Multi-speed motor
US5485049A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 1994 |
| Grant date | Jan 16, 1996 |
| Priority date | — |
| Expiry date | May 25, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02K2213/03
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A multi-speed, direct current motor (120) incorporates a high speed (24) brush disposed between the low speed (22) and the common ground (26) brushes and having a non-arcuate end face (25) which, unlike the conventional arcuate brush end face (23,27), is not subject to speed-drift erosion. The non-arcuate end face (25) is configured of two offset surfaces (55,65 & 57,67) which intersect to provide a line of contact (43) between the end face (25) of the high speed brush (24) and the commutator (40) which is displaced from the center line of the high speed brush (24) in a direction counter to the direction of rotation of the motor, that is toward the leading edge (21) of the brush (24). The intersecting surfaces (55,65 & 57,67) may comprise either flat planar surfaces or contoured surfaces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.