Electric truck having elevated load potential energy recovery with means to adjust rate of carriage descent
US3947744A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1974 |
| Grant date | Mar 30, 1976 |
| Priority date | — |
| Expiry date | Oct 21, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S320/34
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A lift truck energized from a battery to supply pressurized fluid to elevate a load-supporting carriage has an energy recovery system for converting kinetic energy of the elevated carriage into battery charging current including a fluid motor through which fluid from the lift ram is exhausted when the carriage is descending, an alternator driven by the fluid motor, a rectifier between alternator and battery, a transistor having its emitter-collector circuit in series with the field winding of the alternator, and a rate-of-descent adjusting potentiometer for selectively varying base drive to the transistor to thereby regulate field excitation of the alternator and the regenerative braking of the fluid motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.