Expired, full termArchiveSolo inventor
Device for breaking down coal
US 1,900,446 A · Inventors: JOY JOSEPH F
Overview
3 drawing sheets
Every sheet is in the USPTO PDF.
Open the USPTO PDFRead 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.
Why it's free to use
- Granted March 7, 1933. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by March 7, 1950.
- We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledOctober 13, 1931
GrantedMarch 7, 1933
Term endedMarch 7, 1950
Application number—
Classification (CPC)E21C37/10
Length7 pages
Sources & verification
Official USPTO records
Cross-check elsewhere
Everything on this page comes from the USPTO record linked above.