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Pneumatic cushion and seal

  • US 4,971,051 A
  • Filed: 03/02/1989
  • Issued: 11/20/1990
  • Est. Priority Date: 07/13/1987
  • Status: Expired due to Term
First Claim
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1. A breathing apparatus comprising:

  • a face mask having a perimeter for fitting against the face of a user, said face mask having a breathing air inlet for flow of air into the mask and an air outlet for flow of air out of the mask;

    an elongate flexible pneumatic cushion seal formed around the perimeter of the mask for flexibly engaging the face of a user and forming a seal to prevent flow of air between the perimeter of the mask and face of the user;

    means for mechanically securing the face mask on a user with the pneumatic cushion seal held against the face of the user to form said seal;

    an air passageway coupled to the pneumatic cushion seal;

    inflatable, expandable and contractible balloon chamber means coupled to said air passageway and in open communication through the air passageway to the elongate pneumatic cushion seal, said balloon chamber means being inflatable to an initial starting volume to provide a desired pressure, said air passageway permitting passage of air back and forth between the pneumatic cushion seal and the expandable and contractible balloon chamber means substantially at said pressure;

    said balloon chamber means being expandable from said initial starting volume to an expanded volume greater than the starting volume when receiving air from the flexible pneumatic cushion seal, and being contractible when air flows therefrom into the flexible pneumatic cushion seal;

    whereby the pneumatic cushion seal can be maintained against the face of a user and follow the changing face contours during user movement by passage of air between the pneumatic cushion seal and expandable and contractible balloon chamber means substantially at the desired pressure thereby changing the volume of air in the pneumatic cushion seal in response to user movement.

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