|Publication number||US2596178 A|
|Publication date||May 13, 1952|
|Filing date||Oct 12, 1948|
|Priority date||Oct 12, 1948|
|Publication number||US 2596178 A, US 2596178A, US-A-2596178, US2596178 A, US2596178A|
|Original Assignee||Henry Seeler|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (5), Referenced by (27), Classifications (12)|
|External Links: USPTO, USPTO Assignment, Espacenet|
y 3, 1952 H. SEELER 2,596,178
PRESSURE RESPONSIVE REGULATOR Filed Oct. 12, 1948 2 SHEETS-SHEET 1 INVENTOR. .//f/V/ .5 154? May 13, 1952 H. SEELER Filed Oct. 12, 1948 'EIEI 2 SHEETS-SHEET 2 INVENTOR. HENRY 555 :5?
ATTORNE/ Patented May 13, 1952 UNITED STATES PATENT OFFICE' Claims.
(Granted under the act of March 3, 1883, as amended April 30.. 1928; 370 0. G. 757) The invention described herein may be .manufactured and used by or for the United States Government for governmental purposes without payment to me of any royalty thereon.
The present invention relates to a pressure responsive regulator or relay for use in oxygen demand breathing systems or analogous gas flow regulating systems.
The primary object of the invention is to pro-. vide an oxygen demand regulator in which the flow of oxygen is controlled by a valve which is actuated by means of the high pressure oxygen supply and in which the pressure actuating means is in turn made responsive to a pilot valve actuated through a diaphragm exposed on one side to breathing pressures, and on the other side to atmospheric pressures.
A further object of the invention is to provide an oxygen demand regulator of general application in oxygen demand systems and characterized by a control diaphragm subject to atmospheric pressure on one side and to breathing pressure on the other side, whereby the diaphragm may act through a secondary or control valve to operate a primary or oxygen flow valve to supply oxygen to a subject when he inhales and to out ch such oxygen when he exhales.
Another object of the invention is to provide an oxygen demand regulator for use at high altitudes and including means responsive to the decreased atmospheric pressures at high altitudes to increase the flow of oxygen to the subject relying on the regulator to supply oxygen.
Another object of the invention is to provide a sensitive oxygen demand regulator of compact form and including a secondary or control valve which fits within a main or primary valve in telescopic relation, and including a sensitive diaphragm adapted to actuate the control valve through a lever system and further including another diaphragm adapted to actuate the main valve to regulate the flow of oxygen to a face mask or other breathing appliance.
Another object of the invention is to provide an oxygen demand regulator including a secondary or control valve adapted upon actuation to cause operation of a main or primary valve to regulate the flow of oxygen and wherein the secondary and primary valves are each arranged to have no fluid pressure thereon tending to unseat the valves in the closed position.
Another object of the invention is to generally improve the efiectiveness and reliability of oxygen demand regulators for use with oxygen demand breathing systems.
The above and other objects of the invention will become apparent upon reading the following detailed description of the invention in conjunction with the accompanying drawings, in which:
Fig. 1 is a vertical cross sectional view taken through one form of the present oxygen regulator and showing also the connection thereof to one form of face mask which may be used with the regulator.
Fig. 2 is atransverse cross sectional view taken on the line 2-2 of Fig. 1.
Fig. 3 is a vertical cross sectional view taken through another form of oxygen regulator embodying certain refinishments over the device of Fig. 1.
In oxygen demand breathing systems there is usually provided some means to regulate or meter the flow of oxygen to the breathing mask or apparatus. If the regulator is made responsive to periodic reduction of pressure inside the mask then it may be made to increase the flow of oxygen in accordance with the reduced mask pressure and thus supply oxygen when there is .a demand for it. This type of control system results in conservation of the oxygen supply and also ensures a minimum of discomfort and effort during breathing. Such a system-including also means to utilize air as well as oxygen for breathing, is disclosed and claimed in my copending application Serial No. 50,343, filed September 21, 1948, and entitled Oxygen Demand Breathing System Including Means For Altitude Regulation, which has matured into Patent No. 2,552,595 oi May 15, 1951. The uses and functions of the present regulator will be explained as the description proceeds but the constructional features of the regulator will be stressed especially.
Considering first the regulator or demand relay of Fig. 1 it is seen that the housing of generally circular shape comprises the upper and. lower housing elements I and 2, with the upper element threading into the lower at 3. An internal shoulder of the housing element 2 receives a thin flexible diaphragm 4, which is .clamped in place by the upper housing element I as shown. This diaphragm is preferably made of a high- ,strength rubberized texile fabric about 0.015 of an inch thick and in one example of the present regulator is only one and one-half inch in diameter. The diaphragm 4 divides the housing interior into an upper or aneroid chamber and a lower or control chamber. The upper chamber is open to the atmosphere by way of holes 5 in the housing element I. Centrally located on the upper wall of the housing element l is a boss 6 apertured and tapped to receive a threaded stem I, which may be adjusted vertically and. then looked in any adjusted position by means of a lock nut 8. The stem 1 carries an aneroid bellows 9 having a spring support II) on its lower end face. Extending between the support I and the center of the diaphragm 4 is a light spring II under compression. On the underside of the dia phragm 4 there is a central pressure plate I2 contacted by a lever I3 pivoted to the housing at I I. Near its pivoted end the lever I3 contacts one end of a second lever I5, which is pivoted at I6 to a bracket I6 secured to the housing element 2. The inner end of the lever I extends to the central axis of the regulator structure where it connects, with a control or pilot valve II, which has a stem loosely fitting a hole near the end of the lever I5.
Secured within the housing element 2 by means of a threaded ring I8 is a second diaphragm Ill, which is considerably thicker and less sensitive than the control diaphragm i. A suggested thickness for the diaphragm I9 is 0.08 of an inch and as before it may also be made of a rubberized textilesheet material. Centrally the diaphragm I9 is apertured to receive a sleeve 26 forming the upper portion of an oxygen supply valve 20. The diaphragm I9 and the sleeve are clamped in assembled relation by means of a clamping ring 2! threaded over the upper end of the sleeve 20'. Threaded into the upper end of sleeve 20 is a valve guide 22, in which the control valve [1 is slidably mounted. The lower end of valve I'I. carries a poppet element and situated between the poppet and the valve guide 22 is a coil spring 23 tending to hold the valve II in closed position. To prevent leakage between the valve I! and the'valve guide 22, there is provided a rubber band 24 encircling both the stem of valve I1 and a downwardly extending portion of guide 22. Gas pressure withinthe valve 20 serves to maintain the sealing action of the band 24 but the band is normally under tension in any case, whether there is fiuid pressure in the valve or not. Through the walls of sleeve 20' there are provided several passages 25 opening into a thin chamber below diaphragm I 9, whereby pressure may be aplied to lift the diaphragm and the oxygen supply valve 20. Furthermore the primary valve chamber or pilot chamber below the diaphragm I9 is open to the atmosphere by a pinhole passage 26 to allow the pressure in the chamber to return to atmospheric when flow through the passages 25 has stopped. The pilot valve I1 and oxygen supply valve 20 may be termed the secondary oxygen valve and the primary oxygen valve respectively.
The main portion of valve '29 is provided with a central valve passage 21 the upper end of which provides a seat for the poppet element of valve I'I. Secured in thelower end of valve 25! is gasket 23 "Whichls also apertured in alignment with the passage 21. The gasket 28 is adapted to contact the valve seat 29 provided on the bottom wall of an. oxygen supply chamber 30. The enlarged lower end of the valve 20 is guided within the chamber 30 but has four sides cut away to provide oxygen supply passages, as best shown in Fig. 2. The central portion of valve 29 is guided by means of a bushing or guide 3| fixed in the housing element 2. A compression spring -32 is in contact both with the guide 3| and the enlarged lower end of the valve 20. In engagement with a portion of the guide 3| and the central portion of the valve 20 is a rubber sealing band 33, which functions just like the band 24 described above.
Extending through the bottom wall of the chamber 30 is an oxygen passage 29' opening centrally of the valve seat 29 into the chamber 30. The oxygen passage 29' and the gas receiving spaces therebelow may be termed the gas inlet chamber.
The lower end of the housing element 2 is provided with a cylindrical recess to receive a porous filter 34, which is held inposition by a coil spring 35 and a threaded retaining ring 35. An extension of the housing element below the filter chamber provides a fitting element 3'! of any desired form for attachment to an oxygen bottle or conduit. The filter 3 3, which is recessed centrally at 34, acts to strain out dust or foreign matter which might be harmful to the regulator mechanism especially if it lodges on the valve seats. The filter may be made of various porous materials, such as ceramic or metallic materials. The porous metal filters, which are preferred for their durability, are made by sintering a mass of powdered metals which braze themselves into a metallic network porous enough to pass oxygen gas and filter it free of foreign matter. Such a metallic filter might be produced in accordance with the principles set out in U. S. Patent No. 2,297,817 granted to Clyde W. Truxell et al. on October 6, 1942. In direct communication with the oxygen supply chamber 30 is an oxygen supply fitting 38 and in communication with the control chamber is another fitting 39. These fittings are adapted to have rubber connecting tubes secured thereto.
To disclose the preferred use for the present regulator or relay, Fig. 1 illustrates an oxygen demand system similar to that of my copending application referred to above. As indicated in Fig. 1 the fittings 38 and 39 of the oxygen regulator are connected to a pair of thin flexible tubes es and III respectively, which lead to a face mask 42 worn by a subject 43. Thus the tube 40 carries pure oxygen from the regulator to the mask, and the tube II transmitsgas pressure to the control chamber of the regulator for effecting a cyclic control action on the fiow of oxygen to the mask. The mask 42, which covers both the nose and mouth, is fastened securely to the face of subject 43 by straps passing around the head. In the front wall of the mask is an air inlet valve 44 which is responsive to reduced pressure inside the mask to open and allow air to be taken, in for mixing with oxygen during inhalation phases of the breathing cycle. The inlet or inhalation valve M comprises a flexible flapper element 44 normally seated on .a circular valve seat but adapted to move away from the seat when the pressure in the mask is negative, that is below the atmospheric pressure. Thus during inhalation the sudden reduction of pressure inside the mask causes valve 44 to open and thus permits air to enter the mask. The mask wall also carries an exhaust or outlet valve 45 which is responsive to increased pressure inside the mask to open and allow the products of respiration to be expelled during exhalation phases of the breathing cycle.- The valve 45 includes a thinrigid disk 46 normally held against a circular valve seat by-means ,of a coil spring 41. In Fig. 1 the inlet or inhalation valve 44 is shown in open position and the outlet or exhalation valve is shown in closed position. Thus at the instant depicted the subject 43 isinhaling and is drawing air from the free atmosphere into the mask and this air may 'mix with pure oxygen flowing from the oxygentube 40 into the mask. Since air is about 21 per cent oxygen by volume, the air inhaled provides part of the oxygen requirements of the subject and helps to conserve his supply of pure oxygen accordingly.
Instead of the flapper-type of air inlet valve made of rubber or other flexible material it may be preferred in some instances to use other forms of sensitive valve devices, such as the disk-andspring type of valve similar to the outlet valve 45. Since the gas pressures inside the mask are kept very low, the inlet and outlet valves are made to respond to small pressure differentials accordingly. For example the critical pressures for these valves may be five millimeters of water for the inhalation valve 44 and twenty millimeters of water for the exhalation valve 45. These values of pressure response are only stated by way of example but in any case it is understood that the pressure as stated for the inhalation valve refers to a pressure inside the mask below atmospheric, While the pressure as stated for the exhalation valve refers to a pressure inside the mask above atmospheric.
The aneroid bellows 9, which affords altitude compensation or regulation and thus ensures an increasing supply of oxygen as the altitude increases, is a standard unit. This type of bellows is sealed up while in a vacuum and has enclosed within the bellows a coil spring. Under the pressure of sea level atmosphere the bellows will be compressed a maximum amount and as altitude is increased the bellows will expand in proportion to the increase in altitude. The spring within the bellows overcomes the bending resistance of the metal bellows walls, thus making the bellows more sensitive.
The operation of the system as shown in Fig. l
will be explained to show how the regulator functions to respond to the oxygen demand of the subject 43. For the first part of the explanation it is assumed that the system is in use at about 12,000 feet above sea level. The subject 43 may now inhale and the reduction of pressure inside the mask will immediately cause the air inlet valve 44 to open for admission of air into the mask. Simultaneously the pressure in the control chamber of the regulator will be reduced by virtue of the connecting tube 4|. With the pressure below the diaphragm 4 reduced, the air pressure on the upper side of the diaphragm will cause the control diaphragm to bulge downward- 1y to effect opening of the control valve l 1 by action of the levers l3 and [5. Now oxygen may issue from the passage 21 into the hollow valve and thence by way of the passages into the space below diaphragm I9. Since the oxygen pressure is much greater than the low pressure above the diaphragm I9, the diaphragm and the attached valve 2!! lift to thus open the oxygen supply valve and admit oxygen to the chamber 30. The oxygen now flows through the fitting 38 and tube into the mask, Where it mixes with the air flowing into the mask through air inlet valve 44. This mixing action is usually referred to as oxygen dilution but its purpose is to increase the proportion of oxygen in the air being breathed. At the moderate altitude under consideration the aneroid 9 is not expanded enough for the spring H to have any appreciable effect on the control diaphragm. Under the altitude condition stated, the gases inside the mask during inhalation phases will now be sufliciently enriched by oxygen to give a suitable breathing mixture. The air being at a reduced atmospheric pressure there will be less oxygen per unit volume than at low altitudes and an oxygen supplement will be necessary. Now when the subject exhales,
the valve 44 will close while the valve 45 will open to allow the products of respiration to be expelled into the atmosphere. Moreover the pressure increase inside the mask will be transmitted to the control chamber of the regulator and the control diaphragm 4 will be forced upwardly. With the downward pressure on lever l3 relieved, the spring 23 will cause the control valve I I to close, and the pressure under diaphragm [9 will soon be reduced to atmospheric because of the bleed passage 26. The coil spring 32 will now act to close the oxygen supply valve 20 and thus conserve the oxygen which is available in limited quantity. From the description of operation it will be seen that air is used to as great an extent as possible but is diluted with oxygen as the demand therefor is made to operate the regulator. Using the oxygen only as a supplement helps to conserve the limited supply which is carried on the aircraft. During exhalation phases of breathing the regulator acts to close the oxygen valve and prevents further flow of oxygen while there is no demand therefor. It is further noted that the regulating action of the device does not involve high pressures, because of the relay principle embodying the pilot valve I1 and the thin diaphragm for actuating the valve by way of levers I3 and H3. The oxygen pressure available is used to open the supply valve 20 and is thus used to good advantage in opening the main valve in accordance with concurrent action of the pilot or control valve IT. The subject is therefore able to regulate the cyclic flow of oxygen merely by exerting normal inhalation and exhalation pressures, which in turn efi'ect control of the oxygen valve 20 by means of the diaphragm 4 and the pilot valve H. The valve ll by its relay action thus controls the flow of oxygen to the high-pressure chamber below the valve actuating diaphragm l9. Furthermore the ele ments which must be actuated by the thin diaphragm 4 are light in weight and therefore have little inertia to retard their action. A further advantage inherent in the present regulator is that the device may be made small in size and light in weight. The size may be gagedi by the fact that in one completed regulator the control diaphragm 4 is only one and one-half inch in diameter.
Considerin now the action of the oxygen demand system and regulator at a considerable altitude, for example about 22,000 feet above sea level, it is first noted that the aneroid bellows S will. be slightly elongated compared to its length as in the previous example. Now the coil spring it will be compressed to a greater extent than before and the resultant increased force exerted on the control diaphragm 4 and on the levers l3 and [5 will act to hold the control valve ll slightly open even though the sube t 413 is not inhaling nor exhaling at the moment. With the valve I! open the pressure build-up in the pressure chamber under diaphragm H3 will act to hold the oxygen supply valve 2:; off the valve seat 29 and thus allow oxgyen to flow through the chamber ti) and tube as into the face mask 42. Now when the subject inhales, the reduced pressure in the control chamber will cause the diaphragm 4 to move downwardly still farther under the force of spring H and atmospheric pressure acting on top of the diaphragm. The response of levers l3 and i5 and valve I! will cause a more definite elevation of the oxgyen supply valve 20 and a consequent plentiful supply of oxygen to the face 7 mask through. the tube 40.7 The tube 40 acts also to reduce the pressure of oxy en as delivered to the mask. While the oxygen pressure in the chamber 30 may be considerable, the throttling effect of the supply tube 40 and the'large volume available in the mask and lungs of the subject ensure that the mask pressures will not be excessive. With the present system a suggested initial pressure at the neck of the oxygen bottle is 400 pounds per square inch. Oxygen is usually supplied from a bottle or cylinder of the compressed gas although it is possible to use liquefied oxygen or an oxygen generator. At the higher altitude under consideration presently the air inlet valve 44 will open duringinhalation but will not open fully nor for all of the time taken up by the inhalation phase, since there is a slightly increased pressure inside the mask due to the more pronounced opening of the oxygen supply valve 20. Thus the proportion of air inside mask will be less than at the lower altitude discussed above. For example at 22,000 feet the mask contents during inhalation may be 80 per cent pure oxygen and 20 per cent air. Thus it is seen that as the altitude is increased and the air inlet valve 44 opens less, the extent of oxygen dilution of the air being breathed will be increased in proportion' Upon exhalation the valves l1 and 20 will close, by reason of the pressure increase within the control chamber of the regulator. When thefpilot valve I? closes and oxygen no longer can reach the chamber under diaphragm iii, the pressure therein will be reduced to atmospheric by reason of the bleed passage 26.
Operation of the regulator at extreme altitudes, for example at 35,000 feet above sea level, differs from that explained above mostly in the furtherelongation of the aneroid bellows 9 and the further compression of the coil spring ll. Under these conditions of reduced atmospheric pressure the force of the spring II is the main influence in opening thec-ontrol valve H. The lack of atmosphericpressure on the upper side of the control diaphragm 4 as well as the higher pressures under the diaphragm due to increased oxygen flow will mean that during inhalation the diaphragm 4 will not have any marked tendency to bulge downwardly. The main force effective in opening the control valve l1 and the oxygen valve 20 will be the bellows 9' and the spring H and it should be noted that this will be a constant force at a constant altitude. This actuating force now being at a maximum, the assisting forces or the counter forces will not have much effect unless they too are increased in magnitude. However since these forces developed during the breathing cycle by the action of the subject will not increase materially at higher altitudes, the bellows is the main factor at the extreme altitudes. Because of the bellows action the valves I1 and 20 will now be held open at all times except during exhalation, and
as a result the pressure inside the mask will tend to increase from the influx of pure oxygen from the regulator. The subject may now inhale with less effort and the inhalation phases will not bring about any opening of the air inlet ,valve e4. Thus he will now be breathing pure oxygen at all times. As he exhales there will be an increase in gas pressure inside the mask and the outlet or exhaust valve 45 will open to release most of the expelled respiration products. The pressure increase will be transmitted to the control chamber of the regulator by means of the tube 4| and the diaphragm 4 will accordingly bulge upwardly. The resulting action will cause the control valve [1 to seat and thereby cause seating of the oxygen supply valve 20. Thus as the demand is removed the oxygen supply is cut off and oxygen thereby conserved for the inhalation phases of breathing.
In passing it is noted that there are varying pressures on the opposite sides of the diaphragm I9 but they are of such differences in magnitude that variations in pressure above this diaphragm during the breathing cycle may be ignored entirely. The only important consideration as far as the operation of the diaphragm I9 is concerned is the rise and fall of'the oxygen pressure under the diaphragm as the control valve I1 is opened and closed. Also while the control chamber is connected to the mask by tube 4| the tube has some pressure reducing effect, but in any case the control pressure will always be in direct proportion to the pressure inside the face mask 42.
One possible breathing system has been described abcve using the present regulator, but there are other possible systems where the regulator may be equally effective. For instance the system of Fig. 1 may be modified by omission of the air inlet valve 44. Such a system would operate quite well as an oxygen demand breathing system where no outside air is to be used. A system of this type might be used in high altitude flying to supply oxygen to aircraft personnel or it might be used Where the-outside air is contaminated by fumes or dust, such as in unsafe mines or in case of air pollution by gas, smoke or dust. Therefore it should be understood that the regulator as disclosed, as well as similar forms of the device, are adapted for usein a variety of situations and with a variety of associated devices such as masks, inhalators and helmets. While the regulator has been described and illustrated as though it were always maintained in a vertical position, it should be understood that operation will be satisfactory in other positions thereof. In fact when in use on aircraft it must function during various flight maneuvers and must be able to withstand sudden changes in position and still continue to function.
For a detailed description of a second regulator embodying certain refinements and advantages over the device of Figs. 1 and 2 reference is made to Fig. 3 of the drawings. In the second form of the regulator a housing is provided which is of circular shape in cross section and made up of upper and lower housing elements 5| and 52, with the upper element threading into the lower at 53. An internal shoulder of the housing element 52 receives a thin flexible'diaphragm 54, which is clamped in place by the upper housing element l as shown. This diaphragm is of highstrength rubberized textile fabric like the diaphragm 4 of Fig. 1. Also clampedin place over the diaphragm in contiguous relation thereto is a thin metal disk or safety plate 54' having a central circular opening therein. The diaphragm 54 divides the housing interior into an upper or aneroid chamber and a lower or control chamber.
The upper chamber is open to the atmosphere by way of holes 55 in the housing element 5|. Centrally located in the upper wall 'ofthe housing element 5! is a tapped opening 56 which receives a threaded stem- 5?. The stem 51 may beadjuSted vertically and then locked in place by means of a lock nut '58. The 'stem 51 carries an'aneroid bellows 59 having a spring support 60 on its lower end face. Extending between the support 60 and the center of the diaphragm is a light coil spring (H, which bears on a circular plate 6| cemented to the diaphragm. On the underside of the diaphragm 54 there is a central pressure plate 62 having an outside diameter greater than the diameter of the opening in safety plate 54. The pressure plate 62 contacts a lever 63 which is pivoted at 64 to a fixed support 66. The lever 63 contacts another lever 65 which is pivoted at 66' to the support 66. The inner end of the lever 65 extends to the central axis of the regulator structure where it connects with a control or pilot valve 61, which has a stem loosely fitting a hole near the end of the lever 65.
Secured within the housing element 52 by means of a threaded ring 68 is a second diaphram 69, which is considerably thicker and less sensitive than the control diaphragm 54. Centrally the diaphragm 69 is apertured to receive a flanged cup 10, secured to the diaphragm by a threaded clamping ring H. Threaded into the cup 70 is the valve member 72 having connected thereto an oxygen valve 13 carrying a seating gasket 73' on its lower end. Between the top wall of cup l and the upper end of valve member 72 there is a valve guide 14, and extending between the guide and the enlarged lower end of pilotvalve 61- is a coil spring 15. A rubber sealing band is also employed in a manner similar to the band 24- of Fig. I, so as to prevent gas leakage around the stem of valve 61. A seat for the valve 67 in the member f2 opens into passages 16 extending laterally in. a thin chamber under the diaphragm 69. The chamber in turn opens to the atmosphere by way of a pinhole 11, for permitting the pressure to return to atmospheric after oxygen flow into the chamber is cut off. The valve 13 has a central passage therein opening laterally at T8 to the oxygen chamber 79. At the upper end of this central passage there is a recess which connects by passages 80 to the interior of valve member 12, in order to complete the passage for oxygen into the chamber under diaphragm 69 when the valve 61 is unseated. Of course the passages 16 and 80 are so located in valve member 12 that they do not intersect with each other. It is noted that the stem of valve 61 is the same diameter as the seat for the valve and therefore with the pilot valve closed the oxygen pressure will be'distributed around the valve evenly and there will be no force from the gas pressure tending to open the valve. Once the valve is opened by action of the diaphragm 54, lever 63 and lever 65 there will be some endwise gas pressure tending to hold the valve open. This force is opposed by the spring 75 so that the gas pressure is thus resisted by a force that increases as the valve opens farther. In any event the spring 75 will be made strong enough to close the valve 61 as soon as the actuating force of the diaphragm and levers is diminished.
The oxygen valve 13 is guided by contact between the lower end portion and the walls of chamber I9 and also by means of a guide member 8| held in place by a threaded clamping ring 82. Between the guide member BI and the lower end portion of the valve 13 there is a coil spring 83 tending to close the valve. The disk '84 under the valve carries a valve seat 35 having the same diameter as the stem of valve 13. The disk 84 is held in position as shown by a fitting 86 threaded into the housing element 2 and also retaining a screen 81 in place to prevent entry of foreign matter, particularly during shipping of the regulator. The fitting 88 is shaped on its free end for retaining a flexible tube to conduct oxygen to the face mask. Another fitting 81 threaded into housing element '52 is shaped to retain a flexible tube leading to the face mask. These tubes are not shown but it is understood that they would correspond with the tubes 40 and 4| of the oxygen demand system shown in Fig. 1.
Threaded into the housing element 52 is a third fitting 88 for connection with a source of pure oxygen gas under pressure. At the inner end of the fitting 88 is a. gas filter '89 similar to the filter 34 of Fig. 1. To holdthe filter in position without placing it under excessive strain a coil spring 90 is provided as shown. A recess 89- at the inner end of the filter registers with an opening 9| leading into the oxygen chamber 19.
Attention is again directed to the fact that the valve seat 85' has the same diameter as the stem of oxygen valve 13. Therefore in the closed position of the valve the oxygen gas pressure in the chamber 19 will be evenly distributed around the valve 13 so as to exert no initial opening pressure. The valve when closed will thus be stable and not have a tendency to open itself with every jar or change in position of the regulator. As explained with respect to the pilot; valve 61, the valve 13 after being opened has more gas pressure thereon in an opening direction than in a closing direction. However on opening the spring 83 is compressed more and tends toovercome the opening pressure of the gas. It should be understood that the spring 83 must be strong enough to close the valve 13 once the oxygen pressure under the diaphragm 69 has been reduced to atmospheric by closing of the pilot valve 61.
The operation of the regulator or pressure relay as shown in Fig. 3 is similar in all essential respects to the regulator of Fig. 1. Assuming the regulator of Fig. 3 to be connected in an oxygen demand breathing system as in Fig. 1, with fittings 85 and 81 being connected. to the face mask and fitting 88 connected to oxygen gas under pressureno oxygen will be flowing into the mask. However if the subject inhales the reduced pressure in the mask and in the control chamber of the regulator will cause the diaphragm 54 to bulge inwardly under the pressure of spring 6| and also the pressure of the outside atmosphere. Therefore the levers 63 and will be actuated to lift the pilot valve 61. Oxygen under pressure will now flow through passages into the valve member 12, thence past the valve seat into the passages 16 and into the chamber under the diaphragm 69.. This pressure will now lift the diaphragm and parts fixed thereto thus opening the oxygen valve 13 and allowing oxygen to flow past the valve seat into the fitting 86 leading to the face mask. On exhalation the pressure in the control chamber rises, pushing the control diaphragm 54 upwardly and allowing pilot valve 61 to close under the action of coil spring 15. The pressure under diaphragm 69 now drops to atmospheric because of the bleed passage 11 and as a result the oxygen valve 13 closes under the action of coil spring 83.
The action of aneroid bellows 59 in producing greater flow of oxygen at higher altitudes has already been explained at some length in com nection with Fig. 1 and need not be repeated. It is noted however that when the atmospheric pressure is reduced and the control diaphragm 54 tends to bulge upwardly because of higher mask pressure and exhalation pressures, then the diaphragm will be protected from possible 11 rupture by the safety plate 54. While this plate may be made of thin metal, it is also possible to use a stiff fiber sheet or laminated plastic material which will yield slightly and still not allow the diaphragm to balloon upwardly. It is understood that the stem portions of valves 61 and 13 are sealed against leakage where they move in the stem guides by rubber bands as illustrated or by any other suitable or expedient means available. The rubber band sealing means has been found to have advantages, since gas pressure around the stem tends to press the rubber tight against the contacting elements. The stems need not slide with respect to rubber bands, since a limited movement merely results in a flexing of the rubber whereby the bands or sleeves shorten up and bulge outwardly in the middle portions thereof.
The advantages and operating results attributed to the regulator of Fig. 1 in the detailed description thereof are also inherent in the regulator of Fig. 3, but in addition the latter device has special features of construction as already described. In particular the regulator of Fig. 3
possesses the balanced valves 61 and 13 having no, gas pressure tending to open the valves once they are in the closed positions thereof. Another important feature is the protective ring or plate 54 on top of the thin diaphragm 54 and having an inside diameter less than the outside diameter of the pressure plate 62 under the diaphragm. It is also to be noted that in both regulators described the complete devices are compact and comparatively simple in construction. By mounting the pilot valve or secondary valve inside of the main valve or primary valve a reliable and compact arrangement is provided, which has the further advantage of symmetry with respect to the central axis of the regulator. Moreover by applying the pilot valve or pressure relay principle to the actuation of the oxygen supply valve, the control diaphragm which is responsive to breathing pressures may be made small in diameter. At' the same time demand control over the oxygen supply valve may be exerted by the normal breathing pressures within the mask. The person wearing the mask will not be required to work against cumbersome and unwieldy control devices in order to exert demand control over the oxygen supply. Thus one serious objection to some demand control devices is entirely eliminated. The present regulators, while being quite sensitive for reasons explained above, are also thoroughly reliable and easy to maintain in good working condition.
The embodiments of the invention herein shown and described are to be regarded as i1 lustrative only and it is to be understood that the invention is susceptible to variations, modifications and changes within the scope of the appended claims.
1. An oxygen demand regulator for operative association with a face mask and a container of oxygen under pressure, said regulator comprising a main housing, a control diaphragm extending across said'housing for actuation by the fluid pressure inside the face mask acting on one side of said diaphragm in opposition to atmospheric pressure acting on the other side of said diaphragm, a second diaphragm in said housing providing a'supply valve actuating chamber at one side of said second diaphragm, means providing a narrow passage from said supply valve actuating chamber to the atmosphere, a pilot 12 valve housing extending through and fixed to said second diaphragm centrally thereof, an extension at one end of said pilot valve housing having a poppet on its free end, a circular valve seat in said main housing connectible to said container of oxygen and cooperating with said poppet valve to provide an oxygen supply valve, an annular oxygen supply chamber within said main housing surrounding said extension and having a passageway opening therefrom for connection with the face mask, a pilot valve movably mounted in said pilot valve housing and cooperating with a pilot valve seat at said one end of said pilot valve housing, passage means extending through said extension from said pilot valve seat for conducting oxygen from said container to said pilot valve, a wall of said pilot valve housing having therein a passageway leading from said pilot valve housing to said supply valve actuating chamber, lever means extending from said control diaphragmto said pilot valve for unseating said pilot-valve by movement of said control diaphragm resulting from inhalation of the person wearing the face mask, whereby oxygen is admitted to said pilot valve housing and to said supply valve actuating chamber to thereby unseat said poppet valve by pressure exerted on said second diaphragm to thus supply oxygen to said oxygen supply chamber and to said face mask.
2. An oxygen demand regulator for operative association with a face mask and a container of oxygen under pressure, said regulator comprising a main housing, a control diaphragm'extending across said housing for actuation by the fluid pressure inside the face mask acting on one side of said diaphragm in opposition to atmospheric pressure acting on the other side of said diaphragm, a second diaphragm in said housing providing a supply valve actuating chamber at one side of said second diaphragm, means providing a narrow passage from said supply valve actuating chamber to the atmosphere, a pilot valve housing secured to said second diaphragm centrally thereof, a poppet valve rigidly connected to said pilot valve housing, a circular valve seat in said main housing and cooperating with said poppet valve to provide an oxygen supply valve, means providing an oxygen passage for connection from said container to one side of said oxygen supply valve, meansproviding an oxygen passage from the other side of said oxygen supply valve to a face mask connection on said housing, a pilot valve movably mounted in said pilot valve housing and cooperating with a pilot valve seat at one end of said pilot valve housing, passage means for conducting oxygen from said container to said pilot valve seat, a wall of said pilot valve housing having therein a passageway leading from said pilot valve housing to said supply valve actuating chamber, means extending from said control diaphragm to said pilot valve for unseating said pilot valve by movement of said control diaphragm resulting from inhalation of the person wearing the face mask, whereby oxygen is admitted to said pilot valve housing and to said supply valve actuating chamber to thereby unseat poppet valve by pressure exerted on said second diaphragm.
3. An, oxygen demand regulator for operative association with a'face mask and a container of oxygen under pressure, said regulator comprising a housing, a circular control diaphragm extending across said housing on the interior thereof and providing an aneroid chamber at one side and a control chamber at the other side of said diaphragm, a fiat ring in contiguous and concentric relation with respect to said one side of said diaphragm and having its marginal edges fixed to said housing, said aneroid chamber being open to the atmosphere and having mounted therein an aneroid bellows and a compression spring in series with the spring also. continuously pressing on said diaphragm, means for making a connection through a wall of the housing from said control chamber to said face mask, means including a second diaphragm for providing a primary valve actuating chamber in said housing, means providing a narrow passage from said primary valve actuating chamber to the atmosphere, a secondary oxygen valve in said housing to admit oxygen under pressure to said primary valve actuating chamber, actuating means for said secondary oxygen valve including said control diaphragm, a primary valve actuating means including said second diaphragm responsive to changes in pressure in said primary valve actuating chamber, and a primary oxygen valve in said housing including a movable element attached to said second diaphragm and operable when open to allow flow of oxygen into a portion of said housing having an oxygen outlet opening therefrom.
4. An oxygen demand regulator for operative association with a face mask and a container of oxygen under pressure, said regulator comprising a housing, a control diaphragm extending across said housing on the interior thereof and providing an aneroid chamber at one side and a control chamber at the other side of said diaphragm, said aneroid chamber being open to the atmosphere and having mounted therein an aneroid bellows and a compression spring in series for continuous contact with said diaphragm, means for making a connection through a Wall of the housing from said control chamber to said face mask, means providing a primary valve actuating chamber in said housing, means providing a narrow passage from said primary valve actuating chamber to the atmosphere, a secondary oxygen valve in said housing to admit oxygen under pres sure to said primary valve actuating chamber, actuating means for said secondary oxygen valve including said control diaphragm, a primary valve actuating means responsive to changes in oxygen pressure in said primary valve actuating chamber, a primary oxygen valve in said housing actuated by said primary valve actuating means and operable when open to allow flow of oxygen into a portion of said housing having an oxygen outlet opening therefrom, and means for conducting oxygen under pressure from said container to said secondary and primary oxygen valves.
5. In a gas demand regulator for regulating the flow of gas to a face mask, a housing including a gas inlet chamber connected at all times to a source of gas under pressure, means at one end of said chamber providing a circular valve seat, conduit means leading from said valve seat and through a wall of said housing to provide a connection leading to said face mask, a poppet valve in said chamber having an enlarged poppet end portion for valve closing abutment at one side thereof with said valve seat to prevent flow of gas from said chamber into said conduit means, a cylindrical valve stem extending from said poppet end portion at the opposite. side thereof and through sai chamber for connection with valve actuating means, apertured wall means at the other end of said chamber to slidably receive and guide said valve stem, a coil spring on said valve stem between said apertur'ed wall means and said poppet end portion'for biasing said pop-pet valve toward seated position, cylindrical flange means extending from said apertured wall means around the valve stem guiding aperture therein, an elastic sealing band encircling said cylindrical flange means and a portion of said valve stem adjacent thereto, and said valve stem having a diameter substantially equal to the diameter of said valve seat, whereby the gas pressure against said poppet end portion adjacent to said valve seat and radially outward therefrom when the valve is closed is equalized by the gas pressure against said poppet end portion adjacent to said valve stem and radially outward therefrom.
REFERENCE S CIT The following references are of record in the file of this patent:
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|U.S. Classification||128/204.28, 137/81.1, 128/204.29|
|International Classification||A61M16/20, A62B9/00, A62B9/02|
|Cooperative Classification||A61M16/20, A62B9/027, A62B9/022|
|European Classification||A61M16/20, A62B9/02D, A62B9/02D4|