Thread control for overedge sewing machine

In an overedge sewing machine including a frame, a thread-carrying needle, a needle arm supporting said needle for oscillatory movement in a first vertical plane extending in the direction of movement of work through the machine, a thread-carrying lower looper, a lower looper carrier supporting said lower looper for oscillatory movement in a second vertical plane extending at right angles to said first vertical plane, an upper looper, an upper looper carrier supporting said upper looper for recripocal and oscillatory movement along a line disposed in a third vertical plane extending parallel to said second vertical plane, means driving said needle arm and said lower and upper looper carriers to move said needle and said loopers in synchronization with one another to interloop the threads carried thereby to form an overedge seam, and first thread takeup means for controlling the thread carried by said lower looper, said first thread takeup means comprising spring biased thread tension means mounted on said frame, a plurality of stationary thread guides mounted on said frame, a first movable thread guide mounted on said lower looper carrier for oscillatory movement therewith, a second movable thread guide mounted on said upper looper carrier for oscillatory and reciprocal movement therewith, said first movable thread guide including means adapted to engage the thread carried by said lower looper during its oscillatory movement, said second movable thread guide including means movable in a path to engage a length of thread extending between two of the other of said thread guides during at least a portion of said oscillatory and reciprocal movement, said first and second movable thread guides cooperating with said tension means, said stationary thread guides, and said lower looper to control takeup of the lower looper thread.