Crew oxygen mask with pneumatic comfort adjustment

• US 4,915,106 A
• Filed: 02/26/1988
• Issued: 04/10/1990
• Est. Priority Date: 02/26/1988
• Status: Expired due to Term

• Current Assignee: BE Intellectual Property, Inc. (Rtx Corporation)
• Original Assignee: Puritan Bennett Corp. (Medtronic Plc)
• Inventors: McDonald, Thomas K., Aulgur, Charles C., Kidd, Alan E., DiPasquale, David A.
• Primary Examiner(s): Burr, Edgar S.
• Assistant Examiner(s): Lewis, Aaron J.
• Application Number:
  US07/160,658
• Time in Patent Office: 774 Days
• Field of Search: 128/205.11, 128/207.11, 128/205.24
• US Class Current: 128/207.11
• CPC Class Codes: A62B 18/084 Means for fastening gas-masks to heads or helmets

Abstract

A respirator especially constructed for flight crews has a harness strap which can be inflated to a somewhat rigid, self-sustaining orientation to permit one-handed placement of the respirator over the wearer'"'"'s head. Once the respirator is in place, release of a lever for inflating the strap deflates the latter to an orientation sufficient to cause the resilient strap to tightly press a peripheral seal of the respirator mask against nose and mouth areas of the user'"'"'s face. A comfort adjustment to relieve strap tension permits selective reinflation of the strap to a somewhat smaller value than necessary for initial donning of the harness, and the limited reinflation pressure is sufficient for causing the mask to seal against the face during pressure demand breathing. In instances where pressurized breathing is needed, however, pressure within the strap is automatically released so that the strap presents sufficient bias to hold the mask against the face without oxygen leakage therepast.

Claims

1. Safety apparatus for use in an airplane or the like, comprising:

mask means adapted to be fit against the face of a person and including structure presenting, when so fitted, a chamber adjacent the nose and mouth region of said person for the reception of a breathable gas mixture;

means for delivery of said breathable gas mixture to said chamber, including means operably coupled with said mask means for delivery of pressurized oxygen thereto, and regulator means for mixing atmospheric air with said pressurized oxygen to form the gas mixture;

an extensible, inflatable strap element operably connected with said mask means and extendable from a fully deflated position corresponding to a relatively low pressure therewithin which is substantially ambient pressure to a fully inflated position corresponding to full inflation pressure therewithin, and

inflation control means operatively interconnecting said oxygen delivery means and said strap element, comprising manually controlled structure for selective inflation of the strap element to said full inflation pressure in order to extend the strap element to said fully inflated position to permit fitting thereof over the head of the person, and for deflation of the element to engage the head of the person to hold the mask in said fitted position, said inflation control means further including inflation level-maintaining means for selectively establishing and maintaining the level of inflation of the strap element at an intermediate gas pressure less than said full inflation pressure and greater than said relatively low pressure, said inflation level-maintaining means having structure for maintaining said intermediate gas pressure within said strap element without manual manipulation of said inflation control means.

2. Apparatus as set forth in claim 1, said inflation level-maintaining means including structure for maintaining the level of inflation of the strap element at any one of a number of intermediate gas pressures less than said full inflation pressure and greater than said relatively low pressure.

3. Apparatus as set forth in claim 1, including aneroid means operatively coupled with said inflation control means for fully deflating said strap element in the event of depressurization of the atmosphere adjacent said mask.

4. Apparatus as set forth in claim 1, said inflation level-maintaining means and said inflation control means including structure for initial deflation of said element to said fully deflated position thereof, and for selective reinflation of the element to said intermediate gas pressure.

5. Apparatus as set forth in claim 4, said reinflation structure comprising a shiftable valve assembly, and spring means releasably contacting a portion of said valve assembly.

6. Apparatus as set forth in claim 1, said mask means including separate structure for covering only the nose and mouth region of the person.

7. Safety apparatus for use in an airplane or the like, comprising:

mask means adapted to be fit against the face of a person and including structure presenting, when so fitted, a chamber adjacent the nose and mouth region of said person for reception of a breathable gas mixture;

means for delivery of said breathable gas mixture to said chamber, including means operably coupled with said mask means for delivery of pressurized oxygen thereto, and regulator means for mixing atmospheric air with said pressurized oxygen to form the gas mixture;

an extensible, inflatable strap element operably connected with said mask means and extendable from a fully deflated position corresponding to a relatively low pressure therewithin which is substantially ambient pressure to a fully inflated position corresponding to full inflation pressure therewithin; and

inflation control means operatively interconnecting said oxygen delivery means and said strap element, comprising manually controlled structure for selective inflation of the strap element to said full inflation pressure in order to extend the strap element to said fully inflated position to permit fitting thereof over the head of the person, and for establishing an intermediate gas pressure less than said full inflation pressure and greater than said relatively low pressure in said strap element after the element is fitted over the head of the person,

said inflation control means further including fine adjustment structure for selective fine adjustment of the pressure within the strap element after said intermediate gas pressure is established and over a pressure adjustment range substantially less than the pressure difference between said full inflation pressure and said relatively low pressure.

8. Safety apparatus as set forth in claim 7, said fine adjustment structure including override means for preventing elevation of pressure within said strap element above a predetermined maximum pressure during use of the fine adjustment structure.

9. Safety apparatus as set forth in claim 7, said fine adjustment structure including means for raising the pressure within said strap element after said intermediate gas pressure is established.