Product and method for detecting a low level of liquid in a liquid reservoir
US5178091A · kind A · utility
Inventors
Key dates
| Filing date | Sep 28, 1990 |
| Grant date | Jan 12, 1993 |
| Priority date | — |
| Expiry date | Sep 28, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B5/40
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention relates to a novel means for detecting a low level of liquid in a reservoir. One application for the invention is to provide a way to indicate when the level of windshield washer fluid for a vehicle is at a low level. According to one of its broad aspects, the windshield washer fluid noticeable changes color on the windshield, when it is running low in the reservoir; for example, changing from very light blue to an intense red. There are known electrical and mechanical means for indicating the level of a fluid in a reservoir. However, these indicators of fluid level rely on special equipment such as floats and electrical contacts. An advantage of the present invention, is that it can be used with existing windshield washer reservoirs without the need for additional equipment and/or gauges in the interior of the vehicle. According to one aspect of this invention, the windshield washer reservoir contains a first liquid which usually would be ordinary windshield washer fluid, normally of a light blue or light green color and normally comprising a mixture of water, methyl alcohol and a dye. Added to this first liquid in the reservoir is a second liquid having a specific …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.