RU2505876C2 - Low-voltage switch - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: low-voltage switch has a housing which holds at least one fixed contact and a movable contact which is engaged and disengaged with the fixed contact, a drive mechanism operably connected to the movable contact, at least first and second terminals electrically connected to the fixed contact and the movable contact, respectively, and an arc chamber placed between the fixed contact and a conducting element, having a first end which is electrically connected to the second terminal and a second end which ends with the lower side. The arc chamber has multiple moulded conducting plates which are inserted between the fixed contact and the second end of the conducting element, and a main part having a second insulating housing which holds an element made of ferromagnetic material. The main part is placed adjacent to the multiple moulded conducting plates and defines the space for passage of the movable contact as it moves between the closed position and the open position.

EFFECT: making a switch which, with a relatively simple design, provides highly effective cutting of overload current owing to sufficient rate of opening and control of the electric arc.

11 cl, 4 dwg

Description

Technical field

The present invention relates to a low voltage circuit breaker, for example for domestic use.

State of the art

It is known that low-voltage circuit breakers usually contain a housing containing one or more poles, each of which is connected to at least one pair of contacts mutually coupled and tripped to each other. The switches of the prior art also comprise a control means which causes the relative movement of the pairs of contacts in such a way that they allow at least a first clutch position (closed circuit) and a second disengagement position (open circuit).

In general, pairs of mutually interlocking / tripping contacts are composed of first elements that are essentially fixed (fixed contacts) and second movable elements (moving contacts). Instead, the control means comprises drive mechanisms that end, for example, with a drive main shaft operably connected to the movable contacts.

In addition, at least one arc chamber is generally connected to each pole of the switch, that is, to a region of space, in particular adapted to facilitate interruption of the electric arc. Arc chambers can be simple areas created in the circuit breaker case, or they can contain various modular elements, for example, structured as cases made of dielectric material provided with arcing plate plates.

As is already known, during the period of normal operation of the circuit breaker, processes can occur that expose the circuit breaker and network to extremely heavy loads. This occurs, first of all, if the circuit breaker is required to withstand, even for short periods, electric currents that are greater than the rated current. The time during which the circuit breaker and the mains are exposed to an overload current (i.e., an overload or a short circuit) generally depends on the time required by the protection devices to effect a safe trip, that is, to interrupt the overload current.

As is already known, in order to limit the occurrence of damage, both of the electric network and of the circuit breaker as such or its parts (contact plates, arcing chamber, control, dielectric elements), many methods were tested and introduced to create as quick and efficient opening as possible . Various solutions include, for example, the use of appropriate control springs and materials suitable to withstand heavy loads and temperatures.

Other solutions include the use of gasification means and / or materials capable of releasing extinguishing agents near the area in which the electric arc is formed; these means and / or materials are typically triggered by the temperature reached when an electric arc occurs.

Also, other solutions tend to create effective use or control in various ways of electromagnetic processes that occur in the field of formation and interruption of the electric arc.

Solutions of this type, despite their relative effectiveness from a functional point of view, present one or more disadvantages associated with structural complexity and / or insufficient opening speed and / or insufficient control of the electric arc phenomenon.

Summary of the invention

Therefore, the main objective of the present invention is to provide a switch, in particular, a low voltage switch, which overcomes the above-mentioned disadvantages.

Within the scope of this task, an object of the present invention is a circuit breaker, in particular a low voltage circuit breaker, which combines a relatively simple structure with high efficiency in terms of opening speed and controlling the occurrence of an electric arc.

Another object of the present invention is to provide a circuit breaker, in particular a low-voltage circuit breaker, in which the wear processes caused by the electric arc, in particular in the movable contact, are minimized.

An additional object of the present invention is the provision of a switch, in particular a low voltage switch, in which the opening speed of the movable contact is high.

Not the least important task of the present invention is to provide a circuit breaker, in particular a low voltage circuit breaker, which is highly reliable and relatively easy to manufacture at competitive prices.

Therefore, an object of the present invention is a low voltage switch comprising: a first housing accommodating: at least one fixed contact and a corresponding movable contact, coupled and disengaged with the fixed contact between the first closed position and the second open position; a drive mechanism operably associated with a movable contact; at least the first and second terminals are electrically connected respectively to a fixed contact and to a movable contact; arc chamber. The switch, in accordance with the invention, is characterized in that the arc chamber is installed between the fixed contact and the conductive element, the first end of which is electrically connected to the second terminal, and the second end ends with the lower side, and the arc chamber contains many molded conductive plates inserted between the fixed contact and the second end of the conductive element, the switch, characterized in that the main part containing a second insulating housing that accommodates the element made and c ferromagnetic material, is installed next to many molded conductive plates, and the main part determines the space for the passage of the movable contact during its movement between the aforementioned first closed position and the second open position.

Thus, in accordance with the mechanisms that will be more fully described below, the opening speed of the circuit breaker (i.e., the speed with which the movable contact moves from the first closed position to the second open position) increases due to electromagnetic effects generated by an element made of ferromagnetic material (like effects generated by poles). In addition, the concrete installation of the arc chamber between the fixed contact and the conductive element provides the preferred path for the electric arc, moving it from the movable contact and, thus, limiting its potential damage.

Preferably, the molded conductive plates are substantially mutually parallel; in particular, the molded conductive plates are preferably a substantially rectangular surface, with a first main side and a second upper side facing the first side, with a recess made in the upper side, the lower points of the recesses of each molded conductive plate lying in one and the same plane, orthogonal to the planes in which the conductive plates lie. Even more preferably, the lower points of the recesses of each molded conductive plate are connected by a dashed line.

Preferably, the molded conductive plates comprise a first plurality of molded conductive plates, the main sides of which lie in the same lower plane, and a second plurality of molded conductive plates, whose lower sides are scaled relative to the lower plane in the direction of the main side of the second end of the conductive element. More preferably, the upper sides of the molded conductive plates of the first plurality of plates lie in the same upper plane parallel to the lower plane, and the upper sides of the molded conductive plates of the second plurality of plates are scaled relative to the upper plane in the direction of the lower side of the second end of the conductive element. Thus, the removal of the electric arc from the movable contact is greatly simplified.

Preferably, a base for mounting the arc chamber is defined in the first housing, the base having a base wall with a first surface adjacent to the fixed contact and a second surface adjacent to the first surface and inclined with respect to it in the direction of the lower side of the second end of the conductive element.

Preferably, at least one channel is defined in the first housing, which is located inside the housing and connected to the external part, with the inlet section of the channel adjacent to the second end of the conductive element.

Preferably, the main part comprising an element made of a ferromagnetic material is substantially U-shaped, with mutually parallel first and second arms connected by a third arm perpendicular to them, with a space for passing a movable contact defined between the first and second arms , and being open in the direction of fixed contact, while the third arm is opposite the conductive element. Preferably, the main part comprising an element made of a ferromagnetic material is a support surface for supporting at least some of the molded conductive plates on the upper side, the support surfaces being a protrusion suitable for being inserted into a space defined by recesses made in the upper sides of the molded conductive plates.

Preferably, the movable contact in the first closed position is located in a position that is closest relative to the plurality of molded conductive plates and relatively stationary contact, and in the second open position is located in a position allocated relative to the plurality of molded conductive plates and relatively stationary contact. In other words, in accordance with this embodiment, the movable contact when moving between the first closed position and the second open position, tends to move both from the movable contact and from the molded conductive plates of the arc chamber, reducing the risk of providing a preferred path for the electric arcs.

Additional characteristics and advantages of the present invention will be more apparent from the description of preferred, but not exclusive, embodiments of the present invention, depicted by way of non-limiting example in the accompanying drawings.

Brief Description of the Drawings

The invention is further explained in the description of the preferred embodiments with reference to the accompanying drawings, in which:

Figure 1 depicts a General view in section of part of a low voltage switch in accordance with the present invention;

Figure 2 depicts a General view of the components of the arc chamber of the switch of Figure 1;

Figure 3 depicts in more detail a General view of the components in figure 2;

Figure 4 depicts in more detail a General view of the components in Figure 3.

DESCRIPTION OF PREFERRED EMBODIMENTS

Below, with reference to the accompanying drawings will be described an embodiment of a low voltage switch 1 in accordance with the invention.

As shown in FIG. 1, the switch 1 comprises a first housing 10 in which at least one fixed contact 20 and its corresponding movable contact (not shown) are mounted, coupled and disengaged with the fixed contact 20 between the first closed position and the second open position, and a drive mechanism (not shown) operably connected to the movable contact. The drive mechanism may be of the type commonly used in this application, and therefore will not be described in detail below.

In addition, at least a first terminal (not shown) is electrically connected to the fixed contact 20, for example, via the terminal 21 of the fixed contact 20, and a second terminal 30 electrically connected to the movable contact.

One of the specific parameters of the switch 1 in accordance with the invention is that it comprises an arc chamber 40, which is installed between the fixed contact 20 and the conductive element 50 (element guiding the arc) having a first end 51 connected by electrical connection to the second terminal 30 and a second end 52 ending in the lower side 53. As will be more apparent below, the conductive element 50 forms a preferred circuit element for an electric arc, preventing the arc from closing on a movable contact ie during the opening stage.

The arc chamber 40 comprises a plurality of molded conductive plates 41 which are inserted between the fixed contact 20 and the second end 52 of the conductive element 50. The switch 1, in accordance with the present invention, also constitutes a main part 60 comprising a second insulating body 61 that accommodates the poles, made of ferromagnetic material (not shown, as they are enclosed in a housing 61). The main body 60 is mounted adjacent to the plurality of molded conductive plates 41 and defines a space 65 for the movable contact to pass during its movement between the first closed position and the second open position.

In practice, the movable contact during its movement between the closed position and the open position (and vice versa) moves in space 65. In the conditions of circuit closure or in the presence of an electric arc, the electromagnetic effect due to the electric current flowing in the circuit and the presence of poles (ferromagnetic element of the main part 60) attracts the movable contact to the open position, thereby contributing to the acceleration of the opening operation.

As shown in FIGS. 3 and 4, the molded conductive plates 41 are preferably substantially mutually parallel. More preferably, in accordance with the depicted embodiment, the molded conductive plates 41 are essentially a quadrangular plane with a first main side 411 and a second upper side 412, which is opposite the first side 411. The recess 413, which in the embodiment shown in the drawing is essentially V-shaped, preferably made in the upper side 412.

The configuration of the recesses 413 in the conductive plates of various shapes 41 is such that, preferably, the lower point 414 of the recesses 413 of each molded conductive plate 41 lies in the same orthogonal plane on which the molded conductive plates 41 lie. In other words, in the case when the recesses 413 are V-shaped, all the lower vertices of the V-shaped recesses, regardless of the opening and the depth of the recess, lie in the same plane, which is orthogonal to the plane in which the plates 41 lie.

As shown in FIGS. 1 and 2, the insertion of the plates and / or the depth of the recesses are preferably such that all the lower points 414 of the recesses 413 of each molded conductive plate 41 are not in a straight line, but are connected by a dashed line. As can be seen from the accompanying drawings, this dashed line is downward, in the sense that, at least from a certain point in the forward direction, the lower points 414 of the recesses 413 are located further along the first direction (the distance corresponding to the step with which molded conductive plates 41) are installed, and are located further along the second direction, orthogonal to the first direction.

This can be achieved by changing the depth of the recesses 413 and / or the relative position of the molded conductive plates 41. As shown in the accompanying drawings, in this latter case, in particular preferred, the molded conductive plates 41 comprise a first plurality of molded conductive plates 41a, main sides 411 which lie in the same main plane, and the second set of molded conductive plates 41b, the main sides 411 of which are scaled relative to the main plane in the direction of the lower side 53 of the second end 52 of the conductive element 50. Preferably, the upper sides 412 of the molded conductive plates of the first plurality of plates 41a also lie on the same upper plate parallel to the main plate, while the upper sides 412 of the molded conductive plates of the second plurality the plates 41b are proportional to the upper plane in the direction of the lower side 53 of the second end 52 of the conductive element 50.

From a practical point of view, this can be achieved by using molded conductive plates (identical in size to each other) for the first plurality of plates 41a, which are installed in turn with the same mutual arrangement, and for the second set of molded conductive plates 41b, installed with a constant pitch , but at different heights, that is, located on a scale along the same direction.

For example, as shown in the accompanying drawings, starting from the position closest to the fixed contact 20, the first sub-set of plates 41 (for example, the first three plates 41) of the first plurality of plates 41a has the same size and shape (including the size and shape of the recess 413). It is followed by a second sub-set of plates 41 (that is, of the next four plates 41) of the first plurality of plates 41a, which are of the same size but different shape, that is, with more and more deep recesses 413. Finally, they are followed wafers from a second plurality of wafers 41b (e.g., three wafers) that are located at different heights, that is, are scaled with respect to the distance closer to the lower side 53 from the second end 52 of the conductive element 50.

Thus, starting from the movable contact 20, the space in the molded conductive plates 41 defined by the recess 413 is more and more bent towards the lower side 53 from the second end 52 of the conductive element 50. In fact, as can be seen from FIG. 1 and 2, the movable contact 20 and the end part (lower side 53) of the second end 52 of the conductive element 50 are mounted at different heights relative to the transverse view of the switch 1. This greatly contributes to providing the preferred path for the electric arc, preventing it from closing on the movable contact with subsequent problems its wear and tear.

Traditionally, the plates 41 are pre-assembled together through their laying between the first 45 and the second 46 insulating plates provided by the first connection means (e.g., holes) allowing connection with the corresponding second connection means (e.g., protrusions) mounted opposite the side borders of the molded conductive plates 41. However, other types of assembly are also possible.

As shown in FIG. 1, the space for receiving the arc chamber 40 is preferably defined in the first housing 10, a space representing the bottom wall with the first surface (not visible, since it is hidden by the insulating plate 45) adjacent to the fixed contact and the second surface 12 adjacent to the first surface and inclined relative to the direction of the lower side 53 from the second end 52 of the conductive element 50. This provides a preferred and convenient installation of the molded conductive plates 41 in the base ear.

In addition, in the first housing 10, at least one channel 15 is preferably marked connecting the interior of the housing with the external side, the inlet section 16 of the channel 15 located next to the second end 52 of the conductive element 50. Thus, the gases that propagate after the occurrence of electric arcs are easily released outside the housing 10, reducing the risk of damage to the circuit breaker 1, and devices located in the housing 10.

As shown in FIG. 3, the main body 60 is preferably substantially U-shaped, with mutually parallel first 63 and second 62 arms connected by a third arm 64 perpendicular to them. Therefore, in this housing, a space 65 for passing a movable contact is designated between the aforementioned first 63 and second 62 arms is open in the direction of the fixed contact 20, while the third arm 64 is opposite the conductive element 50.

In addition, the main body 60 is preferably a support surface 66 for supporting, on the upper side 412, at least several molded conductive plates 41; the supporting surface 66 is traditionally a protruding part 67, suitable for insertion into the space defined by the recess 413, made in the upper sides 412 of the molded conductive plates 41.

In fact, it was experimentally discovered that this structure, in particular, is effective in terms of the opening speed of the movable contact, due to the electromagnetic effects previously described.

From the point of view of operation, the movable contact in the first closing position is located in the position that is closest, both with respect to the plurality of molded conductive plates 41, and with respect to the fixed contact 20, while in the second opening position it is located in a position remote both a plurality of molded conductive plates 41, and with respect to the aforementioned fixed contact 20. In other words, during displacement for opening (i.e., passing from the first closing position to the second opening position), the movable contact moves both from the stationary contact 20 and from the plurality of molded conductive plates, essentially in accordance with the direction of the arrow 100 of FIG. 1. Since the specific structure of the arc chamber (shape, size and installation of the molded conductive plates 41) and the mutual installation of the fixed contact 20 and the second end 52 of the conductive element 50 tend to conduct an electric arc in the opposite direction to the direction of the arrow 100, the risks of electrical short circuiting are further reduced. arcs on a moving contact.

As can be seen from the above description, the low-voltage circuit breaker in accordance with the present invention fully achieves the intended purpose and objectives.

In particular, the presence of the main part 60 containing the ferromagnetic element, allows you to accelerate the movement to open the contacts. The risks of arc closure on a movable contact, and its successively increasing or immediate damage, are minimized by the structure of the arc chamber 40 and by the shape and installation of its components.

It should also be emphasized that the system is essentially composed of a series of sub-kits (main body 60; molded conductive plates 41 and insulating plates 45 and 46; fixed contact 20 and movable contact; conductive element 50), which are relatively simple to manufacture and installation.

Based on the description provided, other parameters, modifications or improvements are possible and obvious to those skilled in the art. Therefore, these parameters, modifications and enhancements should be considered part of this model. In practice, any materials used and proportional sizes and shapes can be applied in accordance with the requirements and current level of technology.

Claims (11)

1. A low-voltage switch (1) comprising a first housing (10) in which at least one fixed contact (20) and a corresponding movable contact, coupled and uncoupled with a fixed contact (20) between the first closed position and the second are placed open position, a drive mechanism operably connected to the movable contact, at least the first and second (30) terminals, respectively electrically connected to the fixed contact (20) and to the movable contact, the arc chamber (40), and the switch, distinguishing The fact is that the arc chamber (40) is located between the fixed contact (20) and the conductive element (50) having a first end (51), electrically connected to the second terminal (30), and a second end (52) ending with the bottom side ( 53), and the arc chamber (40) contains many molded conductive plates (41) inserted between the fixed contact (20) and the second end (52) of the conductive element (50), the main part (60) containing the second insulating body (61) which accommodates an element made of ferromagnetic material, mounted next to a plurality of molded conductive plates (41), the main part (60) defining a space (65) for the movable contact to pass during its movement between the first closed position and the second open position. 2. The low voltage switch (1) according to claim 1, characterized in that the molded conductive plates (41) are substantially mutually parallel. 3. A low voltage switch (1) according to claim 2, characterized in that the molded conductive plates (41) are essentially a quadrangular plane with a first main side (411) and a second upper side (412) opposite the first side ( 411), with a recess (413) made in the upper side (412), and the lower points (414) of the recesses (413) of each molded conductive plate (41) are located in the same plane orthogonal to the planes in which the molded conductive plates (41). 4. The low voltage switch (1) according to claim 3, characterized in that the lower points (414) of the recesses (413) of each molded conductive plate (41) are connected by a dashed line. 5. A low voltage switch (1) according to claim 3 or 4, characterized in that the molded conductive plates (41) comprise a first plurality of molded conductive plates (41a) whose main sides (411) lie in the same main plane, and the second set of molded conductive plates (41b), the main sides (411) of which are scaled relative to the main plane in the direction of the lower side (53) from the second end (52) of the conductive element (50). 6. The low voltage switch (1) according to claim 5, characterized in that the upper sides (412) of the molded conductive plates of the first plurality of plates (41a) lie in the same upper plane parallel to the main plane, the upper sides (412) of the molded conductive the plates of the second plurality of plates (41b) are arranged scaled (comb) relative to the upper plane in the direction of the lower side (53) of the second end (52) of the conductive element (50). 7. The low-voltage switch (1) according to claim 1, characterized in that the base for containing the arc chamber (40) is defined in the first housing (10), the base having a lower wall with a first surface adjacent to the fixed contact and a second surface ( 12) adjacent to the first surface and inclined relative to it in the direction of the lower side (53) of the second end (52) of the conductive element (50). 8. The low-voltage switch (1) according to claim 1, characterized in that at least one channel (15) is defined in the first housing (10), which is located in the inner part of the housing with a connection to the outer side, the inlet section ( 16) of the channel (15) is located next to the second end (52) of the conductive element (50). 9. The low-voltage switch (1) according to claim 1, characterized in that the main part (60) is essentially U-shaped with mutually parallel first (63) and second (62) arms connected by a third arm perpendicular to them ( 64), and the space (65) for passing the movable contact is defined between the first (63) and second (62) arms and is open in the direction of the stationary contact (20), the third arm (64) facing the conductive element (50). 10. A low voltage switch (1) according to claim 3, characterized in that the main part (60) is a support surface (66) for supporting at least several molded conductive plates (41) on the upper side (412), wherein the supporting surface (66) is a protrusion (67) suitable for insertion into the space defined by the recesses (413) made in the upper sides (412) of the molded conductive plates (41). 11. The low-voltage switch (1) according to claim 1, characterized in that the movable contact in the first closed position is located in a position that is closest relative to the plurality of molded conductive plates (41) and relative to the stationary contact (20), and in the second open position it is located at a position remote relative to the plurality of molded conductive plates (41) and relative to the stationary contact (20).

Images