the length of a moment arm furthermore to facilitate a smooth but rapid transfer of energy to the arrow take up levers 118 and 120 may include a curvilinear profile whereby a cam like shape of the levers coincides with the power curve necessary to overcome inertia and provide a non linear force to account for the acceleration of the arrow this feature takes into consideration that an arrow at rest initially requires high energy low velocity whereas in contrast a moving arrow needs a low energy increasing velocity as it gains speed the disclosed embodiments rely on the laws of motion to essentially regulate the power transfer in response to the reactive or resistive forces from the bow mechanics and the arrow according to the disclosed embodiments an initial displacement force is applied by the user between forward hand grip 104 and rearward hand grip 106 providing an energy input into spring motor or assembly 122 that serves as a potential energy buffer or reservoir the device intentionally requires that the energy to move the drawbar or handle 104 rearward requires a generally constant force over the range of movement from an at rest position in front of the riser 102 e g fig1 to a fully drawn position rearward of riser 102 e g fig2 in other words the generally continuous force requirement does not require or exhibit.