A cutting device includes a cutting mechanism, a hitching structure designed to be connected to a motor vehicle, a support beam joined to the hitching structure and to the cutting mechanism and a traction device. The traction device is comprised of at least one draw-spring designed to lighten the cutting mechanism during operation and a control device designed to void the action of the at least one draw-spring when the cutting device is placed. The control device has, among other things, a rod at one of the ends to which the at least one draw-spring is attached. The control device is comprised of a cylinder which has the rod, a body, a piston which separates the body into first and second chambers, and a fluid circuit which has a device which allows the fluid to enter the first chamber located on the side of the at least one draw-spring when the latter must be tightened, and allows the fluid to leave the first chamber when the at least one draw-spring must be relaxed.