Aerodynamic profile for arrow or discus - has helical groove around shaft or peripheral surface to produce rotation and reduced resistance

摘要

The aerodynamic profile is applied to arrows, discuss and similar projectiles used in sporting activities. It is in the form of helical groove which is machined or moulded into the shaft of the arrow. In the case of a discuss, this groove is similarly produced around the peripheral surfaces of the projectile. The groove has a wide pitch between turns and is intended to reduce the air resistance on the surface and to improve the stabilising rotation of the projectile. It also flattens the and elongates the trajectory during its flight.