Abstract: A floor treating machine includes an electric motor, batteries free from leakage and mounted on a motor deck for supplying a current to the electric motor, a rotary shaft extending vertically and driven by the electric motor, and a floor treating device, such as a brush or sponge, detachably attached to a lower end of the rotary shaft to be rotatable therewith. The floor treating device contacts a floor and supports the machine during a floor treating operation. The electric motor is connected to the batteries through an on/off switch. The floor treating machine further includes a rotating rate varying device operable upon start of the electric motor for gradually increasing a rotating rate of the electric motor to reach a predetermined operational rotating rate after lapse of a predetermined time.

Abstract: An electric floor cleaner is of the type arranged to drive a three-phase motor, whose rated voltage is substantially equal to a voltage obtained by voltage doubling and rectifying a single-phase commercial power line and then by converting a voltage doubled d.c. voltage into three-phase a.c. by an inverter. The voltage and frequency of the three-phase a.c. output from the inverter are controlled for a predetermined period of time after a power switch is put into a turned on state from a turned off state. It is therefore possible to reduce the starting current to a small value enabling the use of a larger rated output motor than a motor in a conventional system within an allowable current limit of a commercial power line.