US Patent 7854307 Electromagnetically actuated viscous clutch

A valve assembly (106) for an electromagnetically actuated viscous clutch (100) includes a cover plate (140) defining a seating portion configured to selectively cover an opening (138) from a reservoir (112), a flexible mounting plate (142), and an armature (144) that is movable in response to applied magnetic flux to move the cover plate (140) relative to the opening (138) from the reservoir (112). The armature (144) includes a base portion (146) connected to the cover plate (140) and the mounting plate (142), and a finger (148) extending from the base portion (146). The finger (148) and the base portion (146) define a path for conducting magnetic flux.