The present invention relates to an improved hole saw boss ( 10 ) and in particular, to a boss including a threaded member ( 12 ) adapted to accommodate two hole saws of the same or different bore thread diameters. The present invention allows for a pre-existing aperture ( 22 ) in a work piece to be simply enlarged. This is useful if a new lock mechanism is being installed in a door with a pre-existing aperture where the lock mechanism requires a larger aperture than that which was in existence. Currently the aperture has to be enlarged by manual handwork since there is no centre-point to which a pilot drill may be enlarged. The threaded bore diameters of the present invention correspond with the commonly available hole saw threaded bore diameters. The present invention therefore provides the public with device for enlarging apertures which is simply, cost effective and can be used with currently available hole saws.
1. An improved hole saw boss including:
a base member having at least one notch;
a first threaded member extending outwardly from said base member and adapted to accommodate a threaded bore of a first hole saw, and a second threaded member extending outwardly from said first threaded member and adapted to accommodate a threaded bore of a second hole saw, said second threaded member being of a stepped down diameter to accommodate a hole saw having a threaded bore diameter smaller than the first hole saw; and
at least one drive pin, said drive pin configured to engage both said at least one notch on said base member and an existing aperture on at least one of said hole saws, said drive pins configured to prevent over-tightening of said hole saws on the threaded members.
2. An improved hole saw boss of claim 1 wherein said at least one drive pin is magnetised to restrain said drive pin within said aperture on said hole saw.
3. An improved hole saw boss of claim 1 wherein at least one threaded member is of a length capable of accommodating more than one hole saw of different cutting diameters.
4. An improved hole saw boss of claim 1 wherein said base member and said threaded member include a central aperture adapted to allow a drill bit to fit there through.
5. An improved hole saw boss of claim 1 wherein said boss includes a connection means which is configured to engage a mandrel.