Abstract: Protection device adapted for use with a vertical blade cutter comprising a cutting blade. The device comprises a moveable plate for covering the blade and protecting against accidental contact with the blade. The moveable plate is adapted to be retracted during cutting and is further adapted to be otherwise lowered in front of the blade. A bar is provided which is adapted to slide in a guide adapted to be attached to the cutter. The moveable plate is mounted on the bar. A plate support is journaled onto the guide. A rotatable wheel is attached to the plate support. The rotatable wheel, when brought into contact with the bar while rotating, is adapted to raise the bar and moveable plate and whereas disengagement of the wheel from the bar causes the moveable plate to be lowered in front of the blade by virtue of its own weight and that of the plate.