Patent Publication Number: US-6712292-B1

Title: Adjustable adapter for gravity-feed paint sprayer

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is directed to an adapter for a fluid applicator, more particularly to an adjustable adapter for use with a gravity-feed paint sprayer. 
     2. Description of the Related Art 
     Fluids are commonly applied to surfaces with sprayers. For smaller applications, such as automobile painting and repainting in body shops, the fluid is generally placed in a cup attached to the sprayer. In one type of sprayer, the cup is suspended below a front end of the sprayer and the fluid is fed to a nozzle by suction induced by atomization air flow through the sprayer, usually referred to as a suction-feed sprayer. For viscous fluids and for sprayers operating at low air pressures, the cup may be pressurized to increase the fluid application rate. In a second type of sprayer, a cup is mounted above the sprayer body to feed the fluid via gravity to the sprayer so that less air pressure is needed to aspirate the paint, usually referred to as a gravity-feed sprayer. 
     It can be difficult for an operator to use a sprayer to spray paint upwards, particularly if a gravity-feed sprayer is being used, because the level of paint is subject to being below the level of the connection between the paint cup and the sprayer so that paint cannot flow into the sprayer via gravity, a condition known as starvation. 
     Attempts have been made to use an adapter that can be adjusted to different positions so that the paint cup can be moved into an upright position when the sprayer is tilted at various angles. Examples include U.S. Pat. No. 6,536,684 to Wei and U.S. Pat. No. 6,053,429 to Chang, both of which require an assembly of several complicated parts. 
     U.S. Pat. No. 5,803,360 to Spitznagel, particularly FIGS. 6 and 7, teaches a two piece adapter, wherein one piece is rotatable with respect to the other so that the orientation of the paint cup can be changed. However, it does not appear to teach a proper seal around the pivot screw, making it difficult to ensure that paint will not leak. 
     What is needed is an adjustable adapter for a fluid applicator that is uncomplicated and that effectively prevents fluid from leaking from the adapter. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with the present invention, a novel adjustable adapter for connecting a container having an outlet and an applicator having an inlet is provided, wherein the novel adapter comprises a first arm having an axis, a surface normal to the axis with a fluid opening, an end for connection to the inlet of the applicator, and a passageway for fluid communication between the opening and the applicator, a second arm coaxial with the first arm having a surface normal to the axis with a fluid opening, wherein the second arm surface faces the first arm surface, an end for connection to the outlet of the container, and a passageway for fluid communication between the second arm surface opening and the container, a coaxial fastener for pivotally coupling the arms, wherein at least one of the surfaces is provided with a groove in fluid communication with the surface openings, the groove being sealed to prevent fluid from leaking from between said surface, and wherein, when in a rotation-resisting mode, the fastener forces the surfaces of the arms toward one another sufficiently to increase friction and resist rotation therebetween and, when in a rotation-permitting mode, the fastener releases the surfaces sufficiently to decrease friction and permit rotation therebetween. 
    
    
     These and other features and advantages are evident from the following description of the present invention, with reference to the accompanying drawings. 
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is a partial side sectional view of the adjustable adapter of the present invention in a conventional mode engaged with a container and a paint sprayer. 
     FIG. 2 is a partial side sectional view of the adjustable adapter in an upside down mode engaged with the container and the paint sprayer. 
     FIG. 3 is side sectional view of the adjustable adapter of the present invention. 
     FIG. 4 is a sectional view of the adjustable adapter of the present invention taken along the section line  4 — 4  in FIG.  3 . 
     FIG. 5 is a sectional view of the adjustable adapter in the conventional mode showing a paint flow path, taken along the section line  5 — 5  in FIG.  3 . 
     FIG. 6 is a sectional view of the adjustable adapter in the upside down mode showing the paint flow path. 
     FIG. 7 is an exploded perspective view of the adjustable adapter. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1 and 3, an adjustable adapter  10  is shown for connecting a container  12  having an outlet  14  to a fluid applicator  2  having an inlet  13 . The adjustable adapter  10  includes an applicator arm  20  having an axis  16 , a surface  26  substantially normal to axis  16  with a fluid opening  28  in the surface  26 , an end  30  for connection to fluid applicator inlet  13  and a passageway  32  for fluid communication between opening  28  and inlet  13  of fluid applicator  2 , a container arm  22  coaxial with axis  16  of applicator arm  20  having a surface  36  substantially normal to axis  16  with an opening  38  in container arm surface  36 , wherein container arm surface  36  faces applicator arm surface  26 , an end  40  for connection to container outlet  14 , and a passageway  42  for fluid communication between container arm opening  38  and outlet  14  of container  12 , a fastener  44  for pivotally coupling applicator arm  20  and container arm  22 . 
     At least one of the surfaces  26 ,  36  is provided with a groove  50  in fluid communication with surface openings  28 ,  38 , wherein groove  50  is sealed, such as with seals  46 ,  48 , to prevent fluid from leaking from between surfaces  26 ,  36 . Fastener  44  forces surfaces  26 ,  36  toward one another sufficiently to increase friction, resisting rotation between arms  20 ,  22  when fastener  44  is in a rotation-resisting mode, and fastener  44  releases surfaces  26 ,  36  sufficiently to decrease friction and permit rotation between applicator the arms  20 ,  22  when fastener  44  is in a rotation-permitting mode. 
     In a preferred embodiment, adjustable adapter  10  is used for with a liquid applicator, such as a paint sprayer  2 ; therefore the present invention will be described for a paint sprayer, such as a gravity-feed paint sprayer  2  for use in applying paint  1  to coat substrate surfaces. In one embodiment, paint sprayer  2  is used in the automotive refinishing market, such as automobile body shops, for repainting automobiles. 
     Although adapter  10  is described herein for a paint sprayer  2 , it alternatively can be used for supplying other flowable fluids, such as beverages, foods, or condiments (such as ketchup), gasoline, petrochemicals and hydrocarbons, water, water-based solutions, solvent-based solutions, emulsions, and adhesives. Container  12  and adapter  10  must be compatible with the fluid being supplied, and the fluid should flow out of the container in a similar manner as paint from paint container  12 . 
     A paint sprayer  2  is shown in FIGS. 1 and 2 and includes a body  3 , a nozzle assembly  4  secured to a front end  5  of body  3 , and a handle  6  depending from a rear end  7  of body  3 . A trigger  8  is pivotally secured to body  3  for the manual actuation of sprayer  2 . A top mounted, gravity-feed paint container  12  is mounted to body  3  via adapter  10  near front end  5  for feeding paint to nozzle assembly  4 . An air connector  9  is connected to an air hose (not shown) for the delivery of pressurized air to nozzle assembly  4 , wherein the delivery of pressurized air is controlled by trigger  8 . 
     Compressed air from air connector  9  is delivered through an internal passage (not shown) to nozzle assembly  4 . The compressed air acts to atomize paint and deliver it through nozzle assembly  4  to spray paint  1  about a spray axis  11 . Paint  1  is delivered to nozzle assembly  4  via gravity from paint container  12 . The level of paint  1  in paint container  12  must be higher than the sprayer inlet connection channel  13 , or else paint  1  will not feed via gravity to the nozzle assembly  4 , a condition known as starvation. 
     In one embodiment, shown in FIGS. 1 and 2, inlet connection channel  13  is aligned along an applicator arm flow axis  23 , wherein applicator arm flow axis  23  forms an angle à with respect to spray axis  11 . Angle à allows spray axis  11  to be oriented in a level direction and a downward direction, while still supplying paint to inlet connection channel  13 . Preferably angle à is between about 45° and about 60° so that sprayer axis can be oriented horizontally or downward while still providing paint  1  via gravity to sprayer  2 . In the embodiment shown in FIG. 1, angle à is about 55°. 
     Container 
     Continuing with FIG. 1, container  12  is preferably generally cylindrical in shape and has an outlet end  14  with threading  56  for engaging with threading  60  of a lid  58 . Container  12  can have an interior volume of between about 8 fluid ounces and about 2.5 gallons, preferably between about 16 fluid ounces and about 2 liters, still more preferably about 1 liter. A one liter generally cylindrical container  12  can have a length of about 4 inches and a diameter of about 6 inches. However, container  12  can have different proportions or geometries. Preferably, the size and shape of container  12  is conducive to the automobile refinishing industry so that sprayer  2  and paint container  12  are not unwieldy or overly heavy for an operator to handle. 
     Container  12  can be an unlined paint cup, as shown in FIG. 1, or container  12  can be lined (not shown), such as is disclosed in the commonly assigned, co-pending patent application Ser. No. 10/458,478 filed contemporaneously herewith, the disclosure of which is incorporated herein by reference. 
     Container  12  can engage with an adapter lid  58  to engage container  12  with adapter  10 , as shown in FIG. 1, or container  12  can engage directly with the adapter (not shown), such as by threaded engagement between an adapter end with an enlarged diameter to accommodate the diameter of container  12 . 
     Adjustable Adapter 
     Adjustable adapter  10  of the present invention allows applicator arm  20  and container arm  22  to be rotated into different orientations with respect to one another, as shown in FIGS. 1 and 2, to ensure that container  12  is in an upright operative position so paint  1  will flow via gravity into inlet channel  13  of sprayer  2 . Adapter  10  can be rotated between an aligned or conventional spraying mode, as shown in FIG. 1, where fluid is sprayed generally parallel to the ground or at a downward trajectory, and an angled or upside-down spraying mode, shown in FIG. 2, wherein fluid is sprayed generally upward. Because adapter  10  can be adjusted to different spraying modes, it ensures that container  12  will be upright so that fluid will continue to flow into fluid applicator  2  due to gravity. 
     Turning to FIG. 1, when adapter  10  is in the conventional mode, applicator arm  20  and container arm  22  are preferably not angled with respect to one another so that applicator arm flow axis  23  is generally aligned with container arm flow axis  33  so that container outlet  14  is vertically above inlet connection channel  13 , so that paint  1  will flow via gravity through adapter  10  and into sprayer  2 . 
     Turning to FIG. 2, container arm  22  can be rotated with respect to applicator arm  20  into the upside down mode when fastener  44  is in the rotation-permitting mode, described below. When in the upside down mode, container arm flow axis  33  forms an angle à with respect to applicator arm flow axis  23 . Preferably, angle à is small enough to ensure that container outlet  14  is above inlet channel  13 , but not so small that adapter lid  58  comes into contact with sprayer  2  or interferes with paint spraying out of sprayer  2 . In one embodiment, angle à is between about 60° and about 90°, preferably about 75°. 
     In the upside down mode, container arm  22  is angled from the conventional mode so that container  12  is generally upright, as shown in FIG.  2 . Container arm flow axis  33  forms an angle è with respect to sprayer axis  11  which is preferably as small as possible without causing interference between sprayer  2  and adapter lid  58  or container  12 . Angle è should be between about 0°, wherein spray axis  11  and container arm flow axis  33  are generally parallel, and about 45°, preferably about 20°. 
     The lengths of applicator arm  20  and container arm  22  should be chosen so that container  12  will be in a desired location. The length L 1  of applicator arm  20  between the end  15  of sprayer inlet  13  and fastener  44  should be long enough so that container arm  22  is clear from sprayer inlet end  15 . The length L 2  of container arm  22  between fastener  44  and container outlet  14  should be long enough to clear adapter lid  58  and container  12  from inlet end  15  so that container arm  22  can be rotated into the upside down mode without interference between sprayer  2  and container arm  22 , adapter lid  58  or container  12 . However, lengths L 1  and L 2  should not be so long as to be unwieldy for an operator. Further, length L 2  of container arm  22  should be short enough that adapter lid  58  or container  12  will not interfere with paint  1  being sprayed from sprayer  2 . 
     Applicator Arm 
     Turning to FIG. 3, in one embodiment, applicator arm  20  includes an axis  16 , an axial bore  24  for receiving fastener  44 , an end  30  for connection to paint sprayer  2 , a surface  26  with an opening  28  in applicator arm surface  26 , and a passageway  32  for fluid communication between inlet  13  of sprayer  2  and applicator arm opening  28 . 
     Applicator arm end  30  includes threads  62  for engaging with threads  64  of sprayer inlet channel  13 , shown in FIG.  1 . Preferably, threads  62  are of a typical size and pitch for paint sprayers so that adapter  10  can be used with any of several sprayers. In a preferred embodiment, threads  62  are male for engaging with female threads  64  of inlet connection channel  13 . In one embodiment, the diameter of threads  62  of applicator arm end  30  is between about ½ inches and about 1 inch, preferably about ¾ inches. 
     In one embodiment, best seen in FIGS. 4 and 7, applicator arm  20  is chamfered at end  30  and includes a rounded end  31  opposite connection end  30 . The chamfers and rounded end  31  prevent the edges of applicator arm  20  from substantially extending past the edge of container arm  22  as arms  20 ,  22  are rotated with respect to each other, as can be seen in FIG. 6, so that the edges will not interfere with an operator&#39;s work. Rounded end  31  can also be chamfered similar to the chamfers at end  30 . 
     Container Arm 
     Continuing with FIG. 3, in one embodiment, container arm  22  is coaxial with axis  16  and includes an axial bore  34  aligned with applicator arm bore  24 , an end  40  for connecting to container  12 , a surface  36  having an opening  38 , and a passageway  42  for fluid communication between container arm opening  38  and container outlet  14 . 
     In one embodiment, container arm  22  includes threads  68  at container arm end  40  for threaded connection to outlet  14  of container  12 . Threads  68  can engage directly with a threaded container (not shown), or threads  68  can engage with threads  70  of an adapter lid  58 , which engages with container  12  via threading  60  on adapter lid  58  and threading  56  on container  12 . In a preferred embodiment, shown in FIG. 3, threaded end  40  of container arm  22  comprises female threads  68  that engage with male threads  70  on adapter lid  58 . Preferably threads  68  are of a typical size and pitch for adapters and containers of paint sprayers, so that adapter  10  can be used with any of several other adapters, adapter lids and containers. The diameter of threads  68  of container arm end  40  can be between about ½ inches and about 1 inch, preferably about ¾ inches. 
     Container arm end  40  can engage with container  12  and applicator arm end  30  can engage with sprayer  2  by other connection means than a threaded connection, such as a bayonet connection, a snap engagement, or a self-locking taper engagement between the inlet connection and the container (not shown). Novel self-locking tapered connections are described in more detail in the commonly assigned, co-pending patent application Ser. No. 10/458,436 filed contemporaneously herewith, the disclosure of which is incorporated herein by reference. 
     Like applicator arm  20 , container arm  22  can also have chamfers at end  40 , best seen in FIG. 3, and a rounded end  41 , shown in FIG. 7, to prevent edges of the container arm  22  from extending substantially past the edges of applicator arm  20 . 
     Applicator arm surfaces  26  and container arm surface  36  are substantially normal to axis  16 , and preferably are in close proximity to one another for sealing of seals  46 ,  48 , described below. In one embodiment, surfaces  26  and  36  are generally planar, are parallel to one another, and may abut against each other to provide direct friction between surfaces  26  and  36 , described below. 
     Annular Groove 
     Continuing with FIGS. 3 and 7, one of surfaces  26 ,  36  includes a groove  50 , preferably generally annular in shape, in fluid communication with both openings  28 ,  38 , wherein annular groove  50  is spaced radially from bores  24 ,  34 . In one embodiment, best seen in FIG. 7, annular groove  50  is in surface  26  of applicator arm  20 . Alternatively, annular groove  50  can be formed in container arm surface  36 , or each surface  26 ,  36  can include a matching annular groove, wherein the matching annular grooves are aligned with each other. 
     Annular groove  50  provides a flow path  66 , best seen in FIGS. 3,  5 , and  6 , between container arm  22  and applicator arm  20 . Flow path  66  flows from outlet  14  of paint container  12 , through container arm passageway  42 , through container arm opening  38 , around annular groove  50 , through applicator arm opening  28 , through applicator arm passageway  32  and into inlet connection channel  13  of paint sprayer  2 , shown in FIG.  1 . Passageways  32 ,  42 , openings  28 ,  38  and annular groove  50  should be sized to permit a predetermined flow rate of paint through adapter  10 . 
     Seals 
     Groove  50  is sealed to prevent leakage of fluid from between surfaces  26 ,  36 . In one embodiment, groove  50  is sealed with an inner seal  46  and an outer seal  48 . Inner seal  46  is positioned between annular groove  50  and bores  24 ,  34  and outer seal  48  is positioned outside of annular groove  30  to prevent leakage of paint from annular groove  50 . Seals  46 ,  48  preferably are generally annular in shape so that they frame annular groove  50 . Leakage of paint from connections is a common problem, and it is important that annular groove  50  be isolated and sealed. 
     Seals  46 ,  48  may be any type capable of forming a reliable, pressure-tight seal between applicator arm  20  and container arm  22 , but it is preferred that seals  46 ,  48  be of a type that allows for sliding movement of arms  20 ,  22  along seals  46 ,  48  when the arms  20 ,  22  are rotated with respect to each other, while still providing for sufficient friction against surfaces  26 ,  36  to resist rotation when fastener  44  is in the rotation resisting mode, described below. Seals  46 ,  48  should also be chemically resistant to the fluid flowing through adapter  10 . For example, if paint is being supplied to sprayer  2 , seals  26 ,  36  should be chemically resistant to any solvents or other chemicals in the paint. An example of an acceptable seal  46 ,  48  is an elastomeric annular O-ring, or set of O-rings engaged between container arm  22  and applicator arm  20 . O-rings are preferred because of their reliability, and because they are easy to replace and maintain. 
     In the embodiment shown in FIGS. 3 and 7, annular seals  46 ,  48  are compressed between applicator arm  20  and container arm  22  by tightening fastener  44 , described below, to form a seal between surfaces  26  and  36 , preventing paint leakage from adapter  10 . Preferably, seals  46 ,  48  are compressed between about 30% and about 50% of their uncompressed thickness between applicator arm  20  and container arm  22  to ensure a complete seal is formed around annular groove  50 . However, it has been found that as little as about 10% compression of seals  46 ,  48  still provides an adequate seal for most applications. As fastener  44  is tightened more and more, seals  46 ,  48  are compressed more and more between applicator arm  20  and container arm  22  until applicator arm surface  26  may abut against container arm surface  36 , providing a tight seal around the circumference of each seal  30 ,  32 . 
     Seats 
     In one embodiment, best seen in FIG. 7, an inner annular seat  52  is located at applicator arm surface  26  to position and retain inner annular seal  46  in the desired radial position between annular groove  50  and bores  24 ,  34 . Applicator arm surface  26  also includes outer annular seat  54  to position and retain outer annular seal  48  in the desired radial position outside of annular groove  50 . 
     In a preferred embodiment, wherein seals  46 ,  48  are O-ring type seals, annular seats  52 ,  54  are generally annular grooves, best seen in FIG.  7 . The grooves of annular seats  52 ,  54  are preferably substantially less deep than annular groove  50  so that annular seats  52 ,  54  merely retain seals  46 ,  48  but do not conceal them. Preferably, the depths of annular seats or grooves  52 ,  54  are between about ¼ and about ¾ of the thickness of uncompressed seals  46 ,  48 , preferably about ½, so that a portion of seals  46 ,  48  will rise above applicator arm surface  26  and contact container arm surface  36  for sealing between annular seats  52 ,  54  and container arm surface  36 . 
     Inner annular seat  52  and outer annular seat  54  can be provided at either applicator arm surface  26  or container arm surface  36 , or seats  52 ,  54  can each be provided at a different surface. Further, seats  52 ,  54  can be at the same surface as annular groove  50 , as in FIG. 7, both seats  52 ,  54  can be at the opposite surface as annular groove  50 , or one seat can be at the same surface as annular groove  50 , and the other seat can be on the opposite surface. Alternatively, each surface  26 ,  36  can have their own matching inner seat and matching outer seat, wherein the inner seats are aligned and the outer seats are aligned. The locations of seats  52 ,  54  should provide for a proper seal to be formed around annular groove  50  to prevent leakage of paint from adapter  10 . 
     In a preferred embodiment, best seen in FIG. 7, applicator arm surface  26  includes all three grooves, annular groove  50 , inner annular seat or groove  52 , and outer annular seat or groove  54 . The three grooves  50 ,  52 ,  54  are preferably generally concentric about axis  16  and spaced radially from each other and from applicator arm bore  24 , wherein annular groove  50  is the middle groove and is in fluid communication with applicator arm opening  28  and container arm opening  38 , inner annular seal  46  is placed within the inner groove or annular seat  52 , and outer annular seal  48  is placed within the outer groove or annular seat  54 . 
     Fastener 
     Coaxial fastener  44  pivotally couples applicator arm  20  and container arm  22 . In the embodiment shown in FIG. 3, applicator arm bore  24  and container arm bore  34  receive fastener  44  to pivotally couple applicator arm  20  to container arm  22 . Fastener  44  extends through bores  24 ,  34  so that fastener  44  is coaxial with axis  16 . 
     In the embodiment shown in FIGS. 3 and 7, fastener  44  is a locking bolt having a shank  72 , a head  74  at one end of shank  72  and threads  76  at the other end of shank  72 . In a preferred embodiment, head  74  is a thumbscrew, shown best in FIG. 7, so that fastener  44  can be manually adjusted by an operator. 
     Fastener threads  76  can engage with a nut (not shown) or threads  76  can engage with threading  78  in one of the bores  24 ,  34 . In the embodiment shown in FIG. 3, fastener threads  76  engage with threading  78  of threaded bore  34  in container arm  22  and shank  72  is inserted first through applicator arm bore  24  and then through container arm bore  34  so that head  74  abuts applicator arm  20 , as shown in FIG.  3 . In this embodiment, applicator arm bore  24  has an inner diameter that is larger than the outer diameter of shank  72  and threads  76  so that applicator arm  20  is free to rotate around shank  72  or so that fastener shank  72  is free to rotate within applicator arm bore  24 . 
     Fastener  44  is movable between a rotation-resisting mode and a rotation-permitting mode. When fastener  44  is in the rotation-resisting mode, fastener  44  forces container arm surface  36  and applicator arm surface  26  toward one another sufficiently to increase friction at surfaces  26 ,  36  to resist rotation between container arm surface  36  and applicator arm surface  26 , which in turn prevents rotation of applicator arm  20  with respect to container arm  22 , locking adapter  10  in the desired spraying mode. 
     Friction between surfaces  26 ,  36  can be indirect, such as transmission from container arm surface  36  through seals  46 ,  48  to applicator arm surface  26 , wherein the compression of seals  46 ,  48  acts both to seal around annular groove  50  and to brake surfaces  26 ,  36 . Alternatively, the friction can be direct, such as metal-to-metal friction between applicator arm surface  26  and container arm surface  36 . Preferably, the friction between surfaces  26  and  36  is both indirectly through seals  46 ,  48  and through direct contact between surfaces  26 ,  36 . Most of the friction that resists rotation of surfaces  26 ,  36  with respect to one another is created between surfaces  26 ,  36  and seals  46 ,  48 . 
     When fastener  44  is in the rotation-permitting mode, fastener  44  releases applicator arm surface  26  and container arm surface  36  sufficiently to decrease friction between surfaces  26  and  36  and between seals  46 ,  48  and surfaces  26 ,  36 , permitting rotation between container arm surface  36  and applicator arm surface  26 , allowing applicator arm  20  and container arm  22  to rotate freely about axis  16  in order to adjust adapter  10  between the conventional mode shown in FIGS. 1 and 5 and the upside-down mode shown in FIGS. 2 and 6. 
     When fastener  44  is in the rotation-permitting mode, seals  46 ,  48  are not tightly compressed between applicator arm  20  and container arm  22 , decreasing the friction, particular between arms  20 ,  22  and seals  46 ,  48 . Decreased friction at surfaces  26 ,  36  allow applicator arm  20  to rotate freely about fastener. 
     In a preferred embodiment, fastener  44  is moved between the rotation-resisting mode and the rotation-permitting mode by rotating fastener  44  so that threads  76  engage bore threading  78 , driving head  74  toward container arm  22  and causing head  74  to move applicator arm  20  toward container arm  22  to compress seals  46 ,  48  between arms  20 ,  22 , increasing the friction at surfaces  26 ,  36 . Preferably, fastener threads  76  and bore threading  78  are configured so that an operator turns thumbscrew head  74  in a clockwise direction to engage fastener threads  76  with bore threading  78  to move fastener  44  into the rotation-resisting mode and so that an operator turns thumbscrew head  74  in a counterclockwise direction to move fastener  44  out of the rotation-resisting mode and into the rotation-permitting mode. Clockwise rotation for engagement and counterclockwise rotation for disengagement is preferred because these directions are conventional and will be readily understood by operators of paint sprayer  2 . 
     Filter 
     Turning to FIG. 3, adapter  10  can include a filter  80  in one of the passageways  32 ,  42  to filter impurities, such as dust or other particulates, from flowing into sprayer  2  so that the impurities will not be applied to the surface being painted. Filter  80  can be located in either applicator arm passageway  32 , as shown in FIG. 1, or in container arm passageway  42  (not shown). It is preferred that filter  80  be in applicator arm passageway  32  so that filter  80  will be as close to nozzle assembly  4  as possible. Filter  80  is preferably removable, such as with a small handle  82 , so that filter  80  may be cleaned or replaced if it becomes worn or soiled. An example of a filter that can be used is the model KGP-5-K5 filter manufactured by ITW DeVilbiss Automotive Refinishing. 
     The adjustable adapter of the present invention can be used with a gravity-feed fluid applicator to prevent starvation of fluid, even if the applicator is used in various orientations. 
     While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific exemplary embodiment herein. The invention should therefore not be limited by the above described embodiment, but by all embodiments within the scope and spirit of the invention.