Pressure compensating device for multiple gas chambers
United States Patent 2107596

The present invention relates to improvements in pressure compensating devices for multiple gas chambers and is a division of application Serial No. 17.365, filed April 19, 1935, and in one Sinstance the invention relates more particularly to a device for equalizing pressure between the air...

Marcel, Bourdon Pierre
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B60C23/00; B60C29/00
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The present invention relates to improvements in pressure compensating devices for multiple gas chambers and is a division of application Serial No. 17.365, filed April 19, 1935, and in one Sinstance the invention relates more particularly to a device for equalizing pressure between the air chambers of twin automobile tires.

Another object of the invention is to produce an improved compensating device which may Smaintain a constant pressure difference between two gas or air chambers where it is desirable that the pressure be not equalized but be maintained at predetermined pressure differences.

The invention has for a further object the production of a compensating device for the purpose indicated which is made up of simple parts grouped in a simple organization. The device forms a unit which may be used either alone or in any appropriate numbers or combinations.

With the foregoing and other objects in view, the invention will be described more particularly in the following specification and more particularly pointed out in the appended claims.

In the drawings, in which like parts are denoted by the same reference characters throughout the several views, Figure 1 is a diagrammatic view of a unitary compensating device constructed in accordance with the present invention.

Figure 2 is a section taken on the line 2-2 in Figure 1.

Figure 3 is a view similar to Figure 2 with the membrane sleeve inflated.

Figure 4 is a diagrammatic view showing a modified form of the device.

Figure 5 is a cross section taken through a commercial device showing the unitary construetion of Figure 1.

Figure 6 is a similar view showing a commercial application 'of the modified device according to Figure 4.

Figure 7 is a cross section showing a combination unit.

Figure 8 is a diagrammatic view showing a grouping of a plurality of the units, and Figure 9 is a sectional view showing a commerfial adaptation of the grouping of the Plurality ::f the units.

Referrinq more particularly to the drawings, ind for the present to Figures 1, 2 and 3, wheren there is shown a simple form of unit desigiated generally at A, I designates a tube having hambers 2 and 3 separated by a partition 4. The hamber 2 may connect with the interior air t pace of one automobile tire or with any other t gas container, while the tube end 3 may connect with the air space of a twin or other automobile tire or other gas container. The chambers 2 and 3 are provided with one or more ports 5 and 6 disposed on opposite sides of the partition 4 and these ports are arranged to communicate with the interior space housed about by a flexible or elastic membrane sleeve 10 bound securely, as indicated at 7 and 8, to the metal or other tube I at opposite sides of the ports 5 and 6.

The device may be contained within a collar or casing 9 allowing ample room for the membrane 10 to expand outwardly from the outer wall of the tube I. The membrane 10, by reason of its own inherent elasticity, will seek a position stretched rather tightly over the outer cylindrical circumference of the tube I so as to close both ports and 6 and in this respect it functions as a valve for both of the ports, acting independently and locally upon each port.

When there is no pressure in the chambers 2 and 3, the membrane sleeve 10 is applied closely or tightly about the tube I thus closing the ports 5 and 6. This is illustrated in Figure 2 by "position I." Whenever the chamber 2 contains pressure in excess of the contractile strength of the membrane sleeve 10 it will act through the port 5 upon such membrane thus inflating the membrane by first causing it to bulge locally away from the tube 1. As soon as the membrane is lifted off the port, as shown in position II in Figure 2, the effective area of the membrane increases and it is inflated to the position III of Figure 3, wherein the ports 5 and 6 are in communication. In this position communication between the chambers 2 and 3 is established and gas flows freely from chamber 2 into chamber 3 until pressures in the two chambers become equal. After the pressures have been thus equalized if the pres- 4, sure in one chamber, at any time, for any reason becomes greater than that in the companion chamber, the gas flows from that chamber to the other chamber through the equalizing device until stability of pressures is restored. This will go 4; on automatically maintaining a condition of equality of pressures of the two chambers 2 and 3. On the other hand, should the pressure fall below the predetermined maximum in any chamber, then the pressure from the companion cham- -„ ber will flow over to distribute the loss and maintain pressure equality. This is true within limts. Of course should a blow-out occur in one of he tires thus completely evacuating, for instance, the chamber 3, then if the compensating valve 5 device remained open, the companion tire or chamber 2 would also be evacuated completely through the rupture of the blown-out tire and the vehicle would lose the complete support of , both of the twin tires. this the elastic mem In emergencies such as this the elastic membrane sleeve 10 will collapse against the outer wall of the tube I after the pressure in the chamber 2 has fallen below the limit required to expand this membrane against its inherent elasticity. Such limit will be chosen to be one such as will retain sufficient pressure in the remaining tire to properly support the vehicle without endangering the tire itself, thus enabling I the vehicle to .be run on this remaining tire for a considerable distance if need be before reaching a garage or service station where repair or replacement may be made to the blown-out companion tire. In closing, the membrane sleeve 10 will first collapse against the port I of the chamber 3 in which the heavy fall in pressure has occurred by reason of the blowout. In other words the device will pass through the position shown in Figure 2 before it returns to the "position I," The distention of the membrane sleeve 10 in response to the pressure within either chamber will depend upon the tension inherent in the rubber sleeve 10 and also upon the port area or diameter of the ports I and 1. From the moment the membrane sleeve 10 closes to the position shown in Figure 2, communication is prevented between the two chambers 2 and I and the deflating chamber can continue to de. flate without affecting the pressure condition o1 36 its companion chamber, In practice the following effects will be securec from the use of the improved compensatinil device.

1. When inflating, the two chambers or tire will be caused to receive equal pressures.

2. The two chambers will remain at eque pressures provided such pressures exceed a pre determined minimum which minimum depene upon the tension of the rubber sleeve I0 an the cross sections or port areas of the ports and 6.

3. If the pressure in one of the chambers fa] below this predetermined pressure minimum tl pressure in the companion chamber ceases 0 drThe collar or device I is located a desired dl tance from the tube I so as to allow for the fr expansion and contraction of the membra sleeve I0 but such collar 9 acts as a stop 5 arrest any undue inflation of the membrane It also reinforces and supports the membra I0 in case of excessive inflation to avoid inJr or bursting of the membrane sleeve. The in rior space between the collar 9 and the me brane sleeve 10 may be open at the ends of collar to the atmosphere so that there is no ci fined air space interfering with the free me ment of the membrane sleeve 10.

Referring more particularly to Figure 4 which a modified form of device indicated ger ally at B is provided, a similar arrangemenl tube I, chambers 2 and 3, partition 4, porl and 6 and membrane sleeve 10 is provided; in this case instead of providing a-collar, enclosed casing 90 is fitted tightly to the tuW at the opposite ends of the membrane sleev and this casing 90 houses a confined volum air about the membrane sleeve 10.

The end walls 90 of the casing 9' are prov - with out-turned flanges or bearing portior which are fitted in an air-tight manner about the pipe or tube I. The confined space within the casing 0s is placed in communication with one of the chambers, for instance the chamber 3, by an orifice or port 12. By reason of this arrangement it will be seen that the chamber $ will always be at a lower pressure than chamber 2. Assume that pressure is being introduced into chamber 2; then acting through the port 5 and against the rubber membrane sleeve 10 it will expand such sleeve away from the tube I in the manner already described in connection with Figures 1, 2, and 3, and shown in Figure 4 so that ultimately the port S will be opened and communication thus established between chambers 2 and 3 with a consequent interchange of pressure between these two chambers. During this interchange of pressure the fluid which is admitted to chamber 3 will pass through the orifice 12 and into the confined space of the enclosed casing $9 about the exterior surface of the rubber membrane sleeve I0. Thus the sleeve 10 will be subject to the pressure of chamber 2 from within and of the pressure of chamber 3 from without. The sleeve 10, as previously explained, is of rubber stretched over the tube I so that it inherently seeks a position fitting tightly against the tube I and its ports 6 and 6.

This elastic tension or contractile stress within the rubber sleeve 10 is augmented or supple- 3o Smented by the external pressure in the enclosed I casing 9h acting on the outside of the sleeve.

.Thus the pressure within the chamber 2 must Sovercome this combined inherent stress and ex-" Sternal pressure and as long as it can do so the i ports I and 6 will remain open and there will I be a flow of gas from the chamber 2 to the chamber 3. It will be seen however that the a membrane sleeve 10 will contract and close the ports 5 and 6 before any equality of pressure is a established in chamber 3 and therefore chamber - 3, in the arrangement shown in Figure 4, can is never reach the same pressure as in chamber 2.

Ad The pressure differential would depend upon the p elastic strength or stress of the membrane sleeve 10 and this may be selected so as to give the l.s desired result. Considered in another way the ie pressure in chamber 3 will always be less than to that in chamber 2 by the amount necessary to open the membrane sleeve 10. When pressure r0 3- is cut off from being introduced into the chaintee ber 2, counter-pressure within the enclosed casne ing 9' will promptly cause the membrane sleeve to 10 to close against the ports.

10. If at any time after inflation there should 5i .ne occur a pressure drop in chamber 3, or a rise iry in chamber 2, so as to disturb the pressure difte- ference, the membrane 10 will again open to m- permit flow from 2 to 3 to compensate for the the variation. 0 on- This flow will continue until the inherent tenye- sion of the rubber in the sleeve 10 will cause this sleeve to close against the port 6. Further in flow of the fluid will then of course be prevented.

ier- If pressure falls in the chamber 2 or rises in 4 tof the chamber 3, obviously the membrane sleeve ts S10 will remain closed against the ports 5 and 6 but and no movement of the gas from the chamber an 3 to chamber 2 will be permitted.

be I In short, the device B shown in Figure 4 will e 10 have as its effect to maintain between chambers e of 2 and 3 a normal difference of pressure which will depend, all other things being equal, on the initial 'ided or inherent tension of the sleeve 10. If the presLs Ob , sure becomes lower in the low pressure chamber the pressure in the high pressure chamber will drop by reason of the opening of the valve and the flow of gas from chamber 2 to chamber 3; and this action will continue until sufficient presSsure in chamber 3 is established to permit closing of the valve 10, at which time there will be a substantial re-establishment of the pressure differential between the two chambers 2 and 3. Thus the pressure differential will be for all purposes a conSo stant. Whenever there is a rise in pressure in the low pressure chamber 3, or a drop in pressure in the high pressure chamber 2, then the device acts as a check valve preventing flow from chamber 3 back to chamber 2.

Referring more particularly to Figure 5, 2a and 3S represent two tubes communicating at their outer ends separately with two chambers or tires or the like. At their inner ends the tubes connect with ducts or channels 14a and 14b which U are separated by the partition 4a. The channel 14a communicates at 19 with a passage 18 in the valve stem or inflating nozzle 20. The channels 14a and 14b are made in a body 30 of metal or other suitable construction in which is also con5 structed the partition 4a. The channels 14a and 14b on opposite sides of the partition 4a respectively lead beneath a rubber membrane sleeve 10I which normally shrinks or contracts against the ports 5a and 6a in the outer ends of the channels.

The sleeve 10a may be held in place by a ring 15 and a nut 16 and the valve stem 20 may be also held in place by an apropriate washer and nut 31 screwed on to the same and bearing against an enclosing cap 17. However the enclosing cap 17 will merely form a protection for the rubber sleeve 10a but will not exclude atmospheric air from the outside of said sleeve. Thus the device is a commercial adaptation of the form A shown in Figures 1, 2, and 3. A pump or inflating hose is connected with the valve stem 20 and air or other fluid is pumped through the passages 18 and 14a into the tube and its chamber 2a.

When the pressure rises to such an extent as to exceed the initial or inherent strength or tension of the membrane sleeve 10a, this sleeve will be expanded away from the ports 5a and 6a and the pressure will flow from one channel 14a into the other channel 14b and thus into the tube 3a and its chamber. Therefore according to this device there will be an equalization of pressures maintained at all times between the two chambers, at least as long as the pressure is high enough to keep the membrane sleeve 10a open. In other words the equality of pressure is maintained so long as conditions are normal. If an excessive I deflation occurs in one of the chambers, the de- 3 flation in the other chamber is limited by the r initial or inherent tension of the sleeve 10a which c may be chosen as strong as one wishes. The I elastic strength or tension of the rubber out of which the sleeve 10o is made may be very strong a or comparatively weak. Where it is of great s strength, high pressures will be required to raise a the same from the ports 5a and 6a. Therefore where a high strength rubber sleeve 10a is em- p ployed and a severe drop in pressure is caused in n ane of the chambers, the other chamber will only p give up a small portion of its pressure to that of 4 ;he deficient chamber owing to the fact that after 6 i comparatively small drop in pressure from the m uigh pressure chamber, the strong membrane b ;leeve 10a will close thus preventing the loss of te my further pressure in such high pressure cham- tt )er. ti On the contrary if it is desired that equality of m pressure in the chambers be maintained without regard to a rapid and low drop in the pressure in one of the chambers then the material of which the membrane sleeve 10a is made may be so selected as to be of very small strength or tension in which case it will require very little pressure to lift it off its seat and away from the ports 5A and 6a and thus an interchange of pressure will go on for a long time and to a comparatively low degree.

Referring more particularly to Figure 6, this figure shows a commercial adaptation of the device B which is illustrated diagrammatically in Figure 4. In this Figure 6 the low pressure chamber is indicated at 3b while the high pressure 1 chamber, or the tube connecting the high pressure chamber with the device, is designated at 2b.

These tubes connect with the casing 30b and with chambers to opposite sides of the partition 4b.

The hollow valve stem is represented at 20b and 21 serves to introduce air into the chamber 2b. The ports 5b and 6b are controlled in the manner already described by a rubber or elastic sleeve 10 which is contained within a casing 17b surrounding the membrane I b and having a tight fit at 23 21 with the casing 30b. The casing has an orifice or port 12b establishing communication between the low pressure chamber 3b and the chamber confined by the casing 17b.

This casing 17b makes an air-tight fit with the casing at 23 and also at 31b.

A device according to this construction has the following advantages: (a) The two chambers 2b and 3b are inflated to unequal pressures depending on the tension of the membrane I 0b.

(b) If th3 pressure drops in the low pressure chamber 3b it drops also in the high pressure chamber 2b until the pressure in the high pressure chamber 2b falls so low as not to be able to lift 4(0 the valve sleeve I Ob against its tendency to collapse against the ports 5b and 6b.

(c) If the pressure rises in the high pressure chamber 2b it rises also in the low pressure chamber 3b. (d) If the pressure drops in the high pressure chamber 2b or rises in the low pressure chamber 3b there will be no effect on the other chamber.

Referring more particularly to Figure 7, in this figure there are two of the devices B coupled together. The valve stem or hollow nozzle is indicated at 20c and serves to introduce gas under pressure into the two chambers 2c and 2d.

The chamber 2c of one of the units B is divided by a partition 4c from the low pressure chamber c, which low pressure chamber communicates by neans of a port or annular channel 12c with the onflned space on the exterior of the elastic memwrane sleeve I0c.

An air-tight casing 17c serves to confine the gas bout the membrane sleeve and this membrane leeve is adapted to normally collapse and close gainst the ports 5c and 6c.

The high pressure chamber 2d of the comanion unit B communicates with a port 5d be- 05 eath the elastic membrane sleeve 10d. The low ressure chamber 3d is separated by the partition from the high pressure chamber 2d and a port , normally closed by the sleeve 10d enables comunication to be made between the two chamers. A port 12d leads the pressure to the exrior of the membrane sleeve I Od, the space about is membrane sleeve being confined by the airght casing 17d. The two casings 7l and 17d ay be removably mounted, as by screw threading, upon a central block 40 and the two units B are thus combined into a single commercial device.

If the two membrane sleeves 10c and I d are identical in point of strength and tension, then the pressures in the two low pressure chambers 30 and 3d will be the same. If the strengths or tensions of the sleeves are different, then the pressures in the low pressure chambers will be proportionately different. As soon as the source of compressed gas is cut off at the nozzle 20C then the rubber sleeves I 0 and IOd will close preventing any further transfer of pressure from thecentral chambers 2c and 2d to the outer low pressure chambers 3O and 3d.

As a result after inflation the two low pressure chambers 30 and 3d are independent of one another.

Referring more particularly to Figure 8 there is shown a combined arrangement showing four of the units A', A2, B', B2. These units are mounted in series between chambers 41 and 42.

These chambers are connected by two pipes or tubes 43 and 44. In the tube 43 are disposed the unit A' and the unit B. In the other pipe there are included the unit A2 and the unit B2.

The unit B' permits the passage of gas from the chamber 42 to the chamber 41 through the tube 43, that is If the pressure in the chamber 41 is at any time lower than that in the chamber 42 The unit B2 permits the passage of fluid frorr the chamber 41 to the chamber 42 where th4 pressure in the chamber 42 is lower than that Ii 4i. The inflating nozzle 200 is connected witl the tube 44 between the chamber 41 and the uni A2. This arrangement functions as follows: When fluid under pressure is introduced at 2C it will fill the chamber 41 but be arrested by th unit B' from flowing further along in the tub or pipe 43 because this pressure has access to til outside of the membrane sleeve in the device B Therefore the pressure will aid the inherent elao ticity of the membrane sleeve to remain close Consequently the pressure will back up in tchamber 41 and extend along the pipe 44, pas ing freely through the unit A2 and also free through the unit B2 as the pressure on this sit communicates only with the interior of the mer brane sleeve and not with the exterior there until the pressure flows around to the opposi side of the partition whereupon it enters the l pressure chamber 42, and such pressure gets the outside of the membrane sleeve in the = B2 and assists the inherent elasticity of t. o5 sleeve to close the sleeve against the poi Therefore the chamber 42 will be the low pressi chamber. Pressure of course from this cha ber 42 will run to the left along the pipe 43 pa ing freely through the unit A' but being arres 00 at the unit B' because this pressure must lift membrane sleeve and it cannot do so against inherent tension of the sleeve and the gres pressure existing upon the outside of that sle In other words the pressure upon the inside of membrane sleeve in the unit B' has been red& over that reecived through the nozzle 2O0 by vil of the unit B2 but there has been no diminu of this pressure through the chamber 41 and u the outside of the membrane sleeve in the ?0 B'. The difference in pressure between 4! 42 will thus be governed by the strength of membrane sleeve in the unit B2.

Flow in the pipe 43 is only permitted in direction indicated by the arrow as the un! will prevent flow in the opposite direction as already explained.

In the companion pipe 44 flow will only be permitted in the opposite direction as indicated by the arrow, the unit B2 preventing flow in the opposite direction.

The high pressure chamber is indicated at 41 and the low pressure chamber at 42 and the pressure differential between these chambers will depend upon the strength or the elastic tension of the membrane sleeve in the unit B2. The pressure in 41 must always be strong enough to open this membrane sleeve in the unit B2. If the pressure drops in chamber 42, fluid flows through the pipe 44 and the pressure drops in chamber 41. Such pressure in 41 will drop until the pressure in this side of the device no longer exceeds the pressure in the side 42 plus the strength of the membrane sleeve in the unit B2. If the unit B2 is used alone then the strength of the membrane '20 sleeve in this unit will wholly determine the pressure differential between the two chambers but by reason of the use of the unit A2 the limit in the drop of pressure in the chamber 41 can be governed so that preferably the pressure will not drop quite as much as it would if the unit B2 were used alone.

* If pressure in the chamber 41 tends to rise, the units A2 and B2 permit the flow of pressure Stowards the chamber 42. so that the difference I between the pressures in the chambers 41 and 42 remains always equal to a constant which I varies according to the strengths of the memh brane sleeves in the two units. If the pressure t in chamber 42 tends to rise while still remain- :3i ing lower than the presure in chamber 41, no le action will take place in the device as the lower e pressure on the side 42 cannot pass through the e unit B' owing to the superior pressure on the Le side 4,. Of course the unit B2 will not permit . passage back from chamber 42 to the chamber 41. The same thing happens if a small drop ocd. curs in pressure in the side 41 but which drop ie is not sufficient to carry the pressure lower than s. in the side 42. When the pressure in 41 falls ly sufficiently below that in the side 42, or when de the pressure in the side 42 rises sufficiently above n- that in the side 41 to exceed the strength or tenof sion of the membrane sleeve in the unit B' plus ite the incumbent weight of the pressure upon this 5O oW membrane sleeve from the side 41, then a comto pensating.flow of pressure occurs from the side nit 42 over to the side 41. If the pressures fall be,at low the strength or tension of the membrane rts. sleeve in the unit A' this unit will close and pre- 5. re vent any flow from 42 to 41. Referring more m particularly to Figure 9, the units A', A2, B', and s B2 are arranged in the form of a cross with the ted opposite chambers indicated at 41a and 42a. The the valve stem or filling nozzle is indicated at 20z f( the and communicates directly with the chamber ter 14ia and also with the unit A2, as indicated by the arrows. After passing through the unit A2 the yve, flow is around to the unit B2 and by reason of the the wall 46 the gas is required to pass through 6 iced the unit B2 before getting into the chamber 42a.

rtue This chamber 42a communicates with the unit A' tion and through this unit A' with the unit B' in the pon opposite horizontal branch of the cross, there unit being also an imperforate wall 46 in this branch and of the cross to require the gas to flow through the the unit B' and raise its diaphragm before getting into the chamber 41a. The horizontal and the vertical intersecting partitions 47 and 48 are also it B' in the form of a cross, dividing the chambers _~_______ or passages and forming in effect the pipes c tubes 43 and 44 of Figure 8 requiring that th gases raise the membrane sleeves of the variou units before getting to the opposite sides of th partitions.

It will be obvious that various changes may bi made in the construction, combination and ar rangement of parts which could be used withou departing from the spirit of my invention an( I do not mean to limit the invention to such de. tails except as Particularly pointed out in the claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent of the United States is: 1. A device of the character described, comprising adjacent ,non-comMUnicating tubular gas chambers having ports therein opening outwardly, and an elastic sleeve encompassing said ports and having an interior space when Inflated for establishing communication between the ports, means for securing the ends of the sleeve in an air tight manner to said chambers, said sleeve normally stretched tightly over said ports and closing the same, and an enclosed gas tight mem-, ber extending about said sleeve and in communication with one of the chambers.

2. In a device of the character described, a tube with a partition dividing the same into opposite chambers, said tube having ports on opposite sides of said partition communicating internally with the two chambers and opening outwardly, and an elastic sleeve having its ends bound tightly to the tube at opposite sides of 5 said ports and being initially stretched over and closing said ports, but subject to inflation by pressure within the chambers acting through the ports to move away from the tube and from the ports, a casing having imperforate side and end walls fitted closely to said tube about the sleeve and forming an interior pressure space, said tube having a port establishing communication between said pressure space and one of the chambers.

ir 3. A pressure compensating device for use bee tween two containers of gas under pressure corns prising, two adjacent gas containing members e one for communicating with each of the two containers and each of said members having a e port opening therefrom, an elastic membrane stretched across both of said ports normally to t close the same and prevent communication thereI between and secured to the members in an air Stight manner, said 'membrane adapted to be Sopened by pressire exerted at said ports to permit communication between the members, and means for transmitting the pressure gas in one of said members to the outside of the membrane tending to maintain the membrae closed and Preventing completely Passage of gas from the one of said members.

4. In a device of the character described, adjacent gas chambers for communicating with gas containers, each of said chambers having a port opening therefrom, an elastic membrane secured in an airtight manner over said ports, and a gas tight cover over said membrane, one of said gas chambers having an opening therein communicating with the interior of said cover to transmit the pressure gas of said container to the outside of the membrane.

5. A connector for two gas holding vessels comprising adjoining tubes one for communicating with each of said vessels and each haying adjacent ports opening outwardly, an elastic sleeve covering both of said ports and secured to the tubes In an air tight manrer and adapted to be raised by pressure of gas operating through said ports to connect said ports together, and means for directing the pressure of gas in one of said tubes on the exterior of said sleeve to resist raising by pressure in the other of said tubes and to prevent raising by pressure in the adjoining tube.