Safeness indicator for flexible shafts used in automotive steering mechanisms
US4398173A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 8, 1981 |
| Grant date | Aug 9, 1983 |
| Priority date | — |
| Expiry date | Oct 8, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S310/80
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
In a vehicle steering system for automobiles, for example, a steering column is provided with a rotatable flexible shaft at the end thereof for improving the ability of the column to absorb energy in a crash situation. The flexible shaft has at least one strip of a plastic material, preferably polyvinylidene fluoride film made piezoelectric by known methods, secured to an outermost winding of the flexible shaft. Turning the steering wheel will torsionally deflect the flexible shaft which causes the piezoelectric strips to generate millivoltages thereacross. A deteriorating flexible shaft will deflect more under torsional stress than a comparable newer flexible shaft and the piezoelectric strip or strips secured to the deteriorating shaft will consequently produce higher millivoltages. These millivoltages are amplified and fed to indicating means for indicating the degree of safeness of the flexible shaft.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.