US2747572A - Breathing apparatus - Google Patents

Description

May 29, 1956 E. GAGNAN 2,747,572

BREATHING APPARATUS Filed Sept. 29, 1952 2 Sheets-Sheet 2 Tron/v6) m m NW /i/ R N 9 G FM 5 u u r 1 I I l l I I nm k mm 9w Om/ United States Patent panama APPARATUS Emile Gagnan, Montreal, Quebec, Canada, assignor to La Spirotechnique, Paris, France Application September 253, 1952, Serial No. 312,052

-Claims. (Cl. 128-142) The present invention relates to breathing apparatus in general and more especially respiratory apparatus for deep sea diving in which a breathable gas, compressed under a high pressure inside a cylinder, is expanded to a pressure close to that of the ambient medium before being admitted into the respiratory tracts of the user through a mouth-piece placed at the junction of two distinct channels reserved, one for breathing in, the other one for breathing out.

In most known apparatus of this general type, the mouthpiece is in communication with a pressure regulator placed on the breathing in channel and provided with a deformable wall or diaphragm, the outer face of which is subjected to the pressure of the ambient medium. A valve, coupled with this diaphragm, controls the admission in the chamber of the regulator, of the gas from the cylinder and this valve is closed when the diaphragm is in its equilibrium position, i. e. when the pressure on its two faces are substantially equal. When the user breathes in, the diaphragm is depressed and opens the valve which closes again when the breathing in ceases. Expiration takes place in the ambient medium, through a valve, without going through the expansion chamber of the regulator. Expiration takes place through a diiferent channel from breathing in. Precautions have to be taken to avoid a spontaneous delivery of air in the ambient medium (particularly in water) when the respective positions of the diaphragm and expiration valve give rise to a pressure difference higher than that which operates the regulator. In some apparatus, the remedy consists in bringing back expiration to a point close to the diaphragm, through a special duct. In other apparatus, a loading of the expiration valve allows it to open only above a predetermined pressure difierence. In the first case, the apparatus is bulky and the complication of the return pipe and the mounting arrangement for the expiration valve increase its price. In the second case, the counter-pressure, during expiration, is very important in certain positions and tires the diver.

The invention obviates these drawbacks and has for its main object to provide a breathing apparatus for divers in which the stream of expired gas alone goes through the chamber adjacent the diaphragm, while the stream of breathed in gas goes directly from the gas supply valve to the mouth-piece without going through said chamber.

Another object of the invention is to place the gas supply valve close to the mouth piece while holding it far enough from the diaphragm to obtain, by means of a simple connecting device, reduced, for instance, to a single lever, an important reduction between the displacements of the diaphragm and the corresponding lifts of the valve. There is thus obtained an extremely low breathing in effort, and it is possible to use a diaphragm with a small diameter but preferably large displacements, the sensitivity of which is of the same order as that of the wide diaphragms with small displacements, of previous ap paratus.

Still another object of the invention is to provide an 2,747,572 Patented May 29, 1 956' arrangement in which the expiration valve is provided on the diaphragm itself, the centers of thrust of these two elements being in coincidence, which absolutely eliminates the possibility of the leaks of breathable gas, even with .a regulator operating at a very low depression. Further, this arrangement is extremely favourable forthe diver since the latter is supplied with fresh breathable gas and does not re-inhale any previously expired gas.

The invention has for further objects to provide a breathing apparatus for divers, in which:

The diaphragm is of the bellows type having a flexible skirt bent back on itself and is secured, by one edgeon thecasing of the apparatus and, by the other edge on a movable part carrying the expiration valve;

The casing which contains the diaphragm is extended radially by a rigid tube, the. free end of which is connected with the inlet of breathable gas and contains the gas supply valve, the mouth-piece being mounted directly on said rigid tube, between the flap and casing;

The diaphragm is coupled with the gas supply valve by a lever arranged in the tube of the casing, and the body orbox for the gas supply valve is mounted atthe end of said tube and acts as a connection wtih the inlet duct for breathable gas, and the control lever for said valve is mounted permanently on said body with which it constitutes one assembly which may be inserted into the apparatus or withdrawn therefrom as a whole;

A first stage regulator is provided at the breathable gas cylinder outlet, and acalibrated orifice is interposed ahead of the outlet valve of said regulator to actas a brake on the gas flowing and cause a hindrance to breathing in whenthe pressure inside the cylinder has dropped to predetermined value.

Other objectsrand advantageous features of the invention willbe set forth in the following description of an embodiment of a breathing apparatus according to said invention and shown in the accompanying dr wings.

Figure 1 is a section through the whole apparatus, by a plane containing the axis common to the casing and diaphragm and thetube axis.

Figure 2 is a partial section along line ll-ll of Figure 1.

Figure 3 is an axial section, on a larger scale, of the valve box for the supply of breathable gas.

Figure 4 is an axial section, on a large scale, of, a regulator interposed between the breathable gas cylinder outlet and the gas supply valve box.

The improved breathing apparatus according to the invention can be used at will in a gaseous or liquid medium. To simplify the description, however, it will be assumed, hereinafter, that the breathing apparatus is used placements, consists of a skirt made of a thin, flexible foil, impervious to water and to gases. This skirt, for instance, is, as shown, folded once on itself, and glued or secured otherwise in any suitable manner, in the area close to its inner edge, on the side wall of a rigid, light bell 7, made of a plastic material, for instance, guided by-an axial tube 8 on a pin 9 which may be anchored,

by moulding into the plastic material of the casing. The

outer edge of the diaphragm 6 is held on a seat 10 of the casing by a cover 11, preferably, also, of plastic material. 'The cover is provided with holes 12 whichipro- 'vide a permanent communication with the outside, said' holes being so located that bubbles released in the water I by expiration, do not hinder the vision of the diver.

According to one feature of the invention, the expiration valve is carried or constituted by the diaphragm. In the embodiment considered, the expiration valve consists of a flexible disc 13, of rubber for instance, applied on the outer face of the bottom 7a of the bell 7 which acts as a seat, and it is fixed centrally on said bottom, for instance in a suitable groove provided in an ex-. tension 14- of the rod 8.

The important displacements of the diaphragm 6 which control the lifting of the valve for the delivering of breathable gas, should obviously be considerably reduced. With the arrangement special to the invention, a suitable reduction is obtained easily and simply by means of a single lever. In the embodiment shown, this lever is constituted by a rod 15 cut out from a metal sheet and bent at one end so as to provide a heel 15a having a hole for engaging the rod 16 of the valve between the box 17 thereof and a collar 18 provided on the rod 16.

The other end of the lever 15 is, for instance, in the shape of a fork 19, turned over in a plane perpendicular on the axis'of the bell 7 and engaged in a groove 20 of the tube 8.

Figure 3 shows the position of the heel 15a, when the valve 21 is closed and Figure 1 shows the lever 15 and its heel 15a in the opening position of this valve.

According to an advantageous feature of the invention, the box 17 for the valve 21 constitutes a single unit with the coupling nipple 22 for connection with the flexible hose, not shown, supplying the breathable gas. The valve 21 is guided with its rod 16in a cap 23, screwed at 24 on the box 17 and it is urged towards its seat by a spring 24. The box 17, provided with orifices 25 for the gas outlet engages, by its bearing 17a, the end of the tube 2 and is locked and sealed by its flange 17b by means of a nut 26 screwed on a screw thread 27 of said tube 2. The valve box 17 and lever 15 constitute one unit which may be bodily inserted into or withdrawn from'the apparatus as a whole. This metal unit carryingthe gas inlet pipe advantageously balances the whole of the apparatus.

As usual in apparatus of this general type, the pressure of breathable gas is lowered, at the outlet of the cylinder, to a pressure of a few atmospheres above the ambient water pressure. Figure 4 shows an embodiment of a regulator specially designed to this effect, and remarkable, besides, by its compact construction of very small dimensions and in that it behaves as an air'reserve indicator for Warning the diver that there only remains in the cylinder the amount of air. necessary for instance for efiecting, in normal conditions, the ascent from a predetermined depth.

'The body 28 of this regulator is connected directly to the outlet from the cylinder, by a threaded tail piece 29, the outlet of air or other breathable gas taking place through a duct 30, which extends to a wall 31 on both sides of which are arranged the valve 32 of the regulator and the diaphragm 33 for adjusting the pressure at the outlet from the apparatus.

The diaphragm 33 is held by its outer edge between an annular bearing 34 of the body 28 and a screwed cap 35, the inner cavity of which communicates with the ambient water through holes 36. The diaphragm is perforated centrally for the passage of a rod 37 on the base 38 of which this diaphragm is normally applied by a washer 39 subjected to the thrust of a spring 40 which acts in the same direction as the water pressure on the outer face of the diaphragm.

The valve 32 consists for instance, in a ball carried by a slide block 41 guided in the boring of a part 42 screwed at 43 into the body 28, said part being provided.

of air towards the nipple 44 is ensured, for example by 7 46 interposed between the base 38 and the slide block 41 and guided in'holes 47 which go through the wall 31. A passage 48 is provided in the wall 31 to set up a permanent communication between the two cavities on both sides of this wall. The operation of this regulatoris similar to that of the regulators based on the same principle, the characteristics of the springs 40 and 45 being determined for maintaining, downstream with respect to the valve 32, a given pressure above the pressure of the ambient water which is exerted on the outer face of the diaphragm. It will be noted that the central portion of the diaphragm acts, in cooperation with the washer 39 and the base 38 as a safety valve for discharging the cavity 49 in the ambient water in case of a dangerous overpressure. In such a case, the thrust on the inner face of the diaphragm moves the washer 39 away from the base 38 kept stationary with the rod 37 abutting against the bottom of the cap 35 and the gas can escape along the rod 37,'possibly through notches provided in the washer 39.

According to another feature of the invention, there is provided, upstream from the valve 32 and, for instance, at the entrance to the duct30, a calibratedport 50, so designed that when the pressure inside the cylinder has dropped below a certain value, the output at the outlet from the valve is so reduced that the diver, upon breathing in, feels a hindrance which warns him of the emptiness of the cylinder. The air reserve which corresponds to the Warning pressure should allow the diver to come up under normal conditions, from a maximum depth determined by the diameter of the calibrated port 50.,

Variously calibrated ports are provided in plugs 51, similar to carburettor nozzles and screwed into a tapping pro: vided at the entrance to the duct 30. When the diver, at a given depth, is warned, by the difiiculty he feels at breathing in, that he has reached a reserve pressure in his cylinder, he comes up and his difiiculty decreasesgin desired by the diver for coming up to the surface.

from a given depth. The removable nozzle described thus ofiiers the advantage that the diver may, should he so desire, increase or decrease the duration of this comingv up, from the moment he is warned. It is sutficientto choose a suitable nozzle.

What I claim is:

1. In a breathing apparatus for divers, in combination,

a closed hollow cylindrical body provided with a radially extending tubular portion, a flexible diaphragm for closing the cylindrical body, a valve-box'adapted to close the outer end of the tubular portion and to be connected to a source of a breathable gas under pressure, an inlet-valve in said valve-box'for controlling the breathable gas delivering into said tubular portion, means for operatively coupling said diaphragm and inlet-valve, an expiration valve located at the vicinity of the diaphragm and adapted to discharge outside the gas contained in the hollow body when its pressure is greater than the outer pressure, and

a mouth piece connected to the tubular portion at a point' of the tubular portion close by the inlet-valve and remote from the cylindrical body. e

2. In a breathing apparatus for divers, in combination, a hollow cylindrical body provided with a radially extending tubular portion, a rigid bell arranged in the cyline drical body, means for guiding said bell by allowing it to move along the axis of said cylindrical body, a flexible skirt having an edge secured to the side surface of the bell and the other edge secured to the cylindrical body so as to act as a diaphragm, a valve-box adapted to close the outer end of the tubular portion, and to be connected to a source of a breathable gas under pressure, an inletvalve in said box for controlling the breathable gas delivering into said tubular portion, means for operatively coupling the bell and inlet-valve, an expiration valve located at the vicinity of said bell and adapted to discharge outside the gas contained in the hollow body when its pressure is greater than the outer pressure, and a mouth piece connected to the tubular portion at the vicinity of the inlet-valve.

3. In a breathing apparatus for divers, in combination, a hollow cylindrical body provided with a radially extending tubular portion, a rigid bell arranged in the cylindrical body and provided with a rigid axial tube, a pin secured to the wall of the hollow cylindrical body and extending in said axial tube for guiding the hell by allowing it to move along the axis of said hollow body, a flexible skirt having an edge secured to the side surface of the bell and the other edge secured to the cylindrical body so as to act as a diaphragm, a valve-box adapted to close the outer end of the tubular portion and to be connected to a source of a breathable gas under pressure, an inlet-valve in said box for controlling the said gas delivering into said tubular portion, a lever extending through the tubular portion and interposed between the axial tube of the bell and said inlet-valve for operatively coupling said bell and inlet-valve, an expiration valve located at the vicinity of the bell and adapted to discharge outside the gas contained in the hollow body when its pressure is greater than the outer pressure, and a mouth piece connected to the tubular portion at the vicinity of the inlet-valve.

4. In a breathing apparatus for divers, in combination, a hollow cylindrical body provided with a radially extending tubular portion, a rigid bell arranged in the cylindrical body, means for guiding said bell by allowing it to move along the axis of said, cylindrical body, a flexible skirt having an edge secured to the cylindrical body so as to act as a diaphragm, a valve-box adapted to close the outer end of the tubular portion and to be connected to a source of a breathable gas under pressure, an inletvalve in said box for controlling the breathable gas delivering into said tubular portion, means for operatively coupling the bell and inlet-valve, an expiration valve provided on the bottom of the bell and adapted to discharge outside the gas contained in the hollow body when its pressure is greater than the outer pressure, and a mouth piece connected to the tubular portion at the vicinity of the inlet valve.

5. In a breathing apparatus for divers, in combination, a hollow cylindrical body provided with a radially extending tubular portion, a rigid bell arranged in the cylindrical body and provided with a rigid axial tube, a pin secured to the Wall of the hollow cylindrical body and extending in said axial tube for guiding the bell by allowing it to move along the axis of said hollow body, a flexible skirt having an edge secured to the side surface of the bell and the other edge secured to the cylindrical body so as to act as a diaphragm, a valve-box adapted to close the outer end of the tubular portion and to be connected to a source of a breathable gas under pressure, an inletvalve in said box for controlling the breathable gas delivering into said tubular portion, said inlet-valve being provided with a stem extending outside the valve-box in the tubular portion a lever provided at on end with an apertured heel mounted on said stem between a collar of the latter and said valve-box, and having its opposite end fork shaped for engaging a groove in the bell axial tube so as to operatively connect said bell and inlet-valve, an expiration valve provided on the bottom of the bell and adapted to discharge outside the gas contained in the hollow body when its pressure is greater than the outer pressure, and a mouth piece connected to the tubular portion at the vicinity of the inlet-valve.

References Cited in the file of this patent UNITED STATES PATENTS 59,529 Rouguayrol Nov. 6, 1866 2,387,123 Deming Oct. 16, 1945 2,473,078 Strange June 14, 1949 2,485,039 Cousteau Oct. 18, 1949

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