INDEXING SCHEME RELATING TO ASPECTS OF THE CHARGES OR FURNACES, KILNS, OVENS OR RETORTS

Description

F27M serves as an indexing classification for organizing patents related to the operational and physical characteristics of furnaces, kilns, ovens, and retorts, as well as their processed materials (charges). This subclass provides systematic cross-referencing for documents addressing specific aspects such as heating methods, charge composition, furnace design features, or operational parameters rather than constituting a primary classification category itself. Patents are typically assigned to F27M in conjunction with more specific technical subclasses (e.g., F27B, F27C, F27D) to enable comprehensive retrieval by patent practitioners and examiners searching across multiple technical dimensions of thermal processing equipment.

Filing statistics

CPC subclass F27M recorded 3,732 patent applications worldwide between 2013 and 2023. Annual filings grew from 52 in 2013 to 359 in 2023 (+590%), peaking at 571 applications in 2021. The most active applicants in class F27 are POSCO (POHANG IRON AND STEEL COMPANY) (930 applications), JFE STEEL (771 applications) and PAUL WURTH (518 applications).

Source: EPO PATSTAT, worldwide filings