Patent Yard Sign in
Expired, full termArchiveSolo inventor

Preparation of ferro-chromium in blast furnaces

US 2,280,452 A · Inventors: ROYSTER PERCY H

USPTO PDF

Overview

This document has no drawings.

Claude can sketch it from the patent text.

Read the whole patent

Listed from its USPTO record in Patent Yard's full-term archive. Its claims, description and drawings are in the USPTO PDF and on Google Patents, and the Claude kit works from them.

Google PatentsUSPTO PDF

Why it's free to use

  • Granted April 21, 1942. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by April 21, 1959.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledApril 10, 1941
GrantedApril 21, 1942
Term endedApril 21, 1959
Application number—
Classification (CPC)C21B5/02
Length3 pages

Sources & verification

Official USPTO records

Full published documentText and every drawing sheet as a PDF.USPTOFile historyStatus, office actions, notices, fee records and petitions.USPTO Patent CenterPatent Public Search recordSearchable full text and bibliographic data.USPTO

Cross-check elsewhere

Google PatentsFull text, worldwide family, citing patents and legal events.patents.google.comJustia PatentsFull text, claims and classification.patents.justia.comFreePatentsOnlineFull text and PDF.freepatentsonline.comEspacenetForeign family and legal status.European Patent Office

Everything on this page comes from the USPTO record linked above.