This invention is directed to pressure gauges generally, but more particularly to a pressure gauge which can ^" be screwed on to a valve stem or continuously mounted to the inflated device.

BACKGROUND

Maintenance of gas pressure within an inflated device is a desirable effect particularly in tires used on motor vehicles. Through maintenance of proper tire pres¬ sure levels the vehicle is made safer, improved tire wear ^• •is achieved and better gas mileage- obtained. An added benefit of improved tire wear and gas mileage through " proper inflation is a reduction in the demand on our precious oil reserves - a fact of major significance in this day of energy conservation consciousness.

Also, continuously monitoring, attachable or direct mounted gauges have been developed. These, typi- cally, provide for a continuous monitoring of the tire pressure but, with the exception of a few devices recently developed, they preclude the inflating of the tire when required without first removing the gauge from the valve stem. More recently, however, gauges have been developed which are directly mounted to the tire and which also allow for the pressurization of the tire while it is in place. Such gauges are described in U.S. Patent Nos. 3,451,418 and 3,592,218.

The particular device described in the former ^• patent, however, is a rather complex apparatus. This can be concluded from a casual glance at the various figures of the drawings.

The device described in the '218 patent is com¬ plex to operate requiring the operator to hold the body of the gauge with his thumb and forefinger to twist it, while observing the extended gauge portion (which protrudes into the cup formed by his hand such that it is partially

OMPI

A,, WO -Λ/

obscured thereby). Purther, this gauge is inordinately long. Also, when one is filling a tire through such a* gauge, the operator is required to remove the air hose, grasp the body as above, not the pressure, reapply the air hose, etc., until the desired pressure is achieved - a relatively lengthy process.

It is a primary object of this invention to provide a pressure gauge which in line with the simplicity of the overall gauge,, provides a simple means for inflating the inflatable device when the gauge is in place and which includes means for sensing the pressure of the device with¬ out removing the gauge.

It is a primary object of-the best mode of the invention, as presently contemplated, to provide a gauge which includes a doubling back of the pressure monitoring portion of the gauge to thus reduce its length and so as to avoid interference problems with curbing.

It is a further object of the adaptation of this invention which includes the doubling back feature, to provide a gauge which utilizes standard valve and other related parts, for simplicity of design and economy of manufacture.

It is an object of various adaptations of this invention to provide a pressure gauge for an inflatable device which can be detachably mounted to the device and which is simple in construction and consequently, inexpen¬ sive to fabricate.

It is an object of another adaptation of this invention to provide a simple means for "sealing" the gauge upon rupture of its elastomer!c part, thereby pre¬ venting further leakage from the inflated device.

It is an object of yet another adaptation of this invention to provide a gauge which continually monitors the pressure of the tire and which allows the operator of the vehicle to tell from afar, whether or not the device pressure has deviated from a previously set pressure.

It is an object of one adaptation of this inven¬ tion to provide a pressure gauge for an inflatable

w c s e ac a y moun e o e ev ce an c s simple in construction and consequently, inexpensive to fabricate. It is yet another important object of the inven¬ tion to provide a gauge which includes a doubling back of the pressure monitoring portion of the gauge to reduce its length, thus avoiding interference problems with curbing. It is a further object of this invention to pro- vide a gauge v/hich utilizes standard valve and other related parts, for simplicity of design and economy of manufacture. DISCLOSURE 0_P THE INVENTION This invention describes a pressure gauge for measuring the pressure of an inflatable device v/hich in- eludes a design which is affixed to a standard valve stem as the latter is already in place on a tire rim. A second design of this embodiment includes a standard valve core assembly as part of the gauge itself with the composite in¬ serted in a tire rim as a single gauge-valve unit. In both of these designs, air is released into the gauge proper only when the pressure reading stem is actuated. The re¬ leased air is directed axially away from the valve stem initially by a first channel, and into a second channel, disposed transversely to the first channel. The latter directs the air radially outward from said first channel and into an airtight enclosure of variable volume. The latter is formed by a piston-like member disposed in a cylindrically shaped enclosure positioned concentrically outward of the valve stem. It increases in volume in re- sponse to increasing gas pressure, in an axial direction, toward the inflatable device.

Calibrated spring means control the variation of the volume such that the variation is proportional to the pressure of the released gas. The piston-like member is suitably marked, for example, with a colored circumferential band. Eor a given gas pressure, the piston-like member is displaced such that the band aligns itself opposite the appropriate psi indication disposed on a transparent outer

housing.

An alternate embodiment of the invention compris means defining a first enclosure, internal to which is an ^' 5 expandable, diaphragm-like material which is bonded in a suitable fashion to the first enclosure to thereby form an "airtight" secondary enclosure within the first. Inlet ports in the first enclosure allow for entry of pressurize gas from the inflatable device into the airtight enclosure 0 ^• Positioned on the longitudinal axis of the gauge is a shaftrϋke member, including a flanged end, adapted to operate the valve in the valve stem of the inflatable . device, when the gauge is in place on the valve stem. Thi releases the pressurized gas from the inflatable device 5 into the inlet ports previously mentioned. The shaft ex¬ tends the length of the gauge and has a bushing positioned on the end opposite the flange end. The axial length of the bushing is such that when inflating means, like an air pump, is applied to the bushing end of the gauge, the 0 bushing cooperating v/ith the inflating pump moves the shaf axially towards the inflatable device. This enables the higher pressure gas in the inflating means to run the length of the gauge and enter the inflatable device.

As a pressure monitor, v/hen the bushing-shaft 5 is depressed by the operator's finger, the pressurized gas is released into the airtight enclosure, and the elastomer diaphragm expands in response thereto. It urges a piston¬ like member axially positioned outward of the diaphragm. The force exerted thereon by the pressurized gas acting 0 through the diaphragm, is counteracted by the calibrated spring means which resists-the actual movement of the . piston in a predictable fashion. The piston thus moves in a rel.ationship proportional to the pressure of the gas in the inflated device. The piston again is suitably 5 marked at a prescribed position along its axial length, which is coordinated v/ith psi indicia on the first en¬ closure forming means such that -it aligns itself v/ith that marking signifying the pressure of the gas then

internal to the inflatable device.

In this last embodiment, if the diaphragm rup¬ tures, the piston, spring and diaphragm are designed such 5 that they cooperate with each other to seal off the air¬ tight enclosure. This prevents leakage of the pressurized gas to the "outside world" through the gauge.

Alternate forms of this last embodiment of the invention call for replacing the diaphragm as described 0 above v/ith a hollow- flexible tube or bellows or an "0-ring ^tt - sealed, piston arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and advantages of the invention will become more apparent from the following de- 5 tailed description and appended claims taken in conjunction with the accompanying drawings in which:

Figure 1 is an elevational view of one embodiment of the subject invention.

Figure 2 is a partial, cross-sectional, eleva- 0 tional view of the embodiment of Figure 1.

Figure 3 is a cross-sectional, elevational view of a part of the embodiment of Figure 1.

Figure 4 is a plan view taken along lines 4-4 in Figure 3« 25 Figure 5 is a perspective view of a standard valve core assembly.

Figure 6 is a cross-sectional, elevational view of the embodiment of Figure 1 being used in the reading mode. ~-Q Figure 7 is a cross-sectional, elevational view of the embodiment of Figure 1 being used in the inflating mode.

Figure 8 is a cross-sectional, elevational view of a modified version of the embodiment of Figure 1. 35 Figure 9 is a partial, cross-sectional view of one type of seal which can be used in the embodiment of Figure 1.

Figures 10, 11 and 12 are elevational views of

various adaptations of the embodiment of Figure 1.

Figure 13 is an elevational view of still another embodiment of the invention. Figure 14 is a plan view taken along lines 14-14 in Figure 13.

Figure 15 is a perspective view of the seal em¬ ployed in the embodiment of Figure 13.

Figure 16 is a perspective, sectional view talcen - along lines 16-16 in Figure 15.

Figures 17 and 18 are partial, sectional views of an.aspect of the design of the embodiment of Figure 13.

Figures 19, 20 and 21 are various alternative caps which can be employed with the various embodiments depicted.

Figure 22 is a perspective view of yet another embodiment of the subject invention.

Figure-23 is a cross-sectional, elevational view taken along lines 23-23 of figure 22. Figure 24 is a cross-sectional view taken along lines 24-24 of figure 23.

Figure 25 is a cross-sectional view taken along lines 25-25 of figure 23.

Figure 26 is a cross-sectional view taken along lines 26-26 of figure 23.

Figure 27 is an elevational view of the gauge of figure 23 being used in one mode of operation.

Figure 28 is an elevational view of the gauge of figure 23 being used in a second mode of operation. Figure 29 is an elevational view of a variation, in part, of the gauge of figure 23.

Figure 30 is an elevational view of a variation, in part, of the gauge of figure 23.

Figure 31 is an elevational view of a variation, in part, of the gauge of figure 23.

Figure 32 is an elevational view of still an¬ other embodiment of the subject invention.

Figure 33 is an end view of the gauge as shown

33-33.

Figure 34 is a perspective view of the gauge of figure 32.

Figure 35 is an end view taken of the gauge of .figure.34 as viewed in the direction of lines 35-35.

Figure 36 is an elevational view of the gauge of figure 32 shown in place on an inflatable device. , Figure 37 is an elevational view in section showing the gauge of figure 32 in cooperation with gas pumping means to inflate the inflatable device.

Figures 38 and 39 depict an improvement in one aspect of the embodiment of figure 32. Figures 40, 41 and 42 show in elevational, sec¬ tional viev/s, alternate adaptations of the embodiment of figure 32.

Figures 43 and 44 show in elevational, sec¬ tional viev/s, an application of the in situations wherein the gauge is supplied as part of the original equipment.

DESCRIPTION OF THE BEST MODS • Referring now to Figure 1, there is shown an em¬ bodiment of the present invention which implements the principles thereof. In this embodiment, gauge, 402, is designed to utilize standard valve cores v-zhich have been proven through many years of successful use. The gauge shown in Figure 1 employs an .interconnecting arrangement between the standard valve core and the end of the gauge v/hich interfaces v/ith the air pump. This arrangement enables the gas station attendant to utilize presently available valve core removal and insertion tools. He is thus able to follow the procedures he presently employs to ^' change or repair a flat tire without the need for any special tooling. The embodiment to be described employs a doubling back feature, v/hich results in a compact gauge avoiding in¬ terference problems v/ith curbing and the like. The present

embodiment can be mounted as an integral part of the rim and tire assembly with the attendant advantages of that arrangement.

One variation of the present embodiment includes a stem portion which is adapted to accept a plurality of spacer washers to achieve a sufficient distancing from the rim to allow the indicating portion of the gauge to be positioned outward of the wheel cover .for easy viewing. The stem includes a threaded end portion for mounting the gauge to the wheel rim. By moving the spacers from one side of the rim to the other, variations in the distance the gauge protrudes beyond the wheel cover can be achieved, thus accomodating various v/heel designs.

The second variation of the -present embodiment has the stem portion of the gauge embedded in a standard rubber mounting member which is pressed into the rim much like today's valve stem arrangements. This affords a fixe spacing for the gauge and it is most suitable for certain v/heel designs. The gauge of this embodiment lends itself to being bent at the stem portion to allow the upper part of the gauge to fold into the profile of the wheel eliminatin curb interference problems.

The present embodiment also employs improved indicating means resulting in more accurate readings by the user.

Referring now particularly to Figure 1, there is shown one variation of the present embodiment, 402, which includes an inflating and reading activating end, 404, contoured to interface with standard air pump equipment an to facilitate pressure reading by allowing use of the opera tor's finger to obtain a pressure reading.

The indicating portion of the gauge, 406, is dis posed in the mid portion of the gauge while the mounting thereof is effected by the spacer and nut arrangement shown at 408.

The indicating means, 406, can include number

indicia reflecting the pressure range of the particular gauge and serrations disposed about, the perimeter of the gauge for purposes of securing an 0-ring. (not shown) at a desired pressure level. However, where the gauge is sup- plied, for example, as factory installed equipment, on a given tire size, more often than not, the pressure for that tire will be constant at a particular psi. Thus, a painted ring, 410, would be positioned on the indicating portion of the housing at this particular pressure level. This ring v/ould work in conjunction with an indicator band, 412, internal to the outer housing, v/hich would move in response to actuation of the pressure reading mechanism, 404. When the indicator band, 412, is axially aligned v/ith the painted band, 410, the tire is properly inflated. Mounting means, 408, for securing the gauge to rim, 414, includes a plurality of spacer washers, 416, which are interposed between a shoulder on the upper portion of the gauge and the rim. The gauge with the spacers on the mounting stem thereof is placed in the accommodating hole in the tire rim and a sealing ring, 418, and back up washer, 420, placed on the stem and drawn up tightly to the rim by the double locking nut arrangement, 422 and ^" 424.

The plurality of spacer washers, 416, space the upper portion of the gauge from the rim so that the dis- tance, 426, between the rim and the wheel cover, 428, is sufficient to enable ready viewing of the gauge. The spacing,,430, is a function of the number of spacer washers employed and will vary depending on the particular wheel design. 432 shows the wheel-rim in phantom for that ar¬ rangement when the wheel cover, 428, is somewhat closer than that just described. Here the sealing ring, 434, is behind the rim with the spacers, 416 (although not shown in phantom) positioned on the gauge stem between the backup washer, 436, and the two nuts, 422 and 424.

For a particular stem length, all of the spacer washers, 416, must be employed, together with the sealing

rim," backup washer and double locking nut arrangement in order that the end of the stem, 438, is flush v/ith the ex posed surface of the nut, 424.

In a typical design, the spacers can provide 0. inches of adjustment in the length of the gauge protrudin outv/ard from the tire rim. By placing combinations of th spacers on either side of the rim the position of the gau outward from the tire assembly can be varied accordingly.

The mid portion of the gauge is preferably cove by. a rubber sleeve, 440, eliminating "chatter" which migh otherwise occur vith the banging of the gauge body agains the wheel cover, 428.

Referring now to Figure 2, there is shown a cut away, sectional view of this embodiment of the pressure gauge.

The gauge is seen to comprise an inner housing member, 442, which includes a first centrally disposed cavity, 444, extending a substantial part of the length o the gauge through the stem thereof at one end so as to be able to communicate with the inside of the tire. On the other end of cavity, 444, is a second cavity, 446, which is threaded in part and contoured to accept a standard valve core assembly. The inner housing further includes third cavity, 448, in which is disposed the inflating and pressure, reading connecting assembly, 404.

Through the wall of the inner housing surroundi the third cavity, 448, there is provided at least one radially extending through hole, 450.

The outside of the upper portion of the inner housing wall defining the third cavity can be threaded as shown at 452 in order to accept a valve stem cap for pur¬ poses of protecting the inner workings of the gauge from the elements and as a "seal" against any leakage which mi result if the core assembly malfunctioned. The outside circular wall, 454, of the inner housing is a tightly toleranced surface for purposes of t invention. The surface, 454, extends a substantial part

the length of the inner housing terminating in a first annular ledge, 456, which extends radially a distance until it is terminated by a second circular wall, 458, having a -diameter which is substantially concentric with the diameter of the first wall, 454. The second outer wall, 458, extends an additional axial length until terminated in a second annular ledge, 460. The latter terminates in an outer wall, 462, of the inner-housing.

The inner housing extends further to form a rim- mounting portion, 466, which has a smooth section, 468, extending a distance comparable to that taken up by the spacer washers, 416, and the .sealing ring and backup washer, 418 and 420. This insures an optimum seal by the sealing ring, 418, and the mounting stem of the gauge to avoid leakage therebetween. The mounting portion, 466, terminates in a threaded section, 470, for receiving the double nut arrangement, 422 and 424, which cooperate to se¬ cure the gauge to the tire rim.

The indicating means for this embodiment is shown at 474. It comprises an annular collar, 476, which has an inside diameter substantially equal to the diameter of the surface, 454, of the inner housing. The collar includes an annular groove, 478, which has a painted band, 480, on -the radially inv/ard surface thereof. The indicating means further includes a cylin- drically shaped extension arm, 482, which terminates in an annular flange section, 484.-

Positioned on the top surface, 485, of the collar, 476, is an annular, channel shaped portion, 486, which may -be formed as an integral portion of the indicating means member, 474, or be a separate piece which is commented to the top surface thereof.

The reason for the cylindrically shaped indicating means having a flanged end section, 484, is to eliminate the tendency for such a configuration to cock due to the unsyrαmetrical force exerted on the under surface, 487, of the annular collar, 476, by the top coil, 488, of the

spring, 472. The flange section is designed such that it will contact the inner wall of the outer housing before any significant tiiting of the collar portion can take place. The length of the extended arm, 482, takes into consideration the amount of tilt that might be expected due to this unsymmetrical force and the clearances and manufacturing tolerances of the involved pieces, so as to eliminate any significant tiiting. This design feature also eliminates scoring of the inside surface of the outer housing by the annular collar, 476. This insures continued visibility of the band, 480, over the life of the gauge.

Positioned in the channel, 486, is a T-shaped seal, 490. Its mating surface with the channel is-shaped and contoured to adapt readily thereto. The open portion of the V-shape is directed away from the channel.

Surrounding the inner housing, the calibrated spring, and the indicating means, is an outer housing member, 492. It includes an annular collar, 494, which has an inner diameter substantially equal to the diameter of the outer wall, 454. Extending axially downward from the collar as viewed in Figure 2 is an annular protrusion, 496, which includes at least one radially extending throug hole, 498, or slit cut into the protrusion. The hole, 498 communicates with the through holes, 450, via the annular cavity, 499. The protrusion at 496 includes an annular ridge portion; 500, which stabilizes the seal, 490, in the at-rest position to thus eliminate binding of the seal against the mating surfaces of the inner and outer housing. The housing further includes a cylindrical wall, 502, which extends a substantial part of the gauge, resting on ledge, 460. The inside surface, 504, of the wall is likewise a tightly toleranced surface and is concentric with the surface, 454, of the inner housing - in a typical situation to within a .001 inches. Radial hole,'464, is drilled through the wall, 502, and sleeve, 440, to reduce the back pressure behind the indicating means during opera tion.

A collar ring, 506, ^' is threaded on to the upper end of the inner housing and cemented to the top surface of the collar, 494, of the outer housing to keep the assembly intact and airtight. Referring now to Figures 3, 4 and 5, there follows a detailed discussion of the assembly and interconnection of the standard valve core assembly, 508, and the inflating- pressure reading interconnecting assembly, 404.

The inflating and pressure reading interconnect- ing assembly, 404, comprises an extension shaft, 510, which includes a cap portion, 512, connected to a cylindrical portion, 514. The latter is joined to a square or rectangu¬ lar section, 516, which terminates in a cylindrical cup - portion, 518. The cap portion of the shaft includes an arcuate section, 520, including, as is seen in Figure 4, flattened surfaces, 522 and 524, which facilitate use of a standard valve core removal tool to extract the interconnecting assembly from the gauge. The cap, 512, further includes a cylindrical disk portion, 526, which is disposed between the arcuate section, 512, and the cylindrical portion of the shaft, 514.

A bleeder hole arrangement including hole, 528, along the longitudinal axis of the shaft, 514, and a hole, 530, transverse thereto are drilled in the shaft and connect the top of the arcuate section with the cavity, 532, sur¬ rounding the shaft, 514.

The end, 534, of the cylindrical cup section, 518, is rolled over the raised portion, 535, of the valve stem, 536. This makes the extension shaft an integral part ^' of the valve core assembly.

The interconnecting assembly, 404, further com¬ prises a coupling collar, 538, which locks the extension shaft, 514, to the valve core assembly, to enable the integral unit to turn as if it were one assembly. The collar in the embodiment described is basically cylinαri- cally shaped with appropriately contoured cutouts which fit over coacting portions of the shaft extension and valve

core assembly. E.g., the upper portion, 540, of the co is either square or rectangular or can be keyed, whatev is appropriate, to be compatible v/ith the corresponding portion, 516, of the shaft. The lower portion of the c lar, includes a cutout, 542, which bridges the flats, 5 and 546, of the standard valve.core assembly, normally with an appropriate tool to remove that assembly from t tire.

Thus it can be seen that the collar, 538, loc by the upper cutout, 540, to the extension shaft and to valve assembly, 508, by the cutout, 542, provides for unison movement of the shaft extension and valve core a sembly v/hen rotated. Thus by connecting a standard val removal tool to the flats, 522 and 524, of the cap, 512 and rotating same, this rotational movement is transmit via the shaft, 514, to the standard core assembly, 508, enabling its removal from the gauge. This embodiment thus seen to utilize tools that are presently readily a able and not of special design. While the standard core assembly outlined is to be the type where the sealing spring is internal to core body, it should be apparent that this embodiment i readily adapted to utilize that type of core assembly w the sealing spring is external to the valve body. The interconnecting assembly, 404, further in cludes a butterfly valve, 548, which has an O.D. somewh larger than the I.D. of the inner surface, 550, of the inner housing and an inside diameter substantially equa the O.D. of the cylindrical portion, 514, of the shaft, The valve, 548, is made of an elastomeric material whic can withstand air pressures during _. the tire filling ope tion in excess of the pressure range of the gauge so th it is able to allow for the passage of air into the tir but prevent the leakage of air thereby during the readi mode.

The assembly, 404 , further includes a backup

v/asher, 552, which holds the butterfly valve, 548, against the disk portion, 526, of the cap through the force of spring, 554. ϊ e latter spring has an I.D. approximately equal to the diameter of the cylindrical portion, 514. The spring sits on the top of collar, 538, and is biased against the flat washer, 552, in the at-rest mode. The spring through its exertion of an axially directed upward force on the shaft, provides a positive force on the valve stem, 536, insuring that it is maintained in a closed position. - It also thrusts the butterfly valve upward to provide a tighter seal at the extremities thereof with the surface, 550. This inherently forces the operator to place his finger over the bleeder hole, 528, and to exert sufficient force when taking a reading so as to insure sealing thereof. To assemble the interconnecting assembly, 404, with the standard valve assembly, 508, before insertion into the gauge unit, the valve, 548, and flat washer, 552, are first placed over the shaft, 514. The spring and coupling collar are then set in place with the coupling collar forced up the shaft (as viewed in Figure 3) until the bottom thereof clear the cup, 518. The end of the cup, 534, is then rolled over the ridge,-535, thus making the two pieces integral, whereupon the collar is released.

Referring now to Figures 6 and 7, what follows is a description of the reading and filling operations employ¬ ing the embodiment of the gauge presently under discussion. Referring initially to Figure 6, the user in attempting to determine the tire pressure places a finger on the top of the gauge housing covering the hole, 528, and forcing the shaft, 514, downward. The bottom of portion, 516, of the shaft, moving axially, contacts the valve stem, 536, de¬ pressing it into the core assembly thus releasing the air from the tire. The released air follows the path of the arrows, 555, initially upward in the first channel, 556, . then transverse to that channel through a second channel formed by the radially disposed holes, 558 and 560. The released air passes into the enclosures on either side of the axially extending protrusion, 496, and exerts itself

symetrically on the upper surface of the seal, 490. The resulting force on the seal drives the extremities there against the -mating walls of the inner and outer housing and forces the indicating means,474, downward. The calibrated spring,- 472, resists this motion and when its displacement results in a force equal to that exerted by the air pressure, the indicating means assumes an equili rium position.

At that point, the painted band in groove, 478 is disposed opposite the appropriate indicia on the outs of the outer housing, 492, corresponding to the pressure within the tire.

Preferably the groove, 478, is cut deeply enou into annular collar, 476, so that the user must- view the band in the groove almost perpendicular thereto. Thus t distance, 566, between the actual psi reading and the apparent "psi reading" is minimized to reduce the parall error in gauge reading.

During the reading operation, because the fing is in place on top of the gauge, the released, pressuriz air is prohibited from venting from the gauge via holes 530 and 528. Also, the released air cannot escape past the butterfly valve, 548, because it is designed to resi the anticipated forces exerted thereon by the pressurize gas expected for a particular tire design.

After a reading with the finger removed from t gauge, the shaft, 514, is returned to the at-rest positi by the force exerted by spring 554 and the one in the co assembly. Yalve stem 536 closes, prohibiting further re lease of the pressurized air. The air trapped in the channels, 556, 558 and 560, and in the enclosure of varyi volume above the seal, 490, is bled off from the gauge through the holes 530 and 528.

Figure 7 depicts the filling operation. The ai pump nozzle, 568, is placed over the gauge as is normall done v/ith present valve core assemblies. The pressure o the air in the pump, is sufficient to force the perimete

of the butterfly valve, 548, downward allowing for the entry of the pressurized air into the gauge. For a typical design, this pressure requirement might be in the vicinity of 40 psi or greater. The nozzle, 568, contacts the button portion of the stem, 510, forcing the shaft downward such that it depresses the valve stem, 536. The pressurized air from ^* the pump proceeds down the channel, 556, into the core assembly, 508, and into the cavity, 444, v/hereupon it enters the tire. When the tire is at the anticipated pressurized level, the nozzle can be removed and the actual pressure checked according to the procedure set forth with respect to Figure 6. If more air is needed the nozzle can be replaced in position or, if in the first instance too great a pressure had been applied, the air can be released by successively depressing the interconnecting assembly allowing the air to vent through the bleeder holes 530 and 528.

Referring now to Figure 8 there is shown an al- ternate sealing arrangement to use in lieu of the butterfly valve previously described. The sealing valve assembly, 570, comprises a modified cap portion, 572, including an extended disk portion, 574, having an annular groove, 576, cut therein. Positioned in the groove is an 0-ring of appropriate elastomeric material.

The inner housing, 442, is modified from that described in Figure 2 so as to now include a cutaway por¬ tion, 582.

The distance between the location of the 0-ring and the top of the cutaway ^" portion is such that when the ^• stem, 584, is depressed for purposes of taking a reading, the 0-ring does not reach the cutaway portion, 582. This . prevents leakage of the released air past the stem and in¬ sures that it is directed into the area of the seal, 490, which reacts as described with respect to Figure 6. How¬ ever, when the tire is being filled the air pump nozzle depresses the stem, 584, more deeply into the body of the gauge such that the 0-ring now is disposed in the cutaway

area, 582. The dimensions of the O-ring are such -with re spect to the diameter of the cutaway section, 582, that t pressurized air from the air pump nozzle can pass there¬ between and thus fill the tire. Figure 8 also depicts an adaptation of the presently described embodiment of the invention which al¬ lows for its utilization as a gauge to be screwed on to a standard valve stem already .in place in a tire.

Referring now to figure 9 there is shown an alte native to the "V" shaped seal, 490, described in Figure 2. The annular ring seal, 586, comprises a central portion, 588, which is substantially rectangle in profile but in¬ cludes a groove cut therein at 590 which mates with the annular ridge, 500, of- the axially extended protrusion, 496. The annular ring, 586, further includes angled wing section, 592 and 594, which extend radially outward and inward, respectively, from the rectangular portion, 58 to provide a seal against the corresponding surfaces of th inner and outer housing. When the gauge employing the typ seal shown in Figure 9,is activated for purposes of obtain ing a reading, the released gas enters the enclosures, 596 and 598, as with the "Y" seal so as to exert an equal forc on each of the two annular wing sections. This insures that a symmetrical force is exerted on each of these sec- tions so that there isn't a "sticking" of the seal to one surface or the other due to an unbalanced force.

The seal may be bonded or cemented tothe annular collar, 476, of the indicating means, although this is not necessary. The collar is then driven downward in response to the force exerted on the seal in an identical manner as that described previously with respect to the "V" seal. The dimensions of the seal, particularly the annular wing sections and the material thereof are selected to provide an adequate seal against a blow-by of .. the pressurized gas but, at the same time, afford a minimu resistance to the force exerted by that gas in order that the seal not hang up.

Figure 10 shows an adaptation of the gauge of th

presently described embodiment which employs two painted bands, 600 and 602, on the* outer surface of the outer sur¬ face of the outer housing. This accommodates a typical situation found with respect to the pressure differential between tires located on the front wheels and tires located on rear wheels. Original equipment manufacturers can use this simple technique to preset the tire pressures for the front and rear tires for a particular tire size and vehicle. The tires to be used on the front of the vehicle would be pressurized until the indicator band, 604, aligns itself with the upper band as viewed in Figure 8 - representing the recommended tire pressure for front tires. The same would be done with respect to the rear tires except that now the tires would be pressurized until the band, 604, lined up behind the painted band, 600, set at the recom¬ mended pressure for the rear tires.

Thereafter, in use, an operator would only have to check the pressures in each of the tires to make sure that the band, 604, v/as aligned behind either one of the ' tv/o painted bands, 600 or 602 - depending on whether it v/as the front or rear tires. This convenience would eliminate the operator's need to refer to an owner's manual or the like to check the recommended pressure.

Figure 11 depicts a modification of the present embodiment where the mounting stem, 606, is bent to accom¬ modate those applications where an upright adaptation for the gauge might result in curb clearance problems. The bent stem folds the gauge body into the profile of the wheel thus avoiding these problems. Since only the stem is bent, the operation of the gauge is unimpeded and is identical to that described above.

Figure 12 depicts yet another adaptation of the* basic gauge design of this embodiment wherein the method for mounting the gauge body to the rim employs a standard valve seat, 608, which is cemented or otherwise affixed to the gauge body, 610. This ^' is a suitable means for securing the gauge to the rim in those circumstances where the wheel design is fixed and there is no need for the mounting

_ OMPI Δ

adjustment feature described above. ^' This is most appropri¬ ate again as part of the original supplied equipment.for a car where the design and profile of the wheel is known and can be accommodated. Referring now to Figure 13, there is shown still another embodiment of the present invention. The version of the invention depicted, as with the previous embodiment, utilizes standard valve cores but is a somewhat simpler and less complex version. It, too, employs the doubling back feature of the embodiment shown earlier and like the embodiment shown in Figures 1 through 12, it is mounted as an integral part of the rim and tire assembly either employing the threaded stem-nut connecting arrangement or the molded rubber adapta tion. ~

It is readily seen from the drawings* and the ac¬ companying discussion that practically all of the modifica¬ tions and variations described with respect to the earlier embodiment are likev/ise applicable to this adaptation. In the design shown in Figure 13, gauge, 700, includes an inner housing member, 702, having a first cen¬ trally disposed cavity, 704, communicating axially with a second cavity, 706, which is threaded and contoured, as at 708, to accept a standard core unit (see Figure 5), such as 710.

Cut into the inside threaded wall of the second cavity, 706, is an axially extending cutout, 712. This is better seen from the plan view in Figure 14. This runs parallel to the longitudinal axis of the gauge and provides a passageway whereby the cavity, 706, is able to communi- ' cate with an angled thru hole, 714, which, in turn, com¬ municates with the enclosure, 715.

As before, the outside wall of the second cavitj'" is threaded as at 716 to accept a standard valve cap or the dual purpose cap to be described hereinafter.

The outside circular wall, 718, of the inner hous ing extends a substantial length. At the tire end, an end

piece, 720, is press fitted thereon. The latter includes a first annular ledge, 722, which is terminated by circular wall, 724. Typically, the circular wall, 724", is concen¬ tric to within .001 inches of the surface, 718, of the inner housing.- The circular wall, 724, extends from the ledge, 722, to a second annular ledge, 726, which provides a flange surface against which.abuts grommet, 728, which is interposed before the flange and the tire rim, 730, and the threaded end, 732, of end piece 720. Nut 734 is used to secure the unit to the rim.

The upper end, .736, of the inner housing includes an annular collar, 738. This provides a ledge, 740.

Indicating means similar to the design previously described with respect to the embodiment in Figure 1 and following,is shown generally at 742. It includes an annular collar, 744, having an annular groove, 746, with suitable painting or other marling disposed therein. Although not as pronounced in this view as in Figure 2, it is understood, of course, that the groove 746 may be cut as deeply as in the earlier described embodiment with the attendant advan¬ tage.

The indicating means further includes a cylin- drically shaped extension arm, 748, connected to the annular collar, 744, and directed longitudinally towards the tire. This extension terminates in an annular flange section, 750.

Disposed on the top side of the annular collar, 744, is an annular, elastomeric seal, 752, which is cemented or otherwise secured to the top surface, 754, of the collar, 744. Biased against the undersurface, 756, of the collar, is the top coil, 758, of calibrated spring, 760. The bottom coil of the latter, 762, rests on the ledge, 722.

A cylindrically shaped, clear plastic housing, 764, forms the outer housing member and is disposed, between the ledge 740 of the inner housing member and the ledge, 726, associated with the end piece 720. The housing is bonded to the ledge at 740 to provide an airtight seal. The inside surface, 766, of this outer housing member is relatively tight toleranced and typically, concentric with

the surface, 718, again, to within .001 inches. Further, for purposes described with respect to the earlier embodi ments, the cylindrical wall includes a vent hole 768.

Because of the manner in which air is introduced into the expanding enclosure, and the particulars with re¬ spect to the design of the elastomeric seal, 752, it, typically, v/ill require means for keeping the seal from closing off the thru hole 714. This is accomplished with the use of a snap ring, 770, disposed in an appropriate groove in the inside wall, 766, of the outer housing member. The ring limits the upward movement of the indi¬ cating means so as ^' to prevent the constant spring force exerted by spring 760 from deforming and causing cold flow of the seal, 752, which would cause a v/edging effect and hinder the operation of the gauge.

As before, the gauge of the present embodiment can include an "anti-rattle" protective covering, 771 to eliminate noise between the gauge and the cover.

Referring now to Figures 15 and 16, there is sho an elastomeric seal which is considered to be of suitable design for this embodiment. It includes a semi-circular ridge, 772, which extends to angled wing sections, 774 and 776. The latter are then juxtaposed to the relatively rectangular section, 777. The seal rests on surface 754 o the collar 744 and may be cemented thereto if found neces¬ sary.

The ridge section, 772, of the seal includes a plurality of slits, 778, which affords appropriate passage ways for the air entering the enclosure, 715, to contact and coact with both of the winged sections, 774 and 776. This allows for a balanced force to be exerted by the air entering the enclosure on the seal, which, in turn, mini¬ mizes the cocking of the indicating means.

The ridge 772 rests in groove 779 when the gauge is not being used. The durometer of the elastomeric seal, 752, is chosen so as toavoid a closing down of the air passageways. This, plus the effect of the snap ring,

770, allows for the air to pass to either side of the ridge when the indicating means is in the at-rest position.

Referring to Figures 17 and 18, alternatives to the snap ring approach.of Figure 13 are shown. In Figure 17 an annular ridge, 780, is molded on to the inside wall, 766, of the outer housing member, 764. This ridge engages the flange, 750, and provides the necessary effect to keep the ridge portion, 772, of the seal from closing off the thru hole, 714. In Figure 18, a ledge, 782, is molded in the inside wall which coacts with the flange, 750, to achieve the same end.

Figures 19, 20 and 21 depict various cap designs which provide a normal closure for .the gauge and which in¬ clude on their opposite end, a means for actuating the valve in the embodiment shown in Figure 13, to thus allow the taking of a pressure reading.

Particularly referring to Figure 19, the cap, 784, includes a centerpost portion, 786, and a circular side wall portion, 788. These define an annular cavity into v/hich is placed a gasket, 790. The v/idth of the cavity is such that the cap may be placed over the end of the gauge just described without there being a significant lateral movement. This insures that the centerpost, 786 will contact the actuator portion, 792, of the valve core assembly. The gasket, 790, is disposed in the cavity and cooperates with the end of the gauge to seal that point to thus prevent the escape of air when the reading is being talcen.

Referring back to Figure 13, when the cap is * employed (or one's finger) to take a reading, air flows out of the tire, up through the standard core assembly, 710, and into the enclosure, 715, via the cutout, 712, and angled thru hole 714. The direction of air flow is shown by the arrow, 794, in Figure 13. The air entering the en- closure, 715, is directed onto the winged sections, 774 and 776, of the seal and exerts a force thereon to drive the indicating means downward until the painted groove, 746, aligns itself v/ith the corresponding pressure

The cap further includes a knurled section, -796, for ease of removal. The internal portion of the cap whic is normally disposed on the end of the gauge includes a cutout section, 798, of appropriate design so as not to actuate the end, 792, of the valve stem in the at-rest position. The internal portion of that end of the cap is threaded at 800 so it may be screwed on to the gauge. It

•J _Q may further include a gasl^et, ^" 802, to eliminate leakage.

Figure 20 show ^' s another adaptation of the dual function cap where the portion which interfaces with the gauge during the pressure reading mode includes a threaded inner wall, 804, v/hich screws on to the end of the gauge ■ _γ c until centerpost 806 contacts the valve actuator. Again, gasket 808 seals the end of the gauge to prevent leakage. Figure 21 shov/s a threaded centerpost, 810, λ-/hich screv/s into the gauge until the gasket, 812, seals off the end.

Although the various caps shown are metal and

20 employ gaskets to seal the gauge, it is understood that the cap can be made from a suitable elastomeric material which provides the means for sealing in and of itself.

The gauge depicted in Figure 13 is a lighter v/eight adaptation of the present invention which has less of an impact on the balance of the tire and results in

25 less stress on the rubberized mounting when such is used to secure the gauge to the tire rim. Further, the adapta¬ tion just described is smaller in diameter which enables it to be utilized with standard wheel covers.

30 Referring now to figures 22 th.ru 26, inclusive, there is shown another variation of the basic invention described herein, v/hich requires that the operator of the gauge depress the body portion of the gauge in order to obtain a pressure reading.

35 Figure 23 describes a preferred embodiment of such a gauge. It includes a first enclosure 200, formed between an inner housing 202 and an outer housing 204.

The tv/o housings are bonded together at annular seams ^* 206 and 208 to form the annular cavity identified as the first enclosure 200. The outer housing 204, is an inverted cylindri¬ cal cup made from a transparent material such as clear plastic. As viewed in figure 22, the exterior of the outer housing, 210, has embossed or imprinted thereon a range of numerals 212 corresponding to the range of pres- sures expected during the use of the gauge. The range of pressures can be postioned at annular increments around the outer perimeter of the housing so that the gauge provides the operator with a 360° readout capability. Further, groups of serrations (not shown) may be inter- posed betv/een each grouping of numerals to accommodate an "0-ring" indicating band (also, not shown, in the em¬ bodiment)• The outer housing is cutout at point 214 to accommodate an annular ring portion 216 of the inner housing. The inner housing, 202, includes a main, hollowed-out cylindrical portion 218. The housing in¬ cludes a cup-shaped portion defined by annular sidewall 220. The sidewall terminates at the one end by flanged portion 222. At the opposite end of the inner housing is located the previously identified annular ridge 216. As noted earlier the main portion 218 is hollowed-out to form a cylindrical opening 224 v/hich is threaded to ac¬ cept other parts of the gauge as v/ell as the standard tire valve. Thru holes 226 and 228 run through the main por- tion of the inner housing 218, transverse to the longi¬ tudinal axis of that member, near the annular ridge end. The circular flanged portion 222, includes an opening 230 v/hich is best seen in figure 26. Although not dis¬ cernible from figure 23, the outside wall 232 of the inner housing can have a slight taper to it, being in¬ clined towards the longitudinal axis of the gauge in the downward direction as viewed in figure 23. This reduces

OMPI

frictional forces as the "0-ring" is deformed under in¬ creasing pressures.

A second enclosure, of variable volume is forme within the first enclosure 200. The second enclosure 234 (best seen in figures 27 and 28) is formed by an "0-ring" 236, which is bonded to a piston-like, spacer member 238 by a suitable adhesive.

The "0-ring" is a standard catalog item having a thiclαiess in the plane perpendicular to the longitudi¬ nal axis of the gauge, which is slightly larger than the radial thickness of the first enclosure at its widest point, which because of the taper mentioned earlier, would be at the bottom of the first enclosure 200, as viev/ed in figure 23. The "0-ring" exerts sufficient pres¬ sure on the walls defining the first enclosure such that the leakage of the pressurized gas thereby is eliminated. The piston-like member 238, is an annular ring of suitable material which has a first surface 240 of con- cave shape to which the "0-ring" is bonded. The axially opposite face or surface of the ring 242 is substantially transverse to the longitudinal axis of the first enclo¬ sure but includes an interrupted, annular ridge 244 v/hich spaces the member 258 off from the inside surface 246 of the outer housing. As noted, the ridge 244 is interrupted at various locations around its circumference, such at points 248, 250, and 252 and 254 in figure 25, to insure that the pressurized gas can contact the maximum area on the surface 242. Although the "0-ring" and piston-like member are illustrated as separate pieces, to take advantage of the ready availability of standard sized "0-ring", it is understood that the piston-like member and "0-ring" can be molded from rubber or suitable elastomeric material and formed in one pieces with the profile shown in fi¬ gure 23.

Located in the central portion of the gauge is

the valve stem actuating mechanism which allows the operator to either take a reading of the pressure' in the tire or to inflate same if so desired. The gas releasing and inflating mechanism includes a cap portion 256, which includes a cylindrical cup portion 258 disposed axially from a flanged portion 260. Extending axially from the opposite side of the flanged portion 260 is a threaded cylindrical portion 262 which has an outside diameter corresponding to the inside diameter of cylindrical opening 224 in the main portion 218 of the inner housing. On the inside wall of cylindrical cup portion 258, there is an annular groove 264. The annular groove 264 bas a slanted lower edge 265 disposed axially inward from the upper end of the gauge. The cylindrical cup portion terminates at the uppermost axial end thereof, as viewed in figure 23, in a flanged portion 266 which slightly overhangs the cylindrical opening formed by the main portion of cup 258.

The flanged portion 260 of the cap 256 has an outside diameter (O.D.) equal to the O.D. of the outer housing 204. The under surface 270 of the flange can be bonded to the upper surface of the inner and outer housing by a suitable adhesive. This provides an ad¬ ditional airtight seal to eliminate a potential leakage path.

The threaded cylindrical portion or stem 262 is only threaded at the end thereof which meets with the threaded opening 224. The portion of the threaded stem 262 nearer the flange 260 has the threads removed. This provides an annular channel 272 which is contiguous with the openings 226 and 228. Further, the threaded stem 262 includes slots 274 and 276 running parallel to the longitudinal axis thereof which provide a channel for directing gas released from the inflatable device to the annular cutout 272 and thence, through the open-

ings 226 and 228, into the second enclosure 234.

The valve actuator member 278 is a cylindrical member having a U-shaped profile with an axially extend- ing pin member 280. At the axially upper portion of the actuator member, there is located a circular flange 282 having an O.D. substantially equal to the inner diameter of cup member 258. Located in the sidewall ^" 284 are thru holes 286 and 288. These form part of the channel for directing gas into the inflatable device.

A hose contacting member 290 includes a cylin¬ drical disc 292 and an axially extending, rod-like mem¬ ber 294 which makes contact with the valve stem in the air hose. Positioned at the axial upper end of the gauge is a retainer cup 296 including a main cylindrical por¬ tion 298 having a cylindrical opening 300 at the center thereof opening into a larger cylindrical opening 302 defined by sidewall 304. The main portion 298 includes an annular groove 306 in which there is disposed a suitable "0-ring" 308. The main portion 298 of the re¬ tainer cup is of appropriate diameter such that the flange 266 restricts the upward axial movement of the cup 296. Interposed between the upper surface of the disc 292 and the under surface of main portion 298 is a sealing gasket 310 which has an inside diameter sub¬ stantially equal to the diameter of rod member 294 and is thick enough in the horizontal plane, as viewed in figure 23, to seal off the cylindrical opening 300.

Positioned in the opening defined by sidewall 284 is a spring member 312 which contacts surface 314 of valve actuator member 278 on the one end and the surface 316 of disc member 292. Surrounding the sidewall 284 is a second spring

318 which on the one end contacts the under surface of flange 282 and on the other end the top surface of a spanner nut 320.

The spanner nut has a threaded, outside peri¬ meter whose diameter is equivalent to that of the cylin¬ drical opening 224. The nut includes an interior open- 5 ing 322 through v/hich the pin member 280 passes in the assembled position. Notches 324 and 326 allow for the use of a ^' spanner wrench in the assembly of the gauge. Positioned in the first enclosure 200 is a third spring 328 v/hich contacts the upper surface of 10 flange 222 at the one end and at the other end, a retainer spacer 330, which is bonded to the "0-ring" 236, at the opposite end. This third spring is cali¬ brated to control the movement of the piston-"0-ring"- retainer ring combination, in response, to air pressure, 15. such that the last mentioned combination settles at a postion.opposite the marking indicative of the pressure of the gas within the inflated device.

Although identified in the drav/ings as a separate piece, it is to be realized that the retainer 20 ring 330, may be molded to together v/ith the piston- "0-ring" combination mentioned earlier to form a one- piece unit.

Painted on the radially outward wall of the combination formed by member 238, "0-ring" 236 and the 25 retainer spacer 330, would be a suitabbly colored annu¬ lar ring 332 v/hich, of course, moves with those combined pieces to postiόn itself opposite the pressure indica¬ tion in the range 212 to reflect the pressure of the gas in the inflated device. The "0-ring", 236, itself 30 can provide the necessary indication without the need . or an additional painted band. Assembly

The gauge shown at figure 23 is assembled by first postioning the spring 328 around the main portion 35 218 of inner housing 302 and postioning above that, the "0-ring"-piston member-retainer ring combination 236- 238-330. The first enclosure is then formed by cement¬ ing the outer housing 204 to the inner housing 202 at the seams 206 and 208.

The cap portion 256 is threaded into the circu¬ lar opening 224 until the flange 260 contacts the top surface of the inner and outer ^' housing. As noted earlier the under surface 270 can be bonded to the upper surface of the inner and outer housing if desired.

Next the retainer cup 296, v/ith "0-ring" 308 in place, is inserted into the opening defined by cylin¬ drical portion 258. Then the hose contacting member 290, with gas¬ ket 310 in place is inserted through opening 300. The valve actuating member 278 with spring 312 postioned within the opening formed by sidewall 284 is inserted in¬ to the opening defined by sidewall 258. Spring 318 collars sidewall 284 and the spanner nut 320 is inserted into the opening 224.

The nut is threaded up into the opening until the bottom surface thereof, 334, is flush v/ith the bottom surface 336 of pin member 280. The length of springs 312 and 318 are selected such that when, surfaces 334 and 336 are flush, spring 318 is exerting an upward force on flange 282 while spring 312 is exerting an up¬ ward force on disc 292.

Space betv/een the end 338 of threaded stem 262 and the top surface of the spanner nut is provided to allow for adjustment of the spanner nut to compensate for that situation v/here the valve stem 340 is not flush with the top surface of the valve wall 342. Operation The gauge is threaded onto the valve wall 342.

The disposition of the first enclosure relative to the threaded opening 262 and the valve is such that the second enclosure 234 increases in volume in the direc¬ tion of the inflatable device as the pressure inside the device increases.

Referring particularly to figure 27, there is shown the use of the gauge described in figures 22 thru 26, as it is employed to read the pressure in a tire.

With the gauge in place on the valve wall 342, the operator places one of his fingers over the opening 302, depressing the retainer cup 296 by downward _. pres- sure of his finger. Since flange member 282 is kept in contact with the under surface of portion 298 of the retainer cup by spring 318, the valve actuator member 278 responds to the depressing force exerted by the operator and moves downward as v/ell. Pin member 280 contacts the valve stem 340 forcing it downward also. After approximately 1/32 inches travel, air is released from the inflated device traveling upward therefrom in the direction of the arrov/s. Air first travels through opening 322, into the portion of cylindrical opening 224 immediately between the top surface of the spanner nut 320 and the surface 338 of the* stem 262, and then upward through the slots 274 and 276 into the annular cutout 272. From there it travels into the second enclosure 234 via the circular openings 226 and 228. The force of the pressurized gas working on the surface 242 drives the piston-"0-ring"-retainer disc combination downward until the annular band 332 is postioned opposite the air pressure of the device.

Air is prevented from leaking out of the gauge during this operation, along paths 344 and 346 due to the sealing action of the "0-ring" 308 against the slanted lower edge, 268, of the annular groove 264 and by the sealing action of gasket 310, respectively.

When the operator removes his finger from the cup 296, the spring 318 having been compressed further by the action of the operator taking a reading, exerts a force upv/ard as viev/ed in figure 27 on the flange 282 such that the retainer cup is restored to the at-rest position shown in figure 23. Air trapped in the enclo- sure 234 slowly leaks out therefrom by passing betv/een the flange 282 and the cylindrical wall 258 and out through the groove 264 and the space betv/een the flange

O PI

266 and the sidewall 304.

The inflating operation can be best understood by referring to figure 28. This shov/s an air hose 348 connected to the gauge with the hose valv.e member 350 contacting the rod member 294 so -as to drive it downward relative to the retainer cup member 296. By depressing ^' the air hose contacter 290, the seal formed by.gasket 310 over the opening 300 is broken. Air released from the hose 348 moves along the path of the arrbv/s in fi¬ gure 28 into the opening 302, down through the opening 300, into the opening 352 and then into the opening 354 by way of the thru holes 286 and 288.

The air continues downward through the open- ing 322 and then into the cavity, defined by the valve wall 342. ^:

Simultaneously the valve stem 340 has been depressed sufficiently by the contacting action of the air hose valve gasket 356 contacting the sidewall 304 of retainer cup 296. As explained with respect to fi¬ gure 27, the downward force applied by the valve gas¬ ket 356 is transmitted through the retainer cup and the actuator member 278 to the valve stem. The seal¬ ing action formed by the cooperation between the "0-ring 308 and the slanted lower edge 265 of the groove 264 -prevents the entering air from exiting from the guage. Also, as the air hose is pressed down onto the gauge, gasket 356 contacts the top surface 357 of flange 266. This provides an additional seal. It is to be noted that in addition to inflat¬ ing the tire, pressurized air entering from the air hose 348 is also directed into the enclosure 234 via the openings 226 and 228. This provides a continuous monitor of the tire pressure while it is being inflated. Upon removal of the air hose from the gauge, the restoring spring 318 forces the actuator member 278 upwards until the main portion 298 of the cup contacts

flange 266 of the retainer cup 296. The "O-ring" 308 is then positioned in the annular groove 264. Pin num¬ ber 280 moves upward so that its lower end 336 is again 5 flush v/ith the surface 324, whereupon the valve stem 340 closes. Air trapped in enclosure 234 leaks out of the gauge in the same manner as described with respect to figure 27.

Referring now to figure 29, there is shown a ° gauge which is basically similar in all respects to that shown in figure 23 except that the means which coacts , with the valve stem either releases pressurized gas from the tire or responds to device inflating means to thus inflate the tire is simplified. In this adaptation the 5 retainer cup 296, actuator member 278 and hose contact 290 are replaced by a single actuating mechanism 358. The member 358 includes a hose contacting button 360 a main cylindrical portion 362 and a valve actuating pin

364. 0 The member 358 is positioned in cavity 366 formed by somewhat simplified cap portion 368.

The member 358 is captured in the cavity 366 and forced upv/ard therein by the action of spring 370 interposed between the under surface of cylindrical 5 portion 362 and the top of the spanner nut 320.

The operation of this embodiment v/ith respect to talcing a reading and, as well, inflating a tire is identical to that disclosed with respect to figures 27 and 28. The main difference here is that the sealing 0 action when taking a reading is performed by the opera¬ tor's finger alone. Likewise, when used in the inflating mode, the only seal preventing escape of entering air from the gauge is the one formed by the air hose gasket 356 and the top surface 371 of the cap. 5 Referring now to figure 30 there is shown a variation of the means employed for forming the variable volume enclosure. Again, the details of the construction

of the remainder of the gauge are substantially identi¬ cal to those associated with the gauge of figures 23 or 29. Here, the means forming the variable volume enclo- sure comprise an annular piston-like member 372 which has embeded in its radially inward and outward walls, "0-rings 374 and 376 of suitable diameter. As air enters the chamber 378 in either the pressure reading or inflating mode, the piston 372 travels within the volume 378 until there is equilibrium between the force exerted by the calibrated spring 380 and the pressurized ^' gas working on the surface 383 of the piston. An extension art 384 running axially along a part of the length of the gauge includes a flanged portion 386. On the radially outv/ard wall of the flanged portion 386 is painted a suitable annular band which would locate itself opposite the particular number on the pressure range located on the outer housing, corresponding to the pressure of the gas in the inflated device. Of course, the presence of the arm 384 is not necessary to the operation of the parti¬ cular, embodiment illustrated, and it is obvious that the "O-ring" 376 itself could perform the necessary indica¬ tion given a properly calibrated spring 380,

The walls 388 and 390 are again tapered rela- . tive to each other such that they move away from each other towards the bottom of the gauge as viewed in figure 30.

Referring to figure 31, there is shown yet another embodiment of the gauge which employs yet an- other means for forming the enclosure of variable volume. The remainder of the gauge is identical to either the embodiment of figure 23 or figure 29. Here, the "piston" member 392 is a cup shaped, annular member, which has flexibly inner and outer edges 394 and 396. The edges 394 and 396 are designed so as to be biased against the walls 398 and 400 respectively, effecting the necessary seal to prevent air leakage around the

member 392. Again, the operation of the gauge in both the reading and inflating modes is identical to that previously despribed with respect to figure 27 and 28. Referring to Figure 32, there is depicted yet another design which implements the principles of the subject invention. The device as shown includes, first of all, housing means 10 which form a first en¬ closure. The housing means 10 comprises* a lower housing portion 12 which, preferably, is fabricated from an opaque plastic or similar material. The lower hous¬ ing in the preferred embodiment shown is, typically, cylindrical in shape. It includes a lower end 14 v/hich has an internal thread 16, enabling the gauge to be ^• screwed on to a tire valve stem. The lower housing 12, includes an outer cylindrical wall 18 which extends approximately 1/2 the length of the overall gauge. In¬ ternal to the cylindrical wall 18 and coaxial with the longitudinal axis of the gauge is an inner cylindrical wall, 20. The inner cylindrical wall is connected to the outer cylindrical wall by a cylindrical disc-like section 22, which lies in a plane perpendicular to the longitudinal axis of the gauge. This disc-like portion includes a plurality of cylindrical, inlet ports 24 which run parallel to the longitudinal axis of the gauge. The inlet ports 24 provide a means whereby the chamber 26, defined by the lower end 14 of the housing 12 and the cylindrical disc 22, communicates with the annular chamber 28 formed above the cylindrical disc 22, between the inner cylindrical wall 20 and the outer cylindrical wall 18.

Sandwiched between the internal thread 16 and the under side of cylindrical disc is a standard "O-ring" 30 constructed from an elastomeric material such as rubber.

Additionally, integral with an protruding from the bottom side of the cylindrical disc 22 in an axial

direction, is a knife-like annular edge, 32.

The upper end 34 of the inner cylindrical wall 20 is formed in a U-shaped fashion. Similarly, the out¬ er cylindrical wall includes a U-shape ridge 36, internal of the wall 18 v/hich also extends the full perimeter of the wall 18.

The first enclosure means, _^ 10, also includes ah upper housing 40 which is of the same general cylin¬ drical shape as the lower housing 12. Whereas the lower housing can be made of an opaque plastic material for reasons soon to become obvious, the upper housing 40. is made, of a transparent plastic material. Embossed on the outer surface of the upper housing, is a suitable arrangement of numbers 42 in figure 34 positioned sequen- tially along the axial length of the upper housing wall beginning v/ith the lower number tov/ards the bottom of the gauge, as viewed in Figure 34, ascending to a higher number at the top of the gauge. These numbers represent the pressure range of a gauge given its particular appli- cation - e.g. when used to measure tire pressure the range would be that shown in Figure 34. To improve the visibility aspect of the pressure gauge of this invention these numerals ^• are displayed in identical groupings, spaced 120° apart, about the perimeter of the upper housing wall. Another arrangement of numbers can be seen located at 43 in figure 34.

Interposed between each grouping of numerals just described, at 120° spacing, are three groups of axially positioned serrations 44. These cooperate with another "O-ring" 46 and the indicating band 48, v/hose ^• function and location are described later on to provide a ready indication of the deviations of the tire pressure from the previously set level.

The upper housing 40 includes an outer cylin- drical wall 50 which has an outside diameter virtually the same as the inside diameter of outer cylindrical wall 18 of the lower housing 12. When finally assembled

the outer wall 50 nests within the outer wall 18. The bottom end of the outer cylindrical v/all 50 "as viewed in Figure 33, is U-shaped and together v/ith the U-shaped ridge 36 forms substantially, a circular groove into v/hich the diaphragm ring 54 is positioned as soon to be described.

Coaxial v/ith the outer cylindrical vall 50 and extending, axially, approximately the same length as the outer v/all 15 is an inner cylindrical vall* 56. Both walls are connected to each other by a disc like member 58 which lies in a plane substantially perpendicular to the longitudinal axis of the gauge and v/hich, again, is integral both v/ith the outer cylindrical v/all 50 and the inner cylindrical v/all 56. The inner- cylindrical v/all 56 also includes at its bottom end, a U-shaped ridge 60 v/hich extends the perimeter of the ^" inner cylindrical wall 56 and v/hich, together with the ridge formed at the upper end 34 of the inner cylindrical v/all 20 provides a circular groove into which the inner ring 62 of the previously mentioned diaphragm is positioned. Both inner walls, 20 and 56, are hollow so that v/hen they are aligned in final assembly they form a cylindrical passageway 65, which runs the length of the gauge, connecting chamber 26 to chamber 71, the latter being formed as described below.

An annular chamber 64 is formed betv/een the outer wall 50 and the inner wall 56. Communicating between this annular chamber 64 and the environment outside the gauge, for reasons soon to become obvious, there exists a vent hole 66 v/hich passes through the disc-like member 58.

Extending axially upward from the disc-like member 58 is a cylindrical protrusion 68 which is. adapted in a known fashion to fit a pump inflating hose. The protrusion, 68, forms a third annular chamber 71. The protrusion 68 is threaded to accept a standard protective

_J U EA75

OMPI

cup (not shown) .

When completely assembled there is interposed between the U-shaped ridges of the inner and outer walls 5 20 and 18 of the lower housing 12 and the inner and outer walls 56 and 50, respectively, of the- upper housing 40, a diaphragm assembly 70 made of a highly flexible, low friction material such as rubber,. It includes an inner ring" section 62, sandwiched between opposing U-shaped

10 ridge in the inner walls 56 and 20 and an outer ring 54 interposed betv/een the U-shaped ridges of outer wall 50 _, and ridge 36. The diaphragm rings are inter-connected by an annular piece of flexible rubber material which for purposes of the particular configuration illustrated ^" 15 in Figure 32, is essentially U-shaped. When finally assembled, rings 54 and 62 are bonded to the ridge sec¬ tions of the inner and outer walls of both housings. This insures an airtight enclosure into which the pressur¬ ized air within the tire is released.

20 As part of the gauge, means are provided for releasing the pressurized air in the tire into the gauge. Further the releasing means is adapted to provide for inflating the tire when the gauge indicates that the pressure has dropped below a-desired minimum. The

25 pressure releasing means preferably includes a steel cylindrical shaft 72 which extends the length of the gauge and which is located at the axial center of the gauge within the passageway 65 formed by the inner v/all 20 and the inner wall 56. The shaft 72 terminates in a

30 flange 74 at the lower end 14 of the gauge. The flange lies in a plane perpendicular to the axis of the shaft 72, and includes an annular recess into v/hich is placed a sealing gasket 76 v/hich cooperates with knife edge 32 to form a seal for purposes soon to be described. Press

35 fitted onto the opposite end of the shaft 72 is a bushing 78 generally made of steel.

Positioned substantially in the upper annular

O

, A

chamber 64 is located means, 80, for both controlling the variation of the volume of annular chamber 28 and for giving to the observer an indication of the pressure in the tire.

In the embodiment described means 80 includes a piston like member 82 of cylindrical shape which has an outside diameter substantially, equal to the inside diameter of the outer wall 50. The piston member is made of a smooth, plastic-like material v/hich minimizes ^* fric¬ tion betv/een the surfaces, enhancing the sensitivity and accuracy of the gauge.

The piston like member 82 includes an axially extending cylindrical wall 84 v/hich barely contacts ^• the inner surface of outer wall 50 and a section 86, integral v/ith the cylindrical wall portion 84 and perpendicular thereto. The inner axially extending surface 83 of the horizontal section is in substantial contact v/ith the outer surface of inner v/all 56. The underside 88, of the horizontal section 86 has generally, a U-shaped con¬ figuration. The inner and outer extremities, 90 and 92 respectively, of the U-shaped underside are contoured to take the shape of the inner and outer diaphragm rings 62 and 54 respectively. This provides an "airtight" seal in a manner soon to be described if and v/hen the diaphragm 70 ruptures. The arcuate contour of the extremities 90 and 92 is better seen in Figures 36 and 37.

Cylindrically shaped piston member 82 defines a cavity 94 between the inside surface of wall 84 and the outside surface of v/all 56. Nested in this cavity and extending the axial length of the gauge between hori¬ zontal section 86 and disc like member 58 is a callibrated coil spring, 96. Spring 96 is preferably made from a suitable spring steel selected to have the necessary spring constant to counteract the force exerted on the piston like member 82 by the pressurized gas in chamber 28 acting through diaphragm 70.

Depicted in Figure 32 is a cylindrical, cup-*- shaped, covering device 98 of suitable opaque material, such as plastic which hides ^' the "exposed" end of the spring 96 for the purpose of enhancing the appearance of the gauge. Where employed, the covering device includes a vent hole 99 to enable air otherwise under compression in chamber 94, to escape.

The indicating feature of means 80 is provided, in combination, by an annular colored band 48 which pre¬ ferably is painted in a suitable annular recess in cylin¬ drical v/all 84. This insures that the band is not rubbed from the outer surface of the cylindrical wall 84 due to the constant axial movement of the piston member 82 with¬ in the chamber 64 when the gauge is in place. ASSEMBLY

The unit is assembled by first positioning the opaque cover 98 in the upper housing portion 40. The coil spring 96 is next placed within the cover 98 followed by the piston member 82.

The diaphragm is positioned in the lower housing such that rings 54 and 62 rest in grooves 36 and 34 re- ^* spectivfily. The rings 54 and 62 are secured thereto by a suitable bonding material.

The outer wall 18 and the lower housing 12 are then either slipped over the outer cylindrical wall 50 of the upper housing 40 and bonded thereto or, alternately, it is threaded onto the upper housing with suitable bond¬ ing cement calking the threads to insure an airtight seal between the contacting surfaces of the tv/o outer walls. Prior to mating the upper and lov/er housings, bonding material is added to ridges 52 and 60 to thereby provide an airtight seal between those surfaces and the top por¬ tion of diaphragm rings 54 and 62.

The means for releasing or suppling air to the tire is next positioned in the gauge. The flange-shaft unit 74-72 is inserted in the passageway 65. The steel

bushing 78 is then press fitted over the top end of the shaft 72 thereby retaining the latter in place in the gauge. As can be best appreciated from figure 36, al- though not depicted therein, a coiled spring member can be interposed between ^' the ^* bottom of the bushing 78 and the top of the disc like member 58 within the chamber 71 to minimize any rattling of the shaft when the gauge is disconnected from the tire stem, and improve the seal between gasket 76 and edge 32.

Figures 36 and 37, are useful 'in understanding the operation of the gauge. The gauge is screv/ed on to the tire valve stem 100 until the top of the valve stem 102 contacts the O-ring 30, compressing it as shown. Considering the design of the standard tire valve stem, the height of he flange member 74 of the gauge is such that when the gauge is threaded on the standard valve stem 100 the underside 104 of the flange 74 contacts the valve actuating rod 106 depressing it a sufficient amount, typically on the order of .025 to .032 inches, to enable a sampling of the pressurized gas within the tire to enter the annular chamber 28 through inlet ports 24.

The pressurized gas contacts the diaphragm 70 forcing it upward as viewed in Figure 36 and eventually to the point v/here is assumes the contour as depicted in Figure 36 v/hich includes conforming itself to the U-shaped underside section 88 of piston 82. The piston member 82 is forced upward in response to the pressure exerted by the gas through the diaphragm 70. Coil spring 96 as a consequence is compressed betv/een the section 86 and the disc like end cap 58. Because the diaphragm 70 forms an ^• airtight barrier between chambers 28 and 64, the air in compression in chamber 64 is forced out of chamber 64 through vents 99 and 66. As noted earlier the spring constant for spring 96 is chosen so that the force exerted D the spring in opposition to the force exerted by the pressurized gas on the piston like member 82, is such

that when the annular band 48 is opposite the appropriate pressure reading on the numerical display 42, the spring force exactly balances the force exerted by the pressur- 5 ized gas.

If it is desired to further inflate the tire, an air pump hose 108, as shown in Figure 37, may be presse on to the protrusion 68. The valve stem rod 110 positione in the head of the pump hose 108 contacts the bushing 78. _Q The bushing 78 is depressed and in turn forces a down¬ ward movement of shaft 72 and flange 74. The sealed forme betv/een gasket 76 and the knife-like annular ridge 32 is "broken" enabling pressurized gas supplied from a compre- sor (not shown) to pass along the length of the gauge 5 through the passageway 65 past ridge 32 and into the valve stem 100 located on the device to be inflated. The axial length of the bushing 78 is such that the bottom side of bushing 78 as viewed in Figure 37 will not contact the top of the disc like member 58 when the inflating hose 108 is in place. This insures that the seal formed betv/een the gasket 76 and the knife-like ridge 32 is "broken", enabling the tire to be inflated.

As the pressure of the gas in the inflated de¬ vice increases the piston member 82 rises further in cham- ber 64, The person inflating the device will remove the inflating hose 108 v/hen the annular band 48 has reached the desired pressure level. At this time the operator would remove the hose 108 and slip O-ring 46 to a new position on the gauge opposite the band 48. A convenient reference is established which subsequently enables the operator to determine whether or not the tire has lost . pressure.

Alternately, it may be desirable to release a certain amount of pressurized gas from the tire. In this case, the operator would depress the shaft 72 by pressing down on the bushing 73, thus breaking the seal betv/een the gasket 76 and the edge 32. ^' Downward movement of the

shaft will cause the valve actuating rod 106 to further depress resulting in the venting of pressurized gas from the tire, via the passageway 65 _* The bushing is kept depressed until the annular band drops to a portion oppo¬ site the desired pressure.'

Figures 38 and 39 depict in a partial, sec- tional view, air improved version of the underside sur¬ face of the piston member 82 which is employed where it is important to have a more sensitive gauge. The improve¬ ment calls for providing a cylindrical appendage 112, end¬ ing axially from section 86. The cylindrical appendage improves the sensitivity and thus the accuracy of the gauge by reducing the frictional forces occurring between the surface of the diaphragm and the walls which the dia¬ phragm contacts, viz., the inner surface of v/all 50 and the outer surface of v/all 56. Vfliereas in the previous^ discussed U-shaped design, the counter-acting force ex¬ erted on the piston member 82 by the spring 6 had to overcome a shearing or frictional force at the interface between the diaphragm and the two cylindrical* walls as v/ell as compressive forces in the diaphragm, the improve- ent of Figure 38 need only overcome a relatively low adhesive force between the diaphragm and the wall. In effect the diaphragm is "peeled" from the tv/o v/all sur¬ faces. Thus the calculations determinative of the spring constant can assume, more correctly, "zero" frictional forces with the result that a more sensitive and accurate gauge is developed. Figure 39 illustrates an aspect of the inven¬ tion, common to the design previously described, i.e., ^• Figures 32, 36 and 37, but which is better pictorialized ^' in Figure 39. This feature might be called a "fail safe" capability. In effect, this "fail safe" capability pre- vents the gauge from becoming a device for deflating the tire when the former malfunctions, particularly through rupture of the diaphragm 70. The possibility of

diaphragm rupture is a practical consideration after the gauge has been utilized for extended periods of time. This is due in part to the continual up-down movement of the piston in response to pressure fluctuations in the tire. This pressure fluctuation is a continuing thing due in part to the rough road conditions to which the tire may be subjected, the increase in pressure due to tire heating and similar other disturbances. A ruptured condition is demonstrated in Figure 39 by opening 114. Absent the "fail safe" design the air passing from the chamber 28 through opening114 would pass betv/een the sid of the piston 82 and the wall 50. However, when the dia phragm ruptures causing a reduction in the force support ing the piston 82 in an elevated position, spring 96 forces the piston 82 downward as viewed in Figure 39 until the inner and outer extremities SO and 92 of the underside of the piston contact the diaphragm rings 62 and 54 respectively. Sufficient contact area is provide betv/een the rings and the contacting portion of the grooved extremities so that the piston 82 is prevented from 3_ιγ further downward movement. At worst, the pre- sure in the tire is reduced to an amount such that the force exerted on the piston 82 by the remaining pres- surized gas is just balanced by the spring force exerted by spring 96 at the point of contact betv/een the grooved extremities and the diaphragm rings. Further deflation is prevented.

The person inflating the tire can detect the fact that the diaphragm in the gauge is ruptured v/hen he goes to inflate the tire. The tire would expand in ^• response to the increasing air pressure but the gauge wi fail to respond due to the exiting of the gas through th ruptured diaphragm. Also the piston 82 would rise up ever so slightly causing a passing of the air through the vent hole 66 giving use to a hissing sound. Noting this, the operator knows he has a defective gauge.

^"

Figures 40, 41 and 42 are particular variations of this latter discussed design where alternate means for forming the airtight enclosure of variable volume are de- pioted. For the purposes of discussion v/ith regard to figures 40, 41 and 42, the means for releasing the pres¬ surized gas from the inflated tire, viz., the shaft-flange- bushiiig arrangement, 72, 74 and 78 respectively, will not be discussed. Suffice* it to say that the operation of this aspect of the _. particular embodiments of Figures 40, 41 and 42 is essentially identical to ^' that previously described.

Referring to Figure 40, the chamber 26 vents through inlet ports 24 ^' into a air-tight volume 28 of variable volume which is maintained air-tight by tv/o 0- rings one 16 and one 18 which form a suitable airtight seal betv/een piston 120 and housing walls 122 and 124. The overall design of the embodiment of Figure 40 as far as the housing construction is concerned is somewhat sim- plified in that a gauge consists of a basic cylindrical housing 126 of clear plastic v/ith an end cap 128 either bonded or threaded into the cylindrical opening at the top 130 of the gauge.

Tv/o additional 0-rings 138 and 140 are position- ed in the bottom of the chamber 28, each of the 0-rings having a diameter substantially equal to the diameter of housing walls 124 and 122, respectively. V/hen the 0- ings 116 and/or 118 wear to a point that they no longer provide an airtight seal between the piston 120 and the surfaces of the housing walls 122 and 124, the spring 96 will force the piston downward as viewed in Figure 40 until the chambered edges 134 and 136 contact the 0-rings 138 and 140 respectively. Through this technique, the "fail safe" capability described in the earlier embodiment is provided in this configuration.

Suitable pressure indicia would be located on the outer surface of wall 122 as well as serrations for

locating the O-ring 46. The indicating aspect of the gauge is essentially the same as that previously des¬ cribed. Figure 41 discloses an embodiment v/herein the chamber of variable volume 28 is formed by an annularly shaped bellov/s, 142. One end of the bellows 142 is bonded to the bottom of the chamber 44 such that it en¬ compasses the inlet ports 24, thus providing an airtight ^' enclosure. The opposite end 146 of the bellov/s is "cappe off" by a lightweight plastic, disc-like member 148, which is bonded in place to the end 146 of the bellows. The disc like member 148 would have the indicator band 48 annularly disposed about its perimeter with corres- ponding pressure markings again positioned axially along the outer surface of the housing wall. The housing con¬ struction is similar to that shown in Figure 40.v/ith the exception that the venting hole 66 is not required. This is so because of sufficient clearance between the member 148 and the inside walls of the housing. In this configuration provided the seam 150 betv/een the end cap 152 and inner cylindrical housing 154 is bonded, there is no need for the "fail safe" additions of the previously discussed designs. Figure 42 shows yet another embodiment where the airtight folume is provided by a flexible, helically- shaped, hollow tube 156 which communicates with chamber 26 through port 158. In this configuration upon release of the pressurized gas of the inflated tire, the gas enters the helical coil 156 at end 157 which is bonded to the inner surface 160 of the bottom portion 162 of the housing 164. The coil in response thereto extends itself in an axially upward direction as viewed in Figure 42 much in the manner of the v/ell known Bourdon tube. This conversion of pressure to axial displace¬ ment is transmitted to piston member 166 which is made of opaque plastic and v/hich includes the familiar

'BU

indicator band 48. The design of the tube and the spring constant of the spring 96 are selected so that the annu¬ lar band 48 is positioned opposite the corresponding 5 pressure indication on the surface of the housing 164. Again, as was the case v/ith the device of Figure 41, there is no requirement for a vent hole such as that shown at 66 in Figure 32 and 40. _. Because of the* con¬ struction of the flexible tube 156, which typically could o be a lightweight plastic or metal the device is inher¬ ently "fail safe" so as to preclude the necessity of pro¬ viding a scheme similar to that incorporated in the pre¬ viously described embodiments. In this design the heli¬ cal coil is wound around the center stem conserving 5 axial length.

In another variation of this design, the coil itself is calibrated such that its axial movement is pro¬ portional to the air pressure within. This eliminates the need for spring 96, further simplifying the design. 0 Finally, another variation of the embodiment of Figure 32 is shown in Figures 43 and 44. The basic design of Figure 32 is incorporated in this embodiment which is intended to be supplied as part of the original tire when delivered by the tire manufacturer or new car 5 dealer. The main difference betv/een the design of Figures 43 and 44, and those previously described, is the require-* ment that a coil spring 170 be disposed betv/een the bush¬ ing 78 and the top side of disc like member 58. This spring, 170, in effect replaces or serves the same func- 0 tion as the spring formally found in the tire valve stem. Spring 170 exerts a sufficient upward pressure as viewed in Figure 43 to maintain a sufficient seal between the gasket 76 and the knife edge 32 to prevent leakage from the gauge at that point. 5 As shown, the outside surface of outer wall 18 is bonded to a rubberized, tire valve structure 172 which is secured in the tire side v/all 174 i _{n a} lαiown manner.

UREATT

__0MPI__

The tire would be inflated in the same manner as des¬ cribed earlier.

Figures 43 and 44 show a modification of the design previously described which may be a desirable adaptation of the basic design. It includes the pro¬ visioning of a filler tube 176 which is bonded, in place in the vent hole 66. The filler tube 176 would be fabri¬ cated from copper or similar material v/hich could be readily cut and then crimped or soldered to provide an airtight termination as shown in Figure 44 at' 178.

Employing this variation, the gauge manufac¬ turer would be able to preset a given lot of gauges for use at a particular pressure - the one most suitable for a given tire. A range of these type gauges would be provided v/hich covered existing and anticipated recom¬ mended pressures as set by -the tire manufacturers. uring the manufacturer of the gauge and after it is assembled, the gauge v/ould be positioned on a suit- able tire simulating device which could be inflated to the desired pressure for that gauge. Initially, piston 180 would be forced upward until the top thereof, 182, contacted the underside, 184, of the end cover. (Spring 186 in this application would not be the calibrated type disclosed earlier. Its main function in this applica¬ tion would be to insure that the piston 180 is thrust downward if the diaphragm ruptures to give an indica¬ tion that the gauge has failed) .

After inflating the tire simulating device, pressurized gas would be introduced into chamber 64 through filler tube 176. The gas in chamber 64 would exert a downward force on piston 180. The piston v/ould move down and the pressure of the gas supplied through filler tube 176 would be varied until the piston assumed an intermediate axial position. The annular band 48, of course, would position itself in a corresponding axial position. A permanent annular, masking bank 196 v/ould

- ^" B __

then be painted on or otherwise permanently affixed to the outer surface of housing 198 at the same axial loca¬ tion as the band 48. . The filler tube 176 would be crimped and/or soldered or sealed in some other suitable way to prevent the pressurized gas from escaping from chamber 64. The gauge could then be removed from the simulating device and prepared for delivery. The gauge just described v/ould be delivered to tire suppliers or others whose 30b it is to mount tires. .The gauge would be supplied with instruc¬ tions which would note its particular operating pressure. The supplier would install the gauge-valve device in a tire whose recommended pressure would be that of the gauge. The tire v/ould then be inflated until the annular band 48 positioned itself behind the masking band 196. At this point, the supplier would know that the tire is inflated at the correct pressure for that tire.

Subsequently, the motor vehicle operator could tell If the tire was not at the right pressure by noting that band 48 was no longer positioned at the same axial position as ^" indicator band 196. He could then take the necessary corrective action in order to re-establish the proper operating pressure.

The approach just described as noted earlier eliminates the need for a calibrated spring and thus pro¬ vides a less costlier gauge. Further, motor vehicle operators with no idea of the right pressure required by their tires need only know to align the bands 48 and 196 to achieve the proper pressure and thus insure pro- per operating conditions.

It is to be noted in the embodiment depicted in Figure 43, that the previously described means for inflating the tire-bushing, shaft and flanges 78, 72 and 76 respectively, could be replaced by a standard valve stem v/hich v/ould be fitted in the disc like end 58 in a suitable fashion.

Other variations of the specific constructions

disclosed will be apparent to those skilled in the art and must be considered to be v/ithin the breadth of the invention as defined in the appended claims .

-BU

.A.