US 12,233,292 B2
Anti-fog respirator
John M. Facer, Langley Park (GB); Audra A. Wilson, Gateshead (GB); and Christopher P. Henderson, High Shincliffe (GB)
Assigned to 3M Innovative Properties Company, St. Paul, MN (US)
Filed by 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
Filed on Jul. 21, 2023, as Appl. No. 18/356,443.
Application 18/356,443 is a continuation of application No. 17/356,008, filed on Jun. 23, 2021, granted, now 11,904,191.
Application 17/356,008 is a continuation of application No. 15/682,781, filed on Aug. 22, 2017, granted, now 11,135,460, issued on Oct. 5, 2021.
Application 15/682,781 is a continuation of application No. 11/743,716, filed on May 3, 2007, granted, now 9,770,611, issued on Sep. 26, 2017.
Prior Publication US 2023/0356011 A1, Nov. 9, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. A62B 23/02 (2006.01); A41D 13/11 (2006.01); A62B 18/02 (2006.01)
CPC A62B 23/025 (2013.01) [A41D 13/11 (2013.01); A62B 18/025 (2013.01); A41D 13/1115 (2013.01); A41D 13/1161 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A respirator comprising:
a mask body, wherein the mask body comprises:
a plurality of layers joined together at a perimeter of the mask body, wherein the plurality of layers comprises a cover web and a filtration layer;
a sinus region; and
a primary filtering region;
wherein at least a portion of the sinus region comprises an alteration to its intrinsic structure to significantly increase the pressure drop across the sinus region, wherein the increase in pressure drop is achieved by the alteration of the intrinsic structure of the sinus region, and wherein the alteration of the intrinsic structure does not occur substantially outside the sinus region.