Bias torque for elevator hoist drive to avoid rollback, rollforward
US5531294A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 1994 |
| Grant date | Jul 2, 1996 |
| Priority date | — |
| Expiry date | Sep 28, 2014 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB66B1/28
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
Armature current I.sub.ARM is measured at full load and empty load. These two values are used to calculate a pre-torque armature current gain (MBIAS) and an overbalance correction is included in calculation of an elevator pre-torque armature current I.sub.ARM to compensate for an erroneous overbalance value for providing an armature current I.sub.ARM which does not cause rollback or rollforward of an elevator hoist motor. Samples of elevator car load and armature current I.sub.ARM are taken after the elevator brake is lifted, with the car at zero velocity, over a number of runs for continually recalibrating the pre-torque armature current gain (MBIAS) and offset, thereby compensating for any drift in performance of the loadweighing system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.