Patent ID: 6912835

Claim:
In a crop cutting device including a support frame having opposite side walls, a knife bed extending between the side walls and provided with a plurality of parallel, elongate slots extending in a direction of travel of the cutting bed, a plurality of knives mounted beneath said knife bed respectively in vertical alignment with said elongate slots and for pivoting vertically between a lowered non-working position, wherein cutting edges of said knives are located substantially at said elongate slots, and a raised working position, wherein said cutting edges project substantially entirely above said knife bed, a safety trip device associated with each knife and including resiliently yieldable member movable between an extended position, wherein it retains an associated knife in its working position, and a yielded retracted position wherein said associated knife is permitted to move to its non-working position, and a selector mechanism for selectively blocking certain safety trip devices in their retracted positions, the improvement comprising: said selector mechanism including a rotatably mounted rotor extending adjacent said safety trip devices and having at least two different selector arrangements which are selectively movable into positions for blocking different numbers of said safety trip devices in their respective retracted positions.