Needle coupling device for an agricultural baler

A baler comprising:

• a bale chamber;
• a plunger configured to compress crop material in the bale chamber in order to form a bale;
• a plurality of knotters;
• a needle yoke comprising a plurality of needles configured to deliver a plurality of lower strands through the bale chamber to the plurality of knotters;
• a tucker arm shaft carrying a plurality of tucker arms configured to deliver a plurality of upper strands to the plurality of knotters;
• a driving shaft located above the bale chamber and extending in a traverse direction of the baler, the tucker arm shaft extending parallel to the driving shaft;
• a gear box configured to continuously rotate the driving shaft when the baler is in operation, wherein the driving shaft is coupled with the gear box;
• a tucker arm coupling device configured to covert rotation of the driving shaft into a rotation of the tucker arm shaft, the tucker arm coupling device comprising a cam co-rotating with the driving shaft and a cam follower;
• and
• a needle coupling device configured for establishing a coupling and an uncoupling between the driving shaft and the needle yoke, and the needle coupling device configured to convert a rotation of the driving shaft into a movement of the needle yoke from a rest position to a twine delivery position and back such that the movement of the needle yoke is synchronized with the rotation of the tucker arm shaft,
• wherein the plurality of knotters are configured to receive the plurality of upper and lower strands from the plurality of tucker arms and from the plurality of needles, respectively.