GAS-INSULATED INTERRUPTER

Abstract: A gas-insulated interrupter comprising an interrupting unit 10, a hermetically-sealable housing 11 enclosing the interrupting unit therein, and a pair of rigid terminal conductors 146, 156 connected to the interrupting unit at spaced positions is disclosed. The housing has formed therein a single opening sufficiently large to allow the interrupting unit and the terminal conductors as assembled to pass therethrough. The large single opening in the housing is closed by a single closure member 12 rigidly supporting the terminal conductors and hermetically closing the opening in the housing while mechanically rigidly supporting the terminal conductors and the interrupting unit.

Description: BACKGROUND OF THE INVENTION This invention relates to a gas-insulated interrupter, and more particularly to a gas-insulated interrupter of the type in which an interrupting unit is supported by a pair of terminal conductors extending through a hermetically-sealed housing. An example of a conventional gas-insulated interrupter of the type with which the present invention is concerned is illustrated in Fig. 1. In the figure, the gas-insulated interrupter comprises a cylindrical metallic housing 1 including an end plate 2 and having in its cylindrical wall first and second openings 1a and 1b spaced apart from each other. The first opening 1a is hermetically closed by a source side lead-in terminal 4 comprising an electrically insulating molded member 4a and a rigid terminal conductor 4b secured to and extending through the insulating member 4a. The insulating member 4a has formed thereon a flange 4c for attaching the lead-in terminal 4 to the opening 1a. The second opening 1b is also hermetically closed by a load side lead-in terminal 5 similar to the source side lead-in terminal 4. The load side terminal 5 includes an electrically insulating molded member 5a with a flange 5c and a rigid terminal conductor 5b extending through the molded member 5a. Thus, the terminal conductors 4b and 5b are independently mechanically supported by the housing 1 through the insulating molded members 4a and 5a. The inner ends of the first and the second terminal conductors 4b and 5b support an elongated interrupting unit 10 having a stationary contact 6 connected to the first terminal conductor 4b and a movable contact 7 having sliding connectors 8 and 9 for slidably connecting the movable contact 7 to the second terminal conductor 5b. The upper end (as seen in Fig. 1) of the movable contact 7 can be Brought into and out of electrical engagement with the stationary contact 6, and the lower (as seen in Fig. 1) end of the movable contact 7 is connected to an operating mechanism (not shown) as is well known in the art. As described above, the conventional gas-insulated interrupter which the present invention concerns has two separate, relatively small openings 1a and 1b through which the terminal conductors 4b and 5b pass. Therefore, the assembly of the interrupting unit 10 and the connecting operation of the interrupting unit 10 to the terminal conductors 4b and 5b must be performed inside the housing 1. Thus, the assembly operation is difficult and the accuracy of assembling is poor. Also, since a space for the assembly operation is necessary inside the housing, the overall dimension of the interrupter are difficult to reduce. French patent specification 2089315 and US 3745284 relate to high-voltage circuit breakers with gas quenching of the type defined by the pre-characterizing part of claim 1. In both cases, the terminal conductors which are spaced apart and are substantially parallel to one another, extend transversely with respect to an elongate interrupting unit. In each case, the circuit breaker comprises a housing having a pair of openings for receiving the terminal conductors. The construction of the circuit breakers in each case is such that the two terminal conductors and the interrupting unit cannot be assembled and then positioned within the housing in a single step. French patent specification 2152560 relates to a synchronous puffer circuit breaker comprising a bulky vessel of cylindrical shape for withstanding high pressures of 10 atmospheres. The circuit breaker comprises a pair of terminal conductors electrically insulated from one another but supported by a complex arrangement of insulating and non-insulating materials. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a gas-insulated interrupter in which assembly of the interrupting unit is easy. Another object of the present invention is to provide a gas-insulated interrupter in which the interrupting unit and the terminal conductors can be assembled outside the interrupter housing. According to the present invention, there is provided a gas-insulated interrupter comprising: an elongate hermetically-sealable housing for enclosing an elongate interrupting unit coaxially disposed with respect to the housing; a pair of rigid terminal conductors connected to and extending from the interrupting unit at spaced apart positions such that the conductors are parallel to each other and extend transversely with respect to the elongate direction of the interrupting unit; and an electrically insulating gas disposed within the housing; characterized in that the pair of rigid terminal conductors are supported by a one-piece closing means integrally moulded from an electrically insulating material, the housing is provided with a single opening sufficiently large to allow the elongate interrupting unit to pass therethrough when assembled with the terminal conductors and the closing means during assembly of the gas-insulated interrupter and the closing means hermetically closes the opening thereby mechanically and rigidly supporting the terminal conductors and the interrupting unit. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more readily apparent from the following detailed description of the preferred embodiment of the invention taken in conjunction with the accompanying drawing, in which: Fig. 1 is a sectional view illustrating a conventional gas-insulated interrupter of the type to which the present invention concerns; and Fig. 2 is a sectional view illustrating a gas-insulated interrupter of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT A gas-insulated interrupter of the present invention as illustrated in Fig. 2 comprises a metallic hermetically-sealable housing 11 in which an interrupting unit 10 o the type described in conjunction with Fig. 1 is disposed. The housing 11 has formed therein a large opening 11a. The dimensions of the opening 11a are such that they allow the interrupting unit 10 as assembled to pass therethrough with the terminals connected. The interrupting unit 10 comprises a stationary contact 6,, a movable contact 7, and sliding sleeve connectors 8 and 9. Although not illustrated, the movable contact 7 is connected to an operating mechanism for movement between closed and open positions, as is well known. The stationary contact 6 of the interrupting unit 10 is rigidly supported by the inner end of a rigid terminal conductor 14b of a source-side terminal 14, and the stationary sleeve 9 of the sliding sleeve connectors 8 and 9 of the interrupting unit 10 is rigidly supported by the inner end of a rigid terminal conductor 15b of a load-side terminal 15. Therefore, the terminal conductors 14b and 15b extend parallel to each other and are spaced apart by a distance corresponding to the length of the interrupting unit 10. The terminal conductors 14b and 15b are both supported by a single electrically insulating molded member 12. The insulating molded member 12 in the illustrated embodiment is a single-piece member having a plate-like portion 12a and two parallel bushing-like portions 12b and 12c through which the terminal conductors 14b and 15b, respectively, extend. In other words, the molded member 12 is a member in the shape of two flanged bushing-like insulators 12b and 12c connected a their flanges 12a to each other to form a one-piece terminal member 12. The terminal member 12 is secured to a flange of the opening 11a at the flange 12a or at the edge of the plate portion 12a by a ring-shaped retainer 13 including bolts (not shown). The hermetic housing 11 is filled with an electrically-insulating gas such as SF₆ gas. When the unillustrated operating mechanism pulls down the movable contact rod 7, the sliding sleeve connector 8 fixedly mounted on the movable contact rod 7 slides along the connector sleeve 9 rigidly secured to the inner end of the second terminal conductor 15b while maintaining the electrical connection therebetween. This movement of the movable contact rod 7 causes the movable contact 7 to separate from the stationary contact 6 to open the circuit to be switched. As has been described, the hermetic housing of the gas-insulated interrupter of the present invention has formed therein a large single opening sufficiently large to allow the passage of the interrupting unit as assembled together with the terminal conductors therethrough, and the large single opening is closed by a single electrically insulating member. Therefore, the assembly of the interrupting unit and the connecting operation of the interrupting unit to the terminal conductors can be performed outside the housing. Thus, the assembling operation is easy and accuracy of assemblage is superior. Also, since a space for assembling operation is not necessary inside the housiig, the overall dimension of the interrupter can greately be reduced.

Claims: A gas-insulated interrupter comprising: an elongate hermetically-sealable housing (11) for enclosing an elongate interrupting unit (10) coaxially disposed with respect to the housing; a pair of rigid terminal conductors (14b, 15b) connected to and extending from the interrupting unit (10) at spaced apart positions such that the conductors are parallel to each other and extend transversely with respect to the elongate direction of the interrupting unit (10); and an electrically insulating gas disposed within the housing (11); characterized in that the pair of rigid terminal conductors (14b, 15b) are supported by a one-piece closing means (12, 14, 15) integrally moulded from an electrically insulating material, the housing is provided with a single opening (11a) sufficiently large to allow the elongate interrupting unit (10) to pass therethrough when assembled with the terminal conductors and the closing means during assembly of the gas-insulated interrupter, and the closing means hermetically closes the opening (11a) thereby mechanically and rigidly supporting the terminal conductors (14b, 15b) and the interrupting unit (10).

Inventors: FUJISAWA, OSAMU, HASEGAWA, HIROSHI, OZAKI, YUKIO, SAKAI, RYUKICHI
Applicants: MITSUBISHI DENKI KABUSHIKI KAISHA
Application year: 1985
Main classification: H02B13
IPC codes: H02B13, H01H31, H01H33