Patent attributes
The present invention relates to a hole-saw assembly includes a hole-saw having at one end a plurality of cutting teeth and with a boss attached to the hole-saw at the other end two shafts. The assembly includes a mandrel coaxially aligned with said hole-saw and including a body having two bores there through coaxially aligned with said shafts. An annulus located on top of the body is coaxially aligned with said mandrel and hole saw and includes two holes, the annulus rotatable around its longitudinal axis from a first to a second position. In the first position the annulus holes are aligned with the bores and shafts allowing the shafts to be freely insertable and removable and in the second position the holes are misaligned to lock the shafts to the annulus. The mandrel further includes a pair of driving pins adapted to engage driving apertures found in hole-saws especially larger ones. Typically the driving pins may be biased to enable the assembly to be used even with those hole-saws that do not include driving apertures and that also enables easier assembly of the device. A compressible O-ring may further facilitate the operation of the assembly. This device avoids the problem of thread stripping. The invention further provides for a boss that can be used with larger hole-saws and includes notches that accommodate driving pains extending on the side of the boss and where appropriate into the driving apertures.
