Patent attributes
The invention features an elongated blade having at least one first tooth near a first end extending in one direction and at least one second tooth near a second end extending in the opposite direction. The body of the blade can be a generally rectangular plate. There can be at least two first and second teeth. The blade can include four corners, wherein at the first end the first teeth are formed in the first edge and at the second end the second teeth are formed in the second edge. Edges of the blade can be formed without teeth near two corners and can be sharpened or not. The teeth may extend different distances from the blade. The blade cuts into a surface. In one application, the blade is used for edging or trenching and is rotated generally vertically so as to penetrate the ground and any material on or in the ground such as grass, sod, turf, leaves, thatch and the like. The invention also features devices used to power a shaft on which one or more of the blades are mounted, such as edging or trenching machines.