The invention relates to a clamping device with a knee-joint making it possible to move one jaw in a composite rotational movement and with a reduction in the force provided by the user. It consists of a body 1 equipped with a fixed jaw 2 and a blade 3 moving in a slot 5 of the body 1 and guided by a small rod 6 articulated to the body 1. When the user exerts a force on the moving arm 4, it causes the movement of the blade 3 by means of the small rod 7. Handles 10 and 11 with double positions for the hands allow combined grasping of the assembly. The device according to the invention is particularly intended for cutting vines.
