(19)Fresh off Patent
(45) Week of Oct 19, 2026 No. 7 3,667 lapsed 70 listed
Auto, bikes & mobility · lapsed Sep 4, 2026

Trolley wheel with centrifugal magnet arms that induce eddy-current braking

A trolley wheel assembly for zip-lines or coaster-type rides that uses arms with permanent magnets which swing outward under centrifugal force and move relative to adjacent non-ferrous conductive plates to generate eddy currents that oppose wheel rotation and slow the trolley. Intended users include ride operators, adventure-park owners and equipment suppliers for gravity-propelled rider conveyances.

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

(57) What the patent covered

This write-up was generated by AI from the patent's text and may contain mistakes, so check it against the original patent before relying on it.

The main independent claim covers a rotating wheel with one or more arms that deploy from a closed to a deployed position by centrifugal force, permanent magnets mounted on those arms, and an adjacent plate of non‑ferrous conductive material positioned so that relative movement between each magnet and the plate generates eddy currents that oppose wheel rotation; the plate has at least two sections at different distances from the magnet surfaces so braking changes as arms move.

Distinguishing feature: Magnets are mounted on centrifugal arms that change proximity to a multi‑section non‑ferrous conductive plate as the arms deploy, varying eddy‑current braking with wheel speed.

Novelty 4/5. Eddy‑current braking and magnet‑to‑conductive plate brakes were known; the novelty was applying centrifugal deployable magnet arms and multi‑section plate geometry to vary braking with rotation speed.

Manufacturing

Stamped or laser‑cut conductive plate, injection‑molded or stamped arms, bonded/fastened magnets to arms, wheel assembly with standard bearings; assembled with mechanical fastening and press‑fit or bolted hubs.

Materials: Aluminum or copper non‑ferrous conductive plate, Permanent magnets (rare‑earth or ferrite), Stamped steel or molded polymer arms, Steel or aluminum wheel hub.

Manufacturability 4/5. Several simple parts (plate, arms, magnets, wheel) requiring stamping/molding, magnet bonding and standard wheel/bearing assembly; moderate hand or machine assembly.

Market demand

Comparable products are on sale; this exact design was not found. Multiple vendors advertise non-contact eddy-current braking trolleys for zip lines, including both integrated systems and modular braking components; at least one US-based vendor lists a fixed price for a braking trolley kit.

Demand check by web search, week of Oct 12, 2026. Listings change frequently.

Buyers: Zip‑line and adventure park operators; ride equipment suppliers.

Sourcing

Factories list related products that could be adapted. These Made-in-China listings show magnetic braking devices integrated with hoist/trolley hardware (not a dedicated zipline eddy-current trolley). They illustrate related concepts (magnetic braking, trolley integration, OEM/PRIVATE LABEL potential) but do not show a cataloged zipline eddy-current trolley as described. Availability, exact product fit, and customization would require direct supplier confirmation.

Supplier prices are from public listings found by web search, quoted before customization, shipping and duties. Use them to decide whether to request a quotation.

Before manufacturing

No related continuation or divisional patents in force were found. Design patents, trademarks and unrelated patents may still cover the product.

Patent lapsed; practical issues include heat dissipation in conductive plate, wear of moving arm pivots, magnetic material sourcing, and verification that system meets local ride safety standards and certifications.

About 1.5% of lapsed patents are later revived by their owners. This page is a research lead, not legal advice. Obtain a freedom-to-operate opinion before manufacturing.

Claim 1, as granted

1. A trolley comprising: a wheel configured to rotate; one or more arms operably coupled to the wheel, the one or more arms configured to move from a closed position to a deployed position due to centrifugal force caused by rotation of the wheel; one or more magnets attached to each of the one or more arms, each magnet having a first surface that is closest to a corresponding arm of the one or more arms, a second surface that is farthest from the corresponding arm, and at least a third surface that connects the first surface with the second surface; and a plate made of non-ferrous conductive material and located adjacent to the second surface of each magnet of the one or more magnets when the one or more arms are in the closed position and the deployed position, wherein the movement of each of the one or more arms relative to the plate generates eddy currents that create magnetic fields opposing the rotation of the wheel, the plate having a first section and a second section, the first section being adjacent to the one or more magnets when the one or more arms are in the closed position, the second section being adjacent to the one or more magnets when the one or more arms are in an open position, a distance between the second surface of each magnet and the first section when the one or more arms are in the closed position being more than a distance between the second surface of each magnet and the second section when the one or more arms are in the open position.