Two stage knife floor

A harvesting machine, comprising:

• a main frame;
• a rotor assembly rotatably coupled to the main frame and configured to move crop material;
• a top frame movably attached to the main frame, the top frame forming a passageway for crop material between the top frame and the rotor assembly;
• a bottom frame movably attached to the top frame or main frame;
• a plurality of knives movably attached to the bottom frame or the top and bottom frames, the plurality of knives extending through slots in the top frame, the bottom frame engaging an indentation on a non-cutting edge of the knives to maintain the plurality of knives in a locked condition, and the bottom frame disengaging from the indentation in one or more of the plurality of knives so that the knives can rotate away from the rotor assembly in a tripped condition;
• an actuator operatively connected to one of the top and bottom frames, the top and bottom frames in a raised position when the actuator is in a first position, and bottom frame moving to a lowered position relative to the top frame when the actuator is in a second position causing the bottom frame to reengage the indentation on the non-cutting edge of the knives, which returns the knives to the locked condition;
• further comprising a limit stop assembly operatively connected to the top frame and to the bottom frame, wherein the limit stop assembly includes a first stop configured to limit travel of the top frame with respect to the main frame and a second stop configured to limit travel of the bottom frame with respect to the top frame.

A harvesting machine, comprising:

• a main frame;
• a rotor assembly rotatably coupled to the main frame and configured to move crop material;
• a top frame movably attached to the main frame, the top frame forming a passageway for crop material between the top frame and the rotor assembly;
• a bottom frame movably attached to the top frame or main frame;
• a plurality of knives movably attached to the bottom frame or the top and bottom frames, the plurality of knives extending through slots in the top frame;
• no more than two actuators operatively connected to the top and bottom frames, the top and bottom frames and the plurality of knives being in a raised position when one actuator of the no more than two actuators is in a first position, and the top and bottom frames and the plurality of knives being in a lowered position when the one actuator is in a second position, which enlarges the passageway between the top frame and the rotor assembly and at least partially retracts the knives through the slots in the top frame;
• Wherein the top frame is pivotably coupled to the main frame at a main frame pivot, and the bottom frame is pivotably coupled to the top frame or main frame at a bottom frame pivot;
• a limit stop assembly operatively connected to the top frame and to the bottom frame, wherein the limit stop assembly includes a first stop configured to limit travel of the top frame about the main frame pivot and a second stop configured to limit travel of the bottom frame about the top frame pivot;
• and
• wherein the limit stop assembly includes a main frame portion defining the first stop and a link defining the second stop, wherein contact of the top frame with the first stop limits the travel of the top frame, and wherein contact of the bottom frame with the second stop limits travel of the bottom frame.