Particle dispenser with fluid assist to control particle velocity for use on a moving vehicle

Abstract

When mounted to a vehicle, a dispenser ejects optical elements so that they have a component of movement that is parallel with the surface of the pavement to which the optical elements are to be applied. Preferably, the component of movement in that direction is more significant than a component of movement directly toward the pavement surface. A fluid assist causes the optical elements to be ejected from the dispenser nozzle at a velocity to at least partially counteract, and preferably match, the forward velocity of movement of the vehicle to which the dispenser is attached. Thus, in accordance with one specific aspect of the present invention, optical elements can be laid down upon marking material that has been applied to a pavement surface at a substantially reduced relative velocity to the road surface. By more closely matching the optical element velocity in a direction opposite the vehicle movement to the velocity of the vehicle, the optical elements can be laid down without substantial roll along the pavement marking material. This can be accomplished regardless of the size or mass of the optical elements. The result is that the retroreflectivity of the pavement marking is thus not compromised or negatively affected in either direction (i.e. in the direction of vehicle travel or in the opposite direction).