EP0003236A1 - Low-tension power circuit-breaker with an insulant housing, subdivided by separating walls - Google Patents

Abstract

A low-voltage circuit breaker (1) has a housing (2) made of insulating material. The housing (2) is divided along a joint (8) into an upper part (3) and a lower part (4). Inside, the housing (2) for receiving the adjacent pole tracks of the multi-pole circuit breaker is divided by partitions (52, 53). The partitions of the upper part (3) and the lower part (4) overlap each other over their entire length, while the outer walls (50, 51) of both housing parts (3, 4) overlap each other essentially over their entire length, i. that is, there are only brief breaks in the overlap. The overlapping of the outer walls and the partition walls ensures that the electrical leakage paths within the insulating material housing and from one insulating material housing to an adjacent insulating material housing are prolonged and that the passage of switching gases into adjacent spaces of a switch and between adjacent switches is prevented.

Description

The invention is concerned with an insulating material housing divided along a parting joint into an upper part and a lower part, and with partition walls which overlap one another in stages between the pole tracks of the switch.

A circuit breaker of this type, in which the step overlap of the partitions is only partially available, is known from US Pat. No. 3,632,939 (corresponds to GB Pat. No. 1,300,203). If such switches are subjected to severe electrical stresses, the switching gases generated in the arcing chambers can also reach the adjacent pole path around the overlapping sections provided in the region of the arcing chambers on the partition walls. In this way, internal flashovers can occur despite the protective measures provided.

Another difficulty arises when the same switches are placed directly next to each other in a switch system or to be mounted on a control panel. In this case, the switching gases emerging at the parting line between the upper and lower part of the one switch can reach the adjacent pole path of an adjacent circuit breaker. In this case, rollovers can also occur. In both endangered areas, ie on the partitions and the outer walls of adjacent switches, electrical creepage distances can also form over time, which prevent safe operation of the switches.

The invention is therefore based on the object to provide a circuit breaker of the type specified, which has a substantially increased security against the transfer of switching gases into adjacent pole tracks of both the same and adjacent switches and against the formation of electrical leakage paths at the points mentioned.

According to the invention, this object is achieved in that the partitions of the upper part and the lower part overlap each other over their entire length and the outer walls substantially over their entire length. Due to the complete overlap of the dividing walls, the switching gases are forced to escape from the circuit-breaker housing only at the designated points without contacting each other. In the area of the outer walls, the essentially complete overlap has proven to be sufficient, in which only short sections, as are required for the lateral routing of electrical auxiliary lines, are excluded from the step overlap.

It is advisable to arrange interruptions of the overlap so that they on adjacent switches different places. Then there is a continuous step overlap between adjacent outer walls of two circuit breakers as well as in the area of the partition walls of one and the same switch. In the context of the invention, this condition can be achieved in that the interruptions of the gradation in both outer walls of a switch are offset from one another. When several identical switches are arranged next to one another, this inevitably means that the interruptions in the gradation are never aligned with one another.

Typically, the tops and bottoms of switches of the present type are held together by fasteners that extend through the bulkheads near the housing ends. Since screws made of metal are generally used as connecting elements, the creepage distance between adjacent pole tracks of the switch is shortened by the thickness of these screws. Furthermore, the screws can cause voltage spreading. To remedy these problems, it is already known to provide cylindrical projections surrounding the screw holes on the partition walls (US Pat. No. 3,632,939). In contrast to this, according to further developments of the invention, the protective measures for extending the creepage distance in the area of the screw holes can be achieved by the design of the partition walls. For this purpose, the partitions of the one housing part can be made forked in the area of the screw holes, the one fork arm forming part of the wall of a screw hole.

According to a further embodiment, the screw holes can be in the raised part of the partitions of the one housing part, ie the upper part or the lower part les, be completely included, and this area containing the screw holes can be received between the raised part of the partitions of the other housing part and an additional raised part. It depends on the thickness of the partition walls available in each case whether one or the other embodiment is cheaper.

For mounting the selector shaft, it is known to provide recesses in the partition walls which also serve as bearing surfaces. At each bearing point, the other half of the bearing is formed by an insert which is pushed into the recess of the partition and closes it. According to a development of the invention, this known arrangement (GB-PS 1 244 890) can be supplemented in that the inserts overlap the components to be stored in the partition walls in stages. In this way, a large creepage distance and increased security against the passage of switching gases is also created in the area of the bearings of the components connecting the adjacent pole tracks. The level training can be done e.g. B. can be achieved by a disc-shaped rib surrounding the component to be stored, which engages in a corresponding groove in the partition and in the insert. Here, too, there is no joint at any point connecting the adjacent pole tracks in a straight line.

In principle, it is possible to design the staged design of the partition walls and the outer walls in such a way that the upper and lower part of the insulating material housing can be displaced in the longitudinal direction. In practice, however, it turns out to be more or less inevitable to carry out the grading with a lateral offset or interlocking at individual points to provide lateral recesses and projections. This creates a positive connection that restricts or prevents longitudinal displacement of the housing parts. In the context of the invention, it is advantageous if the partitions of the upper and lower part of the insulating material housing engage in one another with dimensional accuracy near one of the ends with a lateral projection or recess, while all the other projections and recesses mesh with play in the course of the partition walls. A correct fit of the upper part on the lower part and a force transmission between these parts in the longitudinal direction are thereby achieved without all the other projections and recesses having to be produced with the same accuracy. The connecting screws then only have the task of providing a pressure force between the upper part and the lower part.

If the arrangement is selected in which the screw holes are completely included in the raised part of the partitions of the one housing part and corresponding recesses are provided in the other housing part, it is advantageous to arrange the above-mentioned projections and recesses on the screw holes. This has the advantage that compliance with the tolerances required with regard to the relative position of the screw holes is facilitated and that the projections and recesses can be molded onto the contour of the region of the partition walls surrounding the screw holes.

• Die Fig. 1 zeigt einen Niederspannungs-Leistungsschalter in schematischer Darstellung in einer teilweise geschnittenen Seitenansicht.
• Die Fig. 2 zeigt eine Draufsicht auf das Unterteil eines Leistungsschalters.
• Die Fig. 3 ist eine Draufsicht der Innenseite eines zu dem Unterteil gemäß Fig. 2 gehörenden Oberteiles.

The invention is explained in more detail below with reference to the exemplary embodiments shown in the figures.

• Fig. 1 shows a low-voltage circuit breaker in a schematic representation in a partially sectioned side view.
• 2 shows a plan view of the lower part of a circuit breaker.
• FIG. 3 is a top view of the inside of an upper part belonging to the lower part according to FIG. 2.

4 shows an angled section IV-IV through the upper part according to FIG. 3.

5 shows a section of a partition with a selector shaft and an insert.

A top view of a partially shown lower part of another switch is shown in FIG. 6. The associated section of the upper part is shown in FIG. 7.

The circuit breaker 1 shown in simplified form in FIG. 1 has a housing 2 made of insulating material, for. B. a polyester molding material. As shown in FIG. 1, the housing 2 is divided into an upper part 3 and a lower part 4 along a parting line 8. The current path extends from a connecting terminal 5 via a fixed contact 6 and a movable contact 7 as well as via a flexible conductor 10 and a heating conductor 11 to a further connecting terminal 12 at the other end of the housing 2. The movable contact 7 is through a contact carrier 13 a shift shaft 14 movable. On a hinge pin 15, which connects the movable contact piece 7 and the contact piece carrier 13, a drive lever 16 engages, which can be adjusted manually by means of an actuating handle 17 for switching on and off by means of a mechanism, not shown, known per se. This is moving from the switch-on position shown in FIG. 1 Liche switching piece 7 independently of the actuating handle 17 can also be automatically transferred to the off position by the known current and voltage-dependent triggers.

A top view of the lower part 4 is shown in FIG. 2. Corresponding to the design of the switch 1 as a three-pole circuit breaker, the lower part 4 has a left outer wall 20 and a right outer wall 21 as well as two partition walls 22 and 23, the three adjacent chambers 24 for the pole tracks of the Disconnect the switch. Screw holes 18 and 19 for connecting the upper part 3 to the lower part 4 are provided in the partition walls near the upper and lower ends of the housing.

The partitions 22 and 23 are continuously stepped at right angles, thereby forming inner lower parts 22a and 23a and raised parts 22b and 23b. The screw holes 18 and 19 open half in the deeper parts 22a and 23a and half on island-like elevations 22c and 23c, respectively, which extend to the height of the raised parts 22b and 23b. On the upper and lower end faces of the housing 2, the partitions 22 and 23 each end in two ribs 22d and 22e or 23d and 23e. These ribs serve to extend the creepage distance between the adjacent connecting terminals 5 and 12. The dividing walls 22 and 23 are each provided with a recess 25 and 26 for mounting the selector shaft 14. The bottom of these recesses forms a lower bearing shell 27 or 28. The selector shaft 14 engages with a disk-shaped rib 30 (FIG. 5) in a groove 31 or 32 of each bearing shell 27 or 28, which also results in the bearing of the selector shaft gradation is achieved. Furthermore, there are further grooves on the sides of the recesses in the partition walls 22 and 23 33 and 34, respectively, into which insert pieces provided with corresponding ribs 36 can be inserted (FIG. 5). The insert 35 shown has a groove 37 corresponding to the grooves 31 and 32 and a bearing surface 38 for the selector shaft 14.

The outer walls 20 and 21 are also stepped at right angles and therefore have lower parts 20a and 21a and raised parts 20b and 21b. The raised parts of the outer walls are interrupted in places where the outer walls 20 and 21 are provided with recesses in the form of grooves 40 and 41, respectively. These grooves serve as line channels for leading auxiliary lines out of the housing 2 in such a way that the lines do not enlarge the width of the housing. The circuit breakers can therefore be installed directly adjacent to each other even when auxiliary lines are connected.

The upper part 3 (Fig. 3 and 4) also has outer walls 50 and 51 and partitions 52 and 53. These walls are continuously graduated at right angles, so that when the upper part 3 is placed on the lower part 4 there is a stepwise overlap of the walls almost everywhere. For this purpose, the lower parts 52a and 53a are provided on the outside of the partitions and the raised parts 52b and 53b on the inside of the partitions 52 and 53. At the point where the recesses 25 and 26 are in the partitions 22 and 23 of the lower part 4, the partitions 52 and 53 of the upper part 3 are continuous. They interact with the inserts 35 at these points. The partitions 52 and 53 of the upper part 3, however, are provided at another point with recesses 54 and 55 for the passage of a trigger shaft. By a staged design of the recesses 54 and 55 and the trigger shaft is also provided here for a seal against the passage of switching gases and for the extension of the creepage distance.

At the upper and lower ends of the partitions 52 and 53, screw holes 56 and 57 are provided which are aligned with the screw holes 18 and 19 of the lower part. In the area of these screw holes, the raised part 52b of the partition 52 and the raised part 53b of the partition 53 are forked. One fork arm 52c or 53c extends to the front end of the upper part 3, while the other fork arm 52d or 53d is shorter. Between the two fork arms there is a space for receiving the island-like elevations 22c and 23c of the dividing walls 22 and 23 of the lower part 4. Just as in the lower part 4, the screw holes 56 and 57 of the upper part 3 each open approximately at the level of the lower parts 52a and 53a of the partitions 52 and 53 and on the raised parts, i.e. H. the shorter fork arms 52d and 53d. These fork arms thus form part of the wall of the screw holes.

The outer walls 50 and 51 of the upper part 3 are stepped over their entire length and accordingly have inner lower parts 50a and 51a and raised parts 50b and 51b.

Lateral projections 60 and 61 are provided near the upper ends of the raised parts 50b and 51b of the upper part 3, which cooperate with corresponding lateral recesses 62 and 63 of the raised parts 20b and 21b of the lower part 4. These projections and recesses are arranged and dimensioned so that they the relative position of the upper part 3 to the lower part 4 in Determine the longitudinal direction of the housing 2 and that a power transmission can take place at these points. The remaining projections and recesses, e.g. B. the projections for the ejector pins 64 and 65 of the partitions 52 and 53 and the recesses 66 and 67 of the partitions 22 and 23 of the lower part 4 are dimensioned so that they interlock with play and thus the through the projections 60 and 61 and the recesses 62 and 63 did not affect the dimensionally accurate fixing of the housing parts.

The grooves 40 and 41 of the lower part 4 are covered by the raised parts 50b and 51b of the upper part 3 when the housing parts are joined together (FIG. 1). This leads to a deflection of escaping gases in the longitudinal direction of the grooves 40 and 41, i. H. to a gas flow running essentially parallel to the outer walls of the lower part 4. A gas leak is further restricted if the grooves 40 and 41 are provided with auxiliary lines as intended and the associated auxiliary devices are arranged in the interior of the housing 2. The interruption of the step overlap in the region of the raised parts of the outer walls of the lower part 4 therefore has no disadvantageous effect when two or more switches are installed close together.

A further exemplary embodiment of a housing is shown in FIGS. 6 and 7 with the aid of a lower part, which is shown about half each, and an upper part of another housing. The lower part 70 also has three parallel chambers 71 for the pole tracks of the switch. The outer walls 72 and 73 are provided with outer lower parts 72a and 73a and inner raised parts 72b and 73b. The raised parts are interrupted only in the area of grooves 74 of the outer wall 72 and of grooves 75 and 76 of the outer wall 73 to the level of the deeper parts 72a and 73a. The grooves of the outer wall 72 are offset from the grooves of the outer wall 73 in such a way that the step overlap of the outer walls between immediately adjacent switches is never interrupted.

The partition walls have einander'zugewandte 77 and 78, low-lying parts 77a and 78a, into which S _c hrau- holes are closed 80 and 81 open. In the area of the screw holes, the raised parts 77b and 78b are opposed by a further raised part 77c and 78c on each partition, which, like the raised parts 77b and 78b, extends to the front end of the lower part 70.

The associated upper part 85 (FIG. 7) has partition walls 86 and 87, the raised parts 86b and 87b of which are designed with thickened regions 86c and 87c in the region of the screw holes 90 and 91, which are aligned with the screw holes 80 and 81 of the lower part 70, which enclose the screw holes. The thickened areas are received between the raised parts 77b and 77c and 78b and 78c when the upper part 85 is placed on the lower part 70. Immediately following these thickened regions 86c and 87c, there are lateral rectangular recesses 92 and 93, with which corresponding lateral projections 94 and 95 of the lower part 70 cooperate. In the manner already described, the projections and the recesses determine the relative position of the upper part 85 and the lower part 70 in the longitudinal direction and enable a force transmission in the longitudinal direction.

On the raised parts 86b and 87b of the upper part 85, slot-like recesses 96 and 97 are provided in the region of the insert pieces, not shown, for supporting the selector shaft, which extend below the level of the lower parts 86a and 87a of the partition walls 86 and 87. These recesses serve to receive corresponding ribs of the insert pieces in order to achieve a further labyrinth-like nesting of the parts than can be achieved by the right-angled gradation of the walls.

As can be seen from the above description of two exemplary embodiments, on all partition walls and outer walls of the housing, as a result of the step overlap - apart from minor local interruptions on the outer walls of the lower parts - a nesting is achieved which causes switching gases to pass into adjacent pole tracks of the same or an adjacent switch also prevented by detours. At the same time, the creepage distances are considerably extended everywhere. Where components connecting the adjacent pole tracks are present, e.g. B. a control shaft or a trigger shaft, ensure that the dividing walls and these components also interleave interacting insert pieces for sealing and extending the creepage distances. The stepped design of the partition walls and the outer walls is also used in the longitudinal direction by incorporating lateral projections and recesses for securing the position and transmitting power between the housing parts.

Claims (7)

1. Low-voltage circuit breaker with an insulating material housing divided along a parting joint into an upper part and a lower part and with mutually overlapping partition walls between the pole tracks of the switch, characterized in that the partition walls (22, 23, 50, 51) of the upper part (3) and of the lower part (4) overlap one another over their entire length and that the outer walls (20, 21, 52, 53) of both housing parts (3, 4) overlap one another over substantially their entire length. 2. Low-voltage circuit breaker according to claim 1, characterized in that interruptions (74, 75, 76) of the overlap in the region of the two outer walls (72, 73) are arranged offset from one another. 3. Low-voltage circuit breaker according to claim 1, characterized in that the raised parts (52b, 53b) of the partitions (52, 53) of a housing part (3) in the region of screw holes (56, 57) forked (52c, 53c, 52d, 53d) and one fork arm (52d, 53d) forms part of the wall of a screw hole (18, 19). 4. Low-voltage circuit breaker according to claim 1, characterized in that the screw holes (90, 91) in the raised part (86b, 87b) of the partitions (86, 87) of a housing part (85) are completely included and that the screw holes containing area (86c, 87c) between the raised part (77b, 78b) of the partitions (77, 78) of the other housing part (70) and an additional raised part (77c, 78c). 5. Low-voltage circuit breaker according to claim 1, characterized in that the partitions (22, 23) in the region of adjacent pole tracks connecting components (14) have stepped recesses (25, 31; 26, 32) and that in the recesses Components (14, 30) cross-insert pieces (35) are inserted. 6. Low-voltage circuit breaker according to claim 1, characterized in that the partition or outer walls (20, 21, 22, 23) of the upper and lower part (3, 4) of the insulating housing (2) near one of the front ends with a projection or a recess (60, 61, 62, 63) intermesh precisely and that all other projections and recesses (64, 65, 66, 67) in the course of the outer walls (20, 21) and the partitions (22, 23) engage both parts of the housing (3, 4) with play. 7. Low-voltage circuit breaker according to claims 4 and 6, characterized in that the projections and recesses (92, 93, 94, 95) are arranged close to the screw holes (80, 81, 90 91).

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