Abstract: A safety blade for a powered rotary lawn mower and method of making same. A layer of high strength fabric of an organic polymer extends throughout the blade. A metallic bar is positioned primarily in the central portion of the blade. The fabric and bar are bonded together and encapsulated in a elastomeric material containing fibers of an organic polymer. The blade is formed so that the outer end portions are provided with cutting edges with the fabric intersecting the cutting edges.

Abstract: A safety cutter blade for a rotary trimmer. The blade has a circular hub formed with a central opening for mounting the blade on the drive shaft of a rotary trimmer. An annulus is made integral with and coplanar with the hub. A plurality of cutting teeth are formed integrally with the annulus at its periphery. Each tooth is provided with a swept convex cutting edge and a straight cutting edge on opposite sides thereof. The convex cutting edges constitute a set of negative cutting edges which force severed foliage away from the center of the blade while the straight cutting edges constitute a second set of cutting edges which are adapted to cutting short grass. Each of these sets of cutting edges is adapted to be effective when they are the leading edges of the teeth of the cutter blade which is determined by the direction of rotation of the trimmer drive shaft and the position of the blade relative thereto.

Abstract: A safety cutter blade for a rotary trimmer. The blade has a hub formed with a central opening for mounting it on the drive shaft of a rotary trimmer. Three equally angularly spaced cutting blades are formed integrally with the hub and extend outwardly from said hub. Each blade is formed with a convex rearwardly swept cutting edge which is tangential to the hub on one side of the cutting blade and a short straight forwardly swept cutting edge on the other side of each cutting blade. Either of these cutting edges is adapted to be the leading, or effective edge depending on the orientation of the blade on the drive shaft and the direction of rotation of the trimmer shaft. The safety blade is made of an elastomer reinforced with plastic fibers. A layer of coarse fabric made of threads of an organic polymer is embedded in the elastomer and intersects the cutting edges of the cutting blades.