Brush holder for an electric motor

Brush holder for an electrical motor having a commutator, comprising:

• an electrically insulating support structure having a opening for receiving the commutator, around which retaining and guiding cages are fixed, each cage having, translatably mounted therein, a respective positive or negative brush, one end of which is intended to bear during operation against the commutator;
• the support structure comprising a molded-plastic body incorporating at least one first and one second conducting element intended to be connected to the positive and negative terminals, respectively, of an external supply-voltage source and connected to the positive and negative brush or brushes, respectively, via a first and a second connection path so as to allow the brushes to be coupled to said voltage source;
• a discontinuity being provided in one of said connection paths;
• and
• a resiliently deformable and electrically conducting strip being connected mechanically and electrically across said discontinuity with a substantially permanent connection at one end and with a heat-meltable connection at the other end and with a resilient pre-load tending to break the connection at said other end;
• wherein the brush holder further comprises a voltage drop resistor for operation of the motor at a reduced speed, having one terminal connected to said first conducting element via a thermally and electrically conducting connection.