Communications: electrical – Condition responsive indicating system – Specific condition
Reexamination Certificate
2000-10-30
2001-10-23
Hofsass, Jeffery (Department: 2632)
Communications: electrical
Condition responsive indicating system
Specific condition
C340S572200, C340S572300, C340S572400, C340S572700
Reexamination Certificate
active
06307477
ABSTRACT:
CROSS REFERENCE TO RELATED APPLICATIONS
This application relates to U.S. patent application entitled PROCESS AND APPARATUS FOR RESETTING A MICRO-MECHANICAL CONDITION SENSOR Ser. No. 09,699,974 Oct. 30, 2000, having a filing date concurrently herewith.
TECHNICAL FIELD
This invention relates to a process and apparatus for resetting a micro-mechanical condition sensor and more particularly with a process and apparatus for resetting a maximum temperature memory switch.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 5,712,609 ('609) to Mehregany et al., incorporated in its entirety by reference herein, describes a micro-mechanical condition sensor, fabricated on a silicon or bimetallic substrate, that is constructed and arranged for sensing a threshold value. As discussed in the '609 Patent, when an extreme temperature condition occurs and is sensed by a micro-mechanical temperature sensor, the sensor latches, and remains latched to provide a memory of the event available for detection purposes. Due to such characteristics, the micro-mechanical temperature sensing circuit has come to be known in the art as a maximum temperature memory switch (MTMS). For detection purposes, test ports are provided to permit the detection of the latched or unlatched states of the MTMS. The detection circuitry applied to the test ports typically detects an electrical condition of the latch, including a resistance, capacitance, continuity or other electrical condition.
In addition, to the foregoing, it is well-known in the art to combine one or more conventional sensors for measuring various temperatures and pressure conditions, with an integrated circuit (IC) to form a multi-chip module. A typical IC generally includes a suitable complimentary, metal-oxide semiconductor (CMOS) having a read only memory (ROM) circuit and an analog to digital (A/D) converter circuit. The IC is also typically constructed and arranged for converting analog temperature and pressure signals from the sensors to digital data corresponding thereto for storage in the ROM circuit of the CMOS chip.
For recording temperature and pressure conditions within pneumatic tires, the aforesaid multi-chip module has been incorporated into an electronic tire tag. A typical electronic tag includes a suitable radio frequency RF transponder having an antenna electrically connected thereto. In addition, the transponder includes one or more temperature or pressure sensors and an integrated circuit. Further, the integrated circuit has a serial number (SN) stored in the ROM circuit thereof, for identifying the electronic tire tag. Moreover, the integrated circuit includes suitable circuitry that is responsive to energization of the RF transponder from an external RF transceiver circuit, for causing the RF transponder to transmit data corresponding to the SN, followed by data corresponding the then current temperature or pressure conditions of the pneumatic tire.
Such electronic tire tags are conventionally encapsulated in rigid or semi-rigid materials, such as urethanes, epoxies or polystyrene resins, hard rubber compounds and the like. Thereafter, the encapsulated electronic tire tags have been wrapped with a green rubber material and, either incorporated within an uncured rubber tire or within a retread tire for vulcanization therewith to form an integral part of a cured or retreaded pneumatic tire, or separately vulcanized to form a cured rubber patch that may be fixedly attached to the innerliner of a pneumatic tire.
More recently, a MTMS as discussed in the '609 Patent, has been conventionally incorporated into an electronic tire tag. The MTMS provides an indication as to whether or not a predetermined, extreme threshold temperature has been experienced by the pneumatic tire in the course of usage thereof. Typically, the predetermined temperature has been selected to evaluate whether the warranties concerning the pneumatic tire will become void because the tire experiences the predetermined, extreme temperature. In effect, achieving the predetermined temperature can be considered irrefutable evidence of abusive use of the tire, i.e. operating the tire in an overloaded or underpressurized condition. However, the elevated temperatures and pressures achieved in the course of the vulcanization of tires, retreads or patches containing a MTMS have caused the latter switches to latch, indicating that the predetermined temperature has been reached. As a result, the MTMS has to be reset before it is useful for the intended purpose of providing an indication of abusive use of the tire in the course of operation thereof.
BRIEF DESCRIPTION OF THE INVENTION
The present invention includes a process and apparatus for resetting a directly resettable micro-mechanical temperature memory switch (MTMS) having an unlatched state and latched state in an electronic tire tag. The resetting process include the steps of providing the electronic tire tag with a radio frequency RF antenna directly electrically connected to the MTMS for applying thereto an RF signal having a predetermined frequency f
2
; and providing transmitter structure for transmitting to the antenna an RF signal having the predetermined frequency (f
2
). The resetting process according to claim
1
, wherein the predetermined frequency (f
2
) is within an ISM equipment frequency band within the range of from 13.553 to 13.567 megahertz. The resetting process includes the step of causing the transmitter structure to transmit the RF signal for a predetermined time interval within the range of substantially 150 to 300 milliseconds.
According to the invention, the MTMS includes a multi-layered resetting beam having a resistance layer, and the causing step including inducing a current in the resistance layer (
21
e
) for dissipation thereof of a predetermined wattage for a predetermined time interval within the range of from substantially 150 to 300 milliseconds and the predetermined wattage is within the range of from substantially 40 to 100 milliwatts.
Further, according to the invention, the step of providing transmitter structure includes the step of providing an RF signal (
94
) having a predetermined power level within the range of from substantially three and one-half to four and one-half watts.
Preferably, the method includes disposing the tag within a tire and the MTMS is reset to the unlatched state subsequent to the tire reaching a predetermined temperature causing the MTMS to go into the latched state.
According to the invention, the electronic tag includes a directly resettable maximum temperature memory switch (MTMS) having an unlatched state and latched state. The electronic tag includes a radio frequency RF antenna directly electrically connected to the MTMS for providing an RF signal thereto and the RF antenna is tuned to a predetermined frequency (f
2
) and electrically connected across the MTMS. The predetermined frequency (f
2
) is within the range of from 13.553 to 13.567 megahertz. The MTMS includes a multi-layered resetting beam having a resistance layer. The RF antenna is tuned to an ISM equipment frequency for inducement of a current in the resistance layer for dissipation thereby of a predetermined wattage within the range of from substantially 40 to 100 milliwatts for a predetermined time interval within the range of from substantially 150 to 300 milliseconds.
In accordance with the invention, the tag is disposed within a tire whereby the MTMS is actuated when the tire reaches a predetermined temperature.
REFERENCES:
patent: 3706952 (1972-12-01), Alley
patent: 5483827 (1996-01-01), Kulka et al.
patent: 5712609 (1998-01-01), Mehregany et al.
patent: 5883305 (1999-03-01), Jo et al.
Pollack Richard Stephen
Starkey Gene Raymond
Cohn Howard M.
Hofsass Jeffery
Tang Son
The Goodyear Tire & Rubber Company
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