Spring coupler for block and tackle window balance system
CA 1290194 C · Owner: Flight, Robert S. · Inventors: Newton, William P.; Flight, Robert S.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A coupler connects end regions of different sizes of coiled tension springs 30 and 40 to components of block and tackle window balance systems 10. Each coupler 15, 20, or 25 has a snug fit within terminal coils 41 of the strongest spring 40 having the smallest inside diameter, and weaker spring 30 with a larger inside diameter has its terminal coils 31 necked down to fit the coupler. The coupler has a notch or opening with an abrupt edge 18, 22, or 28 axially spaced from an end of the coupler so that the notch is at least twice as long as the largest wire diameter used in the coil springs. At least one of the terminal coils of each spring is indented into the notch or opening in the coupler …
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 October 8, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 8, 2008.
- 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.