A wheel kit for use with a boat lift includes an upper member attachable to the boat lift, and a lower member slidably disposable within the upper member. The lower member contains an axle and a wheel assembly. A braking member includes a base plate with a first side and an opposing second side, a wedge portion outwardly extending from an upper end of the first side, and a tab outwardly extending from a lower end of the first side of the base plate. The braking member slidably disposes upon the axle via an aperture contained within the base plate. When positioning the lower member into the upper member to retract the wheel assembly, the wedge portion of the braking member contacts a closed terminal end of a slot contain within the upper member, outwardly urging the braking member against the wheel assembly to prevent rotation of the wheel assembly.

A wheel kit for use with a boat lift includes an upper member attachable to the boat lift, and a lower member slidably disposable within the upper member. The lower member contains an axle and a wheel assembly. A braking member includes a base plate with a first side and an opposing second side, a wedge portion outwardly extending from an upper end of the first side, and a tab outwardly extending from a lower end of the first side of the base plate. The braking member slidably disposes upon the axle via an aperture contained within the base plate. When positioning the lower member into the upper member to retract the wheel assembly, the wedge portion of the braking member contacts a closed terminal end of a slot contain within the upper member, outwardly urging the braking member against the wheel assembly to prevent rotation of the wheel assembly.

A boat lift controller may include a digital switch, a power-isolation relay, and a motor-direction-select relay, together which control a motor. The digital switch may provide power to the power-isolation relay. The power-isolation relay may provide power to the motor-direction-select relay and to the motor. The motor-direction-select relay may control the direction in which the shaft of the motor turns.

A boat lift controller may include a digital switch, a power-isolation relay, and a motor-direction-select relay, together which control a motor. The digital switch may provide power to the power-isolation relay. The power-isolation relay may provide power to the motor-direction-select relay and to the motor. The motor-direction-select relay may control the direction in which the shaft of the motor turns.

A boat lift that may have a first worm screw operably connected to the drive shaft defining an axis of rotation aligned with the drive shaft and operably contacting a first worm gear, the first worm screw and the first worm gear defines a first lifting stage. The boat lift may also have a second worm screw operably connected to the first worm gear and operably contacts a second worm gear, the second worm screw and the second worm gear defines a second lifting stage. The boat lift may have a tapered roller bearing assembly that operably engages the second worm screw, the tapered roller bearing assembly has a first tapered roller bearing secured at a first location proximate a first end of the second worm screw and a second tapered roller bearing secured at a second location proximate a second opposing end of the second worm screw.

A boat lift that may have a first worm screw operably connected to the drive shaft defining an axis of rotation aligned with the drive shaft and operably contacting a first worm gear, the first worm screw and the first worm gear defines a first lifting stage. The boat lift may also have a second worm screw operably connected to the first worm gear and operably contacts a second worm gear, the second worm screw and the second worm gear defines a second lifting stage. The boat lift may have a tapered roller bearing assembly that operably engages the second worm screw, the tapered roller bearing assembly has a first tapered roller bearing secured at a first location proximate a first end of the second worm screw and a second tapered roller bearing secured at a second location proximate a second opposing end of the second worm screw.

A catamaran lifting apparatus is disclosed for lifting objects in a marine environment. The apparatus includes first and second vessels that are spaced apart during use. A first frame spans between the vessels. A second frame spans between the vessels. The frames are spaced apart and connected to the vessels in a configuration that spaces the vessels apart. The first frame connects to the first vessel with a universal joint and to the second vessel with a hinged connection. The second frame connects to the second vessel with a universal joint and to the first vessel with a hinged or pinned connection. Each of the frames extends upwardly in an inverted u-shape, providing a space under the frame and in between the barges that enables a marine vessel to he positioned in between the barges and under the frames.

A catamaran lifting apparatus is disclosed for lifting objects in a marine environment. The apparatus includes first and second vessels that are spaced apart during use. A first frame spans between the vessels. A second frame spans between the vessels. The frames are spaced apart and connected to the vessels in a configuration that spaces the vessels apart. The first frame connects to the first vessel with a universal joint and to the second vessel with a hinged connection. The second frame connects to the second vessel with a universal joint and to the first vessel with a hinged or pinned connection. Each of the frames extends upwardly in an inverted u-shape, providing a space under the frame and in between the barges that enables a marine vessel to he positioned in between the barges and under the frames.

A lifting device for lifting various vessels includes a two-speed boat lift transmission enables a boat lift to operate at two speeds, i.e. a high speed when the lift is empty or when lowering a boat, and a low speed when lifting the boat. The worm gear drive acts as a speed reducer and it provides locking, so the boat lift cannot back drive. The novel idea of incorporating a harmonic drive differential transmission into the gearbox assembly allows the use of two inputs and ratios, enabling both high speed and low speed operation.

A lifting device for lifting various vessels includes a two-speed boat lift transmission enables a boat lift to operate at two speeds, i.e. a high speed when the lift is empty or when lowering a boat, and a low speed when lifting the boat. The worm gear drive acts as a speed reducer and it provides locking, so the boat lift cannot back drive. The novel idea of incorporating a harmonic drive differential transmission into the gearbox assembly allows the use of two inputs and ratios, enabling both high speed and low speed operation.