Flow switch
US4996396A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 30, 1989 |
| Grant date | Feb 26, 1991 |
| Priority date | — |
| Expiry date | Oct 30, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H35/405
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention contemplates a flow-switch construction of the straight flow-through variety wherein a magnet-bearing piston is displaced in response to a hydraulic-flow condition and in the displacement is caused to operate a magnetic-reed switch. The piston has piloted guidance in a first longitudinal portion of an elongate bore but is characterized by one or more straight channels in its periphery, whereby the piston per se constitutes relatively little restriction to flow; the downstream end of the piston carries a metering disc which substantially resists channel flow as long as the metering disc has predetermined close-clearance relation with the first longitudinal portion of the bore. Immediately downstream from the first longitudinal portion, the bore is substantially enlarged in a second longitudinal portion, whereby upon piston displacement such as to advance the metering disc into the second longitudinal portion, the metering disc is by-passed and unrestricted straight-through flow proceeds to the outlet end of the bore.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.