1. Field of the Invention
The present invention relates to blades for grass mowers and agricultural implements, and, particularly to the improved two piece construction of a peripheral blade.
2. Discussion of the Prior Art
U.S. Pat. No. 5,375,400 to John A. Darden teaches a peripheral mower blade that is designed to cut and mulch grass at high volume. The blade is so designed to reduce back drag and require less horsepower. Such peripheral blades offer less chance that objects will be thrown out from under the mower deck they are mounted on, nor will they come apart creating a dangerous environment for those who are around the mower. In the construction discussed by Darden in '400, the blade is one piece. At the time, Darden taught that a one piece blade made manufacture of the blade less expensive and made the blade more durable.
However, several drawbacks have been discovered with respect to the one piece peripheral mower blade. Such blades have been found time consuming and difficult to change. Since peripheral mower blades are mounted on a horizontal rotary shaft in a series containing several blades, all of the interim blades must be removed in order to replace a worn or damaged blade that is toward the center of the shaft. The one piece blades also require a series of spacers on the shaft separating the blades, and these spacers also must be dealt with when replacing or arranging the one piece peripheral blades on the shaft.
Thus, a need exists to improve peripheral mower blades to make them easier to install, especially when a blade on the center of the horizontal rotary shaft is damaged or worn. A two piece blade could be considered, but, before now, providing a two piece blade has been avoided and not seriously considered because of the belief that such blades would provide a weak structure and could break off of the shaft and present a danger of being slung outward from a mower.