Telephone hand set transmitter with improved output response
CA 1069233 A · Owner: Northern Telecom Limited · Inventors: Robinson, Ronald C.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Abstract of the Disclosure, A conventional telephone handset transmitter is given a modified (improved) output response by providing an acoustic resistance path to and from the confined air chamber formed between the frame and the diaphragm of the transmitter, the acoustic resistance being less than conventional for example less than 40 ohms a maximum and approaching zero as a minimum. More than one aperture can be provided and a, tube may surround an aperture to provide some inertance to air flow. - 1 -
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 January 1, 1980. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 1, 1997.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
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.