Abstract:
A fluid manifold usable with a welder and air compressor combination. The manifold is constructed of a single unitary manifold block and which is divided into two separate fluid communication systems that are isolated from each other by the manifold block itself. Each of the separate fluid communications systems provides various channels and external ports to access those fluid channels to enable the welder and air compressor combination to be more easily assembled and constructed by locating the manifold in a convenient location within the welder and air compressor combination and which has the necessary fluid channels and conduits already formed within the manifold so that the manufacturer or assembler can simply affix the proper fluid lines and system components to the manifold in carrying out the construction of the welder and air compressor combination and be assured that the proper fluid communication will be achieved.

Description:
BACKGROUND OF INVENTION 
   The present invention relates generally to combined welder and compressor units, and more particularly to a unit of this type having a manifold that is provided in order to facilitate the construction of the welder unit by readily enabling the connection of various fluid lines. 
   Portable welding and compressor units transportable to a work site are known. Typical known units include a lightweight frame consisting of metal tubing on which is mounted an internal combustion engine that is directly connected to a generator which generates an amperage to operate the unit or welder. The generator further provides auxiliary alternating current for operating auxiliary equipment, such as an air compressor. The air compressor provides compressed air for pneumatic equipment as well as certain welding applications, such as operating a plasma cutting torch. Other known portable welder and compressor units include an engine, alternator, compressor, and air tank assembly mounted within a housing along an extended length of the housing. 
   In such welder and air compressor units, there are, of necessity, a considerable number of components that are utilized, some of which are used to channel the main compressed air from the air compressor to desired locations and others that are used to monitor the condition of the compressed air in order to carry out certain operations or to monitor and/or control certain functions of the welder compressor unit itself. In the normal channels of commerce, many of such components are supplied separately and it is up to the constructor of the combination unit to assemble and provide fluid communication for each of such components in an manner that minimizes the time and material of such construction. 
   As such, one of the difficulties in constructing or assembling a compact, readily transportable welder compressor unit, is in interconnecting a large myriad of fluid conduits of differing sizes and purposes so as to make the overall welder compressor combination unit easier to assembly and to locate many of the various fluid conduits in a single, convenient location rather than have individual connections spread throughout the combination unit. Not only is the assembly time reduced but the overall unit is easier to service since many of the connections needed for servicing the combination unit are conveniently at one location. 
   Therefore, one of the main goals in the construction of a welder air compressor combination unit is in facilitating the assembly and mounting of the various components and to make the fluid connections between such components as simple as possible and preferably centrally and conveniently located to facilitate that construction so as to simplify the servicing of such units and to make the combination welder air compressor compact so as to be readily transportable from one location to another location. 
   SUMMARY OF INVENTION 
   The present invention is directed to an improved fluid manifold that is particularly adapted to be used with a welder and air compressor combination to facilitate the connection of the numerous fluid conduits needed for the various components used with such combination unit. 
   In the preferred embodiment, and as will be specifically described herein, the present manifold will be described and illustrated as being used with a welder and air compressor combination, however, it will become clear that the present manifold may be used with a wide variety of other apparatus and equipment to carry out its function of providing a convenient and central location for making certain of the fluid connections needed in the welder air compressor combination unit. 
   Thus, with the present invention, a manifold is provided that comprises a single unitary manifold block and which is divided into two separate fluid communication systems that are isolated from each other by the manifold block itself. Each of the separate fluid communications systems carries out the task of providing various channels and external ports to access those fluid channels to enable the welder and air compressor combination to be more easily assembled and constructed by locating the manifold in a convenient location within the welder and air compressor combination and which has the necessary fluid channels and conduits already formed within the manifold so that the manufacturer or assembler can simply affix the proper fluid lines to the manifold in carrying out the construction of the welder and air compressor combination and be assured that the proper fluid communication will be achieved. 
   In accordance with the preferred aspect of the present invention, an engine-driven welder and air compressor combination is disclosed and includes a compressor that provides a stream of compressed air laden with oil. An oil separator is provided mounted adjacent to the welder and air compressor combination and receives the oil laden stream of compressed air from the air compressor and separates that oil laden stream into an pressurized air stream and a separated oil source. A coalescing filter receives the compressed air from the oil separator and removes further of that oil from that stream of air. The compressed air can be used for some pneumatic equipment use and the separated oil can then be collected and reused as a lubricant and cooling medium within the combination. A manifold is provided that includes a first fluid communication system to channel the compressed air from the oil separator to a conduit leading into the coalescing filter and a second fluid communication system to channel the return flow of compressed air from the coalescing filter to an outlet in the manifold to be communicated, ultimately, to the pneumatic equipment. 
   In accordance with yet another aspect of the present invention, a welding and air compressor combination includes a manifold that comprises a unitary manifold block such that the fluid in the first fluid communication system and the fluid in the second fluid communication system are fluidly separated from each other. In addition, the manifold of the present invention has a number of auxiliary ports for mounting various components that are used in the control and functioning of the overall welder and air compressor combination. 
   Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings. 

   
     BRIEF DESCRIPTION OF DRAWINGS 
     The drawings illustrate one preferred embodiment presently contemplated for carrying out the invention. 
     In the drawings: 
       FIG. 1  is a perspective view of a welder and air compressor combination incorporating the present invention. 
       FIG. 2  is a perspective view of a portion of the welder and air compressor combination with a housing cover removed. 
       FIG. 3  is a side view of the welder and air compressor combination of FIG.  2 . 
       FIG. 4  is a perspective view of the fluid manifold constructed in accordance with the present invention. 
       FIG. 5  is a schematic view of the present manifold showing the various ports and internal passageway within the manifold. 
       FIG. 6  is a side, cross sectional view of the manifold of the present invention. 
       FIG. 7  is a lateral cross sectional view of the manifold taken along the line  7 — 7  of FIG.  6 . 
       FIG. 8  is a lateral side cross sectional view taken along the line  8 — 8  of FIG.  6 . 
       FIG. 9  is a lateral side cross sectional view taken along the line  9 — 9  of FIG.  6 . 
       FIG. 10  is a schematic view of the welder and air compressor combination oil and compressed air system showing the manifold of the present invention used therein. 
   

   DETAILED DESCRIPTION 
   Referring now to  FIG. 1 , a portable engine-driven welder and air compressor combination or system  10  is provided and, for brevity, will hereinafter be sometimes referred to as the welder combination  10 . The welder combination  10  has an outer housing  12  that has one or more air vents  14  for cooling internal components of the welder combination  10 . The housing  12  can be easily removed to permit access to the internal components for maintenance and service. A plurality of support members  16  provide stabilization for the welder combination  10  when placed on a generally level surface, such as surface  18 . An upper surface  20  of the welder combination  10  includes a lifting hook  22  extending therethrough for lifting and transporting of the welder combination  10 . Also attached to the upper surface  20  is an exhaust system  24  that lowers noise and removes exhaust gas from the welder combination  10 . 
   The welder combination  10  includes a control panel  26  that has various control elements and gauges for operating the welder combination  10 . A plurality of gauges  28  measure various parameters of the welder combination  10 . Measured parameters can include oil pressure, fuel level, oil temperature, battery amperage, air pressure, and engine running time of the welder combination  10 . Control panel  26  also has a control dial  30  and an ampere range switch  32  which are used to select a voltage/amperage for welding operations. Process selector switch  34  selects the type of weld output. The weld output is determined by the type of welding process. Examples of weld processes that may be implemented include stick welding, TIG welding, air-carbon arc cutting, and various wire feed processes. Electrical outlets  36  provide power for electrically driven devices, such as saws, drills, etc. Control panel  26  also includes a compressor on/off switch  31  and an engine control switch  33  to independently control the compressor and engine, respectively. 
   The control panel  26  also includes multiple power connections such as a single phase power connect  38 , an optional three-phase power connect  40 , and weld-power receptacles  42 . An optional polarity switch  44  can be used to select the polarity of the weld output. Typical selections include direct current electrode negative, direct current electrode positive, and alternating current. A panel remote switch  46  and remote receptacle  48  select remote control of the welder combination  10  in instances where welding operations are remotely located from the welder combination  10 . Positive  50  and negative  52  battery charge connections are used for battery jumpstart or charging, and are positioned adjacent to a system output or shut-off valve  54 . Upon engaging of the compressor clutch and opening of valve  54 , compressed air is supplied for air assisted carbon arc cutting or to air driven power tools and other pneumatic operations. 
   Referring now to  FIG. 2 , a perspective view of a portion  56  of the welder combination  10  of  FIG. 1  is shown with the housing cover  12  removed. An internal combustion engine  58  is mounted to a frame assembly  64  between a radiator shroud  60  and a lifting eye support member  62 . The engine  58 , in a preferred embodiment, is oil cooled and configured to recirculate engine cooling oil. The lifting eye support member  62  secures to the frame assembly  64  for structural support during lifting of the welder combination  10 . The frame assembly  64  has air vents  14  that permit air flow through the welder combination  10  to cool the internal components. Cross-brace  66  provides structural support for the frame assembly  64 . An electrical generator  67  configured to generate an arc welding current is mounted within the housing  12  of the welder combination  10  and driven by the engine  58 . The welder combination further includes a screw air compressor  68  mounted to the engine  58  that is configured to provide compressed air to the shut-off valve  54  of FIG.  1 . The screw air compressor  68  is fluidly connected to an oil separator  70 , a coalescing filter  72 , which combine to separate oil from an air/oil mixture and a first particle oil filter. 
   The internal combustion engine  58  of the welder combination  10  includes an air intake connected to an intake manifold and engine head  78 . The engine head  78  is mounted to an engine block  80 , which collectively form the engine  58 . A pulley arrangement  82  is bolted to both the engine head  78  and the engine block  80  and includes a fan blade hub  84  rotated by a first drive belt  86 , such as a serpentine belt. The first drive belt  86  further connects to an alternator pulley  88  that drives an alternator  90  by a first crankshaft pulley  92 . A belt tensioner  94  connects to a mounting bracket to maintain tension on a second drive belt  96  that drives the screw air compressor  68  driven by a second crankshaft pulley  108 . 
   Referring now to  FIG. 3 , a side view of the portion  56  of  FIG. 2  is shown. Frame assembly  64  connects to support member  62  which is attached to lifting eye  22 . The internal combustion engine  58  is shown having fan blade hub  84  attached to the engine head  78  as previously discussed with reference to  FIG. 2. A  fan (not shown) is attached to fan blade hub  84  that is housed in the radiator shroud  60 . Engine block  80  has alternator  90  mounted thereto which is driven by the first drive belt  86 . The electrical generator  67  mounts to the engine block  80  and is rotated by the engine  58  to generate the arc welding current used in welding operations. Oil separator  70  is mounted to the frame assembly  64  with a mounting plate  98 . An oil return line  100  of the oil separator  70  connects the oil separator  70  to other equipment, such as a radiator and ultimately back to the air compressor  68  ( FIGS. 1-3 ) for cooling and lubrication thereof. 
     FIG. 4  is a perspective view of the manifold  110  that is used with the present invention and is shown along with oil separator  70  and coalescing filter  72 . In this Figure, the oil separator  70  receives a stream of compressed air laden with oil from the air compressor  68  ( FIGS. 1-3 ) through an inlet (not shown). That stream of compressed air laden with oil passes through the oil separator  70  where the air, separated therefrom is discharged through an oil separator outlet  112  and enters the manifold  110  through a first main inlet port (not shown) in the manifold  110 . The oil that is separated from the stream of compressed air laden with oil and which is, in turn, discharged downwardly from the oil separator  70  to the oil return line  100 . The oil separator  70  is affixed firmly in position to the welder combination  10  by means of the mounting plate  98 . 
   Continuing with the flow of the compressed air, it enters the manifold  110  via the first main inlet (not shown) of the manifold  110  and is channeled through the manifold  110  through a first main passageway and into a first main outlet (not shown) in the manifold  110  and thereafter enters a first fluid conduit  114  where the compressed air, now having most of the oil removed therefrom, flows into an inlet  116  in the coalescing filter  72  where a filter media removes additional oil from that stream of compressed air. 
   The stream of compressed air that is discharged through an outlet (not shown) in the coalescing filter  72  and passes through a second fluid conduit  118  where it returns to a second main inlet (not shown) in the manifold  110  where that stream of compressed air further travels through the manifold  110  through a second main passageway and is discharged from manifold  110  through a minimum pressure valve  120  to an outlet  122  where the stream of compressed air is thereafter communicated to an outlet or other device for supplying the compressed air to an end use device such as pneumatic equipment. The minimum pressure valve  120  maintains a minimum air pressure at the compressor outlet port to assure adequate oil flow for lubrication and cooling of the compressor. 
   As further shown in  FIG. 4 , other components are effectively and efficiently affixed to the manifold  110  including a safety relief valve  124  that is set at some predetermined pressure in excess of the normal pressure conditions of the overall pressure system of the welder combination  10  so that the pressure will be relieved in the event that the pressure exceeds that set value. The pressure relief valve is affixed directly to the manifold  110  by means of an auxiliary port (not shown) and communicates with the flow of the compressed air that passes through the first main passageway in the manifold  110  by means of an auxiliary port that will be later explained. 
   Other components that are used with the present manifold  110  include a pressure gauge sender unit  126  that senses the pressure in the first main passageway in the manifold  110  and provide a electrical signal to a remote pressure display that is indicative of the pressure within the first main passageway. As a further component, there is a minimum pressure switch  128  that also senses the pressure of the fluid flowing within the first main passageway of the manifold  110  and prevents the compressor clutch from engaging if the system pressure is above a preset value. This protects the clutch from excessive wear. With each of the components of the pressure gauge sender unit  126  and the minimum pressure switch  128  there is an auxiliary port formed in the manifold  110 , however, both of those components may be combined so as to be operative from one auxiliary port rather than two as shown in the embodiment of FIG.  4 . 
   There is also a bleed down valve  130  affixed to a further auxiliary port formed in the manifold  110  and which communicates with the second main passageway in the manifold  110  and also a pressure feedback sensor  132  that is also provided that communicates with an air intake controller to control the intake air pressures, that is, if the air present in the system rises, the pressure feedback sensor  132  acts to shut down in the intake air to the air compressor  68  ( FIGS. 1-3 ) and conversely, as the air pressure in the system drops, the pressure feedback sensor  132  makes an adjustment to admit more air into the air compressor  68 . Again that component, the pressure feedback sensor  132  also communicates with the second main passageway in the manifold  110 . 
   Turning now to  FIG. 5 , taken along with  FIG. 4 , there is shown a schematic view of the manifold  110  constructed in accordance with the present invention and, as can be seen, the manifold  110  is a generally elongated unitary manifold block  134  having a longitudinal axis, a first end  136  and a second end  138 , for purposes of explaining the invention, and having a number of bores made therein to carry out the purposes of this invention. As can be seen, the unitary manifold block  134  is a single, unitary, piece of material, preferably metal, and all of the passageways and bores, and ports hereinafter to be described are formed in that unitary piece of material. 
   For purposes of explaining the present invention, the differing surfaces will be referred to as the front surface  140 , rear surface  142 , top surface  142  and bottom surface  144 , however it will be seen that the various ports and functions of the present manifold  110  can be carried out without having the ports in certain specified surfaces of the manifold  110 . 
   Accordingly in  FIG. 5 , the first main inlet port  148  is shown and which is formed by a blind bore cut into the bottom surface  146  of the unitary manifold block  134 , that is, when the first main inlet port  148  is formed, the bore does not pass fully through the manifold block  134 . As such, therefore, the first main inlet port  148  is, in the preferred embodiment, a pipe thread port with a diameter of about ¾ inches so as to receive the male threaded outlet  112  from the oil separator  70  ( FIG. 4 ) and is formed at generally a right angle with respect to the longitudinal axis of the elongated manifold block  134 . As such, the fluid coupling between the manifold  110  and the oil separator  70  is easily accomplished and is convenient to be carried out in the construction of the welder combination  10 . 
   In a similar manner, a bore is made in the rear surface  142  of the unitary manifold block  134  to form a first main outlet port  150  such that, in the preferred embodiment, the longitudinal axis of the first main inlet port  148  and the longitudinal axis of the first main outlet port  150  are spaced about 90 degrees apart in the unitary manifold block  134 . Again it is preferred that the first main outlet port  150  be a ¾ inch pipe thread female connection. A first main passageway  152  is provided to allow fluid communication between the first main inlet port  148  and the first main outlet port  150  so that the fluid entering the first main inlet port  150  from the oil separator  70  ( FIG. 4 ) can pass directly to the first main outlet port  150  in accordance with the explained flow path of the flow streams given with respect to FIG.  4 . 
   Accordingly, there can be seen that there is a first fluid communication system that is provided in the first end  136  of the unitary manifold block  134  that establishes a fluid path from the first main inlet port  148  to the first main outlet port  150  through the first main passageway  152 . In addition, there may be at least one additional auxiliary port formed in the first fluid communication system located at the first end  136  of the unitary manifold block  134 . One of such auxiliary ports is shown as first auxiliary port  154  that is formed along the longitudinal axis of the unitary manifold block  134  in the first end  136  thereof and is oriented generally along the longitudinal axis of the elongated unitary manifold block  134 . A second auxiliary port  156  is also formed in the first end  136  of the manifold block  134  and which also communicates with the first fluid communication system, that is, second auxiliary port  156  sees the pressure within the first main passageway  152 . The second auxiliary port  156  is preferably formed in the front surface  140  of the manifold block  134  and is sized to be a ⅛ the inch pipe thread so that the pressure gauge sender unit  126  can be easily and readily affixed to the manifold  110 . 
   As an option, the may also be another auxiliary port, shown as a third auxiliary port  158  that is also formed in the front surface  140  of the manifold block  134  and which is also preferably a ⅛ inch pipe thread and which communicates with the first main passageway  152  and can be used to locate and affix the minimum pressure switch  128  therein. In a preferred embodiment, however, the third auxiliary port  158  can be eliminated and a tee (not shown) can be used with the second auxiliary port  156  so that both the pressure gauge sender unit  126  and the minimum pressure switch  128  can both be operated from the second auxiliary port  156 , in which case, the third auxiliary port  158  can, obviously, be eliminated and thus results in a manifold block  134  requiring less operations in its construction. 
   In any event, as can now be seen with respect to the first end  136  of the manifold block  134 , the are a number of ports that all are preferably provided with female pipe thread fitting so that the desired components and conduits can easily be affixed to the manifold  110  and the correct fluid communication immediately established, thus the construction of the welder combination  10  is simpler to assemble and the manifold  110  allows the correct fluid communication to be automatically established by the making of simple, easy to install, connections with the various components. As such, the present manifold  110  can carry out considerable of centrally located connections that would otherwise have to be made in a myriad of locations throughout the welder combination  10  and some of which could end up in relatively inaccessible and difficult to reach locations and make the construction, as well as the later maintenance of the welder combination  10 , quite difficult. 
   Taking next, the second end  138  of the manifold block  134 , there is formed a second fluid communication system and which comprises a second main inlet port  160  and a second main outlet port  162  and which can be constructed by a straight bore formed straight through the manifold block  134  such that the second main inlet port  160  and the second main outlet port  162  are coaxially aligned, each of which are ¾ inch female pipe threads. As such, the second main inlet port  160  opens outwardly in the bottom surface  146  of the manifold block  134  and the second main outlet port  162  is formed in the top surface  144  of the manifold block  134 . Accordingly, the second fluid conduit  118  that channels the compressed air from the coalescing filter  72  is connected to the manifold  110  at the second main inlet port  160  where the compressed air passes through the manifold  110  through a second main passageway  164  to the second main outlet port  162  that, in turn, has the minimum pressure valve  120  affixed thereto. Preferably the second main inlet port  160  and the second main outlet port  162  are ¾ inch female pipe thread fittings. 
   As with the first fluid communication system, there is at least one auxiliary port formed in the second fluid communication system and a first auxiliary port  166  is formed in the bottom surface  146  of the manifold block  134  and is, preferably, a ¼ inch pipe thread female fitting. The longitudinal axis of the first auxiliary port  166  is, therefore, parallel to the longitudinal axis of the second main passageway  164  formed in the first end  136  of the manifold block  134 . An auxiliary passageway  168  communicates the fluid between the first auxiliary port  166  and the second main passageway  164  and which is generally formed along the longitudinal axis of the elongated manifold block  134 . The auxiliary passageway  168  can be formed by means of a bore  170  made in the second end  138  of the manifold block  134  and after the auxiliary passageway  168  has been formed, the bore  170  is simply plugged at that second end  138  so that the bore  170  no longer exists in the outer surface of the second end  138 . Thus the bleed down valve  130  can be readily and conveniently affixed into the first auxiliary port  166  of the second end  138  of the manifold block  134 . 
   A second auxiliary port  172  is also provided in the second fluid communication system and opens outwardly into the front surface  140  of the manifold block  134 . That second auxiliary port  172  is preferably a ¼ inch female pipe thread and into which is affixed the pressure feedback sensor  132  easily and conveniently and communicates with the auxiliary passageway  168  of the manifold block  134  and associated with the second fluid communication system. 
   As can now be seen, the first fluid communication system that is located at the first end  136  of the manifold block  134  and the second fluid communication system that is formed in the second end  138  of the manifold block  134  are separate and fluidly isolated systems, that is, there is no fluid communication between the first and second fluid communication systems, since any such communication is blocked by the solid material of the manifold block  134  itself. 
   Turning now to  FIG. 6 , there is shown a side cross sectional view taken along the line  6 — 6  of FIG.  5 . In  FIG. 6 , there can be seen the present manifold  110  comprised of the unitary manifold block  134  having formed therein the first fluid communication system comprising a first main inlet port  148  that receives the compressed air from oil separator  70  ( FIG. 4 ) and a first main outlet port  150  that discharges that compressed air to the coalescing filter  72  and is, therefore, connected to the first fluid conduit  114 . As has been noted, both the first main inlet port  148  and the first main outlet port  150  are threaded and are preferably both ¾ inch pipe thread female connections. As also seen, the first auxiliary port  154  is formed in the first end  136  of the unitary manifold block  134  and is preferably a ½ inch pipe thread fitting. The further second and third auxiliary ports  156 ,  158 , are both formed in the front surface  140  of the manifold block  134  are shown and which are preferably ⅛ inch pipe thread fittings. 
   In the second fluid communication system, located at the second end  138  of the manifold block  134 , there is formed the second main inlet port  160  and the second main outlet port  162  that are coaxially formed therein and which are, as explained, preferable ¾ inch pipe thread fittings. The bore  170  is also seen to be plugged such that there is no communication with the second end  138  to the external environment. The first auxiliary port  166  and second auxiliary port  172  and also formed, respectively, in the bottom surface  146  and the front surface  140  and the auxiliary passageway  168  communicates with the second main passageway  164  intermediate the second main inlet port  160  and the second main outlet port  162 . 
   Turning now to  FIG. 7 , there is shown an end cross sectional view taken along the line  7 — 7  of FIG.  6  and illustrating the first main inlet port  150  as well as the second auxiliary port  156  that are oriented at about 90 degrees with respect to each other. 
   In  FIG. 8 , there is shown an end cross-sectional view taken along the line  8 — 8  of FIG.  6  and illustrating the first main outlet port  150  oriented generally at 90 degrees to the first main inlet port  148  ( FIG. 7 ) and the third auxiliary port  158  that extends outwardly coaxially with the first main outlet port  150 . 
   In  FIG. 9 , there is an end cross sectional view taken along the line  9 — 9  of FIG.  6  and showing the second auxiliary port  172  of the second fluid communication system in the second end  138  of the manifold block  134  as well as the auxiliary passageway  168  formed therein. The second auxiliary port  172  is formed as a ⅛ inch pipe thread fitting. 
   Turning now to  FIG. 10 , there is shown a schematic view of the compressor air and oil routing system  174  utilizing the manifold  110  constructed in accordance with the present invention. The compressor system  174  includes an air filter  176  that directs ambient air to an inlet control valve  178 . Air pressure along line  180  controls the inlet control valve  178 , which regulates air flow into the air compressor  68  of FIG.  2 . The air compressor  68  provides a compressed air/oil mixture along line  182  to the oil separator  70 . A high temperature switch  184  monitors the temperature of the air/oil mixture and is configured to open a contact (not shown) to disable the magnetic clutch assembly  107  of  FIG. 3  if the temperature exceeds a predetermined limit. After passing through the oil separator  70 , oil exits the oil separator  70  and enters a cooling system that includes a thermostat  186  and a radiator  188 . A manually controlled drain valve  190  is supplied to drain oil from the oil separator  70 . The radiator  188  acts as a dual purpose radiator having two cooling chambers. One of the two chambers cools compressor oil and the other chamber cools engine coolant by circulating engine oil therethrough. Collectively, the oil separator  70 , first particle filter  74 , thermostat  186 , and radiator  188  form a compressor oil cooler assembly capable of reducing the temperature of the filtered oil that returns to the air compressor  68  along line  192 . An oil fill  189  is also provided in-line between the radiator and the thermostat. 
   The thermostat  186  includes a control valve that directs oil to either the radiator  188  or the first particle filter  74 . When oil is selected by the control valve to pass through the radiator  188 , it also passes through the first particle filter  74  after flowing though the radiator  188  and oil fill  189 . After passing through the first particle filter  74 , the oil enters the air compressor  68 . The air, including a small amount of remaining oil mist, exiting from the oil separator  70  flows through a system that includes the distribution manifold  110  of the present invention. A safety valve  124  is provided to limit the pressure in line  194 . Air pressure gauge  193  is provided to monitor line  194 . The minimum pressure switch  128  is also connected to line  194  to prevent restart of the compressor  68  until pressure in the manifold  110  has reached a pre-set low value. 
   After entering the manifold  110 , the air/oil mixture from line  194  flows through the coalescing filter  72 . Oil is routed along line  196  back to the air compressor  68  through a check valve, orifice, and strainer assembly  197 . Air exiting from the coalescing filter  72  is delivered to a minimum pressure valve  120  by line  204 . If the pressure along line  204  is sufficient, air will pass through the minimum pressure valve  120  to the shut-off valve  54  of  FIG. 1 , which provides compressed air for pneumatic operations of the welder combination  10 . Using air received from the coalescing filter  72 , a pressure regulator  206  regulates air pressure along control pressure line  180  in conjunction with a bleed orifice  208 . Pressure inline  180  controls the position of inlet control valve  178 . Air can also pass from the coalescing filter  72  into a blow-down valve  210  and exit the compressor system  172  through bleed down orifice  214 . Pilot pressure inline  212  is low during compressor operation and will rise upon shut down. This pressure rise will open blowdown valve  210  to release the high pressure air from the system  172  to the atmosphere through orifice  214  at a controlled rate. 
   As can therefore be seen, the manifold  110  provides the various connections and passageways for the overall compressor air an oil routing system  174  so that the individual flows of compressed air can be readily accessed and routed to the necessary components. As also can be seen, the present manifold  110  allows the construction and assembly of the present welder combination  10  to be simplified as it provides physical support as well as proper operational connections for a variety of system components. 
   In accordance with one aspect of the present invention, a welder and air compressor combination includes an air compressor that provides a stream of compressed air containing a quantity of oil. The air containing the oil is directed to an oil separator where the air and the oil are separated. The separated air is then routed through a manifold that has a number of different ports and passageways to enable the construction of the combination by simply attaching fluid conduits and components to the manifold where the internal passageways and fluidly isolated fluid communication systems are formed to carry out the necessary connections for such fluid conduits and components. 
   The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.