US2107596A

US2107596A - Pressure compensating device for multiple gas chambers

Info

Publication number: US2107596A
Authority: US
Inventors: Bourdon Pierre Marcel
Original assignee: Compagnie Generale des Etablissements Michelin SCA
Current assignee: Compagnie Generale des Etablissements Michelin SCA
Priority date: 1934-06-12
Filing date: 1936-09-30
Publication date: 1938-02-08
Anticipated expiration: 1955-02-08
Also published as: BE407837A; FR774496A; GB445643A

Description

BERs

Feb. 8, 1938. P. M. BoURDoN PRESSURE COMPENSATING DEVICE FOR MULTIPLE GAS CHAM Original Filed April 19, 1935 2 Sheets-Sheet l I Feb. 8, 1938. P. M. BouRDoN BERs n u f u Original Filed April 19, 1955 f Snventor umqn/ Patented Feb. 8, 1938 UNITED STATES PATENT OFFICE Serial No. 17.365,

PRESSURE COMPEN SATING DEVICE FOR MULTIPLE GAS CHAMBERS Pierre Marcel Bourdon,

to Michelin et Cie., Cle

a corporation of France 17,365. ber 30, 1936, June 12, 1934 Paris, France, assignor rmont-Ferrand, France,

19, 1935, Serial No. application Septem- 103.462. In France 5 claims. (ol. 152-12) The present invention relates to improvements in pressure compensating devices for multiple gas chambers and is a division of application led April 19, 1935, and in one i instance the invention relates more particularly to a device for eq-ualizing pressure between the air chambers of twin automobile tires.

Another object an improved c l maintain a const of the invention is to produce ompensating device which may ant pressure difference between two gas or air chambers where it is desirable that the pressure be not at predetermined The invention equalized but be maintained pressure differences. l has for a further object the i production of a compensating device for the purpose indicated which is made up of simple parts grouped in a simple organization.

forms a unit whi The device ch may be used either alone or in any appropriate numbers or combinations.

With the foregoing and other objects in view,

the invention will b e described more particularly in the following specification and more particularly pointed out in the In the drawings, in

noted by the sam appended claims. which like parts are dee reference characters throughout the several views,

Figure 1 is a diagrammatic view of a unitary compensating device constructed in accordance with the present Figure 2 is a. in Figure l.

Figure 3 is a view similar commercial deviceshowing the tion of Figure 1.

invention. section taken on the line 2-2 to Figure 2 with the inflated. diagrammatic view showing a the device.

cross section taken through a unitary construc Figure 6 is a similar View showing a commercial application iof the modified device according to Figure 4.

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 iiexible or elastic membrane sleeve I0 bound securely, as indicated at 'I and 8, to the metal orv other tube I at opposite sides of the ports 5 andi.

The device may be contained within a collar or casing 9 allowing ample room for the membrane I 0 to expand outwardly from the outer wall of the tube I. The membrane III, 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 5 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 I0 is applied closely or tightly about the tube I thus closing the ports 5 and 6. 'Ihis is illustrated in Figure 2 by position I.

Whenever the chamber 2 contains pressure in excess of the contractile strength of the membrane sleeve I0 it will act through the port 5 upon s-uch membrane thus inflating the membrane I0 by rst causing it to bulge locally away from in the ports 5 and 6 are in communication. In

this position communication between the chamgas iiows freely

bers

2 and 3 is established and from chamber 2 into chamber 3 until pressuresV in the two chambers become equal.

pressures have been thus equalized if the pressure in one chamber, at any time, for any reason Figure 7 is a cross section showing a combination unit.

Figure 8 is a grouping of a plurality of the Figure 9 is a sectional view diagramma-tic view showing a units, and

showing a commer-- :ai adaptation of the grouping of the plurality :f the units.

Referring more 1nd for the prese n there is shown iazcd generally at -:

hambers

2 and 3 yhamber 2 may pace of one aut becomes greater than that in the companion chamber, the gas ows from that chamber to the other chamber through the equalizing device un-A til stability of pressures is restored. 'Ihis will go on automatically maintaining a condition of equality of pressures of the two

chambers

2 and 3. below the predetermined her will flow over to dist tain pressure equality.

its. Of course should a the tires thus completely the chamber After the On the other hand, should the pressure fall L maximum in any chain-V ber, then the pressure from the companion chamribute the loss and main-- l occurred by reason "a considerable distance 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.

In emergencies such as this the elastic membrane sleeve i 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 sui'iicient pressure in the remaining tire to properly support the vehicle without endangering the tire itself. thus enabling the vehicle to be run on this remaining tire for 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 I0 will first collapse against the port i of the chamber 3 in which the heavy fall in pressure has In other wordsl the device will shown in Figure 2 before lt returns to the position I." The distention of the membrane sleeve I0 in response to the pressure within either chamber will depend upon the tension inherent in the rubber sleeve lli and also upon the port area or diameter of the ports and 3. From the moment the membrane sleeve Iii closes to the position shown in Figure 2, communication is prevented between the two

chambers

2 and 3 and the defiating chamber can continue to defiate without affecting the pressure condition of its companion chamber.

In practice the following effects will be secured from the use of the improved compensating device.

l. When inflating, the two chambers or tires will be caused to receive equal pressures.

2. The two chambers will remain at equal pressures provided such pressures exceed a predetermined minimum which minimum depends upon the tension of the rubber sleeve I0 land the cross sections or port areas of the

ports

3 and 3.

3. If the pressure in one of the chambers falls below this predetermined pressure minimum the pressure in the companion chamber ceases to drop.

The collar or tance from the expansion and contraction of the membrane sleeve i0 but such collar l acts as a stop to arrest any undue iniiation of the membrane iii. It also reinforces and supports the membrane I0 in case of excessive inflation to avoid injury or bursting of the membrane sleeve. The intethe collar I and the membe open at the ends of the device 3 is located a desired disfree 'collar to the atmosphere so that there is no coniined air space interfering with the free movement of the membrane sleeve III.

Referring more particularly to Figure 4 in which a modified form of device indicated generally at B is provided. a similar arrangement of tube i,

chambers

2 and 3, partition 4.

ports

3 and 3 and membrane sleeve i0 is provided: but in this case instead of providing a"collar. an enclosed casing 3* is fitted tightly to the tube i at the opposite ends of the membrane sleeve i0 and this casiin'gl 3l houses a connned volume of air about the membrane sleeve Iii.

The end walls 3 of the casing 3l are provided with out-turned flanges or bearing portions 0b which are fitted in an air-tight manner about the pipe or tube i. The confined space within the casing 3l is placed in communication with one of the chambers, for instance the chamber 3, by an orifice or port l2. By reason of this arrangement it will be seen that the chamber 3 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 iii it will expand such sleeve away from the tube i in the manner already described in connection with Figures l, 2, and 3. and shown in Figure 4 so that ultimately the port 3 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 uid which is admitted to chamber 3 will pass through the orifice i2 and into the confined space of the enclosed casing 3l about the exterior surface of the rubber membrane sleeve iii. Thus the sleeve i0 will be subject to the pressure of chamber 2 from within and of the pressure of chamber 3 from without. The sleeve I0. as previously explained, is of rubber stretched over the tube l so that it inherently seeks a position fitting tightly against the tube i and its

ports

5 and 8.

This elastic tension or contractile stress within the rubber sleeve i0 is augmented or supplemented by the external pressure in the enclosed casing 3* acting on the outside of the sleeve.

within the chamber ports l and 3 will remain open and there be a flow of gas chamber 3. It will membrane sleeve I0 will contract and close the

ports

5 and 3 before any equality of pressure is established in chamber 3 and therefore chamber 3, in the arrangement shown in Figure 4, can never reach the same pressure as in chamber 2. The pressure differential would depend upon the elastic strength or stress of the membrane sleeve i0 and this may be selected so as/to give the desired result. Considered in another way the pressure in chamber 3 will always be less than that in chamber 2 by the amount necessary to open the membrane sleeve I0. When pressure is cut-oi from being introduced into the chamber 2. counter-pressure within the enclosed casing 3l will promptly cause the membrane sleeve i0 to close against the ports.

If at any time after inflation there should occur a( pressure drop in chamber 3, or a rise in chamber 2. so as to disturb the pressure dif-y ference, the membrane iii will again open tc permit flow from 2 to 3 to compensate for the variation.

This flow will continue until the inherent tenthis sleeve to iiow of the fluid will then of course be prevented. If pressure falls in the chamber 2 or rises in the chamber 3. obviously the membrane sleeve l0 will remain closed against the ports 6 and G and no movement of the gas from the chamber 3 to chamber 2 will be permitted.

In short, the device B shown in Figure 4 will have as its effect to maintain between chambers 2 and 3 a normal difference of pressure which will depend. all other things being equal. on the initial or inherent 'tension of the. sleeve l0. If the pressure becomes lower in the low pressure chamber 2' must 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 sufllcient pressure in chamber 3 is established to permit closing ol the valve I0, 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 constant. 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 3n represent twotubes communicating at their outer ends separately with two chambers or tires or the like. At their inner ends the tubes conneet with ducts or channels Ila and Mb which are separated by the partition 4a. The channel I 4e communicates at I9 with a passage I8 in the valve stem or inating nozzle 20. The channels Ma and Idb are made in a body 30 of metal or other suitable construction in which is also constructed the partition 4a. The channels Ida and I4b on opposite sides of the partition 4 respectively lead beneath a rubber membrane sleeve IIJa which normally shrinks or contracts against the ports 5a and 6a in the outer ends of the channels. The sleeve In may be held in place by a ring I5 and a nut I6 and the valve stem 20 may be also held in place by an apropriate washer and nut 3| screwed on to the same and bearing against an enclosing cap I'I. However the enclosing cap I'I will merely form a protection for the rubber sleeve I Ila 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 inating hose is connected with the valve stern 20 and air or other fluid is pumped through the passages I8 and Ida 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 Illa, this sleeve will be expanded away from the ports a and 6a and the pressure will ow from one channel IIIn into the other channel IIIb 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 sleevey Illa open. In other words the equality of pressure is maintained so long as conditions are normal. If an excessive deation occurs in one of the chambers, the de ation in the other chamber is limited by the initial or inherent tension of the sleeve Illa which may be chosen as strong as one wishes. The elastic strength or tension of the rubber out oi` which the sleeve I0a is made may be very strong or comparatively weak. Where it is of great strength, high pressures will be required to raise the same from the ports 5 and 6. Therefore where a high strength rubber sleeve IIIa is employed and a severe drop in pressure is caused in one of the chambers, the other chamber will only give up a small portion of its pressure to that of zhe decient chamber owing to the fact that after i comparatively small drop in pressure from the nigh pressure chamber, the strong membrane ileeve Il)n will close thus preventing the loss of my further pressure in such high pressure chamier.

On the contrary if it is desired that equality of 3 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 I Ila 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 5 and Se 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 chamber, or the tube connecting the high pressure chamber with the device, is designated at 2b. 'I'hese tubes connect with the casing 3|)b and with chambers to opposite sides of the partition 4b. The hollow valve stem is represented at b and 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 I0h which is contained within a casing Ilb surrounding the membrane Il)b and having a tight t at 23 with the casing h. The casing has an orifice or port I2b establishing communication between the low pressure chamber 3b and the chamber conned by the casing Hb.

'I'his casing I'Ib makes an air-tight t with the casing at 23 and also at 3 Ib.

A device according to this construction has the following advantages:

(a) The two chambers 2b and 3b are inatcd to unequal pressures depending on the tension of the membrane IIIb.

(b) If the 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 the valve sleeve Illb 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.

'I'he chamber 2c of one of the units B is divided by a partition 4C from the low pressure chamber 3c, which low pressure chamber communicates by means of a port or annular channel I2c with the confined space on the exterior of the elastic membrane sleeve IOC.

An air-tight casing Il serves to conne the gas about the membrane sleeve and this membrane sleeve is adapted to normally collapse and close against the ports 5c and 66.

The high pressure chamber 2d panion unit B communicates with a port 5fl beneath the elastic membrane sleeve IIld. The low pressure chamber ild is separated by the partition 4d from the high pressure chamber 2d and a port 6d, normally closed by the sleeve IllI enables cornmunication to be made between the two chambers. A port I2d leads the pressure to the exterior of the membrane sleeve Id, the space about this membrane sleeve being confined by the airtight casing I'Id. The two casings I'Ic and I'Id may be removably mounted, as by screw threadof the coming, upc-n a central block 40 and the two units E are thus combined inte a single commercial de vice.

I! the two membrane sleeves |0c and I0d are identical in point of strength and tension, then the pressures in the tufo low pressure chambers 2 and 0 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 20 then the rubber sleeves I0 and I0d will close preventing any further transfer of pressure from thecentral chambers 2 and 2d to lthe outer

low pressure chambers

3 and 3.

As a result after inaticn the two

low pressure chambers

2 and 3 are independent of one another.

Referring more particularly to Figure B there is shown a combined arrangement showing rour of the units A', A, B. B. These units are mounted in series between chambers 4| and 42. These chambers are conneetedby two pipes or tubes 40 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 E permits the ypassage of gas from the chamber 42 to the chamber 4l through the tube 4I. that is if the pressure in the chamber is at anytime lower than that in the chamber 42. The unit 13z permits the passage of uid from the chamber 4| to the chamber 42 where the pressure in the chamber 42 is lower than that in 4|. The intlating nozzle 20 is connected with the tube 44 between the chamber 4| and the unit A2. This arrangement functions as follows:

When uid under pressure is introduced at 20 will fili the chamber 4| butbe arrested by the unit B' rom flowing further along in the tube or pipe 43 because this pressure has access to the outside of the membrane sleeve in the device B'. Therefore the pressure will aid the inherent elas ticity of the membrane sleeve to remain closed.

Consequently the pressure will back up in the. chamber 4i and extend along the pipe 44, passing freely through the unit A2 through the unit B3 as the pressure on this side communicates only with the interior ofthe membrane sleeve and not with the exterior thereof until the pressure flows around to the opposite side of the partition whereupon it enters the low pressure chamber 42. and such pressure gets to the outside of the membrane sleeve in the unit IBl and assists the inherent elasticity of that sleeve to close the sleeve against the ports. Therefore the chamber 42 will be the low pressure chamber. Pressure of course from this charnber 42 will run to the left along the pipe 43 passing freely through the unit A' but being arrested at the unit B' because this pressure must lift the membrane sleeve and it cannot do so against the inherent tension of the sleeve and the greater pressure existing upon the outside of that sleeve. In other words the pressure upon the inside of the membrane sleeve in the unit B' has been reduced over that reecived through the nozzle 20 by virtue of the unit B2 but there has been no diminution of this pressure through the chamber 4I and upon the outside of the membrane sleeve in the unit B'. 'Ihe difference in pressure between 4| and 42 will thus be governed by the strength of the membrane sleeve in the unit B2.

IIilow in the pipe 4l is only permitted in the direction indicated by the arrow as the unit B' and also freely will prevent ow 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 4| and the low pressure chamber at 42 andthe pressure differential between these chambers will depend upon the strength or the elastic tensicri of the membrane sleeve lnlthe unit B2. The pressure in 4| must always be strong enough to open this membrane sleeve in the unit B2. If the pressure drops in chamber 42, `iuid flows through the pipe 44 and the pressure drops in chamber 4I. Such pressure in i 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 sleeve in this unit will wholly determine the pressure differential between the two chambers but by reason of the use of the unit A.z the limit in the drop of pressure in the chamber 4| 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 4| tends to rise, the

units A' and B2 permit 4the now of pressure towards the chamber 42.so that the difference between the pressures 42 remains always equal to a constant which varies according to the strengths of the membrane sleeves in the two units. If the pressure in chamber 42 tends to rise while still remaining lor-Jer than the presure in chamber 4|, no action will take place in the device as the lower pressure on the side 42 cannot pass through the unit B' owing to the superior pressure on the Of course the unit B2 will not permit passage back from chamber 2 to the chamber 4|. The same thing happens if a small drop occurs in pressure in the side 4| but which drop is not sufficient to carry the pressure lower than in the side 42. When the pressure in 4| falls sufficiently below that in the side 42, or when the pressure in the side 42 rises sufficiently abc-ve that in the side 4| to exceed the strength or tension of the membrane sleeve in the unit B plus the incumbent weight of the pressure upon this membrane sleeve from the side 4|, then a compensatingilow of pressure occurs from the side 42 over to the side 4|. If the pressures fall below the strength or sleeve in the unit A this unit will close and prevent any flow from 42 to 4|. Referring more particularly to Figure 9, the units A', A2, B', and B2 are arranged in the form of a cross with the opposite chambers indicated at 4|a and 42a. The valve stem or filling nozzie is indicated at 20t and communicates directly with the chamber 4 le and aiso with the unit A2, as indicated by the arrows. After passing through the unit A2 the new is around to the unit B2 and by reason of the wall 45 the gas is required to pass through the unit B2 before getting into the chamber 42a. This chamber 42 andthrough this unit A' with the unit B in the opposite horizontal bran-eh of the cross, there being also an imperforate wall 46 in this branch of the cross to require the gas to flow through the unit B and raise its diaphragm before getting int-o the chamber 4|f. The horizontal and

vertical intersecting partitions

41 and 48 are also in the rorm of a cross, dividing the chambers in the chambers 4| and tension of the membrane communicates with the unit A' I do not mean to limit the invention to such details except as particularly pointed out in the claims. Y

Having thus described my invention, what I claim and desire to secure by Letters Patent of the United States is:

1. A device of cation with one of the chambers.

2. In a device of the character bers.

3. A pressure compensating device for use be tween two containers of gas under pressure comprising, two adjacent gas containing members preventing completely passage of gas from the one of said members.

4. In a. device of the character described, adjacent