Moving screens not otherwise provided for, e.g. swinging, reciprocating, rocking, tilting or wobbling screens jigging or moving to-and-fro {within their own plane} in or approximately in {or transverse to} the direction of conveyance
Moving screens not otherwise provided for, e.g. swinging, reciprocating, rocking, tilting or wobbling screens jigging or moving to-and-fro {within their own plane} in or approximately in {or transverse to} the direction of conveyance