means 42 through the medium of the rocker link 110 drive links 100 and 102 and feed dog carrier 46 also the construction of the rocker drive link 110 allows it to act as a means for thrusting the main feed bar 46 and its respective drive links in one lateral direction as may be best viewed in fig1 when considering the kinematics of the first linkage assembly 94 it is evident that the affect of oscillating the thrusting rock drive shaft 84 is that oscillatory movement will be created at point 108 on rocker link 110 which is constrained to move along the arc of a circle generally indicated as 112 the rocking motion of the drive link 110 is resolved into endwise movement of the feed bar 46 by the drive links 100 and 102 that is the rocking motion of the drive link has a horizontal component of movement that is imparted to the drive link 102 the point 106 whereat the link 102 is connected to link 100 is constrained to move along a predetermined path generally in the arc of a circle indicated at 114 owing to a positive guiding by an anchor link 116 the function and operation of anchor link 116 will be discussed hereinafter because link 100 is pin connected to the drive link 102 the drive link 100 is obliged to move with the driven link 102 and imparts a.