초록 ▼

A filter element adapted for attachment to a respirator face piece which includes front and rear walls of filter material, a breather tube, and a porous inner layer which maintains the front and rear walls in a spaced-apart relationship over substantially their entire area and which functions to eve

A filter element adapted for attachment to a respirator face piece which includes front and rear walls of filter material, a breather tube, and a porous inner layer which maintains the front and rear walls in a spaced-apart relationship over substantially their entire area and which functions to evenly distribute air flow across the available filter element surface area.

대표청구항 ▼

A filter element comprising (A) substantially coextensive front and rear walls joined to each other along their peripheral edges and defining an interior space between them; the front and rear walls each comprising at least one layer of a filter material, and the rear wall, including said layer of f

A filter element comprising (A) substantially coextensive front and rear walls joined to each other along their peripheral edges and defining an interior space between them; the front and rear walls each comprising at least one layer of a filter material, and the rear wall, including said layer of filter material, having an opening that provides access to the interior space defined by the front and rear walls, (B) a porous layer contained between the front and rear walls which is substantially coextensive with the walls, which maintains the walls is a spaced-apart relationship over substantially their entire area, and which contributes no more than 50% of the total pressure drop across the filter element, and (C) a breather tube having one end that communicates through said opening with the interior space between the front and rear walls, and adapted at its other end for securing the filter element to a respirator face piece.