US996135A - Safety breathing-armor. - Google Patents

Safety breathing-armor. Download PDF

Info

Publication number
US996135A
US996135A US55801010A US1910558010A US996135A US 996135 A US996135 A US 996135A US 55801010 A US55801010 A US 55801010A US 1910558010 A US1910558010 A US 1910558010A US 996135 A US996135 A US 996135A
Authority
US
United States
Prior art keywords
reservoir
armor
nipple
wearer
check valve
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US55801010A
Inventor
George Poe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
HARRIET L OSTRANDER
WILLARD C BOHLKEN
R F MCLAUGHLIN
WILLIAM H VENABLE
Original Assignee
HARRIET L OSTRANDER
R F MCLAUGHLIN
WILLARD C BOHLKEN
WILLIAM H VENABLE
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by HARRIET L OSTRANDER, R F MCLAUGHLIN, WILLARD C BOHLKEN, WILLIAM H VENABLE filed Critical HARRIET L OSTRANDER
Priority to US55801010A priority Critical patent/US996135A/en
Application granted granted Critical
Publication of US996135A publication Critical patent/US996135A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17CVESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C1/00Pressure vessels, e.g. gas cylinder, gas tank, replaceable cartridge
    • F17C1/16Pressure vessels, e.g. gas cylinder, gas tank, replaceable cartridge constructed of plastics materials
    • AHUMAN NECESSITIES
    • A62LIFE-SAVING; FIRE-FIGHTING
    • A62BDEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
    • A62B7/00Respiratory apparatus
    • A62B7/02Respiratory apparatus with compressed oxygen or air

Definitions

  • This invention relates to improvements in respirators such as are applied to a person before entering a room filled with smoke, or a place in which noxious gases are present.
  • One object of the invention is the pro vision of a respirator, including a sleeveless body garment containing a reservoir, and a face mask connected with the reservoir so that the person to whom the deviceis applied may draw the contents of the reservoir through the connection between the latter and the face mask;
  • Another object is the pI'OVlSlOIl of a respirator, including a body garment having suitable pockets for the reception of a gencrating apparatus and also an absorber, communication being established between the generator and reservoir, and "also between the absorber and reservoir, a further connection being established between the face mask and absorber, thus permitting the exhaled gas to pass into the absorber, whence it is freed of carbon-dioxid and watery vapors before returning to the reservoir.
  • the present invention consists in certain novel details of construction, and arrangement of and minor details of the device may be made,
  • Figure l is a front view of a person equipped with my device
  • FIG. 2 is a back view of a person equipped with my improved device, showing the' outline of the reservoir and the connections between the latter and the head mask, generators and absorber;
  • Fig. 3 is a vertical sectional view of the head mask, also showing a portion of the conveying tube and by-pass;
  • Fig. t is a front elevation of the body garment in open position;
  • Fig. 5 is a vertical section taken on the line 5-5 of Fig. 4:.
  • the device forming the subject matter of the present invention is shown 'to include a body garment in the form of an ordinary vest.
  • the front panels of the vest are designated-by the numerals 5 and 6 and are connected together by what will subsequently be termed a reservoir.
  • the reservoir is preferably formed of rubber, and, as shown in Fig. 5, a single piece of rubber is doubled upon itself at its medial portion to provide sides 7 and 8, the ends and sides of which are suitably secured together, as shown at 9, to provide air tight joints.
  • the reservoir thus formed will correspond in area to the usual back panel of a vest, it being understood that suitable arm holes, such as shown at 10, will be provided to permit the wearer to apply the vest to his body.
  • FIG. 1 and 4 it will be seen that the panels 5 and 6 are provided with pockets 11 and 12, and arranged in these pockets are generators 13 and 14: for supplying the reservoir with oxygen and nitrogen gases.
  • a Y coupling is designated by the numeral 15 and tubular connections 16 and 17 have their opposite ends connected with the generators 13 and 14 and with tho diverging limbs of the coupling; connection between the shank of the coupling and reservoir being established by means of a flexible tube 18, which passes over one side of the wearer and is tapped into the reservoir, as shown at 19, in Fig. 5.
  • the face mask is shown to include in its construction a semi-ellipsoidal body, designated by the numeral 20, this body 20 being of a sufiicient size to house the nose and mouth of the wearer.
  • the base of the body 20 is provided with a peripheral flange 21, and positioned on the upper portion of the body is a plate 22.
  • the plate 22 is designed. to extend transverse the lower portion of the forehead of the wearer and is provided, adjacentto its opposite ends, with openings surrounded by flanges 23 and in which are secured lenses 24.
  • a pneumatic cushion is designated by the numeral 25 and is positioned on the inner surface of the flange 21, the said cushion being substantially elliptical in contour and having an extension 26 arranged on the inner surface of the plate 22.
  • the cushion 25 and extensio 26 are provided with headed flaps or fladges 27, which bear on the outer surface of the flange 21 and plate 22 to prevent displacement of the cushion.
  • a head strap in designated by the numeral 28 and has its opposite terminals fixedly secured to opposite points on the body 20, said strap being preferably and serving to secure the mask on the face of the wearer.
  • a tubular extension 29 said tubular extension surrounding a central opening in the body 20, and threaded into the inner end of said extension is a mouth-piece 30, extending well beyond the cushion 25 so that when the mask is posi- Y tioned on the face of the operator, the mouth-piece 30 may readily be received in the mouth of the operator.
  • Threaded into the outer end of the section 29 is a. nipple '31, the inner end portion of the nipple 31 being counter-bored, as at 32, to provide a valve seat, in which is arranged a spherical check valve 33.
  • the check valve 33 being of greater diameter than the bore of the nipple will of course be prevented against outward movement in the nipple, and inward displacement is prevented by means of a bar 34, extending transverse the counter-bore 32.
  • Connection between the nipple 31 and the reservoir established by means of a convcyingtube 35, the opposite ends of which are connected to the outer end portion of the nipple and the upper end portion of the reservoir, as shown at 36.
  • the section 29 is provided at a point between the nipple 3i and the mouthpiece 30 with a radially disposed nipple 37.
  • the outer end portion of the nipple 37 is provided with a counter-bore 38 to provide a valve seat, in which is positioned a spherical check valve 39. Upward and outward movement of the check valve by means of a cross bar 40.
  • a receptacle 42 which contains a quantity of caustic potash.
  • the receptacle 42 is of elastic webbing 39 is prevented provided on its upper end with a pair of spaced nipples which receive one end of a by-pass 43, the opposite end of which is received by the nipple 37 and also one end of a tubular return pipe 44, the opposite end of which is tapped into the upper end portion of the reservoir, as shown at ,45.
  • Fig. 3 it will be seen that the check valves 33 and 39 open alternately, so that when the operator draws through the mouth-piece 30, such action will unseat the check valve 39, thus permitting the mixed gases to pass from the, reservoir through the tube 35 and into the mouth of the wearer.
  • the wearer exhales through his mouth, however, such exhalation will close the check valve and lift the check valye 39, thus permitting the exhaled gases to pass through the by-pass 40 and into the absorber 42, the caustic potash in the latter absorbing the water vapor an carbon-dioxid from v fore the latter passflthrough the 44 and back into the reservoir.
  • the supply of reservoir may be used riod, thus permitting the wearer to remaln a long time in a room or other place filled with noxious gases.
  • the wearer does not desire to permit the exhaled gases to pass" into the absorber, and prefers to exhale through his nose, the exhaled gases may pass to the body 20 in a manner to be presently described by referring, now, to Fig. 3, 'it will be seen that formed in the body 20 and adjacent to the central portion thereof, is an opening, the outer end of which is'surrounded by a the inner end of the opening is a bushing 47. Secured in the outer end portion of the flange l6 is a ring 48, spaced from the' adjacent end of the bushing 47, and positioned between the ring 48 and adjacent end of the bushing, is a bodily movable check valve 49.
  • the check valve 49 normally bears on the end of the bushing 47, and formed in the flange 46 and at a point between the valve 49 and ring, 48 are radial openings 50.
  • the check valve 49 bears on the bushing 47, it will be below the openings 50, but when raised from the bushing 47, communication between the exterior and the interior of the body will be established. Thus it will be. seen, when the wearer exhales through his nose, that the gases in the body 20 will lift the"valve 49 and escape through the openings 50.
  • the check valve When it is desired to exhale through the mouth and as'before described, the check valve may be return tube Thus it will gas from t the rendered secure against accidental movement by means of a latch 52, one end ofwhich is pivoted in the flange end of which is receivable by a recess forme at an opposite point in the flange, the in the exhaled gases beflange 46 and threaded into into the absorber,
  • a respirator comprising a sleeveless body garment aninflatable reservoir. sewed into the back portion of the garment, a plurality of pockets arranged on the opposite sides of 'thefront portion of the "garment, an absorbent holding receptacle insertible into one of said pockets, oppositely positioned gas-holding receptacles arranged in the remainder' of said pockets, a face mask, gasconducting tubes connecting the face mask with the absorbent-holding receptacle, a

Landscapes

  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Emergency Medicine (AREA)
  • Pulmonology (AREA)
  • General Health & Medical Sciences (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Respiratory Apparatuses And Protective Means (AREA)

Description

G. POE.
SAFETY BREATHING ARMOR.
APPLICATION FILED M11. 27, 1910 v 996,135. Patented June 27,1911.
I '2 BHEETS-SHEET 1.
1 flay/991 06,
G. POE.
SAFETY BEEATHING ABMOR. APPLIQATI OiI Hum APR. 27, 1910.
. 996,135? Patented June 27, 1911.
2 BHEETS-SHEET 2.
gi at atto'imeq SATES GEORGE POE, OF NORFOLK, VIRGINIA, ASSIGNOR OF ONE-SIXTEENTH TO R. F. MGLAUGHLIN, OF NORFOLK, VIRGINIA, ONE-FOURTH T0 HARRIET L. OSTRANDER, OF SOUTH NORFOLK, VIRGINIA, AND ONE-SIXTEENTH TO WILLARD C. BOHLKEN AND ONE-EIGHTH TOWILLIAM H. VENABLE, OF NORFOLK, VIRGINIA.
SAFETY BREATHING-ARMOR.
Specification of Letters Patent.
Patented June 27,1911.
App1ication filed April 27, 1910. Serial No. 558,010.
To all whom it may concern: '7 Be it known that I, Gnoncn For, a cltlzen of the United States, residing at Norfolk, in the county of Norfolk and State of Virginia, have invented new and useful Improvements in Safety Breathing-Armor; of which the following is a specification.
This invention relates to improvements in respirators such as are applied to a person before entering a room filled with smoke, or a place in which noxious gases are present.
One object of the invention is the pro vision of a respirator, including a sleeveless body garment containing a reservoir, anda face mask connected with the reservoir so that the person to whom the deviceis applied may draw the contents of the reservoir through the connection between the latter and the face mask;
Another object is the pI'OVlSlOIl of a respirator, including a body garment having suitable pockets for the reception of a gencrating apparatus and also an absorber, communication being established between the generator and reservoir, and "also between the absorber and reservoir, a further connection being established between the face mask and absorber, thus permitting the exhaled gas to pass into the absorber, whence it is freed of carbon-dioxid and watery vapors before returning to the reservoir.
WVith these and other objects in view, that will more fully hereinafter appear, the present invention consists in certain novel details of construction, and arrangement of and minor details of the device may be made,
without departing from the spirit of the invention, or. sacrificing any of the advantages thereof. I
In the accompanying drawings, forming part of the specification: Figure l. is a front view of a person equipped with my device,
showing the generators, absorber and-face mask, and also the connections between these parts and the reservoir; Fig. 2 is a back view of a person equipped with my improved device, showing the' outline of the reservoir and the connections between the latter and the head mask, generators and absorber; Fig. 3 is a vertical sectional view of the head mask, also showing a portion of the conveying tube and by-pass; Fig. t is a front elevation of the body garment in open position; Fig. 5 is a vertical section taken on the line 5-5 of Fig. 4:.
Similar numerals of reference are employed to designate corresponding parts throughout.
The device forming the subject matter of the present invention is shown 'to include a body garment in the form of an ordinary vest. The front panels of the vest are designated-by the numerals 5 and 6 and are connected together by what will subsequently be termed a reservoir. The reservoir is preferably formed of rubber, and, as shown in Fig. 5, a single piece of rubber is doubled upon itself at its medial portion to provide sides 7 and 8, the ends and sides of which are suitably secured together, as shown at 9, to provide air tight joints. The reservoir thus formed will correspond in area to the usual back panel of a vest, it being understood that suitable arm holes, such as shown at 10, will be provided to permit the wearer to apply the vest to his body. By the provision of the sleeveless grament, it will be evident that the movement of the operators arms will be unhampered.
By reference, now, to Figs. 1 and 4, it will be seen that the panels 5 and 6 are provided with pockets 11 and 12, and arranged in these pockets are generators 13 and 14: for supplying the reservoir with oxygen and nitrogen gases. A Y coupling is designated by the numeral 15 and tubular connections 16 and 17 have their opposite ends connected with the generators 13 and 14 and with tho diverging limbs of the coupling; connection between the shank of the coupling and reservoir being established by means of a flexible tube 18, which passes over one side of the wearer and is tapped into the reservoir, as shown at 19, in Fig. 5.
The face mask is shown to include in its construction a semi-ellipsoidal body, designated by the numeral 20, this body 20 being of a sufiicient size to house the nose and mouth of the wearer. The base of the body 20 is provided with a peripheral flange 21, and positioned on the upper portion of the body is a plate 22. The plate 22 is designed. to extend transverse the lower portion of the forehead of the wearer and is provided, adjacentto its opposite ends, with openings surrounded by flanges 23 and in which are secured lenses 24. p
A pneumatic cushion is designated by the numeral 25 and is positioned on the inner surface of the flange 21, the said cushion being substantially elliptical in contour and having an extension 26 arranged on the inner surface of the plate 22. The cushion 25 and extensio 26 are provided with headed flaps or fladges 27, which bear on the outer surface of the flange 21 and plate 22 to prevent displacement of the cushion. A head strap in designated by the numeral 28 and has its opposite terminals fixedly secured to opposite points on the body 20, said strap being preferably and serving to secure the mask on the face of the wearer.
By reference, now, to Fig. 3, it will be seen that the body 20 is centrally provided,
on its outer face, with a tubular extension 29, said tubular extension surrounding a central opening in the body 20, and threaded into the inner end of said extension is a mouth-piece 30, extending well beyond the cushion 25 so that when the mask is posi- Y tioned on the face of the operator, the mouth-piece 30 may readily be received in the mouth of the operator. Threaded into the outer end of the section 29 is a. nipple '31, the inner end portion of the nipple 31 being counter-bored, as at 32, to provide a valve seat, in which is arranged a spherical check valve 33. The check valve 33 being of greater diameter than the bore of the nipple will of course be prevented against outward movement in the nipple, and inward displacement is prevented by means of a bar 34, extending transverse the counter-bore 32. Connection between the nipple 31 and the reservoir established by means of a convcyingtube 35, the opposite ends of which are connected to the outer end portion of the nipple and the upper end portion of the reservoir, as shown at 36.
By referring, again, to Fig. 3, it will be seen that the section 29 is provided at a point between the nipple 3i and the mouthpiece 30 with a radially disposed nipple 37. The outer end portion of the nipple 37 is provided with a counter-bore 38 to provide a valve seat, in which is positioned a spherical check valve 39. Upward and outward movement of the check valve by means of a cross bar 40.
By reference, now, to Figs. 1 and 4, it will be seen that the panel 6 of the vestis provided at a point above the generator 14, with a pocket 41, and arranged in this pocket is a receptacle 42 which contains a quantity of caustic potash. The receptacle 42 is of elastic webbing 39 is prevented provided on its upper end with a pair of spaced nipples which receive one end of a by-pass 43, the opposite end of which is received by the nipple 37 and also one end of a tubular return pipe 44, the opposite end of which is tapped into the upper end portion of the reservoir, as shown at ,45.
By reference, now, to Fig. 3, it will be seen that the check valves 33 and 39 open alternately, so that when the operator draws through the mouth-piece 30, such action will unseat the check valve 39, thus permitting the mixed gases to pass from the, reservoir through the tube 35 and into the mouth of the wearer. When the wearer exhales through his mouth, however, such exhalation will close the check valve and lift the check valye 39, thus permitting the exhaled gases to pass through the by-pass 40 and into the absorber 42, the caustic potash in the latter absorbing the water vapor an carbon-dioxid from v fore the latter passflthrough the 44 and back into the reservoir. be seen that the supply of reservoir may be used riod, thus permitting the wearer to remaln a long time in a room or other place filled with noxious gases. I
\Vhen the wearer does not desire to permit the exhaled gases to pass" into the absorber, and prefers to exhale through his nose, the exhaled gases may pass to the body 20 in a manner to be presently described by referring, now, to Fig. 3, 'it will be seen that formed in the body 20 and adjacent to the central portion thereof, is an opening, the outer end of which is'surrounded by a the inner end of the opening is a bushing 47. Secured in the outer end portion of the flange l6 is a ring 48, spaced from the' adjacent end of the bushing 47, and positioned between the ring 48 and adjacent end of the bushing, is a bodily movable check valve 49. The check valve 49 normally bears on the end of the bushing 47, and formed in the flange 46 and at a point between the valve 49 and ring, 48 are radial openings 50. When the check valve 49 bears on the bushing 47, it will be below the openings 50, but when raised from the bushing 47, communication between the exterior and the interior of the body will be established. Thus it will be. seen, when the wearer exhales through his nose, that the gases in the body 20 will lift the"valve 49 and escape through the openings 50. When it is desired to exhale through the mouth and as'before described, the check valve may be return tube Thus it will gas from t the rendered secure against accidental movement by means of a latch 52, one end ofwhich is pivoted in the flange end of which is receivable by a recess forme at an opposite point in the flange, the in the exhaled gases beflange 46 and threaded into into the absorber,
for an indefinite pei ai 48, and the opposite termediate portion of the la-tch being provided with a lug 53 which bears on the valve 49 and holds the latter to its seat.
a From the foregoing, it will be seen that'I have provided a device comparatively simranged that the danger of derangement is reduced to a minimum.
-What I claim as'new is:
A respirator comprising a sleeveless body garment aninflatable reservoir. sewed into the back portion of the garment, a plurality of pockets arranged on the opposite sides of 'thefront portion of the "garment, an absorbent holding receptacle insertible into one of said pockets, oppositely positioned gas-holding receptacles arranged in the remainder' of said pockets, a face mask, gasconducting tubes connecting the face mask with the absorbent-holding receptacle, a
second gas-conducting tube connecting the v absorbent-holding receptacle with the reservoir, the third gas-conducting tube having 7 one end communicating with the reservoir and its opposite end provided with a- Y- A, coupling, and branch tubes connecting the gas-holding receptacles with the Y-coupling. In testimony whereof I afl'ix my signature in presence of two Witnesses.
' GEORGE POE. Witnesses:
a W. H. VENABLE, W. C. BOHLKEN.
US55801010A 1910-04-27 1910-04-27 Safety breathing-armor. Expired - Lifetime US996135A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US55801010A US996135A (en) 1910-04-27 1910-04-27 Safety breathing-armor.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US55801010A US996135A (en) 1910-04-27 1910-04-27 Safety breathing-armor.

Publications (1)

Publication Number Publication Date
US996135A true US996135A (en) 1911-06-27

Family

ID=3064467

Family Applications (1)

Application Number Title Priority Date Filing Date
US55801010A Expired - Lifetime US996135A (en) 1910-04-27 1910-04-27 Safety breathing-armor.

Country Status (1)

Country Link
US (1) US996135A (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2539284A (en) * 1945-10-18 1951-01-23 Thomas Wilfred Goggles
US2818858A (en) * 1954-03-12 1958-01-07 Old Dominion Res And Dev Corp Underwater breathing apparatus
US2918676A (en) * 1957-05-07 1959-12-29 Electric Storage Battery Co Detachable paddings for goggles
US3266489A (en) * 1963-05-17 1966-08-16 Vickers Res Ltd Breathing apparatus
US4342725A (en) * 1978-10-19 1982-08-03 Preiser Scientific, Incorporated Oxygen supply apparatus
US4890609A (en) * 1988-06-27 1990-01-02 Wilson Ii Robert H Air-directing apparatus for air mask
US4964405A (en) * 1989-09-01 1990-10-23 E. I. Du Pont De Nemours And Company Emergency respiration apparatus
US5370113A (en) * 1991-03-20 1994-12-06 Racal Panorama Limited Breathing apparatus held in a convertible case and garment assembly
US5676135A (en) * 1996-06-25 1997-10-14 Mcclean; Leon Breath saver
US20070051370A1 (en) * 2005-03-09 2007-03-08 Stephen Baker Protective face mask

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2539284A (en) * 1945-10-18 1951-01-23 Thomas Wilfred Goggles
US2818858A (en) * 1954-03-12 1958-01-07 Old Dominion Res And Dev Corp Underwater breathing apparatus
US2918676A (en) * 1957-05-07 1959-12-29 Electric Storage Battery Co Detachable paddings for goggles
US3266489A (en) * 1963-05-17 1966-08-16 Vickers Res Ltd Breathing apparatus
US4342725A (en) * 1978-10-19 1982-08-03 Preiser Scientific, Incorporated Oxygen supply apparatus
US4890609A (en) * 1988-06-27 1990-01-02 Wilson Ii Robert H Air-directing apparatus for air mask
US4964405A (en) * 1989-09-01 1990-10-23 E. I. Du Pont De Nemours And Company Emergency respiration apparatus
US5370113A (en) * 1991-03-20 1994-12-06 Racal Panorama Limited Breathing apparatus held in a convertible case and garment assembly
US5676135A (en) * 1996-06-25 1997-10-14 Mcclean; Leon Breath saver
US20070051370A1 (en) * 2005-03-09 2007-03-08 Stephen Baker Protective face mask
US7228858B2 (en) 2005-03-09 2007-06-12 Baker Stephen G Protective garment
US20100000541A1 (en) * 2005-03-09 2010-01-07 Baker Stephen G Protective garment

Similar Documents

Publication Publication Date Title
US2383649A (en) Breathing mask for parachute escape devices
US996135A (en) Safety breathing-armor.
US2456130A (en) Breathing apparatus
SE448064B (en) RESPIRATORY PROTECTION Mask WITH INTERNAL HALF MASK
US20210121649A1 (en) Portable rebreathing system with staged addition of oxygen enrichment
US2325049A (en) Breathing apparatus
GB1576630A (en) Head protection respiratory device
US4213453A (en) Breathing device having oxygen donor chemical cartridge
GB768865A (en) Self-contained breathing apparatus
CN111388893B (en) Waist-carrying portable respirator
GB775911A (en) Improvements in breathing apparatus for use in aircraft
CN205626670U (en) Respirator is used in child's anesthesia
GB591531A (en) Improvements in respirator masks, especially oxygen masks for aircrews
US1323217A (en) Ventilating-mask
AU2015201443B2 (en) Mine escape self-rescuer system and method
US1090742A (en) Protective uniform.
US2788001A (en) Breathing apparatus of the rebreather type
US2839054A (en) Rapid decompression relief valve
CN211863606U (en) Respirator with automatic pressure relief function
CN111346310B (en) Pressure-controllable respirator
US865996A (en) Mask.
US2310022A (en) Oxygen delivering apparatus of the demand type
US1185392A (en) Air face-mask.
US1454645A (en) Breathing apparatus
CN111388892B (en) Mining respirator