Closure means, e.g. end caps on header boxes or plugs on conduits

Filing statistics

CPC F28F 2220/00 belongs to the parent subclass F28F, which recorded 83,812 patent applications worldwide between 2013 and 2023. Annual filings declined from 7,008 in 2013 to 6,475 in 2023 (-8%), peaking at 8,704 applications in 2017. The most active applicants in class F28 are VALEO SYSTEMES THERMIQUES (1,945 applications), MITSUBISHI ELECTRIC CORPORATION (1,518 applications) and MAHLE INTERNATIONAL (1,120 applications).

Source: EPO PATSTAT, worldwide filings