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Braun David L C O Minnesota Mi: Unidirectional fluid valve.. Minnesota Mining & Mfg, September 28, 1988: EP0284353-A2 (10 worldwide citation)

The exhalation valve (14) of a respiratory face mask (10), while taking up only a small area, can afford extraordinarily low pressure drop for easy breathing if constructed with a valve seat (16) having a seal edge (18) that defines an orifice (21) and also forms a parabola in the plane bisecting th ...


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Braun David L C O Minnesota Mi, Melvin Donald L C O Minnesota: Respiratory mask having a rigid or semi-rigid, insert-molded filtration element and method of making.. Minnesota Mining & Mfg, March 29, 1989: EP0309277-A2 (8 worldwide citation)

A filtering device is made by inserting into an injection mold a porous, rigid or semi-rigid filtration element that has inflow and outflow faces separated by a peripheral surface and then injecting resin into the flow channel of the mold at a pressure and temperature such that the resin does not si ...


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Braun David L C O Minnesota Mi, Rekow Peter O C O Minnesota Mi: Respirators incorporating bonded adsorbant structures.. Minnesota Mining & Mfg, April 15, 1987: EP0218348-A1 (8 worldwide citation)

Shaped porous filtering structures of substantially uniform thickness and density particularly suited for filtration of gases and vapors comprising spaced adsorbent granules unified into a solid, self-sustaining, unitary, impact-resistant body by adherent binder particles, respirators incorporating ...


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Braun David L C O Minnesota Mi: Elastic strap fastener assembly.. Minnesota Mining & Mfg, April 24, 1991: EP0423977-A1 (1 worldwide citation)

A respirator harnes of polymeric components (10,41,42) and elastic straps (12,43) is made in a 2-part injection mold in a single step. The elastic straps (12,43) are secured to each polymeric component (10,41,42) by a cage that is integral with the polymeric component (10,41,42), and the cage has at ...