Abstract:
A fluid spraying system having a spray gun capable of alternatively selecting a low pressure aerated cleaning or high pressure non-aerated rinsing mode. The system further has an improved interchangeable and disposable fluid cartridge with a combination metering and check valve. The cartridge is sealingly engagable with the gun by use of a bellows fitment. The system utilizes the principle of increased or decreased flow volume to alternatively draw fluid from the cartridge or bypass the cartridge.

Description:
BACKGROUND OF THE INVENTION 
     This application is a continuation-in-part of copending U.S. patent application Ser. No. 265,526, filed Nov. 1, 1988, now U.S. Pat. No. 4,878,619, issued Nov. 7, 1989, entitled A Fluid Spray System Having Replaceable Cartridge. 
    
    
     This invention relates to a pressure fluid spray system, specifically to a hand-held spray gun having an interchangeable and disposable cleaning fluid cartridge wherein the gun has a selector valve for alternatively drawing fluid from the cartridge. 
     There are many spray gun configurations known in the art. The present invention is designed to meet the needs of users who are required to provide for rapid cleaning and rinsing operations without the use of skilled operators. In operations where the cleaning solutions must be accurately formulated because of the high cost and/or high toxicity of the base solution, the present invention provides accurate metering of highly concentrated cleansers or disinfectants. Since the operator is not involved in the metering operation, human errors are largely eliminated. Further, since the metering valve in the improved cartrdige is disposed within the disposable cartridge, accuracy of the amount of fluid delivered for mixing is assured because a new valve is provided more frequently. 
     Another significant advantage of the present invention is that the system provides a spray gun with the capability of alternating between a low pressure (aerated wide spray) cleaning mode and a high pressure (non-aerated narrow spray) rinse mode, without requiring complex operations by the user. A simple operation of the unique selector valving of the present invention allows for a rapid and safe changeover from one mode to another. The user is not required to handle any highly concentrated and/or highly toxic base solution in order to make the switch from cleaning to rinsing. 
     The improved metering valve arrangement of the present invention further allows for most effective manufacturing and assembly of the replacement cartridge. 
     SUMMARY OF THE INVENTION 
     The present invention is a system which combines an interchangeable and disposable cartridge having its own improved metering and check valve combination, as well as a bellows-like sealing fitment for engagement with the spraying valve arrangement. Each time the cartridge is replaced the system uses a new metering valve insuring accuracy of fluid delivered to the gun and a fresh, resilient bellows fitment for sealing engagement with the gun. 
     The spray gun of the present system offers a unique selector valve which enables the user to alternatively draw fluid from the cartridge or bypass the cartridge without requiring the cartridge to be physically removed from engagement with the gun. The system uses the principle of expansion of the volume through which a fluid passes to regulate whether fluid is drawn from the cartridge, as well as providing necessary aeration for the effective mixing and foaming of fluids discharged from the gun nozzle in the cleaning mode. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates a sectional view of the system of the present invention. 
     FIG. 2A illustrates a sectional view of the fitment of the present invention in its relaxed position. 
     FIG. 2B illustrates a sectional view of the fitment of the present invention in its tensioned and sealing position. 
     FIG. 3 illustrates a sectional view of the flow path of the present invention through the selector valve. 
     FIG. 3A illustrates a sectional view of the flow path of the present invention in the cleaning mode. 
     FIG. 3B illustrates a sectional view of the flow path of the present invention in a rinsing mode. 
     FIG. 4 illustrates a sectional view of an alternative fitment housing of the present invention with the metering valve and check valve assembly incorporated therein. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 illustrates a sectional view of the present invention. An interchangeable and disposable, plastic, fluid cartridge 10 is releasably attached to gun 12 by release mechanism 14. Mechanism 14 incorporates a spring loaded release switch 16 which cooperates with latching tabs 18 and 20 to engage latching flange 22 on neck 24 of cartridge 10 to secure cartridge 10 to gun 12. 
     Cartridge 10 has fitted inside of neck 24 a bellow-like soft flexible fitment 26. FIGS. 2A and 2B illustrate fitment 26 in greater detail. As will be discussed further gun 12 has a valve cylinder pin 28 which not only functions as a conduit to draw fluid from cartridge 10, but also functions to pierce fitment 26 forming a force fit seal. FIG. 2A shows fitment 26 in its relaxed condition prior to engagement or piercing by pin 28. FIG. 2B shows the engagement of pin 28 with fitment 26 whereby the z-shaped bellows 30 has been flexed and is in a tensioned position. Pin 28 has been seated against the inner wall 32 of fitment 26 with the tensioned bellows 30 urging sealing of inner wall 32 against pin 28. Thus without the addition of complex sealing mechanisms, a positive, fluid-tight seal is produced between gun 12 (via pin 28) and cartridge 10. 
     Extending downwardly from the bottom portion of fitment 26 is a pickup tube 34. Tube 34 is attached to fitment 26 at an upper end 36 and extends inside of cartridge 10 functioning as a conduit to transport fluid from cartridge 10 to gun 12. On the lower end 38 of tube 34 is attached a combination metering and check valve 40. Orifice 42 in valve 40 is sized to deliver to gun 12 through tube 34 a measured amount of fluid from cartridge 10 when gun 12 is operating in its cleaning or foaming mode as will be described later. Depending upon the particular fluid in cartridge 10, orifice 42 is appropriately sized to ensure the proper concentration of fluid will be mixed in gun 12 prior to discharge to the environment. When gun 12 is operating in its rinse mode, valve 40 operates as a check valve wherein ball 44 in cage section 46 of valve 40 is forced into sealing engagement with the inside seal 48 of orifice 50. 
     It should be noted that cartridge 10 has a concave inner surface 52 on bottom 54 so that there are no cavities or pockets for collection of fluid and tube 34 has a length such that it allows valve 40 to extend to the nadir 56 of concave inner surface 52. Thus cartridge 10 is structured to ensure a complete emptying prior to disposal. Cartridge 10 has base support member 58 which provides a flat external surface on which cartridge 10 may rest without tripping over. 
     Although not shown in the figures, cartridge 10 has a storage cap which is removably secured by any conventional means to neck 24 during storage of cartridge 10. 
     Because cartridge 10 is intended to be disposed of after it is emptied, each time a replacement cartridge is attached to gun 12, the system is supplied with a new metering valve. This ensures not only accurate formulation of the mixed solution, but also eliminates the likelihood of valve plugging so common in the prior art. Further, with each new cartridge, the system is provided with a new fitment 26. Again, this ensures a fresh, resilient seal for engagement with cylinder pin 28. 
     FIG. 1 shows that gun 12 has an outer housing 60 which incorporates a handle section 62, a trigger section 64, a cartridge shroud 66 which includes latching mechanism 14, a nozzle section 68, and a selector switch portion 70. 
     Handle portion 62 further includes an input fluid adaptor 72 for connection to an external fluid source such as a water line. Extending inside and through handle 62 is a handle input conduit 74. Cooperating with trigger section 64 is a tension activated trigger mechanism 76 which selectively engages and disengages a seal plunger (not shown) for allowing input fluid to flow through conduit 74. At the upper end 78 of conduit 74 is attached selector input conduit 80 which directs input fluid toward selector valve 82. Valve 82 is rotatably and sealingly secured within gun 12 in selector switch portion 70 of housing 60. 
     As can be seen in FIG. 3, conduit 80 has on its selector end 81 closest to valve 82 a seal groove 84 for retaining valve seal 86 in sealing engagement with outer sliding surface 88 of valve 82. Further, conduit 80 has vertically extending first detent post 90 and valve neck support shoulder 92. FIG. 3 further illustrates that valve 82 is partially housed for proper alignment within selector end 81 of conduit 80. 
     Cooperating with conduit 80 for partially housing valve 82 is nozzled conduit 94. As with conduit 80, nozzle conduit 94 has a valve neck support shoulder 96 and a vertically extending second detent post 98. Disposed along the intermediate portion of conduit 94 are aeration ports 100 and 102 which allow air to pass into conduit 94 and mix with and aerate fluid passing through conduit 94 on its way to nozzle discharge orifice 104 when valve 82 is positioned for the cleaning mode. Circumferentially around the discharge end 106 of conduit 94 is a nozzle stop flange 108 which abuts against nozzle stop shoulder 110. 
     FIG. 3A illustrates a sectional view taken along line 3A--3A of FIG. 3 and shows flow path from conduit 80, through flow channel 112 of valve 82, through nozzle conduit 94 and eventually out nozzle orifice 104. 
     A first portion of channel 112 is a narrow portion 114. Narrow portion 114 extends from a first side 115 of outer sliding surface 88 to the middle of valve 82 immediately above valve inlet orifice 116. A second portion of channel 112 is a wide portion 118. Wide portion 118 extends from the middle of valve 82 immediately above valve inlet orifice 116 to a second side 117 of outer sliding surface 88. By selectively rotating valve 82, either narrow portion 114 or wide portion 118 may be aligned with conduit 80 to receive fluid from the external fluid source. FIG. 3A illustrates the narrow portion aligned with conduit 80. Rotation of valve 82 is achieved by turning selector valve switch knob 120 which is attached to valve neck 122. Valve 82 is maintained in the selected position by use of a conventional detent system including spring loaded detent plate 124 which engages detent posts 90 and 98. (See FIG. 1, detent not shown in FIG. 3.) 
     Valve 82, as shown in FIG. 3A, is in the cleaning or foaming mode. In this mode fluid (water) flows through conduit 80 from an external source. As the water passes through narrow portion 114 of flow channel 112, the water pressure is at a first pressure. As the water passes over inlet port 116, the water experiences a decrease in pressure because it encounters wide portion 118 of channel 112. This decrease in pressure creates a vacuum in inlet port 116, thereby drawing cleaning fluid from cartridge 10 through valve 40, tube 34, and valve cylinder pin 28. Since valve 40 is a metering valve only a small amount of cleaner is drawn during the operation of the system. 
     Once the fluid from cartridge 10 is mixed with the external fluid from conduit 80 in wide portion 118 of channel 118, the mixed fluid enters nozzle conduit 94. 
     FIG. 3A further shows that nozzle conduit 94 has three sections 130, 132, and 134. Each successive section is wider than the preceding section, section 130 being the narrowest and 134 being the widest. At the leading portion of section 132, on both sides, are disposed aeration ports 100. As the mixed fluid passes from section 130 to section 132, the volume of the flow path is increased and the pressure appropriately decreased. Again, because of the decrease in pressure, air is drawn through port 100 improving the fluid mixing and aerating the mixture. A decrease in flow pressure is also experienced. A second, increased aeration occurs as the fluid then passes into section 134 because aeration ports 102 are disposed on both sides of the leading portion of wider nozzle conduit section 134. As one can see, fluid being discharged from nozzle orifice 104 is now thoroughly mixed, aerated and at a lower pressure. With the proper selection and quantities of fluids from cartridge 10, the present system provides a means for discharging various concentrations of foams in a wide spray of relatively low pressure. 
     After the user has completed a foaming operation, selector switch 120 is rotated as shown in FIG. 3B. In this alternative position, fluid passing out of conduit 80 experiences no appreciable pressure change as it passes into wide portion 118, since portion 118 is essentially the same width as the discharge opening in conduit 80. However, as the fluid passes over inlet port 116, it encounters narrow portion 114, and the fluid pressure is increased. A portion of the fluid will now be forced down through cylinder pin 28, tube 34, and into valve 40. Since valve 40 may function as a check valve, ball 44 is forced into sealing engagement, in cage section 46, with inside seal 48 to close and seal orifice 50. Thus in the alternative mode shown in FIG. 3B, no fluid is drawn from cartridge 10. 
     As the external fluid passes out of narrow portion 114 into nozzle conduit 94, it is exposed to sections 130, 132, and 134, however, since the fluid flow out of narrow portion 114 now has a higher pressure, narrow spray pattern, and there are no aeration ports in section 130, aerating of the fluid prior to discharge from nozzle orifice 104 does not occur. From the foregoing description, it will be appreciated that where the external fluid is water, operation in the alternative mode results in a high pressure rinse cycle with the system. 
     An alternative fitment housing 200 incorporating the metering and check valve assembly is illustrated in FIG. 4. Housing 200 has a flanged rim 202 which may be fitted into the neck of a cartridge similar to the cartridge previously discussed. Rim 202 engages a shoulder within the neck thereby securing housing 200 within the cartridge. 
     A flexible bellows fitment 204, similar to fitment 26 discussed above, is secured within and near the top opening 201 of housing 200 by the engagement of fitment flange 206 into fitment groove 208 on the inside of housing 200. As with fitment 26 (previously discussed) when pin 28 engages with fitment 204, fitment 204 is flexed and is in a tensioned position. Pin 28 is thusly seated against the inner wall 210 of fitment 204 with the tension urging sealing of inner wall 210 against pin 28. 
     Housing 200 further has a metered orifice 212 in the metering valve portion 214 of housing 200. Ball check valve 216 cooperates with valve seat 218 in metering valve portion 214 to control fluid flow through metered orifice 212. Pickup tube 220 is attached to housing 200 at a tubing connector extension 222. Although tube 220 is similar to tube 34 discussed previously, there is no combination metering and check valve 40 on the other end of tube 220 as there is on tube 34. 
     In operation, when gun 12 is operating in the cleaning or foaming mode, fluid is drawn through pickup tube 220 and through orifice 212. Depending upon the particular fluid in cartridge 10, orifice 212 is appropriately sized to ensure the proper concentration of fluid will be mixed in gun 12 prior to discharge to the environment. As fluid is drawn through orifice 212 it enters housing 200 raising check ball 216 from seat 218 and it then passes through orifice 230 in fitment 204 to valve inlet 116 in pin 28. 
     When gun 12 is operating in its rinse mode, metering valve portion 214 operates as a check valve wherein ball 216 is forced into sea ing engagement with valve seat 218 to seal orifice 212 and prevent fluid from passing into cartridge 10 thereby contaminating or diluting the original fluid in cartridge 10. 
     While the invention has been described in connection with a preferred embodiment, it is not intended to limit the invention to the particular form set forth, but, on the contrary, it is intended to cover alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims.