DIFF Subgroup
E21D 19/02 for use in longwall working
Introduced: September 1968
Full Title
Full titles differ between systems:
IPC:
Provisional protective covers for working space > for use in longwall working
CPC:
Provisional protective covers for working space (E21D9/06, E21D23/00 take precedence) > for use in longwall working
No child classifications to compare. This is a leaf node in both IPC and CPC.