Patent Document

CROSS REFERENCE TO RELATED APPLICATION(S)  
       [0001]     Not applicable.  
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not applicable.  
       REFERENCE TO A MICROFICHE APPENDIX  
       [0003]     Not applicable.  
       TECHNICAL FIELD  
       [0004]     The present invention is directed toward check valves, and particularly toward check valve position detectors.  
       BACKGROUND OF THE INVENTION AND TECHNICAL PROBLEMS POSED BY THE PRIOR ART  
       [0005]     Check valves may be used, for example, to prevent back flow through a conduit. When flow in the desired direction occurs through the conduit, the check valve will automatically be opened by the pressure of the flow. Where such flow is provided by a pump, such a check valve will normally always be open during proper operation of the pump.  
         [0006]     In some applications, therefore, check valves having check valve arms or handles are used. Such check valve arms are disposed outside the conduit but are mechanically connected to the associated valve, whereby the position of the valve inside the conduit can be manually controlled when desired by manipulating the handle. Further, the position of the valve can be visually determined based on the position of the check valve arm.  
         [0007]     Of course, visual inspection of valves is not adequate in many situations, as they may not be in conveniently seen locations, and will typically operate round the clock whereby constant operator supervision would be impractical and/or impossible. Therefore, limit switches have heretofore been used to detect pump failure by detecting whether or not a check valve is closed when the pump is supposed to be operating. However, limit switches are expensive, and are difficult to install and adjust.  
         [0008]     Mercury switches have also been used to detect pump failure based on detection of a closed check valve when the pump is supposed to be operating. However, such switches have required clear tube switches in order to be able to see whether the switch is making contact in the proper valve position. This requires that the tubes be exposed so that they can be seen, which also makes them particularly susceptible to breakage. Further, even where the switch appears to an observer to be making contact, it can be difficult to determine visually whether or not such contact is steady. To overcome this, or where the switch has not been adequately visible, cumbersome additional equipment, such as meters or test lights, have been used to ensure proper positioning of the switch relative to the check valve arm.  
         [0009]     The present invention is directed toward overcoming one or more of the problems set forth above.  
       SUMMARY OF THE INVENTION  
       [0010]     In one aspect of the present invention, a position detector for a check valve is provided, where the valve includes a check valve arm pivotable in response to a change in position of the check valve. The detector includes a bracket with a connector adjustably connecting a tilt switch in a selected pivotal position around an axis oriented transverse to the bracket legs. The bracket includes a long leg connected at its lower end to a parallel small leg by a bottom leg, and a support arm extends from the upper end of the long leg with a portion facing the bottom leg, whereby the check valve arm is receivable between the support arm and the bottom leg and between the long leg and the short leg. Set members on one of the short leg and long leg and one of the bottom leg and the support arm are adjustably movable toward the other. The detector also includes a wire connector for both the tilt switch and a circuit status indicator, and a first plug is selectively securable to the wire connector to form a first circuit with the tilt switch and the circuit status indicator when the tilt switch is in a selected position.  
         [0011]     In one form of this aspect of the invention, the first plug includes a power source for the circuit. In a further form, the power source is a battery.  
         [0012]     In another form of this aspect of the invention, a second plug is selectively securable to the wire connector to form a second circuit with the tilt switch and a controller, wherein the controller operates responsive to the condition of the tilt switch.  
         [0013]     In a further form of this aspect of the invention, the circuit status indicator is a light emitting diode, and in a still further form, the light emitting diode is integral with the tilt switch.  
         [0014]     In another aspect of the present invention, a position detector for a check valve is provided, including a bracket with a support arm, adjustable securing members adapted to rigidly secure the bracket to the check valve arm, a tilt switch, a connector, a circuit status indicator, a wire connector for both the tilt switch and the circuit status indicator, and a first plug. The connector adjustably connects the tilt switch to the bracket support arm in a selected one of a plurality of secure positions pivoted around an axis fixed to the bracket support arm, the axis being oriented generally horizontally when the securing members secure the bracket to the check valve arm. The first plug is selectively securable to the wire connector whereby a first circuit with the tilt switch and the circuit status indicator is formed when the tilt switch is in a selected position.  
         [0015]     In one form of this aspect of the invention, a second plug is selectively securable to the wire connector to form a second circuit with the tilt switch and a controller, wherein the controller operates responsive to the condition of the tilt switch. In a still further form, the tilt switch closes the second circuit when the check valve arm is in a position corresponding to the check valve being closed, the controller controls a pump adapted to pump through the valve, and the controller activates a pump operation alarm when operating the pump if the second circuit closes.  
         [0016]     In another form of this aspect of the invention, the bracket has a long leg generally parallel to a small leg, where the long and small legs are interconnected at their lower ends by a bottom leg, and the support arm extends from the upper end of the long leg, is spaced from the small leg and includes a portion facing the bottom leg, where the check valve arm is receivable between the support arm and the bottom leg and between the long leg and the short leg.  
         [0017]     In a still further form of this aspect of the invention, the securing members include a first set member on one of the short leg and long leg and a second set member on one of the bottom leg and the support arm. The first set member is adjustably movable toward the other of the short leg and long leg, and the second set member is adjustably movable toward the other of the bottom leg and support arm.  
         [0018]     In yet another form of this aspect of the invention, the first plug includes a power source for the circuit. In a further form, the power source is a battery.  
         [0019]     In still another form of this aspect of the invention, the circuit status indicator is a light emitting diode, and in a still further form the light emitting diode is integral with the tilt switch.  
         [0020]     In another aspect of the present invention, a method of securing a position detector to a check valve arm pivotable responsive to a change in position of a check valve of a pump is provided, including the steps of (a) securing a support bracket to the check valve arm, the support bracket supporting a tilt switch pivotable about a generally horizontal axis relative to the support bracket, (b) providing a powered circuit through the tilt switch and a position indicator associated with the tilt switch, (c) pivoting the tilt switch while the check valve arm is in a closed position until the position indicator is activated by the powered circuit, (d) securing the tilt switch against pivoting relative to the support bracket, and (e) providing a monitoring circuit through the tilt switch and a controller controlling the pump. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]      FIG. 1  is a side view of an example pump application incorporating the present invention;  
         [0022]      FIG. 2  is a front view of a tilt switch as incorporated in the present invention;  
         [0023]      FIG. 3  is a side view of the tilt switch of  FIG. 2 ;  
         [0024]      FIG. 4  is circuit diagram of a wire connector for a tilt switch usable with the present invention; and  
         [0025]      FIGS. 5   a - 5   c  are circuit diagrams of different plugs usable with the wire connector of  FIG. 4 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0026]     An exemplary application of a pump station  10  with which the present invention may be used is illustrated in  FIG. 1  with an embodiment of the present invention. In the illustrated application, a suitable pump  12  is driven by a suitable motor  14  to propel the applicable fluid (such as water or wastewater) through a check valve  18  and, for example, a plug valve  20 . The check valve  18  includes a check valve arm or handle  24  which is pivotably connected to the check valve  18  whereby the check valve arm  24  will pivot responsive to a change in condition of the valve  18  (e.g., between open and closed conditions).  
         [0027]     As illustrated in  FIG. 1 , the check valve arm  24  is in a substantially horizontal position with the check valve  18  in a closed position. The valve  18  may be manually opened by counterclockwise pivoting of the check valve arm  24 . Moreover, when the pump  12  is operating properly and is pumping fluid through the check valve  18  so as to force it open, the check valve arm  24  will be similarly pivoted automatically due to the force of the pumped fluid.  
         [0028]     Suitable conduit, including additional valves (not shown), may be connected to the plug valve  20  to carry the pumped fluid as desired to locations outside the pumping station  10  such as is well known.  
         [0029]     A suitable tilt switch  30  is secured to the check valve arm  24 , as better illustrated in  FIGS. 2-3 .  
         [0030]     Specifically, a mounting bracket  40  is suitably secured to the check valve arm  24  as best seen in  FIG. 3 . The advantageous illustrated bracket  40  includes a short leg  42  and a long leg  44  connected on their bottom ends by a bottom leg  46 , whereby the three legs  42 ,  44 ,  46  are in a generally “J” configuration. The bottom leg  46  is sufficiently long to space the short and long legs  42 ,  44  apart a sufficient distance so that the check valve arm  24  will fit between them with some room to spare.  
         [0031]     A support arm  50  is connected to the upper end of the long leg  44  and extends therefrom in the same direction as the bottom leg  46  so that a portion  52  of the support arm  50  faces the bottom leg  46 . Further, the support arm  50  is spaced from the short leg  42  by a sufficient distance so that the check valve arm  24  will fit between the two ( 46 ,  50 ) during assembly.  
         [0032]     Both the short leg  42  and the support arm  50  include screw holes receiving set screws  56 ,  58  extending toward the facing legs (long leg  44  for the short leg  42  and bottom leg  46  for the support arm  50 ). As illustrated in  FIG. 3 , the set screws  56 ,  58  may be screwed in (toward the facing legs  44 ,  46 ) so as to bias against the check valve arm  24  and at least frictionally secure the check valve arm  24  between each set screw  56 ,  58  and its facing leg  44 ,  46 .  
         [0033]     The legs  42 ,  44 ,  46  may advantageously have a configuration (their depth in  FIG. 3 , their width in  FIG. 2 ) which matches the engaged check valve arm  24 , in which case the engaged surfaces and frictional engagement may be maximized. Thus, when used to attach to a check valve arm which is, for example, cylindrical, the bottom leg may be a matching semi-cylindrical shape whereby the short, bottom and long legs would form a more classic “J” shape. Moreover, the set screws  56 ,  58  may be advantageously oriented at right angles as shown in  FIG. 3 , whereby the bracket  40  may be rigidly secured to the check valve arm  24  in all directions of possible motion. Suitable hex nuts  60 ,  62  or the like may be provided with each set screw  56 ,  58  to secure the set screws  56 ,  58  in place when they are suitably tightened against the check valve arm  24  to secure the bracket  40  thereon as described. It should be appreciated that this bracket  40  may be quickly, easily and reliable securely mounted on the check valve arm  24  such that the bracket  40  position will strictly follow the position of the check valve arm  24 .  
         [0034]     The support arm  50  also includes a connecting flange  70  which is oriented (when the bracket  40  is mounted to the check valve arm  24 ) in a generally vertical direction and includes a hole  72  which is cylindrical about an axis  74  extending substantially perpendicular to the connecting flange  70 .  
         [0035]     A mounting plate  78  is secured to the connecting flange  70  via a suitable pivot screw  80  and nut  82 . As discussed in greater detail hereafter, the mounting plate  78  may be pivoted in a substantially vertical plane about the pivot screw  80  to a desired upright mounted orientation, after which it may be secured in that orientation by tightening of the pivot screw  80  and nut  82 . Suitable lock washers  84  may also be provided to assist in maintaining the mounting plate  78  in the desired orientation even if bumped from time to time while mounted.  
         [0036]     Rigidly secured to the mounting plate  78  is a switch box  86  which includes the tilt switch  30 , a switch position indicator such as a light emitting diode (LED)  88 , and a suitable wire connector as discussed in greater detail hereafter in connection with  FIGS. 4 and 5   a - c.    
         [0037]     A wire connector  92  is also included with the switch box  86 , which may be suitably connected with a wire plug  94 . As illustrated diagrammatically in  FIG. 3 , the wire plug  94  may be connected by a suitable wire or cable  96  to a suitable pump controller  98  connected to a pump operation alarm  99 , as also described in greater detail hereafter in connection with  FIGS. 4 and 5   a - c.    
         [0038]     Referring now to  FIGS. 4 and 5   a - c,  the wire connector  92  is illustrated diagrammatically as having 4-pins  100 ,  102 ,  104 ,  106 . The LED  88  is connected in a circuit  110  connected to two of the pins  100 ,  102  and the tilt switch  30  is connected in a circuit  112  to the other two pins  104 ,  106 .  
         [0039]     The connector  92  is connectable to a selected wire plug  94  depending on the application. Three different wire plugs  94   a,    94   b,    94   c  are diagrammatically illustrated in  FIGS. 5   a,    5   b,  and  5   c,  respectively.  
         [0040]     The wire plug  94   a  illustrated in  FIG. 5   a  may be used to create a battery circuit. That is, terminals  120  and  126  are connected to a circuit  130  with a battery  132  (e.g., a 3 volt battery), and terminals  122 ,  124  are connected together. Wire plug  94   a  may be connected to the connector  92  whereby pins  100 ,  102 ,  104 ,  106  connect to terminals  120 ,  122 ,  124 ,  126 , respectively, thereby forming a single closed circuit in which the battery  132  provides power through the tilt switch  30  and the LED  88 . It should therefore be appreciated that when the tilt switch  30  is oriented so as to be closed, the LED  88  visible right on the switch box  86  will be illuminated.  
         [0041]     The PLC wire plug  94   b  illustrated in  FIG. 5   b  is similar to that in  FIG. 5   a , except that the terminals  140 ,  142 ,  144 ,  146  when connected to the connector pins  100 ,  102 ,  104 ,  106  may form a closed circuit via wiring to the programmable control logic (PCL) of a controller  98   b.  Thus, with this wire plug  94   b,  a first wire  150  may be connected to the PCL, and a second wire  152  to ground. Since the PCL is typically low voltage, the LED  88  may be advantageously included in the circuit to continuously provide a switch position indication without being damaged.  
         [0042]     The relay logic wire plug  94   c  illustrated in  FIG. 5   c  may be used with a controller  98   c  with a relay logic. In this case, only two terminals  164 ,  166  are used, with one connected to a wire  170  connected to ground and the other connected to a wire  172  connected to the relay logic. Since such a relay logic typically operates at 120 V, the LED  88  is not included in the circuit, as such voltage would damage the LED  88 .  
         [0043]     It should now be understood that the above wire plugs  94   a - c  can be selectively and advantageously used as follows.  
         [0044]     The bracket  40  is first secured to a check valve arm  24  as previously described, whereby the connecting flange  70  is oriented in a generally vertical direction. The mounting plate  78  is loosely connected to the connecting flange  70  via the pivot screw  80  and nut  82  so that it can be pivoted around the axis  72 .  
         [0045]     With the check valve arm  24  in a position corresponding to the check valve  18  being closed, the mounting plate  78  is properly positioned as follows.  
         [0046]     Either the battery plug  94   a  or the PLC plug  94   b  (if a PLC controller  98   a  is being used) is connected to the connector  92 , thereby creating a powered circuit through both the LED  88  and the tilt switch  30  as previously described. The mounting plate  78  is then pivoted in the substantially vertical plane about the pivot screw  80  as previously described to a position in which the tilt switch  30  is closed, as will be indicated by the steady lighting of the LED  88 . In that position, the pivot screw  80  and nut  82  are tightened whereby the mounting plate  78  will be securely held on the connecting flange  70  of the bracket  40 .  
         [0047]     If a PLC plug  94   b  was used, installation at that point will be complete. If a battery plug  94   a  was used, it may then be removed and connected to a suitable plug  94   b,    94   c  connected to the appropriate controller  98   b,    98   c.    
         [0048]     The controller  98   b,    98   c  may then function normally to operate the pump  12 . Whenever the pump  12  is operating normally, the check valve  18  will be open, causing the check valve arm  24  to pivot from the closed position (e.g., the horizontal position indicated in  FIGS. 1-3 ). When the check valve arm  24  is pivoted from the closed position, the mounting plate  78  and tilt switch  30  connected thereto will also be pivoted to a different orientation, causing the tilt switch  30  to open. This will cause the circuit through the wiring to the programmable control logic (PCL) of controller  98   b  or to the relay logic controller  98   c  to open, which the controller  98   b  or  98   c  may be suitably programmed to recognize as an indication the pump  12  is not operating properly. In such a situation, the controller  98   b  or  98   c  may be further programmed to activate the alarm  99  to indicate improper operation of the pump  12 . The alarm  99  may be any suitable indicator such as may draw the attention of a user to the detected pump condition, such as a bell, buzzer, light, generated message for a computer monitor, etc., depending on the pump station  10 . Operation of the controller  98   b  or  98   c  could additionally be changed responsive to such a condition by, for example, shutting down power to the pump  12 , activating backup pumps, etc.  
         [0049]     It should be appreciated that the above described invention may also be advantageously used in other applications. For example, at pumping stations, detectors broadly incorporating the present invention may be used to detect when a cover of a well mounted pump station has been lifted (indicating possible unauthorized entry) or to actuate a blower responsive to detection of the lifting of an entrance lid to a below grade pump station, in addition to detecting pump failures as already described.  
         [0050]     Still other aspects, objects, and advantages of the present invention can be obtained from a study of the specification, the drawings, and the appended claims. It should be understood, however, that the present invention could be used in alternate forms where less than all of the objects and advantages of the present invention and preferred embodiment as described above would be obtained.

Technology Category: 4