Abstract: A cutter blade for a mower includes a blade base part, a cutting part positioned further outward radially than the blade base part, a descending part formed between the blade base part and the cutting part, and a curved part formed so as to curve upward from the cutting part. The descending part and the curved part have an intersection part at which an end of the descending part in the counter-rotating direction and a radially inner end of the curved part intersect.

Abstract: A cutter blade for a mower is provided with: a blade base part; a cutting part positioned further outward radially than the blade base part; a descending part formed between the blade base part and the cutting part; and a curved part formed so as to curve upward from the cutting part. The descending part and the curved part have an intersection part at which an end of the descending part in the counter-rotating direction and a radially inner end of the curved part intersect.

Abstract: A lawn mower includes a cutter blade that is an elongated member extending in opposite horizontal directions with respect to a vertical rotation shaft. The cutter blade includes, on each of its longitudinally opposite end portions, a blade section formed along the front edge, in a rotating direction of the cutter blade, of the end portion, and an air lift section extending from the front edge while curving rearward and upward. The air lift section has a vertical downward wing formed integrally thereon and extending downward via a bent section that is bent downward from at least a rear half portion, in the rotating direction, of an outer peripheral edge of the air lift section. The bent section has a radius set to gradually increase as the air lift section curves rearward and upward in the rotating direction.

Abstract: A lawn mower includes: a rotation shaft extending vertically in a downwardly-opening housing; and a cutter blade rotatably mounted on the rotation shaft. The cutter blade is an elongated member extending in opposite horizontal directions and having two bent sections formed on respective ones of its longitudinally opposite end portions. The two bent sections are bent in opposite directions as viewed in the axial direction of the rotation shaft. The cutter blade has, on each of the bent sections, a convex cutter blade section formed along a convex edge of the bent section and a concave cutter blade section formed along a concave edge of the bent section. The convex cutter blade section on each of the bent sections has a smaller cutting edge angle than the concave cutter blade section.

Abstract: A lawn mower includes a cutter blade that is an elongated member extending in opposite horizontal directions with respect to a vertical rotation shaft. The cutter blade includes, on each of its longitudinally opposite end portions, a blade section formed along the front edge, in a rotating direction of the cutter blade, of the end portion, and an air lift section extending from the front edge while curving rearward and upward. The air lift section has a vertical downward wing formed integrally thereon and extending downward via a bent section that is bent downward from at least a rear half portion, in the rotating direction, of an outer peripheral edge of the air lift section. The bent section has a radius set to gradually increase as the air lift section curves rearward and upward in the rotating direction.

Abstract: A lawn mower includes: a rotation shaft extending vertically in a downwardly-opening housing; and a cutter blade rotatably mounted on the rotation shaft. The cutter blade is an elongated member extending in opposite horizontal directions and having two bent sections formed on respective ones of its longitudinally opposite end portions. The two bent sections are bent in opposite directions as viewed in the axial direction of the rotation shaft. The cutter blade has, on each of the bent sections, a convex cutter blade section formed along a convex edge of the bent section and a concave cutter blade section formed along a concave edge of the bent section. The convex cutter blade section on each of the bent sections has a smaller cutting edge angle than the concave cutter blade section.

Abstract: An exhaust circulation lawnmower is disclosed in which grass clippings are sent, along with carrier air, from a cutter housing to a grass bag; the grass clippings are held in the grass bag; and the carrier air is returned to the cutter housing as exhaust. A surface area A1 of a grass clippings discharge opening and a surface area A2 of a recirculation opening have a relationship of A2?{1/(1??N)0.5}A1, where A1 is the surface area of the grass clippings discharge opening through which the grass clippings and carrier air are discharged from the cutter housing to the grass bag, A2 is the surface area of the recirculation opening through which the carrier air is recirculated from the grass bag to the cutter housing, N is the number of bends having an angle of ? degrees in the space between the grass clippings discharge opening and the recirculation opening, and ? is a pressure loss coefficient for each of the bends.

Abstract: An exhaust circulation lawnmower is disclosed in which grass clippings are sent, along with carrier air, from a cutter housing to a grass bag; the grass clippings are held in the grass bag; and the carrier air is returned to the cutter housing as exhaust. A surface area A1 of a grass clippings discharge opening and a surface area A2 of a recirculation opening have a relationship of A2?{1/(1??N)0.5}A1, where A1 is the surface area of the grass clippings discharge opening through which the grass clippings and carrier air are discharged from the cutter housing to the grass bag, A2 is the surface area of the recirculation opening through which the carrier air is recirculated from the grass bag to the cutter housing, N is the number of bends having an angle of ? degrees in the space between the grass clippings discharge opening and the recirculation opening, and ? is a pressure loss coefficient for each of the bends.