Brush wear indicator for a dynamoelectric machine

DETAILED DESCRIPTION In the preferred embodiments of the invention disclosed herein, a brush wear indicator for a dynamoelectric machine is provided for signalling the occurrence of a predetermined degree of brush wear.
The indicator mechanism includes an electromechanical transducer that is operably connected between a negator spring of a relatively conventional brush holder assembly and a movable electrical contact that forms part of a signal circuit.
A variety of bracket structures are disclosed for supporting a fixed electrical contact in the path of movement of the movable contact, and resilient biasing means are connected to the transducer in order to bias the movable contact away from the fixed contact.
Signal circuit means are connected in series with the fixed and movable contacts so that when the negator spring winds up responsive to the occurrence of a predetermined degree of brush wear, it causes the transducer to move the movable contact into engagement with the fixed contact and thereby energize the signal circuit to indicate a given degree of brush wear.