These fixed stabilizing brackets are undesirable for marina operations and limit the ease of portability for these lifts. A similar method for stabilizing a boat lift is described in U.S. Pat. No. 4,750,444 to Lemvig, wherein the lift is comprised of a platform with a deck and lifting skirt and link arms connecting the platform to a quay. Air is supplied to the lifting skirt to raise a watercraft while the link arms attached to the quay stabilize the platform. Similar to the Hydrohoist and Shoremaster devices, the device of Lemvig requires link arms fixed to a quay to stabilize the lift limiting the portability of the lift.
Hydrohoist International, Inc. and Airberth address portability issues with free floating side tie lifts. These lifts use air tanks rigidly attached to side floatation to control lifting and stability. While allowing for portability and side tie capabilities, these lifts do not raise the watercraft in a horizontal position and have similar disadvantages to Rutter and Moody.
In addition to the above stated short comings, the floating watercraft lifts of Rutter, Moody, Sainz, Hydrohoist, Shoremaster and Air Berth may inadvertently lower the watercraft into the water if air pressure is not maintained in one or all air chambers. In this case the watercraft will become susceptible to the damaging elements described above.
Another difficulty facing floating watercraft lift manufacturers is the multitude of mounting scenarios. To meet the lift mounting requirements, the manufacturers offer different lifts for slip, side-tie and forward mounting applications. By offering three different lifts the manufacturer and dealer must increase inventory levels and warehouse storage space.
Accordingly, there is a need in the art for a floating watercraft lift that addresses all of the following issues of horizontal lifting of the watercraft with a desirable stabilizing feature, compatibility with all boat drive configurations, stability if air pressure is lost in one or all air chambers, the ability to fit in narrow boat slips, portability for ease of installation and removal, damage tolerance to keep the watercraft out of the water if one or all of the air chambers lose air pressure, and convertibility to most floating watercraft lift mounting scenarios.
SUMMARY OF THE INVENTIONA watercraft lift for raising and lowering a watercraft in water. The watercraft lift includes a buoyant pontoon, a lifting cradle and at least one pivot arm. The lifting cradle includes at least one air tank and a support bunk configured to receive and support the watercraft. The air tank has an internal chamber configured to receive and release pressurized air. The internal chamber has sufficient internal volume that when sufficient pressurized air is received therein the air tank has sufficient buoyancy to lift the lifting cradle to a raised position with the watercraft out of the water when positioned on the support bunk and that when sufficient pressurized air is released from the internal chamber the air tank loses sufficient buoyancy to sink the lifting cradle to a lowered position sufficiently submerged to receive and deploy the watercraft. The pivot arm is pivotally connected to the pontoon and pivotally connected to the lifting cradle to guide movement of the lifting cradle between the lowered position and the raised position.
In one embodiment the pontoon includes a buoyant port pontoon portion and a buoyant starboard pontoon portion. The port and starboard pontoon portions are spaced apart sufficient to receive the watercraft therebetween.
The watercraft lift may further include ballast removably attached to the port pontoon portion and ballast removably attached to the starboard pontoon portion in amounts sufficient to prevent the watercraft lift from rolling when the watercraft is positioned on the support bunk with the watercraft lift in the raised position when all pressurized air is released from the internal chamber the air tank. The port and starboard pontoon portions are made of a first material and the ballast is made of a second material, the first material being different than the second material.
The pontoon includes a buoyant port pontoon portion having an end portion and a buoyant starboard pontoon portion having an end portion. The port and starboard pontoon portions are spaced apart sufficient to receive the watercraft therebetween. The pontoon further includes a buoyant connection pontoon portion having the end portions of the port and starboard pontoon portions attached thereto. The combined buoyancy of the port pontoon portion, the starboard pontoon portion and the connection pontoon portion is sufficient hold the watercraft out of the water when the watercraft is positioned on the support bunk with the watercraft lift in the raised position when all pressurized air is released from the internal chamber the air tank.
The port pontoon portion, the starboard pontoon portion and the connection pontoon portion have upper surfaces arranged to provide a floating dock surface for access to the watercraft from three sides thereof when positioned on the support bunk.
The connection pontoon portion has buoyant port and starboard connection pontoon portions, with the end portion of the port pontoon portion attached to the port connection pontoon portion and the end portion of the starboard pontoon portion attached to the starboard connection pontoon portion. The port connection pontoon portion and the starboard connection pontoon portion are removably attached together.
The watercraft lift may further include a lock operable to lock the pivot arm relative to the pontoon when the lifting cradle is in the raised position to prevent downward movement of the pivot arm and thereby movement of the lifting cradle to the lowered position. The lock includes a selectively rotatable upright member having an engagement member attached thereto, the rotatable member being rotatable between a locked position and an unlocked position. In the locked position the engagement member is positioned in locking engagement with the pivot arm to prevent downward movement of the pivot arm and thereby movement of the lifting cradle to the lowered position. In the unlocked position the engagement member is positioned out of locking engagement with the pivot arm to allow downward movement of the pivot arm and thereby movement of the lifting cradle to the lowered position. The lock may include a security member which when engaged prevents rotation of the rotatable member out of the locked position.
Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, which are schematic, and not to scale, wherein:
This section illustrates aspects of the invention, and points out certain preferred embodiments of these aspects. This section is not intended to be exhaustive, but rather to inform and teach the person of skill in the art who will come to appreciate more fully other aspects, equivalents, and possibilities presented by invention, and hence the scope of the invention is set forth in the claims, which alone limit its scope.
Several embodiments of the invention are set forth in the following description:
An isometric view of a watercraft lift 10 in a fully lowered position is shown in
Again referring to
As shown in
The air tanks 40 each include a longitudinally extending, laterally outward projecting lower portion 40A. As best seen in
The side floats 62 and the forward floats 61 are constructed of a sealed rotationally molded plastic shell with a foam filled or an air filled inner core for buoyancy. The buoyancy is selected to be sufficient to keep the watercraft 111 supported high enough above the water and in sufficient frictional contact with the lifting bunks 51 to keep the watercraft from floating off and away from the lifting cradle 50 when the lifting cradle is in the locked raised position even if all air pressure in the air tanks 40 is lost and the air tanks provide no buoyancy. The forward floats 61 are shaped on an inward side to accept and position the bow of the watercraft 111 must like a boat slip, and are designed to be used as mirrored parts as shown in
The port and starboard floating pontoons 60 are attached together at a connection location 69 with a mechanical connection 68 which connects together the front floats 61 of the two floating pontoons. The floating pontoons 60 can be split at the connection location 69 and a spacer float (not shown) can be added therebetween to increase the distance between the side floats 62 of the floating pontoons to accept a boat with a wider beam.
In
The adjustment brackets 49 (best seen if
A lock mechanism 100 is shown in
When engagement lever 104 is rotated along path E to an unlocked position C, the engagement foot 102 rotates to a position where it will not engage swing arm 70 and hence not limit downward rotation of the swing arm toward the lowered position shown in
When the engagement lever 104 is rotated into the locked position D, the lock mechanism 100 prevents accidental or unintended lowering of the watercraft 111 into the water. Even should air pressure be released from the air tanks 40, the locking mechanism will prevent lowering of the lifting cradle 50. When the engagement lever 104 is rotated into the locked position D, the engagement lever 104 may be padlocked to the lock plate 103 or in alternative embodiments otherwise locked to prevent rotation of the lock shaft 101 and hence rotation of the engagement foot 102 from under the swing arm 70. This provides protection against theft of the watercraft 111 when on the lifting cradle 50 in the raised position since without being able to rotate the engagement lever to the unlocked position C, the lifting cradle cannot be lowered to place the watercraft in the water, thus preventing unauthorized removal of the watercraft from the watercraft lift 10.
The floating pontoons 60 can be tied or attached to a dock, sea wall or quay at tie points 66. The watercraft lift 10 is shown in
The watercraft lift 10 is shown in
The watercraft lift 10 is shown in
The watercraft lift 10 is shown in
The watercraft lift 10 is shown in
A plurality of the watercraft lifts 10 are shown in
The watercraft lift 10 is shown in
The watercraft lift 10 is shown in
It will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without departing from the spirit or scope of the invention.
Claims
1. A watercraft lift for raising and lowering a watercraft in water, comprising:
- a buoyant pontoon;
- a lifting cradle including at least one air tank and a support bunk configured to receive and support the watercraft, the air tank having an internal chamber configured to receive and release pressurized air, the internal chamber having sufficient internal volume that when sufficient pressurized air is received therein the air tank has sufficient buoyancy to lift the lifting cradle to a raised position with the watercraft out of the water when positioned on the support bunk and that when sufficient pressurized air is released from the internal chamber the air tank loses sufficient buoyancy to sink the lifting cradle to a lowered position sufficiently submerged to receive and deploy the watercraft; and
- at least one pivot arm pivotally connected to the pontoon and pivotally connected to the lifting cradle to guide movement of the lifting cradle between the lowered position and the raised position.
2. The watercraft lift of claim 1 wherein the pontoon includes a buoyant port pontoon portion and a buoyant starboard pontoon portion, the port and starboard pontoon portions being spaced apart sufficient to receive the watercraft therebetween.
3. The watercraft lift of claim 2 further including ballast positioned at the port pontoon portion and ballast positioned at the starboard pontoon portion in amounts sufficient to prevent the watercraft lift from rolling when the watercraft is positioned on the support bunk with the watercraft lift in the raised position when all pressurized air is released from the internal chamber the air tank.
4. The watercraft lift of claim 3 wherein the ballast is removably attached to the port pontoon portion and the ballast is removably attached to the starboard pontoon portion.
5. The watercraft lift of claim 3 wherein the port and starboard pontoon portions are made of a first material and the ballast is made of a second material, the first material being different than the second material.
6. The watercraft lift of claim 1 wherein the pontoon includes a buoyant port pontoon portion having an end portion and a buoyant starboard pontoon portion having an end portion, the port and starboard pontoon portions being spaced apart sufficient to receive the watercraft therebetween, and further includes a buoyant connection pontoon portion having the end portions of the port and starboard pontoon portions attached thereto, the combined buoyancy of the port pontoon portion, the starboard pontoon portion and the connection pontoon portion being sufficient the support bunk in sufficient contact with the watercraft to prevent the watercraft from floating off of the support bunk when the watercraft is positioned on the support bunk with the watercraft lift in the raised position when all pressurized air is released from the internal chamber the air tank.
7. The watercraft lift of claim 1 wherein the pontoon includes a buoyant port pontoon portion having an end portion and a buoyant starboard pontoon portion having an end portion, the port and starboard pontoon portions being spaced apart sufficient to receive the watercraft therebetween, and further includes a buoyant connection pontoon portion having the end portions of the port and starboard pontoon portions attached thereto, the port pontoon portion, the starboard pontoon portion and the connection pontoon portion having upper surfaces arranged to provide a floating dock surface for access to the watercraft from three sides thereof when positioned on the support bunk.
8. The watercraft lift of claim 1 wherein the pontoon includes a buoyant port pontoon portion having an end portion and a buoyant starboard pontoon portion having an end portion, the port and starboard pontoon portions being spaced apart sufficient to receive the watercraft therebetween, and further includes buoyant port and starboard connection pontoon portions, the end portion of the port pontoon portion being attached to the port connection pontoon portion and the end portion of the starboard pontoon portion being attached to the starboard connection pontoon portion, and the port connection pontoon portion and the starboard connection pontoon portion being removably attached together.
9. The watercraft lift of claim 1 further including a lock operable to lock the pivot arm relative to the pontoon when the lifting cradle is in the raised position to prevent downward movement of the pivot arm and thereby movement of the lifting cradle to the lowered position.
10. The watercraft lift of claim 9 wherein the lock includes a selectively rotatable upright member having an engagement member attached thereto, the rotatable member being rotatable between a locked position and an unlocked position, in the locked position the engagement member being positioned in locking engagement with the pivot arm to prevent downward movement of the pivot arm and thereby movement of the lifting cradle to the lowered position, and in the unlocked position the engagement member being positioned out of locking engagement with the pivot arm to allow downward movement of the pivot arm and thereby movement of the lifting cradle to the lowered position.
11. The watercraft lift of claim 10 wherein the lock includes a security member which when engaged prevents rotation of the rotatable member out of the locked position.
12. The watercraft lift of claim 1 wherein the pivot arm has an upper end portion pivotally connected to the pontoon and a lower end portion pivotally connected to the air tank of the lifting cradle using a laterally extending member, the lower end portion of the pivot arm being connected to an end portion of the member to provide a pivotal connection between the lower end portion of the pivot arm and the air tank.
13. The watercraft lift of claim 1 wherein the air tank has a longitudinally extending integrally molded structural rib projecting upward, the member extending laterally through the structural rib.
14. The watercraft lift of claim 1 wherein the at least one pivot arm includes first and second spaced apart port pivot arms, each having an upper end portion pivotally connected to the pontoon and a lower end portion pivotally connected to the lifting cradle, and wherein the air tank has a longitudinally extending integrally molded structural rib projecting upward and the lower end portions of the first and second pivot arms are pivotally connected to the structural rib.
15. The watercraft lift of claim 14 wherein the support bunk is attached to the air tank in a manner to provide longitudinal rigidity to the air tank.
16. The watercraft lift of claim 1 wherein the air tank has a laterally projecting portion extending outward to under the pontoon to engage the pontoon upon the lifting cradle reaching the raised position.
17. A watercraft lift for raising and lowering a watercraft in water, comprising:
- a buoyant pontoon having a buoyant port pontoon portion with an end portion, a buoyant starboard pontoon portion with an end portion, and a buoyant connection pontoon portion with the end portions of the port and starboard pontoon portions attached thereto, the port and starboard pontoon portions being spaced apart sufficient to receive the watercraft therebetween;
- a lifting cradle including an air tank assembly and a support bunk configured to receive and support the watercraft, the air tank assembly having at least one internal chamber configured to receive and release pressurized air, the internal chamber having sufficient internal volume that when sufficient pressurized air is received therein the air tank assembly has sufficient buoyancy to lift the lifting cradle to a raised position with the watercraft out of the water when positioned on the support bunk and that when sufficient pressurized air is released from the internal chamber the air tank assembly loses sufficient buoyancy to sink the lifting cradle to a lowered position sufficiently submerged to receive and deploy the watercraft; and
- at least one port pivot arm pivotally connected to the port pontoon portion and pivotally connected to the lifting cradle, and at least one starboard pivot arm pivotally connected to the starboard pontoon portion and pivotally connected to the lifting cradle, the port and starboard pivot arms configured to guide movement of the lifting cradle between the lowered position and the raised position.
18. The watercraft lift of claim 17 wherein the port and starboard pivot arms are pivotally connected to the lifting cradle using a member extending between a port side of the lifting cradle and a starboard side of the lifting cradle, the port pivot arm being connected to a port end of the member and the starboard pivot arm being connected to a starboard end of the member.
19. The watercraft lift of claim 18 wherein the member is a torsion bar.
20. The watercraft lift of claim 17 wherein the pontoon includes a buoyant port pontoon portion having an end portion and a buoyant starboard pontoon portion having an end portion, the port and starboard pontoon portions being spaced apart sufficient to receive the watercraft therebetween, and further includes a buoyant connection pontoon portion having the end portions of the port and starboard pontoon portions attached thereto, the combined buoyancy of the port pontoon portion, the starboard pontoon portion and the connection pontoon portion being sufficient the support bunk in sufficient contact with the watercraft to prevent the watercraft from floating off of the support bunk when the watercraft is positioned on the support bunk with the watercraft lift in the raised position when all pressurized air is released from the internal chamber the air tank assembly.
21. The watercraft lift of claim 17 further including a first lock operable to lock the port pivot arm relative to the port pontoon portion when the lifting cradle is in the raised position to prevent downward movement of the port pivot arm and thereby movement of the lifting cradle to the lowered position, and a second lock operable to lock the starboard pivot arm relative to the starboard pontoon portion when the lifting cradle is in the raised position to prevent downward movement of the starboard pivot arm and thereby movement of the lifting cradle to the lowered position.
22. The watercraft lift of claim 21 wherein the first lock includes a selectively rotatable first rotatable upright member having a first engagement member attached thereto, the first rotatable member being rotatable supported by the port pontoon portion and rotatable between a locked position and an unlocked position, in the locked position the first engagement member being positioned in locking engagement with the port pivot arm to prevent downward movement of the port pivot arm and thereby movement of the lifting cradle to the lowered position, and in the unlocked position the engagement member being positioned out of locking engagement with the port pivot arm to allow downward movement of the port pivot arm and thereby movement of the lifting cradle to the lowered position, and a selectively rotatable second rotatable upright member having a second engagement member attached thereto, the second rotatable member being rotatable supported by the starboard pontoon portion and rotatable between a locked position and an unlocked position, in the locked position the second engagement member being positioned in locking engagement with the starboard pivot arm to prevent downward movement of the starboard pivot arm and thereby movement of the lifting cradle to the lowered position, and in the unlocked position the engagement member being positioned out of locking engagement with the starboard pivot arm to allow downward movement of the starboard pivot arm and thereby movement of the lifting cradle to the lowered position.
23. The watercraft lift of claim 22 wherein the first lock includes a first security member which when engaged prevents rotation of the first rotatable member out of the locked position, and the second lock includes a second security member when engaged prevents rotation of the second rotatable member out of the locked position.
24. The watercraft lift of claim 17 wherein the port and starboard pivot arms each have an upper end portion and a lower end portion, the upper end portion of the port pivot arm being pivotally connected to the port pontoon portion and the lower end portion of the port pivot arm being pivotally connected to the air tank assembly of the lifting cradle, and the upper end portion of the starboard pivot arm being pivotally connected to the starboard pontoon portion and the lower end portion of the starboard pivot arm being pivotally connected to the air tank assembly of the lifting cradle.
25. The watercraft lift of claim 24 further including a member extending between a port side of the air tank assembly and a starboard side of the air tank assembly, the lower end portion of the port pivot arm being connected to a port end of the member and the lower end portion of the starboard pivot arm being connected to a starboard end of the member.
26. The watercraft lift of claim 17 wherein the air tank assembly has a longitudinally extending integrally molded structural rib projecting upward, the member extending laterally through the structural rib.
27. The watercraft lift of claim 17 wherein the at least one port pivot arm includes first and second spaced apart port pivot arms, each having an upper end portion pivotally connected to the port pontoon portion and a lower end portion pivotally connected to the lifting cradle, and the at least one starboard pivot arm includes first and second spaced apart starboard pivot arms, each having an upper end portion pivotally connected to the starboard pontoon portion and a lower end portion pivotally connected to the lifting cradle, and wherein the air tank assembly has a longitudinally extending integrally molded structural rib projecting upward and the lower end portions of the first and second port and starboard pivot arms are pivotally connected to the structural rib.
28. The watercraft lift of claim 27 wherein the support bunk is attached to the air tank assembly in a manner to provide longitudinal rigidity to the air tank assembly.
29. The watercraft lift of claim 17 wherein the air tank has a laterally projecting portion extending outward to under the pontoon to engage the pontoon upon the lifting cradle reaching the raised position.
30. A watercraft lift for raising and lowering a watercraft in water, comprising:
- a buoyant pontoon having a buoyant port pontoon portion with an end portion, a buoyant starboard pontoon portion with an end portion, and a buoyant connection pontoon portion with the end portions of the port and starboard pontoon portions attached thereto, the port and starboard pontoon portions being spaced apart sufficient to receive the watercraft therebetween;
- a lifting cradle with support bunks attached thereto and including a port internal chamber configured to receive and release pressurized air, and a starboard internal chamber configured to receive and release pressurized air, the support bunks being configured to receive and support the watercraft, the combined port and starboard internal chambers having sufficient internal volume that when sufficient pressurized air is received therein the lifting cradle has sufficient buoyancy to lift the lifting cradle to a raised position with the watercraft out of the water when positioned on the support bunks and that when sufficient pressurized air is released from the port and starboard internal chambers the lifting cradle loses sufficient buoyancy to sink the lifting cradle to a lowered position sufficiently submerged to receive and deploy the watercraft; and
- at least one port pivot arm having an upper end portion pivotally connected to the port pontoon portion and a lower end portion pivotally connected to the lifting cradle, and at least one starboard pivot arm having an upper end portion pivotally connected to the starboard pontoon portion and a lower end portion pivotally connected to the lifting cradle, the port and starboard pivot arms configured to guide movement of the lifting cradle between the lowered position and the raised position.
31. The watercraft lift of claim 30 wherein a lifting cradle includes at least one port air tank defining the port internal chamber and at least one starboard air tank defining the starboard internal chamber.
32. The watercraft lift of claim 31 further including a hydrodynamic brake extending between the port and starboard air tanks to create additional resistance against movement of the lifting cradle.
33. The watercraft lift of claim 31 wherein the lower end portion of the port pivot arm is pivotally connected to the port air tank of the lifting cradle, and the lower end portion of the starboard pivot arm is pivotally connected to the starboard air tank of the lifting cradle.
34. The watercraft lift of claim 33 wherein the lower end portions of the port and starboard pivot arms are pivotally connected to the port and starboard air tanks of the lifting cradle using a member extending between a port side of the port air tank and a starboard side of the starboard air tank, the lower end portion of the port pivot arm being connected to a port end of the member and the lower end portion of the starboard pivot arm being connected to a starboard end of the member.
35. The watercraft lift of claim 34 wherein the member is a torsion bar extending through an aperture in the port and starboard air tanks.
36. The watercraft lift of claim 31 wherein the port air tank has a laterally projecting portion extending outward to under the port pontoon portion to engage the port pontoon portion upon the lifting cradle reaching the raised position, and the starboard air tank has a laterally projecting portion extending outward to under the starboard pontoon portion to engage the starboard pontoon portion upon the lifting cradle reaching the raised position.
37. The watercraft lift of claim 30 further including a port relief port communicating with the port internal chamber and a starboard relief port communicating with the starboard internal chamber, the port and starboard relief ports being arranged to permit the release of pressurized air in one of the port internal chamber and the starboard internal chamber based on which is least submerged in the water.
38. The watercraft lift of claim 37 wherein a lifting cradle includes at least one port air tank defining the port internal chamber and at least one starboard air tank defining the starboard internal chamber, and the port relief port is positioned at a port side of the port air tank and the starboard relief port is positioned at a starboard side of the starboard air tank.
39. The watercraft lift of claim 30 further including a hydrodynamic brake extending between the port and starboard air tanks to create additional resistance against movement of the lifting cradle.
40. The watercraft lift of claim 30 for conversion for use with a slip having port and starboard side members, wherein the upper end portion of the port pivot arm is removably connected to the port pontoon portion and pivotally attachable to the port side member of the slip, and the upper end portion of the starboard pivot arm is removably connected to the starboard pontoon portion and pivotally attachable to the starboard side member of the slip.
41. The watercraft lift of claim 30 wherein the port and starboard pontoon portions are each a rotomolded plastic part.
42. A watercraft lift for raising and lowering a watercraft in water, comprising:
- a buoyant pontoon having a buoyant port pontoon portion with an end portion, a buoyant starboard pontoon portion with an end portion, and a buoyant connection pontoon portion with the end portions of the port and starboard pontoon portions attached thereto, the port and starboard pontoon portions being spaced apart sufficient to receive the watercraft therebetween;
- a lifting cradle including a port air tank with a port support bunk attached thereto and having an internal chamber configured to receive and release pressurized air, and a starboard air tank with a starboard support bunk attached thereto and having an internal chamber configured to receive and release pressurized air, the port and starboard support bunks being configured to receive and support the watercraft, the combined internal chambers of the port and starboard air tanks having sufficient internal volume that when sufficient pressurized air is received therein the port and starboard air tanks have sufficient buoyancy to lift the lifting cradle to a raised position with the watercraft out of the water when positioned on the port and starboard support bunks and that when sufficient pressurized air is released from the internal chambers of the port and starboard air tanks the air tanks loses sufficient buoyancy to sink the lifting cradle to a lowered position sufficiently submerged to receive and deploy the watercraft; and
- first and second spaced apart port pivot arms, each having an upper end portion pivotally connected to the port pontoon portion and a lower end portion pivotally connected to the lifting cradle, and first and second spaced apart starboard pivot arms, each having an upper end portion pivotally connected to the starboard pontoon portion and a lower end portion pivotally connected to the lifting cradle, the port and starboard pivot arms configured to guide movement of the lifting cradle between the lowered position and the raised position, the first and second port pivot arms, the port pontoon portion and the lifting cradle being in a 4-bar linkage arrangement and the first and second starboard pivot arms, the starboard pontoon portion and the lifting cradle being in a 4-bar linkage arrangement.
43. The watercraft lift of claim 42 wherein the lower end portions of the first and second port pivot arms are pivotally connected to the port air tank of the lifting cradle, and the lower end portions of the first and second of the starboard pivot arms are pivotally connected to the starboard air tank of the lifting cradle.
44. The watercraft lift of claim 43 wherein the lower end portions of the first port pivot arm and the first starboard pivot arm are pivotally connected to the port and starboard air tanks of the lifting cradle using a first member extending between a port side of the port air tank and a starboard side of the starboard air tank, the lower end portion of the first port pivot arm being connected to a port end of the first member and the lower end portion of the first starboard pivot arm being connected to a starboard end of the first member, and wherein the lower end portions of the second port pivot arm and the second starboard pivot arm are pivotally connected to the port and starboard air tanks of the lifting cradle using a second member extending between a port side of the port air tank and a starboard side of the starboard air tank and spaced apart from the first member, the lower end portion of the second port pivot arm being connected to a port end of the second member and the lower end portion of the second starboard pivot arm being connected to a starboard end of the second member.
45. The watercraft lift of claim 44 wherein the first and second member are a torsion bars, each extending through an aperture in the port and starboard air tanks.
46. The watercraft lift of claim 44 wherein the port and starboard air tanks each have a longitudinally extending integrally molded structural rib projecting upward, the first member extending through the structural rib of the port and starboard air tanks, and the second member extending through the structural rib of the port and starboard air tanks.
47. The watercraft lift of claim 43 wherein the port and starboard air tanks each have a longitudinally extending integrally molded structural rib projecting upward, and the lower end portions of the first and second port pivot arms are pivotally connected to the structural rib of the port air tank and the lower end portions of the first and second starboard pivot arms are pivotally connected to the structural rib of the starboard air tank.
48. The watercraft lift of claim 47 wherein the port support bunk is attached to the port air tank in a manner to provide longitudinal rigidity to the port air tank, and the starboard support bunk is attached to the starboard air tank in a manner to provide longitudinal rigidity to the starboard air tank.
49. The watercraft lift of claim 42 further including a port relief port communicating with the interior chamber of the port air tank and a starboard relief port communicating with the interior chamber of the starboard air tank, the port and starboard relief ports being arranged to permit the release of pressurized air in the interior chamber of the one of the port and starboard air tanks that is least submerged in the water.
50. The watercraft lift of claim 49 wherein the port relief port is positioned at the port side of the port air tank and the starboard relief port is positioned at the starboard side of the starboard air tank.
51. The watercraft lift of claim 42 further including a first lock operable to lock one of the first and second port pivot arms relative to the port pontoon portion when the lifting cradle is in the raised position to prevent downward movement of the one port pivot arm and thereby movement of the lifting cradle to the lowered position, and a second lock operable to lock one of the first and second starboard pivot arms relative to the starboard pontoon portion when the lifting cradle is in the raised position to prevent downward movement of the one starboard pivot arm and thereby movement of the lifting cradle to the lowered position.
52. The watercraft lift of claim 51 wherein the first lock includes a selectively rotatable first rotatable upright member having a first engagement member attached thereto, the first rotatable member being rotatable supported by the port pontoon portion and rotatable between a locked position and an unlocked position, in the locked position the first engagement member being positioned in locking engagement with the one port pivot arm to prevent downward movement of the one port pivot arm and thereby movement of the lifting cradle to the lowered position, and in the unlocked position the engagement member being positioned out of locking engagement with the one port pivot arm to allow downward movement of the one port pivot arm and thereby movement of the lifting cradle to the lowered position, and a selectively rotatable second rotatable upright member having a second engagement member attached thereto, the second rotatable member being rotatable supported by the starboard pontoon portion and rotatable between a locked position and an unlocked position, in the locked position the second engagement member being positioned in locking engagement with the one starboard pivot arm to prevent downward movement of the one starboard pivot arm and thereby movement of the lifting cradle to the lowered position, and in the unlocked position the engagement member being positioned out of locking engagement with the one starboard pivot arm to allow downward movement of the one starboard pivot arm and thereby movement of the lifting cradle to the lowered position.
53. The watercraft lift of claim 52 wherein the first lock includes a first security member which when engaged prevents rotation of the first rotatable member out of the locked position, and the second lock includes a second security member when engaged prevents rotation of the second rotatable member out of the locked position.
54. A watercraft lift for raising and lowering a watercraft in water, attachable to a slip having a port side and a starboard side, the watercraft lift comprising:
- a lifting cradle including a port air tank with a port support bunk attached thereto and having an internal chamber configured to receive and release pressurized air, and a starboard air tank with a starboard support bunk attached thereto and having an internal chamber configured to receive and release pressurized air, the port and starboard support bunks being configured to receive and support the watercraft, the combined internal chambers of the port and starboard air tanks having sufficient internal volume that when sufficient pressurized air is received therein the port and starboard air tanks have sufficient buoyancy to lift the lifting cradle to a raised position with the watercraft out of the water when positioned on the port and starboard support bunks and that when sufficient pressurized air is released from the internal chambers of the port and starboard air tanks the air tanks loses sufficient buoyancy to sink the lifting cradle to a lowered position sufficiently submerged to receive and deploy the watercraft;
- first and second spaced apart port pivot arms, each having an upper end portion pivotally connectable to the port side of the slip and a lower end portion pivotally connected to the lifting cradle, and first and second spaced apart starboard pivot arms, each having an upper end portion pivotally connectable to the starboard side of the slip and a lower end portion pivotally connected to the lifting cradle, the port and starboard pivot arms configured to guide movement of the lifting cradle between the lowered position and the raised position, the first and second port pivot arms, the port side of the slip and the lifting cradle forming a 4-bar linkage arrangement and the first and second starboard pivot arms, the starboard side of the slip and the lifting cradle forming a 4-bar linkage arrangement; and
- a first lock operable to lock one of the first and second port pivot arms relative to the port side of the slip when the lifting cradle is in the raised position to prevent downward movement of the one port pivot arm and thereby movement of the lifting cradle to the lowered position, and a second lock operable to lock one of the first and second starboard pivot arms relative to the starboard side of the slip when the lifting cradle is in the raised position to prevent downward movement of the one starboard pivot arm and thereby movement of the lifting cradle to the lowered position.
55. The watercraft lift of claim 54 wherein the first lock includes a selectively rotatable first rotatable upright member having a first engagement member attached thereto, the first rotatable member being rotatable supported by the port side of the slip and rotatable between a locked position and an unlocked position, in the locked position the first engagement member being positioned in locking engagement with the one port pivot arm to prevent downward movement of the one port pivot arm and thereby movement of the lifting cradle to the lowered position, and in the unlocked position the engagement member being positioned out of locking engagement with the one port pivot arm to allow downward movement of the one port pivot arm and thereby movement of the lifting cradle to the lowered position, and a selectively rotatable second rotatable upright member having a second engagement member attached thereto, the second rotatable member being rotatable supported by the starboard side of the slip and rotatable between a locked position and an unlocked position, in the locked position the second engagement member being positioned in locking engagement with the one starboard pivot arm to prevent downward movement of the one starboard pivot arm and thereby movement of the lifting cradle to the lowered position, and in the unlocked position the engagement member being positioned out of locking engagement with the one starboard pivot arm to allow downward movement of the one starboard pivot arm and thereby movement of the lifting cradle to the lowered position.
56. The watercraft lift of claim 55 wherein the first lock includes a first security member which when engaged prevents rotation of the first rotatable member out of the locked position, and the second lock includes a second security member when engaged prevents rotation of the second rotatable member out of the locked position.
57. A watercraft lift for raising and lowering a watercraft in water, attachable to a slip having a port side and a starboard side, the watercraft lift comprising:
- a lifting cradle including a port air tank with a port support bunk attached thereto and having an internal chamber configured to receive and release pressurized air, and a starboard air tank with a starboard support bunk attached thereto and having an internal chamber configured to receive and release pressurized air, the port and starboard support bunks being configured to receive and support the watercraft, the combined internal chambers of the port and starboard air tanks having sufficient internal volume that when sufficient pressurized air is received therein the port and starboard air tanks have sufficient buoyancy to lift the lifting cradle to a raised position with the watercraft out of the water when positioned on the port and starboard support bunks and that when sufficient pressurized air is released from the internal chambers of the port and starboard air tanks the air tanks loses sufficient buoyancy to sink the lifting cradle to a lowered position sufficiently submerged to receive and deploy the watercraft;
- first and second spaced apart port pivot arms, each having an upper end portion pivotally connectable to the port side of the slip and a lower end portion pivotally connected to the lifting cradle, and first and second spaced apart starboard pivot arms, each having an upper end portion pivotally connectable to the starboard side of the slip and a lower end portion pivotally connected to the lifting cradle, the port and starboard pivot arms configured to guide movement of the lifting cradle between the lowered position and the raised position, the first and second port pivot arms, the port side of the slip and the lifting cradle forming a 4-bar linkage arrangement and the first and second starboard pivot arms, the starboard side of the slip and the lifting cradle forming a 4-bar linkage arrangement; and
- a first member attached to port and starboard air tanks and extending between a port side of the port air tank and a starboard side of the starboard air tank, the lower end portions of the first port pivot arm and the first starboard pivot arm being pivotally connected to the port and starboard air tanks of the lifting cradle using the first member, the lower end portion of the first port pivot arm being connected to a port end of the first member and the lower end portion of the first starboard pivot arm being connected to a starboard end of the first member; and
- a second member attached to port and starboard air tanks and extending between a port side of the port air tank and a starboard side of the starboard air tank and spaced apart from the first member, the lower end portions of the second port pivot arm and the second starboard pivot arm being pivotally connected to the port and starboard air tanks of the lifting cradle using the second member, the lower end portion of the second port pivot arm being connected to a port end of the second member and the lower end portion of the second starboard pivot arm being connected to a starboard end of the second member.
58. The watercraft lift of claim 57 wherein the first and second member are a torsion bars, each extending through an aperture in the port and starboard air tanks.
59. The watercraft lift of claim 57 wherein the port and starboard air tanks each have a longitudinally extending integrally molded structural rib projecting upward, the first member extending through the structural rib of the port and starboard air tanks, and the second member extending through the structural rib of the port and starboard air tanks.
60. The watercraft lift of claim 57 wherein the port support bunk is attached to the port air tank in a manner to provide longitudinal rigidity to the port air tank, and the starboard support bunk is attached to the starboard air tank in a manner to provide longitudinal rigidity to the starboard air tank.
61. A watercraft lift for raising and lowering a watercraft in water, attachable to a slip having a port side and a starboard side, the watercraft lift comprising:
- a lifting cradle including a port air tank with a port support bunk attached thereto and having an internal chamber configured to receive and release pressurized air, and a starboard air tank with a starboard support bunk attached thereto and having an internal chamber configured to receive and release pressurized air, the port and starboard support bunks being configured to receive and support the watercraft, the combined internal chambers of the port and starboard air tanks having sufficient internal volume that when sufficient pressurized air is received therein the port and starboard air tanks have sufficient buoyancy to lift the lifting cradle to a raised position with the watercraft out of the water when positioned on the port and starboard support bunks and that when sufficient pressurized air is released from the internal chambers of the port and starboard air tanks the air tanks loses sufficient buoyancy to sink the lifting cradle to a lowered position sufficiently submerged to receive and deploy the watercraft;
- first and second spaced apart port pivot arms, each having an upper end portion pivotally connectable to the port side of the slip and a lower end portion pivotally connected to the lifting cradle, and first and second spaced apart starboard pivot arms, each having an upper end portion pivotally connectable to the starboard side of the slip and a lower end portion pivotally connected to the lifting cradle, the port and starboard pivot arms configured to guide movement of the lifting cradle between the lowered position and the raised position, the first and second port pivot arms, the port side of the slip and the lifting cradle forming a 4-bar linkage arrangement and the first and second starboard pivot arms, the starboard side of the slip and the lifting cradle forming a 4-bar linkage arrangement; and
- a hydrodynamic brake extending between the port and starboard air tanks to create additional resistance against movement of the lifting cradle.
Type: Application
Filed: Mar 23, 2007
Publication Date: Jan 10, 2008
Applicant: SUNSTREAM CORPORATION (Kent, WA)
Inventors: Kenneth Hey (Mercer Island, WA), Bryce Kloster (Snoqualmie, WA)
Application Number: 11/690,732
International Classification: B63C 3/06 (20060101);