Abstract: Plow windrow interruption by use of a folding auxiliary blade that is designed to overlay a portion of the plow main blade. The auxiliary blade is motivated to fold vertically pleatwise and, by alternating projection of the folded auxiliary forward of the trailing edge of the main blade, and a return to the overlying posture, respectively stop and reestablish the debris windrow.

Abstract: A plow blade having two oppositely pivoted/hinged sections that emulate a blade end. The sections alternately occupy a position coextensive to the blade. The sections are coupled to "gait" the movement of one with that of the other. One of the gates can only swing forward of the blade and the other can only swing rearward. When the forward (only) swinging section is thus situated, outflow off the blade is interrupted, i.e., dammed; and, as it returns to the blade coextensive position, it transfers dammed debris to the (coupled) rearward moving section for disposition into the windrow.