1. Field of the Invention
The present invention relates to the field of compressed air and gas systems, and more particularly to tire fill nozzles and tire gauges.
2. Description of Prior Art
Typical compressed air or gas produced by a compressor apparatus is saturated with 50% to 100% relative humidity, and also contains contaminants such as dirt, dust, oil, line debris and other matter. Filters and traps remove liquid water and other contaminants but do nothing to eliminate the 50% to 100% moisture vapor still remaining in the compressed air or gas. The removal of this moisture vapor requires that an air/gas dryer system be used, such as a refrigerated dryer or an adsorbent type of dryer. Such systems are generally very effective, the latter being typically capable of drying compressed air or gas to below-zero dew point levels. However, even basic dryer systems are relatively expensive, can be difficult to install due to their large and bulky nature, and require regular maintenance to ensure proper operation. Individuals and other entities with limited financial resources, or who do not use compressed air/gas on a regular basis, may elect not to install drying equipment in their compressed air/gas systems, and instead use compressed air or gas that has not been treated to remove moisture vapor. Even if a dryer system is installed, there is no guarantee that the compressed air or gas will have the desired dryness by the time it arrives through an air/gas feed system to a downstream point of use. Compressed air lines, various fitting and regulation devices, or improper operation of the dryer system all represent sources of residual moisture vapor in the air/gas feed system. This means that compressed air or gas that has been moisture-treated may not have the desired dryness characteristics by the time it goes into use as an application. This can cause problems in applications such as automotive maintenance where compressed air or gas is used to pressurize tires to a proper pressure level. If moisture-laden ambient air is delivered through the air/gas line, it will feed into the tires, and may cause unwanted pressure variations as the tires heat up during use.
It is to solving the foregoing problems that the present invention is directed. What is particularly needed is an improved air/gas dryer that is easy to install and use for tire filling and pressure monitoring, is simple and inexpensive, and requires no maintenance. The dryer should be suitable for use as the primary or sole air/gas moisture vapor treatment apparatus in a compressed air/gas system, but should also be usable with existing dryer systems. Adding a filtering function to such a dryer would be further desirable.
The foregoing problems are solved and an advance in the art is achieved by a tire fill nozzle having an integrated dryer for drying compressed air or gas delivered to a tire. According to exemplary embodiments disclosed herein, the tire fill nozzle may comprise a main body, an inlet connector on the main body adapted to engage an air/gas line, an outlet connector on the main body adapted to engage a tire valve stem, and a dryer in the main body adapted to dry air/gas passing through the nozzle. The dryer can be provided by a drying composition, such as a desiccant, and can be permanently disposed within the main body or optionally disposed within a replaceable cartridge. The tire fill nozzle may optionally include an integrated dryness indicator. The dryness indicator can be provided by a dryness indicating material, such as a color-changing desiccant. If the dryness indicating material is a color-changing desiccant, it may also serve as the drying composition. The color-changing desiccant may be viewed by providing a transparent or translucent window in the nozzle, or by forming all or a portion of the nozzle with a transparent or translucent material such that the dryness indicating material is visible from outside the nozzle. The dryness indicating material may also be separate from the drying composition, such as by placing the dryness indicating material in a portion of the nozzle that is separate from where the drying composition is situated. The dryness indicating material may also be disposed in a replaceable cartridge that is removably disposed within the main body. The tire fill nozzle may further optionally include an integrated air/gas filter. The inlet connector may optionally comprise a tire valve fitting. The outlet connector may optionally comprise a fitting adapted to threadably engage a tire valve stem. The tire fill nozzle may further optionally include an integrated tire pressure gauge. The tire gauge may comprise an analog or digital display.
The foregoing and other features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying Drawings in which:
a is an inlet end view of the tire fill nozzle of
a is an exploded perspective view of a first alternative dryness indicator for use in the tire fill nozzle of
b is an exploded perspective view of a second alternative dryness indicator for use in the tire fill nozzle of
Turning now to the drawings wherein like reference numerals indicate like elements in all of the several views,
The main body 4 is generally tubular in shape and is sized so that it can be comfortably grasped with one hand during use. The dimensions of the main body 4 may correspond to those of conventional tire fill nozzles. For example, the main body 4 may have a shaft length of approximately 6 inches, an outside diameter of approximately ¾ inches and an inside diameter of approximately ½ inches. Other shapes and sizes could also be used. The main body 4 can be constructed using any suitable material capable of safely withstanding the operational pressures normally delivered during tire pressurization, for example, up to approximately 150 psi. Although the main body 4 could be made from brass or other types of metal, a plastic material, such as polyethylene, is preferred. Transparent or translucent plastic is preferred because the transparency or translucency of the material will inherently provide the viewing portion 16 of the main body 4. The remaining portion of the main body 4 may then be coated with a pigment to provide opacity. Alternatively, the entire main body 4 could be left transparent or translucent. Another way to provide the viewing portion 16 would be to mount a transparent or translucent tubular extension onto an opaque member. In that case, the tubular extension could be formed from transparent or translucent plastic and the opaque member could be formed from opaque metal or plastic.
The inlet connector 6 may be provided by a conventional compressed air line fitting made from brass or the like. As shown in
The outlet connector 8 may be provided by a conventional Schrader valve actuator fitting made from brass or the like. As shown in
Within the main body 2, the drying composition 11 occupies a majority of the internal volume. The drying composition 11 can be selected from any suitable material having the required drying characteristics, including but not limited to (1) moisture adsorbing desiccants such as silica gel beads, activated alumina beads, clays and molecular sieves, and (2) moisture absorbing fibers such as cotton, paper, wood particles or the like. Due to their superior moisture removal properties, silica gel desiccant beads of the type commonly used in compressed air/gas drying systems represent the preferred material used for the drying composition 11. The size of the desiccant beads is selected to minimize unwanted pressure drop within the nozzle 2. The average silica gel bead diameter will preferably lie in a range of about 0.0625-0.25 inches, with a diameter of 0.125 being most preferred. It will be appreciated that increasing the diameter of the silica gel beads tends to reduce the resistance to air/gas flow through the nozzle 2, thereby reducing pressure drop, but also reduces the amount of effective adsorbing surface area. On the other hand, decreasing the size of the silica gel beads increases the amount of adsorbing surface area, but also increases the resistance to air/gas flow, so as to increase the pressure drop through the nozzle 2. The 0.0625-0.25 inch silica gel desiccant beads, when carried within the main body 4 configured with a size of ½ inches inside diameter by 6 inches in length, is capable of delivering a relative humidity of as low as ½% (−40 degree F. dew point) at a flow rate of 20 SCFM, with an inlet pressure of 100 psi and an outlet pressure of 60 psi. As an alternative to desiccant beads, a desiccant block made from silica gel or other desiccant material could also be used. The diameter of the desiccant block may be sized to substantially match the inside diameter of the main body 4, thereby preventing air from passing around the outside of the block.
The drying composition 11 is preferably maintained in a densely packed condition within the main body 4. Proximate to the air inlet end 21 of the main body 4, the drying composition is trapped by an inlet filter 34 that is supported on an internal shoulder 36. The shoulder 36 is formed at the point where the air inlet end 21 connects to the remainder of the main body. The shoulder 36 represents the transition between the smaller diameter of the air inlet end 21 and the larger diameter of the main body proper. It will be seen that the air inlet end 21 is immediately upstream of the inlet filter 34. The central air/gas passage within the air inlet end 21 will thus act as a plenum that distributes the incoming air/gas stream across the face of the inlet filter 34 and the drying composition 11 on the other side thereof, which improves drying efficiency. The inlet filter 34 may be formed from a metal screen or the like and may have an exemplary mesh size of approximately 20 mesh. The opposite end of the drying composition 11 is trapped by an intermediate filter 37. The intermediate filter 37 can be formed by any suitable filtering media, such as a pad filter made from loosely interwoven fibers.
The dryness indicating material 14 may be provided by a suitable color-changing desiccant, including cobalt-based material. This material will have a deep blue color when the air or gas nozzle 2 is dry, thus signifying that the dryer 10 is fully functional. When the dryer 10 is spent and the air or gas loses its dryness, the color of the desiccant will change. For example, a cobalt-based color-changing desiccant will change from its initial deep blue color to light pink or clear, thereby indicating that the filter/dryer needs to be replaced. Other moisture-sensitive visual indicating materials, such as moisture-sensitive paper that turns color according to the surrounding moisture level, could also be used as the dryness indicating material 14.
The dryness indicating material 14 is preferably maintained in a densely packed condition within the viewing portion 16 of the main body 4. One end of the dryness indicating material 14 is trapped by the intermediate filter 37. The other end of the dryness indicating material 14, which is proximate to the air outlet end 30 of the main body 4, is trapped by an outlet filter 38. The outlet filter 38 may be formed from a metal screen or the like and may have an exemplary mesh size of approximately 120 mesh. Alternatively, a double mesh screen having respective mesh sizes of 20 and 120 mesh, could be used. The smaller mesh size of the outlet filter 38 is designed to trap small particulates, such as desiccant dust, and prevent such contaminants from exiting the nozzle 2. As can be seen in
During use, the inlet connector 6 is attached to the end of a compressed air line delivering compressed air or gas. The outlet connector 8 is attached to a tire valve stem to introduce compressed air or gas into a tire in the normal manner. As the compressed air or gas passes through the tire fill nozzle 2, it will contact the surfaces of the drying composition 11. At least some of the moisture carried within the air/gas stream will be adsorbed (or absorbed) by the drying composition 11 and will thereby be removed from the air/gas stream as it exits the intermediate filter 37. The air/gas stream will then pass through the dryness indicating material 14, where its residual moisture level will cause the dryness indicating material to assume a characteristic color. In addition to the air/gas stream being dried, the filters 34, 37 and 38 will serve will provide an integrated filtering function whereby the air/gas stream is filtered and unwanted contaminants are removed therefrom. At the beginning of service of the nozzle 2, the color of the dryness indicating material 14 should indicate that the air or gas passing therethrough is relatively dry. As service life advances, the drying composition 11 will typically tend to lose its drying capability (e.g., if it is a desiccant) due to moisture being adsorbed (or absorbed) thereby. This will result in the moisture level of the air/gas stream gradually increasing, and will cause the dryness indicating material 14 to change color. The changing color of the dryness indicating material 14 will visually indicate the loss of drying capability of the nozzle 2. The tire fill nozzle 2 can be designed to be disposable after the drying composition 11 has been spent, or can be designed so that the dryer 10 can be readily renewed, as described for example in connection with
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Additional manufacturing efficiency may be obtained by placing the drying composition 511 of the dryer 512 within its own cartridge (not shown) which may be constructed in the same fashion as the cartridge 410a shown in
Accordingly, a tire fill nozzle having an integrated dryer has been disclosed for effectively delivering dry and filtered air or gas to a tire filling application. It should, of course, be understood that the description and the drawings herein are merely illustrative, and it will be apparent that various modifications, combinations and changes can be made in accordance with the invention. For example, although the drying composition has been shown in various embodiments to be located separately from the dryness indicating composition, it would be possible to co-mingle these materials to produce a composite dryer/dryness indicator. For example, the dryness indicating composition could be interspersed with the drying composition at a suitable ratio (e.g., four parts drying composition to one part dryness indicating composition), and visa versa. The co-mingled materials could be disposed directly in the main body or in a cartridge that is insertable in the main body. All or a portion of the main body that houses the co-mingled materials could be transparent or translucent to allow observation of the dryness indicating material. As such, the invention is not to be in any way limited except in accordance with the spirit of the appended claims and their equivalents.
This application claims benefit of U.S. Provisional Application No. 60/701,704, filed on Jul. 23, 2005.
Number | Date | Country | |
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60701704 | Jul 2005 | US |