Hole saw with modified pilot and plug biasing

Abstract

A hole saw includes a mandrel having a central pilot drill bit having a tapered shank to facilitate removal of the plug and an annular cutting saw blade. A helical spring is preferred coaxially mounted between the saw blade and the pilot. The spring biases the plug as the hole is being cut and automatically ejects the plug from the saw. According to a presently preferred embodiment, the spring is a conically tapered helical compression spring. Additional embodiments of modified pilots are also provided wherein the pilot is stepped, fluted, bulged, stepped and fluted, tapered and bulged, tapered with a fluted bulge, and tapered with a fluted rectangular section. The hole saw of the invention is inexpensive to manufacture and easy to use. Depending on the choice of pilot and the material cut, the plug will automatically eject from the saw or will eject after tapping the saw.

Dependencies are inferred from the claim text.