Abstract:
A valve operator is provided having a rotatable spindle extending along an axis. The rotatable spindle is rotatable about the axis. The rotatable spindle is additionally pivotable about a first pivot point. A pivotable linkage operably couples with the spindle. The pivotable linkage is pivotably movable about a second pivot point, such that rotation of the spindle moves the pivotable linkage in a pivoting motion about the second pivot point. Rotation of the spindle additionally pivotally moves the spindle about the first pivot point. The inventive valve operator has a fewer number of parts, a relatively low cost of manufacture, and a high operating efficiency relative to known valve operators.

Description:
FIELD OF THE INVENTION 
     The present invention relates to control valves, and more particularly to a valve operator for manually operating a control valve. 
     BACKGROUND OF THE INVENTION 
     Flow control valves, including plug valves, are used in a number of different applications. Some guiding principles in designing and implementing control valves include the desire to employ a simple and efficient valve and operator having a relatively low number of parts, with the assembled valve being cost effective, efficient, and reliable in operation. 
     Current implementations of control valves often utilize an automated actuator to actuate the control valve. The automated actuator can have a pneumatic or electric source of power. 
     The possibility of the control valve actuator failing at some point during its lifetime varies with each control valve. Because the possibility exists, it is desirable in many instances to provide a manual backup valve operator, or an auxiliary valve operator, to duplicate the function of the automated valve actuator during a failure. The valve operator can also be used in instances where the automated valve actuator is properly functioning, and for other reasons (such as manual override), it is desirable to have the ability to open and close a control valve without using the actuator. 
     SUMMARY OF THE INVENTION 
     There is a need in the art for a valve operator having a fewer number of parts, a relatively low manufacturing cost, and a high operating efficiency relative to known valve operators in use today. The present invention is directed toward further solutions to address this need. 
     In accordance with one example embodiment of the present invention, a valve operator includes a rotatable spindle extending along an axis. The rotatable spindle is rotatable about the axis. The rotatable spindle is additionally pivotable about a first pivot point. A pivotable linkage operably couples with the spindle. The pivotable linkage is pivotably movable about a second pivot point, such that rotation of the spindle about the axis moves the pivotable linkage in a pivoting motion about the second pivot point. Rotation of the spindle can additionally pivotally move the spindle about the first pivot point. 
     The valve operator can be mounted in combination with an automated valve actuator on the same control valve. The automated valve actuator can have a number of different power sources, including pneumatic and electronic. 
     In accordance with one aspect of the present invention, a bearing forms the first pivot point. A reaction force from the pivotable linkage can push a first end of the spindle against the bearing. A structure fixed to a yoke of an actuator coupled to the valve operator supports the bearing. 
     According to another aspect of the present invention, a support bracket for supporting the pivotable linkage is fixed to a yoke of the actuator. The support bracket includes a first bracket arm and a second bracket arm. Each of the first and second bracket arms can extend to the second pivot point from the yoke of the actuator. 
     In accordance with further embodiments of the present invention, the pivotable linkage generally forms about a 90° angle between each of first and second ends and the pivot point. Alternatively, the pivotable linkage can form greater than or less than about a 90° angle between each of first and second ends and the second pivot point. 
     In accordance with still another aspect of the present invention, a pivot pin extending through a pivot bore within the pivotable linkage forms the second pivot point. In addition, a threaded fixture operably coupling the rotatable spindle with the pivotable linkage mounts within a bore of a first end of the pivotable linkage. A bearing mounted within the bore supports the threaded fixture. The threaded fixture can take the form of a nut, in addition to other structures. 
     In accordance with still further aspects of the present invention, the threaded fixture rotatably mounts in a manner enabling the rotation of the threaded fixture about a rotation axis perpendicular to the axis of the threaded spindle and parallel to a rotation axis of the second pivot point. This arrangement allows the threaded fixture to be pivotable about the first pivot point, wherein the first pivot point is distal from the threaded fixture. 
     In accordance with still another aspect of the present invention, a second end of the pivotable linkage extends to couple with a stem. The stem can be an actuator stem or a valve stem. The actuator stem and valve stem can likewise couple together. 
     In accordance with still another aspect of the present invention, a rounded tip is disposed at a first end of the threaded spindle. The rounded tip facilitates the pivoting and rotating movements of the threaded spindle. 
     In accordance with still another aspect of the present invention, a wheel is disposed at a second end of the threaded spindle for actuating a rotation force on the threaded spindle. 
     In accordance with yet another embodiment of the present invention, a pivotable lock nut is disposed to receive the threaded spindle. The lock nut is disposed to lock the threaded spindle to prevent rotation. 
     In accordance with still another embodiment of the present invention, a valve operator is provided having a rotatable threaded spindle. The spindle extends along an axis and is rotatable thereabout. The spindle is pivotable about a first pivot point. A pivotable linkage having a first end, a second end, and a second pivot point is also provided. A bore extends at least partially through the first end of the linkage. A threaded fixture rotatably mounts at the bore for receiving the threaded spindle. The threaded fixture is rotatable about an axis parallel to an axis of the second pivot point. The second end of the pivotable linkage couples to a stem, such that rotation of the spindle causes the linkage to pivot about the second pivot point to effect movement of the stem. 
     In accordance with another embodiment of the present invention, a system is provided for actuating a valve. The system includes an automated valve actuator. In addition, a valve operator is provided. The valve operator includes a rotatable spindle having a first end, a second end, and a center line axis extending therebetween. The first end rotatably couples to a bearing and the spindle is pivotable about a first pivot point at the bearing. A pivotable linkage having a first end, a second end, and second pivot point therebetween, is also provided. The first end supports a rotatable threaded fixture that receives the rotatable spindle, and the second end extends to communicate with a stem. 
     The present invention provides a side mounted valve operator. The assembly of the valve operator can be configured so that the pivotable linkage in one mode can push a valve stem downward, and in another mode the assembly can be inverted so the operator pushes a valve stem upward. No additional parts are required between each of the two modes. 
     Furthermore, the present invention provides for a mechanism using manually induced motion and lifting forces applied to valve and actuator stems at a greatly increased mechanical efficiency over known art, and using a reduced number of bearings. Known manual valve operators have at least one additional bearing within the operator mechanism relative to the operator of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The aforementioned features and advantages, and other features and aspects of the present invention, will become better understood with regard to the following description and accompanying drawings, wherein: 
     FIG. 1 is a diagrammatic cross-sectional view of a valve operator in combination with a valve actuator capable of moving an actuator stem in an upward motion according to the teachings of the present invention; 
     FIG. 2 is a cross-sectional view taken at section A—A of FIG. 1 according to the teachings of the present invention; 
     FIG. 3 is a diagrammatic cross-sectional view of a valve operator in combination with an actuator capable of moving an actuator stem in a downward motion according to the teachings of the present invention; 
     FIG. 4 is a cross-section at section B—B of FIG. 3 according to the teachings of the present invention; 
     FIG. 5 is an enlarged diagrammatic illustration of a bearing according to the teachings of the present invention; and 
     FIGS. 6A through 6C are diagrammatic illustrations of motivated linkages according to aspects of the present invention. 
    
    
     DETAILED DESCRIPTION 
     An illustrative embodiment of the present invention relates to a valve operator for use with a control valve. The valve operator includes a handwheel attached to a rotatable and pivotable threaded spindle. The threaded spindle pivots about a first pivot point. Rotation of the handwheel causes a motivated linkage having an extended link portion to pivot about a second pivot point and push against the stem of an actuator. The direction of motion is typically against a spring force from an actuator spring. 
     The threaded spindle engages a nut, which can rotate in a bore within the motivated linkage. A second bore retains a pivot pin, which is further engaged in a support structure, to form the second pivot point. The support structure fastens to a yoke of the actuator. The reaction force applied to the threaded spindle as a result of the turning of the handwheel is absorbed by a needle-bearing, which is supported within a portion of the structure. 
     The nut moves along the spindle and makes a radial excursion around the second pivot point as the threaded spindle rotates and pivots. A spherical tip on the end of the spindle, which seats in the bearing, facilitates the pivotal movement in addition to the rotational movement. 
     The components of the valve operator can be inverted to push a valve stem downward rather than pushing the valve stem upward. The overall operator design utilizes a reduced number of parts, thereby reducing the overall cost. The components of the operator are reversible without the use of additional parts, and the low friction of the pivoted and rotating spindle unit, together with a lower number of bearings, provides a high operating efficiency. 
     FIGS. 1 through 6C, wherein like parts are designated by like reference numerals throughout, illustrate example embodiments of a valve operator according to the teachings of the present invention. Although the present invention will be described with reference to the example embodiments illustrated in the figures, it should be understood that many alternative forms can embody the present invention. One of ordinary skill in the art will additionally appreciate different ways to alter one or more parameters of the embodiments disclosed, such as the size, shape, or type of elements or materials, in a manner still in keeping with the spirit and scope of the present invention. 
     FIG. 1 is a diagrammatic cross-sectional view of a valve operator  10  in accordance with one embodiment of the present invention. A force generator or handwheel  12  is provided for applying a rotational force to a threaded spindle  24 . The invention is not limited to the handwheel  12  for providing the rotational force to the threaded spindle  24 . Alternative mechanisms such as differently shaped levers, an additional automated actuator, a belt and pulley system, or the like, that can generate the requisite rotational force, can be used instead of the illustrated handwheel  12 . 
     The threaded spindle  24  couples to a motivated linkage  14  by way of a rotatable nut  26 . The nut  26  rotatably mounts within a first bore  28  of the motivated linkage  14 . Internal threads of the nut  26  engage with the threads of the threaded spindle  24 . The rotatable nut  26  can take the form of a number of different structures having a threaded internal passage for receiving the threaded spindle  24  and a fitting, or able to be coupled with a fitting, for rotatable mounting within the first bore  28 , as understood by one of ordinary skill in the art. 
     The motivated linkage  14  further includes a second bore  30  having a pivot pin  32  passing therethrough. The motivated linkage  14  also includes an extended link  16  that couples with an actuator stem  18  of an actuator  20 . The extended link  16  can couple with the actuator stem  18  in a number of different ways, such as by using different fastening devices, pins, bearings, fixtures, or simply pressing against the actuator stem  18  when applying a force thereon. The actuator stem  18  can connect with a valve stem  22  to enable the motivated linkage  14  to effect movement of the valve stem  22  as later described herein. 
     A support structure  34  connected to an actuator yoke  36  supports the valve operator  10 . The support structure  34  can be fixedly attached to the actuator yoke  36  by a number of different fastening methods, including adhesive, welding, riveting, clamping, bolting, screwing, or the like. The support structure  34  is able to withstand the weight of the valve operator  10  assembly, as well as the reaction forces generated by the operator  10  as the threaded spindle  24  pushes against a needle bearing  38 , and as the motivated linkage  14  moves the actuator stem  18 . 
     The threaded spindle  24  includes a generally spherical tip  40 , which mounts in the needle-bearing assembly  38 A supported by the support structure  34 . The spherical tip  40  of the threaded spindle  24  allows for either or both rotational and pivotal motion of the threaded spindle  24 . 
     A lock nut  46 , couples to a spherical portion of the motivated linkage  14 , and serves to prevent movement of the threaded spindle  24  when not in use. The lock nut  46  has an internal thread that engages with the thread of the threaded spindle  24 . The lock nut  46  additionally has a perimeter profile that matches the perimeter profile of the motivated linkage  14 , such that the lock nut  46  can slide along the perimeter edge of the motivated linkage  14  when not in a locked position. If a user desires to lock the threaded spindle  24  in a particular arrangement, the user rotates the lock nut  46  to compress the lock nut  46  against the perimeter edge of the motivated linkage  14 , which prevents rotational and pivotal movement of the threaded spindle  24  as well as pivotal movement of the motivated linkage  14 . 
     FIG. 2 is a cross-sectional illustration of the valve operator  10  taken along section A—A of FIG.  1 . The support structure  34  of FIG. 1 supports the threaded spindle  24  and the nut  26 . The support bracket  34  includes a pair of arms  48  extending from the actuator yoke  36 . However, the support bracket  34  can have a number of different configurations extending between the actuator yoke  36  and the nut  26 . For example, the support bracket  34  can have a different number, and differently shaped, arms  48  where the arms can be relatively straight, curved, angled, or the like. The arms can be solid, or can contain a series of openings to reduce the weight of the support bracket  34 . Other support bracket configurations are possible as will be understood by one of ordinary skill in the art. 
     FIG. 2 also provides a cross-sectional top view of the coupling connection between the handwheel  12 , the threaded spindle  24 , and the nut  26 . As can be seen, the threaded spindle  24  passes through the nut  26  and terminates at the needle-bearing  38  in the form of the spherical tip  40 . The needle-bearing  38  receives the spherical tip  40  in a seat and allows for the rotation and pivoting of the threaded spindle  24 . Also visible in this view is the pivot pin  32 . 
     The support bracket  34  mounts to the actuator yoke  36  and is affixed thereto with bolts  50 , which hold the support bracket  34  fixedly in place. The support bracket  34  can mount in a number of additional ways, including adhesive, welding, riveting, or the like. 
     FIG. 2 also illustrates the extended link  16  being coupled with the actuator stem  18 . A pair of pins  54  forms the connection between the extended links  16  and the actuator stem  18 . However, one of ordinary skill in the art will understand that any number of different mechanical couplings can couple the extended link  16  of the motivated linkage  14  with the actuator stem  18 . 
     FIG. 3 illustrates an alternative embodiment of the valve operator  10 ′ in accordance with the teachings of the present invention. Like parts are designated with like reference numerals. The embodiment illustrated is an inverted form of the embodiment shown in FIGS. 1 and 2. The handwheel  12  couples with the threaded spindle  24 , which terminates in the spherical tip  40  seated within the needle-bearing  38 . The threaded spindle passes through the nut  26 , which mounts within the first bore  28  of the motivated linkage  14 . Rotation of the handwheel  12  causes the motivated linkage  14  to travel along the length of the threaded spindle  24 , while pivoting about a pivot point formed by the second bore  30  and the pivot pin  32 . 
     FIG. 4 illustrates a cross-sectional view of the valve operator  10 ′ taken at section B—B of FIG.  3 . As illustrated herein, the handwheel  12  couples with the threaded spindle  24 . The spindle  24  passes through the threaded nut  26 . The support bracket  34  has a slotted portion  55  to receive the motivated linkage  14 , and fixedly mounts to the yoke  36  of the actuator with the use of two bolts  50 . The pins  32  pass through the slotted portion  55 , allowing the motivated linkage  14  to rotate about the shared axis of the pins  32 . In addition, the pins  54  couple the extended link  16  of the motivated linkage  14  to the actuator stem  18 . 
     The valve operator  10  of FIGS. 1 and 2 pushes the actuator stem  18  upward with movement of the handwheel  12 , while the arrangement valve operator  10 ′ illustrated in FIG. 3 pushes the actuator stem  18  downward with rotation of the handwheel  12 . Each component of the valve operator can be rearranged into the valve operator  10 ′ configuration of FIG. 3 without requiring any modification to the actual components. The specific arrangement of operator components relates to the direction of the spring force on the actuator stem  18 . If the actuator stem  18  experiences a constant spring force pushing the actuator stem  18  downward, the valve operator configuration of FIGS. 1 and 2 is appropriate. If the actuator stem  18  experiences a constant spring force pushing the actuator stem  18  upward, the valve operator configuration of FIG. 3 is appropriate. The direction of the spring force is determined as a specification of the particular valve construction, and typically makes use of a valve spring (not shown) surrounding the actuator stem  18 , or the valve stem  22 , as is understood by those of ordinary skill in the art. 
     FIG. 5 illustrates a close-up of the needle bearing assembly  38 A illustrated in FIGS. 1 and 3. The needle bearing assembly  38 A includes a screw  42 , which screws into the spherical tip  40  of the threaded spindle  24 . The screw  42  holds the spherical tip  40  of the threaded spindle  24  in place during times at which the valve operator  10  is not connected to the actuator, and/or there is no force pressing the threaded spindle  24  against the needle-bearing  38 , i.e., during shipping. The needle bearing  38  further receives a base  43  coupled with a cap  39  that is part of the support bracket  34 . When the valve operator  10  is coupled with an actuator, the reaction force of a properly installed motivated linkage  14  pushes the spherical tip  40  of the threaded spindle  24  towards, or into base  43  and therefore compresses the bearing  38 . Thus, there is no need for the screw  42  to withstand any pulling load from the threaded spindle  24 . 
     FIGS. 6A,  6 B, and  6 C illustrate several embodiments of the motivated linkage  14  in accordance with the teachings of the present invention. The illustrated linkage includes the first bore  28 , the second bore  30 , and the extended link  16 . The angle between the extended link  16  to the second bore  30  and the second bore  30  up to the first bore  28  is approximately 90° in FIG.  6 A. However, in FIG. 6B the angle is an obtuse angle (i.e., approximately greater than 90°), while the angle in FIG. 6C is an acute angle (i.e., less than approximately 90°). One of ordinary skill in the art will understand that varying the angle of the linkage will have different affects on the power and range of the motivated linkage  14 . In addition, one of ordinary skill in the art will appreciate that the motivated linkage  14  can have a number of different shapes and angles in addition to those depicted herein. FIGS. 6A through 6C illustrate the underlying angular relationship possibilities between each end of the motivated linkage, regardless of the actual linkage shape. 
     In operation, the valve operator  10  works generally as follows in accordance with the teachings of the present invention. Referring to FIG. 1, a user rotates the handwheel  12  in either a clockwise or a counterclockwise direction, depending on the desired movement of the actuator stem  18 . Rotation of the handwheel  12  rotates the threaded spindle  24  and causes the nut  26  to travel along the axis of the threaded spindle  24 , and at the same time move along an arcuate path defined by the distance between the pin  32  and the bearing  26 , where the axis of the pin  32  is the focal point. The movement of the nut  26  through the arcuate path in turn causes the axis of the spindle  24  to be angularly displaced. The angular displacement is enabled by a rotation about a pivot point at the spherical tip  40 . Rotation of the handwheel  12  in one direction moves the nut  26  in one direction, and rotation in the other direction moves the nut  26  in the opposite direction. The nut  26  couples with the first bore  28  of the motivated linkage  14 . Therefore, movement of the nut  26  results in movement of the motivated linkage  14 . For example, if rotation of the handwheel  12  results in the nut  26  traveling in the direction toward the handwheel  12 , the nut  26  moves the motivated linkage  14  in that direction. 
     The motivated linkage  14  is also pivotally mounted at the second bore  30  with the pivot pin  32  to form a first pivot point. The force generated by the nut  26  pivots the motivated linkage in a clockwise direction about the pivot pin  32 . The clockwise rotational movement of the motivated linkage  14  causes the extended link  16  to push up against the actuator stem  18 , vertically lifting the actuator stem  18  and the valve stem  22  coupled thereto. The vertical action of the actuator stem  18  opens or closes a valve. The valve is not illustrated for purposes of clarity. One of ordinary skill in the art will understand that a number of different valves can connect with the type of actuator illustrated herein, such as gate valves, plug valves, and needle valves. 
     When the manual valve operator  10  is not in use, and the automated actuator  20  is in use, the actuator  20  automatically lifts the actuator stem  18  off the extended link  16 . Thus, the motivated linkage  14  does not interfere with automated movement of the actuator stem  18  and the corresponding movement of the valve stem  22  to open and close the valve. Locking the nut  46  can lock the motivated linkage  14  in place to prevent interference from the valve operator  10 . 
     The valve operator  10  in the configuration depicted in FIG. 3 is useful for implementation with a valve actuator  20  having a spring normally pulling the actuator stem  18  in an upward direction. In such an arrangement, the actuator  20  and the motivated linkage  14  each push in a opposite, downward, direction on the actuator stem  18  to open and close the valve attached thereto. 
     Referring again to FIG. 1, as the motivated linkage  14  rotates in a clockwise direction, the motivated linkage  14  at the location of the first bore  28  and the nut  26  moves along an arcuate path. In order for such a path to occur, the threaded spindle  24  pivots about a pivot point generally located at the spherical tip  40 . Therefore, as the motivated linkage  14  moves along the arcuate path, the threaded spindle  24  pivots downward to follow the path. The threaded spindle is provided with the spherical tip  40  to allow the pivotal movement to occur. Further, the nut  26  rotates within the first bore  28  to maintain alignment with the threaded spindle  24  and allow the threads to engage appropriately. 
     The lock nut  46  is additionally provided to lock the threaded spindle in place against the motivated linkage  14 . To lock the operator in place, the lock nut is tightened, which results in a friction force between the lock nut and the edge of the motivated linkage  14 . The friction fit prevents the pivotal movement of the threaded spindle  24 , as well as the rotational movement of the threaded spindle  24 . The lock nut  46  must be loosened and removed a sufficient distance from the motivated linkage  14  so as to not interfere during the normal operation and use in the range of movement of the motivated linkage  14 . 
     The valve operator according to the teachings of the present invention offers a unique arrangement of linkages and a spindle to achieve a cost effective and efficient design for movement of a valve actuator and stem with a minimum amount of friction. The components of the valve operator are reversible, such that the same parts can be used in an upward force-generating configuration or a downward force-generating configuration by simply re-arranging individual components. Movement of the handwheel, or some other source of rotational force, causes the threaded spindle to rotate and slightly pivot as the motivated linkage moves to motivate the actuator stem and open or close the attached valve. 
     Numerous modifications and alternative embodiments of the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode for carrying out the present invention. Details of the structure may vary substantially without departing from the spirit of the present invention, and exclusive use of all modifications that come within the scope of the appended claims is reserved. It is intended that the present invention be limited only to the extent required by the appended claims and the applicable rules of law.