Fuel dispenser shutoff switch
US5613535A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 5, 1995 |
| Grant date | Mar 25, 1997 |
| Priority date | — |
| Expiry date | Jun 5, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB67D7/48
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A fuel dispensing unit shutoff switch is provided, the switch comprising: a fuel supply nozzle, having a fuel supply outlet, capable of being inserted into a fuel tank inlet conduit of a vehicle; a plurality of vacuum conduits, each vacuum conduit providing communication between a volume in the vicinity of the fuel supply nozzle outlet, and sources of essentially equal negative pressures; a differential pressure sensor having a plurality of inputs with each input being a point along a different vacuum conduit, and an output signal that is activated when the pressures of the vacuum conduits at the differential pressure sensor inputs differ by more than a threshold amount of differential pressures; and a means effective to stop fuel flow when the output signal is activated. The sources of equal negative pressures are preferably one or more venturies in the fuel supply nozzle, and the threshold amount of differential pressure is preferably between about 0.1 and about 3 inches water of differential pressure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.