Patent Publication Number: US-10315787-B2

Title: Manual check valve for priming a collapsible fluid liner for a sprayer

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is a continuation of U.S. application Ser. No. 14/656,138 filed Mar. 12, 2015 for “MANUAL CHECK VALVE FOR PRIMING A COLLAPSIBLE FLUID LINER FOR A SPRAYER” by Mariusz J. Luczak. The aforementioned U.S. application Ser. No. 14/656,138 is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     The present invention relates generally to liquid sprayers, and specifically to priming valves for priming the fluid supply of a liquid sprayer. 
     Paint sprayers are well known and commonly used to paint various surfaces. Airless paint sprayers provide the highest-quality finish due to the ability to finely atomize liquid paint. To ensure a high-quality finish from an airless paint sprayer, air cannot be allowed to enter the pumping mechanism of the paint sprayer. Typically, the fluid supply is included in a rigid container and a suction hose is provided within the container. Air then replaces the volume of liquid sprayed throughout the spraying process. The suction hose generally extends to the bottom of the container from the pumping mechanism to allow as much fluid as possible to be sprayed before air begins to enter the suction hose. Alternatively, to ensure that air does not enter the fluid supply, a collapsible liner for holding the liquid to be sprayed can be used, as described in U.S. application Ser. No. 13/660,248 titled Sprayer Fluid Supply with Collapsible Liner, which is hereby incorporated by reference. When a collapsible liner is used, air is purged from the collapsible liner to prime the fluid supply. 
     SUMMARY 
     A fluid supply for a liquid sprayer includes a collapsible liner for holding a liquid, a cup for supporting the collapsible liner, a lid for connecting to the cup to secure the collapsible liner relative to the lid and the cup, and a manual check valve attached to the lid. The manual check valve includes a chamber, a closure, and an orifice extending between the collapsible liner and the chamber. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side perspective view of a spray gun with a fluid supply. 
         FIG. 2  is a side elevation, cross-sectional view along section  2 - 2  in  FIG. 1  of a fluid supply. 
         FIG. 3A  shows a side perspective view of a spray gun with a fluid supply and with a closure in an open position. 
         FIG. 3B  shows a side perspective view of a spray gun with a fluid supply and with a closure in a sealed position. 
         FIG. 4A  depicts a cross-sectional view, along section  4 - 4  in  FIG. 1 , of the connection between a fluid supply and a pumping mechanism of a spray gun before priming. 
         FIG. 4B  is a cross-sectional view along section  4 - 4  showing the connection of  FIG. 4A  after priming the fluid supply and sealing the chamber. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a side perspective view of a portable airless spray gun  10  and fluid supply  12 . Spray gun  10  includes housing  14 , spray tip assembly  16 , pumping mechanism  18 , and drive element  20 . Spray gun  10  also includes priming valve  22  and trigger  24 . Housing  14  includes integrated handle  26 . Spray tip assembly  16  includes guard  28 , spray tip  30 , and connector  32 . Fluid supply  12  includes cup  34 , collapsible liner  36 , lid  38 , and manual check valve  40 . Cup  34  includes cut-out section  42 , and lid  38  includes neck portion  44  and connecting slots  46 . Manual check valve  40  includes chamber  48 , closure  50 , and orifice  52  (shown in  FIG. 2 ). In this embodiment, closure  50  is a hinged cap and includes attachment portion  54 , hinge  56 , and top portion  58 . 
     Collapsible liner  36  is secured within cup  34  and between cup  34  and lid  38 . Cup  34  is removably secured to lid  38 . Collapsible liner  36  is fabricated from a flexible material, such as low density polyethylene, to allow collapsible liner  36  to deform as pumping mechanism  18  draws fluid from collapsible liner  36 . Cup  34  includes cut-out section  42  to allow access to collapsible liner  36  when collapsible liner  36  is secured within cup  34 . Chamber  48  is integral with lid  38 , and chamber  48  projects vertically from lid  38 . Closure  50  is releasably attached to chamber  48 . 
     Pumping mechanism  18  and drive element  20  are disposed within housing  14 . Connector  32  couples spray tip assembly  16  to pumping mechanism  18 . Fluid supply  12  is secured to pumping mechanism  18  by tabs  60  that engage connecting slots  46  in neck portion  44 . Pumping mechanism  18  protrudes through lid  38  and receives fluid from collapsible liner  36 . Guard  28  is attached to connector  32  to prevent objects from directly contacting fluid exiting spray tip  30  at high velocity. 
     Fluid supply  12  is primed by squeezing collapsible liner  36  through cut-out portion  42  with closure  50  removed or left in an open position. When collapsible liner  36  is squeezed, air exits collapsible liner  36  through orifice  52  and chamber  48 . Once air has been purged from collapsible liner  36 , closure  50  is positioned to seal an upper opening of chamber  48 . 
     Spray gun  10  is activated by pulling trigger  24 . Drive element  20  engages pumping mechanism  18 , and pumping mechanism  18  draws liquid from collapsible liner  36 . Collapsible liner  36  continues collapsing as liquid is drawn out of collapsible liner  36 . When spray gun  10  is in use, closure  50  seals an upper opening of chamber  48  to prevent any air from reentering collapsible liner  36  through orifice  52 . The liquid is sprayed through spray tip  30  at high velocity and applied to a desired surface. 
       FIG. 2  is a side elevation, cross-sectional view of fluid supply  12 . Fluid supply  12  includes cup  34 , collapsible liner  36 , lid  38 , and manual check valve  40 . Cup  34  includes cut-out portion  42 , and lid  38  includes neck portion  44  and connecting slots  46 . Manual check valve  40  includes chamber  48 , closure  50 , and orifice  52 . 
     Chamber  48  is defined by floor  48   a  (which contains orifice  52 ), sidewall  48   b , and upper opening  48   c . Closure  50  is used to manually open and close manual check valve  40 . In the closed position, closure  50  covers and seal seals upper opening  48   c  of chamber  48 . 
     In the present embodiment, closure  50  is a hinged cap and includes attachment portion  54 , hinge  56  (shown in  FIG. 1 ), and top portion  58 . Although closure  50  is shown as a hinged cap, other embodiments of closure  50  include a press fit plug or a screw on cap. Attachment portion  54  includes threads  62 A on an inner surface of attachment portion  54 , and chamber  48  includes threads  62 B on an outer surface of chamber  48 . Top portion  58  includes first annular portion  64  extending inwardly from an inner surface of top portion  58  and second annular portion  66  integral with an edge of top portion  58 . Closure  50  further includes annular ridge  68  extending from a top of attachment portion  54 . 
     Collapsible liner  36  is secured within cup  34  when lid  38  is secured to cup  34  at connection  70 . Connection  70  is shown as a press-fit connection in  FIG. 2 . Chamber  48  is integral with lid  38  and extends vertically from lid  38 . Orifice  52  extends through lid  38  to provide a fluid passageway from collapsible liner  36  to chamber  48 . Orifice  52  can have a diameter between about 0.508 millimeters (mm) (0.020 inches) and about 1.778 mm (0.070 inches). More preferably, orifice  52  has a diameter of about 1.016 mm (0.040 inches). Closure  50  is secured to chamber  48  at connection  62 . In the present embodiment, attachment portion  52  is secured to chamber  48  by threads  62 A engaging threads  62 B. While connection  62  is shown as a threaded connection, connection  62  may include mechanical snap connections, press fit connections, or any other suitable connecting mechanism. 
     Collapsible liner  36  is filled with a liquid and collapsible liner  36  is secured within cup  34 . Collapsible liner  36  is secured in place by attaching lid  38  to cup  34 . To prime fluid supply  12  for spraying, air is forced out of collapsible liner  36  by squeezing collapsible liner  36  through cut-out portion  42  in cup  34 . The air is forced out of collapsible liner  36  through orifice  52 , and when the air has been expelled from collapsible liner  36 , the liquid begins to exit through orifice  52  and into chamber  48 . Orifice  52  is sized so air can easily flow out of collapsible liner  36  through orifice  52 , but liquid encounters more resistance when flowing through orifice  52 , which causes a significant increase in the force required to continue expelling fluid from fluid supply  12 . The force increase required to squeeze liquid through orifice  52  signals the user to close closure  50 . 
     In the current embodiment, when closure  50  is sealed, top portion  58  is secured to attachment portion  54 . Sealing closure  50  prevents air from reentering collapsible liner  36  through chamber  48  while spray gun  10  is in use. Capturing expelled liquid in chamber  48  prevents the liquid from leaking onto lid  38  and keeps the priming operation clean, which allows spray gun  10  to be used in any position, including upside down, without worrying about liquid leaking through orifice  52 . 
       FIG. 3A  is a side perspective view of spray gun  10  and fluid supply  12  with closure  50  in an open position.  FIG. 3B  is a side perspective view of spray gun  10  and fluid supply  12  with closure  50  in a sealed position.  FIGS. 3A and 3B  will be discussed together. A portion of spray gun  10  is shown, which includes housing  14 , pumping mechanism  18  disposed within housing  14 , and priming valve  22 . Fluid supply  12  includes cup  34 , collapsible liner  36 , lid  38 , and manual check valve  40 . Cup  34  includes cut-out portions  42 . Lid  38  includes neck portion  44  and connecting slots  46 . Manual check valve  40  includes chamber  38 , closure  50 , and orifice  52 . In the present embodiment, closure  50  includes attachment portion  54 , hinge  56 , and top portion  58 . Top portion  58  includes first annular portion  64  extending inwardly from an inner surface of top portion  58  and second annular portion  66  integral with an edge of top portion  58 . Attachment portion  54  includes annular ridge  68 . 
     Collapsible liner  36  is secured within cup  34  by affixing lid  38  to cup  34 . Chamber  48  is integrally connected to an upper surface of lid  38  and projects vertically from the upper surface of lid  38 . Orifice  52  extends through lid  38  and provides a connection between collapsible liner  36  and chamber  48 . Closure  50  is removably secured to chamber  48  via connection  62 . In the present embodiment, closure  50  is secured by connecting attachment portion  54  to chamber  48 . Hinge  56  connects top portion  58  to attachment portion  54 . Fluid supply  12  is secured to spray gun  10  by tabs  60  that engage connecting slots  46  through neck portion  44 . 
     In the present embodiment, when priming fluid supply  12 , top portion  58  of closure  50  is in the open position ( FIG. 3A ). After air has been purged from collapsible liner  36 , top portion  58  is moved from the open position to the closed position ( FIG. 3B ). When closure  50  is sealed, annular ridge  66  is received between first annular portion  62  and second annular portion  64 , which seals chamber  48 . Sealing chamber  48  prevents air from being introduced into collapsible liner  36  during spraying, which helps ensure that the spray gun  10  provides an even finish. In addition, sealing chamber  48  prevents any liquid disposed in chamber  48  from leaking onto another surface of spray gun  10 . 
       FIG. 4A  depicts a cross-sectional view of the connection between fluid supply  12  and pumping mechanism  18 , and shows fluid line F before priming fluid supply  12 .  FIG. 4B  depicts the cross-sectional view of  FIG. 4A  after priming fluid supply  12 . Fluid supply  12  includes cup  34 , collapsible liner  36 , lid  38 , and manual check valve  40 . Cup includes threads  70 B. Lid  38  includes neck portion  44  having connecting slots  46 , threads  70 A and lip  72 . Manual check valve  40  includes chamber  48 , closure  50 , and orifice  52 . Closure  50  includes attachment portion  54 , hinge  56 , and top portion  58 . Top portion  58  includes first annular portion  64  extending inwardly from an inner surface of top portion  58  and second annular portion  66  integral with an edge of top portion  58 . Closure  50  further includes annular ridge  68  arranged at a top of attachment portion  54 . A portion of pumping mechanism  18  is shown and includes suction tube  74  and extensions  76 . 
     Collapsible liner  36  is secured within cup  34  and between lid  38  and cup  34 . Cup  34  is secured to lid  38  at connection  70 . Connection  70  includes threads  70 A on an inner portion of lid  38  and complementary threads  70 B on an outer portion of cup  34 . Although connection  70  is shown as a threaded connection, connection  70  may include mechanical snap connections, press fit connections, or any other suitable connecting mechanism. When fluid supply  12  is attached to pumping mechanism  18 , lip  72  sealingly engages pumping mechanism  18  such that air or liquid in collapsible liner  36  must exit collapsible liner  36  through orifice  52  and into chamber  48  during priming. Closure  50  is releasably secured to chamber  48  at connection  62 . In the embodiment shown, connection  62  includes threads  62 A on an inner area of attachment portion  54  and threads  62 B on an outer area of chamber  48 . 
     Collapsible liner  36  is filled with the liquid to be sprayed and collapsible liner  36  is secured within cup  36  by affixing lid  38  to cup  36  at connection  70 . Fluid supply  12  is secured to pumping mechanism  18  by tabs  60  engaging connecting slots  46 . To prime fluid supply  12  before use, collapsible liner  36  is squeezed through cut-out portion  42  to force air out of collapsible liner  36  through orifice  52  and chamber  48 . When fluid level F rises to the level that liquid begins to enter chamber  48  through orifice  52 , closure  50  is closed to seal chamber  48  ( FIG. 4B ). Sealing closure  50  keeps fluid supply  12  primed by preventing air from entering collapsible liner  36  as collapsible liner  36  continues collapsing during use. Sealing closure  50  also prevents liquid in chamber  48  from spilling onto another surface of spray gun  10 . Extensions  76  on suction tube  74  prevent collapsible liner  36  from being sucked into suction tube  74  when spray gun  10  is in use. If collapsible liner  36  were to be sucked into suction tube  74 , it may clog suction tube  74 , preventing fluid from entering pumping mechanism  18 . 
     The manual check valve described herein provides several advantages. Manual check valve  40  provides chamber  48  for liquid to be contained in without spilling onto other surfaces, preventing any messy cleanup. In addition, orifice  52  is large enough that it will not become clogged, but if orifice  52  does become clogged it can easily be cleared by passing an object, such as a pipe-cleaner, though orifice  52 . Orifice  52  allows the same fluid supply  12  to be reused by the user, which reduces the user&#39;s costs because a new lid does not have to be used for each spraying job. The small diameter of orifice  52  allows air to easily be expelled from collapsible liner  36 , but the diameter prevents liquid from quickly entering chamber  48  and increases the amount of force that the user must apply to continue pushing liquid out of collapsible liner  36  after the air has been expelled. This increase in force notifies the user to seal closure  50  and prevents the liquid from overflowing chamber  48  before the user can seal closure  50 . 
     Closure  50  prevents air from entering collapsible liner  36  through orifice  52  during use. Additionally, closure  50  is removable from chamber  48 , which allows the user to transfer closure  50  between various fluid supplies  12 , decreasing the user&#39;s costs. A removable closure  50  also allows the user to replace closure  50  if it becomes worn out due to excessive use without having to replace the entire fluid supply  12 . 
     While the invention has been described with reference to an exemplary embodiment(s), 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. 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(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.