is curved on the ends and straight in the middle the reciprocating blade 106 in this embodiment defines and imaginary tip line with a convex curve along its entire length it should be noted that the present invention is not limited to the embodiments depicted but also includes combinations of the disclosed embodiments such as the stationary blade defining an imaginary tip line created by a concave curved line and the reciprocating blade defining an imaginary tip line created by a convex line the stationary blade defining an imaginary tip line created by straight angled line segments and the reciprocating blade defining an imaginary tip line created by convex line segments on the ends and a straight line portion in the center etc one important consideration to remember when determining the blade shapes of the present invention is that the distance between the tips of the reciprocating blade and the tips of the stationary blade should be increased near the ends thereof as discussed above such increased distances at the ends may be achieved by reducing the tip heights of the end sections of teeth of the reciprocating blade by increasing the tip heights of the end sections of teeth of the stationary blade or by a combination of these tip reductions of the reciprocating blade and these tip elongations of the stationary blade in this manner the tips of the reciprocating blade will not overlap the tips of the stationary blade even as the reciprocating blade moves in its designated arcuate motion the advantages of this invention should now be apparent specifically the various embodiments incorporate a unique design which enables a decrease in the overlap between the reciprocating cutting teeth and the stationary cutting teeth.