Shape memory actuator
US4979672A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1990 |
| Grant date | Dec 25, 1990 |
| Priority date | — |
| Expiry date | Apr 18, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2061/0122
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A shape memory actuator for controlling the position of a control member, such as a damper plate in a duct, the actuator including first and second shape memory elements each having an austenite phase transition temperature above which each element assumes a predetermined memory shape and a lower phase which forms when said element is stretched from the predetermined memory shape, the first and second elements being connected to move the control member in different directions when one or the other of the elements are heated to a temperature above its austenite phase transition temperature and an electrical circuit for selectively raising the temperature of one or the other of the elements. The control member may be held in a position between full open and full closed by holding mechanisms which connect the actuator to the control member. The holding mechanisms include a visco elastic mechanism, a positive interlock mechanism that is released by a shape memory element, or a magnetic member formed of alternately arranged magnetic poles. A number of connectors are disclosed for connecting the SMA members to the dampers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.