Elevator safety device
US4133413A · kind A · utility
9Cited by
3References
5Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jul 25, 1977 |
| Grant date | Jan 9, 1979 |
| Priority date | — |
| Expiry date | Jul 25, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P7/293
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An armature of an electric motor for an elevator car is controllably driven by a three-phase source through a semiconductor converter controlled with a difference between a command and an actual car speed signal. A relay for sensing a ripple current from the converter is serially connected to a tuned filter across the armature. When a break occurs anywhere in a circuit with the motor armature, the sensor relay is deenergized and connects an emergency braking circuit across the armature. Alternatively the sensor relay may be connected via the filter to a reactor connected to the converter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.