Protective breathing apparatus and valve therefor

• US 3,990,439 A
• Filed: 12/05/1974
• Issued: 11/09/1976
• Est. Priority Date: 12/05/1974
• Status: Expired due to Term

• Current Assignee: C & D Acquisition Corporation
• Original Assignee: ESB, Inc. (Caixa de Previdência Dos Funcionários Do Banco Do Brasil)
• Inventors: Klinger, Guy G.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/529,859
• Time in Patent Office: 705 Days
• Field of Search: 128/140 R, 128/141, 128/145.7, 128/146, 128/146.4-146.7, 128/142.4, 251/85, 251/159, 251/172, 251/331, 251/333, 137/525, 137/525.1
• US Class Current: 128/207.12
• CPC Class Codes: A62B 18/10 Valves
• CPC Class Codes: F16K 15/148 the closure elements being fixed in their centre
• CPC Class Codes: Y10T 137/789 Central mount

Abstract

A respirator or gas mask has a check valve having a seat with a raised border. A soft rubber valve is located on the seat and held thereto by a valve retainer. When the valve is not under any pressure, the valve is sealed solely by contact between the rim of the valve and the raised portion of the seat. When back-pressure is placed on the valve, it seats on the entire valve seat area.

Claims

1. A check valve assembly of the sort which is open when exposed to a forward air pressure and is closed when in a static condition and when exposed to a reverse air pressure, for use in a breathing apparatus which comprises:

a. a valve body, the valve body being made of a non-deformable material, the valve body defining a valve seat, the valve seat including a flat ring shaped inner portion having a first outside diameter and a circular concavely shaped outer portion blending into the inner portion, the outer portion having a border, the border having a second diameter greater than the first diameter of the inner portion; and

,

b. a circular elastic valve disc made by cutting it from a flat sheet and having a face and a sharp edge, the diameter of the edge being greater than the first outside diameter of the inner portion of the valve seat and less than the second diameter of the outer portion border, the valve disc being located within the confines of the valve seat, and the axis of the valve disc being on the axis of the valve seat, so than when there is no pressure on the valve disc, the edge of the valve disc engages the concave outer portion of the valve seat in a line contact, with the remainder of the valve disc being free of contact with the flat inner portion of the valve seat, and when the valve disc is exposed to a reverse air pressure, the face of the valve disc engages the entire surface of the flat ring shaped inner portion of the valve seat.

2. A valve assembly for use in breathing apparatus which comprises:

a. a valve body, the valve body being made of a non-deformable material, the valve body defining a valve seat, the valve seat including a flat ring shaped inner portion having a first outside diameter and a circular concavely shaped outer portion blending into the inner portion, the outer portion having a border, the border having a second diameter greater than the first diameter of the inner portion, the valve body further defining a valve support at the center of the valve seat, the surface of the valve support being a continuation of the flat inner portion of the valve seat, an aligning pin located on the axis of the seat and extending above the surface of the valve support, and openings in the inner portion to permit a flow of air therethrough;

b. a circular elastic valve disc made by cutting it from a sheet and having a face and a sharp edge, the diameter of the edge being greater than the first outside diameter of the inner portion of the valve seat and less than the second diameter of the outer portion border, the valve disc defining at its center an opening, the opening being an engaging fit on the aligning pin of the valve body, the valve disc being located within the confines of the valve seat, the axis of the valve disc being on the axis of the valve seat, and the opening in the valve disc being located on the aligning pin;

c. a valve retainer made of a non-deformable material, the retainer having a circular shape and an end, the diameter of the end of the retainer being less than the diameter of the inner portion of the valve seat, an opening defined in the end of the retainer on the axis thereof, the diameter of the opening being sufficient to accept the aligning pin of the seat member; and

,

d. means for positioning the valve retainer in relationship to the valve body such that the axis of the retainer is on the axis of the valve body and when the valve disc is located on the aligning pin of the valve body it is held between the end of the valve retainer and the valve support, the edge of the valve disc is in line contact with the outer portion of the valve seat, the portion of the valve disc held by the end of the valve retainer is in sealing contact with the valve support, and the remaining portions of the valve disc are free of contact with the valve seat.

3. A valve assembly as defined in claim 2 wherein the outer portion of the valve seat has the shape of a portion of a circular toroid and the inner portion of the seat is tangent to the inner portion of the toroidal shaped outer portion of the valve seat.

4. A valve assembly as defined in claim 2 wherein the edge of the valve disc is at right angles to the face of the valve.

5. In a protective breathing device for protecting a wearer from injurious atmospheric environments, the device including a shell portion, a means for sealing the shell portion to the face of the wearer, the shell further defining a plurality of apertures, the improvement which comprises:

a. a valve body, the valve body being made of a non-deformable material, the valve body defining a valve seat, the valve seat including a flat ring shaped inner portion having a first outside diameter and a circular concavely shaped outer portion blending into the inner portion, the outer portion having a border, the border having a second diameter greater than the first diameter of the inner portion, the valve body further defining a valve support at the center of the valve seat, the surface of the valve support being a continuation of the flat inner portion of the valve seat, a aligning pin located on the axis of the seat and extending above the surface of the valve support, and openings in the inner portion to permit a flow of air therethrough;

b. a circular elastic valve disc made by cutting it from a flat sheet and having a face and a sharp edge, the diameter of the edge being greater than the first outside diameter of the inner portion of the valve seat and less than the second diameter of the outer portion border, the valve disc defining at its center an opening, the opening being an engaging fit on the aligning pin of the valve body, the valve disc being located within the confines of the valve seat, the axis of the valve disc being on the axis of the valve seat, and the opening in the valve disc being located on the aligning pin;

c. a valve retainer made of a non-deformable material, the retainer having a circular shape and an end, the diameter of the end of the retainer being less than the diameter of the inner portion of the valve seat, an opening defined in the end of the retainer on the axis thereof, the diameter of the opening being sufficient to accept the aligning pin of the seat member; and

,

d. means for positioning the valve retainer in relationship to the valve body such that the axis of the retainer is on the axis of the valve body and when the valve disc is located on the aligning pin of the valve body it is held between the end of the valve retainer and the valve support, the edge of the valve disc is in line contact with the outer portion of the valve seat, the portion of the valve disc held by the end of the valve retainer is in sealing contact with the valve support and the remaining portions of the valve disc are free of contact with the valve seat.

6. A protective breathing device as defined in claim 5 wherein the protective breathing device is a gas mask.

7. A protective breathing device as defined in claim 5 wherein the protective breathing device is a respirator.