Blade assembly for a lawn mower

An attachment system for connecting a blade to a drive shaft of a lawn mower and the drive shaft including a threaded end, the attachment system comprising:

• an adapter coupled to the drive shaft and configured to receive the blade, the adapter including an elongated adapter body, a central bore defined in the adapter body, the central bore receiving the drive shaft, a first projection extending from the adapter body to engage a first aperture of the blade, and
• a second projection extending from the adapter body to engage a second aperture of the blade, the second projection on an opposite side of the central bore from the first projection;
• a fastener threadingly engaged with the threaded end of the drive shaft, wherein the first projection includes a cross-sectional shape that is different from a cross-sectional shape of the second projection, wherein a straight line extends between the first projection, the second projection, and the central bore, the straight line intersects an axis extending in a direction of elongation of the adapter body, and the straight line and the axis are not colinear;
• and
• an insulating member mounted to the adapter, the insulating member comprises an insulating material, the insulating member is in surface contact with the blade when mounted to the adapter, a bottom of the insulating member is provided with a groove, and at least a portion of the adapter is embedded in the groove.

A lawnmower comprising:

• a mower deck;
• a drive shaft projecting from the mower deck, the drive shaft including a threaded end;
• an attachment system suspended below the mower deck, the attachment system including:
• an adapter coupled to the drive shaft,
• an insulating member mounted to the adapter, the insulating member comprising an insulating material, and
• a fastener threadingly engaged with the threaded end of the drive shaft;
• and
• a blade removably coupled between the adapter and the fastener and in surface contact with the insulating member, the blade including:
• a blade body having a first end and a second end opposite the first end,
• a longitudinal axis extending centrally along the blade body and through the first end and the second end, the longitudinal axis extending generally perpendicular to the drive shaft,
• a center opening defined in the blade body, the center opening receiving the drive shaft therethrough, the center opening having a centroid substantially aligned with the longitudinal axis,
• a first aperture defined in the blade body between the center opening and the first end, and
• a second aperture defined in the blade body between the center opening and the second end, the second aperture being a different shape from the first aperture,
• wherein the centroid of the first aperture, the centroid of the second aperture, and the centroid of the center opening form a straight line, and the straight line intersects but is not colinear with the longitudinal axis.