US2088164A - Breathing apparatus - Google Patents

Description

July 27, 1937,.

BREATHINL APPARATUS Filed 001:. 8, 1934 INVENTOR. I WITNESSES BY 4:693"

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41,} ATTORNEYS} .1. B. DYM 2,088,164

UNITED STATES PATENT OFFICE BREATHING APPARATUS Joseph B. Dym, Pittsburgh, Pa., assignor to Mine Safety Appliances Company, Pittsburgh, a corporation of Pennsylvania Application. October 8, 1934,. Serial No. 747,275

5 Claims.

This invention relates to breathing apparatus, more particularly to portable self-contained oxygen breathing, or inhalation, apparatus, such as, for example, the type used by firemen, in mine 5 rescue work, and for similar purposes.-

Apparatus of the type contemplated herein embodies means for recirculating and regenerating air ina closed cycle to maintain it fit for breathing. .Customarlly it includes a regenerator through which respired air is passed for the removal of carbon dioxide, a cooler for reducing the temperature of the respired and regenerated air, means for introducing into the treated air .a certain amount of oxygen to supply that consumed in respiration, and a mouthpiece through which the regenerated air is inhaled and exhaled into and from the associated regenerating apparatus.

The mouthpiece is provided with an outlet connection to the regenerator for removal of exhaled air,-and an inlet connection for introduction of regenerated air freed from carbon dioxide and admixed with supplemental oxygen.

The present invention applies particularly to improvements in the mouth piece and affiliated elements of such apparatus.

As previously constructed, the inhalation and exhalation tubes leading to and from the mouthpiece have been rigidly connected in fixed position to opposite sides of the mouthpiece.

cause of such rigid construction the weight of the tubes has exerted a lever action upon the mouthpiece, causing a relatively severepressure to be applied to the face or chin of the wearer, thus increasing the-normal discomfort attendant upon artificial breathing means.

Suchapparatus, to be efiicient, must include means to avoid mixing of the regenerated air and the respired air.

To this end the mouthpieces are commonly-provided with a pair of flowcontrolling valves.

One' of these valves is in- .tended to open upon inhalation to permit regenerated air to enter the mouthpiece, the other valve, leading to the exhalation tube, being simultaneously. closed bythe negative pressure created not completely satisfactory.

Conmonly these mouthpiece valves have been positioned either horizontally or substantially vertically. In the use of horizontal valves the weight of the valve members must be ome in the act of breathing, and while the added breathing resistance is small, it may increase the normal breathing effort sufliciently to decrease the efliciency of the wearer, particularly when the apparatus is worn over long periods of time or during periods ofsevere exertion. The vertical type valve does not close by gravity, and it has been found that if the user breathes lightly the valves may not be wholly closed, which may be danger ous. The disadvantages of incomplete valve closure are known to those familiar with the art.

On the-other hand, if the user of such a mouthpiece breathes heavily enough to insure positive closing of the valves, the mouthpiece becomes subject to the disadvantages of those embodying horizontal valvesdue to the added resistance to breathing.

It is among the objects of this invention to provide an improved mouthpiece which avoids the strain heretofore caused by the inhalation and exhalation tubes, provides positive action inhalation. and exhalation valves which require a minimum of breathing efiort and are positively closed irrespective of the breathing force applied to them. l I A further object isto provide an improved nose clip for use with breathing apparatus mouthpieces, which is adjustable to the needs of the wearer.

The invention may be described in connection with the accompanying drawing in which Fig. 1 represents a front view, partly in section, of .the preferred embodiment; and Fig. 2 a front view of the preferred embodiment of the nose clip.

In accordance with the invention the inhalation and exhalation tubes are rotatably connected to the inhalation and exhalation openin'gs, respectively, of the mouthpiece, whereby when the mouthpiece is in use the tubes may be individually rotated upon, or relative to, the mouthpiece to adjust their angle to relieve strain j and thus to afford the most comfortable position 'for the wearer.

With reference to the valve construction embodied in the invention, the mouthpiecev is provided with a pair of gravity actuated valves associated one with the inhalation opening, and another with the exhalation opening, these valves being inclined at an angle such that the valves close positively under the action of gravity, but such that in the act of breathing it is unnecessary to overcome the entire weight of the movable valve members. Most suitably the valves are inclined at anangle approximately 45 to the horizontal.

Having reference now to the drawing, Fig. 1 shows a mouth piece of conventional form including a casing member I having at opposed ends an inlet opening 2 and an outlet opening 3. The mouthpiece is divided into three chambers by a pair of inclined diaphragm members 4 and 5 which are perforated to provide flow openings 6 and 1, respectively. On the upper side of the diaphragms are mounted cages 8, for example of the form conventionally used in breathing apparatus mouthpieces, for limiting the upward movement of flap valve members I0 and II.

These diaphragms thus divide the mouthpiece into an inlet chamber .I2, an outlet chamber I3 and an intermediate chamber I4 which is provided with a forwardly projecting mouth tube I5 of a conventional form.

In the act of inhalation the negative pressure I in chamber I4 causes valve I0 to open to permit regenerated air to be drawn into chamber I4 from inhalation tube I6 through. chamber I2. Simultaneously, the negative pressure in the chamber I4 closes valve II, cutting chamber I3 off from chamber I4. When the wearer exhales there is created a positive pressure in chamber I4 which closes valve IO and opens valve I I, thus establishing communication between chambers I3 and I4 to permit the respired air to pass into outlet chamber I3 and thence to the regenerator, not shown, through exhalation tube II.

In accordance with the invention diaphragms 4 and 5 are mounted at an angle such that the valves close positively through the action of gravity, but substantially away from the horizontal so that it is unnecessary in the breathing act to overcome the entire weight of the valves in causing them to open. With such a construction gravity usually will sufiice to completely close the valves, but should they not do so, the acute angle at which they are mounted suffices to causethem to close tightly upon the application of very slight pressure, as in light breathing. In the embodiment shown these diaphragms are mounted at an angle of approximately 45, which has been found to involve a minimum of breathing resistance while aifording maximum safety to the wearer.

An important aspect of the invention resides in the manner of associating the inhalation and exhalation tubes I6 and IT with the inlet and outlet openings 2 and 3, respectively. In accordance with the invention these tubes are rotatably as-- sociated with the corresponding openings in the mouthpiece. In the embodiment shown the inhalation tube I6 and the exhalation tube II are provided integrally with fittings I8, Fig. 1, adapted to snugly but rotatably engage openings 2 and 3, respectively, as shown in the drawing.

Advantageously the ends of the mouthpiece forming openings 2 and 3 are provided with outwardly extending flanges I9 to insure retention of the tubes thereon. This permits the wearer to ad just the angle of each tube relative to the mouthpiece and independently of each other, to relieve the strain heretofore encountered'with mouthpieces having the tubes rigidly connected to them, as will be understood by those familiar with the use of such apparatus. By thus adjusting these elements maximum comfort is afforded in relation ,to the mouthpiece.

An additional advantage is that with this construction it becomes possible to shorten the overall length of the mouthpiece, thus decreasing the weight of the apparatus, which is advantageous, and affording less interference with the field of vision of the wearer.

associated with any suitable form of regenerating apparatus, the construction of which is well known to those skilled in the art and constitutes no part of the present invention.

Fittings I8 may be of such resiliency as thereby and in cooperation with flanges I9 to'insure retention of the tubes on the mouthpiece. Or, for added safety, various additional means known to the art, such as hose clamps, may be used. In the drawing the tubes are shown as being wrapped to the mouthpiece by wires 20 positioned to act just inside flanges III. This causes the tubes to be held securely on the mouthpiece openings while permitting swivelling movement of the fittings on the mouthpiece. Preferably the wires 20 are covered by adhesive tape 20a.

The mouthpiece is shown as provided with straps adapted'to be passed about the head of the wearer for fastening the mouthpiece in position.

Although in the preferred embodiment fittings I8 are integrally formed with tubes I6 and II, it will be understood that this is not essential to the invention, it being possible to connect separately formed fittings to the tubes by means available in the art.

Breathing apparatus of this type may be provided with a nose clip for the purpose of rendering it easier to breathe through the mouth without inhaling or exhaling air through the nose. As previously constructed, such clips have been of substantially constant and unadjustable tension, and for this reason disadvantages have been encountered in the use of such clips. For instance, the tension of a clip may be satisfactory for one person and entirely unsatisfactory for others, either because it is insufficient to completely close the nasal passages, or because it is so severe as to cause substantial discomfort.

A further feature of the invention resides in a nose clip adapted efliciently to prevent respiration through the nose together with maximum comfort to all persons. In this aspect of the invention the nose clip is constructed to permit adjustment of the tension of the nostril-engaging members. The preferred embodiment is shown in Fig. 2. A pair of nostril-engaging members 2 I, of soft rubber, for example, adapted to be applied to opposite sides of the.,nose for applying pressure thereto to close the nasal passages are individually connected as shown, to bowed springs 22. The extended ends of the springs are overlapped for a substantial distance and engaged slidably by a sleeve member 23. Sleeve member 23 thus holds the springs together to maintain members 2I in position and likewise permits the ends of springs 22 to be moved inwardly or outwardly and thereby to adjust the spring tension applied to the'nostrils through members 2|. In this manner the wearer can adjust the tension of the springs ,to suit his nostril.

The nose clip may be attached to the apparatus, to prevent its loss, in any suitable manner, as by attaching it to a strap 24 associated with the head harness shown in Fig. 1.

According to the provisionsof the patent statutes, I have explained the principle and construction of my invention and-have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the ap pended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim: 1. In a breathing apparatus, a mouthpiece provided with inhalation and exhalation openings disposed laterally of the mouthpiece, an inhalation tube, an exhalation tube, and swivel connections between said inhalation tubeand inhalation opening and between said exhalation tube and exhalation opening.

2. In abreathing apparatus, a mouthpiece provided with inhalation and exhalation openings, an inhalation tube rotatably associated with said inhalation opening, an exhalation tube rotatably associated with said exhalation opening, a pair of oppositely acting valves associated one with each of said openings and controlling admission of fluid to and expulsion of fluid from the mouthpiece, and said valves being associated with the mouth-piece at an acute angle to its longitudinal axis and thereby providing positive gravity clowith each of said openings and controlling admission of fluid to and expulsion of fluid from the mouth-piece, and said valves being associated with the mouth-piece at an angle of substantially 45 degrees to its longitudinal axis and thereby providing positive gravity closure and minimized resistance to breathing created by the valves.

4. In a breathing apparatus, a nose clip comprising a pair of opposed nostril-compressing members each having a bowed spring connected at one end thereto, said spring urging said members towards each other, the extended ends of said springs being overlapped, and a sleeve slidably engaging said overlapped spring portions and thereby permitting adjustment of the pressure exerted by saidsprings on the nostrils. through said members.

5. In a breathing apparatus, a mouth-piece provided with laterally positioned, axially aligned inhalation and exhalation openings disposed at opposite ends of the mouth-piece, an inhalation tube, an exhalation tube, and swivel connections between said inhalation tube and inhalation opening and between said exhalation tube and exhalation opening.

JOSEPHB. DYM.

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