Metal ladder and method of fabricating the same
CA 1136104 A · Owner: Sears, Roebuck And Co. · Inventors: Stillman, Harold W. Jr.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
File No. 86-512, ABSTRACT OF THE INVENTION A metal ladder is fabricated from a pair of spaced rails in which the rails have web portions which are provided at spaced intervals with inwardly directed embossments. Each of these embossments has an opening into which one end of a tubular rung is inserted and swaged to the rail. The embossments act as ribs to carry the load toward the flanges constituting the stiffer portions of the rail thereby increasing the strength and effectively reducing the web flexure and angle changes between the rungs and the rails, due to sideward forces in ladder use. By reason of the built in stiffness web thickness may be reduced resulting in savings in materials. …
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 November 23, 1982. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 23, 1999.
- 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.