Abstract:
Valve operator having a weighted powering assembly that is substantially supported and balanced on a generally upright elongated key that drivingly engages a rotatable valve nut.

Description:
BACKGROUND OF INVENTION 
     1. Field of the Invention 
     The present invention relates generally to tools for opening and closing (i.e., exercising) valves. In another aspect, the invention concerns power valve operators for exercising valves having valve nuts that turn on a generally upright axis of rotation. 
     2. Description of the Prior Art 
     Many large valves are exercised by rotating a valve nut coupled to the body of the valve. Examples of valves that operate in this manner include valves employed in fire hydrants, underground water lines, water treatment plants, and petroleum product lines. Typically, such valves require a high magnitude of torque to rotate the valve nut. Further, such valves require relatively slow and constant turning of the valve nut in order to prevent damaging pressure surges upstream and downstream of the valve. 
     In the past, a variety of configurations of the manual and power valve operating devices have been employed to exercise valves via rotation of the valve nut. The prior art manual valve operators generally comprise a key for coupling the device to the valve nut and one or more elongated handles for increasing the amount of torque that can be manually applied to the valve nut. Although prior art manual valve operators are relatively inexpensive and portable, such manual devices have a number of drawbacks. For example, manually turning of the valve nut can be a slow and physically exhausting task, especially when the exercised valves require high torque and many rotations of the valve nut. When the valve is being closed in order to terminate flow to a damaged and leaking line, slow manual turning of the valve nut can allow excessive amounts of fluids to escape the leaking line during manual exercising of the valve, thereby risking further damage to the surroundings due to excessive fluid leakage. Physical exhaustion of the workers operating the manual valve operator can increase the risk of injury to the workers and/or increase the risk of worker error during performance of the desired task. When the valve being manually exercised is positioned in a dangerous location (e.g., an underground water valve accessible through a port in a city street), the slow valve-turning required by manual valve operators can increase the exposure of the workers to such dangerous conditions. In addition, the light weight of most manual valve operators creates a need for the workers to continually exert a downward holding force on the key while turning the valve nut in order to prevent disengagement of the key from the valve nut, which can become stripped (i.e., rounded-off) when the valve operator becomes disengaged during turning. 
     Prior art power (i.e., automatic) valve operators are typically mounted on vehicles. Such vehicle-mounted power valve operators can deliver high magnitudes of torque in a relatively rapid and continuous manner while exerting sufficient downward force on the key to maintain engagement of the key and the valve nut. However, vehicle-mounted power valve operators have a number of drawbacks. For example, such vehicle-mounted power valve operators are expensive to purchase and mount on the vehicle. Further, it can be very difficult to properly align the key of a vehicle-mounted power valve operator with the valve nut to be turned, especially when faced with adverse surface conditions such as, for example, snow, mud, and/or ice. 
     The prior art also includes portable (i.e., non vehicle-mounted) power valve operators. Such portable power valve operators typically are fairly lightweight and do not produce a sufficient amount of torque to exercise larger valves. Further, the light weight of these portable devices can cause the key to become disengaged from the valve nut unless a continuous manual downward force is exerted on the key by the workers operating the device. 
     SUMMARY OF INVENTION 
     It is, therefore, an object of the present invention to provide a portable valve operator that minimizes physical fatigue of workers operating the device. 
     A further object of the invention is to provide a power valve operator that can exercise valves more rapidly than manual means. 
     A still further object of the invention is to provide a portable valve operator having sufficient weight to prevent disengagement of the key from the valve nut without requiring application of a manual external downward force to the valve operator. 
     Another object of the invention is to provide a valve operator producing a relatively smooth and slow rotation that prevents pressure surges upstream and downstream of the valve when the valve is exercised. 
     Still another object of the invention is to provide a portable power valve operator operable to generate a sufficient amount of torque to operate large valves. 
     Yet another object of the invention is to provide a power valve operator that facilitates easy manual alignment of the key with the valve nut. 
     Yet still another object of the invention is to provide an improved method of exercising a valve using a power valve operator. 
     It should be understood that the above-listed objects are only exemplary, and not all the objects listed above need be accomplished by the invention described and claimed herein. 
     Accordingly, in one embodiment of the present invention, there is provided a tool for rotating a valve nut. The tool comprises an elongated key, a powering device, and a weighted handle. The key has a first end adapted to matingly engage the valve nut. The powering device includes a housing and a rotation element. The rotation element is drivingly coupled to the second end of the key. The powering device is operable to cause rotation of the rotation element relative to the housing. The handle is rigidly coupled to the housing and extends generally outwardly from the axis of elongation of the key. The handle has a center of gravity that is at least substantially centered on the axis of elongation of the key. 
     In another embodiment of the present invention, there is provided a valve operator for rotating a valve nut of a valve to thereby exercise the valve. The valve operator comprises an elongated key and a powering assembly. The elongated key presents a normally lower end for releasably and matingly engaging the valve nut. The powering assembly presents a rotation element adapted to releasably and matingly engage a normally upper end of the key. The powering assembly includes a powering device and a handle. The powering device is operable to rotate the rotation element relative to the handle. The powering assembly has a center of gravity that is at least substantially centered on the axis of rotation of the rotation element. 
     In still another embodiment of the present invention, there is provided a method of operating a valve having a valve nut that can be rotated on a generally upright axis of rotation to thereby exercise the valve. The method comprises the steps of: (a) coupling a normally lower end of an elongated key to the valve nut; (b) while the key is coupled to the valve nut, coupling a powering assembly to a normally upper end of the key, said powering assembly including a powering device and a handle; and (c) actuating the powering device to thereby cause the key and the valve nut to rotate relative to the handle. 
     In yet another embodiment of the present invention, there is provided a method of operating a valve having a valve nut that can be rotated on a generally upright axis of rotation to thereby exercise the valve. The method comprises the steps of: (a) coupling a key of a power valve operator to the valve nut; (b) substantially aligning the center of gravity of the power valve operator with the axis of rotation of the valve nut; and (c) simultaneously with step (b), using the power valve operator to rotate the valve nut. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     A preferred embodiment of the present invention is described in detail below with reference to the attached drawing figures, wherein: 
     FIG. 1 is a side view of an extendable key being aligned for engagement with a valve nut of an underground water valve; 
     FIG. 2 is a side view of a power valve operator constructed in accordance with the principles of the present invention being used to exercise an underground water valve, particularly illustrating the manner in which the valve operator is positioned over the valve nut and restrained from twisting by workers holding handles of the valve operator; 
     FIG. 3 is a sectional side view of the key that is configured to extend between the valve nut and the powering device during exercising of a valve, particularly illustrating the manner in which the length of the key can be adjusted; 
     FIG. 4 is a top assembly view of the main and auxiliary handles of the valve operator; 
     FIG. 5 is a partial side sectional assembly view of the valve operator handles, particularly illustrating the manner in which the auxiliary handles can be coupled to the main handle; and 
     FIG. 6 is an isometric assembly view showing the manner in which the key, the handle, the torque converter, and the motor of the power operator are interconnected. 
    
    
     DETAILED DESCRIPTION 
     Referring initially to FIG. 1, a worker  10  is illustrated as manually aligning and lowering an elongated key  12  into engagement with a valve nut  14  of a valve  16  that controls flow through an underground water line  18 . As used herein, the term “valve nut” shall denote any element that can mate with a key and causes opening or closing of the valve when rotated relative to the body of the valve. Elongated key  12  includes a first normally lower component  20  and a second normally upper component  22 . First component  20  presents a normally lower end  24  that is adapted to releasably and matingly engage valve nut  14 . Second component  22  presents a normally upper end  26  that is adapted to releasably and matingly engage a rotation element of a powering assembly to be described in detail below. First and second components  20 ,  22  are telescopically interfitted so that the distance between normally lower end  24  and normally upper end  26  can be adjusted by manually manipulating adjustment pin  28  and sliding first and second components  20 ,  22  relative to one another. 
     Referring to FIG. 2, once key  12  is positioned with normally lower end  24  matingly engaging valve nut  14 , a powering assembly  30  can be coupled to normally upper end  26  of key  12 . FIG. 2 shows an assembled inventive power valve operator  31  (comprising key  12  and powering assembly  30 ) positioned for turning valve nut  14  of valve  16 . Powering assembly  30  generally includes a powering device  32  and a handle  34 . Powering assembly  30  is operable to rotate key  12  relative to a handle  34  to thereby turn valve nut  14 . It is preferred for the axis of rotation of valve nut  14  to be substantially vertical and for the axis of elongation of key  12  to be substantially aligned with the axis of rotation of valve nut  14 . It is further preferred for the center of gravity of powering assembly  30  to be substantially centered on the axis of elongation of key  12 . Such a configuration allows key  12  and powering assembly  30  to be substantially balanced on valve nut  14  of valve  16  so that workers  10   a,b  need only maintain the balance in valve operator  31  on valve nut  14  and restrain rotation of valve operator  31  via handle  34  during exercising of valve  16 . 
     In order to ensure that normally lower end  24  of key  12  maintains engagement with valve nut  14 , it is preferred for the total weight of valve operator  31  (i.e., the combined weight of power assembly  30  and key  12 ) to be at least about 75 pounds, more preferably at least about 125 pounds, still more preferably at least about 175 pounds, and most preferably at least 200 pounds. Due to the fact that key  12  must be manually manipulated into engagement with valve nut  14  prior to coupling powering assembly  30  to key  12 , it is preferred for key  12  to be relatively light to facilitate ease of manipulation of key  12  onto valve nut  14 . Preferably, key  12  makes up less than about 75 percent of the total weight of valve operator  31 , more preferably less than about 65 percent of the total weight of valve operator  31 , and most preferably less than 50 percent of the total weight of valve operator  31 . Preferably, key  12  weighs less than about 100 pounds, more preferably less than about 75 pounds, and most preferably less than about 50 pounds. Thus, after key  12  is positioned on valve nut  14 , the bulk of the weight of valve operator  31  can be manually added via the coupling of powering assembly  30  to normally upper end  26  of key  12 . 
     It is preferred for powering assembly  30  to have a weight of sufficient magnitude to ensure that normally lower end  24  of key  12  maintains engagement with valve nut  14 ; however, it is further preferred for the weight of powering assembly  30  to be sufficiently low to allow powering assembly  30  to be manually lifted and placed onto normally upper end  26  of key  12  after key  12  has been set on valve nut  14 . Thus, it is preferred for the weight of powering assembly  30  to be in the range of from about 50 to about 800 pounds, more preferably in the range of from about 75 to about 600 pounds, still more preferably in the range of from about 100 to about 400 pounds, and most preferably in the range of from 150 to 300 pounds. Preferably powering assembly  30  makes up at least about 35 percent of the total weight of power operator  31 , more preferably at least about 50 percent of the total weight of power operator  31 , and most preferably at least 65 percent of the total weight of power operator  31 . In order to prevent fatigue of workers  10   a,b  due to supporting excessive vertical loads, it is preferred for at least about 75 percent of the weight of powering assembly  30  to be supported by key  12 , more preferably at least about 85 percent of the weight of powering assembly  30  is supported by key  12 , and most preferably at least about 90 percent of the weight of powering assembly  30  is supported by key  12  when valve operator  31  is positioned for turning valve nut  14 . The weight of powering assembly  30  supported by key  12  is directly transferred to valve nut  14  to thereby maintain engagement of key  12  and valve nut  14  during exercising of valve  16 . 
     Handle  34  of powering assembly  30  preferably has a center of gravity that is at least substantially aligned with the axis of elongation of key  12 . It is preferred for handle  34  to be weighted to thereby inertially counteract any sudden twisting or tilting of valve operator  31 . Preferably, handle  34  weighs at least about 25 pounds, more preferably at least about 50 pounds, still more preferably at least about 75 pounds, and most preferably at least 100 pounds. Preferably, handle  34  makes up at least about 25 percent of the total weight of power operator  31 , more preferably at least about 35 percent of the total weight of power operator  31 , and most preferably at least 50 percent of the total weight of power operator  31 . 
     Referring to FIG. 3, first component  20  of key  12  preferably defines a generally non-circular channel  36  within which second component  22  can be telescopically received. It is preferred for the outer surface of second component  22  to substantially match the generally non-circular shape of channel  36  so that relative twisting of first and second components  20 ,  22  is restrained. Preferably, channel  36  has a substantially equilateral polygonal shape, most preferably a substantially square shape. Second component  22  can include a plurality of adjustment holes  38  that allow the axial position of first and second components  20 ,  22  to be adjusted and fixed via manual manipulation of adjustment pin  28  in different adjustment holes  38 . Normally lower end  24  defines a first socket  40  that is adapted to matingly and releasably engage valve nut  14 . Normally upper end  26  defines a second socket  42  adapted to matingly and releasably engage a rotation element of powering assembly  30 . It is preferred for key  12  to be adjustable up to a maximum length (i.e., maximum distance between normally lower end  24  and normally upper end  26 ) of at least about five feet, more preferably at least about eight feet, and most preferably at least 10 feet. 
     Referring to FIG. 4, main handle  34  includes an elongated first portion  44  and an elongated second portion  46  each extending in generally opposite directions from a splined opening  48  extending through handle  34 . Referring to FIGS. 4 and 5, first and second auxiliary handles  50 ,  52  are configured to be coupled to main handle  34  in situations where more weight is required to force valve operator  31  down onto valve nut  14  or where more workers are required to resist twisting of valve operator  31 . First auxiliary handle  50  can be releasably coupled to main handle  34  by placing a first connection fork  54  over main handle  34 , extending a first connection bolt  56  through first auxiliary connection holes  58  and first main connection hole  60 , and tightening first connection nut  62  onto first connection bolt  56 . Second auxiliary handle  52  can be releasably coupled to main handle  54  by placing a second connection fork  64  over main handle  34 , extending a second connection bolt  66  through second auxiliary connection holes  68  and second main connection hole  70 , and tightening second connection nut  72  on second connection bolt  66 . It is preferred for first and second auxiliary handles  50 ,  52  to extend in generally opposite directions that are at least substantially perpendicular to the direction of extension of first and second portions  44 ,  46  of main handle  34 . Preferably, each of first auxiliary handle  50 , second auxiliary handle  52 , first portion  44 , and second portion  46  has a length in the range of from about two to about eight feet, more preferably in the range of from about three to about six feet, and most preferably in the range of from 3.5 to 4.5 feet. 
     Referring to FIG. 6, powering device  32  is illustrated as comprising a motor  74  and a torque converter  76 . One example of a commercially available device that can be employed as powering device  32  is known in the art as a “nutrunner.” Suitable nutrunners are manufactured by ROTORTOOL® and are available from Cooper Tools, Lexington, S.C. Motor  74  includes an output shaft  78  providing substantially high speed and low torque rotary output. Motor  74  can be either a hydraulic, pneumatic, or electric motor. Preferably, motor  74  is a pneumatic motor powered via air supplied through air supply hose  80 . The speed and torque of motor  74  can be controlled via signals transmitted through a control line  82 . In an alternative embodiment of the present invention, motor  74  can be replaced with a combustion engine. 
     Torque converter  76  has a housing  86  that is rigidly coupled to the housing of motor  74 . Torque converter  76  also includes internal torque conversion components that are coupled to output shaft  78 . Torque converter  76  is operable to increase the torque and reduce the speed of the rotary output from output shaft  78 . The resulting low speed, high torque rotary output of torque converter  76  is conveyed via a rotation element  84  which rotates relative to housing  86  of torque converter  76 . It is preferred for powering device  32  (i.e., motor  74  and torque converter  76 ) to be operable to produce at least about 500 foot-pounds of torque between housing  86  and rotation element  84 , more preferably at least about 750 foot-pounds of torque, still more preferably at least about 1,000 foot-pounds of torque, and most preferably at least 1,250 foot-pounds of torque. It is preferred for powering device  32  to be operable to rotate rotation element  84  relative to housing  86  at a speed in the range of from about 0.5 to about 40 rpm while delivering the required amount of torque, more preferably a speed in the range of from about 1.0 to about 20 rpm, and most preferably a speed in the range of from 5 to 15 rpm. 
     Handle  34  can be easily coupled and decoupled from powering device  32 . To couple handle  34  to powering device  32 , splined opening  48  in handle  34  is placed over a corresponding splined projection  88  of housing  86  and against a flange  90  of housing  86 . A female threaded collar  92  can then be threaded onto a corresponding male threaded projection  94  of housing  86  and tightened into contact with main handle  34  to thereby secure handle  34  between collar  92  and flange  90 . To couple powering device  32  to normally upper end  26  of key  12 , rotation element  84  can be inserted into second socket  42  (shown in FIG. 3) of normally upper end  26  to form a releasable mating connection that restricts relative rotation of key  12  and rotation element  84 . Typically the weight of powering assembly  30  is sufficiently large to maintain engagement of rotation element  84  and upper end  26  of key  12  when valve operator  31  is positioned for rotating valve nut  14  (see FIG.  2 ). However, if it is desired to further secure the connection between key  12  and rotation element  84 , a pin (not shown) can be inserted through a hole  96  in normally upper end  26  of key  12  and through an opening  98  in rotation element  84 , thereby locking key  12  and rotation element  84  into engagement with one another. 
     Referring now to FIGS. 1 and 2, in operation, key  12  is manually coupled to valve nut  14  so that rotation of key  12  causes corresponding rotation of valve nut  14 . The length (i.e., height) of key  12  can then be adjusted so that upper end  26  of key  12  is at an appropriate height for placement of powering assembly  30  thereon. Powering assembly  30  is then placed on and coupled to normally upper end  26  of key  12  by inserting rotation element  84  (shown in FIG. 6) into second socket  42  (shown in FIG.  3 ). In such a configuration (shown in FIG. 2) the axis of rotation of valve nut  14 , the axis of elongation of key  12 , the axis of rotation of rotation element  84 , and the center of gravity of powering assembly  30  are all substantially vertically aligned. This vertical alignment and weight distribution allows the center of gravity of valve operator  31  to be positioned over valve nut  14  so that valve operator  31  is substantially balanced on valve nut  14  during exercising of valve  16 . Prior to rotating valve nut  14 , motor  74  of powering assembly  30  must be coupled to a power source  100  (such as an air compressor) that provides power to motor  74  via air supply hose  80 . Handle  34  of powering assembly  30  can then be grasped by workers  10   a,b . While handle  34  is manually grasped by workers  10   a,b , worker  10   b  can depress a foot actuator  102  that is connected to motor  74  via control line  82 . Foot actuator  102  is operable to actuate motor  74 , thereby causing rotation of key  12  relative to handle  34 . Foot actuator  102  can also include controls for varying the speed and torque of powering device  32 . While valve operator  31  is employed to rotate the valve nut  14 , worker  10   a  can monitor a pressure gauge  103  disposed in air supply hose  80  to ensure that proper air pressure is supplied to motor  74 . Further, during operation of valve operator  31 , worker  10   b  can monitor the torque, speed, and number of revolutions of key  12  relative to handle  34  via a torque gauge  104 , an rpm gauge  106 , and an automatic resettable cycle counter  108 , respectively. 
     The preferred forms of the invention described above are to be used as illustration only, and should not be used in a limiting sense to interpret the scope of the present invention. For example, although FIGS. 1 and 2 illustrate the exercised valve as being an underground water line valve, it is entirely within the ambit of the present invention for the valve operator to be used to exercise above-ground valves such as, for example, valves employed in fire hydrants, water treatment plants, or petroleum product lines. Obvious modifications to the exemplary embodiments, set forth above, could be readily made by those skilled in the art without departing from the spirit of the present invention. 
     The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.