Patent Publication Number: US-11024477-B2

Title: Current interrupter for high voltage switches

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims benefit to U.S. Non-Provisional application Ser. No. 15/670,485, filed Aug. 7, 2017, which claims benefit to U.S. Non-Provisional application Ser. No. 14/175,465 filed on Feb. 7, 2014, which claims benefit to U.S. Provisional Application No. 61/762,579 filed on Feb. 8, 2013, the disclosures of which is incorporated herein by reference for all purposes. 
    
    
     FIELD OF THE APPLICATION 
     This application relates to an improved current interrupter, and particularly, an improved current interrupter for integration with a high voltage air switch including a compartmentalized housing design for isolating an operating mechanism from one or more vacuum bottle interrupters. 
     FIELD 
     Conventional current interrupters comprise one or more serially connected vacuum bottles. Each vacuum bottle houses a pair of contacts that are separated or contacted in order to open or close the circuit. These contacts in the vacuum bottles are opened and closed by a bi-stable mechanism located at one end of the current interrupter. 
     For conventional current interrupters, the vacuum bottles and bi-stable mechanism are contained within a single housing filled with a pressurized gas. The gas isolates the vacuum bottles from the environment, for example, to protect from moisture, which is a recognized problem for vacuum bottles. However, as the bi-stable mechanism is operated with a rotary shaft that extends through the housing, it can be difficult to effectively seal this portion of the housing. 
     Accordingly, a need exists for a vacuum interrupter with an improved housing for isolating the vacuum bottles from the environment. 
     SUMMARY 
     The present application provides a vacuum interrupter including a compartmentalized housing design for isolating an operating mechanism from one or more vacuum bottle interrupters. The vacuum interrupter includes a vacuum bottle housing having an interior and an exterior, and at least one vacuum bottle positioned within the interior of the vacuum bottle housing. The at least one vacuum bottle includes axially separable contacts within it, including at least one moveable contact. The vacuum interrupter further includes an operating mechanism including a clevis, the clevis to reciprocate the moveable contact. The vacuum interrupter further includes a seal between the vacuum bottle housing and the operating mechanism sealing the operating mechanism from the interior of the vacuum bottle, wherein the seal includes a first end and a second end, the first end coupled to the clevis and the second end coupled to the vacuum bottle housing. 
     In one aspect, the seal is a bellows and in another aspect, the at least one vacuum bottle is serially connected and positioned within the interior of the vacuum bottle housing. The moveable contact of each of the vacuum bottles is coupled to a spring-biased pedestal plate, and the spring biased pedestal plates are connected with a rigid member. In one aspect, the rigid member comprises a dielectric material. In another aspect, the vacuum bottle housing is pressurized. The housing can be a solid housing such as a polymer epoxy, and more particularly, a cycloaliphatic polymer epoxy. 
     According to another embodiment of the present disclosure, a vacuum interrupter for interrupting a voltage includes a vacuum bottle housing having an exterior and an interior. The vacuum bottle housing generally defines an elongated fiberglass tube. At least one vacuum bottle is positioned within the interior of the vacuum bottle housing. The at least one vacuum bottle includes axially separable contacts within it including a fixed contact and a moveable contact. An operating mechanism is coupled to the moveable contact. The operating mechanism includes a clevis configured to reciprocate the movable contact. A seal is disposed between the vacuum bottle housing and the operating mechanism sealing the operating mechanism from the interior of the vacuum bottle, the seal including a first end and a second end, the first end coupled to the clevis and the second end coupled to the vacuum bottle housing. 
     In one aspect, the at least one vacuum bottle is serially connected and positioned within the interior of the vacuum bottle housing. In another aspect, the moveable contact of each of the vacuum bottles is coupled to a spring-biased pedestal plate. In yet another aspect, the spring biased pedestal plates are connected with a rigid member. In one aspect, the rigid member comprises a dielectric material. In another aspect, the vacuum bottle housing is pressurized. The housing can be a solid housing such as a polymer epoxy, and more particularly, a cycloaliphatic polymer epoxy. 
     According to yet another embodiment of the present disclosure, a vacuum interrupter for interrupting a voltage can include a vacuum bottle housing having a pressurized interior and an exterior. At least one vacuum bottle is positioned within the interior of the vacuum bottle housing. The at least one vacuum bottle includes axially separable contacts within it, at least one of which is a moveable contact. An operating mechanism includes a clevis configured to reciprocate the moveable contact. A seal is disposed between the vacuum bottle housing and the operating mechanism sealing the operating mechanism from the interior of the vacuum bottle, the seal including a first end and a second end, the first end coupled to the clevis and the second end coupled to the vacuum bottle housing. 
     A general objective of the present application is to provide a vacuum interrupter having an improved overall construction. This objective is accomplished by providing a design for a vacuum interrupter comprised of separate housing for the vacuum bottle, sealed from the operating mechanism. 
     The foregoing and other objects and advantages of the application will appear from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration a preferred embodiment of the application. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is perspective view of an embodiment of a current interrupter according to the present disclosure; 
         FIG. 2  is a cross-sectional perspective view showing the current interrupter of  FIG. 1 ; 
         FIG. 3  is an enlarged partial cross-sectional perspective view of the foot of the current interrupter of  FIG. 2 ; 
         FIG. 4  is an enlarged partial perspective view of a vacuum bottle assembly of the current interrupter of  FIG. 1  with the vacuum bottle housing removed; 
         FIG. 5  is a perspective view of a topmost vacuum bottle of the vacuum bottle assembly of  FIG. 4  in isolation; 
         FIG. 6  is a perspective view of an intermediate vacuum bottle of the vacuum bottle assembly of  FIG. 4  in isolation; 
         FIG. 7  is top plan view of the vacuum bottle of  FIG. 5 ; 
         FIG. 8  is a cross-sectional view of the vacuum bottle of  FIG. 4  as taken along line  8 - 8  of  FIG. 7 ; 
         FIG. 9  is an enlarged partial cross-sectional view of the vacuum bottle of  FIG. 5  as taken along arc  9 - 9  of  FIG. 8 ; 
         FIG. 10  is an enlarged partial side view of vacuum bottle of  FIG. 5 ; 
         FIG. 11  is an enlarged partial cross-sectional view of the seal between the vacuum bottle housing and the operating mechanism housing of the current interrupter of  FIG. 1 ; 
         FIG. 12  is an enlarged partial perspective view of the current interrupter of  FIG. 1  showing the bi-stable operating mechanism; and 
         FIG. 13  is a side view of the bi-stable operating mechanism of the current interrupter of  FIG. 1  in isolation. 
     
    
    
     Like reference numerals will be used to refer to like parts from figure to figure in the following detailed description. 
     DETAILED DESCRIPTION 
     Before any embodiments of the application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The application is capable of other embodiments and of being practiced or of being carried out in various ways. 
     As also discussed above, in various situations it may be useful to provide a vacuum interrupter including vacuum bottles and an operating mechanism in a pressurized housing. The operating mechanism is actuated from an exterior of the housing to open and close axially separable contacts within the vacuum bottles on the interior. For example, a control arm can be pivoted to rotate a toggle within the housing that can displace a bi-stable assembly for opening and closing the vacuum bottle contact. The housing can be sealed and pressurized to protect the interior of the vacuum interrupter from moisture and contamination in general. However, it can be difficult to provide a seal between the operating mechanism on the interior of the housing and the actuator on the exterior. Various other problems may also arise depending on the operating mechanism used. 
     Use of the disclosed vacuum interrupter may address these and other issues. For example, the present disclosure provides a current interrupter including a compartmentalized housing design for sealing one or more vacuum bottles within a housing separated from an operating mechanism. The vacuum bottles can be sealed and in communication with the operating mechanism through the seal. In general, the disclosed vacuum interrupter can be used to improve the overall operation of voltage interrupting equipment with respect to providing a sealed, pressurized environment. 
     Referring to  FIG. 1 , a perspective view of a non-limiting example of a vacuum interrupter  10  for interrupting a voltage is shown. The current interrupter  10  has a generally elongate, cylindrical construction comprising a centrally positioned vacuum bottle housing  12 . The vacuum bottle housing  12  can be a sealed vessel formed from an insulating material such as a fiberglass tube. An interior  14  of the vacuum bottle housing  12  can accommodate one or more vacuum bottles  50  (see, for example,  FIG. 2 ) that are operable to interrupt a voltage. One end of the vacuum bottle housing  12  can be coupled to an operating mechanism housing  15  that contains a bi-stable operating mechanism  16  for operating the one or more vacuum bottles  50  within the vacuum bottle housing  12 . The bi-stable operating mechanism  16  can be manipulated with an actuator  17  that can include a rotatably mounted control arm  18 . A spring operated reset mechanism  19  can be in communication with the actuator  17  to bias the vacuum interrupter  10 , and in particular, the one or more vacuum bottles  50  towards a closed or uninterrupted position. 
     Whereas a first end of the vacuum bottle housing  12  can be coupled to the operating mechanism housing  15 , a second, opposing end can be coupled to a foot  21  for mounting the vacuum interrupter  10 . The lower end  22  of the foot  20  can be secured by bolts passing through holes  24  in order to mount the vacuum interrupter  10  to a structure such as an air break switch structure insulator (not shown) or another component of a power transmission structure. 
     The interior  14  of the vacuum bottle housing  12  as illustrated in  FIG. 2  can include three vacuum bottles  50 , which can be connected in series. While three vacuum bottles  50  are shown in the illustrated embodiment, a vacuum interrupter  10  can include one or more vacuum bottles  50 , such as between one and eight vacuum bottles. In one example, a current interrupter  10  can include a single vacuum bottle  50  to accommodate a 27 kV system, whereas in another example, eight vacuum bottles  50  may be serially connected within a single vacuum bottle housing  12  to accommodate a 230 kV system. 
     Each of the vacuum bottles  50  can have an outer shell  52  surrounding axially separable contacts including a fixed contact  60  and a moveable contact  62 . The moveable contacts  60  can be coupled for concurrent operation with bi-stable operating mechanism  16 . In the illustrated embodiment, a moveable contact  60  of the uppermost vacuum bottle  50  (i.e., the vacuum bottle  50  closest to the operating mechanism housing  15 ) is coupled to the bi-stable operating mechanism  16 . Aspects of the bi-stable operating mechanism  16  and vacuum bottles  50  are described in greater detail herein. 
     With reference to  FIG. 3 , the connection of the vacuum bottle housing  12  with foot  20  is schematically illustrated. An upper end  26  of the foot  20  can have a disc-shaped construction with holes  28  positioned at regular intervals about a circumference of the disc-shaped upper end  26 . The upper end  26  can further include a circumferential groove  30  sized to receive an O-ring or other ring-shaped seal  32 . In order to provide a sealed interface between the vacuum bottle housing  12  and the foot  20 , a first end  34  of the vacuum bottle housing  12  can be received in a cylindrical recess defined by upright inner and outer walls  36  and  38  and lower end face  40  of a collar  42 . An exterior surface of the lower end face  40  contacts seal  32  to form an interface with the upper end  26  of the foot  20 . In some embodiments, the interface between the collar  42  and the foot  20  can provide a fluid-tight seal to maintain a pressurized atmosphere within the bottle and prevent water, other fluids, gasses and contaminants in general from penetrating the interior  14  of the vacuum bottle housing  12 . 
     As shown in  FIGS. 1-3 , a number of ribs  44  can be positioned in spaced relation along an axial direction of an exterior surface of the outer wall  38  of the collar  42 . Threaded passages  46  can be formed in ribs  44  and aligned with holes  24  in upper end  26  to receive fasteners such as threaded bolts  48  in order to couple collar  42  to foot  20 . Alternatively, or additionally, bolts, rivets, adhesives or other suitable fasteners or joining techniques such as welding or soldering can be used. In other embodiments, collar  42  and foot  20  can be formed as a unitary cast structure. 
     Turning to  FIG. 4 , an enlarged view of vacuum bottles  50  is shown with the vacuum bottle housing  12  removed. Each vacuum bottle  50  can comprise a hollow cylindrical structure capable of maintaining a vacuum seal. As shown in  FIGS. 4-10 , an outer shell  52  of the vacuum bottle  50  can have a cylindrically shaped side wall  54  coupled to opposed upper and lower end faces  56  and  58 . Within the outer shell  52 , the lower fixed contact  60  and upper moveable contact  62  can be positioned coaxially on a central axis of the outer shell  52 . Each of the fixed and moveable contacts  60  and  62  can include facing contact plates  64 ,  66  disposed on ends of rods  68 ,  70 , respectively. The moveable contact  62  is slidably displaceable with rod  70  extending through a bushing  72  positioned centrally in the upper end face  56  of the outer shell  52 . In some embodiments, the moveable contact  62  is displaceable with a bellows type seal that is operative to maintain a vacuum within the vacuum bottle and a positive pressure outside of the vacuum bottle  50  but within the interior  14  of the vacuum bottle housing  12 . However, any suitable mechanism can be used to maintain a vacuum seal within a vacuum bottle  50 . 
     For vacuum interrupters  10  with two or more vacuum bottles  50  as in the illustrated embodiment, one or more of the vacuum bottles  50  can be provided with lower and upper mounting plates  74  and  76 , respectively, including three equiangularly spaced arms  78 . The lower mounting plate  74  can be positioned adjacent to the lower end face  58  of a first vacuum bottle  50  and an upper mounting plate  76  can be positioned adjacent to the upper end face  56  of an adjacent (lower) vacuum bottle  50 . In order to mount the adjacent vacuum bottles  50  to one another, the outer extremities  78  of the lower and upper mounting plates  74 ,  76  can be connected by upright posts  80 . 
     For each vacuum bottle  50 , rod  70  of moveable contact  62  can pass through an upper mounting plate  76  to couple to a spring biased pedestal plate  82  positioned above upper mounting plate  76 . Rod  70  can couple to the pedestal plate  82  with a nut  84  on its upper end with an enlarged head forming a shoulder above the upper surface of the pedestal plate  81 . In one aspect, when the pedestal plate  82  is moved upwardly and engages the thumb nut shoulder, it can raise the moveable contact  62 . A cushion spring  86  surrounding rod  70  can be positioned between the bottom of pedestal plate  82  a washer  88  mounting a conductive braid  89 . In one aspect, when the pedestal plate  82  is lowered, the cushion spring can be compressed between the pedestal plate  82  and the washer  88  and push the moveable contact  62  downwardly into contact with the fixed contact  60 , thereby ensuring conductive engagement. Pedestal plate  82  can be biased away from upper mounting plate  76  by symmetrically and triangularly arranged return springs  90 , which can, in turn, bias moveable contact  62  upwardly and away from fixed contact  60 . 
     In embodiments including two or more serially connected vacuum bottles  50 , each pedestal plate  82  can be connected with vertical rigid members  92  of a dielectric or insulating material such as fiberglass. The rigid members  92  can move each of the pedestal plates  82 , and therefore, the moveable contacts  62  in a concurrent manner to achieve serial operation of the connected vacuum bottles. In other embodiments, lower and upper mounting plates  74 ,  76  can be connected with a capacitor  94  to provide a voltage grading effect across each vacuum bottle  50 . In one aspect, the capacitor  94  can be selected to correspond to the voltage of the circuit to be interrupted. 
     With respect to  FIG. 5  an uppermost vacuum bottle  50  can include one or more stops  96  positioned on top of pedestal plate  82 . In one aspect, the stops  96 , which can be aluminum, can be used to space the pedestal plate  82  away from a seal or interface between the vacuum bottle housing  12  and the operating mechanism housing  15 . Turning to  FIG. 6 , vacuum bottles  50  can also include studs  98  that project radially outward from posts  78 . Studs  98  can abut or couple to the vacuum bottle housing  12 , for example, to eliminate movement of the vacuum bottles and maintain their adjustment during shipping and installation of the device. In one aspect, studs  98  can comprise rubber or another insulating material. 
     As with the first end  34  of the vacuum bottle housing  12 , a second end  100  of the vacuum bottle housing  12  can be received in an upper collar  102  as shown in  FIG. 11 . The upper collar  102  can include a cylindrical recess defined by upright inner and outer walls  104  and  106  and upper end face  108 . The upper end face forms a sealed interface with a bi-stable plate  110  positioned generally between the vacuum bottle housing  12  and the operating mechanism housing  15 . The bi-stable plate  110  can serve to seal the end of the vacuum bottle housing, and support the bi-stable operating mechanism  16 . In one aspect, a channel  112  in the bi-stable plate  110  can accommodate an O-ring  114  to provide a sealed interface. However, as described previously, other methods for providing a seal can be used. 
     In addition (or alternatively), the bi-stable plate  110  can form a sealed interface with a bellows  116  disposed on the upper face of the bi-stable plate  110 . The bellows  116  can comprise a conventional cylindrical steel accordion-like structure, which maintains its integrity while shortening and lengthening. In particular, bellows  116  can have a cylindrical construction with a circumferentially ribbed side wall having a serpentine cross-section as shown in  FIG. 11 . The ribbed side-wall can enable the bellows  116  to be alternately compressed and expanded by operation of the bi-stable operating mechanism  16  while maintaining the integrity of the seal. One method sealing the bellows with the bi-stable plate  110  can include mounting a circular gasket  118  at a base of the bellows  116 . The circular gasket  118  is generally ring-shaped with an inner diameter sized to receive and seal with the lower end of the bellows  116 . The gasket  118  extends radially outward from the lower end of the bellows  116  with an outer diameter of the gasket  118  being greater than an outer diameter of the bellows  116 . In turn, a cylindrical bellows housing  120  can be fitted over the bellows  116  such that an externally flanged lower end  122  of the bellows housing  120  contacts a periphery of the gasket  118 . An outer edge of the flanged lower end  122  can overlap and extend outward from the periphery of the gasket  118 . In some embodiments, circumferentially spaced holes  124  can be provided in the flanged lower end  122 . Fasteners  126  such as screws can pass through holes  124  into the upper face of the bi-stable plate  110  to mount the bellows  116  to the bi-stable plate  110 . 
     A clevis  128  extends axially through the center of bellows  116  with a head  130  of the clevis  128  forming a seal with the upper end of the bellows  116 . In one aspect, the head  130  can be welded to the bellows  116  to further provide a seal between the vacuum bottle housing  12  and the operating mechanism housing  15 . The clevis  128  can pass through the bellows  116  and through a bushing  132  with an externally flanged lower end supported in a recess of on the lower end of the bi-stable plate  110 . The lower end of the clevis can be coupled to a cylindrical member  134 , which can contact the upper face of the pedestal plate  82  of the topmost vacuum bottle  50 . The cylindrical member  134  surrounds the nut  84  connected to rod  70  of the moveable contact  62  of the topmost vacuum bottle  50 . As a result, a linear, downward displacement of the clevis  128  and the cylindrical member results in the opening and the closing of the fixed and moveable contacts  60 ,  62 . 
     Turning to  FIGS. 12 and 13 , an embodiment of a bi-stable operating mechanism  16  is shown. A pair of opposed bi-stable link adjustment bolts  136  pass through openings  138  in the operating mechanism housing  15 . The bi-stable link adjustment bolts  136  are oriented in a transverse direction (i.e., orthogonal) relative to the central axis of the vacuum interrupter  10 . A pin  140  extends through the operating mechanism housing  15  at a right angle relative to the opposed bi-stable link adjustment bolts  136 . The pin  140  is spaced laterally apart from bi-stable link adjustment bolts  136  towards an upper end of the operating mechanism housing  15 . An end of the pin  140  passes through a connector  142  of the actuator  17  located external to the cylindrical housing  64 . The connector  142  is configured to receive and fasted to one end of the control arm  18  such that the control arm  18  is rotatable about an axis of the pin  140 . In the example embodiment shown in  FIGS. 12 and 13 , the connector  142  includes a pair of clamps for retaining the operating arm  18 . 
     The head  130  of the clevis  128  couples the moveable contact  62  of the topmost vacuum bottle  50  to bi-stable operating mechanism  16 . The bi-stable mechanism  16  generally inhabits a vertical plane parallel to an axis of the vacuum interrupter  10  and comprises a pair of pivotally connected links  144  and a toggle  146 . The links  144  are independently pivotable about an axis of the pin  140 , while the toggle  146  is pivotable with the pin  140 . A pair of bumpers  148  is coupled to the toggle  146  such that rotation of the toggle  146  causes the bumpers  148  to impinge upon the links  144  in order to displace the links  144 . The extent to which the links  144  can move is limited by adjustment of the opposed bi-stable link adjustment bolts  136  which are also generally oriented in the plane of the bi-stable operating mechanism  16 . Displacement of the links  144  results in a displacement of the clevis  128  along the axis of the vacuum interrupter  10 , and therefore a displacement of the moveable contact  62  of the topmost vacuum bottle  50 . 
     In one example method of operation, the vacuum interrupter  10  starts in a closed position. In the closed position, the bi-stable operating mechanism  16  is in a first position such that the moveable contacts  62  and fixed contacts  60  are made to touch. In this position the cushion spring  86  and return springs  90  are compressed by the pedestal plate  82 . The pedestal plate  82  position is held by the links  144  pushing the clevis  128  against the cylindrical member  134  on the upper face of the pedestal plate  82 . Contact pressure is applied to the bellows  116  and clevis  128  by the cushion spring  86  to maintain contact. 
     In the closed position, a current can travels through the vacuum interrupter  10 , in the following manner. Current travels through the foot  20 , to collar  42  and into the fixed contact  60  of the lowermost vacuum bottle  50 . The current then flows from the fixed contact  60  to the moveable contact  62  and into one of the upright posts  80  through conductive braid  89  to the lower mounting plate  74  of the next adjacent vacuum bottle  50 . The current can flow from the lower mounting plate  74  to the fixed contact  60  of the respective vacuum bottle  50  and so forth through each of the connected vacuum bottles  50 . From the conductive braid  89  of the topmost vacuum bottle  50 , the current can travel through the pin  140  via a second flexible conductive braid, and into the conductive control arm  18 . 
     The vacuum interrupter  10  provides arc quenching when transitioned into the open position. Opening occurs when the control arm  18  is pivoted on the axis of the pin  140 , thereby rotating the toggle  146  and bumpers  148 . As the bi-stable links  144  are forced over center by the bumpers  148 , the clevis  128  releases the pedestal plate  82  allowing the return springs  90  to push upward. The pedestal plate  82  pushes the nut  84 , which is coupled to the clevis  128  and bellows  116 , upward. This action pulls the moveable contacts  62  upward to the open position. 
     As shown at least in  FIG. 8 , the difference in the two positions of the bi-stable operating mechanism  16  is a ¼ inch displacement along the central axis of the vacuum interrupter  10 . Within the reset mechanism  19 , a compression spring  150  biases the bi-stable operating mechanism  16  towards a closed position of the vacuum interrupter  10 . The bi-stable operating mechanism  16  can be used as it provides for free and rapid movement of the pedestal plates and the vacuum bottle contacts, as is required for quick separation of the contacts. 
     The present vacuum interrupter assembly improves upon prior art vacuum interrupter by providing a seal between the vacuum bottle housing and the operating mechanism housing. In one aspect, the bi-stable operating mechanism can require both rotational and linear movements. For example, the control arm is rotatable to displace the bi-stable links from a first position to a second position. In turn, the bi-stable links can effect a linear displacement of the clevis and the moveable contacts. By providing the seal between the vacuum bottle housing and the operating mechanism housing, it can be only necessary to provide a seal for a linear movement and not also a rotational movement. In one aspect, a bellows can provide an expandable seal to enable to the linear movement. However, other seals can be used in place of a bellows to accommodate a sealed, linear displacement. 
     According to another aspect of the present disclosure, a vacuum interrupter includes a pressurized vacuum bottle housing. However, it is possible that the current interrupter of this disclosure can include a plurality of vacuum bottles contained in various housings. For example, the vacuum bottles may be housed in pressurized fiberglass tubes, or a solid insulating material such as an epoxy or resin, and in particular, a cycloaliphatic epoxy. 
     For example, the general orientation of the vacuum interrupter, and components thereof, can differ from that depicted in the figures. In particular, the figures illustrate a generally vertically extending vacuum interrupter. However, the vacuum interrupter can instead be at an arbitrary angle to the horizon. Therefore, any words of orientation, such as various forms of “up”, “down”, “top”, “bottom,” “above,” and “below”, used herein are for the purpose of describing particular embodiments only and are not intended to be limiting of the disclosure. 
     While there has been shown and described what are at present considered the preferred embodiment of the application, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the scope of the application.