US2646041A

US2646041A - Metering apparatus for oxygen tents

Info

Publication number: US2646041A
Application number: US217201A
Authority: US
Inventors: Gilroy John; Jr Arthur R Wiese
Original assignee: Air Reduction Co Inc
Current assignee: Airco Inc
Priority date: 1951-03-23
Filing date: 1951-03-23
Publication date: 1953-07-21
Anticipated expiration: 1970-07-21

Description

July 21, 1953 J. GILROY ETAL METERING APPARATUS FOR OXYGEN TENTS Filed March 23, 1951 ERS FER HIN v INVENTORS JOHN GILROY YARTHUR R. wussz m.

ATTORNEY ratus under normal conditions.

Patented July 21, i953 L were UNITED STATES PATENT OFFICE METERING APPARfiATgS FOR OXYGEN John Gilroy, Sun Prairie, and Arthur R. Wiese, Jr., Madison, Wis., assignors to Air Reduction .Company, Incorporated, a. corporation of New York Application March 23, 1951, Serial No. 217,201

4 Claims.

ratus be quickly and simply operated for such use.

In apparatus for delivering oxygen to hospital oxygen tents, for instance, the oxygen is normally metered'into the tent in a range of relatively low gas flows suflicient to meet the demands of the patient. However, the tent enclosure containing the isolated atmosphere breathed by the patient must first be purged to bring the oxygen content to the'required concentration before the tent is ready for use; and it is desirable to eiiect the purgingat a relatively high rate of flow to save the time and effort of the attendant. Usually, valve "connections of a suitable character are provided to permit oxygen to be delivered into the tent at precisely controllable rates, meeting the needs of the patient and also at higher rates for purging the tent preparatory to' its use; e

For safe and efiicient operation, such valve means should be simple to manipulate and capable of rapid adjustment to deliver the gas in a normal flow range or at considerably higher flow rates above such a range. V

Oneof the objects of this invention is to provide an improved metering apparatus for medical oxygen tents.

Another object of this invention is to provide a combined metering and flushing valve of improved'construction for use in such gas metering apparatus, having a single control for selectively operating the valve in a range of relatively low, precisely adjustable gas flows, or in a range of Another object of the invention is to provide a valve wherein the delivery of the high or flush rates of gas flow occurs immediately and automatically substantially when the valve is adjusted for the maximum rate of flow in the metered low flow range of normal use; and substantially without additional manipulation of the valve control means or a separate controladjustment.

Another object of the invention isto provide is adapted to be used in a gas metering apparatus assembly including a flow measuring instrument of the Bourdon gage, or pressure type.

A further object is to provide a valve having an improved construction particularly adapted to simplify maintenance and repair during service. r i a A still further object is to provide a valve of simple and inexpensive construction.

Other objects and advantages will be apparent from the specification and claims, andfrom the accompanying drawing which illustrates a preferred embodiment of the invention.

In the drawing,

Figure 1 is an assembly view showing a pressure regulating device and an improved metering valve attached thereto which are operatively connected to a hospital oxygen tent that is schematically illustrated in the drawing,

Figure 2 is an enlarged sectional View of the metering valve included in the assembly of Figure 1, and i Figure 3 is a sectional view of a portion of the metering valve taken along the line 33 in Figure 2.

In accordance with the preferred embodiment of the invention, apparatus for delivering gas at larged opening in by-pass relation thereto, and

a valve member normally closing the enlarged bypass opening which is adapted to be opened by the pressure of the gas acting thereon, at a predetermined rate of gas flow through the metering orifice.

Referring to the drawing, an oxygen tent hood is shown schematically at [0 which is made of some suitable transparent material, such as a clear Vinylite plastic, suspended above a hospital bed H by conventional apparatus so that the lower endsof the hood maybe tucked under the bed mattress to form an enclosure. The oxygen tent may be, for example, the one disclosed in the co-pending application of J. Gilroy and P. Eckman, Serial No, 217,202, filed March 23, 1951, entitled Oxygen Tent, and assigned to the assignee of the present application; or it may be substantially similar to the apparatus shown and described in Patent No. 2,104,589, issued J anuary 4, 1938, for Refrigerating Apparatus. Such tents comprise a bedside base for suspending the tent hood over the bed, air conditioning apparatus for circulating and cooling the atmosphere within the enclosure formed by the tent hood, control devices therefor, and means for receiving and controlling the administering of oxygen into the tent enclosure to meet the needs of the patient. In the present apparatusoxygen is supplied from a source such as the oxygen cylinder !2 which receives the inlet connection !3 of a pressure regulating device it. The regulating device is connected through its outlet boss to a metering valve is secured therein. Oxygen is delivered therefrom at a desired rate of flow through a hose H which is received over the nut 36 and the back of the valve seat at the terminal end of upper chamber 30 whereby the enlarged head of the valve stem is drawn into seated engagement with the valve seat around the lower opening of passage 3i. The sectional view ofFigure3 illustrates the shape of the nut 36 which is square so that spaces 36' are created between the longitudinal faces of the nut and the wall of the chamber 30 through which gas may pass around the nut to the valve outlet. A slot 31 is formed in the enlarged head portion at the lower end of the valve stem 32 which may be engaged by a tool such as a screw-driver for the outlet of the metering valve at one end and entering directly into the tent hood ii! at its other end. It will be understood, however, that the oxygen delivery hose I? would in most instances be received in some other portion of the oxygen tent apparatus such as in the air conditioning system from whence the oxygen would be administered to the tent enclosure instead of directly therein as illustrated, but such associated apparatus have not been shown since they form no part of the'present invention, and for the purpose of the present invention the oxygen may be introduced into the oxygen tent in any suitable manner.

The pressure regulator M consists of a device adapted to receive gas from a source which may vary in pressure and deliver the gas at a substantially constant pressure. It may be, for example, a device such as the pressure regulating device shown and described in Patent No. 1,948,027, G. M. Deming, for Compound Gas Pressure Regulator. Thus the regulator M has an adjusting handle l8 by which the regulating mechanism may be adjusted to produce a desired delivery pressure which is maintained substantially constant by the pressure responsive regulating mechanism. The rate of flow of the gas through the metering valve is indicated on a gage 19, which is a pressure responsive gage of the Bourdon type, secured in the regulator outlet boss, and calibrated to indicate the rate of flow.

The metering valve 16, shown in the enlarged sectional view of Figure 2, comprises an elongated valve body having a threaded portion 2l which is received in the outlet l5 of the pressure regulator. On the valve body a hexagonally shaped section 22 accommodates a tool for tightening the engagement of the threads 2|, and a lower cylindrical portion 23 of reduced diameter receives the hose ll which slides onto such portion of the valve over the discharge outlet, forming a frictionally retained gas-tight connection between the hose and the valve.

A passage 25 extends through the valve body, opening at one end into a chamber .26 in the regulator outlet 15 and terminating at its other end in a discharge opening 21. A valve seat 28 is retained in the valve passage against a shoulder 29 dividing the passage into an upper chamber 30 and a lower chamber 30'. A longitudinal passage 3| is formed in the valve seat between the two chambers in which a valve stem '32 is received; An enlarged head 33 at the lower end of the valve stem is provided with a tapered face adapted to engage the annular lip formed around the lower opening of the passage 3|. A coil spring 34 is carried on the upper portion of the valve stem projecting through the valve seat into the upper chamber 30 which is also provided with threads 35 that receive a spring retaining nut 36. The coil spring is compressed between is shown, for the sake of convenience,

moving the hose ll.

threading the valve stem into the retaining nut and thus adjusting the compressive seating force of the valve spring. The slot 3'! is made accessible through the valve outlet 21 by simply re- During the adjusting of the retaining nut on the valve stem, frictional resistance normally prevents the nut from turning with the valve stem so that the adjustment may be made without removing the valve 16 from the regulator outlet. To insure that the nut will not turn, a slight protrusion (not shown) may be provided on the wall of the chamber to act as a stop against rotation, but which will not impede longitudinal movement of the nut along the valve stem.,

The valve seat 28 is preferably made of nylon, which is a material having the desired resilience to afford a gas-tight valve seating surface, and sufiicient strength for the purposes of the invention. The seat is in the form of a cylindrical bushing in which a portion of reduced outer diameter 38 forms an annular space 39 between the bushing and the bore of the lower chamber 39 which opens directly into the valve discharge outlet. A small opening 40 constituting a metering orifice, extends substantially radially between the annular space 39 and the gas passage 3! at the upstream side of the closed end of passage 3!. Thus the orifice 40 is an open route for gas delivered to the inlet end of the valve in chamber 30, around the closed terminal opening of passage 3| to the lower chamber 30 and discharge outlet Zl.

The portion 23 of the valve body on which the delivery hose I? is received, is provided with opening 41. The valve seat is positioned when it is pressed into the valve body for securement therein, so that the metering orifice 40 registers with the opening M as shown in the drawing. Thus the orifice is accessible for removal of dirt or other flow-obstructing material that may lodge therein, without dismantling the valve. A simple tool, such as a small drill, may be used by removing the hose conduit I! allowing the tool to be inserted into the orifice through the opening 4|.

In the operation of the apparatus described, the control handle l8 of the regulator is adjusted for delivery of the desired pressure to the metering valve. The gas flow through the apparatus and therefore the fiow delivered to the oxygen tent is the rate at which the gas is metered through the valve Hi. This flow is determined by the regulator pressure supplied to the inlet side of the valve by the regulator and the prevailing pressure at the downstream side of the valve, i. e., the pressure drop across the metering orifice. Since the tent hood for most purposes is at, or near, atmospheric pressure so that the downstream side of the valve is always substantially at atmospheric pressure, the gas flow is determined wholly by the pressure of the gas administered to the inlet of the metering valve. Thus the adjustment of the regulator handle 18 forv administering the gas at desired pressures to the metering valve controls the rate of flow of the gas. The flow gage i9 is calibrated with respect to such pressures to indicate the rate of flow.

During the operation of the apparatus in the normal gas flow range the head portion 33 on the valve stem is retained by the valve spring against the valve seat so as to close the terminal opening of the passage 3|. The gas then passes entirely through the metering orifice which, because of its small flow area, enables a sensitive control of the gas flow rate by adjustment'of the regulator control handle. When the control handle is turned to the position corresponding substantially to the maximum rate of fiow in the range of normal usage the gas pressure acting.

controlhandle has been adjusted so that'the flowis'increased slightly above 13'liters/min., the pressure acting on the valve member will be sufficient to unseat the valve head portion of the valve stem from the valve seat, whereupon a much greater flow of about 150 liters/min. is automatically administered to the oxygen tent Without further manipulation of the control on the valve stem is sufficientto overcome the seating force of the valve spring 34 causing the valve stem head portion to be unseated from the valve seat around the opening of the'passage 3|. Thus, in addition to the metering orifice, the

cross-sectional area of the larger passage 3| is described.

To illustrate the improved utility of the gas metering apparatus, suppose there is to be a patient committed to the oxygen tent l I for therapeutic treatment. The regulator adjusting handle is manipuated to deliver gas through the metering valve to the oxygen tent. The nominal range of normal use for the apparatus shown and described is from five to thirteen liters/min. The regulator delivery pressure corresponding to the flow of five liters/min. is approximately 7.75 p. s. i. and the pressure corresponding to the how of 13 liters/minis 37 p. s. 1. Thus the regulator a-djusting handle is adjusted to deliver the gas to the valve 16 at pressures corresponding to the desired rates of flow within this normal range. The flushing flow is from 150 liters/min. to 200 liters/- min. and this flow commences when the regulator delivery pressure is set for approximately 42 p. s. 1. Thus the flush flow is set to commence at a slightly higher flow than 13 liters/min. and

'- the low flow range is therefore extended a small amount above the rate of 13 liters/min. This is done to establish a slight pressure differential between the regulator pressure corresponding to the flow of 13 liters/min. and the pressure corresponding to the flushing flow of 150 liters/min. The necessity for increasing the regulator delivery pressure by this amount prevents the possibility of delivering a flushing rate of flow when the regulator is intended to be set for a rate of 13 liters/min. The low flow range is represented on the scale IQ" of the flow indicating gage l9 by the portion of the scale having spaced'markings corresponding to the adjusted flows, and the range of flushing rates of flow is represented by the heavy line labelled Flush. The last marking of the calibrated scale for the low fiow range corresponds to 13 liters/min. which it will be seen is separated by a small intervening space from the flush zone. At first the operator will turn the regulator handle to increase the flow up to the top of the low fiow range. When the regulator handle. The interior of the oxygen tent is purged at the flushing fiow until the oxygen concentration is sufiicient for use. trol handle is turned in the direction to decrease the flow, the pressure on the valve stem head portion is reseated on the valve seat automatically reinstating the metering valve for delivering precisely controllable oxygen flows in the normal range according to the requirements of the patient. apparatus may be quickly and easily operated to increase the rate of delivery above the normal range of operation and also, in the reverse, may be readily operated to reduce the flow from a high rate to the normal low flow range. Moreover,

the improved apparatus is capable of controlling the flow of oxygen in a precise manner.

The invention, of course, is not limited to the specific embodiments herein illustrated and rle scribed, but may be used in other ways without departure from its spirit as defined by the following claims.

We claim:

1. Apparatus for metering oxygen to an oxygen,

tent comprising, anoxygen tent enclosure, a source of oxygen, a pressure regulator connected to said source for delivering oxygen at a regu-' lated metering pressure to a metering valve connected to the delivery side of said regulator, said valve having a small opening and a large opening in parallel-flow relation, means associated with said regulator for adjusting said metering pressure, means responsive to changes in said adjusted metering pressure for automatically causing oxygen to be delivered solely through said small opening or through both of said openings of said metering valve in accordance with the value of said metering pressure, and means for conducting the oxygen passing .through said metering valve opening or openings to said oxygen' tent enclosure.

; 2. Apparatus. for metering oxygen to an oxygen tent comprising an oxygen tent enclosure, a source of gas, a pressure regulator connected to said source for delivering oxygen at a regulated metering pressure to a metering valve connected to the delivery side of said regulator, a pressure control handle for adjusting said metering gas pressure, first and second valve openings in said metering valve disposed in parallel gas flow relationship, said first opening being of relatively small cross-sectional area and said second opening being of relatively large cross-sectional area, pressure responsive means associated with said second opening normally seated thereagainst to close said opening, said pressure adjusting handle being adapted to control the fiow through said first opening by the adjustment of said metering gas pressure, said pressure-responsive means being adapted to be unseated from said second opening by gas pressure corresponding to a predetermined rate of flow of the gas through the first opening, and gas conduit means for delivering the oxygen from said metering valve to said enclosure whereby the gas flow to said enclosure may be precisely adjusted at any selected flow rate through said first opening within a normal When the con- It will thus be seen that the gas metering v 7 range of flows by adjustment of said regulator control handle and is automatically delivered to said enclosure at a much greater rate when the regulator control handle is adjusted to a position'corresponding substantially to the maximum flow in said range.

3. A valve for metering gases comprising an elongated valve body having an inlet and an outlet at the opposite ends thereof, a threaded portion at the inlet end enabling said valve body to be secured in a gas administering instrument, a cylindrical portion at the outlet end for accommodating a gas conduit which is adapted to be frictionally retained in a gas-tight manner thereon, a valve seat in the valve body, first and second chambers on opposite sides thereof communicating respectively with the valve inlet and outlet, said valve seat being'longi'tudinally elongated and having a relatively large diameter passage extending therethrough between said first and second chambers, a valve member smaller than said passage extending substantially centrally through said passage, an enlarged head portion at one end of said valve member adapted to be seated against the terminal end of said passage in said second chamber, the other end of said valve member extending into said first chamher, an adjustable retaining nut thereon, a spring compressed against said retaining nut urging said head portion into engagement with said valve seat, means for adjusting the compression of said valve spring, an annular space between said valve body and a cylindrical portion of said valve seat, said space communicating with said second chamber, a cross passage inthe valve seat of relatively small cross-sectional area extending substantially radially of the axis of said valve and the valve seat between said relatively large passage and said annular space, said cross passage enabling gas to be metered therethrough at rates dependent upon the pressure differential between the valve inlet and outlet, said head portion being adapted to be unseated from said valve seat at a predetermined pressure differential, and an opem'ng in said cylindrical portion of the valve body in register with said passage of relatively small cross-sectional area adapted to enable the insertion of a cleaning tool therethrough into said cross passage, said opening being effectively sealed by the gas conduit received thereon.

4. A valve for metering gases comprising an elongated valve body having an inlet and an outlet at opposite ends thereof, a valve bore extending between said valve inlet and outlet, a shoulder in said bore, a cylindrical bushing positioned against said shoulder forming a valve seat, a portion of reduced diameter at the outer end of said cylindrical valve seat bushing forming a space the-rearound in said valve bore, a longitudinal valve passage through said valve seat bushing, a lateral metering passage in said bushing connecting said valve passage and said space, an elongated valve element extending through said valve passage, one end of said valve element having an enlarged head portion engageable with said valve seat to form a valve closure for said longitudinal valve passage, said opposite end having a threaded retaining nut longitudinally adjustable thereon, a valve spring compressed between said retaining nut and said valve seat bushing urging said valve element into closed position against said valve seat, and means for adjusting said retaining nut and regulating the compression of said spring, said valve element being adapted normally to close said longitudinal passage and to be unseated from said valve seat at a predetermined rate of flow through said lateral metering passage.

JOHN GILROY.

ARTHUR R. WIESE, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,093,576 McNutt Apr. 14, 1914 1,774,690 Willoughby Sept. 2, 1930 1,858,400 Koehler May 17, 1932 2,185,103 Heigis Dec. 26, 1939 2,286,713 Burks June 16, .1942