it is the combination of the tine bars 80 each being mounted an equal tine distance d 5 from the central axis 88 and the asymmetry of the cam distances d 1 d 2 d 3 d 4 of the cam track 76 relative to the central axis 88 that causes the desired pivoting of the tine bars 80 it should therefore be appreciated that while the cam track 76 is shown as being an irregular circular shape that is arranged asymmetrically about the central axis 88 a similar effect could be achieved by arranging an irregular circular cam track centrally about the central axis 88 or by arranging a regular circular cam track asymmetrically about the central axis 88 i e so the circular cam track is not centered about the central axis 88 the maximum cam distance d 4 between the cam track 76 and the central axis 88 can be for example behind the cutter bar 34 there can be two similar cam tracks 76 and the associated links and rollers one on each end of reel 36 to assist in the fluid movement of tines 78 referring now to fig4 an additional embodiment of the present invention is shown which includes the cam track 72 shown in fig2 similar elements between fig3 and 4 are numbered similarly for ease of reference as can be seen the cam track 72 is a 180 degree flip of.