Abstract A speed control arrangement for electrically operated power tools in which an electronic control circuit within the housing of the tool regulates the speed between no-load and full-load operation of the tool, so that the speed is held substantially constant. The rotor of the motor within the tool is mounted in combination with bevel gears so as to form an angle polishing machine for portable applications. A terminal block mounted within the handle of the portable tool interconnects the wiring between the motor and the electronic controlling circuit. The electronic circuit provides for the operation of the tool from a single-phase utility outlet, and will disconnect the motor from the line when the maximum allowable speed is exceeded.
The motor speed control arrangement as defined in claim 1 including bearing means within the housing for mounting rotatably the rotor of said motor; cooling impeller means mounted on said rotor and rotating therewith for cooling said motor; and output driving linkage means connected to said rotor for driving a load.
Claim 2
Dependent Claim
50 words
The motor speed control arrangement as defined in claim 2 wherein said output linkage means comprises a bevel pinion mounted on said rotor; and a bevel gear in mesh with said bevel pinion, whereby the output axis of speed rotation is perpendicular to the axis of rotation of said rotor.
Claim 3
Dependent Claim
42 words
The motor speed control arrangement as defined in claim 3 including an output shaft driven by said bevel gear and having a threaded portion for threadably receiving a polishing disc, whereby said motor speed control arrangement is operable as an angle polisher.