Abstract: A contaminant sorting device for sorting contaminant material, such as metal and rocks, from processing materials, such as wood chips, comprising a housing having internal walls formed of a surface of revolution into which housing is fed processing material at the upper portion thereof, an impeller disposed in the housing for receiving processing material and propelling it radially outwardly against the inner surfaces of the housing walls, a plurality of vibration sensing devices disposed around the walls of the housing for sensing vibrations due to impingement of the processing material on the walls, an electrical circuit for distinguishing between signals generated in response to impact of the processing material from response to impact of contaminant material, a series of trap doors each associated with a corresponding vibration sensing device and disposed downstream in the material flow path for diverting from the normal flow path a portion of processing material containing contaminant material.

Abstract: A contaminant sorting device for sorting contaminant material such as metal and rocks from process materials such as wood chips which are intended to be subsequently processed, comprises a material receiving surface upon which a layer of material is deposited which material contains both contaminant and process material, an impact sensing device for sensing vibrations of the material receiving surface upon impact of the material thereon, an electronic circuit for distinguishing between signals generated by impact of contaminant material from signals generated by impact of process material and for providing an output signal in response to receipt of a contaminant material signal, a flow diverting plate downstream from the material receiving surface which is activated by the signal produced in response to impact of the contaminant material so that the normal flow path of the layer of material is interrupted so as to divert that portion of material containing contaminant material to a separate receptacle, and ti

Abstract: A saw tooth insert, for securing to a saw plate, comprises a front cutting surface containing two adjacent grooves extending for substantially the entire height of the cutting face and substantially radially outward from the rotational axis of the saw plate. The lower portions of the grooves end on opposite sides of the saw plate and the upper portions of the grooves form a central cutting edge between them and external cutting edges on each side of the cutting face where the grooves meet the side surfaces of the insert.