Hand held drill assembly - is fitted with spirit level to facilitate drilling of holes with axes horizontal or vertical

摘要

It is difficult to drill holes with their axes truly vertical or horizontal with a hand-drill. This difficulty can be overcome by fitting the drill with one or possibly two spirit levels which will indicate to the operator that the drill is being held in the correct attitude. The spirit levels may be embodied in the drill or they may be in the form of an attachment. The spirit levels may also be used with hand held tools using other accessories such as circular saws in order to ensure that the cut is at the correct angle.