Abstract: In one embodiment, a method of sharpening reel blades on a lawnmower reel includes positioning a grinding wheel in contact with the reel, rotating the grinding wheel about an axis of rotation, linearly translating the grinding wheel along a longitudinal path. and rotating the reel about its longitudinal axis. The axis of rotation of the grinding wheel is transverse to a longitudinal axis of the reel.

Abstract: A ring cutter that cuts chips with a ring of knives. Two carrier rings enclose a collar of knife packets. Each knife packet includes a knife clamped between a knife carrier a clamping plate with a cutting edge of the knife pointing to the inside of the ring. Fastening screws are threaded through a borehole in the clamping plate and an opening in the knife and are screwed into a threaded borehole in the knife carrier. One of the fastening screws is configured as an alignment pin.

Abstract: A knife ring machining tool for machining chips, with a knife ring comprising a crown of knife packets as well as two carrier rings carrying the packets, which rings are arranged on the ends of the knife packets. Each knife packet includes a knife that is inclined against the radial direction and whose cutting edge faces inward, with a rotor arranged coaxially with the knife ring and surrounded by the latter. The rotor includes a plurality of rotor blades that carry strip-shaped cleaving knives on the outer ends, which knives for their part run parallel to the rotor axis and extend over the width of the rotor. Each cleaving knife is fastened by screws to the associated rotor blade, while each screw connection comprises a wedge element that tapers outward in radial direction in a wedge shape, as viewed in a section vertical to the rotor axis.