US2217575A - Respiratory appliance - Google Patents

Description

C. VON HOFF @szi. 1%, 1948.

AIPLI'ANCE Original Filed Nov. 15, 1935 Patented Oct. 8, 1940 V UNITED STATES PATENT OFFICE nnsrmn'roav APPLIANCE Carl von Hofi, Essen, Germany, assignor to Otto Heinrich Drager, Lubeck, Germany ber 14, 1934 9 Claims.

This is a division of my co-pending application No. 49,981, filed November 15, 1935.

This invention relates to respiratory appliances having circulation of the respiratory air and automatic lung-controlled oxygen feeding.

In respiratory appliances of this kind, arrangements are known for avoiding excess of nitrogen. The arrangements aim at the passa e or" a suiflcient quantity of nutritive gas or oxygen whilst 10 avoiding the constantly uniform nutritive gas feeding which considerably shortens the duration of use of the appliance, and which is mostly provided in addition to the automatic lung-controlled feed.

In order in a respiratory appliance having automatic lung-feeding, to adapt the supply of oxygen exactly to the demand at any time, the respiratory appliance is, in accordance with the invention, connected to an intermediate container of variable volume and maintained continuously under regulated pressure of the oxygen so that every movement of the wall of the respiratory bellows is mechanically transmitted andwhich container is also connected with the respiration bellows by means of a connecting member adapted to introduce the oxygen into the bellows and having a force closure control. so that on each increase of volume, oxygen passes from the storage container into the intermediate container andon each diminution of volume, oxygen is pressed out oi the container into the respiration bellows. In order not to render more difllcult the movement of the wall of the respiration bellows by means of the pressure of .the

oxygen inside of the intermediate container, pressure compensating means may be provided; for example, a movable bottom or piston which subdivides the container, is actuated by lever transmission and has a double contacting action, a

spring member operating in opposition to the oxygen pressure, or the like;

The respiration bellows is in general larger than the intermediate container connected to it. The ratio of the dimensions taken in connection with the position oi. the parts with regard to one another is so chosen that the quantity of respiration air in the bellows has a certain amount of oxygen, for example, about 440% added to it. The intermediate container is during the employment of the appliance, incontinuous direct connection with the reducing valve of the oxygen container, which may be, for example, adjusted to a pressure of 100 mm. water column. If, during the inspiration, the volume of the respiration bellows decreases, then with the corresponding diminution of the intermediate container, the oxygen located therein must pass over through the connection provided into the respiraamounts to mm. water column, then a coun- 15 I ter pressure on the valve in the connecting conduit of about mm. will suflice for closing it.

For the respiration bellows in appliances according to the present invention, bellows of concertina-like type having a fixed lower wall and a movable but rigid upper wall, are particularly suitable. Bellows of this kind have a volume and a variation of volume which can be easily determined-which fact is important in connection with the present appliance for the reason 25 that the oxygen supply is dependent on the variation of volume of the respiration bellows. Furthermore these bellows render possible easy transmission of the movement of their walls. If the transmission of the movement is efiected by 30 means of a one or two-armed lever, then the power necessary for the alteration of volume can be diminished by the alteration of the point of connection of the intermediate container with the short lever arm. This power is also in any 35 case less on account of the smaller volume of the intermediate container as compared with the respiration bellows. The oxygen pressure existing in the intermediate container facilitates the expansion of the respiration bellows and thereby 4o diminishes the resistance of the wall of the bellows during the expiration. II, as is provided for, the oxygen pressure in the intermediate container is eliminated by means of a compensating arrangement, then the alteration of volume of the inter- 45 mediate container does not cause any overload during the movement of the walls of the respiration bellows. The force for opening the valve in the connecting conduit can be completely eliminated by the transmission ratio of the long lever 50 arm to the short one. I

The advantage oi. the intermediate container as a. measuring device resides, as compared with the known arrangements, in the fact that the conducting path for the respiration air remains as whole pressure of the oxygen containe but, by

the direct connection of the reducing valve with the intermediate containenthe supply of oxygen is in the first place limited to the capacity of the latter and the quantity of oxygen passing out of the intermediate container into the conducting path is limited'tothe particular amount which is determined by the alteration of volume of the respiration bellows.

In order that the invention may be fully understood, some embodiments thereof will now be described by way of example by reference to the accompanying drawing in which the figures of the drawing are restricted to that part of a respiration appliance which is necessary for the comprehension of the invention. The drawing shows in:

Fig. l, the mechanical and pneumatic connection of the respiration bellows with an intermediate container subdivided by means of a movable bottom, and the always open connection of the latter with the reducing valve of the oxygen container,

Figs. 2-4, the same connection with a singlespace intermediate container with various means for the transmission of the movement,

Fig. 5, a tension spring in the interior of the intermediate container, and

Fig. 6, a compression spring above the intermediate container acting as a compensation for the oxygen pressure.

According to Fig. 1, the intermediate container b is provided with a pressure compensating means consisting of a movable intermediate bottom d,

which is connected with the two stationary boundary walls after the manner of a concertina. Into each of the two boundary walls, a branch or the conduit 0 to the reducing-valve c opens, so that both halves of the container b are under the same oxygen pressure. By means of thetwo-armedlever 9 adapted to swing on thestationary fulcrum f,the movement of the wall of the respiration bellows a is transmitted to the movable intermediate bottom d of the containerab. During this movement,

the intermediate bottom (1 presses the oxygen alternately out of the lower and upper container half I) through the conduits c which are likewise connected to the two boundary walls of the container, the oxygen passing either directly or indirectly into the respiration bellows a. As a consequence of the fact that the bottom d is operated upon by the oxygen on both sides, the pressure in the intermediate container above and below the bottom 11 is compensated. For the movement of the bottom d, only the power required for opening the valve :0 in the connecting conduit 0 is consequently necessary. If, for example, the oxygen pressure in the intermediate container amounts to mmQand the load of the valve 1: to about 20 mm. more, then there is opposed to the transmission of movement of the respiration bellows to the intermediate container only the small pressure of 20 mm., which, however, is almost entirely eliminated by the arrangement of the intermediate bottom d on the short lever arm. The magnitude of the movement of the intermediate bottom (1 and consequently the alteration of volume of the container 1), can be adjusted by providing on the short arm of the lever g a number of bores,

wherein a variable positioning of the bottom-811s rendered possible. in this embodiment in consequence of the subdivision of the intermediate container'i), the oxygen therefrom is pressed into the respiration bellows, not only when the latter contracts, but also when it expands.

In the embodiment shown in Fig. 2, the transmission of motion from the respiration bellows a to the intermediate container b is effected by means of the one-armed lever g fulcrumed at I, the point of application of the respiration bellows a being on the long lever arm, and the point of application of the intermediate container b being on the short arm. In this case, the conduit 0 leads from-the intermediate container 1) to the reducing valve 0, and the conduit c with the valve :0 leads to the respiration bellows a.

In Figure 3, the intermediate container b is arranged in the middle of the respiration bellows a. Both of these are retained in position so as to be movable by means of the common top wall. From the reducing valve 0 the conduit 0 leads into the intermediate container b which is connected with the respiration bellows a by means of the connection 0 which is controlled by force closure.

In the embodiment shown in Figure 4, the respiration bellows a is located after the manner of a wedge between two walls connected by a hinge f, the upwardly directed wall g being adaptedto swing and, owing to this capacity or swinging, produced by the alteration of volume of the respiration bellows a. effecting the alteration of volume of the intermediate container b. The container b, which is adapted to be arranged at any desired place between the two walls, is, in this case, illustrated as being located on the long lever arm. The intermediate container b is also connected by means of the conduit 0 with the reducing valve 0 and by means of the conduit which is controlled by force closure with the respiration bellows a.

Forcompensating for the oxygen pressure, there is provided, according to Figure 5, a tension spring arranged inside the intermediate container b, which spring, acting against the oxygen pressure, tends constantly to draw the movable top wall of the container downwards, whilst in the construction shown in Fig. 6, there is arranged above this movable top Wall's. compression spring supported at its other end. It the power demand for compressing the intermediate container b exceeds the permissible load on the lungs, which for example, may be the case in the em bodiments illustrated in Figs. 3 and 4, a compensating means of this kind for the pressure is desirable. In an arrangement such as is shown in Figure 2, wherein the operating power for the intermediate container is applied to the short lever arm, a pressure compensating means is not necessary.

With the ipfle rmediate container b the variabilityof its volume is illustrated on the drawing by means of an intermediate bottom moved after the manner of a concertina, or by a similarly moved top wall. The same object can be obtained by means of a bellows of another kind, or a stationary hollow cylinder having a piston moved within it by the action of the respiration bellows.

The position of the respiration bellows with the quantity meter regulating the oxygen supply is the same as is general with circulation appliances for the respiration bellows, for example, between pipe.

I claim;

1. In a lung controlled respiratory appliance having automatic oxygen supply, the combination of: a respiratory bellows, a source of oxygen supply, and an intermediate variable volume container in communication with said om-- gen supply source and said respiratory bellows in such manner as to allow of passage of oxygen from said source to said container and from said container to said bellows, and said container being constantly positively operatively connected to the wall of said bellows such that every variation in volume of said bellows.pro duce's a proportional variation in volume of said intermediate container, every volume increase of said container causing oxygen to pass from said source of supply to said intermediate container and every volume diminution thereof causing oxygen to be forced from said container into said bellows in an amount which is a constant uniform percentage of the air respirated.

2. In a 'lung controlled respiratory appliance having automatic oxygen supply, the combination of: a respiratory bellows, a source oi oxygen supply; an intermediate variable volume container in communication with said oxygen supply source and said respiratory bellows in such manneras to allow of passage of oxygen from said source to said container and from said container to said bellows; anda lever connected at one end to said container.and constantly responsively connected at the other end to said bellows for positively operatively connecting said container to the wall of said bellows such that every variation in volume of said bellows produces a proportional variation in volume of said container, every volume increase of said container causing oxygen to pass from said source of supply to said intermediate container and every volume diminution thereof causing oxygen to be forced from said container into said bellows in an amount which is a constant uniform percentage of the air respirated.

3. In a lung controlled respiratory appliance having automatic oxygen supply, the combination of a respiratorybellows, a source of oxygen supply, an intermediate variable volume container communicating with said oxygen supply source and said respiratory bellows in such manner .as to allow of passage of oxygen from said source to said container and from said container to said bellows and said container being constantly positively operatively connected to the wall of said bellows such that every variation in volume .of said bellows produces a pro- .portional variation in volume of said interme diate container,- every volume increase of said container causing oxygen to pass from said source of supply to said intermediatecontainer. and every volume diminution thereof causing oxygen to be forced from said container into said bellows in an amount which is a constant uniform percentage of the air respirated, and force closure means for preventing passage of oxygen from said container to said bellows except during movement of the latter,

4. In a lung controlled respiratory appliance having jautomatic oxygen supply, the combination off [a respiratory bellows, a source of oxygen supply, an intermediate variable volume container, conduits connecting said container respectively to said oxygen supply source andto said respiratory bellows in such manner as to allow of passage of oxygen from said source to said container and irom said container to said bellows, and said container being constantly positively operatively connected to the wall 01 said bellows such that every variation in volume of said bellows causes a proportional volume variation of said intermediate container,"every volume increase of said container causing oxygen to pass from said source of supply to said intermediate container and every volume diminution thereof causing oxygen to be forced from said container into said bellows in an amount which is a constant uniform percentage of the air respirated,

r and a. valve disposed in the conduit connecting" said container to said bellows, said valve being held normally closed under the action of a force, 15 such as a spring, greater than the pressure of the oxygen in said container.

5. In a lung controlled respiratory appliancehaving automatic oxygen supply, the combination of: a respiratory bellows; a source of oxygen supply; an intermediate variable volume container communicating with said oxygen supply source and said respiratory bellows in such manner as to allow of passage of oxygen from said source to said container and from said container to said bellows; and a lever connected at one end to said container and at the other end to said bellows positively operatively connecting said container the wall of said bellows such that every variati n, in volume of said bellows causes a volume vvariation of said container, every volume increase of said container causing oxygen to pass from said source of supply to said intermediate container and every volume diminution thereof causing oxygen to be forced from said container into said bellows in an amount which is a constant uniform percentage of the air respirated, and the point of engagement of said lever with said container being variable for the purpose of controlling the variation of volume of said container.

6. In a lung controlled respiratory appliance having automatic oxygen supply, the combination of a respiratory bellows; a source of oxygen supply; an intermediate container of variable volume communicating with the'respiratory bellows'and the oxygen supply source; and a movable bottom subdividing said container, said bottom being operatively connected to the wall of said bellows such that every wall movement of said bellows is transmitted to said ,bottom whereby'each expansion and contraction of said bellows causes alternately the evacuation of one side and the simul-' taneous filling of the other side of said container.

'7. In a lung controlled respiratory appliance having automatic oxygen supply, the combination of: a respiratory bellows; a source of oxygen supply; an intermediate variable volume container 5 communicating with said oxygen supply source and said respiratory bellows in such manner as to allow of passage of oxygen from said source to said container and from said container to said bellows; and said container being positively operatively connected to the wall of said bellows; and a tension spring disposed within said container, said spring-normally tending to contract said container, the arrangement being such that every wall movement of said bellows causes a volume variation of said container whereby on every volhaving automatic oxygen supply, the combination or: a respiratory bellows; a source of oxygen supply; an intermediate variable volume container communicating with said oxygen supply source and said respiratory bellows in such manner as to allow of passage of oxygen from said source to said container and from said container to said bellows; and said container being constantly positively operatively connected to the wall of said bellows; and a compression spring arranged above and connected to the top of said container. the arrangement being such that every variation in volume of said bellows causes a volumevariation of said container every volume increase of said container causing oxygen to pass from said source of supply to said intermediate container and every volume diminution thereof causing oxygen to be a forced from said container into said bellows in an amount which is a constant uniform percentage of the air respirated and the pressure of the oxylever operatively connected to said bellows and tosaid container for the purpose of transmitting the movement of said bellows to said intermediate container, whereby each expansion and contraction of said bellows causes alternately the evacuation of one side and the simultaneous filling of the other side of said container.

CARL VON HOFF.

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