Saw teeth for circular saws of the type mounted on a feller head for a tree felling apparatus are known. An example of such saw teeth are of the replaceable type having four sides. The teeth can be rotated when the active cutting tips and edges become dull or worn so that unused ones are presented to the tree.
Saw teeth wear relatively quickly and may become rounded or dull. This may cause increased fuel consumption, decreased productivity, or poor cut quality, or all of them, and may tend to result in a need for maintenance. The outermost cutting tips of the teeth are also susceptible to damage from impact, such as when the teeth strike objects such as rocks and other debris during the felling of trees. This may also lead to a need for maintenance.
Some teeth have carbide wear plates with sharp corners at the cutting tips. These corners may tend to chip or break off easily when striking objects or debris. This may result in a loss of the cutting edge and in a loss of cutting efficiency. Other teeth may have flat plateaus at the cutting tips. These may be more durable but may become rounded or dull faster and may be less efficient at cutting tree fibers.
U.S. Pat. No. 8,430,009 to Micacchi, issued Apr. 30, 2013, describes a saw tooth that includes front cutting tips and secondary trailing cutting tips, provided further rearwardly on the saw tooth. However, these secondary cutting tips are shaped so that the tree fibers that are cut thereby are evacuated in the direction of advance, which creates resistance to the forward motion of the tooth and consequently of the saw. Also, in this saw tooth, cutting tips are only provided over a relatively small portion of the circumference of the saw tooth, namely at the corners thereof.
In view of the above, there is a need in the industry for an improved saw tooth.
An object of the present invention is to provide such a saw tooth.