Electric rotary power tool apparatus holdable by hand during operation, kit comprising the same, and novel switch means therefor

摘要

A power tool apparatus which is hand-holdable during operation serves for facilitating especially heavy duty work, e.g. on a high scaffolding. The apparatus is composed of three building blocks, a central one haivng an elongated enveloping shell and an integral transverse wall dividing the shell into a forward and a rearward compartment. The latter contains a speed-reducing transmission unit and has a motor unit attached to the shell rear end. As a third building block the operator equipped with a kit according to the invention has the choice of several inset units, among them a simple front end wall with an intermediate shaft, and the same end wall and an impact-generating unit on the intermediate shaft, which inset units he can introduce through the open front end of the enveloping shell and exchange them as required without taking apart the transmission unit or detaching the motor unit. A handle can likewise be attached to the central shell unit. Various novel types of switches are also provided for use at the rearward end of the motor and/or with the handle.