Strut with spring seats on upper and lower bearings
A MacPherson-type strut that places the coil spring between two bearing assemblies so both spring seats rotate independently of the damper cylinder. The lower spring seat is mounted to a lower bearing around the damper cylinder so the spring end can spin during compression, intended for vehicles with front strut/knuckle assemblies. Typical users would be vehicle OEMs or aftermarket suppliers of replacement struts and top mounts.
(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 covered a strut assembly having a damper cylinder, piston rod and coil spring, plus an upper bearing assembly and a lower bearing assembly, where the coil spring extends between and is seated on those bearing assemblies and the lower end of the coil spring is seated to the lower bearing so that it freely rotates about the damper cylinder when the spring is compressed. The assembly thus requires both upper and lower bearing seats and a freely rotating lower spring end around the damper cylinder.
Distinguishing feature: Positioning a lower bearing with a lower spring seat that allows the lower end of the coil spring to rotate freely around the damper cylinder during compression to reduce torque transfer to the knuckle.
Novelty 3/5. Reducing spring-induced torque on the strut/knuckle was a known problem; the patent applied a dual-bearing approach (both upper and lower spring seats on bearings) rather than a single fixed spring seat, which is a practical improvement over typical strut designs.
Manufacturing
Damper cylinder and piston rod manufactured by machining and welding; coil spring formed from heat-treated cold-wound high-carbon steel; upper and lower bearing assemblies produced by stamping and bearing insert assembly; final assembly by press-fitting/staking of bearings and hand or robotic assembly of spring onto strut.
Materials: Stamped or cast steel damper cylinder/strut housing, Hardened steel piston rod, Elastomeric or stamped steel spring seats, High-carbon coil spring steel.
Manufacturability 4/5. Requires several stamped/cast metal parts, bearing inserts and controlled assembly to ensure bearing alignment and free rotation of the lower spring seat; uses common automotive suppliers and tooling.
Market demand
Comparable products are on sale; this exact design was not found. Manufacturers and aftermarket suppliers offer rotational/bearing-enabled upper spring seats and rotating strut components; multiple listings reference rotational bushings or bearings paired with upper spring seats for MacPherson struts; some listings are OEM-style assemblies and aftermarket equivalents.
- Monroe Quick-Strut for Ford F-150/Expedition (rotational bushing... · Monroe Shocks & Struts
- Radial Bearing Upper Spring Seat Pair · FEAL Suspension (radial bearing upper spring seats for MacPherson-style suspensions)
- Steerable suspension bearing assembly (MacPherson strut bearing... · General Motors / various patent holders (commercial bearing assemblies used in OEM front MacPherson struts)
Demand check by web search, week of Oct 12, 2026. Listings change frequently.
Buyers: Automakers, aftermarket strut suppliers, suspension shops.
Sourcing
No factory listings were found on the major supplier marketplaces. Production would likely require custom tooling or a direct approach to a manufacturer. No listings found on Alibaba.com, Made-in-China.com, Global Sources, or DHgate that match a dual-bearing rotating-spring-seat front strut exactly. What we did find were generic spring-seat or strut-bearing components without visible unit prices or MOQs, not factories listing a close-on-product for OEM/aftermarket dual-bearing assemblies.
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; ensure compliance with vehicle-specific fitment, NVH tuning and bearing load ratings; claim scope focused on the lower spring seat freely rotating about the damper cylinder, which is relatively specific.
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.