a first blade (L1), supported stationary by a frame (S) for suspension and coupling to an operative vehicle (O);

a second blade (L2), slidingly connected to said first blade (L1) by mutual coupling means, and operated by actuating means (A) connected to said suspension frame (S), said second blade body being movable with respect to said first blade (L1) between a retracted position (R), in which a snow-removing surface of said snowplough blade (L) is at a minimum width, and an extreme advanced position (EA), in which the snow-removing surface of said snowplough blade (L) is at a maximum width, the snow-removing surface formed by said first blade and said second blade (L1, L2), being arranged one beside the other, said second blade (L2) being situated in front of said first blade (L1), the second blade (L2) having a width greater than or equal to a width of the first blade, and in that the operation of the second blade (L2) to said extreme advanced position (EA) determines the degree of sliding leftwards translation of the second blade with respect to said first blade (L1), and in that the snow-removing surface of the snowplough blade is formed only by the second blade when the second blade is in the retracted position (R), said first blade (L1) including a tubular cross-beam (1) connected to said suspension and coupling frame (S) and whose inner space is occupied at least partially by said actuating means (A), said actuating means (A) including a hydraulic jack housed inside said tubular cross-beam (1), functionally interposed between the tubular cross-beam (1) and said second blade (L2).