Diaphragm
AssigneeDraeger Safety UK Limited
InventorPaul Townsend
Life of this patent
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Abstract
A diaphragm for a lung demand valve, including a chemical, biological, radiological and/or nuclear (CBRN) layer which is sufficiently resistant to the permeation of at least some CBRN agents and a resilient layer which is resiliently deformable. The CRBN layer is arranged to restrict the permeation of at least some CBRN agents through the diaphragm, and the resilient layer is arranged to allow the diaphragm to be resiliently deformed.
Claims24
A diaphragm for a lung demand valve, comprising:
- a CBRN layer which is sufficiently resistant to the permeation of at least some CBRN agents;
- and
- a resilient layer which is resiliently deformable;
- wherein the CRBN layer is arranged to restrict the permeation of at least some CBRN agents through the diaphragm, and wherein the resilient layer is arranged to allow the diaphragm to be resiliently deformed,
- wherein the resilient layer is discontinuous, and
- wherein the resilient layer comprises at least one opening.
A method of upgrading a lung demand valve such that it is suitable for use in CBRN environments, comprising removing a conventional diaphragm from a lung demand valve, and subsequently fitting the lung demand valve with a diaphragm comprising:
- a CBRN layer which is sufficiently resistant to the permeation of at least some CBRN agents;
- and
- a resilient layer which is resiliently deformable, discontinuous and comprises at least one opening;
- wherein the CRBN layer is arranged to restrict the permeation of at least some CBRN agents through the diaphragm, and wherein the resilient layer is arranged to allow the diaphragm to be resiliently deformed.
A lung demand valve, comprising:
- a main housing defining an internal chamber;
- a breathing port which is in fluid communication with the internal chamber and through which in use a user inhales;
- a breathable gas inlet which in use is connected to a supply of breathable gas;
- a valve assembly for controlling the supply of breathable gas to the user through the internal chamber and breathing port;
- a diaphragm for controlling the valve assembly and which in use responds to the inhalation and exhalation of the user;
- wherein the diaphragm comprises:
- a laminate structure comprising a continuous CBRN layer which is sufficiently resistant to the permeation of at least some CBRN agents and a discontinuous resilient layer which is resiliently deformable, said discontinuous resilient layer comprising at least one opening;
- wherein the CRBN layer is arranged to restrict the permeation of at least some CBRN agents through the diaphragm, and wherein the resilient layer is arranged to allow the diaphragm to be resiliently deformed.
Dependencies are inferred from the claim text.