GB1561701A - Creation of Inventions and Patents with Artificial Intelligence

GB1561701A – Inner tube assembly for a pneumatic tyre
– Google Patents

GB1561701A – Inner tube assembly for a pneumatic tyre
– Google Patents
Inner tube assembly for a pneumatic tyre

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Publication number
GB1561701A

GB1561701A
GB29506/76A
GB2950676A
GB1561701A
GB 1561701 A
GB1561701 A
GB 1561701A
GB 29506/76 A
GB29506/76 A
GB 29506/76A
GB 2950676 A
GB2950676 A
GB 2950676A
GB 1561701 A
GB1561701 A
GB 1561701A
Authority
GB
United Kingdom
Prior art keywords
primary tube
tube
primary
housing
pockets
Prior art date
1975-07-18
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)

Expired

Application number
GB29506/76A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

UNIROYAL

Original Assignee
UNIROYAL
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1975-07-18
Filing date
1976-07-15
Publication date
1980-02-27

1976-07-15
Application filed by UNIROYAL
filed
Critical
UNIROYAL

1980-02-27
Publication of GB1561701A
publication
Critical
patent/GB1561701A/en

Status
Expired
legal-status
Critical
Current

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Classifications

B—PERFORMING OPERATIONS; TRANSPORTING

B60—VEHICLES IN GENERAL

B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES

B60C5/00—Inflatable pneumatic tyres or inner tubes

B60C5/20—Inflatable pneumatic tyres or inner tubes having multiple separate inflatable chambers

B—PERFORMING OPERATIONS; TRANSPORTING

B60—VEHICLES IN GENERAL

B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES

B60C5/00—Inflatable pneumatic tyres or inner tubes

B60C5/20—Inflatable pneumatic tyres or inner tubes having multiple separate inflatable chambers

B60C5/24—Inflatable pneumatic tyres or inner tubes having multiple separate inflatable chambers the walls of the chambers extending transversely of the tyre

Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC

Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

Y10T137/00—Fluid handling

Y10T137/7722—Line condition change responsive valves

Y10T137/7837—Direct response valves [i.e., check valve type]

Y10T137/7869—Biased open

Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC

Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

Y10T152/00—Resilient tires and wheels

Y10T152/10—Tires, resilient

Y10T152/10495—Pneumatic tire or inner tube

Y10T152/10522—Multiple chamber

Y10T152/10576—Annular chambers

Description

PATENT SPECIFICATION
( 11) 1 561 701 ( 21) Application No 29506/76 ( 22) Filed 15 Jul 1976 ( 19) ( 31) Convention Application No 7522609 ( 32) Filed 18 Jul 1975 in ( 33) France (FR) ( 44) Complete Specification published 27 Feb 1980 ( 51) INT CL 3 B 60 C 5/06 ( 52) Index at Acceptance B 7 C IA IG ( 54) INNER TUBE ASSEMBLY FOR A PNEUMATIC TIRE ( 71) We, UNIROYAL, a corporation organized under the laws of France, having an office at Clairoix, Oise, France do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to an inner tube assembly for a pneumatic tire, and has for its objective the provision of an assembly that, when mounted in a tire will give that tire a “run-flat” capability and will hold the tire beads against the wheel rim flanges.
According to the invention an inner tube assembly for a pneumatic tire comprises an annular flexible primary tube designed to lie axially between and in contact with the beads of the tire when the assembly is mounted in the tire, a primary valve connected to and communicating with the interior of said primary tube, secondary inflatable means having a radially inner wall which radially surrounds the radially outer wall of said primary tube, secondary valve means interconnecting the interiors of said primary tube and said secondary inflatable means, and a substantially inextensible flexible annular band extending circumferentially around the radially outer wall of said primary tube for limiting the radial expansion of said primary tube upon inflation thereof over at least a portion of the axial extent of said primary tube whereby said primary tube expands axially to bear against the beads of the tire, said secondary valve means remaining open and intercommunicating the interiors of said primary tube and said secondary inflatable means for as long as there remains an equilibrium of pressure therebetween, and said secondary valve means including closure means for pneumatically isolating the interiors of said primary tube and said secondary inflatable means from one another when there occurs a pressure drop in said secondary inflatable means relative to said 45 primary tube.
The outer diameter of the primary tube in its inflated mounted condition may be greater than the maximum diameter of the outer flanges of the wheel rim 50 Preferably the secondary inflatable means comprises a plurality of inflatable balloonlike pockets abutting one another in a circumferential array around said primary tube, and the secondary valve means comprises a plura 55 lity of valves each of which is associated with a respective one of said pockets.
In another form of the invention the secondary inflatable means includes a further circumferential array of abutting pockets 60 surrounding said primary tube means and axially adjacent to the aforesaid circumferential array of pockets The two arrays may abut each other substantially along the equatorial plane of the tire 65 In a further embodiment the secondary inflatable means can be made up by a plurality of annular tubes placed side by side around the primary tube, and each circumferentially surrounding part of the axial width of the 70 primary tube.
In yet another embodiment the secondary inflatable means can be a single secondary tube radially surrounding the primary tube.
In order to inflate the pneumatic tire in 75 accordance with the present invention, all that is required is to feed compressed air through the primary valve (which may be conventional) of the primary tube, thereby bringing about the simultaneous inflation of 80 0 _ 1 561 701 the primary tube and inflatable means Conversely, for the purpose of deflating the pneumatic tire, all that is needed is to push down manually the inside pin of the conventional primary valve, thereby permitting the air to escape from the primary tube The air in the secondary inflatable means will simultaneously escape into and thence out of the first inner tube via the secondary valve means.
If the secondary inflatable means of the pneumatic tire comprises only a single secondary tube radially surrounding the primary tube, the moment such secondary tube is punctured, it deflates completely The secondary valve means immediately closes at such time as a result of the sudden pressure drop in the secondary tube During travel, the deflated secondary tube flattens against the primary tube which continues to remain inflated The wheel, provided with such a pneumatic tire, can therefore continue to travel on a road by resting exclusively on the inflated primary tube even if the outer diameter of the latter is below the edge diameter of the rim flanges (that is to say, it does not project radially outside beyond the level of the rim edges) This occurs because the flattened secondary tube forms a protective pad or cushion.
If the secondary inflatable means of the pneumatic tire comprises two secondary annular tubes placed side by side around the primary tube, the puncture of one of the secondary tubes effects a very rapid or practically instantaneous automatic closing of the secondary valve when associated with that tube, to prevent the primary tube from deflating As the punctured secondary tube deflates, the other (or adjacent) secondary tube expands and fills the space cleared by the deflated and punctured secondary tube.
As a result, the wheel can continue to run on a pneumatic tire inflated practically at standard pressure In the event that the other secondary tube is also punctured, the pair of flattened secondary tubes act as a pad or cushion between the inflated primary tube and the road.
If the secondary inflatable means of the pneumatic tire comprises one complete circumferential row of small inflatable pockets each having an associated valve, the puncture of one or of several of the pockets causes a rapid automatic closing of the or each valve associated therewith, thereby insulating the primary tube from each punctured pocket to prevent the deflation of primary tube Gradually with the deflation of each punctured pocket, the adjacent or neighboring pockets situated circumferentially on either side of the punctured pocket expand one toward the other until they join one another by clamping, pinching, or wedging between themselves the punctured pocket that has flattened If a plurality of successively adjacent pockets become punctured, the two closest non-punctured pockets that are still intact and that are situated on either side or at each end of the set of punctured pockets expand in order to take up the space that has become vacant therebetween 70 In either instance, the wheel can continue to travel on a pneumatic tire that remains substantially normally inflated If all of the pockets of the circumferential row are punctured, the wheel can still continue running 75 on the primary tube that remains inflated.
If the secondary inflatable means of the pneumatic tire comprises first and second circumferential arrays of pockets, then, in the event of a puncture of all the pockets in one 80 array, the valves cooperating therewith close automatically and the entire other array of non-punctured pockets expands crosswise to fill the volume left vacant by the punctured pockets that have flattened The wheel can 85 therefore continue to operate on a pneumatic tire that remains inflated.
In all of the preceding instances of puncture, the primary tube remains inflated as well as in tight bilateral contact with the beads of the 90 pneumatic tire which are wedged by the primary tube against the opposite flanges of the wheel rim The tire therefore is prevented from separating from the wheel rim.
One and the same primary tube of a given 95 size and one and the same number of pockets of a given size forming the secondary inflatable means are capable of association with several different sizes of pneumatic tires having the identical rim-edge diameter but different cross 100 sectional widths (for wheels having the same rim width) In this way, it is possible to use an identical inner tube assembly with for instance, pneumatic tires having the following different standard sizes: 105 S Rx 13 ” S Rx 13 ” (S speed up to 180 km/h) R radial carcass) In the mixed nomenclature system, in 110 accordance with accepted standards, the standardized rated pneumatic tire sizes referred to above comprise two digits, the first one of which expresses in millimeters the approximate size or maximum width of the meridian section i 1 i 5 of the tire bead (mounted on a standard rim and inflated to rated pressure), and the second one of which in inches designates the exact diameter under the bead, or the bead edge diameter 120 With a growing cross-sectional width of the pneumatic tire, the pockets aforementioned expand axially so as to fill out the available inner volume of the pneumatic tire in question.
However, according to standard practice, 125 pneumatic tires of increasing cross-sectional width are generally mounted on rims of increasing width Thus, for instance:
(a) a 135 x 13 or 145 x 13 pneumatic tire is mounted onto a 4 J 13 or 4 B 13 rim 130 1 561 701 (that is to say, having a width of 4 inches).
(b) a 155 x 13 or 165 x 13 pneumatic tire is mounted onto a 4 1/2 J 13 rim (that is to say, having a width of 4 5 inches).
(c) a 175 x 13 pneumatic tire is mounted onto a 5 J 13 rim (that is to say, having a width of 5 inches).
In these cases of wider rims, the primary tube expands axially to a greater extent so as to efficiently hold the beads of the pneumatic tire against the edges of the rim; however, the outer diameter of said primary tube remains substantially fixed because of the presence of the substantially inextensible band.
It should be pointed out that, in the case of the standardized rated rim sizes referred to above by way of example, the first numeral expresses the width (in inches) between the rim flanges, (that is to say, the width from one flange to the other), whereas the second numeral expresses the bead seat diameter (in inches).
In the case of pneumatic tires having a bead seat diameter of 14 inches, it is necessary to manufacture a new primary tube of 14 ” However, one can use identical small pockets to form the secondary inflatable means, thereby achieving substantial savings and simplifying considerably storage space since all that is required is to store only one size of the pockets.
A punctured pocket can be readily replaced by a new one at a cost that is less tan than that of an entire inner tube The punctured pocket can also be repaired at a later date It is even possible to replace the spare wheel of a passenger car or of a motor vehicle by a supply of spare pockets carried along in the car boot.
The present invention, by creating special inner tubes constituted respectively of a primary tube and secondary inflatable means that are very simple in manufacture, makes it possible to provide a pneumatic safety tire that is substantially less costly than the pneumatic safety tires presently known in the art and, thereby, more profitable not only in the sale of new pneumatic tires, but also in the sale of spare pockets.
Moreover, the present invention is extremely reliable and efficient in operation and is, therefore, of great dependability Finally, a pneumatic tire fitted with an inner tube assembly in accordance with the invention is far lighter in weight than the pneumatic safety tires presently known in the art, which has a favorable effect on the tire’s handling pattern, its road-holding ability, travelling comfort, and its effect on the vehicle.
The present invention will be better understood, and other objects, characteristics, details and advantages of the invention will become more readily apparent upon reading the description that follows with reference to the drawings, in which:
Figure 1 is a fragmentary view of a crosssection along the equatorial sectional plane defined by the line I-l of Figure 2, showing a peripheral portion of the rim of a vehicle wheel (the rim edge or center having been 70 omitted) fitted with a pneumatic tire and an inner tube assembly in accordance with one embodiment of the invention and illustrated in its undamaged inflated condition; Figure 2 is a fragmentary cross-sectional 75 view along a meridian or axial plane section defined by the line 1 I-11 of Figure 1; Figure 3 is a fragmentary cross-sectional view of a primary tube illustrated in its free or unmounted inflated condition; 80 Figure 4 is a view similar to that of Figure 2, showing however only the primary tube, the secondary inflatable means having been omitted to more clearly illustrate the shape assumed by the primary tube; 85 Figure 5 is a cross-sectional view on a larger scale of the encircled detail III of Figure 2, representing a valve along a longitudinal or axial section and in its automatic open position; and 90 Figure 6 is a view similar to that of Figure 1 showing, however, a pocket of the pneumatic tire in a punctured state caused by a nail that has pierced the tread.
Referring now to Figures 1 and 2, these 95 show a pneumatic tire referred to generally by the reference character 1 mounted on a wheel rim generally designated by the reference 2, which is assumed to be supported by a wheel axle (not shown) The embodiment so illustra 100 ted is for instance preferably at least substantially symmetrical with respect to the equatorial plane The pneumatic tire 1 is constituted by a carcass 3 comprising in particular a tread 4 and a pair of beads 5 by 105 means of which the tire 1 is mounted on the wheel rim 2 Within the tire is an inner tube assembly comprising a radially internal primary tube 6 (defining a main chamber) as well as an assembly 7 of secondary inflatable pockets in 110 a circumferential array around the primary tube and defining auxiliary chambers.
The wheel rim 2 is preferably, but not necessarily, of the well type comprising a well 8 in the central portion, two tire bead retaining 115 flanges 9, and two bead seats 10 connecting the well 8 of the rim with its flanges 9 (see Figure 2).
The primary tube 6 is made of a material that is pliable or flexible and is mounted in 120 the well 8 of the rim 2 It presses against the entire wall surface of said well 8 and partially overlaps the bead seats 10 so that it comes to rest in the normally inflated condition of the primary tube 6, on the inner faces of the 125 beads 5 of the pneumatic tire 3 so as to wedge said beads against the rim flanges 9.
The primary tube 6 is provided with a standard or ordinary inflation valve 11 projecting laterally through an appropriate opening in 130 11 O 1 561 701 the rim 2 The valve 11 is conventional and mounted in a conventional manner on the primary tube 6 The valve 11 contains, in its body, a helicoidal return spring valve mechanism tending to close the valve automatically the moment the external pressure does not exceed the internal pressure of the primary tube 6 The valve 11 also opens and is kept open by an external pressure the moment the latter exceeds the internal pressure of the primary tube 6 The mechanism comprises furthermore a pin accessible from the outside following removal of the valve cap, making it possible to open the valve manually and deflate the primary tube 6.
The secondary assembly 7 completely and contiguously surrounds the primary tube 6.
The assembly 7 is composed of at least one circumferential row of small inflatable balloonlike pockets 12 which are preferably similar or identical, but independent of one another and arranged contiguously and juxtapositioned in series in the normally inflated state as illustrated in Figure 1 Each one of the pockets 12 is made of a pliable or flexible and elastically expandable and contractable material.
In the normally inflated state, each one of the pockets 12 has at least substantially the shape of a segment of a tubular ring or a hollow torus closed at each extremity by a perpendicular terminal wall that is for instance substantially radially directed and flat Thus, its longitudinal cross-sectional profile following the equatorial plane of the pneumatic tire of following a plane perpendicular to the geometric axis of rotation of the wheel or revolution of the tire, has a configuration substantially of that of a concave and curvilinear isosceles figure.
In the normally inflated state, each one of the pockets 12 abuts against the internal wall surface of the pneumatic tire 3 as well as the radially outer wall surface of the primary tube 6 Each is also in continuous uniform contact through its terminal or extreme transverse opposite walls with the respective corresponding adjoining wall of the two adjacent pockets pockets 12 between which it is mounted.
Each one of the pockets 12 may have extreme transverse walls having a convex bulging shape in the inflated free state.
In order to guarantee the tightening and the clamping of the tire beads 5 against the rim flanges 9, it is necessary that the axial width of the primary tube 6 in the free inflated state be greater than the internal spacing distance of said beads mounted onto the rim, so that the latter are adequately forced against the rim flanges In order to improve this locking effect of the tire beads by the primary tube 6, its capacity to expand radially is limited so that its capacity to expand axially is enhanced.
For this purpose, the primary tube has, in its inflated free state, a configuration that is at least substantially oval in the axial direction.
This configuration is achieved in particular by means of a wall portion having a substantially inextensible band limiting the radial expansion of the central peripheral wall in the radially external crown area This particular band can 70 be constituted for instance by a reinforced or twill texture fabric that is substantially inextensible Such a reinforcing band is incorporated into the wall of the primary tube 6 or attached onto the same in the form of a strip 75 constituting a belt or a collar extending in an equatorial zone, for instance substantially symmetrical with respect to the equatorial plane.
Figure 4, from which there has been omitted 80 the assembly 7 of secondary pockets, illustrates the configuration that would actually be assumed by the primary tube 6 in its mounted inflated state, in the absence of the pockets 12.
One can note in particular that the direct 85 bearing surface of the primary tube 6 against the tire beads 5 is wide because the radial expansion of the tube is limited by the band which forces the tube 6 to expand axially and form a pair of external lateral bulges 37, 90 one on each side of the band 35.
Finally, in order to have the primary tube 6 conform closely to the internal cross-sectional shape of the rim, in its inflated mounted state, it is advantageous that it exhibits, in its 95 unmounted inflated state as shown in Figure 3, a radially internal wall portion 38 having a convex shape (set during the manufacturing process), that mates with that of at least a portion of the well 8 of the rim with which 100 it must be in contact in its inflated, mounted state.
Each one of the pockets 12 is connected, preferably removably, to the primary tube 6 by at least one individual valve 13 serving, on 105 the one hand, to establish or to temporarily interrupt the communication between the pocket 12 and the primary tube 6 and, on the other, to attach the pocket 12 associated therewith to the primary tube 6 To this end, each 110 valve 13 is permanently connected to the primary tube 6, each said valve being arranged in the wall of the radially external crown area of the primary tube 6 and situated at least in part inside the latter by penetrating substan 115 tially radially into the latter through the wall of the said primary tube 6 Each valve 13 and the radially internal wall of its associated pocket 12 is respectively provided with mutually cooperating leakproof connecting means 120 As shown more particularly in Figure 5, each valve 13 comprises, in a known manner, a metal valve body 14, made for instance of coated brass, mounted or embedded by molding in a tubular tip 15 made of rubber 125 which traverses the wall of the primary tube 6.
Each valve 13 further comprises at its radially external end a crosswise enlarged portion 16 constituting a foot, a flange, or a similar edge, which is bonded to the exterior surface 130 1 561 701 5 of the primary tube wall 6.
Inside the hollow body 14, which forms a tubular housing, there is mounted the mechanism of the valve 13, which comprises a hollow sleeve 17 made for instance of steel that has been inserted into the hollow body 14 and screwed by a radially external threaded end portion into a threaded portion 18 of the axial borehole of the hollow body 14 Leakproof tightness between the smooth or unthreaded external lateral portion of the sleeve 17 and the corresponding smooth internal wall of the borehole of the hollow element 14 is provided by an annular gasket 19 mounted inside a circumferential groove provided in the surface of the external wall of the sleeve 17 As a variant, the ring 19 could be mounted inside an annular groove of the borehole 20 of the body 14 and be in elastic or compressed contact with the external lateral surface of the sleeve 17.
The terminal surface of the radially internal end of the sleeve 17 constitutes with the edge of its borehole an annular valve seat 21 against which a plug-like element 22 is capable of axially engaging The element 22 is of prestoconical shape and is biased toward the primary tube 6 and an open position (as shown on Figure 5) by at least one return spring, for instance a helicoidal compression spring 23 coaxially surrounding a valve stem 24 The spring 23 is braced at its radially internal end against the valve element 22 and at its radially external end against an internal annular shoulder 39 of the borehole 25 of the sleeve 17 The valve stem 24 extends from the valve element 22 in a radially external direction and is movable axially along the bore 25 in the sleeve 17 The bore 25 is of sufficient diameter such that there remains an annular clearance around the stem 24 up to an opening 40 at the external end of the bore 25 The bore 25 inside the sleeve 17 therefore constitutes the path for the passage of air through the valve 13 in two opposite directions The valve stem 24 ends at its radially external extremity in an enlarged head portion 41 that is for instance pristo-conical in shape The head portion 41 constitutes an abutment that is engageable with the edge of the opening 40 The head portion 41 is preferably provided with one or a plurality of longitudinal grooves 42 allowing for the passage of air when the head portion 41 abuts against the sleeve 17.
The spring 23 must be calibrated so that its force is relatively weak so that the valve 22 can close under the effect of a critical excess of pressure of, for instance, 0 3 atmospheres within the primary tube 6 with respect to the pressure prevailing in the associated pocket 12 as a result of a puncture of the latter The valve 13 is in this manner relatively sensitive to variations of the pressure in its associated pocket 12.
Each of the aforesaid connecting means between a given pocket 12 and the primary tube 6 is preferably constituted by two connectable linkage elements such as a pawl locking arrangement, or a screw-type assembly with the said elements comprisng for instance a male and a female element that can be joined 70 or fitted into one another The male part can be provided on the pocket and the female element can be provided on the primary tube.
According to the latter embodiment illustrated, the aforesaid female connecting element 75 is formed by the radially external portion of the body 14 of the valve 13 that is joined to the wall of the primary tube 6 That portion is provided with an internally threaded bore 26 that is substantially coaxial with the valve 13 and 80 communicates with its mechanism The bore 26 is accessible and open on its radially external side while the aforesaid male connecting element is constituted by a metallic hollow metal or similar tubular sleeve 27, made for instance 85 of brass, that is externally threaded substantially along its entire length The sleeve 27 is bonded to and leakproof with the radially internal wall of the associated pocket 12 and projects radially inwardly from the outside wall of the 90 pocket.
The sleeve 27 can be screwed completely into the bore 26 extending substantially coaxially with the inside bore 20 of the valve body 14 as an aligned prolongation of the latter In 95 the completely screwed-in position, the sleeve 27 abuts with the crosswise terminal face of its radially internal end against an annular packing or gasket 28 placed against an internal shoulder of the bore 26 100 The axial borehole 29 of the sleeve 27 communicates with the inside cavity of its associated pocket 12 via an orifice 30 traversing the wall of the pocket and having a diameter corresponding substantially to that of 105 the borehole 29 of the sleeve 27 The sleeve 27 is preferably embedded, in particular by means of molding, with one extremity in a rubber base 31 that is bonded to the outer rubber surface of its associated pocket 12 The 110 base 31 is vulcanized onto the sleeve 27 By the same token, the rubber tip 15 is vulcanized on the body 14 of the valve 13.
Because of this arrangement, each one of the pockets 12 can be readily mounted onto and 115 dismantled from the primary tube 6 simply by screwing or unscrewing the sleeve 27 by rotating the pocket in one direction or the other It will be understood that the components of the valve 13 and the sleeve 27 120 could be made of plastic instead of metal The moment the sleeve 27 is screwed completely into the body 14 of the valve 13, the base 31 presses at least against the end cross-face of the radially external end of the body 14 as 125 illustrated in Figure 5 It ought to be noted that the axial bore 20 of the valve body 14 has a pristo-conical intermediate inner wall 32 converging toward the radially internal side and situated substantially at the level of the gasket 130 1 561701 1 561 701 19 Thus, by introducing and by screwing the sleeve 17 into the valve body 14 from the outside through the opening 26, the gasket 19 is gradually tightened against the conical wall 32 Moreover, the rubber tip 15 covers or overlaps the solid annular portion of the terminal cross-surface at the radially internal end of the valve housing 14 thereby functioning as a protector pad or bead to prevent a possible contact by the hard or metallic internal end of the valve 13 with the radially internal opposite wall of the primary tube 6 in the event of a collapse or a flattening of the primary tube 6.
The mode of operation of the pneumatic safety tire fitted with an inner tube assembly in accordance with the present invention is described below assuming that, originally, the pneumatic tire is in a completely deflated state.
In order to inflate the pneumatic tire, all that is required is to introduce compressed air through the ordinary inflating valve 11 During inflation the pressure difference between the primary tube and each pocket will be less than the critical excess so that the valves 13 are held open by their return springs 23 and the compressed air can inflate simultaneously the primary tube 6 and all of the small pockets 12.
At the end of the inflation operation, the moment the proper inflation pressure has been attained, the valve 11 is separated from the source of compressed air to which it has been connected, and all of the valves 13 remain open as a result of the pressure equilibrium prevailing within the primary tube 6 and within the pockets 12, all of which communicate with the primary tube 6 and, accordingly, with one another through the primary tube.
The primary tube 6, therefore, assures at all times an even or uniform distribution of the pressure within the various pockets 12, thereby automatically balancing out local variations of pressure that are likely to arise during travelas a result of the local deformations which the pockets 12 may experience one after the other as a result of a partial flattening the moment the corresponding portion of the tread 4 comes in contact with the ground The configuration of the assembly is then in general the one illustrated in Figure 1 where one can see in particular three successive complete pockets 12 a, 12 b, and 12 c.
In the event of a puncture of a pocket 12, for instance the pocket 12 b, as a result of the perforation of its radially external wall by a nail or a similar sharp-tipped element 33 that has pierced the tread 4 (see Figure 6), the pocket 12 b that has been affected deflates.
The deflation is accelerated or assisted by the bilateral compression experienced by the pocket 12 b between the two adjacent pockets 12 a and 12 c which tend to expand one toward the other.
In Figure 6, the initial configuration (prior to perforation) of the pockets 12 a, 12 b, and 12 c, as shown on Figure 1, is illustrated by discontinuous dash-dot lines.
The deflation of the punctured pocket 12 b causes a rapid drop of pressure in the latter, thereby creating a pressure difference greater than the critical excess and surging valve 13 b The greater pressure in the primary tube 6 overcomes the opposing force of the return spring 23 and forces the valve element 22 back into its closed position against its seat 21 The punctured pocket 12 b is in this manner isolated from the primary tube 6 so that the latter cannot be deflated Gradually with the deflation of the pocket 12 b, the two neighboring or adjacent pockets 12 a and 12 c expand (owing to the elastic nature of their rubber walls) toward one another by pushing or forcing back the opposite corresponding walls of the pocket 12 b The final configuration of the pockets 12 a, 12 b, and 12 c has been illustrated by the solid continuous lines in Figure 6 In this way, the volume that has initially been taken up by the pocket 12 b in the inflated state prior to puncture is finally taken up (substantially except for the volume of the material constituting the pocket, following a puncture, by the adjacent extreme portions of the neighboring pockets 12 a and 12 c.
The valves 13 that are respectively associated with the other pockets 12 remain open thereby permitting the primary tube 6 to continue in effective operation By the same token, if fo any reason an air lead occurs in a pocket 12 (for instance, its wall has become porous), the valve 13 associated with such defective satellite balloon closes automatically and the adjacent or neighboring pockets 12 expand simultaneously toward one another as discussed above The tire can, thus, continue to be used in an operative condition.
In order to replace a punctured or defective pocket, it is necessary to first deflate the pneumatic tire 1 by opening and by keeping manually opened the valve 11, thereby bringing about the simultaneous deflation of the damaged pockets 12 through their associated valves 13 and the primary tube 6 One can then dismantle pneumatic tire 3 from the wheel rim 2 and remove the primary tube 6 and the pockets 12 from the tire The defective pocket can then be removed by turning it so as to unscrew its associated sleeve 27 from its associated valve 13 One can then proceed with replacing the defective pocket with a new pocket.
It is obvious that the moment a pocket 12 has been punctured, the overall inflation pressure of the pneumatic tire becomes slightly reduced In the event that all of the pockets are punctured, the pneumatic tire can still operate on the road by resting on its primary tube 6 which remains inflated at a pressure which is however slightly below the initial inflation pressure as a result of the leak occurring during the period of closing of the 1 561 701 valves As a matter of fact, the moment a pocket 12 becomes deflated as a result of a puncture, the mass of air contained in said pocket is lost, thereby bringing about a reduction in the remaining inflation pressure.
Indeed, the respective volumes of the other pockets increase through expansion of the latter, said increase in overall volume continuing to correspond to the initial volume of the punctured pocket.
Assuming that the pneumatic tire comprises a number N of pockets 12, the rated air inflation pressure PO corresponds initially to a total inside volume of V + n(v) (where V denotes the volume of the primary tube 6 and v the volume of each pocket 12) At the moment a pocket 12 is punctured, the balance of the volume V + (n-l)v, which had been at the initial pressure P 0, increases by the value of the volume v of the punctured pocket to become equal to an overall volume V + n(v) at a new pressure Pl (lower than P 0) which, according to Mariotte’s Law, is equal to:
V + (n-l)v P, = PO V + n(v) Following a puncture of i pocket, the residual pressure therefore becomes:
V + (n-i)v P, = PO V + N v

Claims (9)

WHAT WE CLAIM IS:

1 An inner tube assembly for a pneumatic tire, said assembly comprising an annular flexible primary tube designed to lie axially between and in contact with the beads of the tire when the assembly is mounted in the tire, a primary valve connected to and communicating with the interior of said primary tube, secondary inflatable means having a radially inner wall which radially surrounds the radially outer wall of said primary tube, secondary valve means interconnecting the interiors of said primary tube and said secondary inflatable means, and a substantially inextensible flexible annular band extending circumferentially around the radially outer wall of said primary tube for limiting the radial expansion of said primary tube upon inflation thereof over at least a portion of the axial extent of said primary tube whereby said primary tube expands axially to bear against the beads of the tire, said secondary valve means remaining open and intercommunicating the interiors of said primary tube and said secondary inflatable means for as long as there remains an equilibrium of pressure therebetween, and said secondary valve means including closure means for pneumatically isolating the interiors of said primary tube and said secondary inflatable means from one another when there occurs a pressure drop in said secondary inflatable means relative to said primary tube.

2 An inner tube assembly as claimed in claim 1, in which the secondary inflatable means comprises a plurality of inflatable balloon-like pockets abutting one another in a circumferential array around said primary tube.

3 An inner tube assembly as claimed in 70 claim 2, in which the secondary valve means comprises a plurality of valves each of which is associated with a respective one of said pockets.

4 An inner tube assembly as claimed in 75 claim 2 or claim 3, in which each of said pockets is separate from the others and is detachable from said primary tube.

An inner tube assembly as claimed in any one of claims 2, 3 and 4, in which each of 80 said pockets is made of an expandable material.

6 An inner tube assembly as claimed in any one of claims 2 to 5, in which said secondary inflatable means includes a further circumferential array of abutting pockets 85 surrounding said primary tube means and axially adjacent to the first said circumferential array of pockets.

7 An inner tube assembly as claimed in any one of the preceding claims, in which the 90 secondary valve means comprises one or more valves, each of which includes a tubular housing having first and second coaxially opposite open ends, an elongate rod supported for endwise movement in said housing and defining with the 95 interior of said housing an annular space, said rod including first and second enlarged heads coaxially spaced from one another over a distance that is greater than the spacing between said opposite open ends of said 100 housing, spring means surrounding said rod between said heads, a first end of said spring means being engageable with said first head of said rod, the second end of said spring means being engageable with the interior of said 105 housing adjacent to said second open end of said housing, said spring means urging said rod into a position at which said second head engages said second open end of said housing, said second head being diametrically larger 110 than said second open end and including groove means for intercommunicating the exterior of said housing with the interior thereof when said second head is engaged with said second open end, said first head being diametrically larger 115 than said first open end of said housing and held remote from the latter by said spring means when the second head engages said second open end of said housing, said first head confronting the interior of said primary 120 tube and being movable in response to pneumatic pressure thereagainst into engagement with said first open end of said housing to close said first open end and pneumatically isolate the interior of said primary tube from that of 125 the secondary inflatable means.

8 An inner tube assembly as claimed in claim 7, and including support means for securing said housing in intercommunicating relation with the interiors of said primary 130 1 561 701 tube and secondary inflatable means, said support means including an open ended hollow projection secured to said primary tube, a hollow internally threaded sleeve fixedly confined in said projection, said housing having external threads threadedly associated with a threaded portion of said sleeve, and a cylinder secured at one end to said secondary tube means and having external threads engaging with internal threads of said sleeve to hold the cylinder coaxial with said housing.

9 An inner tube assembly as claimed in any one of the preceding claims, in which the substantially inextensible band is sufficiently narrow axially of said primary tube to enable said primary tube to circumferentially expand radially beyond said band on either side of said band.
An inner tube assembly substantially as herein described with reference to the accompanying drawings.
URQUHART-DYKES AND LORD Chartered Patent Agents, Agents for the Applicants.
11th Floor, Tower House, Merrion Way, Leeds L 52 8 PB -and11th Floor, St Martin’s House, Tottenham Court Road, London WIP OJN.
Printed for Her Majesty’s Stationery Office by MULTIPLEX techniques ltd, St Mary Cray, Kent 1979 Published at the Patent Office, 25 Southampton Buildings, London WC 2 1 AY, from which copies may be obtained.

GB29506/76A
1975-07-18
1976-07-15
Inner tube assembly for a pneumatic tyre

Expired

GB1561701A
(en)

Applications Claiming Priority (1)

Application Number
Priority Date
Filing Date
Title

FR7522609A

FR2318041A1
(en)

1975-07-18
1975-07-18

PNEUMATIC SAFETY BANDAGE FOR VEHICLE WHEELS AND ITS COMPONENT ELEMENTS

Publications (1)

Publication Number
Publication Date

GB1561701A
true

GB1561701A
(en)

1980-02-27

Family
ID=9158103
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

GB29506/76A
Expired

GB1561701A
(en)

1975-07-18
1976-07-15
Inner tube assembly for a pneumatic tyre

Country Status (7)

Country
Link

US
(1)

US4054169A
(en)

BE
(1)

BE843062A
(en)

CA
(1)

CA1047380A
(en)

DE
(1)

DE2632406A1
(en)

FR
(1)

FR2318041A1
(en)

GB
(1)

GB1561701A
(en)

IT
(1)

IT1071132B
(en)

Cited By (2)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

GB2118492A
(en)

1982-04-09
1983-11-02
Pirelli
Inner tube and apparatus for its manufacture

GB2361679A
(en)

1999-08-26
2001-10-31
Raymond A E Baron
Tyre inner tube

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Assignee
Title

US4193429A
(en)

1976-06-24
1980-03-18
Uniroyal
Pneumatic tire inflation and method

FR2430323A1
(en)

1978-07-03
1980-02-01
Uniroyal

COMPOSITE SAFETY TUBE FOR VEHICLE WHEEL AND COMPONENTS THEREOF

FR2554058A1
(en)

1983-11-02
1985-05-03
Sillam Serge
Air chamber with several interchangeable and independently inflatable elements for the event of a puncture in one of them

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1987-10-02
1989-12-05
Ho I Chung
No-flat tire insert

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1997-12-02
Ho; I-Chung
No-flat tire and no flat tire insert

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1995-08-23
1998-01-20
Obermeyer; Henry K.
Connection system for reinforced composite structures

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1995-11-15
1997-05-21
Rudolf Schevenhoven
Novel construction for producing and inflating pneumatic tyres

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2001-02-16
2003-07-08
Chesterfield E. Walrond
Segmented tire

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2012-01-13
2014-11-04
Bear Corporation
System and method of securing a pneumatic tire to a rim

CN103241067A
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2013-04-28
2013-08-14
山西惠丰机械工业有限公司
Bundled anti-explosion car inner tube

CN103213457A
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2013-04-28
2013-07-24
山西惠丰机械工业有限公司
Primary-secondary type anti-explosion car inner tube

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2013-09-24
2018-11-13
Chengdu Youyang Electromechanical Product Design Co. Ltd.

Multi-chamber tire

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2013-10-04
2014-01-22
谢珍文
Puncture-resistant scratch-resistant wheel inner tube

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2014-02-21
2015-08-27
Hutchinson S.A.
System including pressurized load cells

CN204249735U
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2014-11-27
2015-04-08
王荣平
A kind of novel inner structure tire of ballonet automatic inflating

CN106494160B
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2016-12-03
2017-11-17
东莞市皓奇企业管理服务有限公司
The application method of trouble-proof tire anti-drip valve

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2017-05-18
2019-02-12
Peram LLC
Tire insert

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(en)

2018-08-16
2018-12-21
安徽奥丰汽车配件有限公司
A kind of automobile rubber air bag

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2019-10-14
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江苏华梓车业有限公司
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2021-11-03
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1904-12-01
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1975

1975-07-18
FR
FR7522609A
patent/FR2318041A1/en
active
Granted

1976

1976-06-17
BE
BE168018A
patent/BE843062A/en
unknown

1976-07-08
US
US05/703,339
patent/US4054169A/en
not_active
Expired – Lifetime

1976-07-09
CA
CA256,669A
patent/CA1047380A/en
not_active
Expired

1976-07-15
GB
GB29506/76A
patent/GB1561701A/en
not_active
Expired

1976-07-16
IT
IT68796/76A
patent/IT1071132B/en
active

1976-07-19
DE
DE19762632406
patent/DE2632406A1/en
active
Pending

Cited By (2)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

GB2118492A
(en)

1982-04-09
1983-11-02
Pirelli
Inner tube and apparatus for its manufacture

GB2361679A
(en)

1999-08-26
2001-10-31
Raymond A E Baron
Tyre inner tube

Also Published As

Publication number
Publication date

IT1071132B
(en)

1985-04-02

US4054169A
(en)

1977-10-18

DE2632406A1
(en)

1977-01-20

CA1047380A
(en)

1979-01-30

FR2318041B1
(en)

1978-03-17

BE843062A
(en)

1976-12-17

FR2318041A1
(en)

1977-02-11

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