Abstract: Disclosed is a digger attachment for a tractor including a frame having at one end of a frame arm a three-point mount for securing the digger to the tractor. The opposite end of the frame arm supports an auger for pivotal movement about a transverse axis. Attached to the head of the auger is a shaft which extends through a bracket mounted on the frame arm. Coil springs are provided about the shaft on opposite sides of the bracket with the opposite ends of the springs butting against nuts threaded on the shaft. To utilize the digger, the nuts on the opposite ends of the shaft are threaded such that the springs displace the shaft in a manner displacing the auger about its transverse pivotal axis such that its rotational axis is slightly rearwardly inclined relative to a vertical through the auger's pivot. That is, the nuts are respectively threaded and unthreaded to achieve the desired inclination of the auger with the spring forces acting on the shaft in balance.

Abstract: An air pre-cleaner is provided for use with an internal combustion engine. The pre-cleaner comprises a housing and vanes fixed to the top of the housing for imparting a circular motion to the air entering the housing between the vanes. This circular motion causes the heavy particles in the air to be projected away from the axis of the housing because of the centrifugal force on the particles caused by the circular motion. A tube means is positioned in the housing and a separator having a plurality of louvers is positioned in the housing between the wall of the housing and the tube. The heavy particles pass through the openings in the louvers and fall from the separator means under the influence of gravity and exit from the housing. The air with the heavy particles removed therefrom then passes through the tube and into the engine. A control mechanism is positioned in the housing between the separator and the exit for controlling the flow of air through the exit towards the separator.