Vacuum-Energized Make-and-Break Spark-Plug. (open access)

Vacuum-Energized Make-and-Break Spark-Plug.

Patent for a vacuum-energized make-and-break spark plug that "relates to new and useful improvements in ignition apparatus for internal combustion engines" (lines 16-18) including instructions and illustrations.
Date: June 4, 1918
Creator: Irwin, Herbert Glen
System: The Portal to Texas History
Vacuum-Operated Make-and-Break Spark-Plug. (open access)

Vacuum-Operated Make-and-Break Spark-Plug.

Patent for simple and efficient improvements to vacuum-operated make-and-break spark plugs, including illustrations and instructions.
Date: June 10, 1919
Creator: Irwin, Herbert Glen
System: The Portal to Texas History