The present invention relates to a power tool with an electric motor.
With power tools operated using commutator motors (universal or direct-current motors), current is transferred to an armature winding via a commutator. To this end, (carbon) commutator brushes glide over the collector (contact roller) of the commutator. The collector is usually laminated, is non-rotatably mounted on an armature shaft, and is connected with the armature winding in an electrically conductive manner. During operation of the power tool, the commutator brushes undergo frictional wear due to the sliding motion. With high-quality power tools in particular, worn commutator brushes may be replaced with new commutator brushes. To accomplish this, a spring that presses the worn commutator brush against the collector of the commutator must first be displaced, i.e., lifted, usually.
To ensure easy access to the spring and the worn commutator brush, it is known to integrate a brush cover in the housing above the commutator brush, so that the power tool need not be fully disassembled in order to replace the commutator brush. An auxiliary tool that is typically filigree and hook-shaped is required to displace the spring. An auxiliary tool of this type is often a piece of wire, cable, or the like that has been bent into the necessary shape. If material of this type is unavailable for manufacturing the auxiliary tool, operators often try to remove the spring using other, unsuitable tools, such as a screwdriver, which often results in damage to the power tool.
USPTO Backgrounds
USPTO Backgrounds