Square-backed vehicle air foil system

摘要

The specification describes a preferred embodiment of the square-backed vehicle air foil 10 for attaching to a vehicle 12 adjacent an upper rear edge 21 for projecting into a horizontal airstream "S" for subdividing the airstream into an inner or first airstream layer S1 and an outer or second airstream layer S2. The assembly 10 has an inner air foil element 32 that directs the first airstream layer rearward and then rearward and downward over the rear edge 21 and then downward at a first velocity along the rear vehicle panel 21 to form a first air curtain along the rear panel to keep the rear panel clean. The assembly 10 has an outer air foil element 34 that, in cooperation with the inner foil element 32, directs the second airstream layer S2 rearward along the roof panel while accelerating the layer S2. The layer S2 then is directed rearward and downward over the rear edge 21 and is then directed downward along the rear panel at a higher velocity than the first layer forming a second air curtain for keeping the rear panel clean. A frame 30 attaches the assembly 10 to the vehicle 12 projecting the inner and outer foil elements 32, 34 into the airstream to receive the first and second airstream layers S1 and S2. The mounting frame 30 provides for longitudinal and transverse adjustment of the assembly 10.