Respiratory protective device

• US 3,923,053 A
• Filed: 07/29/1974
• Issued: 12/02/1975
• Est. Priority Date: 07/29/1974
• Status: Expired due to Term

• Current Assignee: David Guild Jansson
• Original Assignee: David Guild Jansson
• Inventors: Jansson, David Guild
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Recla, Henry J.
• Application Number:
  US05/492,740
• Time in Patent Office: 491 Days
• Field of Search: 128/142,142.2,142.3,145.5,145.6,145.7,145.8,188,202,203
• US Class Current: 128/205.12
• CPC Class Codes: A62B 7/00 Respiratory apparatus for medical purposes A61M16/00
• CPC Class Codes: A62B 7/10 with filter elements

Abstract

A respiratory protective device is disclosed. The device is of a type which may be used in a noxious environment, such as a firefighting environment. The invention is characterized by a vented chamber of substantially fixed volume, two compliant breathing bags in the chamber, each having a filled volume in the chamber substantially equal to the chamber volume, a valving system to effect alternate normally prolonged use of the breathing bags, a source of oxygen-rich gas, and a scrubber to remove carbon dioxide from the gas. A unique scrubber apparatus is incorporated in preferred embodiments.

Claims

1. A respirator comprising:

a source of oxygen-rich gas;

a chamber having a substantially fixed volume, said chamber being vented;

first and second compliant breathing bags within said chamber, each of said bags having a filled volume within said chamber substantially equal to the volume of the chamber;

means to alternately activate one of said bags for breathing;

means to open said source to fill said activated bag with a quantity of said gas; and

means to vent the other bag as said activated bag is filled, said other bag being contracted by expansion of said activated bag during filling.

2. The respirator of claim 1 further having a breathing conduit loop, said means to activate connecting said activated bag into said loop, said loop including a scrubber to remove carbon dioxide from exhaled gas.

3. The respirator of claim 2 wherein said scrubber comprises separate upstream and downstream chemical scrubber materials within said loop, said upstream scrubber material being an efficient desiccant having a low heat of desiccation and said downstream scrubber material being a molecular sieve which is adsorbent of carbon dioxide and having a low heat of adsorption, whereby scrubbed gas is not substantially heated.

4. The respirator of claim 1 wherein said quantity of said gas from said source filled into said activated bag is less than said filled volume.

5. The respirator of claim 2 wherein said quantity of said gas from said source filled into said activated bag is less than said filled volume.

6. The respirator of claim 1 wherein said means to activate includes means to determine when the concentration of oxygen is at a lowest tolerable level.

7. The respirator of claim 2 wherein said means to activate includes means to determine when the concentration of oxygen is at a lowest tolerable level.

8. In breathing apparatus of the type having a supply source of breathable gas and breathing bag means replenished by said source, the improvement comprising:

a chamber having a substantially fixed volume, said chamber being vented;

first and second alternately active compliant breathing bags within said chamber, each of said bags having a filled volume of sufficient extent within said chamber such that the filling of one bag causes physical interaction thereof with the other bag whereby said other bag is at least partially deflated;

means to alternately activate one of said bags for breathing, the other of said bags to be inactive until thereafter activated; and

means to determine when to switch bags.

9. The improvement of claim 8 wherein said supply source comprises a source of oxygen-rich gas.

10. The improvement of claim 9 further including means to open said source to fill said activated bag with a quantity of said gas, said quantity being less than said filled volume.

11. The improvement of claim 9 further having a breathing conduit loop, said first and second breathing bags being alternately connected into said loop, said loop including a scrubber to remove carbon dioxide from exhaled gas.

12. The improvement of claim 11 wherein said scrubber comprises separate upstream and downstream chemical scrubber materials within said loop, said upstream scrubber material being an efficient desiccant having a low heat of desiccation and said downstream scrubber material being a molecular sieve which is adsorbent of carbon dioxide and having a low heat of adsorption, whereby scrubbed gas is not substantially heated.

13. The improvement of claim 12 further including means to open said source to fill said activated bag with a quantity of said gas, said quantity being less than said filled volume.