FR2663458A1 - MINIATURE ELECTRIC CIRCUIT BREAKER WITH CUTTING GAS EXHAUST. - Google Patents

Abstract

An electrical circuit breaker (10) with an insulating box (12) encloses a main arc extinguishing chamber (26), and a decompression chamber (40) communicating with the external environment through an evacuation orifice (42). According to the invention, the discharge orifice (42) is formed in the rear face (18) of the insulating housing (12), to divert the ionized gas flow from the side of the fixing base (20) towards an area without connecting conductors or live conductive parts.

Description

MINIATURE ELECTRIC CIRCUIT BREAKER WITH GAS EXHAUST

CUT.

  The invention relates to a miniature electric circuit breaker with molded insulating housing of parallelepiped shape having a handle projecting from a front face, a fixing base arranged on an opposite rear face, and a pair of narrow lateral connection faces, said case containing a main arc extinguishing chamber with deionization plates, and a decompression chamber communicating the output of the main chamber with the medium

  outside through a discharge opening.

  In the circuit breakers of the prior art, the exhaust of the breaking gases towards the external environment is generally effected by means of an orifice arranged in the narrow lateral face of the housing, that is to say in the environment in which there is the connection conductor In the event of a short-circuit current cut, the lateral orientation of the ionised gas exhaust may cause priming with the connection conductor The presence of flame arresters in the orifice evacuation helps to cool the ionized gases before they escape to the outside environment.

  cooling nevertheless depends on the structure of the

  flames The use of simple metallic deionization grids does not allow optimum cooling of the ionized gases to be obtained, and the risk of external ignition remains for high currents The use of special deionization boxes makes it possible to improve cooling, but their incorporation into the discharge port is

  incompatible with the dimensions of the miniature circuit breaker.

  The object of the invention is to improve the exhaust

  cut-off gases from a miniature circuit breaker.

  The circuit breaker according to the invention is characterized in that the evacuation orifice is provided in the rear face of the insulating housing, in order to divert the ionized gas flow from the side of the mounting base, to an area devoid of conductors

  connection or live parts under tension.

  The exhaust of the gases is deflected 90 degrees relative to the circuit breakers of the prior art, thanks to the positioning of

  the discharge opening in the rear face of the housing.

  This modification of the gas exhaust avoids any priming

  outside regardless of the intensity of the current to be interrupted.

  Other advantages and features will emerge more

  clearly from the following description of a mode of

  embodiment of the invention, given by way of nonlimiting example, and represented in the appended drawing, in which: FIG. 1 is a schematic elevation view of the circuit breaker according to the invention, with a partial section at the level of the exhaust the arc extinguishing chamber; Figure 2 shows a sectional view along line II-II of

Figure 1.

  In the figures, a miniature circuit breaker 10 with an insulating casing 12 molded in a parallelepiped shape, has a front face 14 from which protrudes a lever 16 of the mechanism, an opposite rear face 18 equipped with a mounting base 20, and a pair 22.24 narrow side faces of connection The main arc extinguishing chamber 26 is formed by a stack of deionization sheets extending parallel to the base 20 The outlet 28 of the arc extinguishing chamber 26 is positioned against a perforated wall 30 authorizing the passage of gas from

  cut during the arc extinction phase.

  A connection conductor 32 is introduced on the side of the face 22 into a cage of a connection terminal 34, which is housed in a cell 36 of the housing 12 The base 20 for fixing the circuit breaker 10 can be adapted on a mounting rail (not shown). A partition 38 of subdivision of the housing 12 is formed between the cell 36 and the perforated wall 30 to confine a decompression chamber 40 at the outlet 28 of the extinguishing chamber 26 The decompression chamber 40 is closed on the side of the face side 22, so as to prevent any escape of ionized gases from the side of the connecting conductor 32 An orifice 42 for evacuation is provided in the rear face 18 of the housing 12, authorizing the communication of the decompression chamber 40

with the outside environment.

  During the arc extinction phase in the main chamber 26, the breaking gases are directed towards the decompression chamber 40, and are evacuated through the orifice 42 towards the outside environment, after passing through a baffle 44 (see arrow direction F) The presence of the discharge orifice 42 in the rear face 18 of the insulating housing 12 makes it possible to divert the ionized gas flow from the side of the base 20, towards a posterior zone, devoid of

live parts under voltage.

Claims (3)

  1 miniature electric circuit breaker with insulated housing (12) of parallelepiped shape having a lever (16) projecting from a front face (14), a mounting base (20) arranged on an opposite rear face (18), and a pair of narrow side faces (22,24) for connection, said housing containing a main chamber (26) for extinguishing arcs with deionization plates, and a decompression chamber (40) communicating the outlet (28) of the main chamber (26) with the external medium through an evacuation orifice (42), characterized in that the evacuation orifice (42) is formed in the rear face (18) of the insulating housing (12), for divert the ionized gas flow from the side of the mounting base (20) to an area devoid of connecting conductors or live conductive parts.   2 Circuit breaker according to claim 1, characterized in that the decompression chamber (40) comprises a baffle (44) located   in the vicinity of the discharge orifice (42).   3 Circuit breaker according to claim 1 or 2, characterized in that the outlet (28) of the main arc extinguishing chamber (26) is positioned against a perforated wall (30) of the housing (12), and that a partition (38) of subdivision separates the decompression chamber (40) from a cell (36) housing a terminal connection (34).