Abstract: A blank (12′) of high-ductility material is formed with closely spaced thin fins (14) using a forming tool (18) which is rotatable about a tool axis (L) and comprises a set of flat circular space-apart forming discs (19) centered on the tool axis (L) and disposed side by side at fixed intervals along the tool axis (L) and in planes perpendicular thereto. The forming tool is displaced relative to the blank (12′) at right angles to the tool axis (L) to cause the peripheral portions of the forming discs (19) during the cyclical movements of the forming tool (18) progressively to penetrate into the blank (12′) and cause blank material to flow into the gaps separating the forming discs (19) and form planar fins (14).

Abstract: A filter and heat exchanger device comprises a substantially cylindrical housing (11) accommodating a tubular heat exchanger body (31) having fins (35) on the outer side thereof and an axial through passageway (32, 33) communicating with secondary-liquid inlet and outlet ports (19, 20). A heat exchanger compartment (26) inside a cylindrical partition (28) in the housing (11) accommodates the heat exchanger body (31) and a filter compartment (27) outside the partition accommodates a filter body (30). The two compartments (26, 27) communicate with one another and form successive sections of a primary-liquid flow path extending between primary-liquid inlet and outlet ports (17, 18). An elongate opening in the partition (28) is substantially coextensive with the heat exchanger body (31) and defines a flow passage (29) which interconnects the heat exchanger and filter compartments (26, 27).