Abstract: A mechanical accelerating device (1) for projectiles, especially for arrows and bolts, has a bow holder, at least two elastic bows (2) attached to the bow holder, each of the bows (2) being engaged by a bow string (3), and at least one additional string (4) connecting the bow strings, the force of the bows acting on the actual projectile by the additional string (4) at a force transfer point (6). Therein, according to the invention each bow (2) is pivoted at the bow holder rotatably about a rotation axis (5), so that in drawing the accelerating device (1) the bows (2) orientate to the actual force transfer point (6).