Abstract: Sharpening the cutting edge of a chipper knife having a chip-breaking shoulder in its underside remote from the cutting edge apex which is integral with the chipper knife is effected by removing a layer of material of uniform thickness from the underside of the cutting edge and thereby removing the bluntness of a dulled cutting edge and forming a resharpened cutting edge having the same wedge angle as the cutting edge prior to resharpening.

Abstract: A log chipper is provided for allowing a lower horsepower rated motor to drive the chipper. Peak power demand is reduced by cutting shorter chips from large diameter logs, while the length of chips cut from logs of small and medium diameter continues to be of standard specified length, the length of chips cut from large diameter logs only being shortened. The feed rate for large diameter logs is reduced and will therefore result in a reduction of peak power demand achieved by the use of large diameter log positioning means. A first version of the large diameter log positioning means involves the placement of a raised platform on the wear plate where the outer perimeter of the large diameter log would otherwise contact the wear plate. A second version of the positioning means involves raising the heel of the knife clamp at a point where a portion of the outer perimeter of a large diameter log contacts the heel of the clamp.

Abstract: A chipper apparatus including a rotating disc with one or more knife assemblies mounted on the disc operable to produce wood chips under the cutting action of the knives. Each knife comprises an elongate knife body bounded by opposed cutting edges. The cutting edge further includes a contact surface for breaking apart and deflecting chips. The knife assembly includes interlocking keys for adjustable positioning of the knife in relation to a counter knife having multiple key recesses. The adjustable positioning of the knife permits the complete resharpening of the knife cutting edges.

Abstract: Attitude control mechanism for a flexible bag component of a composite pneumatic chamber including a fixed section over which an inturned portion of a flexible bag pneumatic chamber section rolls includes a cantilever bag attitude control stem having its root anchored in a mounting closing the end of the flexible bag remote from the rigid pneumatic chamber section and extends through a central guide aperture of at least one frame mounted within the rigid pneumatic chamber section for substantially linear reciprocation guidance so as to prevent appreciable buckling of the flexible bag as it is contracted axially by movement of the mounting carrying the stem toward the rigid pneumatic chamber section.