Commutator

1. A commutator comprising an electrically non-conductive base and a plurality of electrically conducting segments supported by the base, each segment comprising:

a first electrically conductive inner layer provided on the base,

a second electrically conductive outer layer fixed to the inner layer, the inner and outer layers having opposing surfaces which abut each other, and

an unfilled opening for receiving flux and/or air during the fixing of the outer layer to the inner layer provided in at least one of the opposing surfaces.

2. The commutator of claim 1 , wherein the opening is a bottomed recess.

3. The commutator of claim 1 , wherein the opening is provided in the opposing outer surface of the inner layer.

4. The commutator of claim 1 , wherein the opening is provided in the opposing inner surface of the outer layer.

5. The commutator of claim 1 , wherein the opening is a pressed recess.

6. The commutator of claim 1 , further comprising an anchor which anchors the inner layer to the base.

7. The commutator of claim 6 , wherein the anchor is formed from a portion of the inner layer.

8. The commutator of claim 6 , wherein the anchor is formed from material pressed from the inner layer when forming the opening.

9. The commutator of claim 6 , wherein the anchor has an inverted V-shape.

10. The commutator of claim 6 , wherein the anchor is spaced from an edge of the inner layer.

11. The commutator of claim 1 , wherein the inner layer of each segment includes a second opening in which is received a portion of the base.

12. The commutator of claim 11 , wherein the second opening is an aperture which extends through the inner layer.

13. The commutator of claim 1 , wherein the segment includes a tang formed from the inner layer.

14. The commutator of claim 1 , wherein the inner layer is metal, the outer layer is graphite, and the base is a resin.

15. The commutator of claim 1 , wherein the electrically non-conductive base includes a plurality of pre-formed notches for receiving a cutting device and preventing or limiting chipping during segmentation.

16. The commutator of claim 1 , wherein the commutator is planar.

17. The commutator of claim 1 , wherein there are sixteen electrically conducting segments.

18. A DC electric motor comprising: a motor housing, a stator in the housing, a rotor having a shaft rotatably mounted in the housing, a rotor core fixedly provided on the shaft and juxtaposed to the stator, a commutator as defined in claim 1 fixedly mounted on the shaft, and brush gear in electrical contact with the commutator.

19. A commutator comprising an electrically non-conductive base and a plurality of electrically conducting segments supported by the base, each segment comprising:

a first electrically conductive inner layer provided on the base, the inner layer of each segment including an aperture which extends through the inner layer in which is received a portion of the base;

a second electrically conductive outer layer fixed to the inner layer, the inner and outer layers having opposing surfaces which abut each other;

an unfilled opening for receiving flux and/or air during the fixing of the outer layer to the inner layer provided in at least one of the opposing surfaces; and

an anchor formed from material pressed from the inner layer when forming the opening which anchors the inner layer to the base;

wherein the electrically non-conductive base includes a plurality of pre-formed notches for receiving a cutting device and preventing or limiting chipping during segmentation.