Filter respirator for protection against smoke and toxic gases

Claim 1

A respirator for protection against smoke and toxic gases, comprising a respirator body having means to cover the breathing passages of a user, means for attachment of said body to the head of a user, said body defining with the head of a user a breathing cavity, said body being provided with an inlet opening communicating the breathing cavity to a source of smoke and toxic gases, said opening shaped to detachably receive a cylindrical filter vessel, said body also having discharge ports, a discharge valve means attached over said discharge ports so as to open the discharge ports only when the user wearing the respirator exhales, a cylindrical filter vessel, said filter vessel being detachably received in said opening and further comprising an outer end wall with intake holes adjacent said source of gases and an inner end wall with intake ports adjacent said breathing cavity, an intake valve means attached over the intake ports of the inner end wall so as to open said intake ports only when the user wearing the respirator inhales, a noble-metal oxidizing catalyst disposed within said filter vessel adjacent to said inner end wall, an electrostatic smoke-filtering material comprising an unwoven fiberous material which has been subjected to electrostatic charging treatment, and an activated carbon fiber material, said smoke-filtering material and activated carbon fiber material being disposed within said filter vessel upstream from said noble-metal catalyst with respect to the flow of smoke and toxic gases from said intake holes to said intake ports, whereby smoke is prevented from arriving at the noble-metal catalyst.