(19)Fresh off Patent
(45) Week of Oct 5, 2026 No. 5 3,852 lapsed 197 picks
Manufacturing & industrial · lapsed Aug 28, 2026

Hydraulic-actuated boat lift with pivoting dual frames

A watercraft lift that uses two pivoting movable frames and a piston-and-cylinder actuator arranged with the cylinder and rod attached to opposite movable-frame attachment points. Extending or retracting the rod moves the support member (bunks or cradle) between lowered and raised positions by changing the relative heights of the two attachment points. Intended users are marinas, dock builders and boat owners who mount lifts to fixed shore or piling frames.

Sheet 1 of the patent drawingsSheet 2 of the patent drawingsSheet 3 of the patent drawings

(57) What the patent covered

The main independent claim covers a fixed frame carrying two movable frames that each pivot on parallel lower axes, with the support member pivoting on upper axes, and with at least one actuator assembly whose cylinder is pivotably connected at one movable-frame attachment point and whose rod is pivotably connected at the other movable-frame attachment point; when the rod extends the support member is lowered and when it retracts the support is raised, and as the support moves the first attachment point passes below/above the plane defined by the lower axes.

The distinctive part: The actuator is a single cylinder/rod pair whose ends are pivoted to two separate movable-frame attachment points so that extending/retracting the rod changes the relative vertical position of those attachments and lifts the support via the linked frames.

Novelty 3/5. This is a clever kinematic arrangement rather than a wholly new kind of boat lift; boat lifts with pivoting arms and hydraulic cylinders were common, but this patent emphasizes the specific geometry of two movable frames and opposite pivot connections of cylinder and rod.

Making it

Welded steel fixed frame and movable arms from tube and plate, machined pivot bosses and welded brackets, off-the-shelf hydraulic cylinders assembled and pinned, bunk assemblies (timber or extruded aluminum with foam/rubber covering) bolted on; final assembly with pins, hydraulic fittings and testing.

Materials: steel tube frame (structural steel), stamped or welded steel brackets and arms, hydraulic cylinder with steel rod and seals, rubber or foam bunk covers (support members)

Manufacturability 4/5. Several welded and machined steel parts plus a hydraulic cylinder and pins; needs common fab shop tooling and moderate assembly but no exotic processes.

Is anyone buying?

Comparable products are on sale; this exact design wasn't found. Listings indicate hydraulic actuators driving two-frame lift configurations; multiple US retailers list two-cylinder hydraulic systems for PWC and boat lifts, with remote controls and cantilever/piling-mount variants; many listings do not publish exact prices online.

This demand check was run with a web search in the week of Oct 5, 2026. Listings change often, so treat it as a starting point for your own research.

Who buys it: marinas, dock contractors, boat owners with shore mounts

Sourcing

Factories already list this kind of product on supplier marketplaces. Listings exist for hydraulic boat lift frames/arms with pivoting features or similar assemblies; none publicly display explicit unit prices or MOQs. OEM/private-label customization is common in this sector (especially via Alibaba-type listings).

Supplier prices come from public listings found with a web search and are usually quoted before customization, shipping and duties, so use them to judge whether a product is worth a quote request.

Before you make it

We didn't find any related continuation or divisional patents still in force, although that doesn't rule out design patents, trademarks or unrelated patents covering the same product.

Practical issues include corrosion protection for steel/hydraulics in a marine environment and ensuring pivot and cylinder sizing for boat weight; the patent focuses on kinematics and may be narrow in geometric detail.

Owners occasionally revive lapsed patents (about 1.5% are), and this page is a research lead rather than legal advice, so get a freedom-to-operate opinion before you manufacture anything.

Claim 1, as granted

1. A lift system for watercraft comprising: a fixed frame; at least one support member; a first movable frame defining a first attachment point, where the first movable frame is attached to the fixed frame for rotation about a first lower axis, and the at least one support member for rotation about a first upper axis; a second movable frame defining a second attachment point, where the second movable frame is attached to the fixed frame for rotation about a second lower axis, and the at least one support member for rotation about a second upper axis; and at least one actuator assembly comprising a cylinder and a rod arranged in retracted and extended positions relative to the cylinder, where the cylinder is pivotably connected to the first attachment point, and the rod is pivotably connected to the second attachment point; wherein when the rod is arranged in the extended position relative to the cylinder, the at least one support member is in a lowered position relative to the fixed frame; when the rod is arranged in the retracted position relative to the cylinder, the at least one support member is in a raised position relative to the fixed frame; as the at least one support member moves between the lowered and raised positions, the first attachment point is below the second attachment point; as the at least one support member moves from the raised position to the lowered position, the first movable frame rotates about the first lower axis towards the second movable frame and the second movable frame rotates about the second lower axis away from the first movable frame; and as the at least one support member moves from the lowered position to the raised position, the first movable frame rotates about the first lower axis away from the second movable frame and the second movable frame rotates about the second lower axis towards the first movable frame.