Patent Yard Sign in
Expired, full termArchiveSolo inventor

Tunneling apparatus

US 1,338,237 A · Inventors: MACK JAMES O

USPTO PDF

Overview

The published document from the USPTO: abstract, claims, description and drawings. Open it full size

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.

Why it's free to use

  • Granted April 27, 1920. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by April 27, 1937.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledMay 21, 1918
GrantedApril 27, 1920
Term endedApril 27, 1937
Application number—
Classification (CPC)E21D9/10
Length13 pages

Timeline

Timeline From USPTO dates

1919192119231925192719291931193319351937Application filedMay 21, 1918Patent grantedApril 27, 1920Term endedApril 27, 1937

Sources & verification