07197774 is referenced by 15 patents and cites 41 patents.

A supplied air helmet 10 comprises a visor 14 and a face seal 12 that is secured to the visor. The face seal 12 includes a sealing member 18 and a frame member 16. The sealing member 18 extends radially inward from the frame member 16 and has first and second regions of permeability 20 and 22. The second region 22 has greater permeability than the first region 20. The use of a face seal 12 that has differentiated permeability allows for a controlled flow of air through the interior of the supplied air helmet 10.

Title
Supplied air helmet having face seal with differentiated permeability
Application Number
10/987512
Publication Number
7197774 (B2)
Application Date
November 12, 2004
Publication Date
April 3, 2007
Inventor
Derek S Baker
Lake Elmo
MN, US
Peter N Yates
Lancaster
GB
Richard D Williams
Lancaster
GB
Peter D Lee
Cleveland
GB
Desmond T Curran
Durham
GB
Agent
Karl G Hanson
Assignee
3M Innovative Properties Company
MN, US
IPC
A62B 18/08
A61F 9/02
View Original Source