A blade protection cover coupled to a blade of a lawn mower apparatus includes a first cover for covering one face of the blade and two second covers connected to the first cover. The two second covers cover two edges of the blade in a width direction of the blade. Two guides are disposed on inner faces of the two second covers. The two guides are configured to guide the blade protection cover to slide along the two edges in the width direction of the blade.

A cutting system for a header of an agricultural machine includes a knife guard having a plurality of guards that are spaced apart by a guard pitch, and a knife section that is configured to move with respect to the knife guard for cutting crop material. The knife section includes a plurality of knives that are spaced apart by a knife pitch. The guard pitch is neither equal to nor is a whole number multiple of the knife pitch.

A cutting system for a header of an agricultural machine includes a knife guard having a plurality of guards that are spaced apart by a guard pitch, and a knife section that is configured to move with respect to the knife guard for cutting crop material. The knife section includes a plurality of knives that are spaced apart by a knife pitch. The guard pitch is neither equal to nor is a whole number multiple of the knife pitch.

A cutter assembly includes a knife guard holder to be removably connected to a cutter bar, a knife guard and an interface between the knife guard holder and the knife guard. The knife guard may have a knife channel to slidably guide a cutter knife. The interface extends between the knife guard holder and the knife guard to locate and releasably retain the knife guard with respect to the knife guard holder.

A cutter assembly includes a knife guard holder to be removably connected to a cutter bar, a knife guard and an interface between the knife guard holder and the knife guard. The knife guard may have a knife channel to slidably guide a cutter knife. The interface extends between the knife guard holder and the knife guard to locate and releasably retain the knife guard with respect to the knife guard holder.

A system for monitoring a condition of a sickle of a header of an agricultural machine. The system includes a knife guard mounted to the header, a knife section of the sickle that is configured to move either along or with respect to a surface of the knife guard, and a sensor either mounted to the knife guard or another surface of the header for sensing the condition of the knife section.

A system for monitoring a condition of a sickle of a header of an agricultural machine. The system includes a knife guard mounted to the header, a knife section of the sickle that is configured to move either along or with respect to a surface of the knife guard, and a sensor either mounted to the knife guard or another surface of the header for sensing the condition of the knife section.

A sickle guard counter-knife insert includes a pair of counter-knives. Each counter-knife defines a channel for an operable sickle bar between mutually-coupled upper and lower portions. The counter-knives and a connecting crossbar are formed together as an integral unit.

A sickle guard counter-knife insert includes a pair of counter-knives. Each counter-knife defines a channel for an operable sickle bar between mutually-coupled upper and lower portions. The counter-knives and a connecting crossbar are formed together as an integral unit.

An agricultural vehicle includes a chassis and a header carried by the chassis. The header includes a cutterbar with at least one cutting unit. The at least one cutting unit includes a rotary driver; a rotatable disc coupled to the rotary driver; at least one knife mount coupled to a disc surface of the rotatable disc and including a locking portion biased toward the disc surface; and a knife locked in at least one direction by the locking portion, the knife defining at least one cutting edge.