Machine for softening and stretching laminar products, particularly tanned hides

A machine for continuously softening and stretching flexible laminar products having opposite side surfaces, said machine comprising a frame supporting at least one pair of facing plates arranged on opposite sides of the flexible laminar products under treatment, one of said plates being stationary with respect to the frame, the other said plate being movable in a direction substantially perpendicular with respect to the one said plate and to side surfaces of the products, means for oscillating said movable plate with a predetermined frequency between a first position at a minimum distance from said stationary plate and a second position at a maximum distance from said stationary plate, a pair of flexible conveyor belts arranged between said plates to contact and engage the opposite sides of the products to cause advancement thereof in a direction substantially parallel to said plates, wherein one of said plates is a substantially rigid planar support which is covered with a substantially uniform layer of elastically yielding material having no interruption and no rigid projection, the other plate being provided with a plurality of substantially rigid protruding elements adapted to interact with said uniform layer of the one said plate, said uniform layer having a thickness at least equal to the distance between said first and second positions so as to permit full penetration of said protruding elements to a certain depth of penetration, said protruding elements having a substantially curved shape with a radius of curvature greater than said depth of penetration, so that the products under treatment are subject to a substantially uniform stretching action with no concentration of stress, thus reducing the risk of marking and permitting safe increases in depth of penetration and frequency of oscillation of said plates.