Loading Mechanism of a Bench Crossbow
A rack-and-lever gear for spanning a mounted crossbow, parts A, B, C, F, N
A long narrow sheet drawn in side view showing a bench-mounted crossbow (balestro a banca) with its spanning gear laid out beneath the stock. Leonardo's note explains how a foot-worked lever at point A raises and lowers a toothed rack (scaletta) that a support N drives into the hook F, holding the string until release; sending the support to C and driving in the screw B frees the rack so the nut can return by the cord. He adds that the point N should sit below the nut and that this arrangement works better than pulling with a cord.
On this page
How the bench crossbow is spanned
Grip the foot-lever at A and raise and lower it; the support N pushes the toothed rack into the hook F, where it stays until you shoot. To let the nut return along the cord, move the support to C and drive in the screw B, and the hook F releases the rack.
Placement of the release parts
A caption keyed to the drawing marks the sequence B-F-C-N and states that this works better than a cord and pulling. Leonardo specifies that the point N should lie directly below the point of the nut (noce).