Method of and device for manufacturing curved helical springs
CA 2100422 C · Owner: Fried. Krupp Ag Hoesch-Krupp · Inventors: Vondracek, Hans; Krober, Heinz
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The objects are a reliable and economical method of and device for manufacturing helical springs that are curved when unstressed from sections of wire or rod heated to coiling temperature. The spring is coiled straight and then curved it to its final shape. The device consists of a hot-coiling production line comprising a kiln (1), a series of rollers (2), a coiling bench (4), and a quenching tub (6). A tool (5) for curving helical springs (10 or 14) is integrated into the production line between the coiling bench and the quenching tub.
Read the whole patent
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 July 13, 1993 and granted September 26, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended July 13, 2013.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by July 13, 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.