a suitable time so as to maintain at a constant position the intersection of the lower cross thread 31 with another associated upper cross thread 30 with continuing reference to fig2 the second longitudinal swing member 19 is mounted by a fulcrum pin 19 39 to the base plate 1 and has at its forward end portion an arcuate upper cross thread guide piece 19 34 having thread holes 22 and 22 39 and a needle like extreme end the second longitudinal swing member 19 with the upper cross thread 30 passed through the guide piece 19 34 is longitudinally swung at a suitable time so as to engage the upper cross thread 30 with the needle thread 40 passed through the needle 8 on the upper surface 39a of the cloth 39 for completing overcasting stitches as may be seen in fig7 and 9 at this time the needle point 8 39 of the needle 8 passes through an arcuate configuration 30 34 defined by the upper cross thread 30 and the guide piece 19 34 as best seen in fig9 the third longitudinal swing member 20 is mounted by a fulcrum pin 20 39 to the base plate 1 as shown in fig2 and a lower cross thread guide piece 23 which will be hereinafter described is attached to the forward end of the third longitudinal swing member 20 as may be seen in fig4 6 7 8 9 and 10 the lower cross thread guide piece 23 with the lower cross thread 31 passed through a thread hole 23 34 provided at the extreme end 23 39 thereof is given vertical swing b.