Abstract:
A valve position indicator is directly coupled to a valve shaft. The indicator has a gauge that directly indicates rotation of a valve shaft in a subterranean valve.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   The present application is based on and claims the benefit priority under 35 U.S.C. § 119 to U.S. Provisional Application No. 60/719,510, filed on Sep. 22, 2005, the entire contents of which is expressly incorporated by reference herein. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention generally relates to position indicators for buried valves. More specifically, the present invention relates to position indicators that directly relate a position of a valve element, such as a butterfly, plug or the like, of a valve that is buried in the ground. 
   2. Description of the Related Art 
   Various types of valves are designed to be buried in the ground. These valves can be used to stop or otherwise control the flow of materials through subterranean pipelines and the like. 
   One type of valve is considered a quarter-turn valve. There are a number of different versions of the quarter-turn valve, including but not limited to plug valves, ball valves and the like. A quarter-turn valve is so named because the element that controls flow turns one quarter of a revolution between its full open position and its full closed position. 
   Some quarter-turn valves are very large and heavy. Thus, multiple turn actuators are coupled to the valves through suitable linkages or gear trains. The actuators can be manual actuators or mechanized actuators. In some cases, a hand wheel is mounted to an elongated shaft. The elongated shaft rotates a worm gear at its lower end. The worm gear is positioned in a gear box. The worm gear rotates a gear that is coupled to a valve shaft. The valve shaft is fixed to the element of the valve that occludes or opens the flow passage through the valve. Depending upon the worm gear and gear combination, tens or hundreds of turns of the hand wheel can be required to move the valve element through its quarter-turn sweep. 
   In many cases, the relative position of the valve element is determined either by counting the number of times the hand wheel is turned or, even more often, simply by the sensory feedback of the field operator. Both of these alternatives can easily lead to catastrophic valve failure. For instance, if the operator loses count of the rotations, which can sometimes number in the hundreds, the operator may damage the valve. Similarly, if the valve operates harder than normal for some reason, the operator may not realize that the valve has not been fully opened and the operator then may damage the valve during a subsequent closing. 
   To address these concerns, a valve position indicator was previously developed in which an indicator dial was mounted to the elongated shaft that connects the hand wheel to the gear box. Through the use of gearing connected near the actuator (e.g., the hand wheel), the several rotations of the elongated shaft could be translated into movement of an indicator dial from an open indicator position to a closed indicator position. 
   While this indicator was functional, it had a few drawbacks. For instance, if the gearing broke on the indicator, the indicator would fail to provide a reading. More critically, if part of the drive used on the manual actuator (e.g., the elongated shaft, the worm gear, the gear or the valve shaft) failed, the elongated shaft would continue turning and this would cause movement of the indicator dial, thereby providing a false indication of the valve element position when the breakage occurred. 
   Some valve and actuator combinations that were designed for above ground use featured a valve element position indicator that was directly coupled to the valve shaft. These indicators would turn through a quarter turn as the valve shaft and the associated valve element turned through its quarter turn. The indicator could take the form of a short tab that was mounted to sweep over a small region on a housing of the actuator. While these indicators were suitable for above ground use, these indicators could not be read in most subterranean applications. 
   SUMMARY OF THE INVENTION 
   Thus, a need for an improved valve position indicator for use with quarter turn valves is desired. 
   One aspect of the present invention involves a valve position indicator. The valve position indicator comprises a gauge. The gauge is supported by a bracket. A tubular housing has a first end connected to the gauge and a second end connected to a valve assembly. The valve assembly comprises a valve shaft. A drive link is positioned within the tubular housing. A first end of the drive link is connected to an indicator of the gauge and a second end of the drive link is directly coupled to the valve shaft such that rotation of the valve shaft results in direct rotation of the drive link. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features, aspects and advantages of the present invention will now be described with reference to the drawings of a preferred embodiment. The preferred embodiment is intended to illustrate and not to limit the invention. The drawings comprise five figures. Additional images are provided in an appendix attached hereto. 
       FIG. 1  is a perspective view of a valve, actuator and indicator assembly that is arranged and configured in accordance with certain features, aspects and advantages of the present invention. 
       FIG. 2  is a side elevation view of the assembly of  FIG. 1 . 
       FIG. 3  is a partially sectioned side elevation view of the assembly of  FIG. 1 . 
       FIG. 4  is an enlarged view of a portion of  FIG. 3  that is indicated by the circle  4 - 4  in  FIG. 3 . 
       FIG. 5  is an elevation view showing another actuator mechanism. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   With reference now to  FIG. 1 , an assembly  20  is illustrated therein. The illustrated assembly comprises an actuator  22 , a valve  24  and a position indicator  26 . The present invention primarily relates to the position indicator  26  and its coupling to the valve  24  but the actuator  22  will likely be present in most embodiments of the present invention. 
   The illustrated actuator  22  comprises a hand wheel  30  that is joined for rotation with an elongated shaft  32 . The wheel  30  and the shaft  32  can be coupled in any suitable manner. In one configuration, the wheel  30  is attached to the shaft  32  with a threaded fastener. In another configuration, the wheel  30  is welded to the shaft  32 . The connection between the wheel  30  and the shaft  32  can have any suitable configuration and further description of the connection is not needed to understand, make or use the present invention. 
   In some configurations, such as that shown in  FIG. 5 , the wheel  30  can be replaced by a driven member  30 ′. In the illustrated arrangement, the driven member  30 ′ is a square component. In one preferred configuration, the driven member  30 ′ is a 2 inch square component. Other sizes and shapes can also be used. A manual wrench can be used to turn the driven member  30 ′. In some arrangements, the manual wrench can be replaced by a powered wrench, such as a pneumatic, electric or hydraulic wrench for instance, that can be used to turn the driven member  30 ′ such that the valve can be opened and closed. 
   The shaft  32  extends through a protective sleeve  34 . The inner surface of the sleeve  34  is spaced from the shaft  32  by a suitable distance. The sleeve  34  is designed to be buried in the ground and can be formed of any suitable material. In some applications, the sleeve  34  is formed of steel tubing. The length of the sleeve  34  depends, in large measure, upon the length of the shaft  32 . The shaft  32  can have any desired length and can be supported within the sleeve  34  in any suitable manner, if needed. 
   A lower end of the illustrated sleeve  34  comprises a coupling housing  36 . While not illustrated, the coupling housing accommodates a coupling between the shaft  32  and an input shaft of a gearing assembly  40 . Any suitable coupling can be used. In some configurations, the coupling can be omitted and the shaft  32  can be an input shaft  38  of the gearing assembly  40 . 
   With reference now to  FIG. 3 , the input shaft  38  of the gearing assembly  40  can comprise a worm gear. The worm gear can be designed to mesh with a suitably sized gear  42 . The gear  42  can be keyed or otherwise suitably secured to an output shaft  44 . The output shaft  44  can be coupled with a valve shaft  46  in any suitable manner. In some configurations, the output shaft  44  can be the valve shaft  46 . The valve shaft  46  carries the occluding element  50  of the valve  24  such that rotation of the valve shaft  46  results in movement of the occluding element  50  of the valve  24 . In some applications, the occluding element  50  can be a plug or a ball. Other suitable configurations also can be used. 
   Other types of actuators also can be used. For instance, a slotted lever type of actuator can be used where a slider nut moves along a screw rod that is coupled to the shaft  32  and the slider nut moves inside a yoke defined in a lever such that as the slide nut moves down the screw rod and within the yoke, the lever rotates the valve shaft to which it is joined. Another configuration makes use of a dual link in which one of two links translates along the screw rod due to rotation of the screw rod and as one end of the first link translates, the second link turns the valve shaft through its quarter-turn sweep. These constructions and others are well known and any other suitable configurations also can be used, 
   Each of the components described above are well known and further details of these components do not need to be described to enable one of ordinary skill in the art to make and use the present invention. 
   As illustrated, the position indicator  26  comprises three main components: a dial indicator  50 , a drive link  52  between the dial indicator  50  and the valve shaft  46  and a protective housing  54  for the drive link  52 . Unless otherwise apparent, the term valve shaft as used herein should be construed broadly to include any shafts (e.g.,  44 ) that are directly coupled to the true valve shaft (e.g.,  46 ), such as by a spline coupling, a pin coupling or any other suitable coupling keeping in mind the goal of joining a remote dial indicator  50  to the valve shaft  46  such that the true rotational orientation of the valve shaft  46  can be identified even if the actuator assembly fails. 
   With reference now to  FIG. 4 , the drive link  52  is secured to the valve shaft  44 ,  46  such that the drive link  52  will rotate directly with the rotation of the valve shaft  44 ,  46 . The valve shaft  44 ,  46  is mounted within a housing  60 . The housing  60  preferably comprises an access opening  62  that allows access to the valve shaft  44 ,  46 . A cover plate  64  can be removably positioned over the opening  62 . In some applications, an interface between the cover plate  64  and the housing  60  is substantially sealed to reduce the likelihood of fluid infiltrating into the gearing assembly  40 . In the illustrated arrangement, a plurality of threaded fasteners  66  can be used to secure the cover plate  64  to the housing  60 . 
   The cover plate  64  can comprise a recessed portion  70  on one side and a threaded coupling  72  on the opposite side. The recessed portion  70  defines a coupling chamber together with the housing  60 . The recessed portion  70  can be sized and configured to readily accommodate a mounting fixture  74 . The illustrated mounting fixture  74  comprises a threaded post  76  and a positioning flange  78 . The threaded post  76  can be threaded into a female threaded aperture formed along the centerline of the valve shaft  44 ,  46 . Preferably, the threaded post  76  is tightened into the valve shaft  44 ,  46  until the flange  78  abuts the end of the valve shaft  44 ,  46 . Once the mounting fixture  74  is suitably positioned in the valve shaft  44 ,  46 , one or more roll pin  80  or other keying component can be inserted through the flange  78  and into the valve shaft  44 ,  46 . In one configuration, the apertures into which the pin  80  is inserted are formed after the mounting fixture  74  is threaded into the valve shaft  44 ,  46  (e.g., the apertures are drilled through the flange  78  and into the shaft  44 ,  46 ). 
   Other suitable techniques for securing the mounting fixture  74  to the valve shaft  44 ,  46  also can be used. For instance, but without limitation, the mounting fixture  74  can be nitrogen press fit into the valve shaft  44 ,  46 . Desirably, even in such configurations, the mounting fixture  74  still is pinned into position at an eccentric location relative to the rotational axis to reduce or eliminate the likelihood that the mounting fixture will rotate relative to the valve shaft. 
   The drive link  52  can have any suitable configuration. In one assembly, the drive link  52  is a braided cable that resists torsional deflection. For example, a cable such as that used for a speedometer can be used. A distal end  82  of the drive link  52  can be coupled to the mounting fixture  74  in any suitable manner. In some configurations, the distal end  82  slips over a portion of the mounting fixture  74  such that the rotation of the mounting fixture  74  will cause rotation of the drive link  52 . For instance, the mounting fixture  74  can comprise a hexagonal, square or the like protrusion to which a corresponding sleeved component of the drive link  52  can be mounted. In the illustrated configuration, the mounting fixture  74  comprises a splined aperture  84  and the ultimate distal end of the drive link  52  comprises a corresponding splined tip  86 . With the tip  86  inserted into the aperture  84 , the drive link  52  will rotate together with the mounting fixture  74 , which rotates with the valve shaft  44 ,  46 . 
   Any suitable configuration for securing the coupling between the mounting fixture  74  and the drive link  52  can be used. In one configuration, a snap ring can be positioned within a groove to lock the tip  86  of the drive link  52  in position. In another configuration, a set screw can be used to secure the end of the drive link  52  to the mounting fixture  74  (e.g., where the drive link  52  slips over the mounting fixture  74 ). In the illustrated configuration, a threaded sleeve  88  both joins the protective housing  54  to the cover plate  64  and secures the axial position of the tip  86 . Preferably, sufficient clearance is maintained between an enlarged portion of the tip  86  and the sleeve  88  to allow relatively free rotation of the drive link  52 . As shown, the ultimate distal end of the housing  54  comprises a flange  90  and the flange is captured by the threaded sleeve  88 . The flange  90  also bears against a proximal end of the distal tip  86  such that the tip  86  is axially secured relative to the mounting fixture  74 . 
   The protective housing  54  can be formed in any suitable manner. In one configuration, the protective housing  54  is formed of bendable stainless steel tubing. Other suitable materials also can be used. In one configuration, the protective housing  54  is sized to allow relatively free rotation of the drive link  52  within the protective housing  54 . 
   The dial indicator  50  can be mounted in any suitable manner and at any suitable location. In the illustrated arrangement, the dial indicator  50  is mounted to a bracket  100 . The bracket  100  is welded or otherwise suitably secured to the sleeve  34 . The dial indicator can be mounted to the bracket  100  in any suitable manner and the techniques with which automotive gauges are mounted can be used. 
   A proximal end  102  of the housing  54  is coupled to at least one of the dial indicator  50  and the bracket  100 . In the illustrated arrangement, a fitting  104  is secured to the dial indicator  50  and/or the bracket  100  and the proximal end  102  of the housing  54  is coupled to the fitting  104 . The proximal end of the drive link  52  is connected to the needle or other indicator element in any suitable manner. 
   The fitting  104  comprises a capped port  106 . The capped port  106  preferably comprises a threaded opening and a plug or cap. While not clearly shown in the present drawings, the port  106  is fluidly connected to the housing of the gear assembly  40  through the housing  54 . The fluid connection allows a user to remove the cap and check for fugitive emissions from the pipe line in which the assembly  20  has been installed. Thus, the assembly  20  advantageously provides a reliable position indicator as well as a method of checking for fugitive emissions. 
   While the illustrated configuration comprises a dial indicator  50 , it is contemplated that a digital readout also can be used. Furthermore, similar to the digital readout, a sensor can be used to detect the valve position and the sensor can broadcast or otherwise transmit output identifying the valve and the respective valve position. Moreover, in some configurations, the indicator  50  can be replaced by a green/black/red indicator that is black when the valve is between positions but green when it is open and red when it is closed. Other colors or indicators also can be used. 
   In use, once the assembly has been installed, a user operates the valve through any suitable actuator. As actuator turns the valve shaft, a direct reading of the actual rotational orientation of the valve shaft (and therefore the valve) can be obtained. In addition, the gear box can be checked for fugitive emission through the breather port. 
   Although the present invention has been described in terms of a certain embodiment, other embodiments apparent to those of ordinary skill in the art also are within the scope of this invention. Thus, various changes and modifications may be made without departing from the spirit and scope of the invention. For instance, various components may be repositioned as desired. Moreover, not all of the features, aspects and advantages are necessarily required to practice the present invention. Accordingly, the scope of the present invention is intended to be defined only by the claims that follow.