SHAPE MEMORY CHAMBER FOR TIRE PRESSURE CONTROL

Abstract

A peristaltic pump chamber with shape memory for pressure adjustment in tires is provided and which is part of the tire or is adjacent to the tire wall or is a part of a vehicle wheel, in particular for tires with an inner tube, e.g. bicycle tires.

Claims

1. A chamber assembly with a shape memory for the pressure adjustment of tires, the chamber assembly comprising a chamber connected at one end to a medium delivery point and at another end to a source of a medium, the chamber comprising fibers that are installed across at least a part of a wall of the chamber (K), wherein, in a direction perpendicular to a lengthwise direction of the chamber, the chamber is closed 360°, and wherein at least some of the fibers are non-parallel to the lengthwise direction of the chamber.

2. The chamber assembly in accordance with claim 1, wherein fibers connect wails of the chamber (K) and/or the wall of the chamber (K) to a carrier of the chamber (K) and/or the fibers are placed on the carrier of the chamber (K) and/or on an inner tube (D).

3. The chamber assembly in accordance with claim 1, wherein the medium delivery point and/or the source of the medium is an interior of the tire (P) and/or an external environment of the tire (P) and/or a reservoir and/or an inner tube (D) and/or an interior of the valve and/or an interior of a regulator.

4. The chamber assembly in accordance with claim 1, wherein the medium is either air, nitrogen or another gas, or a gas mixture.

5. The chamber assembly in accordance with claim 1, wherein the fibers connect opposite walls of the chamber (K).

6. The chamber assembly in accordance with claim 1, wherein the fibers interconnect a wall of an inner diameter of the chamber (K) with a wall of an outer diameter of the chamber (K).

7. The chamber assembly in accordance with claim 1, wherein the fibers are arranged in parallel to each other.

8. The chamber assembly in accordance with claim 1, wherein the fibers create patterns and/or polygonal patterns, and/or they intersect.

9. The chamber assembly in accordance with claim 1, wherein the fibers are skewed.

10. The chamber assembly in accordance with claim 1, wherein the fibers are wavy and/or elastic.

11. The chamber assembly in accordance with claim 1, wherein the carrier of the chamber is a tire and/or an inner tube (D) and/or an ancillary structure.

12. The chamber assembly in accordance with claim 11, wherein the chamber is connected to the carrier by the fibers.

13. The chamber assembly in accordance with claim 1, wherein the fibers constitute a feature of a bridge (W) of the chamber (K) and/or of a tire (P) and/or of an inner tube (D) and/or of an ancillary structure, which prevents collapse of the chamber (K), with the exception of the effect that the tire's deformation load has on the chamber (K).

14. The chamber assembly in accordance with claim 1, wherein, under the chamber and/or as part of the chamber, there is a belt to prevent closing the chamber from below by means of the pressure of the inner tube itself.

15. The chamber assembly in accordance with claim 14. wherein the belt contains fibers.

16. The chamber assembly in accordance with claim 1, wherein the chamber is provided with a bridge that is anchored to sides of the chamber and thereby the chamber is protected against dilation.

17. The chamber assembly in accordance with claim 1, wherein the chamber comprises an inner tube which is made of an elastic material and is at least partially provided with a pattern of fibers for arresting crack propagation.

18. The chamber assembly in accordance with claim 1, wherein the chamber (K) and/or its carrier is at least partially covered with a grid for arresting propagation of cracks.

19. The chamber assembly in accordance with claim 1, wherein bridging and/or a belt and/or a pattern for arresting propagation of cracks and/or a grid is made of fibers.

20. The chamber assembly in accordance with claim 1, wherein the fibers are textile and/or metal and/or plastic and/or natural fibers and/or synthetic fibers and/or nanofibers.

Description

DETAILED DESCRIPTION

[0046] The invention will additionally be illustratively described using individual examples.

EXAMPLE 1

[0047] Chamber K with shape memory for adjusting the pressure in tire P, which comprises a part of tire P or that is adjacent to the wall of tire P and is connected at one end to the interior of tire P and at the other end to the external environment 0, is in the shape of a curved hollow channel.

[0048] If peristaltic chamber K with shape memory is attached to tire P and it is compressed towards the axis of tire P, chamber K closes based on a mutual contact between the upper and the lower walls of chamber K. The upper and the lower walls are located on different radii and they therefore have different circumference lengths. For example, if chamber K has a height of 1 mm and it surrounds the entire circumference of tire P, the difference between the lengths of the upper and the lower walls will be 2×pi×1 mm, i.e. 6.28 mm. At each revolution, therefore, shearing between the upper and lower walls in the range of 6.28 mm will occur. This shearing will create friction, thereby destroying the walls of chamber K and also generating heat.

[0049] The deficiencies mentioned above are largely eliminated by chamber K with shape memory for pressure adjustment in tire P, that constitutes a part of the tire or is adjacent to the tire wall and, in accordance with the present invention, is connected at one end to the interior of the tire or to the chamber K delivery point and at the other end to external environment 0 or to the source for the chamber. If anchoring fibers are to be guided across chamber K, with a span of 0.5 mm, for example, then the shear will only accumulate between these fibers and will not be transferred behind them. There the shear is distributed evenly along the entire length of chamber K. Also diminished is the maximum possible size of the shear. The fiber can be anchored to the opposite wall of chamber K or to a component that is connected to it. It may, for instance, be looped around chamber K to anchor together the lower and the upper walls of the chamber, or designed to intersect one wall of the chamber and to become anchored to the surrounding material. The fibers can only be connected to the components described in a portion of their length and/or of their number and then in the other portion of their length be connected to other elements that are not described here.

EXAMPLE 2

[0050] In FIG. 1.1 chamber K is placed on surface SP, which may, for example, be the inner tube of tire P or one of the actual layers of tire P or even an entirely other part that is located on the wheel. The chamber may then be covered with an additional layer, so that, for example if layer SP is actually meant to be the layer of tire P and chamber K is on it together with another layer of the tire, the external appearance of tire P does not need to be different than that of a regular tire. Chamber K, which can be viewed on the images from above, has the shape of a hollow tube, i.e. we do not see inside it.

[0051] In FIG. 1.1, the fibers that are guided across chamber K are connected both to it and to layer SP_. In FIG. 1.2, the location of chamber K is affected by deformation of the tire, which arrives into chamber K from the left and deforms and rolls ahead the chamber wall, resulting in a dilatation of fibers VL in direction from left to right. In FIGS. 1.3 and 1.4 the deformation has already progressed further and the fibers on the left side are re-adjusting. The deformation does not accumulate beyond the extent that the fibers permit. Otherwise it could happen, for example, that the deformation could accumulate for the entire period of a revolution and would be released only once per revolution in the form of shearing of the upper wall of chamber K against the opposite, lower, wall of chamber K at a single point. This would weaken this place, which would then also become a natural candidate for shearing during the subsequent revolution, and with each revolution, this trend would increase and this place would rapidly be destroyed. fibers SP, however, distribute this potential destruction across a greater part or the entire length of chamber K. This example describes a solution implemented by using a peristaltic pump; similarly, however, it is also applicable to other pumps, where the opposite walls of the pump come into a contact with each other, e.g. a diaphragm pump.

EXAMPLE 3

[0052] By default, the inner tube of the tire is produced from an elastic material. FIG. 2.1 shows the selected rectangle of the inner tube surface at the point where damage does occur, for example by puncturing. In FIG. 2.2 the puncture in the inner tube is marked by a cross, together with a dot. Since the inner tube is made of an elastic material and the pressure inside it is high, punctures spread in the form of a crack that almost immediately causes a rupture and a loss of pressure in the inner tube. This is shown in FIG. 2.3 as a freehand grey line; the crack propagates across the rectangle, and perhaps even behind it, through the surface of the inner tube. This can be prevented, however, if an adjustment of the inner tube is implemented as is shown in FIG. 2.4. In FIG. 2.4, the inner tube is fitted with a fabric or another grid that will prevent the crack from spreading. Thereby the length of the crack will reach only as far as to the nearest fiber of the grid. This is an advantageous solution, especially in combination with reinflating tires, that will gradually reinflate, compensating for the air escaping from the inner tube and if the actual inner tube also represents a carrier for a peristaltic or another type of pump, the inflated inner tube will support this pump in its working position. A similar effect can be achieved by replacing or covering the inner-tube material with a non-elastic material or a material that is resistant to crack propagation. Either the entire inner tube or only its exposed parts, e.g. the tread, can be covered. The fibers do not need to have a square pattern, as shown in FIG. 2.2 but, for example, they can also have triangular or other kinds of patterns. The fibers can also be arranged diagonally, which will ensure that the inner tube can be stretched during the filling of the tire, while if because the fibers are moving away from each other, they will still capture and define the maximum length of the crack. The fibers may also be wavy, as can be seen in FIG. 2.5, and thereby enable the stretching of the inner tube as is shown in FIG. 2.6, whereby the fibers re-adjust a little and the space between them increases, but the fibers will still define the maximum crack length (between them). The fibers may also be produced from a combination of textile and rubber materials as it is used, for example, for elastic bands that are used in clothes, that are elastic but also have a defined maximum length at which the stretching is terminated at this pre-defined length. These rubber-bands, for example, are spirally braided with a yarn and have a predetermined length.

[0053] The inner tube may also be made from inelastic or plastic materials, which ensures their essential impermeability, such as for impermeable textiles, foils, carbon and other similar types of products. This prevents any rapid deflation. or for example, in the case of using carbon, it increases its puncture resistance. An inner tube of this kind may then advantageously constitute a pump for re-inflating tires.

EXAMPLE 4

[0054] By default, the inner tube D of tubed tire P is separated from its external environment 0 by a valve, whereas the space between tire P and inner tube D is not hermetically separated from its surroundings. If the inner tube D is punctured, air from the inner tube D immediately escapes into tire P and subsequently around valve V out of the tire-rim assembly. This instant deflation is highly dangerous and represents one of the major disadvantages of tubed tires. It is possible to create tire P, which although it has an inner tube D that normally secures the hermeticality itself, the actual tire P itself is additionally hermetically separated from its external environment 0. This makes sense, especially with regard to the self-inflatable tire P, in which the inner tube D acts primarily as the carrier of a reinflatable device; in the case that any defect appears, however, this combination will have the same degree of resistance against rapid deflation as tubeless tire P.

[0055] This is achieved in the following manner. Inner tube D is fitted with valve V, which, in addition to sealing the interior of inner tube D, also hermetically separates the space between inner tube D and the cavity formed by tire P and the rim from their surroundings. In this manner, valve V has a similar sealing function as the usual valve of a contemporary tubeless tire.

[0056] Since valve V would prevent the necessary degree of inflation of inner tube D and would thereby prevent the possibility of forcing the air out of tire P, so that inner tube D could assume its proper position and fill the entire volume of tire P, the valve or the wheel assembly must be provided with an outlet that enables venting the spaces between inner tube D and tire P and the rim. After this venting, the outlet is closed and thereby prevents any further leakage of air from tire P. Closing the outlet in this manner does not hermetically seal the interior of tire P from its external environment 0 until the commencement of venting the air from the space between tire P and inner tube D.

[0057] The valve, in accordance with the present invention, may have a similar shape to that of the current tubeless valve that has the shape of a plug, which has to be forcibly drawn into its position in the rim. If, prior to the final fitting-in-place of the valve V body, there should be a leak in the side of valve V, for example, or another gap appears between the rim and the body of valve V through which air can escape, while inflating inner tube Oj_tire P will also be vented through this gap. After inflating inner tube D to the same full volume as tire P and forcing air from between inner tube D and tire P, inner tube D, by its own pressure, can insert valve V to its final position in the rim and thereby seal the entire system. The valve can also be fitted into its final position either manually or else mechanically, or it can be sealed to the rim by means of a nut with a gasket, in a similar manner as is currently used in the case of tubeless valves. It is also possible to vent the space between the tire and the rim through an additional gap or outlet, which is subsequently sealed. Air can, for example, be forced out between tire P—around its bead—and the rim, until the moment at which the pressure of inner tube D on tire P and its bead is sufficient to enable the bead to snap into its proper position in which it is sealed against the rim. The bead may also be fitted into the side of the rim, for example, with a gap or a channel that enables the air to escape and after the bead snaps into its final position this gap will disappear so that it actually no longer connects the cavity between tire P and inner tube D to its surroundings.

[0058] FIG. 3.1 depicts tire P with inner tube D and valve V. Whereas inner tube D is inflated through valve V, as is shown by the continuous arrows, the air from the wheel space around inner tube D (marked in grey) is forced out around valve V and into the atmosphere, as is indicated by the dotted arrows. FIG. 3.2 illustrates the expansion of inner tube D, as is indicated by the dashed arrows, and while valve V abuts the rim; its wall, however, is provided with a channel that continuously vents air from the space between inner tube D and tire P and rim R, as indicated by the dotted arrows. In FIG. 3.3, inner tube D already occupies almost the entire volume of tire P, with the exception of a small area located around the actual valve V; the pressure of inner tube D increases and pushes onto valve V until it is inserted into its final position (depicted in FIG. 3.4), at which point there is only a minimal amount of or no residual air between tire P and inner tube D. After tire P has been reinflated to its operational pressure, the system stabilises in the status shown in FIG. 3.5. In the event of any imminent destruction of inner tube D, the air in inner tube D escapes only into the area that is enclosed by tire P, rim R and the valve of inner tube D. This solution is advantageous if the inner tube is supplied for the tire or for the tubeless tire to specifically be the carrier of a pump device, a peristaltic pump for example, or a source of compressed air to be utilised for driving the mechanical equipment. This example describes the solution whereby the air that is forced out from the inner tube escapes around the valve, though it may, similarly and advantageously, escape from the wheel assembly through another point, if the assembly, after dispensing the requisite volume of air, has been re-sealed.

EXAMPLE 5

[0059] The applicant additionally describes in the present invention a new solution that enables inflation in both of the directions of rotation of the tire, while ensuring relief of the chamber by means of internal or external circulation whereby, with the exception of during inflating, air is transported only through the enclosed chamber or it is returned to the place from which it was taken. For example to the tire, the reservoir or to the external environment of the tire. A solution like this is shown in FIGS. 4.1 to 4.6, in which FIG. 4.1 depicts reinflating from the source, e.g. from the external environment of the tire, via a peristaltic pump and a right-hand regulator that has diaphragm B, formed in this case by a referential space with a diaphragm, but it can also be of a different type, electronic or mechanical, or utilising a vane, a blade, a spring etc.; in principle any method that arrests or slows down the flow of air through the specific inlet to the delivery point of the pump which, in this case, is a tire. If the tire - the delivery point of the pump - is underinflated, the diaphragm of regulator A closes the inlet and a vacuum is foiuied in the pump, which opens the left-hand inlet valve LW and initiates the sucking of air into the chamber and then pushes it around diaphragm B to the delivery point of the pump - to the tire - as identified by the dashed arrows. Both diaphragm A and diaphragm B attempt to eject because they both respond to the underpressure in the tire; diaphragm BA however, is moved by the air that flows from the chamber. If the regulator comprises an element that is not moved by the flowing air, it is possible to incorporate a separate one-way valve next to it, one that will release this air from the pump to the tire. A unidirectional valve of this kind can be installed for each of the regulators or for each inlet from the chamber to the tire. FIG. 4.2 depicts the scenario in the case of a properly inflated tire. The regulators' diaphragms are retracted and the air circulates in the direction indicated by the dashed arrows. FIGS. 4.3 and 4.4 show the same situation, but the wheel is rotating in the opposite direction and thereby the direction of the air-flow has also reversed, which results in the opposite engagement of the individual elements in comparison with FIGS. 4.1 and 4.2. FIGS. 4.5 and 4.6 illustrate their unification into a single regulator, in this instance with a single diaphragm; a regulator with two or more diaphragms can also fulfil a similar function, however. The tire shown in FIG. 4.5 is underinflated and the diaphragm has been ejected and this closes the left-hand inlet to the chamber. At the same time the diaphragm has been pushed aside by the air flowing out of the left-hand outlet from the chamber and air is now flowing into the tire. On the right-hand side a vacuum has formed which opens the right-hand inlet valve PW and starts sucking air from the source for the pump until the tire has been reinflated and the diaphragm has been retracted into the regulator. The regulator illustrated is not necessarily a diaphragm regulator; it may be based on a blade, be electronic, a vane, a spring or another mechanical device. Inlet valves PW and LW can be combined as a single inlet valve JVV, which may substitute one of these or be anywhere else in the circuit. Such a situation is depicted in FIGS. 4.7 to 4.9.

[0060] In FIG. 4.7, valve JW is located in a place between the original location of valves LW and PW. Also indicated is the deformation of chamber K, which is marked with grey tips that interrupt the chamber sequentially at 6 different points. In fact, this represents a single interruption of the chamber that occurs six times consecutively, with the proviso that this interruption progresses between these positions following the directions of the dotted arrows. The starting-point of the deformation is identified as ZD and its end-point is shown as KD. The delivery point of the pump (in this example the tire, although there can also be another reservoir and another delivery point) is deflated and the diaphragm of the regulator closes the right-hand inlet to chamber K.

[0061] FIG. 4.8 illustrates a situation in which the deformation has shifted from point ZD to the grey-tip points along the dotted arrow. The gas, in this example the air enclosed in chamber K, originally from between the diaphragm of the regulator and point ZO, has now expanded to the grey-tip point while its pressure reduced and a vacuum was created there with a pressure lower than that of the source for the pump. In this example the pressure of the external environment is 0, which represents 1 atmosphere. At the same time, the air that was originally present in the area between point_ZD and the current location of the tip was fed in the direction of the dotted arrow to the left part of chamber K and additionally around regulator R to the tire.

[0062] In FIG. 4.9 the tip of the deformation has already shifted through the chamber behind the connecting point of valve JW, whereupon it came into contact with the vacuum created in this part of the chamber; the JW is opening and the pressure in this part is evened up with the pressure at the source for the pump.

[0063] In FIG. 5.0 the deformation shifts to point KD, while in the chamber to the left of it the air is additionally compressed and is then fed to the tire, while in the chamber to the right of the deformation the sucking of air through the JW continues to take place. If the deformation then leaves the chamber, as indicated in FIG. 5.1, in which the tip does not interrupt chamber K, valve JV closes and the tire pressure fills the entire chamber, as indicated by the dotted arrow, around the diaphragm of regulator R to chamber K. The volume of air in the tire and in the chamber has increased in accordance with the volume sucked-in from the surroundings, as indicated in FIGS. 4.9 to 5.0.

[0064] Another possibility is that before the deformation leaves the chamber at point KD, this deformation again affects chamber K in another area, for example in point ZD, as shown in FIG. 5.2. Until this moment, the sucking of air via the JW and its feeding into the tire has taken place as indicated by the dotted arrow by the regulator. From the termination-point of the deformation at the point KD valve the JW is closed and the pressure evens-up towards the deformation illustrated by the grey tips. The evening-up of the pressure from the tire to the chamber is indicated by a dotted arrow on the regulator R. Simultaneously, on the other side of the deformation and towards the end of the chamber closed by the diaphragm of regulator R the original vacuum still remains and thereby this area does not need to be vented again and this pump will have a greater degree of efficacy than the pump described in FIG. 5.1.

[0065] In FIG. 5.5 the deformation has already shifted and the new cycle continues and so does the compression of air in the tire.

[0066] Valve JW may also be placed differently than described in these examples; for instance, it does not need to be connected directly to the chamber that passes through the area of deformation, but it can also be closer to the regulator or to a part of one or both of the regulators. Depending on the conditions, an embodiment can be selected with the advantage that when it is placed next to one of the outlets of the chamber, in or opposite to the direction of deformation; reinflating will still function, however, regardless of the direction of rotation of the tire.

[0067] The valve is described as being unidirectional, however it can be of any type that provides the necessary features, e.g. a two-way valve, a controlled valve, a multi-way valve, the closure element, the electronically-controlled element, an electronically-controlled valve, a gate valve, an element with referential pressure, a spring, a diaphragm.

[0068] Similarly, the regulator may also comprise any similar device.

[0069] In order to ensure the bi-directional operation of the pump, it is also possible to use a simple valve together with a ball, a flap or a slide, which is moved by pumped air that closes unwanted directions and opens the desired air-flow directions. A valve of this type is shown in FIG. 5.6. The forces that are generated, for example, by means of a peristaltic pump are sufficient even in a rotating tire, to shift the element and to maintain it in the required position. The arrows in the figures show how the pumped air works with a specific element and also how the air is thereby redirected in the requisite direction and how pumping is ensured or the input to or output from a peristaltic pump, either, for example, a classic one-way pump or one with internal or external circulation, etc., but also to/from other pumps.

EXAMPLE 6

[0070] Another solution is to use a pressure-release valve. Any pump and peristaltic chamber can also be used to release air from tires; in this case the air can be pumped out of the tire in the direction of the pressure-release valve. The pressure-release valve can be set so that, for example, it switches off at a pressure of 10 atm., thereby releasing the air. If, for example, the optimum tire pressure is 3 atm. and this is exceeded to 3.1 atm., the pump will start pumping air in the direction of the pressure-release valve. At the moment when the pressure in the pump exceeds 10 atm. next to the pressure-release valve, the valve will open and the pump will drain the excess air away through it. A pressure-release valve set at 10 atm is both simple to operate and also very safe. It is not the actual tire pressure that opens it; it opens only based on the positive pressure provided by the pump. The pump can be controlled by a regulator, a diaphragm or by other means; it may be unidirectional or bidirectional and have internal or external circulation or any other peristaltic or other type of pump.

EXAMPLE 7

[0071] The invention is additionally related to the bridging of the inner tube. FIGS. 6.0a and 6.0b below illustrate the usual tubed car tires. If there is a chamber K created underneath the tread, the tread will lose part of its camber and may begin to collapse. This is illustrated in FIG. 6.0b, in which tire pressure is acting internally on all its walls, with the exception of the tread where the chamber K is located. The pressure on the tire walls sets these sides apart, while, on the other, it pulls the tread down, thereby inadvertently closing chamber K. This can be prevented by the solution described belo.

[0072] In FIG. 6.1b, in this example of a bicycle, a chamber K is created on inner tube D. Thereby, however, the original tire tread would lose the support of inner tube D and would therefore collapse, as shown in FIG. 6.1b. This collapse would be caused by the pressure of the inner tube on the walls of tire P, whereby the tread is pulled down and at the same time flattens and expands in width. This kind of collapse can be avoided by bridging chamber K, which is anchored to the sides of the chamber and thereby protecting the chamber against becoming dilated. The bridge may have the shape of the arch that in this case also retains the arched shape of the tread. However, the chamber, in accordance with the tread, can have any shape. Beneath the actual chamber a belt is then created, that by the pressure of the actual inner tube D prevents closing chamber K from below. The belt ensures that the inner tube in the place of chamber K does not exceed the diameter equal to, or smaller, than the lower diameter of chamber K. FIG. 6.2a shows bridging W above the chamber anchored at the points that are marked X, with a full arched vault above the bridge that is formed beneath the tread. Chamber K has so far been illustrated excluding the places of deformation caused by the road and the chamber has been open. In FIG. 6.2b the chamber is deformed through contact with the road in the direction of the arrows until this deformation causes the desired closing of chamber K by the deformation of the tread and the camber towards the interior of chamber K.

EXAMPLE 8

[0073] The peristaltic chamber in the wall of the tire can be a source of the initiation and propagation of cracks that endanger the operational life of tires. The solution is a chamber K created in a part that is physically separated from the structure of tire P. By means of this separation the crack is then arrested. This can be seen in FIG. 7a. Another solution is that of forming a chamber K in a part connected with the tire, though a barrier preventing the propagation of the crack, such as a textile wall, foil or other barrier material inserted between the parts, which will either redirect the crack or halt it. This can be seen in FIG. 7b.

[0074] The examples describe using vehicle tires; however their advantages can be useful in any machines that use air-filled tires, including such stationary machinery as lifts, conveyor belts on which the belts are stretched on tires, etc.

[0075] Industrial Utility

[0076] In accordance with this invention, the chamber with shape memory for the pressure adjustment of tires will find its application in the manufacturing of new tires as well as for the adjustment of existing tires, for both passenger and utility vehicles.