Abstract:
A cartridge valve comprises an operator section for operating a valve, and a cartridge section with the valve. The operator section includes a first body and two pistons on a common shaft. The cartridge section includes a second body with valve seat, a cartridge insert having a protruding portion with annular ring, and a valve poppet operably engaging the valve seat. Two retainer screws engage the annular ring to hold the first and second bodies longitudinally together but permit rotation. The piston shaft defines a gap to the valve poppet when in a home position so that the shaft and piston initially gain momentum before abutting the valve poppet. The cartridge insert can be removed from the second body to allow replacement of a poppet seal therebetween.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims benefit under 35 USC section 119(e) of U.S. Provisional Application Ser. No. 61/911,743, filed Dec. 4, 2013, entitled REPAIRABLE AIR PILOT CARTRIDGE VALVE, the entire contents of which are incorporated herein in their entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to air pilot cartridge valves, and more particularly relates to an air pilot cartridge valve that can be disassembled and repaired, and also that resists leakage during high back pressure and additionally that is configured to actuate against high back pressure. 
         [0003]    Air pilot operated cartridge valves have been used for many years, and are commercially available, such as through Doering Company. The known Doering air pilot operated cartridge valve includes an actuator (also called an “operator” herein) incorporating a single acting return air cylinder and a cartridge valve section with single-stem poppet. The cartridge valve section is designed to fit a standard hydraulic valve 8-2 size cavity. The cartridge valve section&#39;s body includes a hex to receive a wrench to facilitate installation. Rotating the hex on the valve section threads the valve into the cavity. The air pilot operator is free to not rotate with the hex. 
         [0004]    The above known air pilot operated cartridge valve has at least three major faults. Its single air piston must be large enough to provide the area for the force necessary to move the poppet off the seat. However, this is especially a problem when the poppet return spring has to have enough force to keep the poppet on the seat when high pressure is on the output port  2  instead of input port  1 , or when pressure on output port  2  is higher than pressure on input port  1 . Also, the poppet seal and air pilot operator in the known air pilot cartridge valve are so difficult to replace that the valve is considered to be a “throw away”. Even the manufacturing company will not repair these valves. Still further, construction design and assembly methods are press fits, such they do not allow space for a replaceable poppet seal. 
         [0005]    More specifically, a large 1⅞″ diameter air pilot operator is necessary when the valve must stop high back pressure flow from a (normally output) port  2  to a (normally input) port  1 . However, larger diameter air pilot sections limit installation options, since such valves are often used in very tight locations on a control manifold. 
         [0006]    Also, air pilot operated cartridge valves are often used as hydraulic valves or valves for high viscosity fluids. For example, I have used them in automatic apparatus lubricating grease systems. In fact, many of my dispensing systems are being used for materials that have an apparent viscosity similar to grease, but that are not lubricating grease. Some of these materials such as anti-seize compounds contain abrasives that can damage dynamic resilient seals. When used to dispense anti-seize compounds, the poppet seal in the known valve can wear out in less than 250,000 cycles (which is costly and a problem since it is not replaceable). 
       SUMMARY OF THE INVENTION 
       [0007]    In one aspect of the present invention, a cartridge valve comprises an operator section including at least one piston; a cartridge section including a second body with viscous fluid inlet and outlet ports, and a valve seat; and a valve poppet operably engaging the valve seat for controlling flow to the outlet port. The first and second bodies include male and female mating sections, the male mating section including an annular groove and the female mating section including at least one hole aligned with the annular groove. A replaceable seal in the cartridge section engages the valve poppet and is accessible when the male and female mating sections are disengaged. At least one releasable retainer extends through the at least one hole and engages the annular groove to hold the first and second bodies longitudinally together but it permits independent rotation. 
         [0008]    In another aspect of the present invention, a cartridge valve comprises an operator section including a first body with pilot inlet and pilot outlet, and at least one piston mounted on a shaft in the first body; a cartridge section including a second body with a fluid inlet port and a fluid outlet port and a valve seat, a valve poppet including a valve head operably engaging the seat; and a retainer holding the first and second bodies together. The shaft defines a gap to the valve poppet when in a valve-closed home position, but abuts the valve poppet when in an air-pilot-operated position so that the shaft gains momentum before engaging the valve poppet when initially moving from the valve-closed home position. 
         [0009]    In another aspect of the present invention, a cartridge valve comprises an operator section including a first body with pilot inlet and pilot outlet, and a piston on a shaft; a cartridge section including a second body with fluid inlet port and fluid outlet port and a valve seat, and a valve poppet including a valve head operably engaging the seat; and a releasable retainer engaging an annular feature on one of the first and second bodies body to hold the first and second bodies longitudinally together but that permits the first body to rotate on the second body. 
         [0010]    In another aspect of the present invention, a method of assembling a cartridge valve comprises providing an operator section including a first body with pilot inlet and pilot outlet, and at least one piston mounted on a shaft in the first body; providing a cartridge section including a second body with a fluid inlet port and a fluid outlet port and a valve seat, a valve poppet including a valve head operably engaging the seat; and assembling the cartridge section to the operator section with the shaft defining a gap to the valve poppet when in a valve-closed home position, but so that the shaft abuts the valve poppet when initially moved from the valve-closed home position toward an air-pilot-operated position, so that the shaft and at least one piston gain momentum before engaging the valve poppet. 
         [0011]    In another aspect of the present invention, a method of assembling a cartridge valve comprises providing an operator section including a first body with pilot inlet and pilot outlet, and a piston on a shaft; providing a cartridge section including a second body with fluid inlet port and fluid outlet port and a valve seat, and a valve poppet including a valve head operably engaging the seat; and assembling an operator section to the cartridge section by installing a retainer that engages a hole in one of the first and second bodies and that engages an annular feature on the other of the first and second bodies to hold the first and second bodies longitudinally together but in a way that permits the first body to rotate on the second body. 
         [0012]    An object of the present invention is to provide a cartridge valve that will fit into very tight spaces, such as in a manifold. It does this in part by its small size, due in part to its double piston design which allows it to actuate against significant downstream backpressure. 
         [0013]    An object of the present invention is to provide a cartridge valve having a replaceable valve poppet seal, which can be replaced without extraordinary training, measures, or equipment. 
         [0014]    An object of the present invention is to provide a cartridge valve having an operator section and mating cartridge section, where the operator section can be pneumatic, hydraulic, mechanical, electrical, or a hybrid of same, yet the cartridge section maintains the advantages noted above. 
         [0015]    These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIGS. 1-1A  are partially-exploded perspective views of an air pilot operated cartridge valve ( 50 ) including an air pilot operator section ( 51 ) and a removable cartridge section ( 52 ). 
           [0017]      FIG. 2  is an end view of  FIG. 1 . 
           [0018]      FIGS. 3-3A  are cross sectional views taken along lines III-III IIIA-IIIA in  FIG. 2 . 
           [0019]      FIG. 4  is a cross sectional view similar to  FIG. 3  but with dashed lines showing air pressure flow. 
           [0020]      FIGS. 5-7  are views of the cartridge section ( 52 ),  FIG. 5  showing the cartridge section fully sub-assembled,  FIG. 6  showing the cartridge insert ( 103 ) removed from the cartridge body ( 101 ) to expose a set-screw-receiving groove ( 106 ′) in the valve poppet ( 106 ),  FIG. 7  showing the PolyPak Seal ( 107 ) and PolyPak Backup Seal ( 108 ) removed from the end of the cartridge insert ( 103 ). 
           [0021]      FIGS. 8-10  are perspective, exploded perspective, and longitudinal-cross-sectioned views of a modified air pilot operated cartridge valve ( 50 ) similar to  FIG. 1  but only including a single-piston-operated poppet. 
           [0022]      FIG. 11  is a plan view of a viscous-fluid-distributing manifold incorporating the valve of  FIG. 1  and showing its tight arrangement of components, and  FIG. 12  is a simplified schematic showing pneumatic controls and fluid-flow lines and metering components. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0023]    The present air pilot operated cartridge valve  50  includes an air pilot operator section  51  that is easily removable from the cartridge section  52  by the removal of shoulder screws  131 . Two shoulder screws  131  hold the cartridge section  52  in the air pilot operator section  51 , and permit the cartridge section  52  to rotate independently of the air pilot operator section  51 . The profile of an end of the air section pilot operator section  51  (i.e. caps/blocks  112 ,  114 ,  115 ) may be square, which facilitates machining and assembly, but it is contemplated that they do not need to be square. The dual air piston design of valve  50  allows the operator to be 1½″ square in end view, and provides more operating force than the known 1⅞″ diameter operator due to operating efficiencies. The present air pilot operator section  51  is configured to provide a flow path of actuating air to the top of both pistons. Holes in the air pilot operator section  51  allow the two shoulder screws  131  to retain the cartridge section  52  in the air pilot operator section  51  while allowing the cartridge section  52  to rotate on the air pilot operator section  51 , as discussed below. 
         [0024]      FIGS. 3-3A  show the following components:  101 —cartridge assembly (including a cartridge insert  103  and components forming a sealed cartridge body for the pistons to operate within),  102 —valve seat,  103 —cartridge insert,  104 —backup washer,  105 —O-ring seal,  106 —valve poppet,  107 —PolyPak high pressure seal,  108 —PolyPak backup seal,  109 —O-ring seal,  110 —collar,  111 —O-ring seal,  112 —operator bottom cap,  113 —pneumatic cylinder tube # 2 ,  114 —operator center block,  115 —operator top cap,  116 —pneumatic cylinder tube #1,  117 —spacer tube,  118 - 120  O-ring seals,  121 —piston #1,  122 —piston #2,  123 —O-ring seal,  124 —piston shaft (also called “button head cap screw” herein),  125 —O-ring seal,  126 —piston return spring,  127 —poppet return spring,  128 —socket head cap screw,  129 —backup washer,  130 —set screw,  131 —shoulder screw. 
         [0025]    The space  140  ( FIG. 4 ) between the air piston actuator (button head cap screw  124 ) and the collar  110  on the poppet  106  is intentional to allow the air piston seals  119  on the air piston  121  to break away so the piston  121  will be already moving when it contacts the collar  110  to move the poppet  106 . The gap can be any size desired for optimal operation based on parameters of a given system. The illustrated gap is about in a range of about 0.020-0.060 inches (or more preferably about 0.030-0.050 inches, or most preferably about 0.035-0.040 inches). Pressurized air flow for causing movement of pistons  121 ,  122  (and movement of actuator  124 ) are shown by dashed lines air  141  in  FIG. 4 . When assembled, the two pistons  121 ,  122  become one on shaft  124 ) and move together as a unit. Compressed air for operating the pistons  121 ,  122  moves longitudinally through a hole(s) adjacent to the threads in the top piston  121 , and in an area of the top piston  121  outside the hole necessary for the bolt  124  that holds the pistons  121 ,  122  together. A downwardly-extending boss of the top piston  121  fits into a bored hole in the bottom piston  122 , but a radial hole(s) in the side of top piston&#39;s boss allows air to enter the area above the bottom piston  122 . The force of the dual piston operator is based on the sum of the area of the top piston  121  and the bottom piston  122 . The top piston  121  uses the full area of a 1.25″ diameter circle to generate actuating force. The bottom piston  122  uses the same area, but less the area of the ½″ diameter boss shaft  124 . 
         [0026]    The poppet spring collar  110  ( FIG. 6 ) is assembled to the poppet  106  via a groove  106 ′ ( FIG. 6 ) in the poppet  106  and set screws  130  threaded in the collar  110 . The present cartridge insert  103  uses a Parker PolyPak seal  107  or similar replaceable seal (and backup PolyPak seal  108 ) as shown with a backup washer  107 ′. Removing the collar  110  from poppet  106  (by removing set screws  130 ) allows its removal from the cartridge insert  103 . Removing the threaded cartridge insert  103  from the cartridge body  101  provides access to the replaceable seal  107  (and if used, backup seal  108 ). The replaceable PolyPak seal  107  is “pressure assisted” and must be inserted as shown. The larger diameter part of the seal  107  is the pressure side and it must face the poppet seat  102 . The location of the seal cavity and access to the seal cavity allows the seal  107  to be reliably and accurately inserted without special tools, and to be inserted and reliably positioned for proper function. 
         [0027]    The present innovative valve  50  with dual piston operator (see pistons  121  and  122 ) allows the valves to be installed on 1½″ centers and have enough air actuator force to operate with 3000 psi on the (output) port  2  side of the poppet. This compares with known valves having a larger 1⅞″ diameter operator, which is necessary for them to function with pressure higher than 400 psi on the (output) port  2 . 
         [0028]    The present innovative valve poppet  106  ( FIGS. 5-7 ) can be easily separated from its cartridge section  52  without the need for highly specialized equipment or training Thus, if the valve air pilot operator section  51  fails, it can quickly and easily be replaced, and/or repaired. 
         [0029]    The present innovative valve  50 , complete with its operator section  51 , can also be removed from its manifold easily. Specifically, the cartridge section  52  can rotate while the air pilot operator section  51  remains stationary, thus greatly simplifying removal since connected lines do not have to be removed first. Also, the hex on the cartridge body  101  has a dimension of 1″ across its flats. This allows this valve  50  to be installed into (and used in) very tight spaces . . . which is a very common problem in viscous fluid distribution manifolds. Alternatively, if there is room for the operator section  51  to rotate, it can be rotated with the hex and with cartridge section  52 , such as during installation or removal. 
         [0030]    As shown by  FIGS. 1 ,  5 - 7 , the present innovative valve  50 , after removal of the operator section  51 , the cartridge section  52  of this innovative valve is easily disassembled for access to the valve poppet  106  and poppet seal  107 . Thus, the poppet seal  107  can be easily replaced. Also, if the stem of the valve poppet  106  shows wear where it moves in the ID of the poppet seal  107 , it can also be replaced. 
         [0031]    A modified valve  50 A ( FIGS. 8-10 ) includes similar components to valve  50 , with identical and similar components being identified using the same number but with the addition of the letter “A”. This is done to reduce redundant discussion. A person skilled in the art will understand that the general operation of valve  50 A is not unlike valve  50 . 
         [0032]      FIGS. 8-10  show the following components of valve  50 A: an air pilot operator section  51 A, cartridge section  52 A, shoulder screws  131 A,  101 A—cartridge assembly (including a cartridge insert  103 A and components forming a sealed cartridge body for the piston to operate within as shown),  102 A—valve seat,  103 A—cartridge insert,  104 A—backup washer,  105 A—O-ring seal,  106 A—valve poppet,  107 A—PolyPak seal,  107 A′—backup washer,  108 A—PolyPak backup seal,  109 A—O-ring seal,  110 A—collar,  111 A—O-ring seal,  112 A—operator bottom cap,  115 A—operator top cap,  116 A—pneumatic cylinder tube #1,  117 A—spacer tube,  118 A- 120 A O-ring seals,  121 A—piston #1,  123 A—O-ring seal,  124 A—button head cap screw,  125 A—O-ring seal,  126 A—piston return spring,  127 A—poppet return spring,  128 A—socket head cap screw,  129 A—backup washer,  130 A—set screw,  131 A—shoulder screws. Valve  50 A resists backflow leakage from backpressure against an outlet port, and also is repairable via replacement of its seal  107 A. 
         [0033]      FIG. 11  is a plan view of a viscous-fluid-distributing manifold incorporating the valve of 
         [0034]      FIG. 1 , showing the very cramped and tight spaces between its components, and  FIG. 12  is a simplified schematic of  FIG. 11  showing only key pneumatic controls and fluid-flow lines and metering components. Specifically,  FIG. 12  illustrates a very-accurate-repeatable cycling metering system with viscous-fluid-distribution/accumulation chamber  200  having an outlet port operably connected to valve  50  (or valve  50 A), which is spring-biased to a normally closed position but which can be actuated to a dispensing position by pneumatic control  201 . The chamber  200  is repeated refilled by viscous fluid supply  202  fed through a second valve  50  (or  50 A) (and if desired through a check valve  231 ), which is controlled by pneumatic air pilot control  203 . Fluid is dispensed from accumulation chamber  200  by a piston  205  operated by rod  206  and pneumatic cylinder  207 , fed compressed air from source  208 . A programmable controller  230  controls operation of the metering system, in part by sensors connected to the system and by controlling the various valves and pneumatics controlling the flow of control air. 
         [0035]    It is contemplated that the present cartridge valve can have an operator section and a mating cartridge section, where the operator section can be pneumatic, hydraulic, mechanical, electrical, or a hybrid of same, yet the cartridge section maintains the advantages noted above. Further, it is contemplated that a kit can be made using a common cartridge section and having a desired operator section attached as desired by the end user. Persons skilled in the art will not require a detailed explanation of pneumatic, hydraulic, mechanical, electrical, or hybrid systems to understand such a valve, nor the advantages of a such a valve system. 
         [0036]    It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.