Patent ID: 8510959

Claim:
A mechanism for removably attaching a knife to a rotary disc used on a disc cutterbar on an agricultural mower comprising: a disc head configured for rotation about an operating axis, said disc head having an outer portion; an elongate retention mechanism connected to said outer portion and oriented on a pivot axis generally parallel to said operating axis, said retention mechanism having a shank portion and a head portion; and an elongate and generally planar knife having opposing inner and outer ends, a planar thickness, and an aperture penetrating said planar thickness of said knife and disposed adjacent to said inner end, said aperture further comprising a first zone and a second zone, said aperture configured to engage said shank portion in a manner to locate said knife in a first position when engaging said first zone and a second position when engaging said second zone, said first zone disposed outwardly of said second zone and configured to allow passage therethrough of said head portion, said second zone configured to engage said shank portion of said mounting structure and prevent passage therethrough of said head portion; a biasing element connected to said disc, said biasing element configured to urge said knife outwardly from the operating axis into said second position.