GB2376799A

GB2376799A - Multipole switching device

Info

Publication number: GB2376799A
Application number: GB0214002A
Authority: GB
Inventors: Franz Boeder; Bogdan Zabrocki; Guido Dedenbach; Guido Eifert
Original assignee: Moeller GmbH
Current assignee: Eaton Industries GmbH
Priority date: 2001-06-19
Filing date: 2002-06-18
Publication date: 2002-12-24
Anticipated expiration: 2022-06-18
Also published as: FR2826174B1; ITMI20021318A1; GB2376799B; FR2826174A1; DE10129505C1; GB0214002D0

Abstract

A multipole switching device 2 has a two-part housing. A common switch chamber housing 12, consisting of an upper part 36 and a lower part 38 has a number of switch chambers 34 corresponding to the number of poles. An operating mechanism 18 on the upper part 36 is connected with its actuating member 40 via slots 42 to connecting elements 16, which connect interrupter shaft sections 15 to each other, on which movable contact arrangements 8 are mounted. Lower part 38, upper part 36 and operating mechanism 18 are connected to each other by securing means 44.

Description

1 2376799

Description

Multipole switching device with double housing The invention relates to a multipole switching device with double housing in particular, although not exclusively,to a circuit breaker or a load-breaking switch for low voltage.

10 A multipole circuit breaker for low voltage with double housing is known from publication EP-0542636-B1, each pole comprising a single-pole block with a parallelepipidic switch chamber housing, having two large side faces and made from insulating material, as well as stationary and movable contacts which are allocated to an arc extinguishing chamber and are arranged in the single-pole block. Several blocks are ranged side by side to form a multipole 15 circuit breaker in a switching device housing comprising a bottom part and top part and made from insulating material. The movable contact is developed as a rotatable contact bridge which cooperates with two opposed, stationary contacts and is mounted in an interrupter shaft section which is arranged transversely roughly in the middle of the switch chamber housing and encompassed by the two large side faces of the switch chamber housing and guided 20 laterally and in the process can simultaneously perform a limited rectilinear movement parallel to these large side faces. The interrupter shaft sections of the individual blocks ranged side by side are mechanically connected to each other by two connecting bars arranged in parallel which run at right angles to the large side faces and are guided with small clearance through diametrically opposed openings worked in the adjacent interrupter shaft 25 sections. The two connecting bars are coupled to a crank with two diametrically opposed crank arms. Each of the named large side faces has two curved oblong holes for the passage with play and displacement of the two connecting bars. An operating mechanism mounted on the top side of one of the single-pole blocks has two metal side plates to which the bearings of the crank as well as a lower rod for the operation of the crank are attached. Spacer plates 30 are inserted between the adjacent single-pole blocks. All the single-pole blocks and spacer plates are connected to each other with the help of positioning rods, the spacer plates having curved oblong holes for the passage of the connecting bars. The positioning rods are guided tightly through openings worked in the side plates of the operating mechanism. The operating mechanism arranged in the switching device housing has an actuating arm which extends

through an opening from the upper part of the switching device housing. Each interrupter shaft section consists of insulating material and has an opening for the passage of the contact bridge. A crank is arranged on each side of the switch chamber housing and the connecting bars pass through all the interrupter shaft sections as well as the two cranks. Because of its 5 relatively large number of parts and the nature of its design, the circuit breaker requires a considerable fitting outlay during assembly.

An example of an operating mechanism for a multipole circuit breaker is to be found in the publication DE-4227213-A1. This operating mechanism consists of an actuating arm housed 10 between two side plates, a supporting lever and a toggle-lever system, connected to a clockwork reservoir, which is connected on one side to an interrupter shaft of the circuit breaker. The supporting lever rests against a release mechanism which, in customary manner by means of thermomagnetic or electronic tripping system, effects a disengagement of the operating mechanism and thus a switching-off of the circuit breaker when predetermined 15 limit values of the pole currents are exceeded. The cited manner of securing the operating mechanism in a single housing does not provide adequate mechanical stability vis-a-vis high pressures inside the switching device, such as occur through arcing as a result of short-

circuits. 20 The publication EP-1037239-A2 discloses a multipole circuit breaker with a switch chamber housing consisting of an upper part and a lower part, in which a number of switch chambers corresponding to the number of poles are arranged next to each other, as well as an interrupter shaft common to all poles, each switch chamber having a stationary contact arrangement and one developed as a swivellable contact bridge, which cooperates with the 25 stationary contact arrangement. Each of the contact bridges is disposed in an interrupter shaft section consisting of insulating material, the adjacent interrupter shaft sections each being connected to each other via separate coupling elements. The coupling elements each comprise two parts developed in the form of tabs, which are connected to each other via a support shaft, and which, on their side facing away from the support shaft, each bear at least 30 two connecting pins extending in axial direction. The interrupter shaft sections each have. on their side facing the corresponding coupling element, recesses to receive the connecting pins.

The transition region of the switch chamber housing between adjacent switch chambers is at

least partially developed as a support for the support shaft of the coupling element connecting the corresponding interrupter shaft sections.

A securing arrangement for an operating mechanism is described in the publication EP 395 5 326 B 1. The side plates each have two T-shaped developments projecting bottom-side which are guided outwards through slits of the lower part of the insulating switching device housing and through essentially rectangular holding disks which are placed in corresponding areas shaped from the bottom part. Through turning of the slightly sloped cross-limbs of each T-

shaped development, their long sides are twisted and thus reduced lengthwise, the result of 10 which is that the cross-limb rests against the associated holding disk and via this outwards against the bottom part in force-locking manner. The side plates and the parts of the operating mechanism housed therein are thereby held fast in the bottom part. The punched-out holding disks are shape-coded, so that they can be placed in the bottom part only in such a way that the flash-free punching edges alone can come into contact with the cross-limbs. Apart from 1 S the fact that this securing arrangement cannot be transferred directly to circuit breakers with double housing, the holding disks disadvantageously require an additional outlay on production, fitting and storage.

An object of preferred embodiments of the invention is therefore to reduce the outlay on 20 fitting when assembling a multipole switching device.

Starting from a switching device of the type named at the outset, the object is achieved according to the invention by the characterizing features of the independent claim, while advantageous further developments of the invention will be found in the dependent claims.

The switch chamber housing common to all poles allows simple fitting of the contact arrangements, the interrupter shaft sections and the connecting elements. The upper and bottom parts equipped in this way can be easily connected in force-locking manner to the fitted operating mechanism by means of the securing elements to form a complete and 30 compact assembly, the working connection between the operating mechanism and the interrupter shaft sections being realised at the same time via the at least one connecting element and a pressure-stable development of the switch chamber housing being guaranteed.

The pressure-stable development prevents in particular the escape of arc gases by

unauthorized routes and the encroachment of arc gases on unwanted parts of the switching device or the electrical system.

The operating mechanism is expediently coupled with the two connecting elements 5 connected to the or a middle interrupter shaft section.

An advantageous development is that the switch chamber housing and the operating mechanism are joined together in a technologically simple and sufficiently pressure-stable manner by means of screwed connections. In particular if, through the use of thread-grooving 10 screws, a selfestablishing connection upon fitting is created between the securing means and corresponding thread housings in the side plates of the operating mechanism.

An advantageous refinement of the invention is the development of the movable contact arrangement as a rotation-symmetrical swivellable contact bridge. The use of the connecting 15 elements to support the interrupter shaft sections also proves advantageous.

Further details and advantages of the invention will be seen in the following exemplary embodiment which is explained with the help of figures; in which: 20 Figure 1: shows a switching device according to the invention in exploded perspective representation; Figure 2: shows the switch chamber housing and the operating mechanism from Fig l in exploded perspective representation; Figure 3 shows the switch chamber housing and the operating mechanism from Fig l 25 in assembled perspective representation Figure 1 shows a three-pole switching device 2 for low voltage made as a circuit breaker and provided with a double housing. Allocated to each of the three poles is a stationary contact arrangement with two stationary contact bars 4 and 6, a movable contact arrangement 30 8 in the form of a rotation-symmetrical contact bridge and two arcextinguishing chambers 10 which are arranged in a switch chamber housing 12 made of insulating material Each movable contact arrangement 8 is housed in a middle or outer interrupter shaft 14 and IS respectively consisting of insulating material. The three interrupter shaft sections 14, 15 are

s connected to each other in twist-resistant manner in the switch chamber housing 12 via two connecting elements 16. The structure of this contact system and its incorporation and housing respectively into and in the switch chamber housing 12 is described in detail in the already cited EP1037239-A2. The connecting elements 16 are coupled with an operating 5 mechanism 18, which has inter alla two side plates 20 and an actuating arm 22. The switch chamber housing 12 and the operating mechanism 18 are disposed in a switching device housing 28, consisting of a bottom part 24 and a top part 26, made of insulating material. The top part 26 is provided with a cover 30 which can be swivelled away and an opening 32 out through which the actuating arm 22 juts. In the finished state of the switching device 2 the 10 bottom part 24 and the top part 26 are screwed to each other over the switch chamber housing 12. According to Fig. 2 a number of switch chambers 34 corresponding to the number of poles are arranged next to each other in the switch chamber housing 12 for the stationary and movable 15 contact arrangements 4, 6, 8 and the arcextinguishing chambers 10 The switch chamber housing 12 common to all three poles consists of an upper part 36 and a lower part 38.

According to Figs. 2 and 3 the operating mechanism 18 sits on the upper part 36 above the middle pole. It is connected with its actuating member 40 via two inlets 42 let into the upper part 36 to the two connecting elements 16 between the middle interrupter shaft section 14 and 20 the laterally adjacent outer interrupter shaft sections 15. The lower part 38, the upper part 36 and the operating mechanism 18 are connected to each other in force-locking manner via common securing means 44, and in addition to the force closure acting parallel to the longitudinal direction of the securing means 44, there are additional form closures acting perpendicular thereto through the shaping of upper part 36 and lower part 38. Provided as 25 securing means 44 are four bolts which engage, via continuous vertical bores 46 in the lower part 3X, with thread housings 48 in the side plates 20, passages 5() being provided in the upper part 36 for the thread housings 48. Through the use of threaded screws, a self establishing connection between the securing means 44 and the thread housings 48 is created upon the assembly of lower part 38, upper part 36 and operating mechanism 18.

List of reference numbers: 2 Switching device 28 Switching device housing 4, 6 Contact bars 30 Cover 5 8 Movable contact arrangement 32 Opening 10 Arc-extinguishing chamber 34 Switch chambers 12 Switch chamber housing 36 Upper part 14, 15 Interrupter shaft section 38 Lower part 16 Connecting element 40 Actuating member 10 18 Operating mechanism 42 Inlet 20 Side plate 44 Securing means 22 Actuating arm 46 Vertical bore 24 Bottom part 48 Thread housing 26 Top part 50 Passage

Claims

),! ,... Claims

An) 1. A multipole switching device Fir low voltage with double housing, in which - in a switch chamber housing. at least one stationary contact arrangement, a movable 5 contact arrangement and at least one extinguishing chamber is allocated to each pole, - the movable contact arrangement is housed in an interrupter shaft section, made from insulating material, which for its part is housed at least indirectly in the switch chamber housing, 10 - the interrupter shaft sections are connected to each other via connecting elements, - the connecting elements are coupled with an operating mechanism which has two side plates and an actuating arm and - switch chamber housing and operating mechanism are arranged in a switching device housing, consisting of a bottom part and top part, the actuating arm jutting 15 out through an opening worked in the top part, wherein - a common switch chamber housing, consisting of an upper part and a lower part, is provided, in which a number of switch chambers corresponding to the number of poles are arranged next to each other, 20 - the operating mechanism sits on the upper part and is connected with an actuating member through at least one inlet in the upper part to at least one of the connecting elements and - lower part, upper part and operating mechanism are connected to each other at least in force-locking manner via common securing means.
2. A switching device according to claim 1, wherein the operating mechanism sits above the or a middle switch chamber and is connected via two inlets to the two connecting elements between the middle interrupter shaft section.and the adjacent interrupter shaft sections.
3. A switching device according to any one of the previous claims, wherein there is provided, as securing means, bolts which engage, via continuous vertical bores in the )

!) lower part, with thread housings in the side plates, passages being provided in the upper part for the thread housings.
4. A switching device according to claim 3, wherein the securing means are threaded 5 screws.
5. A switching device according to any one of the previous claims, wherein the movable contact arrangement is developed as a swivellable contact bridge.

10
6. A switching device according to any one of the previous claims, wherein the interrupter shaft sections are housed in the switch chamber above the connecting elements.
7. A switching device substantially as described herein and with reference to the drawings hereof.

7. switching device substantially as described herein and with reference to the drawings hereof.

Amendments to the claims have been filed as follows 1. A multipole switching device for low voltage with double housing, comprising, a switching device housing, consisting of a bottom part and top part, a common switch chamber housing and an operating mechanism arranged in the switching device housing, 5 the common switch chamber housing consisting of an upper part and a lower part in which a number of switch chambers corresponding to the number of poles are arranged next to each other, the common switch chamber housing having at least one stationary contact arrangement, a movable contact arrangement and at least one extinguishing chamber allocated to each pole, lO each movable contact arrangement being housed in an interrupter shaft section, which interrupter shaft section is made from insulating material and is housed in the common switch chamber housing, each interrupter shaft section being connected to each other via connecting elements, the operating mechanism having an actuating arm, the actuating arm jutting out 15 through an opening worked in the top part, and two side plates having an actuating member, the operating mechanism sitting on the upper part of the common switch chamber housing, the operating mechanism being coupled with the connecting elements by means of an actuating member extending through at least one inlet in the upper part of the 20 common switch chamber housing to at least one of the connecting elements and, the lower part and the upper part of the common switch chamber housing and operating mechanism being connected to each other at least in force-locking manner via common securing means.

2. switching device according to claim 1, wherein the operating mechanism sits above the or a middle switch chamber and is connected via two inlets to the two connecting elements between the middle interrupter shaft section.and the adjacent interrupter shaft sections. 3. A switching device according to any one of the previous claims, wherein there is provided, as secunug means, bolts which engage, via continuous vertical bores in the

i) lower part, with thread housings in the side plates, passages being provided in the upper part for the thread housings.

À. 4. A switching device according to claim 3, wherein the securing means are threaded 5 screws.

5. A switching device according to any one of the previous claims, wherein the movable contact arrangement is developed as a swivellable contact bridge.

10 6. A switching device according to any one of the previous claims' wherein the interrupter shaft sections are housed in the switch chamber above the connecting elements.