WO1997000785A1

WO1997000785A1 - Miniature combination valve and pressure transducer and system

Info

Publication number: WO1997000785A1
Application number: PCT/US1996/010621
Authority: WO
Inventors: Ronald D. Widner
Original assignee: Widner Ronald D
Priority date: 1995-06-23
Filing date: 1996-06-20
Publication date: 1997-01-09
Also published as: US5853020A; US6199575B1

Abstract

A valve/transducer and system for pressure measuring: which has a valve/transducer (24) comprised of an appropriately dimensioned tapered barrel (30) of rigid material with a gasket (40) near the barrel's larger diameter proximal end. The valve/transducer has an opening closable by valve cup (32) which is operated by a pin (34) extending from the barrel. The valve/transducer has within the barrel an integrated silicon circuit (44) and flex circuit electrical interface (76). The integrated circuit provides a pressure transducer (58) and an integrated processor/encoder (68). The system includes wireless transmitter/receiver paired circuits consisting of a transponder (26) and a transmit/receive channel circuit (164). The system includes a control/display processor (162) and an indicator (182) with novel displays of useful tire inflation and maintenance parameters.

Description

Miniature Combination Valve and Pressure Transducer and System

Background - Field of Invention

This invention is related to pressure measuring and signaling and, in particular, a immature valve combined with a pressure transducer.

Background - Prior Art

In practice an acceptable or unacceptable condition of vehicular tire inflation is determined by measiuing tire interior pressure and evaluating whether measured pressure lies . _t an acceptable pressure range which varies with temperature and load. Because such measurements have been difficult to perform on an operating vehicle's tires, alternative methods involving complex systems to measure wheel rotation rate differences have been tried. However, direct pressure measurement and evaluation is the preferred method. There are numerous prior inventions to provide a tire mounted device which generates a pressure indicating signal. All known prior inventions suffer from one or several of four technical flaws which prevent their widespread uti ty. Either the prior inventions are (1) arguably impractical for use, and/or (2) they do not have sufficient accuracy

RECTIFIED SHEET (RULE 91)

ISA/EP and precision to reliably perform the pressure indicating function, and/or (3) they leak air from the tire, and/or (4) they require special modifications ofthe tire or wheel for attachment (therefore, are not easily retrofittable). Additionally, all prior art devices lack sigmficant commercial potential when compared with the present invention.

Technical Deficiencies of Prior Art

Impractical Function

My first objection to the prior art is that device functions are complex and impractical. For example, Patent 4819686 issued to Achterholt on April 11, 1989 and other prior art devices have a reference chamber which inflates upon attachment ofthe signaling device to an inflated tire. Afterward combinations of springs, diaphragms, bellows, and/or electrical or mechanical indicating components momtor the drop in pressure between the reference chamber and the interior ofthe tire. Upon detecting sufficient pressure drop, they issue an under inflation alarm. I question the reliable and economic realization of such devices. I believe it very difficult for inexpensive devices to inflate the reference chamber to a proper pressure, to seal and maintain the reference pressure at an accurate level, and to preserve the interior tire pressure during the initial attachment ofthe device and thereafter during the tire's operation.

Insufficient Accuracy

A second objection is in regard to measuring accuracy of prior art devices. Complex devices (such as patent 4737760 to Huang and Kuo on April 12, 1988 and including the type previously described) implemented with mechanically manufactured springs, diaphragms, bellows, balloons, and the like indicating components are typically imprecise when manufactured cheaply. Further complicating implementation is the requirement that the indication must compensate for the known temperature dependency of pressure to produce suitable results. I question whether the majority of prior art devices can achieve the required accuracy and temperature compensation. Finally, accurate inflation assessment should account for vehicular weight and loading variations. Present devices which indicate under inflation fail to do this.

RECTIFIED SHEET (RULE 91) ISA/EP Prone to Leak

I also find unsuitable the typical arrangements for installation of existing devices. Either they will be. retrofittable onto tire stems by end users or require unretrofittable (by end users) modifications. For the former case, the method of installation makes the device prone to leak. In the latter case see the following titled paragraph. The two previous devices (Achterholt and Huang/Kuo) and patent 5040562 to Achterholt on Aug 20, 1991 , open the tire's existing valve to admit the interior tire pressure to the indicating device when they are attached to the tire. This valve opening overrides the proven sealing method ofthe valve core and stem. The alternative pressure sealing provided within the indicating cap are inferior sealing methods. My argument for this requires a review ofthe valve core and stem sealing and then a comparison ofthe inferior replacement sealing.

The pressure seal of a normal tire inflation valve is in two parts. The first part is a moveable cup and elastic seal which opens for admitting or releasing air from the tire. When closed, the elastic seal is compressed between the cup and the end ofthe valve core by a spring force.

The tire interior pressure also acts on the cup with closing forces rather than opening forces. The seal has a comparatively large ratio of its radial thickness to its circumference. This ensures that potential air leaking channels which might develop radially outward between the tire stem and seal become closed prior to their reaching the opposite lower-pressure side of the seal ring. The second sealing part is a relatively wide elastic band or gasket pressed against a precision interior surface ofthe stem. This surface's sole function is as a seat for sealing the valve core gasket. Its condition is protected from damage by its interior position in the tire stem. The tire valve is constructed so that during installation sealing surfaces mate to one another without their relative rotation. This construction has proven to be very reliable in commercial practice for mamtaining interior tire pressure.

In contrast, the seal objected to in prior art inventions is (usually) an elastic seal which compresses between the exterior ofthe tire inflation stem and the indicating device. This seal is less reliable than the conventional tire valve for the following reasons. First consider the tire inflation stem end surface, whose normal function is as a temporary seat for inflating chucks and for attaching of a non-pressure sealing dust cover. This surface can easily become burred or nicked from a number of causes without affecting its normal function. A principle

RECTIFIED SHEET (RULE 91) ISA/EP cause of damage is likely to be the very air chucks used in inflation. Secondly, the screw threads are fine pitch which require the sealing elastic to rotate many revolutions against the stem end during installation ofthe indicating device. This rotation may shear the elastic as it contacts the tire inflation stem - thus, potentially degrading the elastic seal.

During maintenance inflations ofthe tire, the indicating device will be removed and reinstalled, additionally shearing the elastic seal. If the elastic seal takes a set (non-elastic deformation, creep, etc.) during use, the proper action is to discard the removed device and replace it with a new device. Re-use of an old device in this case could result in sigmficant leaking resulting from re-orientation of set material with respect to stem non-uniformities.

Finally, in the objectionable devices, tire interior pressure exerts an opening force on the seal.

Requires Modification of Other Vehicle Products for Use

A fourth objection to the prior art is their means of being installed onto the tire. In, for example, patent 5040561 issued to Achterholt on Aug 20, 1991 and patent 4177671 to

Ichihara et al. on Dec 11 , 1979 and other known prior art, a tire must be removed from its wheel in order to install a modified stem type tire gauging device. In other cases, patent 4562874 issued to Scheller on Jan 7, 1986, for example, the wheel is modified to accept the gauge installation. Patent 5218861 issued to Brown et al. on Mar 27, 1991 is for a tire with a pressure sensor and transducer embedded under the tread.

Prior Art Lacks Broad Market Potential

The design of all known prior art devices limits commercial market size. Each known device would require a substantially different product design for apphcation on, for example, a bicycle tire versus heavy trucking or airplane tires. Many ofthe prior art devices are impractical to use in small tire applications due to their considerable size and weight compared to the dimensions of a bicycle tire. For prior art designs that could be adapted to the full range of pneumatic tire applications, it is not commercially feasible to do so. For all except valve cap devices wliich are prone to leak, this is particularly true because the product requires not only different products for specific apphcation but also different tire, tubes, or

RECTIFIED SHEET (RULE 91) ISA EP wheels than current products for sale. Therefore, commercialization of prior art devices is relegated to minor market niches.

Summary of Prior Art Deficiencies

The above describes relevant prior art and classifies the deficiencies with each as examples of the number of unsuccessful attempts to solve the current problem. Significant commercialization and profitability of tire inflation alarming devices will require better technical performance and general apphcation to broadest range of pneumatic tire use than possible with prior art. In all cases the approach ofthe prior art has taught away from the approach of my present invention. My invention will be shown to have overcome the significant techmcal problems and to meet the commercialization goal.

Objects and Advantages of Miniature Combined Valve/Transducer Invention

Accordingly, several objects and advantages of my invention are high precision in gauging tire pressure and alarming under inflation, reUable operation and reliable sealing of tire pressure. My miniature valve/pressure transducer invention has advantages in commercialization. It provides easily performed retrofit ofthe valve/transducer invention to the full range of existing vehicular tires, as well as retrofit into numerous non-tire apphcations. My valve/transducer features low cost of manufacture consistent with wide market potential.

There is a broad scope of new apphcations for combined valve and pressure signaling in retrofit markets. I also beheve my valve/transducer invention will enable creation of new markets and design apphcations using smaller pressure transducers resulting from the miniature form-factor of my approach. Apphcations other than these are possible. With regard to tire pressure gauging, the primary apphcation for my valve core/transducer invention, I anticipate that manufacture of a few pressure range variants will be sufficient to cover use on the broad class of pneumatic tires for trucking (light, medium, and heavy), commercial transportation from passenger cars, taxi's, buses, etc. through airplane, and private

RECTIFIED SHEET (RULE 91) ISA/EP transportation including bicycles, scooters, motorcycles, and autos. Further objects and advantages of my invention will become apparent from consideration ofthe drawings and ensuing description.

Description of Drawing Figures

Figure 1 is a perspective view of several vehicles with pneumatic tires indicating general locations of tire and non-tire air valves.

Figure 2 shows prior art. It provides cross sections of a typical prior art non-gauging valve core within a stem and a prior art modification to the valve stem.

Figure 3 is exploded view of installation ofthe preferred embodiment of my invention in the reference stem of figure 2.

Figure 4 is cross section view of my invention's pressure signaling valve core device.

Figure 5 is a drawing of three views (top, side, and bottom) of my invention's pressure signal processing integrated circuit.

Figure 6 is a cross section view of my invention's wireless commumcation device.

Figure 7 is a cross section view of my invention's energizing device and valve stem cap.

Figure 8 is a block diagram of my invention's electronic circuits.

Figure 9 is a perspective view of one means of operating the apparatus of my invention.

Figure 10 is a drawing indicating alternative embodiments of my invention. Several are shown, but they should not be considered comprehensive.

RECTIFIED SHEET (RULE 91) ISA/EP Reference Numerals on Drawmgs

20 Inflating Stem (Reference) 22 Valve Core (prior art)

24 Pressure Signaling Valve Core 26 RF Transponder & Ste Extender

28 Stem Cap with Battery 30 Valve Core Barrel

32 Valve Closure Cup 34 Valve Activating Pin

36 Valve Cup Seal 38 Valve Closure Spring

40 Valve Barrel Seat Seal 42 Exterior Thread Valve Seating Nut

44 Pressure Signal Processor Integrated Circuit 46 Barrel Indentation Exterior Mounting Seat

48 Barrel Interior Mounting Seat 50 IC Exterior Seal Area

52 IC Interior Seal & Mounting Area 54 IC Annular Seal Area

56 IC Mounting & Sealing Adhesive 58 Integrated Pressure Transducer

60 Transducer Diaphragm 62 Pressure Responding Pfezo-Resistors

64 Piezo-Resistor Bridge Circuit 66 Analog Conditioning and Interface Circuit

68 Integrated Signal Processor Encoder 70 Integrated EEPROM

72 integrated Pressure Micro-Switch 74 IC Interconnect Bond Area

76 Interconnecting Flex Circuit 78 Actuating Pin Guide

80 Actuating Pin Clearance Groove 82 Inner Flex Retainer

84 Outer Flex Retainer 86 Snap-Lock Connector Mating Half

88 Flex Retainer Clip 90 Transponder Housing

92 Transponder Extension Barrel 94 Snap-Lock Connector Mating Half

96 Printed Circuit Assembly 98 RF Transponder Antenna Assembly

100 RF Transmitter Receiver Assembly 102 RF Wake-up Circuit

104 Battery Connector 106 Stem Extension Seal O-Ring

108 Stem Extension Exterior Thread 110

112 Stem Cap Housing 114 Cap Seal O-Ring

116 Battery 118 Piezo-Electric Buzzer Alarm

120 Hand-Held Remote Processor/Display Assy.. 122 Differential Amplifier

124 Delta-Sigma Analog/Digital Converter 126 Bridge Bias Circuit

128 Temperature Compensation Circuit 130 Inflation Model & Limit Processor

132 Sync Decoder/Signal Encoder Circuit 134 RF Oscillator

136 Transmit Data Modulator 138 RF Amplifier/Transmitter Circuit

140 F Antenna 142 Receive/Transmit Antenna Multiplexer

144 Receiver Amp/ Demodulator Circuit 146 Receive/Transmit Gate Circuit

148 Tuned Filter Rectifier Wake-up Circuit 150 Wa e-up/Sleep Power Switch

152 Piezo-Buzzer/Flasher Alarm Driver 154 Cap/Transponder Connector

RECTIFIED SHEET (RULE 91) 156 Solar-Electric Battery Recharger 158

160 Vehicle Installed Chassis Subsystem 162 Control and Display Microprocessor

164 Transmit Receive Interface Channel 166 Wheel Well Mounted Printed Anteπna(s)

168 RF Oscittator 170 Transmit Data Modulator Circuit

172 RF Amplifier 174 Receive Transmit Gate Timing Circuit

176 Transmit RF Blocking Circuit 178 Receiver Gain & Demodulator

180 Shift Register/Channel Code Generator 182 System Display Unit

184 System Controls 186 Vehicle Integration Input Output Circuit

188 Multi-Tire Load Evaluation Algorithm 190 Tire Parameter & Pressure History Memory

192 Tire Accumulated Miles Calculation 194 Condition Display Selection Logic

196 Fiber Optic Pressure Signaling Device 198 Optically Resonated Pressure/Temp Sensor

200 Fiber Optic Flex Interface 202 Valve Cup Mounted Pressure Sensor

204 Micro-machined Pressure Die 206 Hollow-Pin Valve Actuator

208 Interface Wiring 210 Protective Cover

212 Silicon Gel Encapsulation 214 Surface Acoustic Wave Transponder

216 SAW Receiver/Antenna Assembly 218 Pressure Sensitive Switch

220 Flex Wrap Assembly 222 Anti-Rotation Shearable Adhesive Bead

224 Two-part Weldable Barrel Assembly 226 Pressure Die Mounting Pedestal

228 Pressure Sampling Hole 230 Barrel Top Assembly

232 Ceramic Feed-Thru Circuit 234 Flex Circuit Assy.

236 238

240 MEMS Gyro Structure 242

Summary of invention

Briefly my invention is comprised of a valve/transducer and system for pressure measuring. In it the valve/transducer is an appropriately dimensioned tapered barrel of rigid material with a gasket near the barrel's larger diameter and with a closable valve opening . My invention uses a pressure transducer combined with an integrated processor and interface. This combined transducer and processor is an integrated silicon circuit contained within the tapered banel. My invention further includes wireless transmitter/receiver paired circuits and an indicator with novel displays of useful tire inflation and maintenance parameters.

RECTIFIED SHEET (RULE 91) ISA/EP Structural Description of the Invention

Figure l

The figure shows a range of vehicles and indicates general locations on vehicles for applying my invention, a lniniature combined valve and pressure signal generator or pressure signaling valve core 24 and an apparatus or system for use. Valve core 24 installs in vehicle pneumatic tires, shock absorbing coπφonents, and refrigeration coπφonents as indicated in figure 1. A system for use consists of several component parts, namely an RF transponder or wireless communicating device 26, a stem cap with battery or energy source 28, (each used in multiples accordmg to number of valve cores 24 used) and a vehicle installed apparatus or chassis subsystem 160. An alternate form for a system consists of a hand-held interrogator or remote processor/display assembly 120 (not shown in figure 1) and the remaining components used in multiples; transponder 26, cap 28, and valve core 24. The vehicles to which my invention applies include private, commercial, and mihtary for pneumatic tires. There are non- tire related apphcations on the same vehicles.

Figure 2

This figure shows prior art. The several valve arrangements shown constrain the form, fit, and function of my mvention. With respect to the apphcation there is an inflating stem or pressure introducing tube 20 which will be used in reference in following figures describing the configuration of my invention. Installed in stem 20 is a prior-art valve core 22 and covered with a prior-art stem cap not shown. Retrofit of my invention is simply accomphshed by removing prior art stem caps and prior art valve cores 22 and replacing them with valve cores 24, transponders 26, and caps 28 shown in detail in figure 3. It helps to understand the nature of my invention by noting the similarity of form of prior art valve cores 22, 22', 22' , and 22'" independent ofthe specifics of their apphcation. In contrast, note the variability of the external form of reference stems 20, 20', 20", and 20"' depending on the specifics of their apphcation.

RECTIFIED SHEET (RULE 91) ISA/EP Figures 3 through 5

Figure 3's exploded view shows the relationship between valve core 24, transponder 26, and cap 28 in relation to each other and reference stem 20. When installed in stem 20, valve core 24 is positioned such that gasket 40 compresses against an interior smooth bore drilling of stem 20 by an engagement of exterior threads of nut 42 with an interior thread of stem 20. transponder 26 installs to an outside threaded surface of stem 20 and electrically connects to core 24 as shown in figure 6. cap 28 installs over transponder 26 employing the features shown in figures 6 and 7 for their physical and electrical interconnection. In the following descriptions, I use the following terms and definitions to orient and clarify descriptions:

proximal and distal ends of items, points or locations; in this context the reference viewpoint will be from an outside of cap 28 (at left in figure 3) along a central axis of stem 20's drilled interior toward its right hand side on figure 3. Proximal is relatively nearer cap 28 and distal is relatively farther from cap 28, and

inside or interior and outside or exterior of hollowed components; in this context the inside/outside reference will be to the item itself- hence, it is possible for the outside surface of a part to face or contact the inside surface of another part.

Visible in figure 3 are the following components of valve core 24: a valve core barrel 30, a valve closure cup 32, a valve activating pin or push rod 34, a valve barrel seat seal or gasket 40, an exterior threaded valve seating nut or exterior threaded ring 42, a distal end of a pressure signal processor integrated circuit, IC dice, pressure probe, or micro-machined pressure chip 44, a barrel indentation exterior mounting seat or pressure probe seal depression 46, a proximal end of a flex circuit or electrical interconnecting assembly 76, and a flex connector or one-half of a mating pair snap lock connector 86. These components are shown in figure 4 in cross section and IC 44 is also shown in figure 5's plan views.

Figure 4 shows a physical connection (typically metal crimping) of pin 34 into cup 32 also containing a valve cup seal, o-ring, or gasket 36. Seal 36 is compressed against a distal end surface of barrel 30 by a valve closure spring or coil spring 38. A distal end of spring 38 bears

RECTIFIED SHEET (RULE 91) ISA/EP against an inside distal surface of barrel 30. An opposite or proximal end of spring 38 is attached to pin 34 near an approximate midpoint of pin 34.

Also referring to figure 4, IC 44 mounts on a flattened inside surface, formed mounting seat, or mounting floor 48 in barrel 30 attaching by means of an adhesive, epoxy, eutectic bond, or mounting and sealing compound 56 in adhesion with mounting floor 48 and a proximal bottom-side area or seal/mount planar surface 52 of IC 44. IC 44 further extends in a distal direction projecting through a hole onto indentation 46 where it is attached by adhesive 56 between indentation 46 and a top-side planar surface or seal area of IC 44. Adhesive 56 also fills an annular gap between barrel 30 and IC 44 adhering to both barrel 30 and an annular seal area of IC 44. When assembled as described, IC 44, adhesive 56, barrel 30, cup 32, seal 36, gasket 40, and a previously mentioned inside surface of stem 20 form a continuous sohd barrier - leak resistant to an operational high pressure difference between barrel 30 inside and barrel 30 outside surfaces distal to gasket 40.

IC 44 contams an integrated nήcro-machined pressure transducer 58 consisting of a flexible diaphragm 60 combined with a pressure reference cavity 60'. A set of four piezo-resistors 62 are constructed during IC 44 fabrication within areas of flexure strain on transducer diaphragm 60. Piezo-resistors 62 are interconnected to form a sensitive bridge circuit 64 which provides an electrical signal approximately proportionally responsive to a difference in pressure apphed to diaphragm 60 outside surface with respect to cavity 60'. IC 44 further contains integrated analog circuits 66 and digital electromc circuits or processor/encoder circuits 68 electrically connected to piezo-resistors 62. IC 44 further contains an integrated digital memory circuit or EEPROM 70, and an integrated encoder processor circuit/encoder 68. Piezo-resistors 62, analog interface 66, processor/encoder 68, EEPROM 70 are constructed and interconnected during IC 44 fabrication. Their interconnection and functional purpose is as shown in figure 8 electromc block diagram. Processor/encoder 68 connects to an arrangement of electrical signal bonding pads or IC interconnecting pads or flip-chip interconnects or Ball-Grid- Array (BGA) solder bumps 74. BGA bond pads 74 assembles and electrically connects to a distal end of flex circuit 76 which has a mating pattern of electrical conductors.

RECTIFIED SHEET (RULE 91) ISA/EP Flex circuit 76, providing electrical mterface between IC 44 and ren_aining components of a system, exits a proximal end opening in barrel 30. Hex circuit 76 attaches to an actuating pin guide or plastic supporting spline 78 and coils around guide 78 and proximally exits core 24 though a center opening in nut 42. Guide 78 has an axial hole of non-circular cross section and matching a non-circular (possibly square) cross section of pin 34 which passes through guide 78. At a distal end of guide 78, it has exterior splines of shape and size matching barrel 30's proximal opening. Exterior splines of guide 78 taper to a smaller diameter near a proximal end of guide 78 where guide 78 enters a hole in an inner flex retainer 82. A coil wrapping of flex circuit 76, supported by guide 78 on an inner radius and supported by an outer flex retamer 84 on an outer radius is contained within a cylindrical box formed by guide

78, retainer 82, and retainer 84. Retainer 82 with attached flex circuit 76 is free to rotate approximately one turn clockwise and one turn counter-clockwise with respect to guide 78 thereby forming a twist capsule or rotationally coupled electrical interconnecting assembly with flex circuit 76.

Final structural description of core 24 identifies that pin 34 is patterned with a series of bends in a plane beginning on a distal side of guide 78. Bends in pin 34 allow pin 34 and spring 38 to clear an inner surface of barrel 30 and IC 44. As necessary IC 44 will contain a pin clearance groove 80 proximally located on its top surface. IC 44 will also contain a microstructure pressure switch 72, normally open with pressure above a first predetermined pressure value. Switch 72 closes with pressure below a second predetermined pressure value.

Nut 42 is positioned over barrel 30 during assembly of flex circuit 76 and retainers 82 and 84 and retained by rolling a distal edge of nut 42 into a circumferential groove in barrel 30. Retainers 82 and 84 have spoked wheel appearance wliich are primarily open to allow air to pass through them. All parts described are capable of very economical mass production using, for example; metal stamping or forging for barrel 30, cup 32, pin 34, and nut 42; plastic injection molding for guide 78, and retainers 82 and 84; printed circuit fabrication for flex circuit 76; anisotropic etching of bulk silicon and anodic bonding of multiple wafers for constructing the form of IC 44, transducer 58, reference cavity 60', micro-switch 72, and/or pressure ducting channels interior to IC 44 as required; conventional integrated circuit fabrication (for example CMOS fabrication processes) for epitaxial growth, patterning,

RECTIFIED SHEET (RULE 91) etching, diffusing, oxidizing, and metahzing to construct integrated circuit elements for analog interface 66, processor/encoder 68, EEPROM 70, and bond pads 74. Electrical assembly is simple requiring BGA attachment of flex circuit 76 to IC 44 prior to installation ofthe assembly into barrel 30. Wire bonding at the level of assembly of core 24 or barrel 30 with IC 44, wliich would require non-traditional manufacturing equipment/process, is avoided in this embodiment of my invention. Other manufacturing procedures are possible for the fabrication of core 24 and/or its component parts.

The dimensions of core 24 are approximately 35 mm in length from end of cup 32 to end of pin 34 and 5.5 mm diameter at gasket 40 tapering to 3 mm at the smallest diameter of barrel 30. IC 44 measures approximately 12 mm in length by 2.5 mm in width by 2 mm in height. Flex circuit 76 has 4 printed conductors each approximately equivalent to 40 AWG wire and measures less than 0.2 mm in thickness, 1.2 mm in width, and total equivalent length of approximately 38 mm. Transducer 58 diaphragm and piezo-resistors 62, in combination, are less than 1mm square. Area for integration of analog circuit 66, processor/encoder 68, and EEPROM 70 is approximately 4mm by 2mm. Transponder 26 is approximately 17.5 mmin diameter by 13.5 mm in length. Cap 28 is approximately 19 mm in diameter by 8 to 16 mm in length.

Figures 3. 6. and 7

Figure 3 shows RF transponder 26 which has a transmitter/receiver assembly, RF circuit assembly, or printed wiring assembly 96 shown in cross section in figure 6. Circuit 96 is connected to a miniature RF antenna, printed antenna, or high frequency coil 98 and to a second mating connector half 94 of a connector mating pair. Circuit 96, antenna 98 and connector 94 fit within a stem extender housing, transponder external housing or tubular electronic case 90. Interior to housing 90, circuit 96, and antenna 98 is a second tubular barrel 92 which is threaded on its interior at a distal end with threads mating with proximal exterior threads of stem 20. An O-ring or moisture seal 106 fits within an internal annular interface of banel 92 such that when transponder 26 is installed upon stem 20, O-ring 106 seals the assembly of 20 and transponder 26 from moisture penetration through their mated threaded interface. Interior threads of transponder 26 will have integral torque locking provisions or be used with thread locking adhesive to prevent accidental back off from torques apphed to cap 28.

When transponder 26 is tightly mated to stem 20, the extended length provided by barrel 92 matches a proximal extension of pin 34 such that the relative positioning of a button formed on pin 34's proximal end with respect to barrel 92's proximal opening matches the relative positioning of a similar pin of prior art valve core 22 with respect to stem 20's proximal opening. An exposed proximal end of barrel 92 has an exterior and interior diameter and exterior threads matching stem 20's diameters and threads. Distal to barrel 92's exterior threaded extension, barrel 92 is penetrated by a hole through which connector 94 connects with circuit 96. connector 94 attaches to an inside arc segment of barrel 92. After transponder 26 is threaded onto stem 20, connectors 86 and connector 94 are mated electricaUy and retained in mating position by a snap-fit retention design of their mating interfaces.

Figure 3 shows cap 28 in relative position to transponder 26. Figure 7, cross section, shows cap 28 as a double wall closed cap with an interior thread, cap 28's interior thread matches exterior threads of transponder 26. Between case walls of cap 28 there is a battery 116 and a quartz vibrator disc or piezo-electric buzzer 118. Near an outer circumference of a distal disc surface of cap 28 is an O-ring 114. O-ring 114 seals the assembly of cap 28 and transponder

26 from moisture intrusion at the interface plane between transponder 26 and cap 28. An electrical interconnection between transponder 26 and cap 28 is provided by electrical conductor circuit traces and wiping contacts on the mating surfaces of transponder 26 and cap 28 inside O-ring 114's circumference. Electrical contacts are not shown but each contact pair can be similar in form to a printed variable resistor and center tapping slide.

Description of System Components

A hand held remote RF transmitter/receiver 120, as shown in figure 9, is one embodiment of a device for interrogating and displaying the pressure indicating signals and other data produced by core 24 assembled with transponder 26 and cap 28. For most vehicular apphcations however, a system of components mounted on the vehicle is prefeπed. An apparatus or

RECTIFIED SHEET (RULE 91) chassis subsystem 160, as indicated in figure 1, consists of a set of printed circuit antennae 166 mounted in a vehicle wheel well near the tire(s) with attached core 24. Each antenna 166 is connected to an RF channel circuit module 164. The size, shape, and weight of channel modules 164 and antenna(e) 166 are not of significance as long as the equipment functions in accordance with requirements identified in figure 8, electronic block diagram. A plurahty of antennae 166 and channel modules 164 are interconnected via a conventional interconnect wiring assembly or electrical cable, not shown, to an electronic assembly with control/display 162 mounted in the vehicle in a position viewable and operable by the vehicle driver. Physical configuration of module 164 is of little importance except that it be esthetically pleasing and ergonomically suitable to its purpose as detailed in figure 8. Control/display

162, module(s) 164, and antenna(e) 166 together are chassis subsystem 160. They are manufacturable using conventional or high density electronic assembly design and construction methods, such as printed wiring boards, hybrid or multi-chip-module, apphcation specific integrated circuits, field programmable gate arrays, discrete electronic componentry, hquid crystal display, LED display devices, and wired cable assembhes and combinations of these methods and others not mentioned.

Block Diagram

Figure 8 shows the electronic elements of my valve/transponder invention and system. It presents a lower level of functional detail than described in the earher mechanically oriented paragraphs. The functional relationships and features ofthe electronic elements identifies novel signal processing features of my invention. These enable a wide range of potentially useful displays and indica from the system. The operational description paragraphs present some ofthe potential output indica. However, many more are possible with the electronic functions (and their natural extensions) shown in the foUowing paragraphs.

A set of signals consisting of electrical power, control signals, and data signals (one such data signal being a conditioned pressure signal) provide interface between IC 44 and remaining components ofthe system. As previously shown, IC 44 consists of transducer 58, analog interface 66, processor/encoder 68, EEPROM 70, and interconnecting circuitry. Figure 8a provides additional functional details of these elements. Transducer 58 consists of diaphragm

RECTIFIED SHEET (RULE 91) ISA/EP 60, piezo-resistors 62 connected in a five-teπninal bridge circuit 64 as shown. Bridge 64 connects to both a current source bias circuit 126 (which is operated in two bias states) and to a differential amplifier 122. Bias circuit 126 and amplifier 122 are part of analog interface 66 as is an over-sampled delta-sigma analog/digital converter (ADC) 124. Serial digital signals from ADC 124 connects to a linearizing and temperature compensating processor or calibrator 128. Calibrator 128 controls the bias mode of bias circuit 126. According to which ofthe two bias states is selected, ADC 124's output wiU represent either a first digital signal or a second digital signal. The first digital signal wiU be more sensitive to strain produced variation of piezo-resistance in bridge 64 than in temperature induced variation. Conversely, the second digital signal wiU be more sensitive to temperature than to strain. From the first and second digital signals, calibrator 128 produces compensated pressure and temperature digital data using a set of mathematical model coefficients from EEPROM 70.

Note: PhysicaUy, calibrator 128 can be realized by means of a conventional arithmetic logic unit (ALU), a conventional digital state controUer, and a control program.

Together these items comprise IC 44's processor/encoder 68. 1 have chosen to use a functional rather than a physical description of IC 44's processor/encoder 68. I believe the functional description is the better explanation of my invention. Inflation/alarm processing and data encoding wiU also be performed as sequential operations by the physical logic used by calibrator 128.

Processor/encoder 68 operates on conφensated pressure and temperature data via an inflation model processor to determine a binary value (true or false) for a tire inflation condition alarm. The inflation/alarm processor provides model outputs to a data encoding process which serializes model output data for transmission to remote units 120 or chassis subsystem 160.

Flex circuit 76 and connectors 86 and 94, shown combined as a single block, provide electrical interconnection to RF transponder 26. Serial output data encoding is Manchester or bi-phase encoding which is self clocking. Serial data flow is bi-directional on a conductor pair in flex circuit 76. Processor/encoder 68 outputs encoded data only within a predefined gate (time window) synchronized with a timing protocol synchronized to signals transfened from transponder 26 circuits.

RECTIFIED SHEET (RULE 91) P Micromachined micro-switch 68's output wire-or connects with inflation/alarm processor 128's binary signal. This signal interconnects to an alarm circuit (piezo-buzzer of LED flasher) 152 in cap 28 through a conductor in flex circuit 76.

RF transponder 26 consists of RF transmission and receiving circuits as shown. The circuits required for transmission of encoded transducer outputs of valve core 24 include an RF local osciUator 134, a modulator circuit 136, an RF "power" amplifier 138, and an antenna 140. Circuits required for reception include an RF power blocking circuit 146 and a receiver/demodulator circuit 144. RF block 146 prevents "high power" transmit signals from being introduced into receiver/demodulator 144. It is realizable as a pin diode switch (i.e., for use with transmit/receive using single frequency band) or as a band-pass filter (i.e., duplex type interface using separate frequency bands for transmit/receive). A received and demodulated synclironizing pulse or code word drives a receiver/transmitter gate timing generator circuit 146. Gate circuit 146 controls the Manchester interface timing protocol and enables RF amphfier 138 and RF block (switch) 146. RF Frequencies used by the transponder are the unlicensed RF bands.

Other control circuitry relates to a power reducing sleep mode of operation. A low r^ FET transistor switch 150 normaUy disconnects battery 156 from transponder 26 and valve core 24 circuits. This is a low battery drain sleep mode. An RF detector circuit detects in-band RF energy from antenna 140 when a remote unit (either hand-held unit 120 or from chassis subsystem 160) operates. A detected wake signal or binary discrete from detector 148 wakes up transponder 26 and valve core 24 circuits by switching transistor 150 ON. Thus, battery 156 is not drained when no remote unit 120 or chassis subsystem 160 is operating (i.e., the vehicle is not operating and is unattended).

Chassis Subsystem - Figure 8B

Figure 8B shows the components and electronic functions of chassis subsystem 160. The RF circuitry comprising a transmit/receive channel 164 is similar in function to transponder 26 circuitry. Multiple channels 164, one for each axle end or tire. wiU connect to a control and display microprocessor 162. RF channel 164 includes the foUowing circuits: a printed

RECTIFIED SHEET (RULE 91) antenna 166 for mounting in the vehicle's wheel weU near a tire; an RF oscillator 168; an RF modulator 170; an RF transmitter amplifier 172; a gate generating circuit 174; an RF blocking circuit 176; and a receiver anφlifier/demodulator 178. A channel code generator/shift register 182 outputs data for modulation on local osciUator RF and transmission. Control and display microprocessor 162 is a conventional microprocessor circuit with a memory, a CPU, input output circuits, data and address busses, and timing/interrupt circuits. It interfaces with a user control panel 184 and a system display panel 182. These, too, are conventional, commercial type display and switch panels. FinaUy, an optional vehicle interface circuit 186 provides a means to integrate the system with existing vehicle displays and data sources.

Operation of Valve/Transducer and System

Mechanical Function

Air pressure from 137.9 kPascal (20 psi) (e.g., low pressure recreational aU-tenain vehicle) to

4137 kPascal (600 psi) (e.g., high pressure aircraft tire) is contained in fully inflated pneumatic tires. The tire, considered for this discussion a flexible pressure container, connects with an unclosed opening of stem 20 at its distal end. Valve core 24 as instaUed in stem 20 is a pressure barrier which can be opened or closed to add/release air from the container or seal the container and retain the intemal pressure.

Inflation starts with cap 28 removed. Manual attachment of an air-hose chuck to the proximal end of housing 90 distaUy depresses pin 34 which displaces cup 32 and its seal 36. The displacement is sufficient to open a gap between seal 36 and banel 30 which opens the valve so that the container receives air from the air-hose. Removal ofthe air-hose chuck releases pin 34. This permits spring force of spring 38 to displace cup 32 and seal 36 to their original closed position. Differential pressure between the distal side of cup 32 and the interior of banel 30 also acts in a closing force on seal 36. Upon completing inflation, cap 28 is instaUed. This connects battery 116 to electronic circuits in core 24 and transponder 26 and encloses the low pressure region between the interior of banel 30, proximaUy extending through banel 92 to cap 28. The completed assembly of stem 20, transponder 26, and cap 28 form a continuous protective barrier between the assembly exterior environment and electrical connections,

RECTIFIED SHEET (RULE 91) components, and circuits inside. Cap 28 also serves as replaceable energy source and it can be removed and replaced in the event of battery discharge, for example, without disturbing the installation of core 24 or transponder 26 or their electrical interconnection.

The exposed distal end of IC 44 communicates the tire interior pressure to diaphragm 60 of transducer 58. The pressure exerts a flexing force on diaphragm 60. The value of strain produced on diaphragm 60 is dependent on the equivalent spring rate of IC 44's silicon material and its thickness. Both parameters wiU be known with high precision - a result ofthe n- cro-machining process. Piezo-resistors 62 either increase or decrease their resistance in accordance with their specific location in transducer 58 and the value of strain at the resistor.

However, piezo-resistors 62 wiU also change resistance in accordance with temperature. Electronic circuits of IC 44 are ananged to both compensate for this temperature dependence and to detect and anφlify the smaU strain dependent resistance changes.

Electronic Functions

Bias circuit 126 connects to bridge 64 through three terminals as shown in figure 8 A. The first bias mode is as foUows - voltage bias is apphed to the center terminal and outer terminals are either, shorted together and biased with a cunent source, or each separately biased with individual but matching and tracking cunent sources. In this bias mode, the voltage differential output by bridge 64 to amplifier 122 wiU predominantly be determined by strain produced on diaphragm 60 by the apphed pressure. Temperature dependent enor terms will add to the differential voltage and must be compensated.

In the second bias mode temperature variation of bridge piezo-resistors 62 wiU predominate the differential bridge output voltage. This bias mode separately biases the outer terminals with positive cunent on one terminal and a matching value, opposite polarity (negative) cunent on the other terminal. Strain dependent variation of piezo-resistors 62 values wiU effectively appear as a common mode voltage enor from the bridge circuit 64's output. Calibrator 128 wiU compute products ofthe first (strain predominant) and second

(temperature predominant) ADC signals with transducer mathematical model coefficients. It wiU apply these conection values to the unconected ADC signals to calibrate the pressure

RECTIFIED SHEET (RULE 91) ISA/EP and teπφerature outputs ofthe system. Manufacturing tolerances of piezo-resistors 62 (e.g., up to 20%enor in absolute resistance value from IC wafer to wafer, although resistance ratios wiU be precise - approximately 0.1 % enor) and other fabrication variables wiU be cahbrated by specific model coefficients programed into EEPROM 70.

Further processing of tire inflation parameters involves conecting for the pressure temperature relation of gases in fixed volumes (only an approximation since the tire air container is flexible). As necessary, the processing wiU also conect for the variable stiffness of tire sidewaU with pressure and teπφerature which is parameter that changes the container volume. Another is variation in elasticity of tire material with teπφerature. A teπφerature, pressure mathematical model ofthe desired specific tire models (or type) wiU be programmed into EEPROM 70. EEPROM 70 wiU also contain a serial number code which has additional utihty when used with chassis subsystem 160.

Other embodiments of my valve/transducer invention wiU use the same processing algorithms described above but may use a different implementation of a digital ALU 68 or algorithm processor. In particular, these algorithms are suitable for computation in integrated transponder digital circuits (not shown) or in remote microprocessor 162.

The Manchester serial data interface was previously described to be a bidirectional self- clocking protocol controUed by sync and timing signals originating in receiver circuits 144 and 146. A further refinement ofthe operational description ofthe reception/transmission process is needed. There wiU be operations involving multiple transponder 26 simultaneously receiving RF intenogating signals (e.g., multiple tires at an axle end and multiple axles in close proximity as is eighteen wheel tracker/traUer or aircraft landing gear). Such multiple reception can come with use of either hand-held assembly 120 or chassis subsystem 160. To provide robustness to system operation, additional protocol is implemented in receiver circuits 144 and 146 and in code generator 180. This protocol involves sequential selection of specific transponder transmission of data. Gate circuit 146 recognizes demodulated intenogation codes in transmissions from RF channel circuit 164 and responds to a selection match/mismatch of intenogation code with EEPROM 70 device serial numbers. If there gate

RECTIFIED SHEET (RULE 91) ISA/EP circuit 146 detects a match it enables the transmit gate. Otherwise it leaves the transmit gate disabled.

Additional selectivity is provided in channel receiver 178 between potential overlapping transmissions from multiple transponders 26. Transmission of valve core 24 serial number also aUows remote processing to unambiguously display the location on the vehicle of tires which require maintenance. For example, using chassis subsystem 160, it is possible to automaticaUy detect a rotation of tires from one axle to another via the transmitted valve core serial number. This leads to a mechanization whereby the display microprocessor 162 generates an advisory message to that a recommended rotation interval is due or has been exceeded. Microprocessor 162 wiU also retain a non-volatile memory of tire pressure history (statistics) and estimate vehicle load increases or decreases using past statistics, recent pressure/temperature values, and cunent pressure/temperature values from aU vehicle valve core 24 in tires and suspension components (i.e., gas pressurized shock absorbers, air cushion bladders, etc.). Cautionary display indica wiU include displays which inform vehicle operators to add air under higher weight loading. Warning indica wiU include unsafe tire pressure and/or tire operating temperature. Advisory indica wiU include displays which inform operators about "optimal" gas mileage operating conditions or "optimal" tire life operating conditions.

Figure 9 shows a hand-held remote processing and display device 120 communicating via RF transmission and reception with my invention's combined valve core 24 and transponder 26 instaUed on a tire. Processing, functions, and electronic diagram are similar to those for chassis subsystem 160 with two minor exceptions. A single RF channel interface 164 is required. Vehicle integration input/output circuit 184 is not required or implementable. Other means of operating the apparatus are also possible. For example, in the case of use with a bicycle or motorcycle, a satisfactory mode of operation could eliminate RF transponder circuits. This mode could use a flashing LED and/or piezo-electric intermittent buzzer (i.e., a beep) in cap 28 to catch the attention ofthe vehicle rider.

RECTIFIED SHEET (RULE 91) ISA/EP Assembly/Installation Features

During instaUation of valve core 24 into stem 20, it is important that nut 42 rotate with respect to gasket 40. This avoids "screwing" gasket 40 into its final compressed location against stem 20's seat. Instead gasket 40 wiU axiaUy translate into place and undergo only a relatively smaU displacement after mitiaUy contacting stem 20's seat. To allow the rotation of nut 42 with respect to the remainder of valve core 24 assembly, nut 42 has a clearance opening for flex 76 which extends proximaUy through nut 42. This is a slight modification in form from the seating nut of prior art valve core 20. The tool for torquing nut 42 wiU be appropriately changed, but this is a minor issue.

After installation of transponder 26 onto stem 20 the position of connector 94 wiU be randomly oriented with respect to flex 76 and connector 86. Therefore, flex 76 must have sufficient service slack to adjust to any angular position of connector 94. Yet the service slack must not interfere with operation of pin 34 or extend into the proximal opening stem 20 where inflating chucks could crimp or pinch its electrical conductors or insulation. The twist capsule 76' formed in flex 76 by retainers 82 and 84 provides a means to manage the service slack. It aUows rotation of flex 76 through more than a fuU turn which is adequate to position connector 86 properly with respect to connector 94. Rotation in the twist capsule keeps the proximal end of flex extended axiaUy for proper ahgnment of mating connections of connectors 86 and 94.

Description of Other Embodiments

I considered other embodiments of my valve/transducer and system invention. I chose the embodiment presented above because it partitioned functional elements to system components in a manner which is flexible for apphcation and economical for production. This is somewhat indicated by the flexibility of apphcation evident in above descriptions of both hand-held unit 120 and chassis subsystem 160, but the prefened embodiment does more. For example, using a digital serial interface between IC 44 and transponder 26 optimized flexibility of implementing useful variants. Without modifying the design or manufacturing process of IC

RECTIFIED SHEET (RULE 91) 44 and changing only transponder 26 to a non-RF variant, it is possible to easUy apply my valve core invention to refrigeration systems which also use valve cores. In this case the non- RF "transponder" (not shown) wiU contain an electrical connector for interfacing transducer data (i.e., via wire harness) to a conceivable buUt-in-test circuit retrofitted elsewhere in the refrigeration system. In this case, electrical power can be provided by the external circuits.

The cap for this variant wiU be a conventional dust cap. A refrigeration system as described here is an inexpensive retrofit onto existing systems which, by gauging coolant status during normal operation, can eliminate costly periodic coolant service checks.

The inclusion of calibration and tire modeling processing in IC 44's functionality also enables this technology to be apphed to very low cost tire alarm systems which wiU also be non-RF variants. This wiU considerably extend commercial opportunities to apphcations such as bicycles and motorcycles and widen the automotive use. For these non-RF variants valve core 24 and IC 44 remain unchanged. However, a non-RF variant of a "transponder" (not shown) will interconnect the alarm discrete signal to cap 28 containing a battery and an alarm (e.g., a flashing LED and/or an audible beep). The "transponder" of this apphcation wiU also a battery voltage momtor to signal replacement of cap 28's battery if necessary. The indica for low battery wiU be distinguishable from tire alert indica.

Other Embodiments (Figure 10)

Figure 10 shows portions of significance for other embodiments of my valve/transducer and system invention. For example, figure 10A shows one of several pressure transducer alternatives to transducer 58. In the figure for a fiber optic valve core 196, as shown, a pressure transducer 198 interfaces with a high-quality optical polymer fiber interface 200.

Transducer 198 can be implemented with known photonic or fiber-optical technology consisting of a very simple microstructure. A first microscopic suspended silicon beam attaches at both ends to a silicon diaphragm substrate. This first beam has a natural resonant vibrational mode whose osciUation frequency depends upon tension exerted by the pressure diaphragm in strain. Its resonant frequency wiU also vary as a function of temperature. A second microscopic suspended silicon beam is free at one end and therefore has a vibrational mode with osciUation frequency dependent only on teπφerature. Each suspended beam is

RECTIFIED SHEET (RULE 91) ISA/EP excited into resonance by pulsed light from fiber 200. Fiber 200 also receives reflected light from the vibrating beams which is detectable by conventional photonic and electronic processing techniques. In valve core 196 implemented thusly, transducer 198's silicon substrate will be a passive (i.e., non-electronic) mechanical structure. Signal processing circuits and fiber-optical LED's and coπφonents wiU be added to RF circuits in a transponder structure similar to 26. However, a photonic transponder (not shown) is also feasible.

Other embodiments involve alternatives in placement of components within a valve core structure. For example, figure 10B shows how a silicon nήoOmachined pressure transducer die 204 can be placed on the distal end of a valve cup 202. In this embodiment die 204 is in pressure communication with tire interior pressure and interconnecting wires pass through a hoUow pin actuator 206 from distal end where they bond to die 204 input/output pads to a proximal end electrical connector (not shown). Adhesive filling in hoUow pin 206 seals the pressure barrier.

Other mounting positions of a pressure die 204 are possible as shown in figure IOC. This figure shows a banel 224 constructed in two parts for weldable assembly. Prior to welding, pressure die 204 is adhesively mounted to pedestal 226 which coπimunicates through a pressure sampling hole 228. Thus the underside of die 204 is in pressure coinmumcation with me tire interior pressure through hole 228. Die 204 interconnects via a flex circuit (not shown) sinular to flex 76. After conventional wire bonding between flex circuit and mounted die, then banel top assembly mounts over the distal assembly. Weld techmques similar to standard electronic nianufacturing processes permanently attach the assembly parts.

Partial Listing of More Embodiments

The foUowing paragraphs contain, without figure reference, additional altemative embodiments. These are examples of embodiments within the scope of my claims. However, the list presented here should not limit the claims.

Alternative Forms

There are altemative forms of various parts described earher. Some of these are:

RECTIFIED SHEET (RULE 91) ISA/EP banel indentation 45 in alternate position or shape; pin 34 in alternate shape; nut 42 in alternate shape; IC 44 in alternate shape, dimension, and/or construction; transducer 58 in absolute pressure measuring form; transducer 58 in differential (or gauge) pressure form; IC 44 with multiple transducers 58; spring 38 in alternate positions or shapes or in multiple combinations; flex circuit 76 with alternate shape or with fewer or with more coils; transponder 26 and/or cap 28 in alternate shape or dimension; alternate forms of hand-held unit 120; alternate forms of chassis subsystem 160 and or its components; alternate indica or controls and/or outputs; alternate materials for any or several parts (e.g., a molded ceramic banel with multi-layer printed conductors); combinations of several or many ofthe above listed altemative forms.

Alternative Functions

There are many alternative enibodiments which involve modification of functions described earher. With regard to pressure transducers) sensing method alone there are many, such as: a pressure transducer with capacitive sensing; a pressure transducer with photonic sensing (e.g., as described earher and others); a pressure transducer based upon electron tunneling cunent; a pressure transducer with surface machined three-dimensionaUy released microstructures in vibration and/or static displacement sensing; microstmcture pressure switches; combinations or variation of these. Other altemative function embodiments include: flexible fiber-optic interface between a valve core and transponder; alternate asynchronous serial data between a valve core and transponder; transmit only RF circuits in a transponder equivalent assembly; variations in data interfaces; photonic rather than RF transponder circuits; combinations of several or many of these. There are altemative energy sources to a battery which can be conceived - such as a miniature AC generator in a cap. For example a generator comprised of a imbalanced high flux magnetic rotor (imbalance causes rotation when vehicle operates) suspended by jewel pivots in a wire-wound stator. Altemative function forms include: analog signal processing substituted for digital signal processing or vice-versa; altemative processing algorithms or mathematical models; systems without battery conservation circuits; systems which have more or less integration with vehicular displays, processors, or data sources; valve cores with electricaUy operated (solenoid coU) valve cups wherein proximal end of actuating pin becomes a miniature switch; valve cores with microstmcture valves and actuators wherein pin becomes a miniature switch; combinations of several or many of these.

RECTIFIED SHEET (RULE 91) Natural Extensions

There are also embodiments within the scope of my claims which are natural extensions ofthe above. These include a miniature transducer only (i.e., without valves) wherein banel 30 is closed at its distal end and pin 34, cup 32 etc. are omitted. Such a miniature valve wiU be much smaUer than present electronic pressure transducers which are commerciaUy produced.

In general these are packaged according to constraints of present electronic printed wiring substrates (e.g., printed wiring boards, ceramic and MCM substrates - and generaUy in more or less rectangular sohd shapes). Apphcation of these transducers requires mechanical "plumbing" to pipe pressure to input ports on the devices. My invention as a transducer can be significantly smaUer. Preparation of an apphcation wiU be simply a matter of drilling, boring, and tapping an appropriately dimensioned and finished hole in a pressure container and instaUing my invention. Electrical connection to a connector within the instaUation nut wiU provide an extremely adaptable interface without expense, size, and weight of mechanical "plumbing". Transducer core dimensions can be much smaUer than valve core dimensions enabling lightweight but powerful pneumatic actuator systems to be constructed.

Another natural extension is incorporation of electronicaUy controUed micro valves implemented in the same microstracture substrate as the pressure transducers.

Further amplifying the embodiments there are combinations involving elements the multiple lists expressed above.

Conclusions, Ramifications, and Scope

My valve/transducer invention successfuUy implements a novel concept in the primary field of pneumatic tire pressure gauging and inflation alaπning in combination with tire inflating valves. Numerous prior art inventions have failed to solve the sigmficant technical problems addressed by my invention. Evidence ofthe novelty ofthe present invention is the teaching away from its approach by the prior art both in the primary field of invention and in systems of other types. Accuracy of pressure measurement provided by my invention enables

RECTIFIED SHEET (RULE 91) ISA/EP advanced condition assessment by digital processing which is also a subject of my invention. More informative displays of tire condition and status wiU enhance the useability and hence the marketabihty of my system.

My valve core design and associated system components addresses commercialization ofthe potential market in this field of invention with a design suitable for the broadest possible range of apphcations. This is in contrast to prior art whose designs relegated potential products to minor niche markets. My valve/transducer and system invention has high potential to capture a significant share ofthe available market. The components are relatively simple to constmct and assemble at economical prices and the design provides useful features which wiU attract consumer interest.

The ramifications of my invention extend significantly beyond the scope ofthe primary field of the invention. I have presented many altemative embodiments which relate to the field of mvention and their natural extensions. The scope of the described embodiments is broad. The various combinations of embodiments is broader stiU but it is impossible to present aU possible embodiments.

Thus the scope of my invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.

RECTIFIED SHEET (RULE 91) ISA/EP

Claims

Claims:

I claim:

l. A valve/transducer and system ofthe type comprising:

(a) said valve/transducer comprising: an appropriately dimensioned tapered banel of rigid material having a gasket near a proximal and larger diameter end of said banel, a closable opening through said banel in a location distal to said gasket, a closing means, a pressure transducer means, and a first signahng means, and

(b) additional system coπφonents comprising: a second signaling means selected from the group consisting of wireless transmitter/receiver paired circuits, optical transmitter/receiver paired devices, and electrical wiring, and a signal processing means, and an indicating means.

2. The valve/transducer of claim 1 wherein said tapered banel has a rotationaUy free attachment to an instaUation means, said attachment being proximaUy located on said banel such that said installation means wiU secure said banel in an appropriately dimensioned tapered bore hole in a pressure container waU or similarly in an appropriately dimensioned bore in a tube without causing said banel to rotate with respect to said bore during instaUation.

3. The valve/transducer of claim 1 wherein said pressure transducer means comprises a stmcture, three-dimensionaUy miCTomachined from a planar substrate of material suitable for pressure transducer constmction.

4. The valve/transducer of claim 1 wherein said first signahng means is composed of an integrated circuit and an electrical interconnecting circuit.

5. The valve/transducer of claim 1 wherem said pressure transducer means and said first signahng means are combined in an integrated circuit.

RECTIFIED SHEET (RULE 91)

6. A transducer and system ofthe type comprising:

(a) said transducer comprising: an appropriately dimensioned tapered banel of rigid material having a gasket near a proximal and larger diameter end of said banel, said banel being closed distal to said gasket, a pressure transducer means, and a first signaling means, and

(b) additional system components comprising: a second signahng means selected from the group consisting of wireless transmitter/receiver paired circuits, optical transmitter/receiver paired devices, and electrical wiring, and a signal processing means, and an indicating means.

7. The transducer of claim 6 wherein said tapered banel has a rotationaUy free attachment to an installation means, said attachment being proximaUy located on said barrel such that said installation means will secure said banel in an appropriately dimensioned tapered bore hole in a pressure container waU or similarly in an appropriately dimensioned bore in a tube without causing said banel to rotate with respect to said bore during instaUation.

8. The transducer of claim 6 wherein said pressure transducer means comprises a stmcture, three-dimensionaUy rnicromachined from a planar substrate of material suitable for pressure transducer constmction.

9. The transducer ofclaim 6 wherem said first signaling means is composed of an integrated circuit and an electrical interconnecting circuit.

10. The transducer ofclaim 6 wherein said pressure transducer means and said first signaling means are combined in an integrated circuit.

11. A system for pneumatic pressure measuring comprising :

(a) a transducer selected from the group consisting of miniature valves with combined

RECTIFIED SHEET (RULE 91) ISA/EP pressure transducer and niiniature pressure transducers, wherein said miniature valve comprising: an appropriately dimensioned tapered banel of rigid material having a gasket near a proximal and larger diameter end of said banel a closable opening through said banel in a location distal to said gasket, a closing means, a pressure transducer means, a threaded rotating instaUation means, and a first signahng means, and wherein said mimature transducer comprising: an appropriately dimensioned tapered banel of rigid material having a gasket near a proximal/ larger diameter end of said banel, said banel being closed distaUy to said gasket, a pressure transducer means, a threaded rotating installation means, and a first signahng means, and (b) a processing and indicating means comprising: a signal processing means, an indicating means, and a second signaling means selected from the group consisting of wireless transmitter/receiver paired circuits, optical transmitter/receiver paired devices, and electrical wiring.

12. The system ofclaim 11 wherein said signal processing means is coπφosed of:

(a) a transducer pressure enor cahbrating means providing a cahbrated pressure signal output, and

(b) a pressure mathematical modeling means used in evaluating said cahbrated pressure signal with respect to its being numericaUy less than or greater than a predetermined limit value.

13. The system ofclaim 12 wherein said calibrating means includes temperature measuring and processing.

14. The system of claim 11 wherein said mimature transducer is sufficiently smaU for instaUation in present commerciaUy used bores selected from a group consisting of pneumatic tire inflating stems, refrigeration gas charging tubes, pressurized vehicular shock absorber charging tubes, tubes for pressurizing vehicular st ts, and pressurized air cushioning bladder inflating stems.

RECTIFIED SHEET (RULE 91) A/EP

15. The system of claim 11 wherein said pressure transducer means comprises a structure, three-dimensionaUy microπ-achined from a planar substrate of material suitable for pressure transducer construction.

16. The system of claim 11 wherein said first signaling means is composed of an integrated circuit and an electrical interconnecting circuit.

17. The system of claim 11 wherein said pressure transducer means and said first signaling means are combined in an integrated circuit.

RECTIFIED SHEET (RULE 91)