Patent-pending mechanism, the four ‘Trébuchet Hammer’ can be seen striking on the backside. They devised a dual-axis-system with a special joint on a moveable arm.
Upon activation, the hammers are accelerated until they touch a small finger, whereupon a second moveable arm is released, thus helping to accelerate the hammers further shortly before the impact. This method utilizes around 80 percent of the force applied by the spring, whilst traditional hammer systems only deliver a mere 10 to 30 percent of the power originally applied.
The watchmakers also fitted a spiral spring for calibration and in this way created an easy method of adjusting the hammers with one screw.