US3790861A

US3790861A - Switchgear with fuses individually mounted on fuse carriers and switches therefor for interlocks

Info

Publication number: US3790861A
Application number: US00295826A
Authority: US
Inventors: G Sakats
Original assignee: S&C Electric Co
Current assignee: S&C Electric Co
Priority date: 1972-10-10
Filing date: 1972-10-10
Publication date: 1974-02-05
Anticipated expiration: 1991-02-05
Also published as: CA970809A

Abstract

High voltage fuses are mounted on individual carriers for movement into and out of engagement with stationary contacts under the control of a carriage that can be connected to any or all of the carriers. Switches are arranged to connect any or all of the fuses in circuits. A locking bolt holds each fuse carrier in closed position and can be moved to locking position only when the fuse carrier is closed. Interlocks between the fuse carriers and operators for the switches prevent opening the carrier when the switches are closed and closure of the switches when the carriers are open.

Description

United States Patent 1 91 1 1 3,790,861 Sakats I Feb. 5, 1974 SWITCHGEAR WITH FUSES 3,339,118 8/1967 Hamer 317/114 INDIVIDUALLY MOUNTED 0N FUSE 3,576,509 4/1971 Bernatt 337/8 Harry 3 l FOR INTERLOCKS Gerald Sakats, Arlington Heights, 111.

S & C Electric Company, Chicago, Ill.

Filed: Oct. 10, 1972 Appl. No.: 295,826

Inventor:

Assignee:

References Cited UNITED STATES PATENTS 5/1971 Keough 317/114 Primary Examiner-James R. Scott Assistant Examiner-Gerald P. Tolin Attorney, Agent, or Firm-Kirkland & Ellis 5 7] ABSTRACT High voltage fuses are mounted on individual carriers for movement into and out of engagement with stationary contacts under the control of a carriage that can be connected to any or all of the carriers. Switches are arranged to connect any or all of the fuses in circuits. A locking bolt holds each fuse carrier in closed position and can be moved to locking position only when the fuse carrier is closed. Interlocks between the fuse carriers and operators for the switches prevent opening the carrier when the switches are closed and closure of the switches when the carriers are open.

1 Claims, neEis les PATENTED FEB 5 I974 SHEET 10F 7 sum s or 7 g PATENTED FEB 51914 HM J PAIENIEHFEB i n 3.790.861

SHEET 7 BF 7 1 SWITCHG-EAR WITH FUSES-INDIVIDUALLY MOUNTED ON FUSE CARRIERS AND SWITCHES THEREFOR FOR INTERLOCKS out-of operative position'underthe control of acarriage arrangedzto move anyrorlallof the-carriers to and from the operative position; :to lock each carrier in its .fuse

closedzposition and to permit operationof the lock only when the carrier is in the closed position; to lock the carriage securely to the carrier or-carriersto be withdrawn; to provide a switch foreach fuse and an operator for each switch; and -to interlock each fuse carrier and the respective switch operator to prevent opening of the carrier when the switch is closed and to prevent closing of the switch when the carrier is open.

In the drawings: FIG. 1 is a perspective view of a portion of switchgear in which the present invention is embodied, one of the fuse carriers being shown in the withdrawn position by the carriage in a corresponding position.

FIG. 2 is a horizontal sectional view taken generally along line 2-2 of FIG. 1.

FIG. 3 is a view, in front elevation, of the construction shown in FIG. 2.

FIG. 4 is a horizontal sectional view at an enlarged scale taken generally along line 44 of FIG. 3.

FIG. 5 is a view, in front elevation, of the construction shown in FIG. 4.

FIG. 6 is a vertical sectional view taken generally along line 6--6 of FIG. 5.

FIG. 7 is a perspective view of one of the striker plates.

FIG. 8 is a vertical sectional view taken generally along line 88 of FIG. 1.

FIG. 9 is a vertical sectional view taken generally along line 9-9 of FIG. 8.

FIG. 10 is a vertical sectional view at an enlarged scale taken generally along line 10-10 of FIG. 8.

FIG. 11 is a plan view of one of the handles and the associated locking cam mounted thereon.

FIG. 12 is a top plan view of the locking cam.

FIG. 13 is a perspective view of the locking cam showing the inclined cam surfaces.

FIG. 14 is an elevational view of the locking bolt actuator.

FIG. 15 is a view, in side elevation looking from left to right of the locking bolt. actuator shown in FIG. 14.

FIG. 16 is a horizontal sectional view at an enlarged scale taken generally alongline 16-l6 of FIG. 14.

FIG. 17 is a view, in front elevation, of the switch interlock means.

FIG. 18 is a view of the switch interlock means shown in FIG. l7'looking from right to left, the switch interlock'means being shown in the switch closed position.

'FIG. 19 is a view, similar to FIG. 17, but showing the switch interlock means in the switch open position.

FIG. 20 is a view, similar to FIG. 18, showing the switch'interlock'means in the switch open position.

line contacts 13. At their other ends the fuses 11 have.

contacts 14 that are arranged to engage and disengage switch contacts 15 which are connected to switch blades 16. The switch blades 16 are arranged to engage line contacts 17. Operators, indicated by broken lines at 18, are provided for individually operating the switch blades 16 from and to the switch closed positions. They are provided with manually operable handles 19, also shown by broken lines. The operators 18 can be of conventional construction such as that disclosed in Bernatt et al. US. Pat. No. 3,563,102 issued Feb. 16, 1971. However, it will'be understood that other operators can be employed.

As will appear hereinafter the fuses 11 are individu-' ally mounted for movement into and out of engagement with the line contacts 13 and switch contacts 15. However, provision is made for preventing movement of the fuses 11 from the engaged position as long as the respective switch blade 16 is closed. Only after the respective switch blade 16 is opened can the corresponding fuse 1 1 be withdrawn for servicing or replacement.

Since the various contacts and switches are of conventional construction only portions of them are illustrated and described herein.

Referring now to FIG. 1 it will be observed that the reference character 22 designates, generally, a metallic housing that is provided with three fuse carriers each of which is indicated at 23. Each fuse carrier 23 can be considered to comprise the fuse 11 mounted thereon and extending from an exhaust control device 24 which is carried by an insulator 25 that is mounted on a rear plate 26, FIG. 2, which forms a part of a carrier front housing that is indicated, generally at 27. The carrier front housing 27 is provided with a front plate 28 and end plates 29.

In order to locate accurately the fuse carrier 23 in the housing 22, upper and

lower openings

30 and 31 are provided in the rear and

front plates

26 and 28 for engagement by upper and lower locating

pins

32 and 33 that are mounted on angle frame members one of which is indicated at 34 in FIG. 1. A reason for this accurate location of the carrier 23 and particularly of the carrier front housing 27 with respect to the housing 22 I and lower locating

pins

32 and 33 are positioned on each side of the carrier front housing 27 so that both sides are accurately located with respect to the housing 22 when the fuse carrier 23 occupies the inserted or fuse closed position.

It is desirable that any one or two or all three of the fuse carriers 23 be arranged to be withdrawn and re placed from and in the housing 22. For this purpose a carriage, indicated generally at 38, is employed. The carriage 38 comprises upper and lower channel shaped frame members .39 and 40 that are suitably slidably mounted in the housing 22. As will be understood readily the channel shaped

frame members

39 and 40 are so mounted within the housing 22 that they move along the predetermined path with respect to the housing 22 and with a minimum of deviation therefrom. The

frame members

39 and 40 are interconnected by a vertical panel 41 on which handles 42 are pivoted for controlling the operation of a locking mechanism individual to each of the fuse carriers 23. As shown in FIG. 11 each handle 42 has a spacer sleeve 43 extending therefrom and also a shaft 44. At the inner end of the shaft 44 there is a locking cam 45, FIGS. 8, 12 and 13 which is secured against rotation by a key 46. As shown in FIG. 9 a bearing sleeve 47 is secured to the rear side of the panel 41 and provides a bearing support for the respective shaft 44. As seen in FIGS. 1 and 9 an opening 48 is provided in the front plate 28 of each fuse carrier 23 to permit the insertion of the locking cam 45 of the respective handle 42 therethrough.

As illustrated in FIGS. 3, 4, 5, l4, l and 16 a cam receiving slot 49 is provided in a circular locking bolt actuator 50 which is pivotally mounted between the rear and

front plates

26 and 28 of the carrier front housing 27. It will be understood that the cam receiving slot 49 is of about the same dimensions as the opening 48 in the front plate 28. Also the cam receiving slot 49 is only slightly larger than the locking cam 45 with the clearance therebetween being only that necessary to facilitate entry and withdrawal of the locking cam 45 to and from the cam receiving slot 49.

i The locking bolt actuator 50 is pivotally mounted on the rear side of the front plate 26 by means of pins 51 that extend rearwardly therefrom and are secured as by welding thereto. The pins 51 extend through arcuate slots 52 in the locking bolt actuator 50 and have heads 53 at their distal ends that are located in arcuate slots 54 which are substantially wider than the arcuate slots 52. Circular openings 54' at one end of each of the arcuate slots 54permit entry of the heads 53 into the arcuate slots 54. Pivotally secured to diametrically opposite locations on the locking bolt actuator 50 are links 55. They are movable endwise and with respect to slots 55 in the periphery of the locking bolt actuator 50. The other ends of the links 55 are pivotally connected to endwise movable locking bolts-56 which are guided for translatory movement by guides 57. Only one of the guides 57 is illustrated in FIGS. 4 and 5 of the drawings.

" As here shown, openings 58 are provided in the end plates 29 through which the locking bolts 56 are movable. Also they are movable through openings 59 in the angle frame members 34. When the locking bolts 56 are extended, as shown in FIGS. 4 and 5, the respective fuse carrier 23 cannot be withdrawn from the housing 22.

It is desirable that the locking cam 45, when inserted into the cam receiving slot 49 in the respective locking bolt actuator 50 have a rigid connection therewith. For this purpose inclined cam surfaces 62, FIGS. 12 and 13, are provided on the locking cam 45 for cooperation with inclined surfaces 63, FIGS. 4 and 7, of striker platesj64. As shown inFlG. 5 the striker plates 64 are I located on the inside of the front plate 28 above and below the opening 48 therein through which the locking cam 45 is inserted into the cam receiving slot 49 of the locking bolt actuator 50. In order to resist the torque that is applied when the handle 42 is pivoted to the carrier locking position, openings 65, FIG. 1, are provided in the front plate 28 for receiving locating pins 66 that extend rearwardly from the vertical panel 41 as illustrated in FIGS. 8 and 10.

It will be understood that insulating barriers, not shown, may be mounted on the fuse carriers 23 and around the energized parts thereon. Brackets 67, FIG. 8, mounted on the rear plate 26 of the carrier front housing 27 are arranged to mount such barriers. Since they form no part of the present invention and since their showing would obscure certain parts of the present construction, they have been omitted.

In the withdrawn position of a fuse carrier 23, as shown'in FIG. 1 for example, it is undesirable that the handle 42 in the unlocked position be permitted to pivot to the locked position. If such operation were not prevented, it would be possible to move the carriage 38 into the housing 22 with the locking bolts 56 in the extended positions. Accordingly interlock levers 70, FIGS. 4, 5 and 6 are employed at each end of the carrier front housing 27 Each interlock lever 70 is pivoted at 71 in a plane that extends at right angles to the path of the respective locking bolt 56. A torsion spring 72 acts to bias its interlock lever 70 into the path of the respective locking bolt 56 when the respective fuse carrier 23 is withdrawn. This is shown by broken lines in FIG. 6. When the fuse carrier 23 is shifted to the closed position by a corresponding movement of the carriage 38, the upper locating pin 32 engages the distal end of the respective interlock lever 70 and moves it out of the path of the respective locking bolt 56. Thereafter it is possible to shift the handle 42 from the unlocked position to the locked position and extend the locking bolts 56 to the locked positions shown in FIGS. 4 and 5. It will be understood that only a single interlock lever 70 is required since the locking bolts 56 are mechanically interconnected through the locking bolt actuator 50. However, if desired, an interlock lever 70 can be provided for each of the locking bolts 56.

Referring now particularly to FIGS. 2 and 3 it will be noted that fuse interlock means, indicated generally at 75, is arranged to interlock each fuse carrier 23 with the respective switch means or switch operator 18. The fuse interlock means 75 includes a notch 76 near the distal end of the locking bolt 56 for engagement by an arm 77 of an L-shaped locking lever 78, the other arm 80 of which is secured to and pivots with a shaft 81 that is journaled in a bearing sleeve 82. The bearing sleeve 82 is secured to a frame member 84 which forms a part of the metallic housing 22, FIG. 2. As will appear hereinafter, as long as the operator 18 individual to the locking bolt 56 is in the switch closed position, the arm 77 of the locking lever 78 extends through the notch 76 and prevents withdrawal of the respective locking bolt 56. Thus it is not possible to withdraw the respective fuse carrier 23 under these conditions.

FIGS. 2 and 3 also show, generally at 86, switch interlock means arranged to prevent closure of the respective Switchblade 16 when the respective fuse carrier 23 is not in the fully closed position with the respective locking bolt 56 in locking position. The details of the switch interlock means 86 are shown more clearly in FIGS. 17 and 18. Here itwill be observed that an arm 87 is secured to the shaft 81 at the end opposite to that on which the locking lever 78 is secured. A link 88 interconnects the arm 87 with a bell crank 89 which is suitably pivoted on the lower end of the support bracket 83. A link 90 interconnects the bell crank 89 with a sector plate 91, FIGS. 2 and 3, which is directly connected to and is movable with the handle 19 of the respective operator 18. An arcuate slot 92 is formed in the sector plate 91 in order to effect operation of the link 90 only near the end of the opening stroke of the handle 19. By this time the respective Switchblade 16 will have been opened so that, during the final opening movement of the handle 19 to the open position as shown in FIG. 1, for example, the link 90 is tensioned to act through the bell crank 89, link 88 and arm 87 to shift thearm 77 of the L-shaped locking lever 78 out of the notch 76 in the respectively locking bolt 56. Thereafter, the respective fuse carrier 23 can be withdrawn.

In order to prevent operation of the handle 19 and thereby of the respective switch blade 16 to the switch closed position in the absence of the respective fuse carrier 23, provision is made for preventng any pivotable movement of the handle 19. This is accomplished through the provision of a flipper 93 that is pivoted at 94 on cars 95 that extend from the bearing sleeve 82. A torsion spring 96 reacts against the flipper 93 in the absence of the respective locking bolt 56 to shift the flipper 93 into the path of the other arm 80 of the L- shaped locking lever 78 as illustrated in FIGS. 19 and 20. This action prevents any movement of the locking lever 78. Since it is connected through the switch interlock means 86 to the sector plate 91, it is not possible to pivot the handle 19 from the open position. When the respective fuse carrier 23 is returned to the fuse closed position and the respective locking bolt 56 is moved to the locked position, as shown in FIG. 18, the distal end engages the flipper 93 and shifts it to a position out of the path of the other arm 80 of the locking lever 78. Thereafter, the handle 19 can be pivoted to close the respective switch blade 16.

FIG. 3 shows additional fuse interlock means 75 and switch interlock means 86 that are associated with the next fuse and switch combination. However, their operation is identical with that described hereinbefore.

With a view to preventing unauthorized access to the handles 19 for the switches and the handles 42 for the fuses removable front panels 99, FIG. 2, can be slidably mounted on the front side of the metallic housing 22. For convenience the metallic housing 22 can be extended to the left, as viewed in FIG. 1, to provide for receipt of equipment in duplicate of that here illustrated. In such case the additional switches can be located adjacent the switches here illustrated and the fuses can be located at the left end of the extended housing 22.

I claim:

1. Switchgear comprising a metallic housing, a plurality of sets of fuse contacts mounted in insulated spaced relation in said housing, a plurality of unconnected fuse carriers individually removably mounted on said housing, a fuse carried by each of said fuse carriers for movement into and out of contact engagement with a respective set of fuse contacts, a carriage slidably mounted on said housing independently of and overlying said fuse carriers, coupling means on said carriage for selectively connecting said carriage to one or more of said fuse carriers for withdrawing said one or more fuse carriers and the fuse or fuses carried thereby from and returning the fuse or fuses to contact engagement with the respective set of contacts, a plurality of switch means in insulated spaced relation in said housing, each said switch means associated with a respective fuse for connecting said respective fuses in and disconnecting said respective ruses from an electrical circuit, switch operating means for independently operating a respectively associated switch means, and locking flipper means for preventing operation of said switch operating means when said fuse carrier is withdrawn from said housing.

2. Switchgear according to claim 1 wherein each fuse carrier includes: a locking bolt movable into and out of locking engagement with said housing, and a coupling cam receiver; and said coupling means includes a manually operable coupling cam pivotally mounted on said carriage individual to each of said fuse carriers for engaging the respective coupling cam receiver to cause movement of said locking bolt out of locking engagement with said housing when said coupling cam and said cam receiver are engaged and into locking engagement with said housing when said coupling cam and said cam receiver are disengaged and for making mechanical connection to the respective fuse carrier for withdrawing and returning said fuse carrier to the housmg.

3. Switchgear according to claim 1 wherein each fuse carrier includes: a locking bolt actuator, a locking bolt connected to said actuator and movable by said actuator into and out of lock-engagement with said housing, and a coupling cam receiving aperture in said actuator; and said coupling means includes manually operable locking cams pivotally mounted on said carriage individual to each fuse carrier for entering the respective aperture to engage said actuator to pivot said locking bolt actuator to cause said locking bolt to move into and out of locking engagement with said housing and for making mechanical connection to the respective fuse carrier for withdrawing and returning the same as aforesaid.

4. Switchgear according to claim 3 wherein said carriage comprises upper and lower frame members slidably mounted on said housing and interconnected at one end by a vertical panel carrying said locking cams on the side facing said fuse carriers, and handles on the other side of said panel connected to the respective locking cams.

5. Switchgear according to claim 3 wherein aninterlock lever is pivotably mounted on each fuse carrier adjacent each of said locking bolts and is biased with respect to said locking bolts to move into the path of said locking bolts to prevent movement thereof to locking position when said fuse carrier is removed from said housing and means on said housing for engaging each interlock lever to move the same out of said path when said fuse carrier occupies its fully closed position.

6. Switchgear according to claim 5 wherein each interlock lever is movable in a plane parallel to the path of said carriage, and pin means on said housing engage the respective interlock lever to move it out of the path of the respective locking bolt when the respective fuse carrier is slid to its fully closed position.

7. Switchgear according to claim 1 wherein guide means on said housing and on said carriage interfit with said fuse carriers to direct accurately each fuse into engagement with the set of fuse contacts individual thereto when said fuse carriers are moved to their closed positions.

8. Switchgear according to claim 7 wherein an interlock lever is pivoted on each fuse carrier and is biased with respect to the locking bolt thereon into its path to prevent movement thereof to locking position, said guide means on said housing engaging each interlock lever to move the same out of said paths when said fuse carrier occupies its fully closed position.

9. Switchgear comprising a metallic housing, a plurality of sets of fuse contacts mounted in insulated spaced relation in said housing, a plurality of unconnected fuse carriers individually slidably mounted on said housing, a fuse carried by each of said fuse carriers for movement into and out of contact engagement with a respective set of fuse contacts, a carriage slidably mounted on said housing independently of and overlying said fuse carriers, coupling means on said carriage for selectively connecting said carriage to one or more of said fuse carriers for withdrawing said one or more fuse carriers and the fuse or fuses carried thereby from and returning the fuse or fuses to contact engagement with the respective set of contacts, a plurality of switch means in insulated spaced relation in said housing each of said switch means associated with a respective fuse for connecting said respective fuse in and disconnecting said respective fuse from a circuit, and a switch operating means for independently operating a respectively associated switch means, and fuse interlock means on each fuse carrier arranged to prevent withdrawal thereof when the switch operating means individual thereto is in the closed position, and locking flipper means operated by each switch operating means is arranged to prevent closure of its switch means when the fuse carrier individual thereto is withdrawn from said housing.

10. Switchgear according to claim 9 wherein lost motion means between each switch operating means and the respective locking flipper means effect operation of the latter to permit withdrawal of the respective fuse carrier near the end of the opening stroke of said operating means for the respective switch means.

11. Switchgear according to claim 9 wherein each fuse carrier includes: a pivotable locking bolt actuator, a locking bolt connected to said actuator and movable by said actuator into and out of locking engagement with said housing, and a cam receiving slot in said actuator; and said coupling means includes a manually operable locking cams pivotally mounted on said carriage individual to each said fuse carriers for entering the respective slot to engage said actuator to pivot said locking bolt actuator from and to locking position and make mechanical connection to the respective fuse carrier for withdrawing and returning the same as aforesaid; and said switch operating means includes means for interconnecting each locking bolt for preventing movement of the respective locking bolt to unlocked position when said switch means occupies the switch closed position/ 12. Switchgear according to claim 11 wherein said locking bolt has a transverse notch adjacent its distal end, and said means interconnecting said locking bolt includes a locking lever for entering said transverse notch to prevent withdrawal of said locking bolt and the respective fuse carrier when said switch means occupies the closed position.

13. Switchgear according to claim 12 wherein said locking lever is L-shaped with one arm arranged to enter said notch and the other arm pivoted at its distal end and mechanically connected to the respective switch operating means.

14. Switchgear-according to claim 13 wherein said locking flipper means is a flipper biased into the path of said other arm of said L-shaped locking lever for preventing pivotal movement thereof when the respective fuse carrier is withdrawn to prevent opening of the respective switch means, and said flipper is shifted out of the path of said L-shaped locking lever by said locking bolt when the respective fuse carrier is closed and said locking bolt occupies its locked position.

Claims

2. Switchgear according to claim 1 wherein each fuse carrier includes: a locking bolt movable into and out of locking engagement with said housing, and a coupling cam receiver; and said coupling means includes a manually operable coupling cam pivotally mounted on said carriage individual to each of said fuse carriers for engaging the respective coupling cam receiver to cause movement of said locking bolt out of locking engagement with said housing when said coupling cam and said cam receiver are engaged and into locking engagement with said housing when said coupling cam and said cam receiver are disengaged and for making mechanical connection to the respective fuse carrier for withdrawing and returning said fuse carrier to the housing.

5. Switchgear according to claim 3 wherein an interlock lever is pivotably mounted on each fuse carrier adjacent each of said locking bolts and is biased with respect to said locking bolts to move into the path of said locking bolts to prevent movement thereof to locking position when said fuse carrier is removed from said housing and means on said housing for engaging each interlock lever to move the same out of said path when said fuse carrier occupies its fully closed position.

11. Switchgear according to claim 9 wherein each fuse carrier includes: a pivotable locking bolt actuator, a locking bolt connected to said actuator and movable by said actuator into and out of locking engagement with said housing, and a cam receiving slot in said actuator; and said coupling means includes a manually operable locking cams pivotally mounted on said carriage individual to each said fuse carriers for entering the respective slot to engage said actuator to pivot said locking bolt actuator from and to locking position and make mechanical connection to the respective fuse carrier for withdrawing and returning the same as aforesaid; and said switch operating means includes means for interconnecting each locking bolt for preventing movement of the respective locking bolt to unlocked position when said switch means occupies the switch closed position.

12. Switchgear according to claim 11 wherein said locking bolt has a transverse notch adjacent its distal end, and said means interconnecting said locking bolt includes a locking lever for entering said transverse notch to prevent withdrawal of said locking bolt and the respective fuse carrier when said switch means occupies the closed position.

14. Switchgear according to claim 13 wherein said locking flipper means is a flipper biased into the path of said other arm of said L-shaped locking lever for preventing pivotal movement thereof when the respective fuse carrier is withdrawn to prevent opening of the respective switch means, and said flipper is shifted out of the path of said L-shaped locking lever by said locking bolt when the respective fuse carrier is closed and said locking bolt occupies its locked position.