Push buttons
CA 1109974 A · Owner: Stc Plc · Inventors: Cragg, William D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A push-button operated electrical switch includes a push-button adapted to be operated by a user and a dome-shaped member formed from a piezo-electric plastics sheet. The sheet has electrically conductive film electrodes on both of its faces, and the push-button has a shank aligned with the dome so that when the push-button is depressed the end of its shank acts on the curved apex of the dome to depress the dome. The end of the pushbutton shank is curved, the relation between the curvature of the shank end and the curvature of the dome being so chosen as to give the push-button the desired operating characteristics. The distortion of the dome which occurs as a result of the depression of …
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 September 29, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 29, 1998.
- 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.