CV drive shaft construction

A constant velocity drive shaft for carrying center universal joint of drive shaft adapted to maintain equal angles when turning up to 90 degrees, for transmitting power from a vehicle to a driven mechanism located on an implement, said construction comprising a first shaft having a first end and a second end, said first end coupled to the driving shaft of the vehicle, a second shaft having a first end and a second end, said first end coupled to said second end of said first shaft by a first universal joint and said second end of said second shaft adapted to be coupled to the driven shaft of the implement by a second universal joint;

• and a positioning structure including a first frame disposed adjacent said first universal joint and a second frame disposed adjacent said second universal joint, said first shaft being rotatably coupled to said positioning structure so that said first shaft is maintained substantially perpendicular to said first frame in the horizontal plane, said first and second frame members connected by a pair of elongated links, each of said links pivotally secured at opposite ends to each of said frames, said links diagonally crossing one another as they extend between said frames, said positioning structure adapted to maintain an angle between said first and second shafts substantially equal to an angle between said second shaft and the driven shaft of the implement in the horizontal plane;
• the shaft construction wherein each of said links includes two substantially parallel bars with one of said bars positioned above said second shaft and the other of said bars positioned below said second shaft, wherein the pivot axes of said first universal joint lie in a substantially vertical plane that intersects the connection locations of said links to said first frame when said first and second shafts are aligned, wherein the pivot axes of said second universal joint lie in a substantially vertical plane that intersects the connection locations of said links to said second frame when said first and second shafts are aligned, wherein said first shaft is coupled to said positioning structure by connecting means for allowing said first shaft to pivot up and down in a substantially vertical plane, wherein said connecting means includes two parallel arms pivotally attached adjacent opposite sides of said first frame, the connection locations of said arms lying in a substantially vertical plane that intersects the connection locations of said links to said first frame, wherein said positioning structure is attached to the implement by an attaching bracket, said attaching bracket being pivotally secured to the implement and rigidly secured to said positioning structure so that said positioning structure is allowed to move longitudinally in response to relative motion between the implement and the vehicle, wherein the distance between the connection locations of said links to said first frame are substantially the same as the distance between the connection locations of said links to said second frame, wherein the distance between the connection locations of said links to said first frame is less than the distance between the connection locations of said links to said second frame.