Electronic search system
CA 2317533 A1 · Owner: Bergvall, Bengt Allan · Inventors: Petersson, Ulf; Bergvall, Bengt Allan
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An electronic search system (1) for a working tool (2) such as a lawn mower , or vacuum-cleaner in which system a border cable (a) is placed so that it separates an inner area (A) from an outer area (C). A first signal generator (3) feeds the border cable with current (Ia) whose magnetic field (7) affects , a sensing unit (8) located on the tool so that the sensing unit emits signals (9) to a control unit (10), which directs the tool's motion in order to prevent it from remoting from the inner area (A). The current (Ia) contains at least two alternating-current components (14 15) of different frequency. At , least one more cable called search cable (b, d, e) is placed within the inner …
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 December 30, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended December 30, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 30, 2020.
- 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.