Steel composition for suspension springs
CA 2088385 C · Owner: Max Aicher (North America) Realty Inc. · Inventors: Head, Melvin Edward; Millar, Gordon Douglas; Asseiro, Anthony Manuel
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A steel composition is provided having improved sag resistance and fatigue behaviour properties adapting it to be suitable for coil and torsion bar suspension springs for passenger vehicles and light trucks of lesser weight. Critical to the composition is the use of vanadium in an amount of from about 0.05 to about 0.50 wt% or niobium in an amount of about 0.05 to about 0.20 wt%, sufficient nitrogen to ensure that the vanadium or niobium is in the form of vanadium nitride or niobium nitride respectively and the substantial absence of aluminum. The vanadium nitride or niobium nitride ensures fine grain formation and the improved properties. Other components may be present including carbon …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed January 29, 1993 and granted May 5, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 29, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 29, 2015.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.