Patent ID: 6708476
Filing Date: 2004-03-23
Classification: A01D

Abstract:
A mowing device comprising in combination:a frame structure adapted for forward travel over ground having standing crop thereon, said frame structure including a flange extending forwardly along a plane generally transverse to direction of forward travel; a cutterbar assembly mounted to said flange and extending along the transverse length of said flange from a first end to a remote second end thereof, said cutterbar assembly including: a plurality of substantially uniform-length knife guards affixed in transverse alignment to said flange and projecting forwardly therefrom; first and second conversely reciprocating elongate sickle bars, said first sickle bar having a first elongate knife back and said second sickle bar having a second elongate knife back, each having outboard and inboard ends and upper and lower surfaces operable within said knife guards, said sickle bars being disposed in generally transverse alignment; said first sickle bar and said first knife back of substantial equal length greater than one-half the transverse length of said cutterbar assembly and extending generally from said first end of said cutterbar assembly toward the second end thereof; knife elements mounted on the upper surface of said first knife back and co-operable with a plurality of said knife guards for cutting crop material, the knife elements being mounted on said first knife back in transverse alignment, the leading edges of said first and second sickle bars lying in substantially the same vertical plane; said second sickle bar extending generally from said second end of said cutterbar assembly toward the first end thereof, said second sickle bar being disposed one knife element thickness above said first sickle bar; said second knife back having a length less than one-half the transverse length of said cutterbar assembly and extending generally from said second end of said cutterbar assembly toward the first end thereof; knife elements mounted on the upper surface of said second knife back and co-operable with a plurality of said knife guards for cutting crop material, the knife elements being mounted on said second knife back in transverse alignment; a knife back extension having upper and lower surfaces mounted on the upper surface adjacent the inboard end of said second sickle bar and extending away therefrom over the inboard portion of the upper surface of said first sickle bar in transverse alignment with both said first and second sickle bars; knife elements mounted on the lower surface of said knife back extension and co-operable with a plurality of said knife guards for cutting crop material, the knife elements being mounted on said knife back extension in transverse alignment such that said knife back extension and said second knife back sandwich a plurality of knife elements where they overlap; the relative lengths of said first and second sickle bars being such that said knife back extension is always in an overlap position relative to the said inboard end of said first sickle bar; a drive mechanism on said frame structure for providing oscillatory motion; and mechanical connection apparatus connecting said drive mechanism to each outboard end of said sickle bars for transferring oscillatory motion thereto to cause reciprocation thereof.