Elastic tubular device and inflatable head harness for aircraft breathing mask
Described are elastic tubular devices including an inner tube ( 23 ) made of an elastic and gas impermeable material; and a sheath ( 21 ) surrounding the inner tube and made of a woven cloth of flame resistant meta-aramid yarns, wherein the tubular device has a longitudinal extension of at least approximately 1.4 when inflated by a gas having a pressure of at least approximately 0.5 bar.
1. A breathing mask for aircraft comprising an inflatable harness composed of at least one elastic tubular device, each elastic tubular device comprising:
an inner tube made of an elastic and gas impermeable material; and
a sheath surrounding the inner tube and made of a woven cloth of flame resistant meta-aramid yarns, wherein
the tubular device has a longitudinal extension of at least 1.4 when inflated by a gas having a pressure of 0.5 bar.
2. The breathing mask according to claim 1 , wherein the tubular device has a longitudinal extension of at least 1.5 when inflated by a gas having a pressure of 0.7 bar.
3. The breathing mask according to claim 1 , wherein the inner tube is molded in silicon material.
4. The breathing mask according to claim 1 , wherein said sheath is woven so that its longitudinal stretch ratio is approximately 3.
5. The breathing mask according to claim 1 , wherein said tubular device is connected to a gas source through nozzles, said nozzles comprising a cylindrical cover which gets wider in the direction of the tubular device.
6. The breathing mask according to claim 1 , wherein the inner tube fits completely within the sheath when not inflated.
7. The breathing mask according to claim 1 , wherein the inner tube of said tubular device has at least one end portion fixed inside a cylindrical cover and an extensible portion away from the cylindrical cover, the end portion is thicker than the extensible portion of the inner tube, said end portion of the inner tube having an external surface flush with an external surface of said extensible portion of the inner tube.
8. The breathing mask according to claim 1 , wherein the inner tube of said tubular device has at least one portion fixed inside a cylindrical cover and an extensible portion, at least most of the inner tube which is inside the cylindrical cover has an internal cross section smaller than the internal cross section of said extensible portion of the inner tube.
9. A breathing mask for aircraft comprising an inflatable harness composed of at least one elastic tubular device, each elastic tubular device comprising:
an inner tube made of an elastic and gas impermeable material; and
a sheath surrounding the inner tube and made of a woven cloth of flame resistant meta-aramid yarns, wherein
the tubular device has a longitudinal extension of at least 1.4 when inflated by a gas having a pressure of 0.5 bar, and
the inner tube is molded in silicon material having a hardness of less than 75 shore A, and Young's modulus of less than 200 MPa.
10. The breathing mask according to claim 9 , wherein said silicon has a hardness of less than 35 shore A.
11. The breathing mask according to claim 9 , wherein an internal diameter of the inner tube is at least 17 millimeters.
12. The breathing mask according to claim 9 , wherein the inner tube of said tubular device has at least one end portion fixed inside a cylindrical cover and an extensible portion directly connected to said end portion, the end portion is thicker than the extensible portion of the inner tube, said end portion of the inner tube having an internal cross section smaller than an internal cross section of said extensible portion of the inner tube.
13. The breathing mask according to claim 9 , wherein the inner tube of said tubular device has at least one end portion fixed inside a cylindrical cover and an extensible portion away from the cylindrical cover, the end portion is thicker than the extensible portion of the inner tube, said end portion of the inner tube having an external surface flush with an external surface of said extensible portion of the inner tube.
14. The breathing mask according to claim 9 , wherein said tubular device is connected to a gas source through nozzles, said nozzles comprising a cylindrical cover which gets wider in the direction of the tubular device.
15. A breathing mask for aircraft comprising an inflatable harness composed of at least one elastic tubular device, each elastic tubular device comprising:
an inner tube made of an elastic and gas impermeable material; and
a sheath surrounding the inner tube and made of a woven cloth of flame resistant meta-aramid yarns, wherein
the tubular device has a longitudinal extension of at least 1.4 when inflated by a gas having a pressure of 0.5 bar, and
an internal diameter of the inner tube is at least 17 millimeters.
16. The breathing mask according to claim 15 , wherein the inner tube of said tubular device has at least one end portion fixed inside a cylindrical cover and an extensible portion directly connected to said end portion, the end portion is thicker than the extensible portion of the inner tube, said end portion of the inner tube having an internal cross section smaller than an internal cross section of said the extensible portion of the inner tube.
17. The breathing mask according to claim 15 , wherein ends of the inner tube of said tubular device are fixed inside a cylindrical cover and are thicker than another part of the inner tube, said ends of the inner tube having an external cross section identical to an external cross section of said other part of the inner tube.
18. The breathing mask according to claim 15 , wherein said tubular device is connected to a gas source through nozzles, said nozzles comprising a cylindrical cover which gets wider in the direction of the tubular device.
19. A breathing mask for aircraft comprising an inflatable harness composed of at least one elastic tubular device, each elastic tubular device comprising:
an inner tube made of an elastic and gas impermeable material; and
a sheath surrounding the inner tube and made of a woven cloth of flame resistant meta-aramid yarns, wherein
the tubular device has a longitudinal extension of at least 1.4 when inflated by a gas having a pressure of 0.5 bar, and
the inner tube of said tubular device has at least one end portion fixed inside a cylindrical cover and an extensible portion directly connected to said end portion, the end portion is thicker than the extensible portion of the inner tube, said end portion of the inner tube having an internal cross section smaller than an internal cross section of said extensible portion of the inner tube.
20. The breathing mask according to claim 19 , wherein said tubular device is connected to a gas source through nozzles, said nozzles comprising a cylindrical cover which gets wider in the direction of the tubular device.