Patent attributes
The present invention relates to an improved hole-saw assembly and in particular, to a mandrel engageable by a drill and including at least one locking ring or annulus that allows for the base of two hole-saws of different diameter to be quickly and easily mountable and demountable from the mandrel. The hole-saw assembly includes a first hole-saw having a base that includes a pair of drive-pins extending outwardly therefrom and a pair of apertures for insertion therethrough of the drive pins of a second hole-saw. The drive pin pairs are then inserted through corresponding apertures in the mandrel to engage an annulus coupled to the mandrel. The present invention provides for each drive pin to be engaged by the annulus despite the difference in longitudinal length of the drive pins beyond the base of the first hole-saw. The hole-saws are snap-fit within the annulus and may be disengaged by simply rotating the annulus to a second position. A further embodiment of the present invention further allows one to insert the hole-saws into any one of the mandrel insertion points without being concerned about whether it contains the correct engaging means or not. A still further embodiment of the invention prevents slight longitudinal movement which is known to occur when the hole-saws are coupled to the mandrel.
