| 摘要 |
An indicator is provided in a dynamoelectric machine such as a DC electric motor wherein brushes are provided in brush holders to cooperate with a rotatable electrical conductor in the machine, for example, slip rings or a commutator. The indicator gives an indication when a brush has worn to a point where it should be replaced, and then an alarm sounds or a light is illuminated. The brush wear indicator includes an indicator contact which is electrically connected to the indicator means and it is insulated from but mounted to move in accordance with the brush wear movement. The contact is provided on the end of an electrical conductor which is embedded in the rear axial end of the brush so that the indicator contact will become exposed and the insulation covering it will be worn away upon sufficient brush wear. This completes an electrical circuit between the indicator contact and the commutator to thus provide an indication at the indicator means.
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