Lopping machine for stems of trees

A lopping machine for stems of trees, which machine comprises an annular holder frame having an interior surface bounding a central opening for longitudinal passing of a tree stem to be lopped, said interior surface being frusto-conical and its diameter decreasing in the direction of movement of the tree stem, and a plurality of lopping rods each having a cutting end, said lopping rods being mounted in said annular holder frame with the cutting ends spaced apart from one another about the central opening and with each lopping rod being directed towards the central axis of the opening obliquely against the direction of movement of the tree stem, and each lopping rod being slidable in the axial direction thereof between a lopping position in which its cutting end projects through said interior surface into said central opening and a retracted position in which its cutting end is withdrawn from the central opening to a position beyond said interior surface, and the machine also comprising means connected to said rods for displacing said rods forcibly from said retracted position to said lopping position to engage a tree stem and for displacing said rods forcibly from said lopping position to said retracted position to wipe the rods free of branches and the like on movement through said interior surface.