DE9305177U1 - Lower part of a molded housing of a multi-pole low-voltage switching device divided into parallel chambers - Google Patents

Description

Lower part of a molded housing divided into parallel chambers of a multipole low-voltage switchgear

The invention relates to multi-pole low-voltage switching devices, in particular circuit breakers, with a molded housing consisting of a lower part and an upper part made of injection-moldable plastic. In particular, it relates to a lower part divided into parallel chambers by longitudinal walls, in which chambers connection devices, fixed and movable contacts, arc extinguishing devices and connecting current paths are arranged.

According to EP 206 249 B1, a housing base of this type is known in which a thin separating plate is arranged at right angles to the longitudinal walls of the chamber between the arc extinguishing device and the movement apparatus of the contact system. The separating plate is made of glass fiber reinforced polyester or the like, contains a central, elongated rectangular opening for the movable contact arm and is indirectly attached to the housing base. Apparently previously used circuit breakers from Siemens AG (e.g. type 3VF3) contain flexible plastic separating films attached to the arc extinguishing devices, which are provided with a vertical slot for the movable contact arms. The known separating plates or foils reduce the contamination of the musculoskeletal system and other switch devices, such as the switch lock, by the dirt particles that occur during a short circuit by spatially separating the relevant switching chamber areas and create more defined pressure conditions that ensure better discharge of the arc gas to the outside. However, this purpose is achieved at the cost of high manufacturing and assembly costs for the separating plates or foils.

The aim of the invention is therefore to provide a simple way of spatially separating the arc extinguishing areas from the rest of the chamber area.

Klöckner-Moeller GmbH

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01.04.1993 0 288 GM

Starting from a lower part of the type mentioned at the outset, the object is solved according to the invention by the characterizing features of claim 1. While retaining the advantages of the previously known solutions, the advantage of the transverse wall according to the invention is a considerable reduction in the effort involved in producing the lower part and in assembling the low-voltage switchgear, since separating plates or foils do not have to be manufactured or installed separately. An additional advantage is that a molded housing that is provided with such a lower part manufactured without additional work steps for the transverse wall has a significantly higher rigidity and thus better dimensional stability.

Further advantageous embodiments of the lower part according to the invention can be found in the dependent claims. The presence of the transverse wall allows the attachment of guide elements to facilitate the assembly of the switch lock and to further increase its positional stability. The transverse wall can also be used advantageously by appropriate shaping in such a way that the U-shaped part of the fixed contact carrier is covered by the transverse wall to such an extent that, on the one hand, this U-shaped part can come into electrodynamic operative connection with as large an area of the movable contact arm as possible in order to make full use of the electrodynamic effect when a short circuit occurs, but, on the other hand, the switching chamber areas are largely separated from the movement apparatus and the switch lock.

The invention will be explained in more detail below using an embodiment from which further details and advantages can be seen. In the accompanying drawing,

Figure 1: the top view of a lower part according to the invention;

Figure 2: the perspective view after a longitudinal section along the line H-II according to Fig. 1.

In Fig. 1 and Fig. 2, the lower part 2 of a molded housing, produced in a single injection molding, of a known type for a three-pole circuit breaker is shown as an example of a low-voltage switching device.

The lower part 2 has a bottom 3 and is separated by two outer longitudinal walls

Klöckner-Moeller GmbH

01.04.1993 0 288 GM

4 and 6 and divided into three parallel chambers 12, 14 and 16 by two inner longitudinal walls 8 and 10. In the direction of the connection sides 18 and 20, the chambers 12, 14, 16 are each delimited by an end wall 22 or 24, which extends to the longitudinal walls 4, 6.
5

The lower part 2 is shown only partially equipped with a movement apparatus 26 in the form of a switch shaft mounted transversely between the longitudinal walls 4, 6 and in the area of the middle chamber 14 with a fixed contact carrier 28, a movable contact arm 30 and a current path 32. The contact carrier 28 mounted on the base 3 merges into a first connection path 34 on the one hand and carries a fixed contact piece 40 on its U-shaped bent part 38 on the other. The contact arm 30 is connected to the movement apparatus 26 on the one hand and carries a movable contact piece 42 on the other hand, which can be brought into and out of connection with the fixed contact piece 40. The current path 32 mounted on the base 3 serves to connect a second connection path 36 to a triggering device (not shown). An arc extinguishing device (not shown) is to be arranged in the area of the contact pieces 40, 42. When the lower part is fully equipped, the areas of the two outer chambers 14, 16 are provided in the same way with contact carriers, contact arms, current paths and arc extinguishing devices.

A transverse wall 44 arranged parallel to the end walls 22, 24 runs continuously from one longitudinal wall 4 to the other longitudinal wall 6. The transverse wall 44 divides the chambers 12, 14, 16 into first chamber areas 12A, 14A, 16A and second chamber areas 12B, 14B, 16B. The first chamber areas 12A, 14A, 16A accommodate the arc extinguishing devices, the contact carriers 28 and the part of the contact arms 30 having the movable contact piece 42. The second chamber areas 12B, 14B, 16B accommodate the movement apparatus 26 with the part of the contact arms 30 mounted thereon, the current paths 32 and the thermal and magnetic triggering elements. The transverse wall 44 has a rectangular, slot-like vertical recess 46 in each chamber 12, 14, 16, through which the associated contact arm 30 reaches and which is dimensioned such that the contact arm 30 is not hindered in its movement to close and open the contacts 40, 42, taking all tolerances into account. This ensures the greatest possible insulation of the

Klöckner-Moeller GmbH

01.04.1993 0 288 GM

second chamber areas 12B, 14B, 16B from the first chamber areas 12A, 14A, 16A.

The second chamber area 14B of the middle chamber 14 also has to accommodate a switch lock (not shown). To facilitate its installation in the lower part 2 and to better hold it in the lower part 2, a guide element 48 in the form of a groove is formed in the middle and upper area of the transverse wall 44.

The magnetic field that builds up between the U-shaped part 38 of the contact carrier 28 and the contact arm 30 tears the contact arm 30 away from the fixed contact piece 40 when a very high short-circuit current occurs due to the electrodynamic forces that occur. The area 50 of the transverse wall 44 near the bottom is L-shaped in such a way that it grips a large part of the U-shaped part 38 from behind. The transverse wall 44 is thus designed in such a way that it also holds the contact carrier 28 with its area 50 near the bottom, so that there is enough space in the second chamber areas 12B, 14B, 16B and that the electrodynamic effect is not impaired.

Claims (1)

Protection claims Lower part of a molded housing of a multi-pole low-voltage switching device, in particular a circuit breaker, which is divided into parallel chambers and is to be closed off at the top by an upper part, has delimiting or dividing longitudinal walls (4; 6; 8; 10) and contains in each of the chambers (12; 14; 16) a fixed contact carrier (28), a movable contact arm (30), an associated part of a movement apparatus (26), current paths (32) connecting to connection and other devices, and an arc quenching device, characterized in that a continuous transverse wall (44) which is integrally connected to the longitudinal walls (4; 6; 8; 10) and to the base (3) of the lower part (2) is arranged directly in front of the first chamber regions (12A; 14A; 16A) containing the arc quenching devices, and separates these from the second chamber regions (12B; 14B; 16B) and that the transverse wall (44) has narrow, substantially rectangular vertical recesses (46) for the contact arms (30) to reach through. Lower part according to claim 1, characterized in that the transverse wall (44) has guide elements (48) in its upper central region for the assembly of a switching lock. 3. Lower part according to claim 1 or 2, characterized in that the transverse wall (44) in its area near the floor (50) is designed to engage behind the cover of a part (38) of the fixed contact carrier (28) which is bent in a U-shape and points towards the musculoskeletal system (26).