Draper header with flexible crop cutting knife

A crop harvesting header comprising:

• a frame extending across a width of the header for movement in a forward direction generally at right angles to the width across ground including a crop to be harvested;
• a mounting assembly for carrying the frame on a propulsion vehicle for up and down movement relative to the vehicle;
• a cutter bar arranged to move over the ground in a cutting action and carrying a sickle knife operable for cutting the crop as the header is moved forwardly across the ground;
• a draper transport system for moving the cut crop toward a discharge location of the header including at least one draper mounted on rollers generally parallel to the forward direction so that the draper carries the crop transverse to the forward direction, the draper having a front edge adjacent the cutter bar and a rear edge adjacent a rear of the frame;
• the cutter bar being mounted on the frame by a plurality of flexible blades at spaced positions along the frame, each of the flexible blades having a rear end rigidly attached to a rigid member of the frame and a forward end rigidly attached to the cutter bar so that the blades provide up and down floating movement by flexing between the rear end and forward end and the blades provide horizontal resistance to compression;
• wherein the frame comprises a center discharge portion at the discharge location of the header at which is located a fore and aft draper for carrying the cut crop rearwardly from the cutter bar to a discharge opening and wherein at least one of said flexible blades is connected to the cutter bar to allow said flexing thereof in the center discharge portion, and wherein said at least one flexible blade at the center discharge portion is shorter than others of the flexible blades.