| 摘要 |
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. |
