A counter knife bank assembly of a chopper assembly for an agricultural combine is provided that can pass obstructions without damaging the knife blades of the knife blade assembly. The counter knife bank assembly includes a knife bank and a lever assembly connected to the knife bank. The knife bank is moveable between a first position and a second position relative to a stationary frame of the chopper assembly. The lever assembly includes an extension member having a first end connected to the knife bank, a biasing member connected to the extension member, and an abutment member. The abutment member is engaged with the biasing member and is biased against a stationary support member of the counter knife bank assembly for articulation therewith.
