Abstract: 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.

Abstract: A switch for controlling electric D.C., especially for a power tool held by hand during operation, for heavy duty work, preferably from an automobile battery, of 8 to 40 volts and sufficient amperage for at least about 180 watt-input into the idling tool motor, comprises a base mountable on the motor rearwall, fixed contactors on the base, a supporting member bearing shiftable contactor elements, a first engaging member on the base, another engaging member on the supporting member and pivotably engaged by the first engaging member, a resilient organ urging the two engaging members into engagement, and preferably enhancing contact pressure between the fixed and shiftable contactors when a manual actuator has pivoted the supporting member from neutral into an activating position. A restoring spring can return the supporting member automatically to neutral.

Abstract: An electric rotary power tool apparatus is adapted for loosening jammed or seized automobile wheel nuts or bolts and holdable by hand during operation. It comprises(1) an electric motor laid out to be driven by an electric direct current having an operational voltage of at least 8 to 30 volts and at least 20 up to 60 amperes, and comprising a stator, a rotor, first and second pole means, and a driving shaft bearing said rotor and having a rotary axis, the speed of said motor, at a nominal voltage of 12 to 24 volts ranging from 8000 to 30000 r.p.m. under load;(2) a casing in which the motor is housed;(3) an on-off and reversing switch;(4) tool socket means being adapted for receiving a socket tool therein and comprising a driven shaft, the speed under load of which driven shaft is in the range of from 1200 to 4000 r.p.m.

Abstract: An electric rotary power tool apparatus is adapted for loosening jammed or seized automobile wheel nuts or bolts and holdable by hand during operation. It comprises(1) an electric motor laid out to be driven by an electric direct current having an operational voltage of at least 8 to 30 volts and at least 20 up to 60 amperes, and comprising a stator, a rotor, first and second poles, and a driving shaft bearing said rotor and having a rotary axis, the speed of said motor, at a nominal voltage of 12 to 24 volts ranging from 8000 to 30000 r.p.m. under load;(2) a casing in which the motor is housed;(3) an on-off and reversing switch;(4) a tool socket being adapted for receiving a socket tool therein and comprising a driven shaft, the speed under load of which driven shaft is in the range of from 1200 to 4000 r.p.m.