MXPA00005598A - Antenna for radio transponder - Google Patents

Abstract

An annular apparatus (26) embedded in a substantially nonconductive elastomeric material (22) located within the toroidal region of a pneumatic tire (10) or on the radially outer side of the wheel rim on which a pneumatic tire is mounted. The apparatus may be incorporated in a ring of elastomeric material attached to the rim. The apparatus is coaxially positioned with respect to the tire or wheel and preferably is embedded in the tire at its equatorial plane (EP), and includes a radio-frequency transponder (28) including an integrated circuit chip;and optional sensors in the chip or associated with the chip;the integrated circuit chip of the transponder has at least the capacity to transmit data relating to tire or wheel identification. The antenna comprises a composite of an electrical conductor and a rubber matrix wherein the composite is capable of substantial elongation.

Description

ANTENNA FOR TRANSPONDER RADIO BACKGROUND OF THE INVENTION This invention relates to an annular apparatus, which includes an antenna for electronically transmitting tire or wheel identification or other radio frequency data. The apparatus includes a radio frequency transponder comprising an integrated circuit chip having data capacity, at least sufficient to retain identification information for the tire or wheel. Other data, such as the inflation pressure of the tire or the temperature of the tire or wheel at the transponder site, can be transmitted by the transponder together with identification data. As evidenced by the references described below, it is known in the art to employ an annular antenna to transmit, by radio frequencies, data from a transponder contained within the structure of a tire or tire and wheel assembly. In practice, however, it is very difficult to do this with an antenna built into the tire during the course of its manufacture. Both radial and superposed layer tires undergo a substantial diametrical enlargement during the course of their manufacture. The tires of superposed layers expand diametrically when they are inserted in a curing mixture, typically they have a bladder that forms the raw tire in the toroidal shape of the mold circumscribing it. Radial layer tires are subjected to diametral expansion during the construction of the tire or the forming process, and to an additional diametral expansion during the course of curing. Any electronic circuits coupled to an annular antenna built into the tire must be able to ensure that its electrical connections survive this diametral enlargement of the tire during its manufacture. In addition, the annular antenna must be able to survive the repeated deformations that occur during tire use. The electrical connections between circuit elements and antenna systems can not be easily made during the course of manufacturing the tire. It has been proposed in the past to use conductive rubber as an antenna material in the side wall or under the surface in contact with the filter of a tire. The difficulty with providing said conductive rubber in a tire annularly is that the length of the trajectory of an annular antenna is substantial, particularly if it is located in the diameter of the sidewall of the tire or portion of contact with the floor, and the resistivity in the conductive rubber compounds, as a function of the amount of conductive carbon black becomes substantially constant at a very high level for activation of the transponder, particularly in medium truck tires. Accordingly, the annular apparatus, including a tire identification transponder or other data, such as pressure or temperature at the transponder site, is suitable, adjust the diametral enlargement of the tire during the construction and curing process. Also, the antenna must be able to survive the rigors of tire operation and there must be no danger of antenna failure due to wire breakage by technical instructions, and the electrical resistance must be less than the maximum amount tolerable for a function of the transponder in the tire or wheel environment. It is convenient to interrogate or read the data contained within or transmitted by the transponder in any position around the circumference at 360 ° of the tire. Transponders typically require a capability of parallel combinations with an antenna coil to supply the circuit to the resonant frequency transmitted by the scanner or reader. Conveniently, this should not be necessary or at a minimum, it should not require selection of the capacitance value for each manufactured tire.

A convenient feature of the transponder apparatus in a tire is that it is capable of transmitting tire pressure data if a pressure sensor is employed as a whole. Also, it is convenient that the transponder be able to transmit information regarding the temperature of the tire at the transponder site. The annular apparatus used as a transponder mechanism to transmit data from a tire or wheel of economic technique both with the weight of materials and labor required to incorporate it into the structure of a tire or wheel. Another problem encountered by prior art apparatuses is the testing procedures to which the tires are subjected before retreading. In truck tires, which are retreaded two, three or more times, it is necessary that transponder and associated antenna systems be able to survive high-voltage inspection routinely used during the retreading of these tires. In the use of the high-voltage test, chains that have high voltage creep over the interior of the tire in an attempt to create a high-voltage arc through any nail holes or other perforations that may be present in the tire. of the tire as a result of its use before retreading. This voltage, which is typically in the Order of 40,000 volts pulsed, you can easily bow to an antenna system that provides data readability at 360 °, and damage the transponder. A further convenient aspect of an antenna system designed to be used as a transponder in a tire is the limitation of the transmission range. To avoid interference with other signals or inability to detect data coming from tires placed adjacent to each other, the transmission should be limited to "near field" created by the interrogator, whether it is a portable reader, a "forward" reader above ", or a reader" on board "the vehicle where a tire or wheel is mounted. The most accurate and effective way to provide tire pressure and temperature verification devices is to include the device within the structure of a tire or wheel structure. Devices that are designed to connect to the tire lip and wheel have been problematic and their accuracy is questionable. On the other hand, since a tire undergoes high pressures and temperatures during its construction, many devices that theoretically will verify the temperature and pressure of a tire can not survive the process of tire construction. According to this, the challenge of the technique is to provide a sufficiently small device that does not alter the properties of the tire in use and is sufficiently strong so that it is not destroyed during the construction and curing process of the tire or during the operation of the tire after it has been mounted on a vehicle. An object of the invention is to provide an apparatus that can be constructed in a tire, small enough so that it does not have a noticeable effect on the operation of the tire and is strong enough to withstand the millions of deformations to which a tire is subjected during its use. in a vehicle. Other objects of the invention will be apparent from the following description and claims. DESCRIPTION OF PREVIOUS TECHNIQUE Tire safety indicator means have been provided in the prior art to indicate when the floor contact portion of a tire is worn to the point where the contact portion with the floor or the tire must be replaced. . See for example De Cicco in the U.S. Patent. No. 3,770,040. As the art has advanced, systems for verifying tire pressure and the like have been proposed wherein a transmitter and receiver are mounted on a vehicle body, and magnetically coupled inducer and inducer circuits are transported on the vehicle wheel to provide Verification of tire pressure of the vehicle as described by Alien in U.S. Pat. No. 4,588,978. Other devices for verifying the tire pressure have been proposed by Galasko et al., In the U.S. patent. No. 4,578,992, which illustrates a coil mounted on a tire that forms, with a capacitor, a passive oscillatory circuit. The circuit is energized by pulses supplied by a coil placed outside the tire and attached to the vehicle, and the frequency in the passive oscillatory circuit is varied with the tire pressure due to changes caused to the capacitance value of the capacitor. The frequency of the circuit is detected by a coil placed outside the tire and attached to the vehicle. Milheiser, in the U.S. patent. Do not. 4,730,188 illustrates the use of a passive integrated transponder that is connected to or embedded in an item to be identified and excited by an inductive coupling of an interrogator. Fiorletta, in the patent of the U.S.A. Do not. ,289,160 illustrates a wireless tire pressure verification device, which warns a low pressure driver on one or more tires. Fiorletta, illustrates that a pressure transducer, transmitter and antenna are integrally housed and mounted on the stem of the tire.

When the pressure transducer detects a pressure below a pre-selected pressure, the transmitter broadcasts a radio frequency signal that, upon detection by a receiver mounted on the vehicle, warns the user. In a preferred embodiment, the transmitter is a device that is interrogated periodically by an RF signal from a transmitter in the vehicle. In PCT application O90 / 12474, it is illustrated that electronic transponders can be embedded within or on vehicle tires and electromagnetically driven by signals from an interrogating coil. The request indicates that the transponder responds to drive by producing a shifting frequency that is modulated with synchronization pulses and identifying digital information and may also be used to include information regarding the condition and environment of the tire. Hettich et al., In the U.S. patent. No. 5,140,851, illustrate a circuit assembly for verifying air volume in vehicle tires that allows correction for tire temperature. The patent states that the measurement value of temperature and pressure of the tire is measured by a rotary receiver on the wheel, which is verified and the data is fed to a correction circuit that also receives a plurality of correction parameters. A corrected value for the temperature or for the air pressure in the tire is transmitted at the output of the correction circuit as a function of the connection parameters. - PCT application WO92 / 20539 provides an abnormal tire condition warning system comprising a housing, a band for mounting the housing in the tire lip, a detector for verifying the condition within the tire, circuits operatively connected to the tire. detector for generating radial signals indicative of the condition of the tire, a source of energy operatively connected to the circuits, a centrifugal switch and a receiver for the radio signals. Durm et al., In the patent of the U.S.A. No. 4,911,217 discloses a system for radio frequency tire identification hg an integrated circuit chip transponder. Pollack et al., In the U.S. patent. No. 5,161,975, illustrates a tire hg an integrated circuit transponder comprising a coiled antenna of small circumscribed area, as compared to the area circumscribed by the face of the tire, and acting as a primary winding of a transformer. The coil is planar in shape, and when placed between the inner liner and the shell layer of the Pneumatic can include a pressure detector. Brown et al., In the U.S. patent. No. 5,218,861, illustrates a tire hg an integrated circuit transponder hg an antenna coupled by electric or magnetic fields to the face of the tire. Definitions The following definitions are provided to facilitate the reading of the specification and the understanding of the invention. "Heterodyne" refers to the difference frequencies and additional sums produced by mixing two sinusoidal alternating current sources. "Band space voltage shift" refers to the temperature dependent energy of an electron in a semi conductor as described by Fermi. "Transmitter" refers to a radio frequency transmitter. "Receiver" refers to a radio frequency receiver. "Integer" refers to a transmitter-receiver decoder combination. "Induction / inductor" refers to the effect of varying field, magnetic to cause induced voltage in a conductor.

"Flow lines" refers to magnetic intensity and magnetic intensity vector direction. "Passive oscillatory circuit" refers to a combination of series or parallel connection of capacitor-inductor pairs. "Frequency" refers to periodic rate of change of source of AC voltage. "Transponder" refers to an RF energy receiver, capable of transmitting coded information to an "explorer" interrogator. "Equatorial plane (EP)" refers to the intercepted plane on the tire center line. "Radially" refers to a radial line from a tire axis to a tire circumference and its parallel lines. "Peak farad (pf)" refers to an electric charge storage unit and is equal to 1x10"12 farads COMPENDIUM OF THE INVENTION An annular apparatus is provided for electronically transmitting identification data of wheel or tire or others. it comprises a transponder, which includes an integrated circuit chip and at least first and second electric conductors coupled to the chip.

Externally induced, it causes the data to be sent out sequentially from the chip as a voltage that appears between the first and second conductors. An antenna, which together with the transponder has an annular configuration and is coaxial with the tire or wheel. The antenna comprises a rubber matrix composite and a third electrical conductor. The first and third conductors as a whole, and the second and third conductors as a whole are partially embedded in a conductive rubber matrix, whereby the electrical resistance between the first and second electrical conductors is the resistance of the third electrical conductor. There is no direct electrical contact between the first and second conductors, and in the illustrated mode, they are connected to each other through the circuit board and through the antenna. The apparatus is substantially circumscribed by non-conductive rubber and is located within the toroidal region of the tire, or on the radially outer side of the tire. The transponder may optionally include a pressure sensor having a force response sensing surface positioned to respond to pressure changes within the toroidal region of the tire, or on the radially outer side of the wheel rim. embeds in materials not conductors to avoid electrical conduction or significant derivation between the first and second different conductors through the third conductor. In a preferred embodiment, an apparatus for electronically measuring and storing tire data is provided. The apparatus comprises a transponder with a flake having a capacity at least sufficient to retain and / or transport tire pressure data, tire temperature data and retain identification information for a tire. The transponder is a signal generator comprising the flake and first and second conductors. In the construction of a tire, the longitudinal direction of the flake (and any cable terminals that may extend from the flake) is / are oriented at an angle with respect to the equatorial plane of the tire corresponding to the angle of the reinforcement cords of the carcass layer of the carcass layer immediately adjacent to the flake. The transponder is capable of responding to predetermined signals that trigger a response signal that transmits identification and data information. A third driver, or an antenna portion comprising a composite consisting of a conductive material in a rubber matrix, and having a conformational relationship allowing 100 to 300% elongation of the compound. In the illustrated embodiment, the antenna portion is placed around EP of a tire, in which it is incorporated. Optionally, the rubber matrix may comprise a conductive rubber having a resistivity of 0.1 to 100 ohms.cm. Welding may be used to connect the first and third conductors, and the second and third conductors attached, or they may be placed in electrically conductive rubber in immediate proximity to each other where the conductive rubber provides electrical contact between the transponder and the antenna, without using gaskets. of welds. The conductive rubber has a tension modulus of 21.09 to 28.12 kg / cm2 (300 to 400 psi) at 50% elongation, an elongation from 270 to 350%, a maximum traction of 126.54 to 147.63 kg / cm2 (1,800 to 2,100 psi) ), rubber adhesion / brass wire coated with approximately 50 newtons force (75% rubber coverage) and 30 minute T90 curing time. An antenna designed to receive a signal from a transmitting device to electronically activate the electronic circuit of the chip and to transmit data from its electronic circuit to a receiving device is also provided. The antenna comprises a conductive composite material consisting of a conductor in a rubber matrix, the compound preferably having a conformation ratio allowing approximately 100 at 300% elongation. The antenna is formed in a loop that substantially encircles the tire or wheel, but does not derive the first and second conductors. When a wire conductor is used, the antenna wire can be bent into a sinusoidal waveform, a helical shape, a triangular waveform or any compressive shape of similar length. Also provided is a tire comprising at least two parallel annular faces, shell layers wrapped around the faces, floor contact portion disposed on the carcass plies in a crown area of the tire, side walls disposed between the portion of the tire. contact with the floor and the faces, and a detection system placed between the shell layer and the inner lining. The detection system comprises the apparatus of the invention as described. Also provided is a rubber composition having a resistivity of 0.1 to 100 ohm.cm, comprising a non-productive portion comprising rubber (natural rubber) NR (SMR grade 5CB or better), 80 to 100 parts by weight per 100 parts. rubber (phr) of conductive carbon black, 10 to 24 phr of silica, 0 to 8 phr of tackifying agents, 0 to 4 phr of antioxidants, 0 to 6 phr of antioxonificants and 0 to 2 phr of stearic acid, and a curing package comprising steel at 2 phr of antioxidant, 5 to 15 phr of ZnO, 0 to 2 phr of accelerators, 0 to 2 phr of MgO and 1 to 5 phr of sulfur. A rubber composition having a dielectric strength of 400 to 800 volts per .0254 mm (1 mil), comprising a non-producing rubber mixture, 0 to 10 phr of low conductivity black carbon, 0 to 24 is also provided. silica phr, 0 to 20 phr of clay, 1 to 16 phr of tackifying agents, 0 to 20 phr of process oils, 0 to 4 phr of antioxidant, 0 to 6 phr of antiozoning agent and 0.1 to 2 phr of stearic acid, and a curing package comprising 0 to 2 phr of antioxidant, 0.5 to 16 phr of ZnO, 0 to 1% of MgO, 0.5 to 3 phr of accelerators and 0.2 to 5 phr of sulfur. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates a cross section of an RMT tire having the apparatus of the invention embedded in the crown of the tire. Figure 2 illustrates a cutting portion of the tire of Figure 1 as seen from the rim. Figure 3 illustrates a sectional side sectional view of the tire of Figure 1 on the equatorial plane (EP) of the tire. Figure 4 illustrates a possible mode of an antenna employed in the apparatus of the invention.

Figure 5 illustrates orientation of a transponder with its length oriented with the linear direction of the reinforcing cords of a carcass ply. Figure 6 illustrates a second possible embodiment of the antenna structure employed in the apparatus of the invention. Figure 7 illustrates another possible embodiment of the antenna structure * employed in the apparatus of the invention. Figure 8 illustrates another possible embodiment of the antenna structure employed in the apparatus of the invention. Figure 9 illustrates incorporation of a transponder and antenna into the wheel structure adjacent to a tire. DETAILED DESCRIPTION OF THE INVENTION In the technique referring to the collection of information from animated or dynamic objects that refer to tires, the tendency has been to implant a device that is capable of transmitting information and that responds to an external energy source in the tire to be identified. This is achieved by including a coil (which is capable of transporting an induced electrical current) of some kind in the implanted device. An electric current can be induced in the coil by a magnetic field produced by an interrogator as the magnetic field flux lines cut through the coil. The current produced in the coil in turn produces a magnetic field that can be read by the interrogator. The current in the coil, and the signal that is read by the interrogator, can be altered by electrical devices used to provide tire data, such as temperature and pressure detectors and these differences in the signal can be read and interpreted by the interrogator. Now with reference to Figures 1, 2 and 3, a tire 10 is illustrated incorporating a transponder 28, or signal generator, which may be employed to provide tire data such as inflation pressure within the tire, tire temperature , the depth of the contact portion with the floor and the identification of the tire. As is conventional in the art, the tire is made using at least one pair of annular faces 12, on which at least one shell layer 16 is wrapped. The bands 18 are placed on the carcass ply 16 in a crown area. of the tire, and the contact portion with the floor 20 is placed on the strips 18. Side walls 22 are disposed between the contact portion with the floor 20 and the faces 12. In the illustrated embodiment, the tire also has an inner liner 14. which is positioned radially underneath the carcass ply 16. The pneumatic illustrated is an RMT, but those skilled in the art will recognize that the apparatus of the invention may have utility in passenger tires or any tire for which data are required regarding to the history or condition of the tire. The most common tires, depending on the type, have up to four pairs of faces, up to twelve layers of carcass and up to twelve bands. In the illustrated embodiment, the transponder 28 is placed under the center of the floor contact portion, i.e. in the equatorial plane (EP) of the tire and radially below the carcass ply 16 and radially on the inner liner 14. It is considered that this location in the tire provides the most accurate data and makes the tire data more easily accessible if the tire is mounted on a vehicle or stacked in storage, since the data can be recovered by carrying the interrogator near the tire. the contact portion with the floor in any portion of the floor contact portion around the 360 degree circumference of the tire. Now with reference to Figures 2 and 3, the ability to read tire data at any point around its circumference is made possible because the antenna portion 26, a conductor is disposed on the circumference of the tire in its EP. ~~ Referring now to Figure 4, the transponder 28 is similar to that illustrated in the E.IT.A. Nos. 5,181,975 and 5,218,861 granted to The GoodYear Tire and Rubber Company, and the records of the agent of Nos. DEN 1997-194, 1997-195 and 1996-092 of common cession and provides identification data for the tire and can be used to verify pressure of the tire, tire temperature and the like. As illustrated in Figure 4, the signal generating means or transponder 28 may comprise the flake 24, the first conductor 30, the second conductor 31 and the third conductor 26, which is used to receive the interrogation signal and to transmit data in answer to the question mark. The antenna portion 26 electrically connects the first conductor 30 and the second conductor 31 through the circumference of the tire. In order to obtain a return signal of the required magnitude, and obtain a 360 degree reading around the tire, it is necessary that there is no direct electrical connection between the first conductor 30 and the second conductor 31 on the flake 24. In the embodiment illustrated, the first conductor 30 and second conductor 31 make contact with transponder 28 via connection between conductive rubber patches 40 and terminals 32. Those skilled in the art will recognize that the first conductor and the second conductor can make contact with the transponder 28 using female couplings on the transponder, where the conductors will "connect" on the transponder. Now with reference to Figure 5, it has been found that damage to the transponder can be minimized during the construction of a tire by orienting the longitudinal direction of the transponder 28b (defined as the site of points including terminals 32 to the transponder), in the same angle or the reinforcing cords 82 in the carcass ply immediately adjacent to the transponder in the tire. It is considered that the efforts found by the transponder in the stages of expansion in the construction of a tire, where the carcass layers pantograph and the distance between them increases in most areas of the tire, are minimized if the transponder "walk over" with one of the reinforcing cords instead of being torn between them. That is, since the longitudinal dimension of the strings does not change in the pantograph action of the strings, if the longitudinal direction of the strings transponder and its terminals are oriented with the longitudinal direction of the reinforcing cords, there is no effort or is minimal in the longitudinal direction of the transponder and the terminals during tire construction. All the effort will be in the directions that the rubber moves with the ropes as the distance between the ropes increases as the shell layer expands. With reference to Figures 6, 7 and 8, the antenna position 26 can comprise any material that provides sufficient conductivity to maintain an electrical circuit under the conditions in which it is employed in a tire. For example, in Figure 6, 40A illustrates an embodiment wherein a wire 44 is wound helically around and around an optionally conductive rubber matrix 42a. Due to the flexibility, and durability of the wire 44, it is not mandatory that the rubber 42a be conductive, but in the illustrated embodiment it is provided as a safety measure in case a separation occurs in the wire 44. In case of this separation, the conductive rubber matrix 42a will provide an alternate path for the electrical circuit created by the interrogator when the tire is interrogated. An electrical conductor is required for the antenna 26, because the conductive rubber is inoperable over the distance that must be traveled by the antenna. In the embodiment wherein the antenna 26 comprises a conductor in a conductive rubber matrix, if the conductor is broken, the resistivity of the conductive rubber is minimized due to the short distance between the two ends of the broken wire, since the resistance depends on the length of the trajectory and the area of the rubber according to the formula: R = pl / A where R is resistance in ohms p is resistivity of the material in ohm-cm. L is the distance traveled in cm. • A is the area of the material surrounding the break. And of course, since the conductor of the antenna 26 is embedded in the conductive rubber, the area (A) will be very large. In an alternate embodiment 40B, as illustrated in Figure 7, at least one wire 46 is provided in a rubber matrix 42b (a conductive rubber matrix in the illustrated embodiment) wherein the wire 46 has a corrugated configuration, which provides the elongation required during the construction of the tire, and the flexibility required when the tire is subjected to deformation when mounted on a vehicle. Although one wire is sufficient to provide the required conductivity, two or more wires can be provided and Use as a backup in case one of the wires breaks. The wires are embedded in a conductive rubber matrix, an electrical circuit can be maintained even if the wires break. Now with reference to Figure 8, 40C represents a mode wherein the antenna portion 26 comprises wire fibers 48 that are embedded in a conductive rubber matrix 42a. In the case where the wire fibers are used, the rubber matrix is required to be conductive since it provides the path for the electric current and is increased by the wire fiber. The wire used for the antenna portion 26 can be filament wire, or rope or braided wire. In an illustrated embodiment, wire similar to the wire used in shell reinforcement is employed and comprises six high tensile steel filaments (HTS = High Tension Steel) wound around a wire core. The wire used in the antenna portion 26 has a diameter of .04 to .25 mm, preferably .08 to .18 mm. In the illustrated embodiment, the wire has a diameter of 0.15 mm. Those with skill in the specialty will recognize that other means can be provided for improve the conductivity of a rubber matrix that is used in a meumático with the purpose of providing an electrical circuit, such as metal filings, metal shavings, powdered metal, etc. In an alternate embodiment, the conductivity of the antenna can be provided by an organic conductor such as polyaniline which is available from AlliedSignal Corporation through Americhem. This material has the product code No. 36721-C1. Those skilled in the art will also recognize that the antenna and transponder of the invention will be operable if associated with a tire in which the data is desired. For example, with reference to Figure 9, a wheel 50 is illustrated in which the tire 52 is mounted on the rim 54. In the illustrated embodiment, a spacing structure 56 having faces 58 is mounted between the rim flange 57 and the tire 52. The transponder 28 can be located in a spacing structure 56. An antenna and other convenient structure as described above can be employed with the transponder 28 in the spacing structure 56. During the construction of a tire, there are three changes of expansion within the structure of the tire that together cause the tire to expand 128% to 133% of its size in the construction drum. The wire construction employed in the illustrated embodiment provides a design expansion of approximately 300%. In general, it is considered that compounds that are sufficiently conductive to provide an electrical circuit in the environment of the tire can be employed in the construction of the tire, if they have a shaping ratio that allows elongation of 100 to 300%. By conformational relationship is meant that the material can be provided in a helical structure bent into a sign form or square shape, bent into a sawtooth wave or other configuration, such that it can expand in length without creating effort in the molecular constitution of the material . The antenna portion 26 can be provided, in the illustrated embodiment, in one to three turns around a tire. Although a sufficient signal can be obtained with one turn of the antenna portion 26, the signal is reinforced as additional turns or additional windings are added since the amount of current developed depends on the number of magnetic flux lines found by the antenna in accordance with the law of Ampere. It has been found that the signal can be read by an interrogator in less than two seconds when the interrogator is within 2.54 cm (1") of the tire, when a turn of the antenna portion 26 is employed, and a signal can be obtained in less than two seconds when the interrogator is within 10.16 cm (5") of the antenna portion 26 when two turns of the antenna portion are employed 26. Three different wires can be used to obtain the three turns of the wire In order to reduce the labor involved in applying three turns of wire, all three turns can be applied simultaneously if means are provided to make the required connections on and off. Under the circuit board it is also possible to provide a turn of wire in three turns In order to obtain three turns of the antenna portion 26 around a tire in a continuous wire filament, insulating means must be provided between the wire and the wire. the flake 24 to avoid short circuiting or antenna shunting When a conductive rubber matrix 42 is employed in the antenna portion 26, it is preferred that u A rubber matrix that has a resistivity of 0.1 to 100 ohm.cm is used. In the illustrated embodiment, the rubber matrix 42 has an electrical resistive in the range of 5 to 50 ohm.cm, and in the specific embodiment has a resistivity of 7 ohm. cm. When rubber is stretched, its resistivity, and the resistivity of 7 ohm.cm for the illustrated mode, it is obtained in the rubber not stretched. When stretched 17%, the resistivity in the conductive rubber in the illustrated embodiment is approximately 10 ohm.cm. The conductive rubber matrix can essentially be syndiotactic polybutadiene rubber, natural rubber, styrene butadiene rubber (SBR), halobutyl rubber or any similar type of rubber composition used in the tire technique and mixtures thereof. Rubber is made conductive by using large amounts of electrically conductive carbon black in its formation. Although normal charges of carbon black in a rubber composition employed in a tire are about 25-45 phr, in the conductive rubber compositions employed herein, carbon black is used at a loading of about 75 to 105 phr, and in the illustrated modality black is used. - Electroconductive carbon, 95 phr. Electrically conductive carbon black of the type employed in the illustrated embodiment is available from Cabot Corporation and is designated ASTM N472. In order that the conductive rubber is incorporated into a tire in such a way that it does not affect the properties of the tire, the rubber must have physical properties that are compatible with its placement in the structure of the tire.tire. The conductive rubber within the invention may have a tensile modulus (at 50% elongation) of 21.09 to 28.12 kg / cm2 (300 to 400 psi), an elongation at break from 270 to 350%, a maximum tensile strength of 126.54 to 147.63 kg / cm2 (1,800 to 2,100 psi), rubber adhesion / brass coated steel wire of approximately 40 to 60 newtons strength (75% rubber coverage) and T90 cure time of 10 to 30 minutes. An example of a non-producing portion of a conductive rubber composition may comprise rubber (NR), 80 to 100 parts by weight per 100 parts by weight of rubber (phr) of conductive carbon black, 10 to 24 phr of silica, at 8 phr of tackifying agents, 0 to 4 phr of antioxidants, 0 to 6 phr of antiozoning agents and 0 to 2 phr of stearic acid. The curing package for the rubber composition may comprise 0 to 2 phr of antioxidant, 5 to 15 phr of ZnO, 0 to 2 phr of accelerators and 0 to 2 phr of MgO and 1 to 5 phr of sulfur. One of the primary uses for the apparatus of the invention is to provide data on tires that are candidates for retreading. Before retreading a tire, it is important to know if a tire is under-inflated or rolled at excessively high temperatures. It is also important to know that the tire has been retreated so many times previously. When a tire is under-inflated, the tire is subjected to flexing that is beyond the normal range, and this flexing can cause fatigue of the reinforcement cords in the carcass ply in the side wall or shoulder area of the tire. If a tire is run at excessive temperatures, which sometimes occur when the tire is under-inflated, high temperatures may tend to age the rubber and / or cause separation of the rubber from the contact portion with the floor of the rubber bands. reinforcement, for example. Even under the best of conditions, fatigue will eventually cause breakage of the reinforcing cords, so that there is a limit to the number of times a tire can or will retread. The chip 4 can be provided with means for collecting pressure and temperature data and for receiving information on the number of times a tire is retreaded, to be retained along with the tire identification data. Tires that are candidates for retreading are usually tested for nails and other foreign objects by passing the tire through a device that has a potential of 40,000 volts, so that if a nail or nail hole is present, the device causes the pass an electric arc through the tire to the nail, since a flake can be considered as a foreign object pneumatic, and the test device can cause an arc to the flake, and a flake is destroyed by this potential or this arc, it is necessary that the apparatus of the invention is isolated from the tire test device described above. Accordingly, the chip portion 24 of the apparatus 28 is generally covered with an epoxy layer 38 which provides sufficient insulation to prevent arcing between the flake and the test apparatus. In addition, a non-conductive rubber 39 is placed on and under the chip 24 and on and under the conductive antenna portion 26 to protect the apparatus from the test device. The epoxy used to isolate the flake in the illustrated embodiment is Dexter / Hysol FP4323. The rubber used to isolate the flake and the conductive compound is a non-conductive rubber similar to that used in lineman's gloves and has a low load, in the range of 0 to 10 phr of non-conductive carbon black. Although it is important that the insulating rubber be thick enough to avoid arcing when the test apparatus is used, it is also important that the insulating rubber does not contribute substantially to the weight and caliper of the tire. Accordingly, the insulation rubber is provided having a caliber of 1.27 to 2.03 mm (50 to 80 mils) preferably 1,524 to 1,778 mm (60 to 70 mils). Although the strength or dielectric strength of the insulating rubber is approximately 400 volts / .0254 mm (thousand), a layer of caliber 1,651 mm (65 mils) of rubber, will prevent arcing because the conductivity of the tire itself is much higher than that of the rubber insulation, and the electrical potential will dissipate in the tire, if holes or foreign objects are present, preferably passing through the insulating rubber. The insulating rubber, as was the case with the conductive rubber, must have properties that are consistent with its use in the tire. The insulating rubber used in the illustrated embodiment has a tensile modulus of 87.17 to 101.23 kg / cm2 (1240 to 1440 psi), an elongation at break of 585 to 785%, a Shore A hardness of 44 to 48%, a modulus of 50% of 4.57 to 5.62 kg / cm2 (65 to 80 psi) a T90 of 7 to 16 minutes and specific gravity (sg) of 1.04 to 1.09. The insulating rubber used in the embodiment illustrated may comprise a non-rubber-producing mixture, 0 to 10% phr of low conductivity black carbon, 0 to 24 phr of silica, 0 to 20 phr of clay, 1 to 16 phr of agents which impart tackiness, 0 to 10 phr of process oils, 0 to 4 phr of antioxidant, 0 to 6 phr of antiozoning agent and 0.1 to 2 phr of stearic acid. The cure package can comprise 0 to 2 phr of antioxidant, 0.5 to 16 phr of ZnO, O to l phr of MgO, 0.5 to 3 phr of Accelerators and 0.2 to 5 phr of sulfur. In the illustrated embodiment, when the tire is manufactured, the inner liner is placed on the construction drum first, and then a non-conductive rubber layer, approximately 2.54 cm (1") wide, is placed around the EP of the tire. A transponder is placed in the non-conductive rubber, taking care not to contact the rubber of the inner lining The antenna, which comprises a conductor in a rubber matrix, is placed around the tire in a loop. conductor on the flake, so that any current passing through the flake should pass around the loop and not be derived on the flake directly from the first conductor 30 to the second conductor 31. Finally, a second layer of non-conductive rubber will place on the antenna and the transponder, 360 degrees around the tire, isolating the apparatus from the band structure, which is subsequently added to the construction drum. ma is built in a way known to those with skill in the specialty. In an alternate embodiment of the invention, the inner lining of the tire can be made conductive and co-extruded with the tire bands, thereby reducing the number of manufacturing steps and the complexity of the tire structure itself. In this mode, the insulating rubber will be used primarily to isolate the flake of other types of rubber in the tire. In the illustrated embodiment, the transponder 28 can be approached by an interrogator, the interrogator is designed to read the return signal from the lacquer 24 ten times, and compare each of the signals to ensure that the signal is read correctly, and only after Reading the same signal 10 times display the information to the operator. Although the reading occurs 10 times before being displayed, the reading is very fast, and the answer only takes one or two seconds. The interrogator transmits to a specific radio frequency and the flake responds by staggering down the signal to transmit half of the frequency of the return scanner. The scanner frequency is heterodyned against the signal frequency producing a difference sideband to reinforce the signal response. The transponder 28 can be provided with a re-adjustable temperature switch. A re-adjustable switch is convenient since the high temperatures in the key car, when the tire heals, turn off the switch, and the switch must be reinitialized before the tire is put into service. The switch is reinitializes wirelessly, applying less than 10 mw of power, or of energy at a specific frequency through a selective filter. In the illustrated embodiment, the pressure detector is not covered by the conductive rubber or insulating rubber in order to maintain the sensitivity of the detector. Those skilled in the art will nevertheless recognize that in applications where only information is required / not applicable, the pressure detector can be adapted to provide a specific signal only if a designated maximum pressure is exceeded, and in this use is not It will require high detector sensitivity, and the detector may be covered. Also, those skilled in the art will recognize that if the sensitivity of the detector is increased, and material covering the detector is allowed to be made, a covered pressure detector may be employed. In an alternate embodiment, the pressure sensor may utilize a rubber composition that varies in conductivity with pressure, as described in U.S. Pat. No. 5,143,967 issued to Chrishnan et al. When the pressure is measured, 144 bits of information are used, and the flake, together with the interrogator, converts analog pressure data to digital data to read in the display and feed the memory in the interrogator. In the illustrated mode, the temperature reading is obtained by counting and providing in the interrogator's memory, the number of output sending cycles from the oscillator, the frequency of which is proportional to the temperature. Alternatively, the temperature can be read by converting a voltage signal to a digital display, when there is a shift in bandwidth voltage with a change in temperature. When this temperature switch is used in the flake, it is designed to change signals, ie from O to binaries for example, when the designated maximum temperature of the tire is exceeded. The switch can not be reinitialized by the vehicle operator, and a change in the binary signal of the switch indicates to a retreading operator that a tire has been under-inflated, at high speeds for a long period of time, or otherwise has been subjected to abuse thermally. In the illustrated embodiment, the pressure detector provides information in real time, that is, the tire pressure at the time of reading by the interrogator. Also, the pressure reading can be compensated by the temperature of the tire by known means for those with skill in the specialty. Those skilled in the art will recognize that there may be minor structural differences from tire to tire in a construction that can affect the reading of a pressure sensor, and that if accurate measurements are required or desired, means may be provided to calibrate the detector in a particular tire. This can be done by obtaining a pressure signal before the tire is mounted on a rim and a second signal when the tire is inflated at a specific pressure, and since linearity of results is expected, pressures below and on the first pressure of inflation can be extrapolated. In an alternate embodiment, an end-use pressure detector may be used when the pressure sensor comprises a diaphragm that breaks when the pressure in the tire exceeds the maximum recommended pressure. It is considered that these detectors will find use in high load tires such as aircraft tires and equipment tires to move earth that normally has high inflation pressures in the range of 7.03 to 21.09 kg / cm2 (100 to 300 psi). In the illustrated embodiment, the pressure detector associated with the chip 24 provides a measure of capacitance that is directly related to the pressure inside the tire. In the pressure detector, a highly adulterated silicon electrode having a thin flexible micromachined diaphragm (etched) at its center, it is placed on an electrically conductive substrate, and the separation distance of the flexible diaphragm from the substrate controls the resulting capacitance. Silicon dioxide is used as an electrical insulator, avoiding short between the substrate and the electrode. The surface area of the oxide coating and its separation distance from the substrate controls the capacitance reading. Accordingly, as the pressure in the tire increases, the separation distance between the substrate and silicon electrodes is decreased, and the capacitance changes, as the capacitance is digitally converted to a pressure reading in kg. / cm2 (pounds per square inch) or other dimensions as required. Polyurethane rubber or silicon rubber can be used to fill the gap on the flexible diaphragm to serve as a means of pressure coupling between the tire component and the diaphragm of the invention. The measurement capacitance is in the Farad peak region (pf) and the interrogator can be pre-programmed to convert peak Farad (pf) measurements to kg / cm2 (pounds per square inch). In the illustrated mode, the detector of The temperature is a bi-metal interlock detector, for example a gold / chromium alloy (Au / Cr) on a silicon substrate (Si). When used to measure the depth of the contact portion with the floor, the interrogator is adjusted to read the current in the antenna portion 26, since the rubber is basically transparent to the developed magnetic and electric fields, the reading depends only on the distance of the coil interrogator. Accordingly, when an interrogator contacts the surface of the contact portion with the floor, a precise distance between the flake and the interrogator can be obtained. In one use of the invention, interrogators can be installed on roads or roads and vehicles with non-heeled tires can be easily identified. The following examples are provided to further illustrate and describe the invention. Example 1 The following composition is the specific conductive rubber employed in the illustrated embodiment of the invention.

The composition for resistivity was tested with the following results. In Table 2, compounds 1 to 4 were achieved using conductive carbon black, and compounds 5 and 6 were made using acetylene black. Compound 1 is a cusp compound that it is sometimes used with the apparatus of the type currently claimed (control) and compound 4 is the compound of Table 1.

Example 2 The following composition of Table 3 is the specific insulating rubber employed in the illustrated embodiment of the invention.

The resistivity and other properties of the insulating rubber composition are illustrated in Table 4.

Example 3 Range of "reading" results from three tires with extended mobility (EMT), a tire for passenger vehicle with size suitable for use in a Corvette, showed that all three tires read well around the entire circumference of the portion of contact with the floor (360 ° reading) from the contact to the maximum distance given in Table 5. The two tires have two antenna windings could also be read 360 ° around the side wall. Antennas were installed between the inner liner and the layer in the first stage band builder. They were located in the center line of the band. Antennae were made from steel wires of flexible-wavy wire (7 filaments) laminated between two layers of conductive rubber. Conclusions: A vastly improved reading range was measured in this set of tires compared to a previous test on this type of tire due to changing antenna placement from the face to the center of the band. The first construction of EMT tires could only be read by touching the reader with the surface contact surface and even that was marginal. The corrugated wire was not affected by stretching and relaxing of the band during removal of the band construction drum, i.e. it specifically did not occur twisted with the corrugated wire because it is very flexible. The results of the reading are established in Table 5.

Example 4 This example illustrates how the tire depth TRD can be obtained using the apparatus of the invention. Test configuration 1.- Current transformer with sensitivity of 1 volt / amp connected to boost the current source of the antenna. 2. - Scout antenna placed on the contact surface with the floor of the center of the tire and spaced with stacked cardboard sheets with an approximate thickness of .0127 cm (.050"). Results: The test shows that the procedure is very sensitive ( 1.91 amps / 2.54cm (1 in)) and somewhat linear over the first section of .635 cm (.25") over the contact portion with the floor. There was some sensitivity to how perpendicular the antenna is relative to the tire (the interrogator must be in the same angular position to repeat). While the invention is specifically illustrated and described, those skilled in the art will recognize that the invention can be modified and practiced in a variety of ways, without departing from the spirit of the invention. The invention is limited only by the following claims.

Claims (41)

1. CLAIMS 1.- An annular device for electronically transmitting and amplifying a wheel or tire or other data, the apparatus is characterized in that it comprises: a transponder including an integrated circuit chip and at least first and second electric conductors coupled to the chip, lasca to externally induced radio frequency excitation, causes the data to be output sequentially from the lasca as a voltage appearing between the first and second conductors; and an antenna, with which the transponder is annular in configuration and which is coaxial with the tire or wheel, the antenna comprises a rubber matrix compound and a third electrical conductor, the third electrical conductor is embedded in a rubber matrix, thus, in the absence of contact of the metal conductor to the metal conductor, the conductive rubber reduces the electrical resistance at least one end of the antenna and a first and second electrical conductors.
2. 2. - The annular apparatus according to claim 1, characterized in that it is substantially circumscribed by non-conductive rubber and located within the toroidal region of the tire or on the radially outer side of the wheel rim.
3. 3. - The annular apparatus in accordance with claim 2, characterized in that the transponder includes a pressure sensor having a sensing surface that responds to force placed to respond to pressure changes within the toroidal region of the tire or the radially outer side of the wheel rim.
4. 4. - The annular apparatus according to claim 2, characterized in that the transponder is embedded in non-conductive materials to avoid electrical conduction with significant derivation between the first and second conductors, different than through the third conductor.
5. 5. Apparatus for electronically measuring and storing tire data, characterized in that it comprises a transponder comprising a flake and first and second conductors placed on each side of the flake, the transponder is adapted to respond to predetermined signals that trigger a response signal to transmit identification data and information, the flake has at least sufficient capacity to measure tire pressure data, tire temperature data and retain identification information for the tire, and an antenna portion comprising a compound consisting of a third conductor in a rubber matrix and has a conformation ratio that allows 100 to 300% of compound elongation, the first, second and third conductors are at least partially embedded in a conductive rubber matrix, the compound contacts the transponder through the conductive rubber matrix.
6. 6. - The apparatus according to claim 5, characterized in that the rubber matrix comprises a conductive rubber having a resistivity of 0.1 to 100 ohm. cm.
7. 7. - The apparatus according to claim 5, characterized in that the rubber matrix comprises a conductive rubber having a resistivity of 5 to 50 ohm. cm.
8. 8. - The apparatus according to claim 5, characterized in that the antenna is formed in a loop around the equatorial plane (EP) in a tire where it is placed.
9. 9. The apparatus according to claim 6, characterized in that the conductive material comprises metal plates.
10. 10. The apparatus according to claim 5, characterized in that the conductive material comprises wire cut into short pieces having a length of 1.5 to 12 mm and a dimension ratio of 10 to 1,000.
11. 11.- The apparatus in accordance with the claim 5, characterized in that the conductive material comprises monofilament wire having a diameter of .04 to .25 mm.
12. 12. - The apparatus according to claim 11, characterized in that the wire is bent in a sinusoidal waveform.
13. 13. - The apparatus according to claim 11, characterized in that the wire has a helical conformation.
14. 14. The apparatus according to claim 11, characterized in that the wire is bent into a square, triangular or wave-shaped sawtooth shape or a mixture thereof.
15. 15. The apparatus according to claim 5, characterized in that the first and second conductors are placed on the electrically conductive rubber in immediate proximity to the antenna without contacting the antenna.
16. 16. The apparatus according to claim 5, characterized in that the conductive rubber has a tension modulus (at 50% elongation) of 21.09 to 28.12 kg / cm2 (300 to 400 psi), an elongation to rupture from 270 at 350%, maximum traction of 126.54 to 147.63 kg / cm2 (1,800 to 2,100 psi), rubber adhesion / brass coated steel wire of approximately 40 to 50 newtons strength (75% rubber coverage) and cure time T90 from 10 to 30 minutes.
17. 17. An antenna for receiving a signal from a transmitter device for electronically activating an electronic circuit and for transmitting data from the electronic circuit to a receiving device, the antenna comprising: a conductive composite material consisting of a conducting metal in a matrix of conductive rubber, the compound has a conformation ratio allowing 100 to 300% elongation of the compound; The conductive rubber has a resistivity of 0.1 to 100 ohm.cm, a modulus of 50% from 21.09 to 28.12 kg / cm2 (300 to 400 psi), an elongation at break from 270 to 350%, and the maximum traction of 126. 54 to 147.63 kg / cm2 (1,800 to 2,100 psi), a brass / steel wire adhesion coated with brass of approximately 40 to 50 newtons strength (75% rubber coverage) and T90 cure time of 10 to 30 minutes.
18. 18. The antenna according to claim 17, characterized in that the rubber matrix has a resistivity of 5 to 50 ohm.cm.
19. 19. The antenna according to claim 17, characterized in that the conductive rubber is formed in a loop.
20. 20. The antenna according to claim 17, characterized in that the metal comprises metal plates.
21. 21. The antenna according to claim 17, characterized in that the metal comprises wire cut between two things that have a length of 1.5 to 12 mm and a proportion of dimensions of 10 to 1,000.
22. 22. The antenna according to claim 21, characterized in that the metal comprises monofilament wire having a diameter of 0.08 to .18 mm.
23. 23. The antenna according to claim 21, characterized in that the wire is bent to a sinusoidal waveform.
24. 24. - The antenna according to claim 22, characterized in that the wire has a helical conformation.
25. 25. The antenna according to claim 22, characterized in that the wire is bent into a triangular waveform.
26. 26. The antenna according to claim 22, characterized in that the wire comprises a portion of 50 to 100% of length of the conductive rubber.
27. 27.- A tire comprising at least two parallel annular faces, shell layers wrapped around the faces, contact portion with the floor arranged on the carcass plies in a crown area of the tire, side walls disposed between the floor contact portion and faces and a detection system disposed between the carcass ply and the inner liner, the detection system comprises an apparatus for transmitting data of the tire comprising: a transponder for responding to predetermined signals that trigger a response signal to transmit data and identification information, and a flake associated with the transponder having at least sufficient capacity to measure pressure data, data of tire temperature and retaining identification information for the tire, an antenna comprising elastic filament wire having a diameter of 0.04 mm to 0.25 mm and a shaping ratio allowing 100 to 300% elongation of the wire associated with the transponder , the wire is embedded in a rubber matrix.
28. 28. The tire according to claim 27, characterized in that the rubber matrix comprises a conductive rubber having a resistivity of .1 to 100 ohm. cm.
29. 29. The tire according to claim 27, characterized in that the rubber matrix comprises a conductive rubber having a resistivity of 5 to 50 ohm. cm.
30. 30. - The tire according to claim 27, characterized in that the antenna is formed of a loop.
31. 31. The tire according to claim 27, characterized in that the metal comprises monofilament wire having a diameter of 0.08 to 0.18 mm.
32. 32. The tire according to claim 31, characterized in that the wire is bent in a sinusoidal waveform.
33. 33. - The tire according to claim 31, characterized in that the wire has a helical conformation.
34. 34.- The tire according to claim 31, characterized in that the wire is bent in a square, sawtooth or triangular waveform, and other designs of compressed length.
35. 35.- The tire according to claim 27, characterized in that the flake is placed in the electric conductor rubber in immediate proximity to the wire without contacting the wire.
36. 36.- The tire according to claim 27, characterized in that the conductive rubber has a 50% modulus of 21.09 to 28.12 kg / cm2 (300 to 400 psi), an elongation to rupture from 270 to 350%, a maximum traction of 126.54 to 147.63 kg / cm2 (1,800 to 2,100 psi), a brass / steel wire adhesion coated with brass of approximately 40 to 50 newtons strength (75% rubber coverage) and T90 curing time of 10 to 30 minutes
37. 37.- A rubber composition having a resistivity of 0.1 to 100 ohm.cm comprising a non-producing portion comprising rubber, 80 to 100 parts by weight per 100 parts by weight of rubber (phr) of conductive carbon black, 10 to 24 phr of silica, 0 to 8 phr of tackifying agents, 0 to 4 phr of antioxidants, 0 to 6 phr of antiozoning agents, and 0 to 2 phr of stearic acid, and a curing package comprising 0 to 2 phr of antioxidant, 5 to 15 phr of ZnO, 0 to 2 phr of accelerators, 0 to 2 phr of MgO and 1 to 5 phr of sulfur.
38. 38.- A rubber composition that has an electrical resistance of 400 to 800 volts per .0254 mm (thousand) comprising a non-rubber producing mixture, 0 to 10 phr of low conductivity black carbon, 0 to 24 phr of silica, 0 to 20 phr of clay, 1 to 16 phr of tackifying agents, 0 to 10 phr of process oils, 0 to 4 phr of antioxidants, 0 to 6 phr of antiozoning agents, and 0 to 2 phr of stearic acid , and a curing package comprising 0 to 2 phr of antioxidant, 0.5 to 16 phr of ZnO, O to phr of MgO, 0.5 to 3 phr of accelerators and 0.2 to 5 phr of sulfur.
39. 39.- A tire comprising at least two parallel annular faces, carcass layers wound around faces, floor contact portion disposed on the carcass layers in a crown area of the tire, sidewalls disposed between the contact portion With the floor and faces, and a detection system disposed radially below the shell layer and the inner liner, the detection system comprises an apparatus for transmitting tire data comprising a transponder to respond to predetermined signals that trigger a signal of response for transmitting data and identifying information, a chip associated with the transponder having at least sufficient capacity to transmit pressure data, tire temperature data and identification information for the tire, an antenna associated with transponder terminals; and the flake is oriented in such a way that the linear direction of the flake and its terminals are in immediate proximity with and oriented with the linear direction of the reinforcing cord of the carcass layer.
40. 40.- The tire according to claim 39, characterized in that the antenna is formed in a loop around EP of the tire.
41. 41.- The tire in accordance with the claim 39, characterized in that the antenna comprises monofilament steel wire wound as a spring having a diameter of 0.04 to .4 mm.