CA1096761A - Pressure gauge - Google Patents

Abstract

ABSTRACT
This invention describes a pressure gauge which in one em-bodiment is adapted to be continuously mounted on the valve stem of the inflated device, thereby providing a continuous indication of the pressure therein It includes an airtight enclosure formed by an expandable means such as a diaphragm, positioned within an outer housing The gauge is adapted to contact the standard valve stem in the inflated device to release pressurized gas from the device into the airtight enclosure In response thereto, the air-tight enclosure expands Cooperating with this expansion of the airtight enclosure is a piston like member which includes means for controlling the expansion of the airtight enclosure The con-trol means is calibrated so that the piston like member moves an axial distance in an amount proportional to the pressure of the gas in the tube The piston has an indicator band painted thereon which positions itself opposite appropriate psi markings on the outside of the housing This provides a ready indication of the pressure The means for releasing the pressure into the expand-able, airtight enclosure is further adapted to enable additional pressurized gas to be introduced into the inflated device The expandable enclosure is adapted to insure an airtight seal within the gauge if the diaphragm should rupture for any reason. Other embodiments of the basic invention describe alternate approaches to providing the expandable airtight enclosure including expand-able bellows, a hollow flexible tube or a scheme wherein the space between the piston member and the outer housing is sealed by suit-ably positioned O-rings. Still other embodiments describe a pas-sive gauge which must be depressed by the operator's thumb to function but which also provide means for supplying pressurized gas to the inflatable device while the gauge is in place. These embodiments provide a doubling back of the airtight enclosure re-ducing the overall height of the gauge.

Description

i~6761

2 BACKGROUND OF THE INVENTION

3 Field of the Invention

4 This invention is directed to pressure gauges generally, but more particularly to a pressure gauge which can 6 be screwed on to a valve stem or contilluously mountcd tllcrcto.

8 Maintenance of gas pressure within an inflated device 9 is a desirable effect particularly in tires used on motor vehicles. Through maintenance of proper tire pressure levels, 11 the operator of the vehicle is assured of an optimum situation 12 with regard to tire wear and good gas mileage, and conse~uently 13 therefore, is further assured of operating his vehicle in a 14 safer condition. An added benefit of improved tire wear and gas mileage through proper inflation is a reduction in the demand on 16 our precious oil reserves - a fact of major significance in this 17 day of energy conservation consciousness.

18 The need for maintenance of correct tire yressure 19 prompted the development of a host of various tirc pressure gauges with their peculiar advantages and disadvantages. All of 21 us are familiar with the gauge associated with the tire pump 22 found at the local gas station. The desired pressure is first 23 located on the pump meter by a rather crude needle-indicator 24 scheme and then the air hose is applied to the tire. The pump then forces air into the tire until the pressure therein 26 counterbalances the pressure of the air supply for the 27 particular setting. Recognizing the inaccuracies of such a 28 coarse approach, the hand-held gauge was developed. The gas 29 station attendant would place the gauge on the tire valve stem, 1. ~

note the pressure, add air to the tire with the station pump, 2 recheck the pressure, etc. Quite frequently the operator would 3 repeat this operation three or four times for each tire before 4 arriving at the correct level.

In response to the desirability of continuous 6 monitoring of the tire pressure in these situations, attachable 7 or direct mounted gauges were developed. These, typically, 8 provide for a continuous monitoring of the tire pressure but, 9 with the exception of a few devices recently developed, they preclude the inflating of the tire when required without first 11 removing the gauge from the valve stem. More recently, however, 12 gauges- have been developed which are directly mounted to the 13 tire and which also allow for the pressurization of the tire 14 while it is in place. Such gauges are described in U.S. patent Nos. 3,451,418 and 3,592,218.

16 The particular device described in the former patent, 17 however, is a rather complex apparatus. This can be concluded 18 from a casual glance at the various Figures of the drawings. In 19 particular, from a detailed reading of the patent, the mcchanism for preventing leakage from the inflated tire upon a malfunction 21 of any part of the tire gauge, involves a complex spring -22 "operating member" arrangement, items 45 and 26 respectively in 23 Figure 2, which typifies the overall complexity of the gauge.

24 The device described in the '218 patent, reauires the operator to hold the body of the gauge with his thumb and 26 forefinger, twist it and then observe the extended gauge portion 27 which protrudes into the cup formed by his hand such that it is 28 partially obscured thereby. Further, this gauge is inordinately ~6761 1 long. Lastly, when one is filling a tire through such a gauge, 2 the operator is required to remove the air hose, grasp the body 3 as above, note the pressure, reapply the air hose, etc., until 4 the desired pressure is achieved - a relatively lengthy process.

It is a primary object of this invention to provide a 6 pressure gauge which in line with the simplicity of the overall 7 gauge, provides a simple means for inflating the inflatable 8 device when the gauge is in place and which includes means for 9 sensing the pressure of the device without removing the gauge.

It is an object of one adaptation of this invention to 11 provide a pressure gauge for an inflatable device which is 12 detachably mounted to the device and which is simple in 13 construction and consequently, inexpensive to fabricate.

14 It is an object of one adaptation of this invention to provide a simple means for "sealing" the gauge upon rupture of 16 its elastomeric part, thereby preventing further leakage from 17 the inflated device.

18 It is another object of one adaptation of this 19 invention to provide a gauge which continually monitors the pressure of the tire and which allows the operator of the 21 vehicle to tell from afar, whether or not the device pressure 22 has deviated from a previously set pressure.

23 It is a primary object of still yet another adaptation 24 of the invention hereof which provides for the doubling back of the pressure monitoring portion of the gauge to reduce its 26 length, thus avoiding interference problems.

27 It is a further object of the adaptation of this 28 invention which includes the doubling back feature, to provide a 29 gauge which utilizes standard valve and other related parts, for simplicity of design and economy of manufacture.

'~t~ ; 3.

~6761 1 SUMMARY OF TH~ INVENTION
I
2 The invention claimed herein pertains to a gauge for 3 measuring the pressure of an inflatable device. The gauge 4 includes a valve stem assembly centrally disposed within the gauge and means for forming a first enclosure, which is 6 concentrically disposed outwardly of the valve stem. Mcalls 7 forming a second enclosure of variable volume within the first 8 enclosure are provided for affixing the gauge to the inflatable 9 device. The gauge also has first channel means for directing gas released from within the inflatable device via the valve 11 stem axially away from the inflatable device. Second channel 12 means, communicating with the first channel means, are provided 13 for directing the released gas radially outward from the first 14 channel means and into the second enclosure, the second enclosure increasing in volume in an axial direction toward the 16 inflatable device for increasing gas pressure. Means are 17 provided for controlling the variation of the volume of the 18 second enclosure such that the variation is proportional to the 19 pressure of the gas, and means are provided for indicating the variation in response to the pressurized gas to thereby give a 21 measure of the pressure of the gas.

22 More particularly there is described a pressure 23 gauge for measuring the pressure of an inflatable 24 device which comprises means defining a first enclosure including, in part, a transparent section upon which 26 is located in predetermined axial location along the 27 body of the first enclosure, psi indicia which lQ467~
1 correspond to the anticipated range of pressure within the 2 inflated device. Internal to the first enclosure means is an 3 expandable, diaphragm-like material which is bonded in a 4 suitable fashion to the first enclosure to thereby form an "airtight" secondary enclosure internal to the first. Inlet 6 ports in the first enclosure allow for entry of pressurized gas 7 from the inflatable device into the airtight enclosure internal 8 to the gauge. Positioned on the longitudinal axis of the gauge 9 is a shaft-like member, including a flanged end adapted to operate the valve in the valve stem of the inflatable device, 11 when the gauge is in place on the valve stem, to thereby release 12 the pressurized gas from the inflatable device illtO the inlet 13 ports as previously mentioned. The shaft extends the length of 14 the gauge and has positioned on the end opposite the flange end, a bushing. The axial length of the bushing is such that when 16 inflating means such as an air pump is applied to the bushing 17 end of the gauge, the shaft or rather the bushing cooperating 18 with the in1ating pump moves the shaft axially towards the 19 inflatable device. This enables the higher pressure gas in the inflating means to run the length of the gauge and enter the 21 inflatable device. Returning to the monitoring aspect of the 22 gauge of this invention, when the pressurized gas is released 23 into the airtight enclosure, the elastomeric diaphragm expands 24 in response thereto. It is "thrown" against a piston-like member axially positioned outward of the diaphragm. Normally, 10~6761 1 the piston would respond uncontrollably, to the force e~erted 2 thereon through the diaphragm by the pressurized gas but the 3 latter force in this case is counteracted by a calibrated spring 4 means which resists the actual movement of the piston in a predictable fashion. The piston, consequently, moves in a 6 proportional relationship to the pressure of the gas in the 7 inflatable device. The piston is suitably marked, for example, 8 with a colored circumferential band which is located at a 9 prescribed position along its axial length. Its location is coordinated with the previously mentioned indicia on the first 11 enclosure forming means such that it aligns itself with the 12 appropriate number signifying the pressure of the gas then 13 internal to the inflatable device.

14 The piston, spring and diaphragm are designed such that they cooperate with each other by sealing off the airtight 16 enclosure, if the diaphragm ruptures, thereby preventing leakage 17 of the pressurized gas to the "outside world" through the gauge.

18 Alternate embodiments of the invention call for 19 replacing the diaphragm as described above with a hollow flexible tube or bellows or an "O-ring"-sealed, piston 21 arrangement, all of which implement the basic principles of the 22 invention.

23 Still another embodiment provides for use of the basic 24 gauge described above as originally supplied equipment incorporated with the inflatable device, such as a tire, when 1~6761 1 the tire is first supplied by the manufacturer. I
.!
2 Still other embodiments described provide for the 3 doubling back of the airtight enclosure on the barrel of the 4 gauge. These embodiments include a design which is affixed to a standard valve stem as the latter is already in place on a tire 6 rim. A second design of this embodiment includes a standard 7 valve core assembly as part of the gauge itself with the 8 composite inserted in a tire rim as a single gauge-valve unit.
9 In both of these designs, air is released into the gauge proper only when the pressure reading stem is actuated, as opposed to 11 the continuous monitoring feature of the aforementioned 12 embodiments. The released air is directed axially away from the 13 valve stem initially by a first channel, and into a second 14 channel, disposed transversely to the first channel. The latter directs the air radially outward from said first channel and 16 into an airtight enclosure of variable volume. The latter is 17 formed by a piston-like member disposed in a cylindrically 18 shaped enclosure positioned concentrically out~ard of the valve 19 stem. It increases in volume in response to increasing gas pressure, in an axial direction, toward the inflatable device.

21 In the gauge-valve design, the valve core assembly is 22 removable using presently available tools and standard 23 procedures.

24 These and other aspects and advantages of the invention will become more ~ 6(a).
":s, i~G761 1. apparent from the following detailed description and appended 2. claims taken in conjunction with the accompanying drawings in 3. which:
4. Figure 1 is an elevational view of the basic invention.

5. Figure 2 is an end view of the gauge as shown in figure 3 as

6. viewed in the direction of lines marked 2-2.

7. Figure 3 is a perspective view of the gauge of figure 1.

8. ' Figure 4 is an end view taken of the gauge of figure 3 as

9. viewed in the direction of lines 4-4.

10. Figure 5 is an elevational view of the gauge of fig ~ 1 sh~n in

11. place on an inflatable device.

12. Figure 6 is an elevational view in section showing the gauge

13. of figure 1 in cooperation with gas pumping means to inflate the

14. inflatable device.

15. Figures 7 and 8 depict an improvement in one aspect of the

16. invention of figure 1.

17. Figures 9, 10 and 11 shown in elevational, sectional views,

18. alternate embodiments of the subject invention.

19. Figures 12 and 13 show in elevational, sectional views, an

20. application of the basic invention in situations wherein the gauge

21. is supplied as part of the original equipment.

22. Figure 14 is a perspective view of yet another embodiment of

23. the subject invention.

24. Figure 15 is a cross-sectional, elevational view taken along

25. lines 15-15 of figure 14.

26. Figure 16 is a cross-sectional view taken along lines 16-16

27. of figure 15.

28. Figure 17 is a cross-sectional view taken along lines 17-17

29. of figure 15.

30. Figure 18 is a cross-sectional view taken along lines 18-18

31. of figure 15.

32. Figure 19 is an elevational view of the gauge of figure 15

33. being used in one mode of operation.

34. Figure 20 is an elevational view of the gauge of figure 15

35. being used in a second mode of operation.

36. Figure 21 is an elevational view of a variation, in part,

37. of the gauge of figure 15.

6(b) - 1~"6761 ~¦ Figure 22 is an eleva~ional view o~ a varia~ian, in par~, a~ the galJge af figure 15.
2 Figure 23 is an elevational view of a variation, in part, of the gauge of figure 15.
3 Figure 24 is an elevational vlew of still another embodiment of the sub ject inventio .
4 Figure 25 is a partial, cross-sectional, elevational view of the embodiment of figure 24.
6 Figure 26 is a cross-sectional, elevational view of a part of the embodiment of 7 figure 24.
8 Figure 27 is a plan view taken along lines 27-27 in figure 26.
9 Figure 28 is a perspective view of a standard valve core assembly.
~1) Figure 29 is a cross-sectional, elevational view of the embodiment of figure 24 11 being used in the reading mode.
1~ Figure 30 is a cross-sectional, elevational view of the embodiment of figure 24 13 being used in the inflating mode.
14 Figure 31 is a cross-sectional, elevational view of a modified version of the embodiment of figure 24.
16 j Figure 32 is a partial, cross-sectional view of one type of seal which can be used 17 in the embodiment of figure 24, àppearing with Figures 26, 27 and 28.
18 Figures 33, 34 and 35 are elevational views of various adaptations of the embodi-19 ment of figure 24, Figures 34 and 35 appearing with Figures 29 and 3û.
2~ Figure 36 is an elevational view of still another embodiment of the invention.
21 Figure 37 is a plan view taken along lines 37-37 in figure 36.
22 Figure 38 is a perspective view of the seal employed in the embodiment of 23 figure 36.
24 ¦ Figure 39 is a perspective, sectional view taken along lines 39-39 in figure 38.
Figures 40 and 41 are partial, sectional views of an aspect of the design of the -26 ¦ embodiment of figure 36.
27 ¦ Figures 42, 43 and 44 are various alternative caps which can be employed with 2~3 j thc various embodiments depicted.
29 ¦ DESCRIPTION OF THE PREFERRED EMBODIMENT

i -6(c)~

1. In ~he following discus1on It w711fibe assumed tba~ the device ta be inflated is 2. 1~ the automo ile tire. This certainly is nat ta be canstrued as a limitatian an the versatility ~ ic~ el~

//

30.
-6(d)-1~1 1 Referring to Figure 1, there is depicted a hasic 2 design which implements the principles of the subject invention.
3 The device as shown includes, first of all, housing means 10 which 4 form a first enclosure. The housing means 10 comprises a lower housing portion 12 which preferably, is fabricated from an opaque 6 plastic or similar material. Th~ lower housing in the preferred 7 embodiment shown is, typically, cylindrical in shape. It includes 8 a lower end 14 which has an internal thread 16, enabling the gauge g to be screwed on to a tire valve stem. The lower housing 12, includes an outer cylindrical wall 18 which extends approximately 11 1/2 the length of the overall gauge. Internal to the cylindrical 12 wall 18 and coaxial with the longitudinal axis of the gauge is an 13 inner cylindrical wall,20. The inner cylindrical wall is connect- -14 ed to the outer cylindrical wall by a cylindrical disc-like section 22, which lies in a plane perpendicular to the longitudinal axis 16 of the gauge. This disc-like portion includes a plurality of 17 cylindrical, inlet ports 24 which run parallel to the longitudinal 18 axis of the gauge. The inlet ports 24 provide a means whereby 19 the chamber 26, defined by the lower end 14 of the housing 12 and the cylindrical disc 22, communicates with the annular chamber 28 21 formed above the cylindrical disc 22, between the inner cylindrical 22 wall 20 and the outer cylindrical wall 18.
23 Sandwiched between the internal thread 16 and the under 24 side of cylindrical disc is a standard "O-ring" 30 constructed from an elastomeric material such as rubber.
26 Additionally, integral with and protruding from the 27 bottom side of the cylindrical disc 22 in an axial direction, is a 28 knife-like annular edge, 32.
29 The upper end 34 of the inner cylindrical wall 20 is formed in a U-shaped fashion. Similarly, the outer cylindrical 1~"676~

1 wall includes a U-shape ridge 36, internal of the wall 18 which 2 also extends the full perimeter of the wall 18.
3 The first enclosure means, 10, also includes an upper 4 housing 40 which is of the same general cylindrical shape as the lower housing 12. Whereas the lower housing can be made of an 6 opaque plastic material for reasons soon to become obvious, the 7 upper housing 40 is made, of a transparent plastic material.
8 Embossed on the outer surface of the upper housing, is a suitable 9 arrangement of numbers 42 in figure 3 positioned sequentially along the axial length of the upper housing wall beginning with 11 the lower number towards the bottom of the gauge, as viewed in 12 Figure 3, ascending to a higher number at the top of the gauge.
13 These numbers represent the pressure range of a gauge given its 14 particular application - e.g. when used to measure tire pressure lS the range would be that shown in Figure 3. To improve the visi-16 bility aspect of the pressure gauge of this invention, these 17 numerals are displayed in identical groupings, spaced 120 apart, 18 about the perimeter of the upper housing wall. One of the other 19 arrangement of numbers can be seen located at 43 in figure 3.
Interposed between each grouping of numerals just 21 described, at 120 spacing, are three groups of axially positioned 22 serrations 44. These cooperate with another "O-ring" 46 and the 23 indicating band 48, whose function and location are described 24 later on to provide a ready indication of the deviations of the tire pressure from the previously set level.
26 The upper housing 40 includes an outer cylindrical wall 27 50 which has an outside diameter virtually the same as the inside 28 diameter of outer cylindrical wall 18 of the lower housing 12.
29 When finally assembled the outer wall 50 nests within the outer wall 18. The bottom end of the outer cylindrical wall 50 as viewed 1~67S~

1 in Figure 2, is U-shaped and together with the U-shaped ridge 2 36 forms substantially, a circular groove into which the dia-3 phragm ring 54 is positioned as soon to be described.
4 Coaxial with the outer cylindrical wall 50 and extend-ing, axially, approximately the same length as the outer wall 15 6 is an inner cylindrical wall 56. soth walls are connected to 7 each other by a disc like member 58 which lies in a plane sub-8 stantially perpendicular to the longitudinal axis of the gauge 9 and which, again, is integral both with the outer cylindrical wall 50 and the inner cylindrical wall 56. The inner cylindrical 11 wall 56 also includes at its bottom end, a U-shaped ridge 60 12 which extends the perimeter of the inner cylindrical wall 56 and 13 whichj together with the ridge formed at the upper end 34 of the 14 inner cylindrical wall 20 provides a circular groove into which -the inner ring 62 of the previously mentioned diaphragm is posit-16 ioned. Both inner walls, 20 and 56, are hollow so that when 17 they c~ aligned in final assembly they form a cylindrical pass-18 ageway 65, wllich runs the length of the gauge, connecting cham-19 ber 26 to chamber 71, the latter being formed as described below.
An annular chamber 64 is formed between the outer wall 21 50 and the inner wall 56. Communicating between this annular 22 chamber 64 and the environment outside the gauge, for reasons 23 soon to become obvious, there exists a vent hole 66 which passes 24 through the disc-like member 58.
Extending axially upward from the disc like member 58 26 is a cylindrical protrusion 68 which is adapted in a known 27 fashion to fit a pump inflating hose. The protrusion, 68, forms 28 a third annular chamber 71. The protrusion 68 is threaded to 29 accept a standard protective cup (not shown).
When completely assembled there is interposed between 31 the U-shaped ridges of the inner and outer walls 20 and 18 of ~ . !

1~96761 1 the lower housing 12 and the inner and outer walls 56 and 50, 2 respectively, of the upper housing 40, a diaphragm assembly 70 3 made of a highly flexible, low friction material such as rubber.
4 It includes an inner ring section 62, sandwiched between opposing U-shaped ridge in the inner walls 56 and 20 and an outer ring 54 6 interposed between the U-shaped ridges of outer wall 50 and ridge 7 36. The diaphragm rings are inter-connected by an annular piece 8 Of flexible rubber material which for purposes of the particular 9 configuration illustrated in Figure 1, is essentially U-shaped.
When finally assembled, rings 54 and 62 are bonded to the ridge 11 sections of the inner and outer walls of both housings. This 12 insures an airtight enclosure into which the pressurized air with-13 in the tire is released.
14 As part of the gauge, means are provided for releasing the pressurized air in the tire into the gauge. Further the 16 releasing means is adapted to provide for inflating the tire when 17 the gauge indicates that the pressure has dropped below a desired 18 minimum. The pressure releasing means preferably includes a steel 19 cylindrical shaft 72 which extends the length of the gauge and which is located at the axial center of the gauge within the 21 passageway 65 formed by the inner wall 20 and the inner wall 56.
22 The shaft 72 terminates in a flange 74 at the lower end 14 of the 23 gauge. The flange lies in a plane perpendicular to the axis of 24 the shaft 72, and includes an annular recess into which is placed a sealing gasket 76 which cooperates with knife edge 32 to form a 26 seal for purposes soon to be described. Press fitted onto the 27 opposite end of the shaft 72 is a bushing 78 generally made of 28 steel.
29 Positioned substantially in the upper annular chamber 3n 64 is located means, 80, for both controlling the variation of the 10 .

~6761 1 volume of annular chamber 28 and for giving to the observer 2 an indication of the pressure in the tire.
3 In the preferred embodiment, means 80 includes a piston 4 like member 82 of cylindrical shape which has an outside dia-meter substantially equal to the inside diameter of the outer 6 wall 50. The piston m ~ er is made of a smooth, plastic-like 7 material which minimizes friction between the surfaces, enhanc-8 ing the sensitivity and accuracy of the gauge.
9 The piston like member 82 includes an axially extending cylindrical wall 84 which barely contacts the inner surface of 11 outer wall 50 and a section 86, integral with the cylindrical 12 wall portion 84 and perpendicular thereto. The inner axially ex-13 tending surface 83 of the horizontal section is in substantial 14 contact with the outer surface of inner wall 56. The underside 88, of the horizontal section 86 has generally, a U-shaped con-16 figuration. The inner and outer extremities, 90 and 92 respec-17 tively, of the U-shaped underside are contoured to take the 18 shape of the inner and outer diaphragm rings 62 and 54 respec-19 tively. This provides an "airtight" seal in a manner soon to be described if and when the diaphragm 70 ruptures. The arcuate 21 contour of the extremities 90 and 92 is better seen in Figures 22 5 and 6.
23 Cylindrically shaped piston member 82 defines a cavity 24 94 between the inside surface of wall 84 and the outside surface of wall 56. Nested in this cavity and extending the axial length 26 of the gauge between horizontal section 86 and disc like member 27 58 is a calibrated coil spring, 96. Spring 96 is preferably 28 made from a suitable spring steel selected to have the necessary 29 spring constant to counteract the force exerted on the piston like member 82 by the pressurized gas in chamber 28 acting 31 through diaphragm 70.

1QI"6761 1 Depicted in Figure 1 is a cylindrical, cup-shapedt 2 covering device 98 of suitable opaque material, such as plastic 3 which hides the "exposed" end of the spring 96 for the purpose 4 of enhancing the appearance of the gauge. Where employed, the covering device includes a vent hole 99 to enable air otherwise 6 under compression in chamber 94, to escape.
7 The indicating feature of means 80 is provided, in 8 combination, by an annular colored band 48 which preferably is 9 painted in a suitable annular recess in cylindrical wall 84.
This insures that the band is not rubbed from the outer surface 11 of the cylindrical wall 84 due to the constant axial movement 12 of the piston member 82 within the chamber 64 when the gauge is 13 in place.

The unit is assembled by first positioning the opaque 16 cover 98 in the upper housing portion 40. The coil spring 96 is 17 next placed within the cover 98 followed by the piston member 82.
18 The diaphragm is positioned in the lower housing such 19 that rings 54 and 62 rest in grooves 36 and 34 respectively. The rings 54 and 62 are secured thereto by a suitable bonding material.
21 The outer wall 18 and the lower housing 12 are then 22 either slipped over the outer cylindrical wall 50 of the upper 23 housing 40 and bonded thereto or, alternately, it is threaded on-24 to the upper housing with suitable bonding cement calking the threads to insure an airtight seal between the contacting surfaces 26 of the two outer walls. Prior to mating the upper and lower 27 housings, bonding material is added to ridges 52 and 60 to there-28 by provide an airtight seal between those surfaces and the top 29 portion of diaphragm rings 54 and 62.
The means for releasing or suoplyi.~ air to the tire is 31 next positioned in the gauge. The flange-shaft unit 74-72 is ~q676~

1 inserted in the passageway 65. The steel bushing 78 is then 2 press fitted over the top end of the shaft 72 thereby retaining 3 the latter in place in the gauge. As can be best appreciated 4 from figure 5, although not depicted therein, a coiled spring member can be interposed between the bottom of the bushing 78 and 6 the top of the disc like member 58 within the chamber 71 to mini-7 mize any rattling of the shaft when the gauge is disconnected 8 from the tire stem, and improve the seal between gasket 76 and 9 edge 32.
Figures 5 and 6, are useful in understanding the oper~-11 tion of the gauge. The gauge is screwed on to the tire valve 12 stem 100 until the top of the valve stem 102 contacts the O-ring 13 30, compressing it as shown. Considering the design of the 14 standard tire valve stem, the height of the flange member 74 of the gauge is such that when the gauge is threaded on the standard 16 valve stem 100 the underside 104 of the flange 74 contacts the 17 valve actuating rod 106 depressing it a sufficient amount, typi-18 cally on the order of .025 to .032 inches, to enable a sampling 19 of the pressurized gas within the tire to enter the annular cham-ber 28 through inlet ports 24.
21 The pressurized gas contacts the diaphragm 70 forcing 22 it upward as viewed in Figure 5 and eventually to the point where 23 it assumes the contour as depicted in Figure 5 which includes 24 conforming itself to the U-shaped underside section 88 of piston 82. The piston member 82 is forced upward in response to the 26 pressure exerted by the gas through the diaphragm 70. Coil spring 27 96 as a conse~uence is compressed between the section 86 and the 28 disc like end cap 58. Because the diaphragm 70 forms an air-29 tight barrier between chambers 28 and 64, the air in compression in chamber 64 is forced out of chamber 64 through vents 99 and 66.
31 As noted earlier the spring constant for spring 96 is chosen so 13.

:

~!C'6761 1 that the force exerted by the spring in opposition to the force 2 exerted by the pressurized gas on the piston like member 82, is 3 such that when the annular band 48 is opposite the appropriate 4 pressure reading on the numerical display 42, the spring force exactly balances the force exerted by the pressurized gas.
6 If it is desired to further inflate the tire, an air 7 pump hose 108, as shown is Figure 6, may be pressed on to the 8 protrusion 68. The valve stem rod 110 positioned in the head of 9 the pump hose 108 contacts the bushing 78. The bushing 78 is depressed and in turn forces a downward movement of shaft 72 and 11 flange 74. The seal formed between gasket 76 and the knife-like 12 annular ridge 32 is "broken" enabling pressurized gas supplied 13 from a compressor (not shown) to pass along the length of the 14 gauge through the passageway 65 past ridge 32 and into the valve stem 100 located on the device to be inflated. The axial length 16 of the bushing 78 is such that the bottom side of bushing 78 as 17 viewed in Figure 6 will not contact the top of the disc like 18 member 58 when the inflating hose 108 is in place. This insures 19 that the seal formed between the gasket 76 and the knife-like ridge 32 is "broken", enabling the tire to be inflated.
21 As the pressure of the gas in the inflated device 22 increases the piston member 82 rises further in chamber 64.
23 The person inflating the device will remove the inflating hose 24 108 when the annular band 48 has reached the desired pressure level. At this time the operator would remove the hose 108 and 26 slip O-ring 46 to a new position on the gauge opposite the band 27 48. A convenient reference is established which subsequently 28 enables the operator to determine whether or not the tire has 29 lost pressure.
Alternately, it may be desirable to release a certain 31 amount of pressurized gas from the tire. In this case, the 14.

1~:3"67~1 1 operator would depress the shaft 72 by pressing down on the 2 bushing 78, thus breaking the seal between the gasket 76 and the 3 edge 32. Downward movement of the shaft will cause the valve 4 actuating rod 106 to further depress resulting in the venting of pressurized gas from the tire, via the passageway 65. The 6 bushing is kept depressed until the annular band drops to a 7 position opposite the desired pressure.
8 Figures 7 and 8 depict in a partial, sectional view, 9 an improved version of the underside surface of the piston member 10 82 which is employed where it is important to have a more sensitive ^~
11 gauge. The improvement calls for providdng a cylindrical append-12 age 112, ending axially from sec~ion 86. The cylindrical append-13 age improves the sensitivity and thus the accuracy of the gauge 14 by reducing the frictional forces occurring between the surface of the diaphragm and the walls which the diaphragm contacts, viz., 16 the inner surface of wall 50 and the outer surface of wall 56.
17 Whereas in the previously discussed U-shaped design, the counter-18 acting force exerted on the piston member 82 by the spring 96 had 19 to overcome a shearing or frictional force at the interface be-tween the diaphragm and the two cylindrical walls as well as 21 compressive forces in the diaphragm, the improvement of Figure 22 7 need only overcome a relatively low adhesive force between 23 the diaphragm and the wall. In effect the diaphragm is "peeled"
24 from the two wall surfaces. Thus the calculations determina-tive of the spring constant can assume, more correctly, "zero"
26 frictional forces with the result that a more sensitive and 27 accurate gauge is developed.
28 Figure 8 illustrates an aspect of the invention, common 29 to the design previously described, i.e., Figures 1, 5 & 6, but which is better pictorialized in Figure 8. This feature might be ~ ~0~67~1 1 called a "fail safe" capability. In effect, this "fail safe"
2 capability prevents the gauge from becoming a device for deflating 3 the tire when the former malfunctions, particularly through rupture 4 of the diaphragm 70. The possibility of diaphragm rupture is a practical consideration after the gauge has been utilized for 6 extended periods of time. This is due in part to the continual 7 up-down movement of the piston in response to pressure fluctuations 8 in the tire. This pressure fluctuation is a continuing thing due g in part to the rough road conditions to which the tire may be subjected, the increase in pressure due to tire heating and similar 11 other disturbances. A ruptured condition is demonstrated in Figure 12 8 by opening 114. Absenttlle "fail safe" design the air passing 13 from the chamber 28 through opening 114 would pass between the side 14 of the piston 82 and the wall 50. However, when the diaphragm ruptures causing a reduction in the force supporting the piston 82 16 in an elevated position, spring 96 forces the piston 82 downward 17 as viewed in Figure 8 until the inner and outer extremities 90 and 18 92 of the underside of the piston contact the diaphragm rings 62 19 and 54 respectively. Sufficient contact area is provided between the rings and the contacting portion of the grooved extremities 21 so that the piston 82 is prevented from any further downward 22 movement. At worst, the pressure in the tire is reduced to an 23 amount such that the force exerted on the piston 82 by the remain-24 ing pressurized gas is just balanced by the spring force exerted by spring 96 at the point of contact between the grooved extremi-26 ties and the diaphragm rings. Further deflation is prevented.
27 The person inflating the tire can detect the fact that 28 the diaphragm in the gauge is ruptured when he goes to inflate the 29 tire. The tire would expand in response to the increasing air pressure but the gauge will fail to respond due to the exiting 16.

lOg6761 1 of the gas through the ruptured diaphragm. Also the piston 82 2 would rise up ever so slightly causing a passing of the air 3 through the vent hole 66 giving use to a hissing sound. Noting 4 this, the operator ]~nows he has a defective gauge.
Figures 9, 10 and 11 are particular variations of the 6 previously discussed design where alternate means for forming the 7 airtight enclosure of variable volume are depicted. For the 8 purposes of discussion with regard to figures 9, 10 and 11, the 9 means for releasing the pressurized gas from the inflated tire, viz., the shaft-flange-bushing arrangement, 72, 74 and 78 respec-11 tively, will not be discussed. Suffice it to say that the operation 12 of this aspect of the particular embodiments of Figures 9, 10 and 13 11 is essentially identical to that previously described.
14 Referring to Figure 9, the chamber 26 vents through inlet ports 24 into an air-tight volume 28 of variable volume which 16 is maintained air-tight by two O-rings one 16 and one 18 which forms 17 a suitable airtight seal between piston 120 and housing walls 122 18 and 124. The overall design of the embodiment of Figure 9 as far 19 as the housing construction is concerned is somewhat simplified in that a gauge consists of a basic cylindrical housing 126 of 21 clear plastic with an end cap 128 either bonded or threaded into 22 the cylindrical opening at the top 130 of the gauge.
23 Two additional O-rings 138 and 140 are positioned in 24 the bottom of the chamber 28, each of the O-rings having a diameter substantially equal to the diameter of housing walls 124 and 122, 26 respectively. When the O-rings 116 and/or 118 wear to a point 27 that they no longer provide an airtight seal between the piston 28 120 and the surfaces of the housing walls 122 and 124, the spring 29 96 will force the piston downward as viewed in Figure 9 until the 30 chamfered edges 134 and 136 contact the O-rings 138 and 140 1 respectively. Through this technique, the l'fail safe" capability 2 described in the earlier embodiment is provided in this configura-3 tion.
4 Suitable pressure indicia would be located on the outer surface of wall 122 as well as serrations for locating the O-ring 6 46. The indicating aspect of the gauge is essentially the same 7 as the one previously described with regard to the embodiment of 8 Figure 1. ;
9 Figure 10 discloses an embodiment wherein the chamber of variable volume 28 is formed by an annularly shaped bellows, 11 142. One end of the bellows 142 is bonded to the bottom of the 12 chamber 44 such that it encompasses the inlet ports 24, thus pro-13 viding an airtight enclosure. The opposite end 146 of the bellows 14 is "capped off" by a lightweight plastic, disc-like member 148, which is bonded in place to the end 146 of the bellows. The 16 disc like member 148 would have the indicator band 48 annularly 17 disposed about its perimeter with corresponding pressure markings 18 again positioned axially along the outer surface of the housing 19 wall. The housing construction is similar to that shown in Figure 9 with the exception that the venting hole 66 is not 21 required. This is so because of sufficient clearance between the 22 member 148 and the inside walls of the housing. In this con-23 figuration provided the seam 150 between the end cap 152 and 24 inner cylindrical housing 154 is bonded, there is no need for the "fail safe" additions of the previously discussed designs.
26 Figure 11 shows yet another embodiment, similar to 27 those just described but where the airtight volume is provided 28 by a flexible, helically-shaped, hollow tube 156 which communicates 29 with chamber 26 through port 158. In this configuration upon release of the pressurized gas of the inflated tire, the gas 31 enters the helical coil 156 at end 157 which is bonded to the inner 18.

q6761 1. surface loO of the bottom portton 162 of the houslng 164. The cotl In response thereto 2. extends itself in an axially upward direction as vtewed In Flgure 11 much In the mannor of th 3. well known BolJrdon tube. Thls conversion of pressure to axlal disp1acement 15 transmltted 4. to piston member 166 whtch i5 made of opoque plast1c and which includes the famtliar r 5. Indicator band 48. The design of the tube and the sprlng constant of the spring 96 are 6. selected so thot the annular band 48 Is posit;oned opposite th~ corresponding pressure 7. Indicat;on on the surface of the housing 164. AgaTn, as was the case wlth tho device of 8. Fiç1ure 10, there is no requirement for a vent hole such as that shown at 60 in Figures 1 anJ 9 ~. Because of the construct;on of the flex1ble tube 15b, which typically could be a lightwetght 10. plasttc or metal the devke is inherently ~fail safe 50 as to preclude the necesslty of pro-11. viding a scheme similar to that Incorporated In the previously described embodtments. In 12. thls destgn the hellcal coil Is wound around the center stem conserving axial length.
13. In another variation of this deslgn, the coil Itself is calibrated such that its 14. ax;al movement is proporttonal to the a;r pressure w;th;n. Th1s eliminates the need for 15. spring 9o, furthcr slmplifylng the design.
16. Finally, a variatton of the basic design of Figure I is shown in Flgures 12 and 13 17. The ba~ic design of Figwe I is Incorporated in thls embodtment which Is Intended to be 18. supplled as part of the arig;nal tire when delivered by the tlre manufacturor or new car 19. dealer. The maln dlfference between the design of Flgures 12 and 13, and those prev;ously 20. descrtbed, is tho requiremsnt that a coil spring 170 bo disposed between the bushlng 78 and 21. the top slde of disc like member 58. Thk spr1ng, 170, In effect replaces or serves the bame 22. function as the spr;ng formally found In the tire valve stem. Sprlng 170 exerts a sufflclent 23. 1 upward pressure as vtewed In Ftguro 12 to maTnhtn a sufflctent seal between the ~asket 76 24. and the knlfe edge 32 to prevent leakoge from the gauge at that polnt.
25. As shown, the outslde surface of outer wall 18 Is bonded to a rubberlzed, tlrc 26 valve structure 172 which Is secured In the 28.
2~.
~0.
19.

10~6761 1 tire side wall 174 in a known manner. The tire would be 2 inflated in the same manner as described earlier.
3 Figures 12 and 13 show a modification of the design 4 previously described which may be a desirable adaptation of the basic design. It includes the provisioning of a filler tube 176 6 which is bonded, in place in the vent hole 66. The filler tube 7 176 would be fabricated from copper or similar material which 8 could be readily cut and then crimped or soldered to provide an 9 airtight termination as shown in Figure 13 at 178.
Employing this variation on the basic design, the 11 gauge manufacturer would be able to preset a given lot of gauges 12 for use at a particular pressure - the one most suitable for a 13 given tire. A range of these type gauges would be provided which 14 covered existing and anticipated recommended pressures as set by the tire manufacturers.
16 During the manufacture of the gauge and after it is 17 assembled, the gauge would be positioned on a suitable tire 18 simulating device which could be inflated to the desired pressure 19 for that gauge. Initially, piston 180 would be forced upward until the top thereof, 182, contacted the underside, 184, of the 21 end cover. (Spring 186 in this application would not be the 22 calibrated type disclosed earlier. Its main function in this 23 application would be to insure that the piston 180 is thrust 24 downward if the diaphragm ruptures to give an indication that the gauge has failed).
26 After inflating the tire simulating device, pressurized 27 gas would be introduced into chamber 64 through filler tube 176.
28 The gas in chamber 64 would exert a downward force on piston 180.
29 The piston would move down and the pressure of the gas supplied through filler tube 176 would be varied until the piston assumed ~"6761 1 an intermediate axial position. The annular band 48, of course, 2 would position itself in a corresponding axial position. A
3 permanent annular, masking band 196 would then be painted on 4 or otherwise permanently affixed to the outer surface of housing 198 at the same axial location as the band 48. The filler tube 6 176 would be crimped and/or soldered or sealed in some other 7 suitable way to prevent the pressurized gas from escaping from 8 chamber 64. The gauge could then be removed from the simulating 9 device and prepared for delivery. The gauge just described would be delivered to tire suppliers or others whose job it is 11 to mount tires. The gauge would be supplied with instructions 12 which would note its particular operating pressure. The supplier 13 would install the gauge-valve device in a tire whose recommended 14 pressure would be that of the gauge. The tire would then be inflated until the annular band 48 positioned itself behind the 16 masking band 196. At this point, the supplier would know that 17 the tire is inflated at the correct pressure for that tire.
18 Subsequently, the motor vehicle operator could tell if 19 the tire was not at the right pressure by noting that band 48 was no longer positioned at the same axial position as indicator 21 band 196. He could then take the necessary corrective action in 22 order to re-establish the proper operating pressure.
23 The approach just described as noted earlier eliminates 24 the need for a calibrated spring and thus provides a less costlier gauge. Further, motor vehicle operators with no idea 26 of the right pressure required by their tires need only know to 27 align the bands 48 and 196 to achieve the proper pressure and 28 thus insure proper operating conditions.
29 It is to be noted in the embodiment depicted in Figure 12, that the previously described means for inflating the tire-1 bushing, shaft and flanges 78, 72 and 76 respectively, could be 2 replaced by a standard valve stem which would be fitted in the 3 disc like end 58 in a suitable fashion.
4 Referring now to flgures 14 thru 18, inclusive, there is shown another variation of the basic invention described herein 6 which requires that the operator o~ the gauge depress the body 7 portion of the gauge in order to obtain a pressure reading.
8 Figure 15 describes a preferred embodiment of such a 9 gauge. It includes a first enclosure 200, formed between an inner housing 202 and an outer housing 204. The two housings are bonded 11 toge~her at annular seams 206 and 208 to form the annular cavity 12 identified as the first enclosure 200.
13 The outer housing 204, is an inverted cylindrical cup 14 made from a transparent material such as clear plastic. As viewed in figure 14, the exterior of the outer housing, 210, has embossed 16 or imprinted thereon a range of numerals 212 corresponding to the 17 range of pressures expected during t~e use of the gauge. As 18 noted with respect to figures 1 to 13, the range of pressures 19 can be positioned at annular increments around the outer perimeter of the housing so that the gauge provides the operator with a 21 360 readout capability. ~urther, groups of serrations (not shown 22 may be interposed between each grouping of numerals to accomodate 23 an "0-ring" indicating band (also, not shown, in the embodiment).
24 m e outer housing is cutout at point 214 to accomodate an annular ring portion 216 of the inner housing.
26 The inner housing, 202, includes a main, hollowed-out 27 cylindrical portion 218. The housing includes a cup-shaped portio 28 defined by annular ~idewall 220. The sidewall terminates at the 29 one end by flanged portion 222. At the opposite end of the inner 3o housing is located the previously ldentified annular ridge 216.

q6~6i 1 As noted earlier the main portion 218 is hollowed-out to form a 2 cylindrical opening 224 which is threaded to accept other parts of 3 the gauge as well as the standard tire valve. Thru holes 226 and 4 228 run through the main portion of the inner housing 218, trans-verse to the longitudinal axis of that member, near the annular 6 ridge end. The circular flanged portion 222, includes an opening 7 230 which is best seen in figure 18. Although not discernible 8 from figure 15, the outside wall 232 of the ;nner housing can have 9 a slight taper to it, being inclined towards the longitudinal axis of the gauge in the downward direction as vie~ed in figure 15. Thi 11 reduces frictional forces asthe "0-ring" is deformed under increas 12 ing pressures 13 A second enclosure, of variable volume is formed within 14 the first enclosure 200. The second enclosure 234 (best seen in figures 19 and 20) is formed by an "0-ring" 236, which is bonded 16 to a piston-like, spacer member 238 by a suitable adhesive.
17 The "0-ring" is a standard catalog item having a thickne s 18 in the plane perpendicular to the longitudinal axis of the gauge, 19 which is slightly larger than the radial thickness of the first enclosure at its widest point, which beca~se of the taper mentione 21 earlier, would be at the bottom of the first enclosure 200, as 22 viewed in figure 15. The "0-ring" exerts sufficient pressure on 23 walls defining the first enclosure such that the leakage of 24 pressurized gas thereby is eliminated.
The piston-like member 238, is an annular ring of suitab e 26 material which has a first surface 240 of concave shape to which 27 the '~ring" is bonded. The axially opposite face or surface of th 28 ring 242 is substantially transverse to the longitudinal axis of t 29 first enclosure but includes an interrupted,annular ridge 244 whic 3o spaces the member 238 off from the inside surface 246 of the 31 outer housing. As noted, the 23.

6761.

1 ridge 244 is interrupted at various locations around its 2 circumference, such at points 248, 250, 252 and 254 in figure 17, 3 to insure that the pressurized gas can contact the maximum area on the surface 242.
Although the "O-ring" and piston-like member are 6 illustrated as separate pieces, to take advantage of the ready 7 avallab~lity of standard sized "O-ring", it is understood that 8 the piston-like member and "O-ring" can be molded from rubber or 9 suitable elastomeric material and formed in one pieces with the profile shown in figure 15.
11 Located in the central portion of the gauge is the valve 12 stem actuating mechanism which allows the operator to either ~
13 take a reading of the pressure in the tire or to inflate same if 14 so desired.
The gas releasing and inflating mechanism includes a 16 cap portion 256, which includes a cylindrical cup portion 258 17 disposed axially from a flanged portion 260. ~xtending axially 18 from the opposite side of the flanged portion 260 is a threaded 19 cylindrical portion 262 which has an outside diameter correspond-20 ing to the inside diameter of cylindrical opening 224 in the main 21 portion 218 of the inner housing. On the inside wall of 22 cylindrical cup portion 258, there ls an annular groove 264.
231 The annular groove 264 has a slanted lower edge 265 disposed 24 axially inward from the upper end of the gauge. The cylindrical cup portion terminates at the uppermost axial end thereof, as 26 viewed in figure 15, in a flanged portion 266 which slightly 27 overhangs the cylindrical opening formed by the main portion of 28 cup 258.
29 The flanged portion 260 of the cap 256 has an outside 3o diameter (O.D ) equal to the O.D. of the outer hou~ing 204.

~ 67~1 1 The under surface 270 of the flange can be bonded to the upper 2 surface of the inner and outer housing by a suitable adhesi~e.
3 This provides an additional airtight seal to eliminate a potential 4 leakage path.
The threaded cylindrical portion or stem 262 is only 6 threaded at the end thereof which meets with the threaded opening 7 224. The portion of the threaded stem 262 nearer the flange 260 8 has the threads removed This provides an annular channel 272 9 which is contiguous with the openings 226 and 228. Further, the threaded stem 262 includes slots 274 and 276 running parallel 11 to the longitudinal axis thereof which provide a channel for 12 directing gas released from the inflatable device to the annular 13 cutout 272 and thence, through the opènings 226 and 228, into the 14 second enclosure 234.
The valve actuator member 278 is a cylindrical member 16 having a U-shaped profile with an axially extending pin member 17 280. At the axially upper portion of the actuator member, 18 there is located a circular flange 282 having an O.D. substantiall 19 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 21 channel for directing gas into the inflatable device.
22 A hose contacting member 290 includes a cylindrical disc 23 292 and an axially extending, rod-like member 294 which makes 24 contact with the valve stem in the air hose.
Positioned at the axial upper end of the gauge is a 26 retainer cup 296 including a main cylindrical portion 298 having 27 a cylindrical opening 300 at the center thereof opening ~nto a 28 larger cylindrical opening 302 defined by ~idewall 304. The 29 main portion 298 includes an annular groove 306 in which there 3o is disposed a suitable "0-rlng" 308. me main portion 298 of Il . 109676i 1 ¦ the retainer cup is of appropriate diameter such that the flange 2 ¦ 266 restricts the upward axial movement of the cup 296.
3 ¦ Interposed between the upper surface of the disc 292 4 ¦ and the under surface.of main portion 298 is a sealing gasket.
5 ¦ 310 which has an inside diameter substantially equal to the 6 ¦ diameter of rod member 294 and is thick enough in the horizontal 7 ¦plane, as viewed in figure 15, to seal off the cylindrical opening 8 1 300. .
9 ¦ Positioned in the opening defined by sidewall 284 is 10 ¦ a spring member 312 which contacts surface 314 of valve actuator 11 ¦ member 278 on the one end and the sur~ace 316 o~ disc member 12 1 292.
13 l Surrounding the sidewall 284 is a second spring 318 14 ¦ which on the one end contacts the under surface of flange 282 15 l and on the other end the top surface of a spanner nut 320.
16 : The spanner nut has a threaded outside perimeter whose 17 diameter is equivalent to that of the cylindrical opening 224.
18 The nut includes an interior opening 322 through which the pin 19 member 280 passes in the assembled position. Notches 324 and .
326 allow for the use of a spanner wrench in the assembly of the 21 gauge~
22 Positioned in the first enclosure 200 is a third spring 23 328 which contacts the upper surface of flange 222 at the one 24 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 26 calibrated to control the movement of the piston-"0-ring"-retainer 27 ring combination, in response to air pressure, such that the 28 last mentioned combination settles at a posltion opposite the 29 marking indicative o~ the pressure of the gas within the inflated 3o device.

1 1~967~1 1 Although Identified in the drawings ^s a separate piece, 2 it is to be realized that the retainer ring 330, may be molded 3 to together with the piston-"0-ring" combination mentioned earlier 4 to form a one-piece unit.
Painted on the radially ou~ward wall of the combination 6 formed by member 238, "0-ring" 236 and the retainer spacer 330, 7 would be a suitably colored annular ring 332 which, of course, 8 moves with those combined pieces to position itself opposite 9 the pressure indication in the range 212 to reflect the pressure of the gas in the inflated device. The "0-ring", 236, itself can 11 provide the necessary indication without the need for an 12 additional painted band.
13 Assembl~
14 The gauge shown at figure 15 is assembled by first positioning the spring 328 around the main portion 218 of inner 16 housing 302 and positioning above that, the "0-ring"-piston 17 member-retainer ring combination 236-238-330. The first enclosure 18 is then formed by cementing the outer housing 204 to the inner 19 housing 202 at the seams 206 and 208.
The cap portion 256 is threaded into the circular opening 21 224 until the flange 260 contacts the top surface of the inner 22 and outer housing~ As noted earlier the under surface 270 can 23 be bonded to the upper surface of the inner and outer housing 24 if desired.
Next the retainer cup 296, with "0-ring" 308 in place, 26 is inserted into the opening defined by cylindrical portion 258.
27 Then the hose contacting member 290, with gasket 310 28 in place is inserted through opening 300. The valve actuating 29 member 278 with spring 312 positioned within the opening formed 3o by sidewall 284 is inserted into the opening defined by ll 10967~1 l 1 Isidewall 258. Spring 318 collars ~idewall 284 and the spanner 2 ¦nut 320 is- inserted into the opening 224.
3 ¦ The nut is threaded up into the opening until the.bottom 4 ¦surface thereof, 334, is flush with the bottom surface 336 of 5 ¦pin member 280. The length of springs 312 and 318 are selected 6 ¦such that when, surfaces 334 and 336 are flush, spring 318 is 7 lexerting an upward force on flange 282 while spring 312 is 8 ¦exerting a~ upward force on disc 292.
9 ¦ Space between the end 338 of threaded stem 262 and 10 ¦the top surface of ~he spanner nut is provided to allow for 11 ¦ adjustment of the spanner nut to compensate for that situation 12 ¦ l~here the valve stem 340 is not flush with the top surface of 13 ¦ the valve wall 342.
14 1 O~eration .
The gauge is threaded onto.the valve wall 342. me 16 disposition of the first enclosure relative to the threaded 17 opening 262 and the valve is such that the second enclosure 234 i8 increases in volume in the direction of the inflatable device 19 as the pressure inside the device increases. This variation 20 of the basic principles of the invention allows for a doubling 21 back of the first enclosure thereby reducing the overall length 22 of the gauge and thus, avoiding breaking the gauge by contact 23 with the curb if in fact it is maintained in place on the 24 tire valve.
Referring particularly to figure 19, there is shown the 26 use of the gauge described in figures 14 thru 18, as it.is 27 employed to read the pressure in a tire. -20 With the gauge in place on the valve wall 342, the .
29 operator places on of his fingers over the opening 302, depressing 3o the retainer cup 296 by downward pressure of his finger. Since 1 ¦ flange member 282 is kept in contact with the under surface of2 ¦ portion 298 of the retainer cup by spring 318, the valve actuator 3 member 278 responds to the depressing force exerted by the 4 operator and moves downward as well. Pin member 280 contacts the valve stem 340 forcing it downward also. After approximately 6 1/32 inches travel, air is released from the inflated device 7 traveling upward therefrom in the direction of the arrows. Air 8 first travels through opening 322, into the portion of cylindrical 9 opening 224 immediately between the top surface of the spanner nut 320 and the surface 338 of the stem 262, and then upward 11 through the slots 274 and 276 into the annular cutout 272.
12 ~rom there it travels into the second enclosure 234 via the 13 circular openings 226 and 228. The force of the pressurized gas 14 working on the surface 242 drives the piston-"0-ring"-retainer disc combination downward until the annular band 332 is positioned 16 opposite the air pressure of the device.
17 Air is prevented from leaking out of the gauge during 18 this operation, along paths 344 and 346 due to the sealing action 19 of the "0-ring" 308 against the slanted lower edge~ 268, of the annular groove 264 and by the sealing action of gasket 310, 21 respectively.
22 When the operator removes his finger from the cup 296, 23 the spring 318 having been compressed further by the action of 2~ the operator taking a reading, exerts a force upward as viewed in figure 19 on the flange 282 such that the retainer cup is 26 restored to the at-rest position sho~m in figure 15. Air 27 trapped in the enclosure 234 slowly leaks out therefrom by 28 passing between the flange 282 and the cylindrical wall 258 and 29 out through the groove 264 and the space between the flange 266 3o and the sidewall 304.

1~"6761 1 ¦ The inflating operation can be best understood by .2 ¦ referring to figure 20. mis shows an air hose 348 connected to 3 ¦ the gauge with the hose valve member 350 contacting the rod 4 ¦ member 294 sO as to drive it downward relative to the retainer 5 ¦ cup member 296. By depressing the air hose contacter 290, the 6 ¦ seal formed by gasket 310 over the opening 300 is broken. Air 7 ¦ released from the hose 348 moves along the path of the arrows 8 in figure 20 into the opening 302, down through the opening 9 300, into the opening 352 and then into the opening 354 by way of the thru holes 286 and 288.
11 The air continues downward through the opening 322 and 12 then into the cavity defined by the valve wall 342.
13 Simultaneously the valve stem 340 has been depressed 14 sufficiently by the cont .cting action of the air hose valve gasket 356 contacting the sidewall 304 of retainer cup 296. As 16 explained with respect to figure l9,.the downward force applied 17 by the valve gasket 356 is transmitted through the retainer cup 18 and the actuator member 278 to the valve stem. The sealing 19 action formed by the cooperation between the "O-ring" 308 and 20 the slanted lower edge 265 of the groove 264 prevents the 21 entering air from exiting from the gauge. Also, as the air hose 22 is pressed down onto the gauge, gasket 356 contacts the top 23 surface 357 of flange 266. This provides an additional seal. I
24 It is to be noted that in addition to inflating the 25 tire, pressurized air entering from the air hose 348 is also 26 directed into the enclosure 234 via the openings 226 and 228.
27 This provides a continuous monitor of the tire pressure while 28 it is being inflated.
29 Upon removal of the air hose from the gauge, the 3o restoring spring 318 forces the actuator member 278 upwaFds until ll 10~6~51 1 the main portion 298 of the cup con~acts flange 266 of the retaine~
2 cup 296. The ~0-ring~ 308 is then positioned in the annular 3 grooVe 264. P~n number 280 moveS upward so that its lower end 4 336 ~ s again flush with the surface 324, whereupon the valve stem 340 closes. Air trapped in enclosure 234 leaks oUt of the 6 gauge in the same manner as described with respect to figure 19.
7 Referring now to figure 21, there is shown a gauge 8 Which is basically similar in all respect to that shown in figure 9 15 except that the means which coacts with the valve stem to eithe~
release pressurized gas from the tire or responds to device 11 inflating means to thus inflate the tire is simplified. In this 12 adaptation the retainer cup 296, actuator member 278 and hose 13 contact 290 are replaced by a single actUating mechanism 358.
14 The member 358 inclvdes a hose contacting button 360 a main 15 cylindrical portion 362 and a valve actuating pin 364.
16 The member 358 is positioned ~n cavity 366 formed by 17 somewhat simplified cap portion 368.
18 ~ me member 358 is captured ~n the cavity 366 and forced 19 upward therein by the action of spring 370 interposed between the under surface of cylindrical portion 362 and the top of the 21 spanner nut 320. `
22 The operation of this embodiment with respect to taking 23 a reading and, as well~ inflating a tire is identical to that 24 disclosed With respect to figures 19 and 20. The main difference here is that the sealing action when taking a reading is 26 performed by the operatorts finger alone. Likewise, when used 27 in the inflating mode, the only seal preventing escape of 28 entering air from the gauge is the one formed by the air hose 29 gasket 356 and the top surface 371 of the cap.
3o Referring now to ~igure 22 there is shown a variation ll lOg6761 1 of the means employed for forming the variable volume enclosure.
2 Again, the details of the construction of the remainder of the 3 gauge are substantially identical to those associated with the 4 gauge of figure 15 or 21. Here, the means forming the variable volume enciosure comprise an annular piston-like member 372 6 which has embeded in its radially inward and outward walls, 7 "0-rings" 374 and 376 of suitable diameter. As air enters the 8 chamber 378 in either the pressure reading or inflating mode, 9 the piston 372 travels within the valume 378 until there is equilibrium between the force exerted by the calibrated spring 11 380 and the pressurized gas working on the surface 382 of the 12 piston. An extension art 384 running axially along a part of 13 the length of the gauge includes a flanged portion 386. On the 14 radially outward wall of the flanged portion 386 is painted a suitable annular band which would locate itself opposite the 16 particular number on the pressure range located on the outer 17 housing, corresponding to the pressure of the gas in the inflated 18 device. Of course, the presence of the arm 384 is not necessary 19 to the operation Or the particular embodiment illustrated, and it is obvious that the "0-ring" 376 itself could perform the 21 necessary indication given a properly calibrated spring 380.
22 The walls 388 and 390 are again tapered relative to 23 each other such that they move away from each other towards the 24 bottom of the gauge as viewed in figure 22.
Referring to figure 23, there is shown yet another 26 embodiment of the gauge which employs yet another means for 27 forming the enclosure of variable volume. The remainder of the 28 gauge is identical to either the embodiment of figure 15 or 29 figure 21. Here, the "piston" member 392 is a cup shaped, 3o annular member, which has flexibly inner and outer edges 3g~

9676~
1. and 396. The edges 394 and 39b are designed 50 C5 to be blased against the walls 398 and 2. 400 respectively, effecting the necessary seal to prevent olr leakage around the member 3. 392. Agaln, the operat70n of the E3auge tn both the reading and tnflatlng modes is tdentlcal 4. to that previously described w;th respect to figures 19 and 20.
5. OF course, modifications to the various embodiments described above can be 6. made by those sk111ed in the art. One such modifTcation would be an elongated verslon of 7. the above descr7bed gauge havtng a more extensive pressure range. Thl5 could replace ~. today s gauge used by gas shtion attendants. It would be screwed onto the tire valve stem 9. when the car is driven into the station, the pressure checked and the tire inflated or deflote- I
10. while the aau~e was In place.
Il. Further, where two or more pTeces have been tdentified, such as the tnner and 12. outer housing of figures 14 to 23, as formtng vartous portions of the gauges described, tho 13. combined piece can be molded as a stng1e piece and obviou~ vartations in the details of the 14. embodiment made to accomodate the molded piece.
15. Re~ferrinEI now to f;gures 24 throu~h 35, there is shown yet another embodiment 16. of the present invention. In this embodiment, gauge, 402, is designed to ut;ltze standcrd 17. vatve cores whlch have been prc>ved through many years of successful use, thu- avoidlng the 1~. need to design a valve core compatible wlth the earller descrlbed embodiment. The gauge 19. shown in figures 24 through 35 also employ an tnterconnectTng arrangement between the 5 . . .
20. standard valve core and the end of the gauge which tnterfaces with the atr pump, which 21. arrangement enables the gas station attendant to ut;l;ze presently ava;lable valve core 22. removal and ;rlsertion tools. He ;s thus able to follow the procedures he presently employs 23. to change or repa;r a flat tire w;thout the need of any speclal tool;ng.
24. The embodiment to be described employs the dou~l;ng back feature of tho 25. ~auge deptcted in flgures 15-23. Howover, the present embod;ment is mounted as an 26. integral part of the rim and tire assembly (llke the embodiment of figures 12 and 13) with the 27. attendant adv~ntages of that arran~ement.
28. One variation of the present em~odiment includes a stem portion whtch 1~
2~. adapted to accept a plwollty of r,pacer washers to achie~e o suff;clent distancln3 from tho 30. l ¦ ri ollow tho indicoting portlon of thl ~0U~ to o posltioned ~uhvrlrd of tho wh el 1. cover for easy ~t1ewing. The stcm includes a threaded end portion for mounting the gauge 2. to th~ whe~l rim. ~y movin~ the spocers from one rlde of the rim ta the other, vartations In 3. the distance the gauge pratrudes beyond the wheel cover can be achieved, thus4. accomodating vorious wheel desi~ns.
5. The second variation of the present embodiment has the stem portion of the 6. acuge embedded in a standord rubber mountin3 rnember which is pressed into the rim much 7. like today's valve stem arrangements. This affordj a fixed spocinS for the gauge and it is 8. rr~ost suitoble for particular wheel designs.
9. ~he gauge of this embodiment lends Ttself to being bent at the stern portion to 10. ollow the upper part of the gauge to fold into the profile of the wheel elim;nating curb Il. tnterference problems.
12. The present embodiment also employs improved indicating means resulting in 13. more accurate readings by the user.
14. Referring now particularly to figure 24 there ts shown one variation of the 15. present embodiment, 402, whlch includes an inflating and reading activat;n3 end 404, lo. contoured as in the eorlier erlbodirnent, to interface with stcndard otr pump equ1p nent and 17. to facilitote pressure reading by allow;ng use of the operator's finger to obtain a pressure 13. r~adin~.
19. The indicatin~ portion of thc gauge, 406, Is disposed in the mid portion o~ the 20. gauge while ths mounting thereof is effccted by the spacer and nut arrangement shown at 40 3.
21. Thc indlcating means 406 con include the number indicta reflectin3 the pressuro 22. range of the parttcular gau~e and serrations disposed o~out the perimeter of the gouge for 23. purposes of securina an 0-rtng at a desired pressure level. tlowever, since the matn 24. purpcse of this e~Tbodiment is to be used as factory installed equipment or, at least, with 25. porticular tire ossem~lies, more often than not, the pressure for that tire will be constant an~
20. set at a particular psT. Thus, a pointed ring, 410, would be positioned on the indicatin3 1 27. portion of the housing at a precalibrated pressure level. This ring would work in conjunc-28. ¦ tion wlth an indicator bant 412, internal to the outer hausin3, which would move in respons 2?. ¦ to octuation of th~ pressure readin3 mechanism, 404. The indicator bond, 412, axially 3C. ¦ aligns itself with the painted band, 410 when the tire ir properly inflated.
1 34.

1 Mounting means, 408, for securing the gauge to rim, 414, 2 includes a plurality of spacer washers, 416, which are interposed 3 between a shoulder on the upper portion of the gauge and the rim.
4 The gauge with the spacers on the mounting stem thereof is placed in the accommodating hole in the tire rim and a sealing 6 ring, 418, and back up washer, 420, placed on the stem and drawn 7 up tightly to the rim by the double locking nut arrangement, 8 422, and 424.
9 The plurality of spacer washers, 416, space the upper portion of the gauge from the rim so that the distance, 426, 11 between the rim and the wheel cover, 428, is sufficient to enable 12 ready viewing of the gauge. The spacing, 430, is a function of 13 the number of spacer washers employed and will vary depending 14 on the particular wheel design.
lS 432 shows the wheel rim in phantom for that arrangement 16 when the wheel cover, 428, is somewhat closer than that just 17 described. Here the sealing ring, 434, is behind the rim with 18 the spacers, 416, (although not shown in phantom) positioned on 19 the gauge stem between the backup washer, 436, and the two nuts, 422 and 424.
21 For a particular stem length, all of the spacer washers, 22 416, must be employed, together with the sealing rim, backup 23 washer and double locking nut arrangement in order that the end 24 of the stem 438 is flush with the exposed surface of the nut, 424.
In a typical design, the spacers can provide 0.700 inches 26 of adjustment in the length of the gauge protruding outward from 27 the tire rim. By placing combinations of the spacers on either 28 side of the rim the position of the gauge outward from the tire 29 assembly can be varied accordingly.
The mid portion of the gauge is preferably covered by 31 rubber sleeve, 440, eliminating "chatter" which might otherwise 32 occur with the banging of the gauge body against the wheel 33 cover, 428.
34 Referring now to figure 25 there is shown a cutaway, sectional view of this embodiment of the pressure gauge.
36 The gauge is seen to comprise an inner housing member 37 442 which includes a first centrally disposed cavity 444

38 extending a substantial part of the length of the gauge

39 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 41 cavity 444 is a second cavity 446 which is threaded in part and 676~
1. contoured to occept a ttandard valve aore assembly. The Inner housin~ further ;ncludes a 2. third cavlty 448 in whlch is disposed the InFlating and pressure reading connectlng assembly 3. 404.
4. Throu3h th 9 woll of the inner housing surrounding the third cavity 448 there Is 5. provlded at least one radially extending thru hole 450.
. The outstde of the upper portion of the inner houstn3 wall def;nln~ the third 7. cavity can be threoded as shown at 452 in order to accept a valve stem cap for purposes of 8. protectlng the inner workin3s of the gauge from the elements and as a l seal" agalnst any 9. leaka~e wh;ch mi~ht result if the core assembly malfunctioned.
10. The outsTde circular wall 454 of the inner housing ;5 a ttghtly toleranced surface Il. for purposes of the tnvention. The surface 4~4 extends o substantial part of the length o~ th~
12. Inner hous;ng term;nattng in a first annular ledge 456 which extends radially a distance untl 13. it is terminoted by a second circular wall 458 having a diameter whlch is substantially con-14. centric with the diametcr of the ftrst wall 454. The second outer wall 45~ extends an 15. additTonal axlal length untll termtnated in a second annular ledge ~oO. The latter termlnat~ s 16. in an outer wall, 4b2, of the ;nner housing.
17. The Inner housing extends further to form a r;m mountin3 portton 466 which has 18. a smooth section 408 extend;n~ a distance comparable to that hken up by the spacer washer~
1~. 416 and the sealin3 ring and back up washer, 418 and 420. This insures an optimum seal by 20. ¦ the seal;ng r;ng 418 and the mountin~ stem of the cauae to avold leakage therebetween. The 21. mounting portion 460 terminates in a threaded section 470 for receiving the double nut 22. arrangement 422 and 424 whtch cooperate to ~ecure the aauge to the tire r;m.
23. The Indiccting means for this embodiment is shown at 474. It comprises an 24. annular collar 476 whlch has an inside diameter substantially equal to the diameter of tho 25. surface 4!;4 of the inner housin~. The collar includes an annular groo~ e 478 which hos a 26. painted 6and 480 on the radtally Inward surfoce thereof.
27. rhe indicating means further includes a cyltndrically shaped extension arm 482 28. wh;ch terminates in an annular flonge ~ection 484.
2~. Posltioned on the top surface 48~ of the collar 47b is an annular, channel 30. shaped portton 486 which may oe formed as an integral portion of the indicating means ~6.

1. member 474 or be a separate piece whTch i5 cemented to thc top surface thereof.
2. The reoson tor the cyllndrically shaped indicatin~ means havlng a flanged end 3. section 484, is to eliminate the tendency for such a conft3uration to cock due to the 4. unsymmetrical force exerted on the under surface 487 of the onnular collcr 476 by the top 5. co71 488 of the spring 472. The flange section i5 designed such that It w111 contact the 6. inner wall of the out~r housing before any significant tiltin~ of the collar part10n can take 7. ploce. The len3th of the extendecl arm 482 takes into considerotion the qmount of tllt that 8. mi3ht be expected due to th;s unsyrnmetrical fcrce ond the clecronces and manufactur7ng t 9. tolerQnces of thc involved pieces sa as to eliminate ony s1c~nificant tiltin~. This deslgn 10. feature also eliminates scorin~ of the inside surface of the outer housing by the annular Il. collar 476. ThTs insures continued vtsibil1ty of the band 480 over the life of the gau e.
12. Positioncd in the channel 486 is a V-shaped seal 490. Its mating surfac with 13. the channel is shaped and contoured to odapt thereto rec;dily. The open portion of the V-14. shape~ is directed away fro-n the chc~nnel.
IS. Surrounding the inner housing, th~ calibrated sprin3, and the Indicating meqn~, 16. is an outer hous;ng rnember 492. It tncludes an annular collar 4~4 which hqs an Tnner 17. dtameter sub~tan:;al!y cqual h the diameter of the outer wall 454. Extendin3 axially down-18. ward from the collar as viewed 1n figure 25 i an annular protrusion 496 which includes at 19. least one rqdially extending thru hole 498 or slit cut into the protrusion. The hole 498 20. communicates wtth the thru holes 450 via the qnnular cavity, 499. The protrusion at 496 21. Includes an annular rid3e portion 500 whlch stabltzes the seal 4O tn the at-rest pos7tion to 22. thus elimtnate btndin3 o~ the seal agairlst the mating surfoces of the tnner and outer hous1ng.
23. The houstng further includes a cyl;ndrical wall 502 which extends o substantial 24. part of the gauge, resting on ledge 460. The inside surface 504 of the wall is likewise a 25. tightly toleranced su~ace qnd i~ concentrlc with the surface 454 of the inner housing -1n 26. a typical situation ta within a .001 Inches. Radial hole 505 ;s c!rilled thru the wall 502 and 27. 51eeve 440 to reduce the back pr2ssure behind the indi_ating meons during operation.
28. A collqr ring 506 Is threaded on to ths upper end of the inner housing and 29. cemented to the top surfqce of the collar 494 of the outer housin~ to k~ep the assembly inhc 30. and qirtight.
37.

~09676~

1 Referring now to figures 26, 27 and 28, there follows 2 a detailed discussion of the assembly and interconnection of 3 the standard valve core assembly 508 and the inflating-4 pressure reading interconnecting assembly 404.
The inflating and pressure reading interconnecting 6 assembly, 404, comprises an extension shaft 510 which includes 7 a cap portion 512 connected to a cylindrical portion 514. The 8 latter is joined to a square or rectangular section 516 which 9 terminates in a cylindrical cup portion 518.
The cap portion of the shaft includes an arcuate section 11 520 including, as is seen in figure 27, flattened surfaces 522 12 and 524 which facilitate use of a standard valve core removal 13 tool to extract the interconnecting assembly from the gauge.
14 The cap, 512, further includes a cylindrical disk portion 526 which is disposed between the arcuate section 512 and the 16 cylindrical portion of the shaft 514.
17 A bleeder hole arrangement including hole 528 along the 18 longitudinal axis of the shaft 514 and a hole 530 transverse 19 thereto are drilled in the shaft and connect the top of the arcuate section with the cavity 532 surrounding the shaft 514.
21 The end, 534, of the cylindrical cup section 518 is 22 rolled over the raised portion 535 of the valve stem 536.
23 This makes the extension shaft an integral part of the valve 24 core assembly.
The interconnecting assembly 404 further comprises a 26 coupling collar 538, which locks the extension shaft 514 to the 27 valve core assembly, to enable the integral unit to turn as if 28 it were one assembly. The collar in the embodiment described 29 is basically cylindrically shaped with appropriately contoured cutouts which fit over coacting portions of the shaft extension 31 and valve core assembly. E.G., the upper portion 540 of the 32 collar is either square or rectangle or can be keyed, whatever 33 is appropriate, to be compatible with the corresponding portion 34 516 of the shaft. The lower portion of the collar, includes a cutout 542 which bridges the flats, 544 and 546, of the standard 36 valve core assembly, normally used with an appropriate tool to 37 remove that assembly from the tire.
38 Thus it can be seen that the collar 538, locked 39 by the upper cutout 540 to the extension shaft and to the valve assembly 508 by the cutout 542, provides 41 for unison movement of the shaft extension and valve 42 core assembly when rotated. Thus by connecting a 1~- 10~6761.
standard valvc removal tool to the flats 522 and 524 of the cap 512 and rohting sarne, this 2. rotational rnovement is transm7tted via the sh~t 514 to the standard core assembly 508 thus 3. enabling lts removal from the gauge. ~his embodlment is thus seen to utillze tools that ~re 4. presently readily avotloble and not of special design.
5. U/hile the standard core assembly outlin_d Is seen to be th~ type where the 6. sealina spring is internal to the core body, it should be cpparent that this c,nbodiment is 7. reodily adopted to utilize that typ~ of core assembly where the sealing spring Is external to ô. the valvs body.
. The interconnecting assembly 40~ further includes a butterfly valve 5~8 which 10. has an 0.1:~. somewhat larger than the 1. D. of the Inner surface 550 of the inner housing 11. and an inside diometer substantially equal to the O.D. of the cylindrical portton 514 of the 12. shaft 510. The valve 548 Is made of an elastomer;c material which can withstand air 13. pressures during the tire filling operation in excess of the pressure range of the ~auge so that 14. it is able to allow for the passage of air into the tire but prevent the leakaae of air there6y 15. during the reading mode.
16. The asscmbly 404 further includes a backup washer 552 which holds the butter-17. fly valve ~ agatnst the disk portlon 526 of the cap through the force of spring 55~',. The 18. latter spring has an l.D. approximately equal to the diameter of the cylindrical portion 514.
1~. The spring sits on the top of collar 53â and i5 biased against the flat washer 552 in the at-2t). rest mode. The sprlng through its exertion of an axially dtrected upward force on the shaft, 21. provides a pos;tive force on the valve stom 536 insuring th~t ;t is mointained in a closed 22. position. It also thrusts the butterfly valvc upword to provlde a tighter seal at the 23. extremtttes thereof wTth the surfoce 550. Thls Inherently forces the operator to ploce his 24. flnger over the bleeder hole 528 ond to exert sufficient force, when taktng a reading as to 25. Insure sealing thereof.
26~ To osssmble the Interconnecting assembly 404 wlth the standard valve assembly 27. ~08 before inscrtion into the aouge unit, the valve 54~ and flat washor 552 are first placed 28. over the shaft 514. ~he spring and coupling collar are then set in ploce with the coupling 25'. collar forced up the shaft (as viewed in figuro 26) until thc bottorr~ thereof cleors the cup 3C. Slû he end of thc cup 534 It then rolled over the rid3e 535 thlls maklng thc iwo piecct 10~'~67~;~
1. inte~3ral, whereupon the collar is released.
2. Referrlng now to ftgures 2~ and 30, what follows is a déscription of the rcad;ng 3. ond filling operations rr!lploying the embodTment of the sauge presently under discusslon.
4. Referring initially to flQure 29, the user in attempting to cletermlne the tire pressure places 5. a finger on the top of the gauge housing covering the hole 528 ond forcTng ~he shoFt 514 6. d~wnward. ~he bottom of portion 516 of the shaft moving axially contacts ~he valve stem 7. 536, depressing it into the core assembly thus releasing the air from tho tire. The releascd 8. air follows the path of the arrows 555, tnTtially upword in the first channel ~56 then trans-9. verse to that ckann_l through a second channel for~,ed by the radially disposed holes 558 10. and 560. The rele~sed air passes int:7 th- enclosures on e;ther side of the axially extending Il. ?rotrusion ~ and exerts itself symetrically on t'ne upper surface of the seal 4Q0. Thc 12. resulting force on tl~_ seal drives the extre nities thereaf against the maiing walls of the 13. inner and outer housing and forces the tndicating ~eans 474 down~ard. The clibrated 1~. sprir.g 472 resists this motion and when its displacement results in a force equal to that .
15. exerted by the air pressure, the indicatin, means assumes an equilibrium posltton.
lo. At tl-at point, the painted band in gro~ve 47S is d;sposed opposite i7. the appropric,te indicia on the outstde of the outer houslng 4~2 correspond;n3 to the pressure 18. within the tlre.
19. The groove 478 ls cut deeply enough into annular collar 470 50 that user must 20. view the band in the groove almost perpendicular thereto. Thus the distance 560 betwecn 21. thc actual psl reading and the apparent ~p5t reading" is mini~nized to reduce the parallax 22. error in gQu3e reading.
23. During the reading cperation, while thc finger is still Tn place on top of the 24. gauge, the released prcssurized air is prohibited frolll venting from the gauge via holes 530 25. and 528. Also, the r-leasod air cannot escape post the butterfly valve 548 because of Ih 26. inherent resistance h the forces exerted by the pressures onticipated within a tire for a giver 27. gauge cj>plt c ation.
2~. After the reoding the Fingsr is removed and the shaFt 514 is returned to the at-2~. rest p~sttion by the force exert~d by the sprir.g 55~ and th~ ss~rin3 ln tl:e core assernbly.
30. Valve stem 536 closDs prohibiting further reiease of the pressuri~ed air. The air trappod In 1 the channels 556, 558 and 560 as well as the enclosure of 2 varying volume above the seal 490 , bled off from the gauge 3 through the holes 530 and 528.
4 Figure 30 depicts the filling operation. The air pump nozzle 568 is placed over the gauge as is normally done with 6 present valve core assemblies. The pressure of the air in the 7 pump, is sufficient to force the perimeter of the butterfly 8 valve 548 downward allowing for the entry of the pressurized air 9 into the gauge. For a typical design, this pressure requirement might be in the vicinity of 40 psi or greater.
11 The nozzle 568 contacts the button portion of the stem 12 510 forcing the shaft downward such that it depresses the valve 13 stem 536. The pressurized air from the pump proceeds down the 14 channel 556 into the core assembly 508 and into the cavity 444 whereupon it enters the tire. When the tire is at the antici-16 pated pressurized level, the nozzle can be removed and the actual 17 pressure checked according to the procedure set forth with 18 respect to figure 29. If more air is needed the nozzle can be 19 replaced in position or, if in the first instance too great a pressure had been applied, the air can be released by success-21 ively depressing the interconnecting assembly allowing the air 22 to vent through the bleeder holes 530 and 528.
23 Referring now to figure 31 there is shown an alternate 24 sealing arrangement to use in lieu of the butterfly valve just described. The sealing valve assembly 570 comprises a modified 26 cap portion 572 including an extended disk portion 574 having an 27 annular groove 576 cut therein. Positioned in the groove is an 28 O-ring of appropriate elastomeric material.
29 The inner housing 442 is modified from that described in figure 25 so as to now include a cutaway portion 582.
31 The distance between the location of the O-ring and the 32 top of the cutaway portion is such that when the stem 584 is 33 depressed for purposes of taking a reading, the O-ring does not 34 reach the cutaway portion 582. This prevents leakage of the released air past the stem and insures that it is directed into 36 the area of the seal 490 which reacts as described with respect 37 to figure 29. However, when the tire is being filled the air 38 pump nozzle depresses the stem 584 deeper into the body of the 39 gauge such that the O-ring now is disposed in the cutaway area 582. The dimensions of the O-ring are such 41 with respect to the diameter of the cutaway section 582, 42 that the pressurized air from the air pump nozzle 10~

1 can pass therebetween and thus fill the tire.
2 Figure 31 also depicts an adaptation of the presently 3 described embodiment of the invention which allows for its 4 utilization as a gauge to be screwed on to a standard valve stem already in place in a tire.
6 Referring now to figure 32 there is shown an alternate 7 to the "V" shaped seal 490, described in figure 25. The annular 8 ring seal 586 comprises a central portion 588 which is sub-g stantially rectangle in profile but includes a groove cut therein at 590 which mates with the annular ridge 500 of the axially 11 extended protrusion 496.
12 The annular ring 586 further includes angled wing sections 13 592 and 594 which extend radially outward and inward, respec-14 tively, from the rectangular portion 588 to provide a seal against the corresponding surfaces of the inner and outer 16 housing. When the gauge employing the type seal shown in figure 17 32 is activated for purposes of obtaining a reading, the 18 released gas enters the enclosures 596 and 598 as with the "V"
19 seal so as to exert an equal force on each of the two annular wing sections. This insures that a symmetrical force is 21 exerted on each of these sections so that there isn't a 22 "sticking" of the seal to one surface or the other due to an 23 unbalanced force.
24 The seal may be bonded or cemented to the annular collar 476 of the indicating means although this is not necessary, and 26 drives the latter downward in response to the force in the 27 identical manner described with respect to the "V" seal.
28 The dimensions of the seal, particuarly the annular wing 29 sections and the material thereof are selected to provide an adequate seal against a blow-by of the pressurized gas but, at 31 the same time, afford a minimum resistance to the force exerted 32 by that gas in order that the seal not hang up.
33 Figure 33 shows an adaptation of the gauge of the 34 presently described embodiment which employs two painted bands 600 and 602 on the outer surface of the outer housing. This 36 accommodates a typical situation found with respect to the 37 pressure differential between tires located on the front wheels 38 and tires located on rear wheels. Original equipment 39 manufacturers can use this simple technique to preset the tire pressures for the front and rear tires for a particular 41 tire size and vehicle. The tires to be used on the front 42 of the vehicle would be pressurized until the indicator 43 band 604 aligns itself with the upper band 1~9~76~

1 as viewed in figure 31 - representing the recommended tire 2 pressure for front tires. The same would be done with respect 3 to the rear tires except that now the tires would be pressurized 4 until the band 604 lined up behind the painted band 600 set at the recommended pressure for the rear tires.
6 Thereafter, in use, an operator would only have to check 7 the pressures in each of the tires to make sure that the band 8 604 was aligned behind either one of the two painted bands 600 9 or 602 - depending on whether it was the front or rear tires.
This convenience would eliminate the operator's need to refer 11 to an owner's manual or the like to check the recommended 12 pressure.
13 Figure 34 depicts a modification of the present embodiment 14 where the mounting stem 606 is bent to accommodate these applications where an upright adaptation for the gauge might 16 result in curb clearance problems. The bent stem folds the 17 gauge body into the profile of the wheel thus avoiding these 18 problems. Since only the stem is bent, the operation of the 19 gauge is unimpeded and is identical to that described above.
Figure 35 depicts yet another adaptation of the basic 21 gauge design of this embodiment wherein the method for mounting 22 the gauge body to the rim employs a standard valve seat 608 23 which is cemented or otherwise affixed to the gauge body 610.
24 This is a suitable means for securing the gauge to the rim in those circumstances where the wheel design is fixed and there 26 is no need for the mounting adjustment feature described above.
27 This is most appropriate again as part of the original supplied 28 equipment for a car where the design and profile of the wheel 29 is known and can be accommodated.
Referring now to figure 36, there is shown still 31 another embodiment of the present invention. The version of 32 the invention depicted, as with the previous embodiment, 33 utilizes standard valve cores but is a somewhat simpler and 34 less complex version.
It, too, employs the doubling back feature of the 36 embodiment shown in 15, but like the embodiment shown in 37 figures 24 through 25, it is mounted as an integral part of 38 the rim and tire assembly either employing the threaded stem-39 nut connecting arrangement or the molded rubber adaptation.
It is readily seen from the drawings and the 41 accompanying discussion that practically all of the modifi-42 cations and variations described with respect to the earlier lQq~67~1 1. I embodiments are likewise applicable to this adaptation as well.
2. The design shown in figure 36, gauge 700, includes an inner housing member 3. 702 having a first centrally disposed cavity 704 communicating axially with a second cavity 4. 706 which is threaded and contoured, as at 708, to accept a standard core unit (see figure 5. 28), such as 710.
6. Cut into the inside threaded wall of the second cavity 706, is an axially .-7. extending cutout 712. This is better seen from the plan view in figure 37. This runs 8. parallel to the longitudinal axis of the gauge and provides a passageway whereby the cavity 9. 706 is able to communicate with an angled thru hole, 714, which in turn communicates with 10. the enclosure 715.
Il. As before, the outside wall of the second cavity is threaded as at 716 to accept 12. a standard valve cap or the dual purpose cap to be described hereinafter.
13. The outside circular wall 718 of the inner housing extends a substantial length.
14. At the tire end, an end piece 720 is press fitted thereon. The latter includes a first 15. annular ledge 722 which is terminated by circular wall 724. Typically, the circular wall 16. ¦ 724 is concentric to within .001 inches of the surface 718 of the inner housing. The circular 17. ¦ wall 724 extends from the ledge 722 to a second annular ledge 726 which provides a flange 18. ¦ surface against which abuts grommet 728 which is interposed before the flange and the tire 19. ¦ rim, 730, and the threaded end, 732, of end piece 720. Nut 734 is used to secure the 20. ¦ unit to the rim.
21. ¦ The upper end, 736, of the inner housing includes an annular collar, 738. This 22. ¦ provides a ledge 740.
23. ¦ Indicating means, 742Jsimilar to the design previously described with respect 24. ¦ to the embodiment in figures 24 and following. It includes an annular collar 744 having an 25. ¦ annular groove 746 with suitable painting or other marking disposed therein. Although not 26. ¦ shown as pronounced as in figure 25, it is understood, of course, that the groove 746 may be 27. ¦ cut as deeply as the earlier described embodiment.
28. I The indicating means further includes a cylindrically shaped extension arm 748 29. connected to the annular collar 744 and directed longitudinally towards the tire. This 30. exten on terminates in an annlllar flange section 750.

~1 lag~7~

1 . Disposed on the top side of the annular collar 744 is an annular elastomeric seal 2. 752 which is cemented or otherwise secured to the top surface 754 of the collar 744. Biased 3. against the undersurface 756 of the collar, is the top coil 758 of calibrated spring 760.
4. The bottom coil of the latter, 762, rests on the ledge 722.
5. A cylindrically shaped, clear plastic housing, 764, forms the outer housing 6. member and is disposed between the ledge 740 of the inner housing member and the ledge, 7. 726, associated with the end piece 720. The housing is bonded to the ledge at 740 to ..
8. provide an airtight seal. The inside surface 766 of this outer housing member is relatively 9. tight toleranced and typically~ concentric with the surface 718, again, to within .001 inche s.
10. Further, for purposes described with respect to the earlier embodiments, the cylindrical Il. wall includes a vent hold 768.
12. ¦ Because of the manner in which air is introduced into the expanding enclosure, 13. ¦ and the particulars with respect to the design of the elastomeric seal 752, it, typically, 14. ¦ will require means for keeping the seal from closing off the thru hole 714. This is 15. ¦ accomplished with the use of a snap ring 770 disposed in an appropriate groove in the inside 16. ¦ wall 766 of the outer housing member. The ring limits the upward movement of the indicat-17. ¦ ing means so as to prevent the constant spring force exerted by spring 760 from deforming 18. and causing cold flow of the seal, 752, which, otherwise, would cause a wedging effect 19. making the gauge inoperative.
20. As before, the gauge of the present embodiment can include an "anti-rattle"
21. protective covering 771 to eliminate noise between the gauge and the wheel cover.
22. Referring now to figures 38 and 39, there is shown an elastomeric seal which is 23. considered to be of suitable design for this embodiment. It includes a semi-circular ridge 24. ~ 772 which extends to angled wing sections 774 and 776. The latter are then juxtaposed to 25. the relatively rectangular section 777. The seal rests on surface 754 of the collar 744 and 26. may be cemented thereto if found necessary.
27. The ridge section 772 of the seal includes a plurality of slits 778 which affords 28. appropriate passageways for the air entering the enclosure 715 to contact and coact with 29. ¦ the winged sections 774 and 776. This allows for a balanced force to be exerted by the air 30. ~ entering the enclosure on the seal, which in turn, minimizes the cocking of the indicating 1 ~I means. I
2. ! The ridge 772 rests in groove 779 when the gauge is not being used. The 3. durometer of the elastomeric seal 752 is chosen so as to avoid a closing down of the air 4. passageways. This,plus the effect of the snap ring 770,allows for the air to pass to either 5. side of the ridge ~

1~ lQ~6761 1. 1 when the indicating means is in the at-rest position.
2. ¦ Referring to figures 40 and 41, alternatives to the snap ring approach of figure 36 3. are shown. In figure 40 an annular ridge 780 is molded on to the inside wall 766 of the 4. outer houiing member 764. This ridge engages the flange 750 and provides the necessary 5. effect to keep the ridge portion 772 of the seal from closing off the thru hole 7140 In figure 6. 41, a ledge, 782, is molded in the inside wall which coacts with the flange 750 to achieve 7. the same end.
8. Figures 42, 43 and 44 depict various cap designs which provide a normal closure for 9. the gauge and which include on their opposite end, a means for actuating the valve in the 10. embodiment shown in figure 36, to thus allow the taking of a pressure reading. The cap to Il. be described would also have application to the embodiments shown in figures 14 through 22.
12. Particularly referring to figure 42, the cap 784 includes a centerpost portion, 786, 13. ¦ and a circular side wall portion 788. These define an annular cavity into which is placed a 14. gasket 790D The width of the cavity is such that the cap may be placed over the end of the 15. gauge just described without there being significant lateral movement. This insures that the 16. centerpost 786 will contact the actuated portion 792 of the valve core assembly. The gasket 17. 790 is disposed in the cavity and cooperates with the end of the gauge to seal that point to 18. thus prevent the escape of air when the reading is being taken.
19. When the cap is employed to take a reading, air flows out of the 20. tire, up through the standard core assembly 710 and into enclosure 715 via the cutout 712, an~
21. angled thru hole 714. The direction of air flow is shown by the arrow 794, in figure 36. The 22. air entering the enclosure 715, is directed onto the winged sections, 774 and 776, of the 23. seal and exerts a force thereon to drive the indicating means downilard until the painted 24. groove 746 aligns itself with the corresponding pressure marking.
25. The cap further includes a knurled section 796 for ease of removal. The internal 26. portion of the cap which is normally disposed on the end of the gauge includes a cutout 27. section 798 of appropriate design so as not to actuate the end 792 of the valve stem in the 28. at-rest position. The internal portion of that end of the cap is threaded at 800 so it may be 29. screwed on to the gauge. It may further include a gasket 802 to eliminate leakage.
30. Figure 43 shows another adaptation of the dual function cap where the portion which j~` lQ~S761 ,- I
1. interfaces with the gauge during the pressure reading mode includes a threaded inner wall 2. 804 which screws on to the end of the gauge until centerpost 806 contacts the valve 3. actuator. Again, gasket 808 seals the end of the gauge to prevent leakage. Figure 44 show 4, a threaded centerpost 810 which scre~s into the gauge until the gasket 812 seals off the end.
5. Although the various caps shown are metal and employ gaskets to seal the gauge, it 6. is understood that the cap can be made from a suitable elastomeric material which provides 7. the means for sealing in and of itself.
8. The gauge depicted in figure 36 is a lighter weight adaptation of the present 9. invention which has less of an impact on the balance of the tire and results in less stress on 10. the rubberized mounting when such is used to secure the gauge to the tire rim. Further, the Il. adaptation just described is smaller in diameter which enables it to be utilized with standard wheel covers.
13. Other variations of the specific constructions disclosed will be apparent to those 14. skilled in the art and must be considered to be within the breadth of the invention as defined 15. in the appended claims.- . ~- ~---16. - . ` ' . . ~ .
7 ` - ; ~ . -- - -`

, ',.' ',' . `,' ' ' ''~' ''. '" , .' ;. ':
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24.

, ..

.

Claims (23)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A gauge for measuring the pressure of an inflatable device which comprises:
(a) a valve stem assembly centrally disposed within said gauge;
(b) means for forming a first enclosure, said first enclosure concentrically disposed outwardly of said valve stem;
(c) means for forming a second enclosure of variable volume within said first enclosure;
(d) means for affixing said gauge to the inflatable device;
(e) first channel means for directing gas released from within the inflatable device via said valve stem axially away from said inflatable device;
(f) second channel means, communicating with said first channel means, for directing the released gas radially outward from said first channel means and into said second enclosure;
said second enclosure increasing in volume in an axial direction toward the inflatable device for increasing gas pressure;
(g) means for controlling the variation of the volume of said second enclosure such that said variation is proportional to the pressure of the gas; and (h) means for indicating said variation in response to the pressurized gas to thereby give a measure of the pressure of the gas.

2. The gauge of claim 1 wherein said indicating means includes:
(a) an annular band adapted to move axially in response to the variations of the volume of said airtight enclosure;
(b) a transparent housing comprising that portion of said first enclosure wherein said annular band moves; and (c) at least one grouping of numerals, each grouping extending axially along the length of said transparent housing and corresponding to the range of pressures to be measured by said gauge, each grouping positioned radially about the perimeter of said transparent housing a predetermined distance from another grouping.

3. The gauge of claim 1 wherein the means for forming said second enclosure comprise an O-ring bonded to a piston-like member which moves within said first enclosure in response to the pressure of the gas.

4. The gauge of claim 1 wherein said indicating means is a piston-like member which moves within said first enclosure along the gauge in an axial direction in response to the pressurized gas and wherein said second enclosure is formed by the interposition of "O-ring" means between the side walls of said piston and the corresponding inside walls of said first enclosure.

5. The gauge of claim 1 wherein said means for forming said second enclosure comprise a piston member, having a cup-shaped cross-section, opening outward in the direction of the gas entering said second enclosure and including feathered edges biased against the walls forming said first enclosure to thereby form said second enclosure.

6. The gauge of claim 3 wherein said first enclosure tapers from a smaller to a larger opening in the direction of increasing volume for said second enclosure, whereby the friction-al forces opposing movement of said "O-ring" in response to in-creased pressure are minimized.

7. The gauge of claim 4 wherein said first enclosure tapers from a smaller to a larger opening in the direction of increasing volume for said second enclosure, whereby the frictional forces opposing movement of said "O-ring" means in response to increased pressure are minimized.

8. The gauge of Claim 1 wherein said valve stem is a part of said inflatable device said means far affixing said gauge to the inflatable device including means for affixing said gauge to the valve stem.

9. The gauge of Claim 1 wherein the means for forming said second enclosure of variable volume includes a V-shaped seal operatively connected to said indicating means, said seal having the opened portion of said V-shape directed in an axial direction away from said inflatable device, said seal coacting with said indicating means in response to the released gas entering said second enclosure to cause said second enclosure to increase in volume for increasing gas pressure.

10. The gauge of claim 1 wherein said means for affixing said gauge to the inflatable device include:
(a) an elongated mounting stem, said mounting stem including a cavity connecting said inflatable device to said valve stem for directing gas to and from said inflatable device from said gauge;
(b) a plurality of spacer means positioned on said mounting means for spacing said first enclosure a desired distance from said inflatable device; and (c) locking means for securing said stem to said inflatable device.

11. The gauge of claim 1 further comprising means for coacting with said valve stem to release the pressurized gas within the inflatable device, said coacting means also adapted to respond to device inflating means to thereby cause the device to be inflated, said means for coacting including:
(a) a cap portion for cooperating with an operator's finger on said device inflating means;
(b) an extension shaft including first and second geometrically shaped and axially extending sections connected to said cap portion, said shaft further including a valve stem (claim 11 cont'd) coupling section, said coupling section secured to said valve stem whereby said valve stem is axially removable from said gauge in unison with said shaft;
(c) a coupling collar including, (i) a first cavity, said first cavity geometrically shaped to conform to the outline of said second extending section of said shaft, (ii) a second cavity, said second cavity geometrically shaped to conform to a correspondingly shaped section of said valve stem; whereby rotational motion applied to said cap portion is transmitted through said shaft to said coupling collar and in turn to said valve stem such that said valve stem can be removed from or inserted into said gauge; and (d) a sealing valve arrangement concentrically disposed about said first section of said shaft, said valve arrangement providing the necessary resistance to gas released from said inflating device to prevent said released gas from escaping from said gauge, said valve arrangement further adapted to respond to device inflating means so as to enable pressurized gas to enter said inflatable device around said scaling valve arrangement and through said gauge.

12. The gauge of Claim 11 wherein said cap portion in-cludes flattened surfaces for coacting with valve stem removal and insertion tools.

13. The gauge of Claim 11 wherein said shaft includes a bleeder hole arrangement, said bleeder hole arrangement communi-cating between the environment outside the gauge and said first channel, whereby released gas is vented from said gauge after the taking of a pressure reading.

14. The gauge of Claim 11 wherein said means for coacting further comprises, a spring member concentrically disposed about said shaft and biased between said coupling collar and said seal-ing valve arrangement, said spring member exerting a positive force on said sealing valve arrangement so as to insure an air-tight seal thereof when said gauge is not in use and further exerting a positive force through said shaft on the seal portion of said valve stem so as to insure an airtight seal thereof.

15. The gauge of Claim 14 wherein said sealing valve arrangement includes a butterfly valve disposed about the cylin-drical portion of said shaft and interposed between said spring member and said cap portion.

16. The gauge of Claim 11 wherein said sealing valve arrangement includes an O-ring shaped valve disposed in a corre-sponding niche in said cap portion.

17. The gauge of Claim 1 wherein said means for indi-cating includes, (i) an annular collar having a concentric groove cut therein, (ii) a cylindrically shaped extension arm extending axially from said annular collar towards said inflatable device, (iii) seal means disposed upon said collar and responsive to the force exerted by said released gas to drive said indicating means axially towards said inflatable device, and (iv) an indicating band disposed in said groove, said band aligning with suitable markings on said first enclosure forming means to indicate the pressure of said released gas.

18. The gauge of Claim 17 wherein said means for con-trolling the variation of the volume of said second enclosure is a spring member disposed between said annular collar and said first enclosure forming means, said cylindrically shaped exten-sion arm of said indicating means including a radially extending flange member fixedly connected thereto, said flange member coacting with said first enclosure forming means to prevent said indicating means from substantially tilting due to forces exerted thereon by said spring member forming part of the second enclosure volume control means.

19. The gauge of Claim 18 wherein said cylindrically shaped extension arm masks at least part of the coils of said spring member forming part of the second enclosure volume control means.

20. The gauge of Claim 17 wherein said groove in said annular collar is cut to a predetermined depth so as to minimize any associated parallax error in reading said gauge.

21. The gauge of Claim 1 wherein said means for indi-cating include at least one band on the outside of said first enclosure forming means.

22. The gauge of Claim 21 including a second band on the outside of said first enclosure forming means, said first band representing one pressure and said second band representing a second different pressure.

23. The gauge of Claim 1 wherein said means for affixing said gauge to said inflatable device include an elongated mounting stem, said mounting stem bent so as to minimize curb interference problems.