Title of Invention

A BRUSH ASSEMBLY OF AN ELECTRIC MACHINE

Abstract

A brush assembly of an electric machine comprising a base plate on whjch a pJuraJjty of brush holders are mounte~ the base plate havjng a central hole for receiving the commutator, characterized in that each holder is provided with first and second side slots, the second side slot receiving a spring and being closed at the commutator end, each holder receiving a brush with its connecting lead seated in the first side slot, each first side slot being open at the commutator end and closed at its other end, whereby the brus.h is. enabled to be utilised, on the , commutator, up to a point close to the connecting lead.

Full Text

This invention relates to a brush assembly of an electric machine, more particularly, though not exclusively, a brush assembly for automotive starter motors. In the known automotive starter motor, brushes in contact with the commutator of the motor wear off during use. However, the brushes are not utilised to the extent that they could, because the connecting leads of the brushes interfere with the brush box and prevent the brushes from protruding farther out of the holders. It is therefore the principal object of this invention to propose a brush assembly as aforesaid which permits the brushes to protrude farther beyond the holders than possible in the conventional design. The invention proposed herein thus enhances the life of brushes to the extent of full use of the brushes up to the point of connection of their connecting leads, resulting in considerable saving of brush material and greater economy. The brush assembly for an electric machine, according to this invention, comprises a base plate on which a plurality of brush holders are mounted, the base plate having a central hole for receiving the commutator, each holder being provided with first and second side slots, the second side slot receiving a spring and being closed at the commutator end, each holder receiving a brush with its connecting lead seated in the first side slot, each first side slot being open at the commutator end and closed at its other end, whereby the brush is enabled to -- ; on the commutator, up to a point close to the connecting lead. This invention will now be described with reference to the accompanying drawings which illustrate by way of example, and not by way of limitation, one of possible embodiments of the brush assembly proposed herein, wherein Fig. 1 illustrates a three dimensional view of the proposed brush assembly Fig. 2 illustrates the unusable length of the brush in the known assembly Fig. 3 illustrates the unusable length of the brush in the case of this invention The brush assembly such as, in an automotive starter motor comprises a base plate B on which a plurality of brush holders H are mounted. The base plate B has a central hole A for receiving the commutator of the said starter motor. Each holder H is provided with first and second side slots S1 and S2. The second side slot S2 receives a spring T for retaining the brush B in position within the holder H and applying pressure on the brush.. The side slot S2 is closed at the commutator end C. Each holder H receives a brush B with its connecting lead L seated in the first side slot SI. In the known brush assembly, the side slot which receives the brush and connecting lead is closed at the commutator end C. This construction restricts the movement of the brush beyond the point of connection of the brush to the connecting lead, since the movement of the said lead (and therefore of the brush) would be restrained by the connecting lead fouling against the closed end of the said side slot. On the other hand, in this invention, the side slot S1 is open at the commutator end C whereby the movement of the brush towards the commutator is not restrained by the connecting lead and the brush is enabled to move out farther than the brush in the known brush assembly and thus be utilised up to a point close to the connecting lead (Fig. 3) The terms and expressions herein are of description and not of limitation, since the brush assembly proposed herein is not confined to the embodiment described and illustrated, but it is understood that various other embodiments are possible without departing from the scope and ambit of this invention We Claim: 1. A brush assembly of an electric machine comprising a base plate on which a plurality of brush holders are mounted, the base plate having a central hole for receiving the commutator, each holder being provided with first and second side slots, the second side slot receiving a spring and being closed at the commutator end, each holder receiving a brush with its connecting lead seated in the first side slot, each first side slot being open at the commutator end and closed at its other end, whereby the brush is enabled to be utilised, on the commutator, up to a point close to the connecting lead. 2. A brush assembly as claimed in Claim 1 wherein the second side slot which is closed at the commutator end, is open at its other end. 3. A brush assembly of an electric machine substantially as herein described with reference to, and as illustrated in, the accompanying drawings.

Documents:

0480-che-2005 claims-duplicate.pdf

0480-che-2005 description (complete)-duplicate.pdf

0480-che-2005 drawings-duplicate.pdf

480-CHE-2005 ABSTRACT.pdf

480-CHE-2005 CORRESPONDENCE OTHERS.pdf

480-CHE-2005 CORRESPONDENCE PO.pdf

480-CHE-2005 FORM 18.pdf

480-che-2005-claims.pdf

480-che-2005-correspondnece-others.pdf

480-che-2005-description(complete).pdf

480-che-2005-drawings.pdf

480-che-2005-form 1.pdf

480-che-2005-form 26.pdf