Originally Posted by
Efe Cem Elci
I am guessing the spring extends to the slider bold at the halfway point of the lever. This way, when it is pulled to move the lever up/down it extends and creates more force that will allow the lever to pop back in to the opposite groove.
On second thought, connecting to the axle bolt probably makes more sense as I'm guessing the slot the bolt passes through is wider to allow for the lever to move forward without being impeded by the axle bolt during the pulling movement.