TUBE WITH PROTRUSIONS FOR INFLATABLE HARNESS OF BREATHING MASK

1 . An elastic tubular device for inflatable harness of breathing mask, the elastic tubular device comprises a tube and a sheath surrounding the tube, the tube is gas impermeable, supple and has an inner surface and an outer surface, wherein the inner surface of the tube includes a plurality of protrusions.

2 . The elastic tubular device according to claim 1 wherein the protrusions comprise ribs extending along the tube.

3 . The elastic tubular device according to claim 2 having a first end and a second end, and each rib extends continuously between the first end and the second end.

4 . The elastic tubular device according to claim 2 including between 6 and 12 ribs.

5 . The elastic tubular device according to claim 2 wherein in cross section the ribs are evenly distributed.

6 . The elastic tubular device according to claim 1 wherein the protrusions have a tip having an angle ranging between 60 degrees and 120 degrees.

7 . The elastic tubular device according to claim 1 wherein the protrusions extend from a base end to a tip end and the protrusions have a width evenly decreasing from the base end to the tip end.

8 . The elastic tubular device according to claim 1 wherein the tube has a base portion having a smooth inner surface and the protrusions protrude from the inner surface of the base portion.

9 . The elastic tubular device according to claim 8 wherein the protrusions are integral with the base portion.

10 . The elastic tubular device according to claim 1 wherein the protrusions protrude between 0.2 millimeter and 1 millimeter.

11 . The elastic tubular device according to claim 1 wherein the tube is in silicon material.

12 . (canceled)

13 . The elastic tubular device according to claim 1 wherein the sheath is made of a woven cloth of flame resistant meta-aramid yarns.

14 . A breathing mask for aircraft comprising an inflatable harness comprising elastic tubular devices according to claim 1 .