Shifter with shape memory alloy and safety
US8117938B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 8, 2008 |
| Grant date | Feb 21, 2012 |
| Priority date | — |
| Expiry date | Dec 22, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/20098
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A shifter incorporates a shape memory alloy wire (SMA actuator) to control movement of a blocker to selectively prevent moving a shift lever (or pawl) out of its park position until predetermined vehicle conditions are met. A mechanical fuse (i.e., flexible overload spring) prevents damage to the SMA actuator where the shift lever (or pawl) can be frictionally stopped from movement despite the contraction of the SMA actuator. The control circuit for the SMA actuator includes a photo-electric switch for stopping electrical power to the SMA actuator when the shift lever is moved from its park position, and the shift lever includes structure for mechanically continuing to hold the switch open while out of park. Further, the control circuit is operably connected to an ignition key retaining mechanism so that the ignition key cannot be removed when the lever is not in its park position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.