US 6,283,120 B1 · Variable volume ratio compound counterlung

Abstract

A variable volume ratio compound counterlung is disclosed for use with a semi-closed circuit breathing apparatus. The compound counterlung generally comprises a flexible bag member disposed within an outer counterlung member. The flexible bag member and the outer counterlung member are in communication with an exhaled gas area of a breathing loop. The flexible bag member having first and second ends which are attached to said outer counterlung. A pair of depth sensors operatively associated with the flexible bag member are provided to vary the volume of said flexible bag member with changes in depth. The flexible bag member is driven by the outer counterlung to discharge gas stored within the flexible bag member depending on the diver's respiratory minute volume. The collapsing of said outer counterlung member also returns gas stored within the outer counterlung back into the breathing loop. The volumetric capacity of the inner counterlung is controlled by one or more ambient pressure sensing devices with an outer bellows-type counterlung that drives the inner counterlung's contents overboard with each breathing cycle. The invention provides semi-closed cycle passive gas addition for recirculating diver breathing systems that is keyed to both respiratory minute volume and depth by making each discharge mass constant relative to the volumetric relationship of the inner and outer counterlungs at the surface, thus making the system far more gas efficient than previous designs.

Claims20

Dependent claims

A variable volume ratio compound counterlung for use with a semi-closed circuit breathing apparatus, said breathing apparatus including a breathing loop to allow a majority of exhaled gas to travel therethrough and be cleansed of carbon dioxide and ultimately inhaled by a diver utilizing the breathing apparatus, said compound counterlung comprising:

a flexible bag member for communication with an exhaled gas area of the breathing loop;
an outer counterlung member for communication with an exhaled gas area of the breathing loop, said flexible bag member disposed within said outer counterlung member;
means for varying the volume of said flexible bag member with changes in depth;
and
means for discharging gas stored within said flexible bag member depending on the diver's respiratory minute volume;
wherein said flexible bag member is driven by said outer counterlung member to discharge gas stored within said flexible bag member;
wherein collapsing of said outer counterlung member also returns gas stored within said outer counterlung member back into the breathing loop;
wherein the relationship between said outer counterlung member, said flexible bag member, said means for varying and said means for discharging provides for semi-closed cycle passive gas addition that is keyed to both respiratory minute volume and depth by making each discharge mass constant relative to an volumetric relationship of said flexible bag member and said outer counterlung member at surface.

5 more elements

a flexible bag member for communication with an exhaled gas area of the breathing loop;
an outer counterlung member for communication with an exhaled gas area of the breathing loop, said flexible bag member disposed within said outer counterlung member;
means for varying the volume of said flexible bag member with changes in depth;
and
means for discharging gas stored within said flexible bag member depending on the diver's respiratory minute volume;
wherein said means for varying are a pair of depth sensors which act as pressure differential control mechanism to change the volumetric relationship between said flexible bag member and said outer counterlung member;
wherein each of said pair of depth sensors comprising:
a housing member;
a control bellow member having a first end and a second end and disposed within said housing member, said bellow member attached at the first end to said housing member;
a control rod having a first end and a second end, the first end of said control rod disposed within said housing member and attached the second end of said bellow member;
a control arm having a first end and a second end, the first end of said control arm attached to the second end of said control rod, the second end of said control arm attached to said flexible bag member.

8 more elements

a flexible bag member for communication with an exhaled gas area of the breathing loop;
an outer counterlung member for communication with an exhaled gas area of the breathing loop, said flexible bag member disposed within said outer counterlung member, said flexible bag member having first and second ends which are attached to said outer counterlung;
and
a pair of depth sensors operatively associated with said flexible bag member to vary the volume of said flexible bag member with changes in depth;
wherein said flexible bag member is driven by said outer counterlung to discharge gas stored within said flexible bag member depending on the diver's respiratory minute volume;
wherein collapsing of said outer counterlung member also returns gas stored within said outer counterlung back into the breathing loop.

3 more elements

Dependencies are inferred from the claim text.

Variable volume ratio compound counterlung

Life of this patent

Variable volume ratio compound counterlung

Life of this patent

Abstract

Claims20