Variable force linear actuator
US4698608A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 29, 1986 |
| Grant date | Oct 6, 1987 |
| Priority date | — |
| Expiry date | Apr 29, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F7/066
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A linear electromechanical actuator having a variable drive force. The actuator includes a moving coil which moves along a stroke path in response to an input current. A magnetic circuit provides a magnetic flux through which the coil is driven. The flux density along the stroke path is non-uniform, with a higher flux density being present only in that region of the stroke path where a higher actuator drive force is required. Thus, less expensive magnetic material can be used. Since the overall flux density in the magnetic circuit is reduced, the dimensions of the soft iron elements of the magnetic circuit can be reduced without magnetic saturation so as to further reduce construction costs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.