Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation-in-part of U.S. Ser. No. 10/630,090 filed Jul. 30, 2003, which is a continuation of U.S. Ser. No. 10/154,416 filed May 23, 2002 now abandoned . U.S. Ser. No. 10/154,416 claims the benefit of U.S. Provisional Application No. 60/366,676 filed Mar. 22, 2002 and is a continuation-in-part of U.S. application Ser. No. 29/136,877 filed Feb. 8, 2001. U.S. application Ser. No. 29/136,877 issued as U.S. Design Pat. No. D461,196 on Aug. 6, 2002. 

   FIELD OF THE INVENTION 
   The present invention generally relates generally to the field of portable air compressors and more particularly to hand portable air compressors with improved portability and ruggedness. 
   BACKGROUND OF THE INVENTION 
   Small air compressors have become common tools around the home, workshop and work site. For home, recreation and other light duty uses such as inflating sports or recreation equipment or for emergency use in inflating a car tire a number of very small and lightweight compressors are available. Such tasks require relatively low-pressure compressed air and/or relatively low airflow rates. Weight is kept low and portability is maximized in these designs by use of small, low volume and/or low-pressure compressors powered by small lightweight electric motors. Additionally, significant weight, size and cost savings are achieved by the omission of a high-pressure vessel (i.e., air tank), as well as an oil lubrication system. 
   Many jobs, however, require higher air pressures, and/or greater instantaneous air flow demands which typically exceed the capacity of the hobby or recreational use compressors. To satisfy the demands of higher air pressure and higher airflow tasks it is necessary to increase the size of the compressor and the related motor or engine. Furthermore, rather than sizing the compressor to meet the maximum theoretical instantaneous air flow demand, it is common design practice to include a compressed air reservoir in the form of an air tank or other pressure vessel. The tank, usually with an output regulator, can hold a quantity of pressurized air to meet peak demands from serviced loads, while allowing the use of a smaller and lighter compressor that charges the tank and is capable of meeting the average compressed air flow rate for the intended use. 
   The air tank and the larger compressor that are typically required to meet the desired pressure and airflow levels substantially increase the weight and overall size of the compressor package. Units designed for high pressure and high volume tasks can rapidly reach a weight and size where the well-known motor vehicle mounted or towed trailer configuration is the only practical form. Still, there are a range of intermediate capacity air compressors that are common tools around the construction site and which are man portable. 
   Current models of man portable air compressor packages comprise a stand or supporting structure on or in which are mounted a motor or engine, an air compressor, an air tank, a discharge manifold and various valves, instrumentation and controls. Many of the larger portable configurations are provided with wheels, in what is often referred to as a wheelbarrow configuration, so that they can be moved by a single user. Examples of wheeled air compressors include Models D55170 and D55270, which are marketed by DeWalt. 
   Still, some users of intermediate capacity professional grade compressors find it necessary or desirable to have a compressor that is capable of being lifted and carried by hand. One common approach taken by air compressor manufacturers to improve the portability of such intermediate capacity professional grade compressors has been to redesign the air compressor so as to reduce its weight. Despite such efforts, intermediate capacity professional grade compressors frequently weigh more than 50 pounds and thus remain difficult to lift and move by hand, even for those users who are physically strong. 
   Aside from the issue of their weight, hand-portable intermediate capacity professional grade compressors are also known to be quite cumbersome to transport. In this regard, the configurations that use two cylindrical tanks or a single pancake tank (i.e., a cylindrical tank of large diameter but small height with convex ends) have become common, as have the mounting schemes for mounting the compressor and the motor. For example, configurations that use two cylindrical tanks typically mount the compressor and motor alongside the tanks, whereas configurations that use a single pancake tank typically mount the compressor and motor on an end of the tank. 
   These conventional air compressor arrangements provide a package with a relatively large base or footprint, and a center of gravity that is positioned in an approximately centered position within the footprint. While such arrangements provide the air compressor with a configuration that is relatively stable during its operation, lifting and carrying air compressors with these configurations tends to be rather awkward and difficult. In this regard, these configurations typically employ a handle (for lifting and carrying the air compressor) that is attached to an appropriate structure, such as the stand or the air tank, at a location that is located vertically above the center of gravity of the entire air compressor package. The handle is generally oriented in a manner that requires the air compressor package to be lifted vertically upwards and carried in an orientation that is substantially the same as the orientation in which it is operated. 
   Lifting and carrying the known intermediate air compressor packages in this manner, however, is relatively difficult, since the footprint of these air compressor packages tends to be relatively large and thus requires the user to hold the air compressor package with a somewhat outstretched arm such that the wrist of the user is in a state of flexion. In an effort to bring the air compressor package&#39;s center of gravity closer to the central axis of the user, the user will typically tilt their upper body away from the load of the air compressor package and thus will lift and transport the air compressor package with a body posture that is uncomfortable and awkward. 
   SUMMARY OF THE INVENTION 
   In one form, an air compressor is provided with improved portability. The air compressor includes a compressor, a support structure and at least one air tank in fluid connection with the compressor. A handle extends outwardly from a side of the compressor assembly and is configured to be grasped by a hand of a user so that the air compressor can be rotated about a horizontal axis between an operating position and a hand-carried transport position. The air compressor further includes at least one protective stop configured to contact a surface which supports the compressor assembly in the operating position when the compressor assembly is moved between the operating position and the transport position. 
   In another form, the air compressor may include two laterally spaced apart air tanks; a compressor disposed between the two air tanks and in fluid connection with each of the air tanks; and two inverted unshaped tubular members extending upwardly from the two air tanks, where the two u-shaped tubular members are laterally spaced apart such that the compressor is disposed substantially within a volume defined by the u-shaped tubular members and the air tanks. The air compressor further includes a handle projecting outwardly in a horizontal direction away from the compressor; and at least one rubber member affixed to an outwardly facing surface of the air tank disposed opposite the handle, such that the rubber member prevents slippage of the air compressor assembly away from the user when the compressor assembly is moved between the operating position and the transport position. 
   Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a compressor package constructed in accordance with the teachings of the prior art; 
       FIG. 2  is a front view of a user transporting the compressor package of  FIG. 1 ; 
       FIG. 3  is a perspective view of an air compressor package constructed in accordance with the teachings of the present invention; 
       FIG. 4  is a left side elevational view of the air compressor package of  FIG. 3  as positioned in an operational position; 
       FIG. 5  is a rear elevational view of the air compressor package of  FIG. 3 ; 
       FIG. 6  is a bottom plan view of the air compressor package of  FIG. 3 ; 
       FIGS. 7A and 7B  are left side elevational views of the air compressor package of  FIG. 3  as its being rotated to and positioned in a transport position, respectively; 
       FIG. 8  is a perspective view of an air compressor package constructed in accordance with the teachings of an alternate embodiment of the present invention; 
       FIG. 9  is a left side elevational view of the air compressor package of  FIG. 8  as positioned in a transport position; 
       FIG. 10  is a perspective view of an air compressor package constructed in accordance with the teachings of another alternate embodiment of the present invention; 
       FIG. 11  is a left side elevational view of the air compressor package of  FIG. 10  as positioned in an operational position; 
       FIG. 12  is a top plan view of the air compressor package of  FIG. 10 ; 
       FIG. 13  is a bottom plan view of the air compressor package of  FIG. 10 ; 
       FIG. 14  is a rear elevational view of the air compressor package of  FIG. 10 ; and 
       FIGS. 15A and 15B  are left side elevational views of the air compressor package of  FIG. 10  as its being rotated to and positioned in a transport position, respectively. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   With reference to  FIGS. 1 and 2  of the drawings, a prior art air compressor package  1  is illustrated to include a support structure  2 , a compressor mechanism  3 , an air tank  4  and a handle  5 . The compressor mechanism  3  and the air tank  4 , which are among the heavier components of the air compressor package  1 , are distributed horizontally about the support structure  2  such that the center of gravity  6  of the air compressor package  1  is disposed well within the interior of an area bounded by the support structure  2 . The handle  5  is coupled to the support structure  2  in a manner that places a centerline  7  of the handle  5  vertically in-line with the center of gravity  6  of the air compressor package  1 . 
   With additional reference to  FIG. 2 , the configuration of the handle  5  is such that it permits the air compressor package  1  to be lifted vertically and transported in the same orientation as it is operated. The size of the footprint or base  8  of the air compressor package  1 , however, is relatively large, which necessitates that the user  9  transport the air compressor package  1  with a somewhat outstretched arm  9   a . Consequently, the user&#39;s wrist  9   b  is maintained in a state of flexion, which tends to be uncomfortable for the user and fatiguing. 
   In  FIGS. 3 through 5 , an air compressor package constructed in accordance with the teachings of the present invention is generally indicated by reference numeral  10 . The air compressor package  10  is illustrated to include a compressor mechanism  12 , an air tank  14 , a support structure  16 , a handle  18  and a gauge package  20 . The compressor mechanism  12  is conventional in its construction and operation and as such, need not be discussed in detail herein. Briefly, the compressor mechanism  12  includes a compressor  22 , which is operable for intaking and compressing ambient air, and a power source, such as an electric motor  24  or an engine, for providing power to the compressor  22 . The compressed air that exits the compressor  22  is discharged to the air tank  14 , which serves as a reservoir for the compressed air. 
   The air tank  14  has a capacity of at least 0.5 gallons and in the particular example provided, is illustrated as having a single cylindrically shaped tank structure. The air tank  14 , however, preferably has a capacity of about 1 to about 8 gallons, and more preferably a capacity of about 3 to about 5 gallons. Those skilled in the art will understand that the air tank  14  may be configured somewhat differently, as with a conventional pancake-style (i.e., a relatively short and large diameter cylinder with convex ends) tank structure (not shown) or with a plurality of cylindrically shaped tank structures that are coupled in fluid connection. 
   The support structure  16  is illustrated to be configured in a “roll-cage” manner that extends around both the compressor mechanism  12  and the gauge package  20  to protect these components should the air compressor package  10  be overturned or impacted by another object. In the particular embodiment illustrated, the support structure  16  includes a tubular frame  30  having opposite laterally extending sides  32  that are interconnected by a mounting platform  34  and a plurality of strut members  36 , as well as an optional shield or cover  38 . In the example provided, the cover  38  is formed from a sheet material, such as steel, aluminum or plastic, and is removably fastened with, for example, conventional threaded fasteners (not shown) to the tubular frame  30 . While the primary purpose of the cover  38  is to protect components such as the compressor mechanism  12  and the gauge package  20  from damaging contact with, for example, falling tools and workpieces, those skilled in the art will understand that the relatively smooth outer surface of the cover  38 , when abutted against the lateral side of the user during transport, is relatively more comfortable and less likely to interfere with the movement of the user as compared to the tubular frame  30 , the compressor mechanism, the air tank  14  and/or the gauge package  20 . 
   In the example provided, the laterally extending sides  32  are constructed in an open manner, such that the ends  42  of the laterally extending sides  32  do not intersect one another but rather intersect the air tank  14 . The ends  42  are coupled to the air tank  14  through a conventional coupling means, such as welds. In the particular embodiment illustrated, the air tank  14  extends through the laterally extending sides  32  but those skilled in the art will understand that the air tank  14  could alternatively be configured to terminate flush or inboard of the laterally extending sides  32  so that the support structure  16  would also protect the opposite ends of the air tank  14 . The gauge package  20 , which conventionally includes an air tank pressure gauge  46 , a regulator  48 , a regulator gauge  50  and an outlet manifold  52 , is coupled to a gauge panel  54  that is mounted between the laterally extending sides  32  of the support structure  16 . The gauge panel  54  may be a discrete component or may be integrally formed with the cover  38 . Preferably, the gauge panel  54  is mounted in a rearwardly sloped orientation, which is best illustrated in  FIGS. 3 and 4 , as opposed to the substantially vertical orientation that is illustrated in the prior art air compressor package  1  of  FIG. 1 , so as to position the air tank pressure gauge  46 , the regulator  48 , the regulator gauge  50  and the outlet manifold  52  in a manner that is relatively more comfortable for the user of the air compressor package  10  to read and/or access. As those skilled in the art will appreciate from this disclosure, the improved readability of the air tank pressure gauge  46  and the regulator gauge  50  and the improved accessibility of the regulator  48  that result from the positioning of the gauge panel  54  in a rearwardly sloped orientation improves the accuracy with which the user is able to control the air pressure that is delivered to the outlet manifold  52 . Pegs  58 , which are coupled to one of the laterally extending sides  32  and extend outwardly therefrom, are optionally provided so as to permit items, such as a power cord  60  or an air hose  62 , to be coiled (around the pegs  58 ) for storage. 
   The mounting platform  34 , which is illustrated to be fabricated from a sheet material, such as steel, aluminum or plastic, serves as the base  66  of the support structure  16 . The compressor mechanism  12  is coupled to the mounting platform  34  via a plurality of threaded fasteners (not specifically shown). A plurality of rubber feet  68  are affixed to the corners of the mounting platform  34  and serve to dampen vibrations that are transmitted through the support structure  16  as well as to provide the support structure  16  with a degree of skid resistance. With specific reference to  FIG. 6 , an access aperture  70  is formed through the mounting platform  34  and permits the user to access a valve mechanism  72  to manually drain the air tank  14 . 
   With renewed reference to  FIG. 4 , those skilled in the art will appreciate that the air tank  14  and the compressor mechanism  12  are coupled to the support structure  16  such that their centers of gravity, CG AT  and CG AC , respectively, are positioned relatively close to the base  66  when the air compressor package  10  is oriented in its operational position ( FIGS. 3 through 5 ). As the air tank  14  and the compressor mechanism  12  account for a majority of the weight of the air compressor package  10 , configuration in this manner is advantageous in that it provides the air compressor package  10  with a relatively low center of gravity CG ACP . As those skilled in the art will understand, the center of gravity CG ACP  acts along a plane  80  that is skewed to the base  66 . In the particular embodiment illustrated, the plane  80  is substantially perpendicular to the base  66  since the base  66  is situated on a flat surface  82 , such as a floor. 
   With reference to  FIGS. 3 and 7 , the handle  18  is configured to be gripped by a palmar surface  90  of the hand  92  of a user  94  when the user  94  is transporting the air compressor package  10 . The handle  18  may be of any type and may be mounted to any appropriate structure, such as the support structure  16  or the air tank  14 . In the particular embodiment illustrated, the handle  18  is fixedly mounted to air tank  14  and includes a grip portion  96  that is contoured to receive the fingers of the user when the user is transporting the air compressor package  10 . The grip portion  96  is formed about a centerline  98  that lies in (or is positionable into) a plane  100  that includes the center of gravity CG ACP  of the air compressor package  10 . 
   The handle  18  permits the user of the air compressor package  10  to reposition the air compressor package  10  from the operational position that is illustrated in  FIG. 4  to a transport position that is illustrated in  FIG. 7A . To facilitate repositioning of the air compressor package  10  in this manner, a protective stop  69  may be fastened with, for example, conventional threaded fasteners (not shown) to each of the laterally extending sides  32  of the tubular frame  30 . The protective stops  69  are preferably comprised of rubber or some other type of material having an adhesive characteristic. In some instances, the user may roll air compressor package onto its side as shown in  FIG. 7B . In these instances, the protective stops  69  prevent any unwanted slippage of the air compressor package away from the user. 
   When positioned in the transport position, the plane  100  that includes the centerline  98  of the handle  18  and the center of gravity CG ACP  of the air compressor package  10  is located in a substantially vertical orientation that is generally parallel to a vertical (longitudinal) axis  104  of the user  94 , as well as generally parallel to the base  66  and the top  108  of the air compressor package  10 . 
   Furthermore, since the center of gravity CG ACP  of the air compressor package  10  is relatively close to the base  66  when the air compressor package  10  is oriented in the operational position, the user  94  is able to transport the air compressor package  10  such that the base  66  is proximate a lateral side  110  of the user  94  (i.e., within about 10 inches of the lateral side  110 , and preferably about 3 inches to about 7 inches) and the user&#39;s wrist  112  is not in a state of flexion. When placed in the transport position, the air compressor package  10  is preferably configured such that the centers of gravity CG AT  and CG AC  of the air tank  14  and the compressor mechanism  12  are disposed in the plane  100 , or oppositely offset therefrom by substantially equal distances. With the handle  18  thus positioned, the user  94  is able to comfortably carry the air compressor package  10 , as well as to easily pivot the air compressor package  10  between the operational position and the transport position without releasing the handle  18 . 
   While the air compressor package  10  has been described thus far as including an air tank  14  with a single cylindrically shaped tank structure and a handle  18  that is fixedly coupled to the air tank  14 , those skilled in the art will appreciate that the invention, in its broader aspects, may be constructed somewhat differently. For example, the handle  18   a  may be incorporated into the support structure  16   a  as illustrated in  FIGS. 8 and 9 . In this embodiment, the support structure  16  extends around the air tank  14  on a side opposite the compressor mechanism  12  and upwardly from the base  66 . A grip structure  96   a  is formed on the front strut member  36   a  that interconnects the opposite laterally extending sides  32   a . Like the handle  18  of the air compressor package  10  that is illustrated in  FIG. 3 , the handle  18   a  is positioned such that a centerline  98   a  of the grip structure  96   a  is positioned in a plane that contains the center of gravity CG ACP  of the air compressor package  10   a  when the air compressor package  10   a  is positioned in the transport position. 
   An alternative arrangement for an air compressor package  120  constructed in accordance with the teaching of the present invention is depicted in  FIGS. 10–14 . In this embodiment, an air compressor mechanism  122  is mounted between a pair of cylindrically shaped air tanks  124 . As shown, the air tanks are spaced apart laterally from each other and supported on the underside by a pair of skid bars  126 . The skid bars  126  are likewise spaced apart laterally from each other, but mounted transversely to the two air tanks  124 . A rubber foot  128  is affixed to each end of each skid bar  126 . These rubber feet  128  serve to dampen vibrations that are transmitted through the support structure during operation as well as provide a degree of skid resistance when placed in an operational position. 
   As described above, the air compressor mechanism  122  further comprises a compressor  132  operable to intake and compress ambient air and a power source  134 , such as an electric motor or an engine, for providing power to the compressor. The compressor mechanism is again of a conventional construction and operation and as such does not need to be described in further detail. 
   A shroud assembly  140  protects the compressor mechanism and associated components should the air compressor package  120  be overturned or impacted by another object. In an exemplary embodiment, the shroud assembly  140  includes a protective plate  142  extending between a pair of inverted u-shaped tubular members  144 . Ends of the tubular members  144  are coupled by conventional means, such as welds, to the top surface of the air tanks  124 . The protective plate is in turn coupled to the tubular members  144 . The protective plate is formed from a sheet or material, such as steel, aluminum, plastic or other suitable material, and is removably fastened with, for example, conventional threaded fasteners to the tubular frame. 
   A portion of the protective plate serves as a gauge panel  146  which supports conventional compressor accessory components, such as pressure gauges, a pressure regulator and one or more outlet manifolds. The gauge panel  146  is preferably sloped rearwardly in a manner that improves readability and accessibility of the gauges housed in the panel. 
   To transport the air compressor package  120 , a handle extends outwardly from either side of the air compressor package  120 . In the exemplary embodiment, the handle  150  is a tubular member which extends between the two u-shaped tubular members  144 . It is contemplated that the handle  150  may include a grip portion that is contoured to receive the user&#39;s fingers. It is also contemplated that the handle may have other configurations and be mounted to other appropriate support structure, such as one of the air tanks. Again, the grip portion is preferably formed about a centerline that lies in (or is positionable into) a plane that includes the center of gravity CG ACP  of the air compressor package  120 . The handle  150  enables the user to rotate the air compressor package  120  to an intermediate position as shown in  FIG. 15A  prior to reaching a transport position as shown in  FIG. 15B . 
   Protective stops  152  are again used to prevent any unwanted slippage of the air compressor package away from the user. In this embodiment, the protective stops  152  are fastened to the air tank disposed on an opposite side from the handle  150 . More specifically, the protective stops  152  are fastened to a mounting bracket  154  which in turn is coupled to the air tank by conventional means, such as welds, as best seen in  FIG. 14B . The protective stops  69  are preferably comprised of rubber or some other type of material having an adhesive characteristic. The protective stops  152  also protect the air tank from the rough surface and/or abrupt landings which may be encountered as the air compressor package is returned to an operational position. 
   When positioned in the transport position, the plane  160  that includes the centerline  162  of the handle  150  and a center of gravity CG ACP  of the air compressor package  120  is located in a substantially vertical orientation that is generally parallel to a vertical (longitudinal) axis  104  of the user  94 , as well as generally parallel to a base and a top  108  of the air compressor package  120 . Furthermore, since the center of gravity CG ACP  of the air compressor package  120  is relatively close to the base when the air compressor package  120  is oriented in the operational position, the user  94  is able to transport the air compressor package  120  such that the base is proximate a lateral side  110  of the user  94  (i.e., within about 10 inches of the lateral side  110 , and preferably about 3 inches to about 7 inches) and the user&#39;s wrist  112  is not in a state of flexion. With the handle  150  thus positioned, the user  94  is able to comfortably carry the air compressor package  120 , as well as to easily pivot the air compressor package  120  between the operational position and the transport position without releasing the handle  150 . 
   While the invention has been described in the specification and illustrated in the drawings with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention as defined in the claims. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment illustrated by the drawings and described in the specification as the best mode presently contemplated for carrying out this invention, but that the invention will include any embodiments falling within the foregoing description and the appended claims.

Technology Category: 2