US 2008/0257352 A1 · Respirator Exhalation Unit

Abstract

A respirator exhalation unit (10) comprises a negative pressure valve (120) and a selectively actuable positive pressure valve assembly (130). The position of the positive pressure valve assembly (130) is selectively adjustable to convert the exhalation unit (10) for use in multiple operating modes, such as a negative pressure mode, a powered air mode, and a self-contained breathing apparatus mode (SCBA). Additionally, a closed circuit breathing apparatus (CCBA) adapter assembly (200) can be attached to the exhalation unit for conversion to a CCBA operating mode. Further, the negative pressure valve (120) divides the interior of the exhalation unit into two chambers, one of which functions as a dead space that protects the user from exposure to any harmful contaminants at the end of exhalation.

Claims28

Dependent claims

An exhalation unit for a respirator, the exhalation unit comprising:

a body defining a conduit having an inlet and an outlet;
a negative pressure valve within the conduit for preventing air from flowing through the conduit from the inlet to the outlet when an air pressure differential between an upstream side and a downstream side of the negative pressure valve is below a first cracking pressure;
and
a selectively operable positive pressure valve within the conduit for preventing the air from flowing through the conduit from the inlet to the outlet when an air pressure differential between an upstream side and a downstream side of the positive pressure valve below a second cracking pressure;
wherein the second cracking pressure is greater than the first cracking pressure.

2 more elements

Dependencies are inferred from the claim text.

Respirator Exhalation Unit

Life of this patent

Respirator Exhalation Unit

Life of this patent

Abstract

Claims28