DRAAGBARE BOOREENHEID.

摘要

A portable magnetic drill unit having a work surface engaging base formed as an electromagnet and a spring biased bearing ball thereon for elevating the rear end of the base slightly above the work surface to enable the unit to be easily moved along the work surface to the desired location for drilling a hole. The strength of the spring is correlated to the weight of the drill unit and the strength of the electromagnet such as to support the unit in a slightly elevated position when the electromagnet is de-energized and to compress when the electromagnet is energized so as to allow the bottom face of the base to contact and magnetically adhere to the support surface.