Abstract: The felling head is operatively installed at the front end of a tractor vehicle, and used for debrushing a brush covered terrain. It comprises a rigid framework, from which downwardly depends a pair of flat, spaced-apart elongated skates that slidingly rest on the ground and support the framework over ground. A pair of discoid saw blades are rotatably supported by the frame, with a ground clearance of a few inches relative to the plane of the skates. The framework is hingedly attached to the tractor vehicle by of a pair of linked parallel parallelograms forced into a common pivotal displacement, each having four rigid bars hingedly attached to one another so as to form a parallelogram configuration. A pair of hydraulic cylinders act on the parallelograms and on the frame, so as to allow vertical linear movement of the frame and a distinct vertical pivotal movement thereof.

Abstract: An endless spiralling screw for a snowblower comprising a rotatable elongated shaft, to be power driven; a first, elongated, rigid sheet, integrally mounted to the shaft at a radially inward edge of the sheet and spiralling along the lengthwise axis of the shaft, the main portion of the sheet having a substantially straight section, the external marginal portion of the sheet being folded relative to the main portion thereof, the plane of the main portion being located downstream relative to the direction of rotation of the endless screw; reinforcing struts being anchored to the spiral sheet and having a smaller external diameter than the spiral sheet, and being fixedly connected thereto short of but proximate to the radially outward edge of the spiral sheet and fixedly secured to the shaft at its radially inward edge at an area spaced from the securing area of the radially inward edge of the spiral sheet to the shaft; and counterweights, located inside the hollow of the spiral and integral to a portion of the