Abstract:
A portable air compressor includes a frame, a motor mounted to the frame, a storage tank coupled to the frame and a compression mechanism in communication with the storage tank. The motor drivingly engages the compression mechanism. The compressor includes a first regulator coupled to the storage tank for defining a first pressure at a first outlet port. A second regulator is coupled to the storage tank for defining a second pressure output at a second outlet port.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/262,304, filed Jan. 12, 2001. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates generally to air compressors and, more particularly, to a portable air compressor having individual high and low pressure output ports. 
     2. Discussion 
     Construction workers and other professionals often times have a need for a portable compressed air source. Specifically, workers within the rough construction industry have found certain tools such as air nailers and air staple guns useful in their trade. To operate these devices in the field, a portable source of compressed air is required. Additionally, it should be appreciated that many construction sites do not include a source of electrical power. Accordingly, a portable air compressor with its own source of compressing power is preferred. 
     In the past, portable air compressors have been equipped with at least one storage tank having a pressure switch to define the pressure within the tank and a regulator to limit the pressure released at an output port or ports. Typically, the operating range of the output pressure regulator is from 0 to 200 PSI. This corresponds to the operating range of standard air nailers and air staple guns. 
     Recently, a new line of pneumatic hand tools has been introduced. Some air nailers and staple guns now operate at a pressure of approximately 425 PSI. Designers of these new tools have been able to drastically decrease the size and weight of the air nailers using the higher operating pressure. As would be expected, workers in the field prefer lighter weight, less cumbersome tools if performance is not sacrificed. 
     However, many existing air tools currently require regulated pressures ranging from 35 TO 90 PSI. Such devices include paint spray guns and impact wrenches. Accordingly, a need exists for a portable air compressor having a low pressure output port and a high pressure output port. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view of a high pressure portable air compressor constructed in accordance with the teachings of the present invention; 
     FIG. 2 is a partial exploded perspective view of a first panel assembly of the present invention; 
     FIG. 3 is a partial exploded perspective view of an alternative embodiment compressor including a dual pressure limit switch; 
     FIG. 4 is a partial exploded perspective view of a second panel assembly of the present invention; and 
     FIG. 5 is an exploded perspective view of an alternative compressor embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to the figures, a high pressure portable air compressor constructed in accordance with the teachings of the present invention is generally depicted at reference numeral  100 . Air compressor  100  includes a motor  102 , a compressor  104 , a storage tank  106 , a deck  108 , a first panel assembly  110  and a second panel assembly  112 . Deck  108  is coupled to storage tank  106  and includes mounting provisions for motor  102  and compressor  104 . 
     Deck  108  is a generally “U” shaped member having a mounting plate portion  114  positioned between a pair of downwardly extending side walls  116 . Mounting plate portion  114  includes a plurality of apertures  118  for receipt of fasteners (not shown) used to couple motor  102  and compressor  104  to deck  108 . Once mounted to deck  108 , motor  102  is drivingly coupled to compressor  104  via a belt  119 . During operation, rotation of motor  102  causes rotation of compressor  104  thereby initiating a supply of compressed air to an intake port  120  located on storage tank  106 . It should be appreciated that motor  102  may be an electrically powered AC or DC motor, an internal combustion engine or any other suitable power generating device. 
     With reference to FIG. 2, first panel assembly  110  includes a panel  122  coupled to deck  108 . Panel  122  includes a pair of apertures  124  for receipt of a first gage  126  and a second gage  128 . Panel  122  further includes an aperture  130  for receipt of a pressure regulator assembly  132 . A pair of apertures  134  are each adapted to receive a quick coupler  136 . Each quick coupler  136  is a normally closed valve which opens upon interconnection with a mating hose coupler (not shown). Each quick coupler  136  includes a right-hand NPT thread at one end and an automotive type quick connect fitting at the opposite end. Each quick coupler  136  is coupled to a manifold  138  downstream of regulator  132 . Therefore, the output pressure from each quick coupler  136  substantially matches the regulated air pressure. 
     Manifold  138  includes an input  140  receiving pressurized air directly from storage tank  106 . First gage  126  directly receives air stored in storage tank  106  as well. Accordingly, first gage  126  displays storage tank internal pressure. Second gage  128  is also plumbed to manifold  138  but receives regulated pressure downstream of regulator  132 . As such, second gage  128  displays the pressure output from regulator  132 . A pressure relief valve (not shown) is coupled to manifold  138  to assure that only relatively low pressure is available to quick coupler  136 . 
     A pilot valve  142  is also coupled to panel  122  and manifold  138 . Pilot valve  142  is useful to vent compressed air to atmosphere once the target tank pressure is met. It should be appreciated that pilot valve  142  may be alternatively coupled directly to tank  106 . Pilot valve  142  is typically used only when compressor  100  is equipped with an internal combustion motor to allow the internal combustion motor to operate in a constant-run mode. If an electric motor is used, compressor  100  operates in start-stop mode where a pressure limit switch shuts off the motor once the desired tank pressure is reached. 
     A dual control system may also be used in conjunction with an electric motor. The dual control system includes a pressure limit switch and a pilot valve. With dual control, a user may select to operate the compressor in the start-stop mode or the constant-run mode to conserve electricity. 
     In the embodiment depicted in FIG. 3, a dual pressure limit switch  143  is included to allow a user to select a desired maximum tank pressure. If a maximum pressure of 200 PSI is desired, the user simply moves switch  143  to position A. If high pressure tools are to be used, the user moves switch  143  to position B thereby directing motor  102  to compress air until approximately 425 PSI is generated. Therefore, air is compressed to the full 425 PSI only when necessary to avoid undue motor and compressor loading. 
     With reference to FIG. 4, second panel assembly  112  includes a manifold  144  having an input  146  in communication with the interior volume of storage tank  106 . A burst hose  148  is plumbed between manifold  144  and storage tank  106  to prevent gross over-pressure situations. Specifically, burst hose  148  is designed to provide a pressure relief for tank  106  when internal pressure is greater than approximately 900 PSI. 
     Second panel assembly  112  includes a regulator assembly  150 , a gage  152  and a pair of high pressure quick couplers  154 . Gage  152  is positioned downstream of regulator  150  and displays the regulated output pressure. It should be appreciated that second panel assembly  112  is preferably a high pressure panel assembly. As such, pressure gage  152  is capable of measuring pressures up to 450 PSI or greater, if so desired. First gage  126  is therefore the low pressure gage and includes a dial face indicating that pressures from 0-200 PSI are available. 
     With reference to FIG. 1, deck  108  includes a plurality of apertures  155  for receipt of pressure regulator  150 , pressure gage  152  and quick couplers  154 . Each quick coupler  154  includes left-hand NPT threads and preferably includes quick connect fittings of a smaller size than quick couplers  136  to assure that a user connects to the appropriate air pressure source. Manifold  144  is coupled to deck  108  and preferably positioned between the deck and storage tank  106 . In this manner, the high pressure fitting interconnections are not easily disturbed. 
     A second embodiment high pressure air compressor  156  having alternative tank, deck and motor configurations is depicted in FIG.  5 . Air compressor  156  includes a pair of tanks  158  positioned adjacent one another to provide a low-profile assembly. Tanks  158  are plumbed in communication with one another and are charged to the same pressure. Handles  160  are coupled to the tank to assist a user when transporting the air compressor. A wheel  162  is rotatably coupled to tanks  158  to further facilitate movement of the unit. An internal combustion engine  164  is used to drive compressor  104  via drive belts  166 . One skilled in the art will appreciate that a high pressure portable air compressor may be constructed using some or all of the exemplary components depicted in FIG. 5 without departing from the scope of the present invention. The foregoing discussion discloses and describes merely exemplary embodiments of the present invention.