Covering for a ground opening
CA 1305598 C · Owner: Spiess, Hansruedi · Inventors: Galvanetto, Francois; Spiess, Hansruedi
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A covering comprises a cover and a frame into which the cover is inserted. A supporting surface of the cover and a cooperating bearing surface of the frame each have a surface inclined with respect to the cover plane. These surfaces are partial peripheral surfaces of a sloping cylinder and or a sloping cone bounded by sections. As a result the partial surfaces have along their circumferences a different inclination with respect to the cover plane. Therefore the cover can only be inserted in the frame in a specific position. Since as a result of this the same surface portions of the cover and the frame always rest on one another, in the case of such coverings a tight closure can be achieved …
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
- Granted July 28, 1992. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended July 28, 2009.
- 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.