ELEMENTO A SARACINESCA SOLLECITATO DA MOLLA PER UNA MACCHINA PER CUCIRE PUNTI A CATENELLA

A sewing machine is provided with a cam (28) having a pair of intersecting cam tracks (52,54), a double pointed looper (16) which is carried by the cam, and mechanism for oscillating the looper including an actuator (26) to engage the cam tracks, and a spring biased slidable and pivotably movable gate (58) for controlling movement of the actuator between the tracks. The gate (58) has wings (74, 76) engageable by actuator (26) as it rises in the respective tracks (54,52) for displacing the gate to block the track, under the force of spring (66), below the actuator. The actuator then temporarily displaces the gate against the spring bias as it descends the track and the gate returns to prevent re-entry by the actuator when it rises again.