back blade 10 this is usually not an issue of concern because reverse operation of the vehicle is not generally necessary to occur over any substantial distance however any snow that overtops the plow back blade 10 is very loose and easily captured by the back surface 102 of the snow plow blade 100 the plow back blade 10 shown in fig3 includes a scraper blade 20 that may be integral with or attached to support arms 60 the support arm 60 has a free end and a fixed end by way of example the support arms 60 shown as an angle iron may also be channel or tube with a circular or rectangular cross section the support arm 60 may be straight or arced in either a longitudinal or lateral direction the support arm 60 fixed end is attached to the scraper blade 20 by welding bolting or other known means the support arm 60 free end includes a pivot point 65 for pivotably connecting the plow back blade 10 to the structural member 105 examples of a pivotal connection include a pin bolt bearing assembly or rivet the support arm 60 is typically pivotably attached to a structural member 105 on the back surface 102 of the snowplow blade 100 or directly to the back surface 102 preferably at approximately the vertical midpoint of the snowplow blade 100 the working face 25 of the scraper blade 20 facing the vehicle has an upper edge 21 and a lower edge 22 the upper edge 21 position is determined by the geometry of the support system.