A baler including a bale chamber； a plunger configured to compress crop material in the bale chamber in order to form a bale； a needle yoke with a plurality of needles configured to deliver twine through the bale chamber； a plurality of knotters configured to receive the twine from the plurality of needles； a bale length measurement and trigger device configured to measure the length of the bale in the bale chamber and to generate a trigger when a predetermined length is reached； a driving shaft located above the bale chamber and extending in a traverse direction of the baler； a needle coupling device between the driving shaft and the needle yoke, the needle coupling device being configured for moving the needle yoke from a rest position to a twine delivery position and back, when the bale length measurement and trigger device generates a trigger.
