Composite wall, notably motor vehicle windshield, including an ultrasonic device for detecting the presence of foreign bodies on one of its faces
US5598380A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 1995 |
| Grant date | Jan 28, 1997 |
| Priority date | — |
| Expiry date | Jan 17, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S318/02
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
The composite wall comprises a first sheet and second sheet separated by an intermediate layer as well as an ultrasonic detection device placed on a face of said second sheet and comprising a transducer element able to emit an incidental ultrasonic signal of frequence f, and able to receive an ultrasonic signal reflected on a face of said first sheet. The intermediate layer comprises at least facing the transducer element, an inserted element whose two faces are respectively in close contact with the first and second sheets. Further, the frequence f of the transducer element satisfies the following relationships: EQU f.apprxeq.K.sub.1. V.sub.1 /2e.sub.1 .apprxeq.K.sub.2.V.sub.2 /2e.sub.2 .apprxeq.K.sub.3.V.sub.3 /2e.sub.3 where K.sub.1, K.sub.2 and K.sub.3 are defined integers, e.sub.1, e.sub.2 and e.sub.3 are respectively the thickness of the first sheet, the second sheet and the inserted element, and V.sub.1, V.sub.2 and V.sub.3 are respectively the propagation speeds of an ultrasonic wave in the first sheet, in the second sheet and in the inserted element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.