Overlap protective shutter device for electrical equipment

A protective shutter device for exposing and preventing access to electrical contacts of a switchgear. The device includes a linkage assembly coupled to the housing, the linkage assembly including a first and a second drive arm. A guide assembly is coupled to the housing, and includes a first end, a second end, and a body connecting the ends. The device further includes a first shutter coupled to the first drive arm and the body of the guide assembly. The first shutter selectively moves along the body. A second shutter is coupled to the second drive arm and the guide assembly body, the second shutter including a lower and an upper plate. The lower plate is coupled to the upper plate, wherein the plates selectively move along the body to a first position to expose the electrical contacts, and to a second position to prevent access to the electrical contacts.

BACKGROUND OF THE INVENTION

The embodiments described herein relate generally to a shutter device for a switchgear housing, and more particularly, to methods and devices used to prevent access to voltage line terminals within the switchgear housing by an overlap protective shutter device.

In known construction of a switchgear housing of the draw-out type, the movable electrical contacts of a circuit breaker are mounted within insulating bushings. The insulating bushings extend into insulating tubes which are mounted in terminal apertures of the associated switchgear housing to engage fixed electrical contacts disposed in the insulating tubes. In order to protect operating and maintenance personnel who enter the switchgear housing, known shutters are used to close the openings to the insulating tubes when the circuit breaker is removed from the normal operating position.

Conventional shutters are activated by the circuit breaker moving into and out of the switchgear housing. As the circuit breaker moves into the housing, known shutters move to a position either above or below the fixed electrical contacts to expose the fixed electrical contacts. As the circuit breaker moves out of the housing to disconnect from the switchgear, known shutters move to prevent access to the electrical contacts of switchgear. Conventional shutters, however, are not sized for multi-tiered, compact switchgear configurations.

BRIEF DESCRIPTION OF THE INVENTION

In one aspect, a protective shutter device for exposing and preventing access to electrical contacts of a switchgear is provided. The device includes a linkage assembly coupled to the housing, wherein the linkage assembly includes a first drive arm and a second drive arm. A guide assembly is coupled to the housing, wherein the guide assembly includes a first end, a second end and a guide body connecting the first end and the second end. The device further includes a first shutter coupled to the first drive arm of the linkage assembly and the guide body of the guide assembly. The first shutter is configured to selectively move along the guide body. A second shutter is coupled to the second drive arm of the linkage assembly and the guide body of the guide assembly, wherein the second shutter includes a lower plate and an upper plate. The lower plate is coupled to the upper plate, wherein the lower plate and the upper plate are configured to selectively move along the guide body to a first position which is configured to expose the electrical contacts and to a second position which is configured to prevent access to the electrical contacts.

In another aspect, a switchgear device for exposing and preventing access to electrical contacts of a switchgear is provided. The device includes a housing having a top, a bottom, a sidewall and a back wall connecting together the top and the bottom. The back wall includes a plurality of terminal apertures defined there through. A linkage assembly is configured to couple to the housing, wherein the linkage assembly includes a first drive arm and a second drive arm. A guide assembly is coupled to the housing, wherein the guide assembly includes a first end, a second end and a guide body connecting the first end and the second end. The device further includes a first shutter coupled to the first drive arm of the linkage assembly and the guide body of the guide assembly. The first shutter is configured to selectively move along the guide body. A second shutter is coupled to the second drive arm of the linkage assembly and the guide body of the guide assembly, wherein the second shutter includes a lower plate and an upper plate. The lower plate is coupled to the upper plate, wherein the lower plate and the upper plate are configured to selectively move along the guide body to a first position which is configured to expose the electrical contacts and to a second position which is configured to prevent access to the electrical contacts.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1illustrates a front view of a switchgear10and an exemplary shutter assembly12and including shutter assembly12orientated in a first position14. Shutter assembly12is shown in first position14which represents an operational state of switchgear10.FIG. 2illustrates another front view of switchgear10and shutter assembly12coupled to switchgear10and including shutter assembly12orientated in a second position16. Shutter assembly12is shown in a second position16which represents a non-operational state of switchgear10.

Switchgear10includes a housing18having a top20, a bottom22, and opposing sidewalls24connecting top20and bottom22. Housing18further includes a back wall26coupled to top20, bottom22, and sidewalls24. Housing18defines a cavity28therein. Back wall26includes an inner side30which is orientated to face cavity28.

Each sidewall24includes a top end32, a bottom end34, and a side36connecting top end32and bottom end34. The height of sidewall24, as measured between top end32and bottom end34, is less than or about equal to 950 mm (about 37 in.). In an embodiment, the height includes a range from about 250 mm (about 10 in.) to about 750 mm (about 30 in.) The width of top20and bottom22of housing18, as measured between sidewalls24, is less than or about equal to 950 mm. In an embodiment, the width of top20and bottom22of housing18includes a range from about 250 mm to about 750 mm. Sizing of top20, bottom22, and sidewalls24for housing18facilitates stacking a plurality of housings18in a space substantially similar to a space used by single, known switchgear housing (not shown). In the exemplary embodiment, top20, bottom22, and sidewalls24are sized and shaped to form a stacked configuration38of a pair of housings18within a space used by a single, conventional switchgear (not shown).

Back wall26includes at least one terminal aperture40defined through inner side30. In the exemplary embodiment, back wall26includes a pair of rows R1, R2of substantially horizontal terminal apertures40with each row R1, R2having a plurality of terminal apertures40. Rows R1, R2of terminal apertures40are spaced from one another in a common vertical plane with terminal apertures40being laterally spaced from one another. Any number of rows and terminal apertures40can be used for operation of switchgear10.

FIG. 3illustrates a side elevational view of a circuit breaker42that is positioned next to switchgear10(shown inFIG. 1). Circuit breaker42includes a housing44having a front side46, a back side48, and sidewalls50coupling front side46and back side48. Sidewalls50include wheels52which are configured to move circuit breaker42in and out of cavity28when acted upon by a force (not shown). Circuit breaker42includes at least a pair of substantially horizontal insulating bushings54, with bushings54of each pair being spaced from one another in a common vertical plane and with the different pairs of bushings54being laterally spaced from one another. An electrical contact56is disposed within each bushing54. Bushings54are sized and shaped to facilitate coupling electrical contacts56of circuit breaker42to fixed electrical contacts58of switchgear10.

Each terminal aperture40is sized, shaped and orientated to facilitate supporting an insulating tube60. Fixed electrical contact58is disposed inside each insulating tube60mounted within respective terminal apertures40. Each of the fixed electrical contacts58is electrically connected to a power conductor62which is electrically insulated by insulating tube60.

FIG. 4illustrates a perspective view of switchgear10and including shutter assembly12shown in second position16.FIG. 5illustrates another perspective view of the switchgear10and shutter assembly12shown in first position14. In an embodiment, first position14is configured to expose at least one terminal aperture40to allow access to exposed terminal aperture40. Further, in an embodiment, second position16is configured to cover at least one terminal aperture40to prevent access to covered terminal aperture40. In first position14as described herein, shutter assembly12is configured to allow coupling of circuit breaker42to switchgear10for an operative state of switchgear10. In second position16as described herein, shutter assembly12is configured to prevent coupling of circuit breaker42to switchgear10.

Switchgear10further includes a track assembly64coupled to each sidewall24in a location proximate bottom22of housing18. Track assembly64includes tracks or rails66located along each sidewall24. Track assembly64couples to wheels52of circuit breaker42to facilitate reciprocally moving circuit breaker42in and out of housing cavity28.

Switchgear10also includes a linkage assembly68coupled to each sidewall24. Linkage assembly68is configured to facilitate operating shutter assembly12during the operational state of switchgear10. Linkage assembly68includes a first bracket assembly70, a second bracket assembly72, an actuator member74and a bias member76. Actuator member74couples to first bracket assembly70and second bracket assembly72. Actuator member74is configured to convert linear motion of circuit breaker42moving along rails66to a rotational moment imparted to first bracket assembly70and second bracket assembly72as described herein. Bias member76is configured to move actuator member74when circuit breaker42removes force applied to actuator member74. Any linkage assembly may be used to convert linear motion to rotational motion as described herein.

First bracket assembly70includes a linkage arm78coupled to actuator member74. First bracket assembly70further includes a pivot arm80coupled to linkage arm78. A first drive arm84pivotally couples to pivot arm80about pivot pin82. First drive arm84includes an end86having a drive pin88.

Second bracket assembly72includes a linkage arm90coupled to actuator member74. Second bracket assembly72further includes a pivot arm92coupled to linkage arm90. A second drive arm96pivotally couples to pivot arm92about pivot pin94. Second drive arm96includes an end97having a pin aperture98.

Switchgear10further includes a guide assembly100coupled to back wall26. Guide assembly100includes a guide member102having a first end104, a second end106, and guide body108connecting first end104and second end106. A plurality of supports110is configured to mount guide member102to back wall26. Each support110includes a support aperture112which is sized and shaped to surround a portion of guide body108. In an exemplary embodiment, supports110mount guide member102on back wall26substantially adjacent housing sidewall24to facilitate locating first end104proximate housing bottom22and second end106proximate housing top20. Supports110can include any configuration to facilitate mounting guide body108to back wall26.

Shutter assembly12is configured to couple with linkage assembly68and with guide assembly100. Shutter assembly12is configured to reciprocally move between first position14and second position16. In first position14, shutter assembly12facilitates coupling circuit breaker42(FIG. 3) to electrical contacts58(FIG. 3) of switchgear10. While in second position16, shutter assembly12prevents access to electrical contacts58of switchgear10.

Shutter assembly12includes a first shutter116and a second shutter118. First shutter116is configured to prevent access to at least row R1of terminal apertures40in second position16and to allow access to at least row R1of terminal apertures40in first position14. First shutter116includes a plate120having a front side122facing cavity28of housing18and having a rear side (not shown) facing back wall26. Plate120has a size and shape to substantially prevent access to at least electrical terminal apertures40of row R1of back wall26.

FIG. 6illustrates a front partial view of first shutter116of shutter assembly12shown inFIGS. 4 and 5. First shutter116further includes a flange126coupled to front side122and extending outward from front side122toward cavity28of housing18. Flange126includes a first end128, a second end130, and sidewall132connecting first end128and second end130. First end128and second end130include a guide aperture134defined therethrough. Guide aperture134is sized and shaped to slidably surround portions114of guide body108of guide assembly100. Flange sidewalls132further include a pin aperture136defined therethrough. Pin aperture136is sized and shaped to accept and couple to drive pin88of first drive arm84for first bracket assembly70.

In second position16as described herein, linkage assembly68is configured to move first shutter116to cover to terminal apertures40positioned in row R1. In second position16, first shutter116is configured to facilitate preventing access to terminal apertures40of row R1. In first position14as described herein, linkage assembly68is configured to move first shutter116away from terminal apertures40of row R1to expose terminal apertures40. In first position14, first shutter116is configured to facilitate allowing access to terminal apertures40of row R1.

FIG. 7is a front view of a second shutter118of shutter assembly12shown inFIGS. 4 and 5. Second shutter118couples to linkage assembly68(shown inFIG. 4) and to guide assembly100. Second shutter118is configured to prevent access to at least row R2of terminal apertures40in second position16and to allow access to row R2of terminal apertures40in first position14. Second shutter118includes a lower plate138and an upper plate140. Lower plate138is configured to reciprocally overlap and move upper plate140as described herein.

Upper plate140has a front side141facing cavity28of housing18and a rear side (not shown) facing back wall26. Upper plate140includes an upper flange142coupled to front side141and extending outward toward housing cavity28. Upper flange142includes a first end144, a second end146, and a sidewall148connecting first end144and second end146. First end144and second end146include guide aperture134defined therethrough. Guide aperture134is sized and shaped to slidably surround portions114of guide body108.

Sidewall148of upper flange142includes a slot150longitudinally located along axis152of flange142. Slot150is located between first end144and second end146. Upper flange142further includes a support arm154extending outward from and toward sidewall24of housing18. In second position16, support arm154is configured to contact and rest upon support110coupled to sidewall24. Support110, in second position16, is configured to hold and suspend upper plate140along guide body108. Upper plate140has a size and shape to substantially cover at least half of terminal apertures40of row R2for back wall26. In an embodiment, upper plate140is sized and shaped to cover at least upper portions of terminal apertures40of row R2. In the exemplary embodiment, upper plate142is sized and shaped to prevent access to at least upper portions of terminal apertures40of row R2.

Lower plate138has a front side156facing housing cavity18and a rear side (not shown) facing back wall26. Lower plate138is configured to overlap upper plate140and move upper plate140in first position14. Lower plate138includes a lower flange162coupled to front side156and extending outward toward housing cavity28. Lower flange162includes a first end164, a second end166, and a sidewall168connecting first end164and second end166. First end164and second end166include a guide aperture134defined therethrough. Guide aperture134is sized and shaped to slidably surround portions114of guide body108.

Sidewall168of lower flange162includes slot pin170extending outward from sidewall168and toward sidewall24of housing18. A fastener (not shown) secures slot pin170to lower flange162. In an exemplary embodiment, fastener includes a clip. Any fastener to secure slot pin170to flange162can be used as described herein. Slot pin170couples to second drive arm96(shown inFIG. 4) of second bracket assembly72. Slot pin170is sized and shaped to facilitate extending through slot150of upper plate140and rests upon upper flange142of upper plate140in second position16. Lower plate138has a size and shape to substantially cover at least half of electrical terminal apertures40of row R2for back wall26. In an exemplary embodiment, lower plate138is sized and shaped to cover at least lower portions of terminal apertures40of row R2. In the exemplary embodiment, lower plate138is sized and shaped to prevent access to at least lower portions of terminal apertures40of row R2.

In second position16as described herein, linkage assembly68is configured to move second shutter118to cover terminal apertures40positioned in row R2. In second position16, second shutter118is configured to facilitate preventing access to terminal apertures40of row R2. In first position14as described herein, linkage assembly68is configured to move second shutter118away from terminal apertures40of row R2to expose terminal apertures40. In first position14, second shutter118is configured to facilitate allowing access to terminal apertures40of row R2. In the exemplary embodiment, lower plate138is configured to substantially overlap upper plate140in first position14.

Since lower plate138is sized, shaped, and orientated to facilitate overlapping upper plate140and moving along guide body108with upper plate140, less space is needed above terminal apertures40of row R2to locate lower plate138and upper plate140in first position14. In the exemplary embodiment, the overlap configuration of lower plate138and upper plate140reduces about one half the space of back wall26above terminal apertures40of row R2as compared to the space of back wall26that is below terminal apertures40of row R1. Accordingly, the size of housing18is reduced to facilitate the compact, multi-tiered/stacked switchgear configuration38(shown inFIG. 1).

In an exemplary operation of switchgear10, circuit breaker42is moved into housing cavity28. Wheels52of circuit breaker42facilitate moving circuit breaker42on rails66to facilitate front side46of circuit breaker42contacting actuator member74of linkage assembly68. Actuator member74is configured to facilitate moving linkage arm78of first bracket assembly70. Linkage arm78of first bracket assembly70in response to movement rotates first drive arm84about pivot pin82. In the exemplary embodiment, linkage arm78rotates downward to move first drive arm84downward.

First drive arm84, which is coupled to first shutter plate120via drive pin88, is configured to slide first shutter plate120downward along guide body108and away from terminal apertures40of row R1. Drive pin88moves first shutter plate120proximate housing bottom22to expose terminal apertures40of row R1in first position14. The sizes of first drive arm84and first shutter plate120locate the first shutter plate120between bottom22of housing18and terminal apertures40of row R1. In first position14, electrical contacts56of circuit breaker42are exposed to electrical contacts58within insulating tubes60. Circuit breaker42continues to move toward electrical contacts58of switchgear10to couple to electrical contacts58during the operational state of switchgear10.

While circuit breaker42moves into housing18, actuator arm74is configured to facilitate moving linkage arm90of second bracket assembly72. Linkage arm90, in response to movement, rotates second drive arm96about pivot pin94. In the exemplary embodiment, linkage arm90rotates upward to move second drive arm96upward. Second drive arm96, which is coupled to second shutter118at slot pin170, slides lower plate138upward along guide body108and away from terminal apertures40of row R2.

Second drive arm96further moves slot pin170within slot150of upper flange142of upper plate140. As slot pin170moves within slot150, lower plate138is configured to move upward and substantially overlap upper plate140. Additionally, as lower plate138substantially overlaps upper plate140, lower flange162on the lower plate138contacts flange upper142of upper plate140. Second drive arm96continues to move lower plate138to facilitate lifting upper flange142of upper plate140off of support110. Second drive arm96moves lower plate138to at least partially overlap upper plate140and move lower plate138and upper plate140beyond terminal apertures40.

Second drive arm96is sized to position upper plate140and lower plate138in the overlap position above terminal apertures40and below top20of housing18to expose terminal apertures40. In the first position14, upper electrical contacts56of circuit breaker42are exposed to electrical contacts58within insulating tubes60. Circuit breaker42continues to move toward electrical contacts58of switchgear10to couple to electrical contacts58during the operational state of switchgear10.

In an exemplary inoperative state of switchgear10, circuit breaker42is disconnected and moved away from electrical contacts58along rails66to disconnect electrical contacts56of circuit breaker42from electrical contacts58of switchgear10. When circuit breaker42moves away from back wall26, circuit breaker42removes pressure applied to actuator arm74of linkage assembly68. Bias member76is configured to pressure actuator arm74to facilitate moving actuator arm74away from back wall26to facilitate reverse operation of linkage assembly68. Actuator arm74rotates linkage arm78of first bracket assembly70upward around pivot pin82which moves first drive arm84upward. Plate120of first shutter116is configured to slide upward along guide body108and in front of terminal apertures40of row R1. In the second position16, plate120facilitates preventing access to electrical contacts58to facilitate minimizing or eliminating exposure to electrical contacts58and/or arcing from electrical contacts58of switchgear10.

When circuit breaker42is disconnected and moved away from electrical contacts58, actuator arm74further rotates linkage arm90of second bracket assembly72downward around pivot pin94which moves second drive arm96downward. Second drive arm96through slot pin170slides lower plate138downward along guide body108. Slot pin170moves downward within slot150of upper plate140. Since upper flange142of upper plate140rests on lower flange162of lower plate138in the first position14, upper plate140moves downward with lower plate138until upper flange142of upper plate140contacts support110coupled to sidewall24. Support110contacts support arm154to stop and support upper plate140in a position to at least partially cover terminal apertures40of row R2. In an exemplary embodiment, upper plate140substantially covers at least upper portions of terminal apertures40of row R2. In the exemplary embodiment, upper plate140is configured to prevent access to at least terminal apertures40of row R2.

While support110suspends upper plate140to at least partially cover terminal apertures40of row R1, second drive arm96continues to rotate to lower plate138through coupling with slot pin170. Slot pin170moves downward within slot150of upper flange142of upper plate140to facilitate moving lower plate138in position to at least partially cover terminal apertures40of row R2. Slot pin170rests on bottom of slot150to suspend lower plate138in the second position16. In an embodiment, lower plate138substantially covers lowers portions of terminal apertures40of row R2. In the exemplary embodiment, lower plate138is configured to prevent access to at least terminal apertures40of row R2.

FIG. 8illustrates a schematic view of another exemplary shutter assembly172shown in first position14.FIG. 9illustrates another schematic view of shutter assembly172shown in second position16. Shutter assembly172includes a first shutter174and a second shutter176. First shutter174includes a lower plate178and an upper plate180. Second shutter176includes a lower plate182and an upper plate184.

First drive arm84of first bracket assembly70(shown inFIG. 2) is configured to couple to lower plate178and lower plate182. Second drive arm96of second bracket assembly72(shown inFIG. 2) is configured to couple to upper plate180and upper plate184. During the operational state of switchgear10first drive arm84moves lower plates178,180into first position14and second drive arm96moves upper plates180,184into first position14. In first position14, lower plate182of second shutter176is configured to overlap upper plate180of first shutter174. The traveling distances for first shutter174and second shutter176to first position14is reduced by the overlapping plates180,182to facilitate reducing the size of the switchgear housing (not shown).

FIG. 10is an exemplary flowchart1000illustrating a method1010of controlling access to a switchgear, for example switchgear10(shown inFIG. 1) during an operational state and a non-operational state. Method1010includes receiving1012a circuit breaker, for example circuit breaker42(shown inFIG. 3) and moving1014a linkage assembly, for example linkage assembly68(shown inFIG. 4). Linkage assembly moves1016a shutter assembly, such as shutter assembly12(shown inFIG. 4) to a first position, for example first position14(shown inFIG. 6). In first position14, electrical contacts of switchgear are exposed for coupling to circuit breaker. In the exemplary embodiment, moving shutter assembly includes moving1018a lower plate, for example lower plate138(shown inFIG. 5), to overlap and to contact an upper plate, for example upper plate140(shown inFIG. 5). Method110includes moving lower plate/upper plate to an overlapped position to expose electrical contacts of switchgear. Circuit breaker is coupled1020to switchgear during the operational state of switchgear.

Method110further includes de-coupling1022circuit breaker from electrical contacts and removing circuit breaker from switchgear. Linkage assembly, in response to the removal of the circuit breaker, moves shutter assembly to the second position. In the exemplary embodiment, method includes moving1024lower plate/upper plate from the overlapped position to the second position, such as second position16(shown inFIG. 4) to cover electrical contacts of switchgear, such as switchgear10. In the second position, shutter assembly prevents access to electrical contacts of switchgear.

The embodiments described herein provide a protective device for a switchgear. The disclosed dimensions include all sub ranges therebetween. The dimensions facilitate reducing the size of the housing for switchgear. The protective device can be used for new manufacture of switchgears or for integration with existing switchgears. In one embodiment, the protective device includes an overlapping shutter configured to move along the switchgear. The overlapping shutter reciprocates between an first position to facilitate exposing electrical contacts of the switchgear and a second position to facilitate preventing access to the electrical contacts. The overlapping shutter provides more efficient and effective shutter designs to prevent access to any live parts to facilitate minimizing or eliminating arcing. Further, the overlapping shutter reduces the size of the switchgear housing.

A technical effect of the system described herein is that the overlapping shutter reciprocates between an first position to facilitate exposing electrical contacts of the switchgear and a second position to facilitate preventing access to the electrical contacts. Another technical effect of the overlapping shutter provides more shutter designs to minimize or prevent access to live parts to facilitate minimizing or eliminating arcing while reducing the size of the switchgear housing.

Exemplary embodiments of the protective device and methods of preventing access to the switchgear are described above in detail. The protective device and methods are not limited to the specific embodiments described herein, but rather, components of the protective device and/or the switchgear and/or steps of the method may be utilized independently and separately from other components and/or steps described herein. For example, the protective device and methods may also be used in combination with other power systems and methods, and are not limited to practice with only the electrical system as described herein. Rather, the exemplary embodiments can be implemented and utilized in connection with many other electrical applications.