DIFF Subgroup
E04H 12/28 Chimney stacks, e.g. free-standing, or similar ducts (chimneys as part of buildings E04F17/02)
Introduced: September 1968
Title
Titles differ between systems:
IPC: Chimney stacks, e.g. free-standing, or similar ducts
CPC: Chimney stacks, e.g. free-standing, or similar ducts (chimneys as part of buildings E04F17/02)
Full Title
Full titles differ between systems:
IPC:
Towers; Masts or poles; Chimney stacks; Water-towers; Methods of erecting such structures > Chimney stacks, e.g. free-standing, or similar ducts
CPC:
Towers; Masts or poles; Chimney stacks; Water-towers; Methods of erecting such structures (cooling towers E04H5/12; derricks for oil drilling E21B15/00) > Chimney stacks, e.g. free-standing, or similar ducts (chimneys as part of buildings E04F17/02)
No child classifications to compare. This is a leaf node in both IPC and CPC.