Abstract:
A pump includes a check valve cartridge removably mounted to the pump. The cartridge includes an inlet check valve and a discharge check valve. A connector mounts intermediate the inlet check valve and the discharge check valve. The inlet and discharge check valves each have a valve ball movable between an open position and a closed position, a valve seat engaging the valve member in the closed position, an inlet and an outlet. The check valve cartridge is threadably mounted to the pump or a manifold and is a self-contained assembly

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is directed to a self contained cartridge-type valve assembly and in particular to a removable check valve cartridge for reciprocating positive displacement pumps. 
         [0003]    2. Description of the Prior Art 
         [0004]    Reciprocating positive displacement pumps utilizing a plunger or diaphragm to pump fluid generally have two check valves; an inlet check valve and a discharge check valve. Such valves may need to be serviced or replaced periodically to provide new seals and to perform other maintenance for normal wear and tear or should other problems arise. If multiple plungers or diaphragms are utilized, each pumping diaphragm typically has an associated inlet check valve and an associated discharge check valve. Multiple sets of valves may be arranged in a manifold. As check valves include many parts and in particular, many small parts, disassembly and replacement can be labor intensive and time consuming and is especially difficult for performing maintenance in the field. 
         [0005]    For some pumps, each of the check valves can be removed as a unit or a cartridge. Such arrangement has an inlet line connected to an inlet check valve that is screwed into the pump manifold. In a similar fashion, the discharge valve is connected to a discharge line. To service the pump, the inlet line and discharge lines are disconnected from the valve and each valve may be separately removed. However, it can be appreciated that even removal of individual valves and servicing can be time consuming and present problems for maintenance of pumps in the field. 
         [0006]    It can be seen that a new and improved pump with a single easily removable cartridge containing both the inlet check valve and the discharge valve is needed to reduce complexity and time required for service and maintenance. Moreover, such a pump should not need to be directly connected to the inlet line or discharge line so that it can be removed and replaced without disconnecting lines. Moreover, such cartridges should be easily removed and mounted to the pump&#39;s manifold and should allow for use with multiple cylinder pumps and should provide for multiple cartridges being directly mountable to a manifold for multiple cylinder pumps to avoid having complex external plumbing connecting to the cartridges. The present invention addresses these as well as other problems associated with pumps and check valves. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention is directed to a valve cartridge for a pump. Fluid pumps such as diaphragm pumps include an inlet check valve and a discharge check valve. 
         [0008]    A check valve cartridge is completely self-contained unit and includes a housing that defines both the inlet check valve and the discharge check valve and is removable as an assembly to replace, interchange or service the inlet check valve and/or the discharge check valve. If multiple valve pairs are utilized, a manifold forming an inlet header and an outlet header is utilized to fluidly connect the valve assemblies and the associated pistons or diaphragms. A passage or header extends from the pumping chamber to the associated check valve cartridge intermediate the inlet check valve and the discharge check valve. 
         [0009]    The check valve cartridge includes a lower housing, a center housing and an upper housing. The center housing connects to the lower housing with a first removable pin while the upper housing connects to the center housing with a second removable pin. The lower housing includes an inlet passage to the inlet header and forms a check valve seat with an inlet valve ball resting against the seat when the inlet valve is closed and being spaced apart from the inlet check valve seat when the inlet valve is open. The first connecting pin also serves as a travel limiter for the inlet check valve ball. 
         [0010]    The center housing includes a passage connecting the manifold passage to the pumping chamber. The center housing includes a seat for the discharge check valve and the discharge valve ball. The second pin connecting the center housing to the upper housing acts as a travel limiter for the discharge valve ball. The center housing also includes an orifice aligning with the header forming the outlet passage through the manifold. 
         [0011]    In one embodiment, the upper housing of the cartridge includes a hex shaped upper head portion adjacent a threaded exterior that mates with complementary threads of the recess in the manifold receiving the cartridge. 
         [0012]    The valve cartridge allows for easily removing and replacing any of the three housings for service or replacing or interchanging the entire assembly for easy disassembly and/or for maintenance and replacement of gaskets and other wear parts. The cartridges are easily accessed for removal from the top of the manifolds and avoid complicated removal of additional pumps elements, as may be required with prior pump check valves. 
         [0013]    These features of novelty and various other advantages that characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings that form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    Referring now to the drawings, wherein like references letters and numerals indicate corresponding structure throughout the several views: 
           [0015]      FIG. 1  is a side sectional view of a portion of a prior art pump and inlet and check valves; 
           [0016]      FIG. 2  is a perspective view of a pump according to the principles of the present invention; 
           [0017]      FIG. 3  is a side sectional view of a pump shown in  FIG. 2  with a diaphragm in a first position; 
           [0018]      FIG. 4  is a side sectional view of the pump according shown in  FIG. 2  with the diaphragm in a second position; 
           [0019]      FIG. 5  is a sectional view of the manifold for the pump shown in  FIG. 2 ; 
           [0020]      FIG. 6  is a perspective view of a check valve cartridge for the pump shown in  FIG. 2 ; 
           [0021]      FIG. 7  is a first side elevational view of the check valve cartridge shown in  FIG. 6 ; 
           [0022]      FIG. 8  is a second side elevational view of the check valve shown in  FIG. 6 ; 
           [0023]      FIG. 9  is a sectional view of the check valve cartridge taken along line  9 - 9  of  FIG. 7  and with the check valves in a first position; 
           [0024]      FIG. 10  is a sectional view of the check valve cartridge taken along line  9 - 9  of  FIG. 7 , but with the check valves in a second position; and 
           [0025]      FIG. 11  is an exploded perspective view of the check valve cartridge shown in  FIG. 6 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0026]    Referring now to the drawings and in particular to  FIG. 1 , there is shown a fluid pump such as a hydraulically driven diaphragm pump, generally designated ( 20 ). The diaphragm pump ( 20 ) is driven by a crankshaft ( 36 ) mounted in a crankcase ( 22 ). The manifold ( 26 ) includes an inlet passage ( 76 ) and a discharge passage ( 74 ). The manifold ( 26 ) also includes one or more inlet check valves ( 72 ) and one or more discharge check valves ( 70 ). 
         [0027]    In the embodiment shown, the pump ( 20 ) is a diaphragm pump and includes a diaphragm ( 46 ) mounted on a valve stem ( 44 ). The diaphragm pump ( 20 ) may be a metering pump with very low flows that requires reliable precision inlet and discharge valves to achieve precise flow rates. However, it can be appreciated that the present invention is usable with many different types of pumps that use check valves. The diaphragm ( 46 ) is hydraulically driven by a plunger ( 42 ) connected to a slider ( 40 ) on connecting rod ( 38 ) to the crankshaft ( 36 ). The diaphragm system includes an overfill check valve ( 48 ) and an underfill check valve ( 50 ). 
         [0028]    The diaphragm ( 46 ) receives fluid in a pumping chamber ( 34 ) and the fluid is pumped while the diaphragm deflects back and forth between an extended position and a fully retracted position. In the prior art system such as shown in  FIG. 1 , the manifold ( 26 ) includes separate inlet check valves ( 72 ) and discharge check valves ( 70 ). 
         [0029]    According to the present invention, a pump ( 20 ) includes one or more check valve cartridges, generally designated ( 100 ) mounting in the manifold ( 26 ) as shown in  FIGS. 2-5 . As shown most clearly in  FIG. 5 , multiple check valve cartridges ( 100 ) connect along an inlet passage ( 54 ) as well as an outlet passage ( 56 ). Pumping chamber passages ( 52 ) lead from each valve cartridge to an associated pumping chamber ( 32 ) for the diaphragm ( 46 ) associated with each of the cartridges ( 100 ). 
         [0030]    Referring now to  FIGS. 6-11 , the check valve cartridge ( 100 ) includes a lower housing ( 110 ), a center housing ( 120 ) and an upper housing ( 130 ). The lower housing ( 110 ) connects to the center housing ( 120 ) by a removable first pin ( 118 ). The first pin ( 118 ) is removable when not mounted and held in place once inserted into the manifold ( 140 ). 
         [0031]    Similarly, the center housing ( 120 ) attaches to the upper housing ( 130 ) by a removable second pin ( 132 ). Like the first pin ( 118 ), the removable second pin ( 132 ) is held in place by the walls of the manifold ( 140 ) when the cartridge ( 100 ) is inserted. The check valve cartridge ( 100 ) is therefore divided into an inlet check valve module and a discharge check valve module. The lower housing ( 110 ) includes an inlet passage ( 112 ) that connects to the inlet passage ( 54 ) of the manifold ( 26 ), which forms a header through the manifold ( 26 ). The lower housing forms an inlet check valve ( 102 ) while the center housing ( 120 ) with the upper housing ( 130 ) forms a discharge check valve ( 104 ). The inlet check valve ( 102 ) includes a valve ball ( 116 ) that seals to an inlet check valve seat ( 114 ) when closed. The inlet check valve ( 102 ) includes O-ring type gaskets or seals ( 150 ) including seals engaging the check valve ball ( 116 ). Moreover, a cylindrical liner ( 138 ) is inserted in each check valve to align the check valve ball ( 116 ) as well as holding the gasket ( 150 ) in proper position. 
         [0032]    Between the valves ( 102 ) and ( 104 ), the center housing ( 120 ) forms a passage ( 122 ) connecting to the pumping chamber passage ( 52 ) formed in the manifold ( 26 ). The center housing ( 120 ) forms a seat ( 128 ) receiving an O-ring type gasket ( 150 ) and the cylindrical insert ( 138 ) holding the gasket in place. The discharge valve ball ( 126 ) engages the gasket ( 150 ) when the discharge check valve ( 104 ) is in the closed position. The pin ( 132 ) connects the center housing ( 120 ) to the upper housing ( 130 ) and acts as a travel limiter for the discharge valve ball ( 126 ). 
         [0033]    The upper housing ( 130 ) includes the hex top ( 106 ) or other shape allowing engagement with a conventional wrench, socket or similar tool that allows for applying the tool to turn the cartridge ( 100 ). The upper housing ( 130 ) also includes a threaded portion ( 134 ) mating with complementary threads ( 142 ) of the manifold ( 26 ) to secure the cartridge ( 100 ). Such a configuration provides for easy and simple removal and interchanging of the entire check valve cartridge ( 100 ) with conventional tools should maintenance or replacement be required. The upper housing ( 130 ) also forms an orifice ( 136 ) that aligns with the outlet passage ( 56 ) formed in the manifold ( 26 ). 
         [0034]    The check valve cartridge ( 100 ) includes both the inlet check valve ( 102 ) and discharge check valve ( 104 ) that are automatically actuated by the pumping action of the diaphragm ( 46 ). During the suction portion of the diaphragm stroke, the valve ball ( 116 ) and the valve ball ( 126 ) are positioned as shown in  FIG. 9 . The suction from the diaphragm ( 46 ) pulls the inlet valve ball ( 116 ) upward to disengage from the seat ( 114 ) and the gasket ( 150 ) so that fluid may pass in through the inlet passage ( 112 ), through the inlet valve ( 102 ) and through the passage ( 122 ) connecting to the pumping chamber passage ( 52 ) leading to the pumping chamber ( 34 ). The travel of the inlet valve ball ( 116 ) is limited by the lower pin ( 118 ) and allows fluid to pass around the valve ball ( 116 ) and through the inlet check valve ( 102 ). 
         [0035]    During this portion of the pumping stroke of the diaphragm ( 46 ), the discharge valve ball ( 126 ) remains in engagement with the discharge check valve seat ( 128 ) and the gasket ( 150 ). This configuration prevents pumped fluid from being drawn back in by the diaphragm ( 46 ). 
         [0036]    Referring now to  FIG. 10 , during the discharge portion of the diaphragm stroke, the inlet check valve ( 102 ) is closed and the discharge check valve ( 104 ) is open. The diaphragm ( 46 ) forces fluid through the pumping chamber ( 34 ) and passages ( 52 ) and ( 122 ) to engage the discharge valve ball ( 126 ) and lift the valve ball ( 126 ) from engagement with the seat ( 128 ) and its respective gasket ( 150 ). Travel of the discharge valve ball ( 126 ) is limited by the pin ( 132 ), but allows fluid to flow around the valve ball ( 126 ). The pump fluid passes through the transverse orifice ( 136 ) aligned with the outlet passage ( 56 ) where it is forced from the manifold ( 26 ). 
         [0037]    During the pumping portion of the stroke of the diaphragm ( 46 ), the inlet check valve ( 102 ) is closed with the inlet valve ball ( 116 ) engaging the inlet valve seat ( 114 ) and its respective gasket ( 150 ). 
         [0038]    It can be seen that the check valve cartridge ( 100 ) provides a simple and reliable operation with only the valve balls ( 116 ,  126 ) moving and having geometry that automatically limits the travel of each of the valve balls ( 116 ) and ( 126 ) in response to pressure changes from the suction or discharge stroke of the pump ( 20 ). Moreover, the entire cartridge ( 100 ) can be removed and replaced or removed and serviced or maintained by simply unscrewing the cartridge ( 100 ) with a conventional wrench or socket. Moreover, the cartridge ( 100 ) is a completely self-contained assembly and configured and accessed so that no additional elements need to be removed in order to service and access the inlet check valve ( 102 ) and/or the discharge check valve ( 104 ). 
         [0039]    It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.