Patent · US Expired

Back flow prevention device

US5678592A · kind A · utility

18Cited by
22References
28Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 26, 1996
Grant dateOct 21, 1997
Priority date
Expiry dateMar 26, 2016

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T137/9464
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

Disclosed is an improved device (10) for preventing back flow of possibly-contaminated water into a potable water system. The device (10) includes first, second and third nozzles (33, 35, 37) in series flow relationship, and an air gap (49) between the first and second nozzles (33, 35). In the improvement, the air gap (49) is a primary air gap and the device (10) includes a secondary air gap (19) fixed with respect to the second nozzle (35). In a more specific aspect of the new device (10), the second and third nozzles (35, 37) are in a tubular housing (41) and the device (10) includes a containment bowl (21) around the housing (41). The secondary air gap (19) includes an aperture (53) in the housing wall (55) and such aperture (53) opens to the containment bowl (21). Other aspects of the new device (10 involve particular nozzle configurations and relationships and a restrictor (103) inhibiting back flow.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.