EA000329B1 - Device for connecting an external conductor such as a cable to a contact of an electrical apparatus - Google Patents

Abstract

1. A device for connecting an external conductor such as a cable to a flat contact of an electrical apparatus such as a circuit breaker in a moulded housing comprising a metal block releasable fitted in a terminal compartment at the back of the housing and provided with an elongated through hole for receiving a circuit breaker terminal strip and a clamping screw extending through the upper portion of the block for clamping the cable against the contact, characterized in that the clamping screw (23) comprises at its extreme end situated inside of the metal block (14) a clamping shoe (24), wherein said shoe comprises projections (25-28) or recesses engaging matching recesses (29-32) (or projections) on said terminal strip (6-9) so that the cable is positively retained between the shoe (24) and the contact (6-9) when the screw (23) is tightened. 2. Device according to Claim 1, characterized in that said clamping shoe (24) has a rectangular shape and comprises in each of its angles said projection (25-28) opposite said recess (29-32) of the corresponding shape on said terminal strip (6-9). 3. Device according to Claim 1 or 2, characterized in that comprises a pair of elongated grooves (18, 19), formed correspondingly on two internal surfaces (2a, 2b) of said terminal compartment (2-5) and provided for to receive in it a nut with a holder (20) or similar element. 4. Device according to Claim 3, characterized in that said elongated grooves (18, 19) are located in the lower portion of said terminal compartment (2-5). 5. Device according to Claim 3 or 4, characterized in that three opposite each other orifices (20b, 43, 44) are provided for, correspondingly, in said nut with said holder (20), in flat terminal strip (6-9) and in said lower portion of said terminal compartment (2-5), wherein orifices are provided to pass a fixation screw (50) of a tip (42) or a current-bearing busbar on the flat contact of said terminal strip (6-9). 6. Device according to any of the preceding Claim, characterized in that a plate (41), closing said terminal compartments, is fixed on the rear side of the circuit breaker, wherein said plate (41) comprises an orifice (20) against each clamping terminal or a cleat to pass an electrical conductor, wherein said clamping screw (23) is connected with he protection screen (33), enabling to partial closure of a corresponding orifice (40) of said plate (41) when the screw (23) is tightened. 7. Device according to Claim 6, characterized in that said protection screen (33) constitutes a piece of L-shaped form, one of shelves of which (33a) is mounted freely rotating around the lower portion of said clamping screw (23) between said clamping shoe (24) and the upper portion (34) of said metal block (14), while the other shelf of which (33b) passes in the direction of this upper portion of said metal block (14). 8. Device according to any of the preceding Claim, characterized in that said clamping shoe (24) is fixed on one of the ends of said clamping screw (23) by expansion 9. Device according to any of the preceding Claim, characterized in that an additional flat contact (46) is connected to each of terminal compartment (2, 3, 4, 5) for electrical connection with outer device, e.g. control bulb. 10. Device according to any of the preceding Claim, characterized in that said plate (41), closing said terminal compartments, is fixed on the rear side of the circuit breaker by special projections (41a), provided for on the internal surface of the plate (41) and interacting with recesses of the corresponding shape (41b), made in the rear portion of said housing of the electrical apparatus. 11. Device according to Claim 10, characterized in that said recesses (41b) of said plate (41) and fixed (29-32) on said housing have transverse section of T-shaped form and perpendicular to the longitudinal direction of the electrical apparatus and arranged in areas, separating adjacent terminal compartments. 12. Apparatus for disconnecting electrical circuits such as a circuit breaker, comprising on, at least, one of its big side faces terminal compartments (2-5), inside which flat contacts (6-9) are arranged, characterized in that comprises, at least, one device for connection of an outer electrical conductor according to any preceding Claim. 13. Apparatus for disconnecting electrical circuits such as a circuit breaker according to Claim 12, characterized in that comprising a plurality of devices for connection of an outer electrical conductor according to any of 1-11 Claims, wherein at least one of clamping screw with a contact plate (23) is replaced for one with convex end (22), interacting with the flat contact (6), having recesses

Description

The present invention relates to a device for connecting an external electrical conductor, such as a cable or connecting bus, to a flat terminal of a contact clamp of an electric apparatus such as a molded case circuit breaker.

This device contains a special metal block, which is removably mounted in the terminal compartment provided in the rear of the circuit breaker housing, and in this metal block there is an elongated hole for passing the terminal block of this switch, and a clamp screw passing through the upper part of the metal block for in order to allow the cable to be pressed against the contact plate.

Currently known is the design of the terminal block of the switch of the above type, described, for example, in French patent FR 2.622.350 and used to electrically connect the contact plates of the switch with the cables of the electrical distribution network. However, in the aforementioned document, the cable clamping screws have a convex end, poorly adapted to clamp flexible copper wires or to clamp multicore cables. In addition, such a contact terminal does not provide the possibility of connection to it of crimped contact tips, flat busbars or other specific elements of the electrical distribution circuits.

A connection terminal is also known, which is described, in particular, in French patent FR 2.438.334, in which a compression screw is connected to a compression contact plate of a V-shape designed to ensure correct alignment of the connected electrical wire in its securing position. Such a terminal also does not provide satisfactory crimping of the stranded wire, as well as the connection of an electric wire with a crimped tip.

This invention allows to solve the above problems and provides a device that allows electrical connection to the contact plates of an electrical apparatus, for example, a switch, various types of electrical conductors such as single or multi-core cables, busbars or cable lugs of various types.

The problem is solved in that a device for connecting an external electrical conductor such as a power electric cable to the terminal block of an electric apparatus such as a switch made in a molded case is provided, moreover, this device is characterized in that said clamping screw comprises an end located inside the clamping contact block, a pressure contact plate, wherein said pressure contact plate comprises protrusions (or cutouts) interacting with the cutouts (or, respectively Of course, with protrusions) of the corresponding shape provided on the mentioned contact surface for reliable holding of the external electric cable between the movable contact plate and the contact block of this electric device during the tightening of the clamping screw.

In accordance with a preferred embodiment of the invention, the movable pressure contact plate has a rectangular shape and comprises in each of its four corners a protrusion located opposite the corresponding recess provided on the contact surface of the electrical apparatus.

In accordance with another embodiment of the invention, the device comprises a pair of elongated grooves formed, respectively, on the two inner surfaces of the terminal compartment and designed to connect the nut to the holder.

In accordance with another embodiment of the invention, the grooves are made in the lower part of the terminal compartment.

In accordance with yet another embodiment of the invention, three corresponding holes are provided against each other in a nut with a holder, in a flat contact clip and at the bottom of the terminal compartment, the holes being for passing a screw securing a wire or bus terminal to the flat terminal of the contact clip.

In accordance with another embodiment of the invention, a terminal cover for the terminal compartment is fixed to the rear of the circuit breaker, this plate having an opening for passing an electrical conductor against each terminal, and the pressing screw is connected during translational movement with a protective shield that can partially overlap the corresponding hole in the plate while tightening the screw.

In accordance with another embodiment of the invention, the screen is an L-shaped part, one of the shelves of which is mounted for free rotation around the bottom of the screw between the contact plate and the upper part of the metal block, and the other shelf passes in the direction of the upper part of the block.

In a preferred embodiment of the invention, a clamping contact plate is fixed to one end of the screw shaft by flaring.

In accordance with yet another embodiment of the invention, an additional contact clamp is connected to each of the terminal compartments for electrical connection with an external device, for example, with a lamp for monitoring the presence of electrical voltage.

In a preferred embodiment of the invention, the plate covering the terminal compartments is fixed to the rear of the circuit breaker by means of guiding protrusions provided on the inner surface of this plate and interacting with grooves of a corresponding shape made in the rear of the housing of the electrical apparatus.

These plate mounting grooves on the switch housing have a T-shaped cross section and extend perpendicularly to the longitudinal direction of this switch in the spaces separating two adjacent terminal compartments from each other.

The object of the invention is also an apparatus for disconnecting an electric circuit of a circuit breaker type, comprising at least one of its large lateral sides terminal compartments, inside of which there are flat terminals of contact clamps, this apparatus comprising at least one connection device having the features described above, taken separately or in combination.

According to an embodiment of the apparatus according to the invention, it comprises several such attachment devices and at least one of the clamping screws with the contact plate is replaced by a screw with a convex end cooperating with a flat terminal of the contact clamp having the above-mentioned cutouts.

Other characteristics and advantages of the invention will be better understood from the following description of an example of its practical implementation, which gives links to the figures given in the appendix, including:

FIG. 1 is a perspective schematic view of a rear part of a molded case circuit breaker in accordance with the invention;

FIG. 2 is a schematic perspective view of a clamping terminal of an electrical connection device in accordance with the invention;

FIG. 3 is a schematic perspective view showing the terminal shown in FIG. 2 and equipped with a protective screen in accordance with another embodiment of the invention;

FIG. 4 and 5 are schematic front and cross-sectional views, respectively, of the connection terminal shown in FIG. 2 and 3;

FIG. 6 is a schematic perspective view of a rear portion of a switch, one of the flat terminals of a contact clip of which is electrically connected to a cable lug.

As can be seen in FIG. 1, the circuit breaker D, enclosed in a molded case, has a four-pole configuration and is intended for use in domestic or industrial conditions. The case B of the switch contains on each of its large opposite sides (of which only one large side 1 is shown in this Fig. 1) four terminal compartments 2, 3, 4 and 5. Four terminal compartments of a similar type provided on that side of the switch D, which is not shown in FIG. 1, respectively, contain four contact plates of the distribution electric network of the circuit breaker, while the four terminal compartments 2, 3, 4 and 5 provided on that surface 1 of the circuit breaker as shown in FIG. 1, respectively, contain four load contact plates 6, 7, 8 and 9.

The connection of the contact plates of the electric load 6, 7, 8 and 9 with the external electrical circuits to be protected is most often realized using load terminals, while the connection of the network contact plates to the wires of the distribution electric network is carried out using the corresponding network terminals, and the terminals are mounted in the corresponding terminal compartments directly in places of installation of the electric switch.

In FIG. 1 it can be seen that the load compartment 2, 3, 4 and 5 are equipped with load clamps 10, 11, 12, and 13. Each such load clamp 10, 11, 12 and 13 is a metal block 14 having a generally parallelepiped shape, inside of which an elongated passage 15 is made, where one of the flat terminals of the contact clamp 6, 7, 8 or 9 of the switch D is located. The shape of each terminal compartment 2, 3, 4 and 5 exactly corresponds to the external shape of the metal block 14 so that each block 14 was fixedly mounted in the vertical direction after it was inserted into the corresponding terminal compartment 2, 3, 4 and 5.

In this FIG. 1, it can also be seen that each terminal compartment 2, 3, 4 and 5 contains, on the one hand, at the level of its opposite side surfaces 2a, 26, two additional grooves 16, 17 designed to facilitate removal of the clamp terminal (for example, by special tool), and on the other hand, contains in its lower part two additional grooves 18, 19 designed to insert nuts with a holder 20 into them, which will be described in more detail below in the description.

Each metal block 14 contains in its upper part a threaded hole 21 through which the clamping screw 22, 23 of this terminal is screwed. The terminal clamping screw 22 of the first terminal compartment 2 has a convex end 22a. while the clamping screw 23 of the second terminal compartment 3 in the preferred embodiment is connected by rolling with the clamping contact plate 24.

In accordance with a preferred embodiment of the invention, as shown schematically in FIG. 2, 3, 4, and 5, said quadrilateral-shaped pressure contact plate 24 is provided at its four corners with four projections 25, 26, 27 and 28 oriented in the direction of the flat terminal of contact terminal 6. These four projections 25, 26, 27 and 28 are intended for interacting with four cutouts 29, 30, 31 and 32 made in the corresponding flat terminal of the contact clamp 6, said cutouts 29-32 having a shape corresponding to the shape of the protrusions 25-28, and are located respectively against these protrusions.

Thus, these contact terminals will be adapted for crimping aluminum wires when equipped with a clamping screw 22 with a convex end 22a, and will be adapted to crimping copper wires or stranded wires when equipped with a movable clamping contact plate 24 with protrusions 25-28, as already mentioned above.

In FIG. 4 and 5, it can be seen that the clamp terminal screw 23 provided with the movable clamp contact plate 24 is also equipped with an electrical insulating shield 33. This shield 33 is an L-shaped part made of plastic. One of the shelves of this part 33a is mounted for free rotation on the lower part of the stem of the clamping screw 23, being inserted between the contact plate 24 and the upper part 34 of the terminal, while the other shelf ЗЗ of this part extends towards the upper part of the terminal.

This protective screen 33 is designed to interact with a hole 40 of the corresponding shape (as can be seen in Fig. 1) made in the plate covering the terminal compartments 41 and mounted on the back of the circuit breaker after completing the installation of the corresponding wiring in order to provide electrical protection meeting IP2 standards, as will be discussed in more detail below.

In FIG. 6 it can be seen that a nut with a holder 20 was inserted into one of the terminal compartments 2-5 through the grooves 18, 19, placed under the flat terminal of the clamping contact 9 and designed to enable the cable lug 42 to be fastened to the said terminal 9. For this, two holes 43, 44 are provided respectively in the flat terminal of the clamping contact 9 and in the lower part of the terminal compartment 5 so as to allow the screw 50 of the tip 42 to pass through the contact plate 9, screwed into the hole 20b of the nut 20 with resident 20a.

In FIG. 1 and 6 it can be seen that the circuit breaker case is also provided on its two large opposite side surfaces (only one of which is visible in the figures) with contact pins 46 for supplying electric current with the help of special cable lugs 47 of various devices such as light signaling devices (on the in the appendix figures are not shown), providing control of the presence or absence of electrical voltage.

It should be noted here that the grooves 18, 19 provide the possibility of fixing the cable lugs 42 and can also serve to attach copper busbars or other connecting accessories.

It should also be noted that the terminals, as well as the clamping screws, in the preferred embodiment, are made of aluminum.

And it should also be noted that in the electric switch schematically represented in FIG. 1, all flat terminals of the contact clips contain cutouts.

Below, we will briefly describe the operation of connecting this switch with external electrical circuits to be protected.

At the installation location of the electric switch, the above-described terminals are inserted into terminal compartments 2-5, the flat contact terminals of which 6-9 are intended for connection to the corresponding wires. In the case when these connecting wires are aluminum, the terminal compartments in the preferred embodiment of the invention are equipped with screws 22 with a convex end 22a. The cutouts 29-32 provided in the flat terminals of the contact clips 6-9 provide the best quality electrical contact under these conditions.

In the case when the wires connected to this switch are copper or stranded, the said clamping screws 23 are equipped with clamping contact plates 24 with protrusions 25-28. In this case, the tightening of the clamping screw 23 leads to the introduction of the protrusions of the clamping contact plate 24 into the cutouts 29-32 of the flat terminals of the contact clamps 6, and in this case, the wires are firmly held between the clamping contact plate 24 and the output of the contact clamp 6, which ensures high quality electrical contact.

The operation of tightening the screw 23 also entails a downward movement of the protective shield 33 inserted between the metal block 14 and the plate 41, until this screen 33 overlaps the corresponding hole 40 in the plate 41, which covers the terminal compartments in this way to electrically isolate the clamping terminal from the outside, which meets the above IP2 standards. It should be noted here that the plate 41 must be pre-mounted on the back of the circuit breaker using the protrusions 41a made on this plate 41 and interacting with the grooves 41b made on the housing of this switch, as mentioned above.

In order to connect the crimped cable lug 42, copper busbar or other connecting accessories, it is enough to insert the nut 20 with the holder 20 a into the lower grooves 18, 19 and attach the cable lug 42 to the flat terminal of the contact clamp 9 by means of the clamping screw 50 passing through four holes 51, 43, 20b and 44 provided respectively in the cable lug 42, in the contact plate 6 (in the nut 20) and in the lower part of the terminal compartment 5.

Thus, in accordance with the invention, it is possible to implement a device that allows the flat terminals of contact terminals 6, 7, 8 and 9 to be connected to various types of external electrical conductors, namely, copper wires, aluminum wires, multicore wires, and special cable lugs, connecting busbars, etc., are simple and quick enough.

It goes without saying that the present invention is not limited to the method of its implementation described above, which is given here only as an illustrative example.

On the contrary, this invention encompasses all technical equivalents of the agents described above, as well as their combinations, which do not contradict the spirit of this invention.

Claims (13)

CLAIM 1. A device for connecting an external electrical conductor such as a cable to a flat terminal of a contact terminal of an electrical apparatus of a molded case switch type, comprising a metal block that is removably installed in the terminal compartment provided in the rear part of the switch case, and an elongated through hole is made in the metal block switch terminal block, and a clamping screw that passes through the top of the metal block and is designed to provide a pressure cable to the terminal of the contact clamp, characterized in that the clamping screw (23) contains at its end located inside the metal block (14), the pressure contact plate (24), and the plate (24) contains protrusions (25-28) or notches, which interact with the notches (29-32) or, respectively, with protrusions of appropriate shape provided on the flat terminal of the contact clip (6-9), for secure holding of the electric cable between the pressure contact plate (24) and the flat terminal of the contact clip (6- 9) when tightening the clamp o screws (23). 2. Device by π. 1, characterized in that the clamping contact plate (24) has a quadrangular shape and contains in each of its corners a protrusion (25-28) located against a notch (29-32) of a corresponding shape provided on the flat terminal of the contact clip (6-9 ). 3. Device by π. 1 or 2, characterized in that it contains a pair of elongated grooves (18, 19), formed respectively on two internal surfaces (2a, 2b) of the terminal compartment (2-5) and designed to accommodate a nut with a holder (20) or similar item. 4. The device according to p. 3, characterized in that the elongated grooves (18, 19) are made in the lower part of the terminal compartment (2-5). 5. The device according to p. 3 or 4, characterized in that three holes facing each other (2 () b. 43, 44) are provided, respectively, in the nut with the holder (20), in the flat terminal of the contact clip (6- 9) and in the lower part of the terminal compartment (2-5), and the holes are designed for the passage of the fastening screw (50) of the tip (42) or the busbar to the flat terminal of the contact clip (6-9). 6. Device according to any one of paragraphs. 1-5, characterized in that the terminal plate covering the compartments (41) is fixed on the back of the switch, and the plate (41) contains an opening (40) against each contact clip or terminal for passing an electrical conductor, and the clamping screw (23) is connected at forward movement with a protective screen (33), made with the possibility of partial overlapping of the corresponding hole (40) of the plate (41) while tightening the clamping screw (23). 7. The device according to claim 6, characterized in that the protective screen (33) is formed by a L-shaped part, one of the shelves of which (33a) is mounted freely rotating around the lower part of the clamping screw (23) between the pressure contact plate (24) and the upper part (34) of the block (14), and the other shelf of which (33b) runs in the direction of this upper part of the metal block (14). 8. Device according to one of claims 1 to 7, characterized in that the pressure contact plate (24) is fixed on one of the ends of the pressure screw rod (23) by means of flaring. 9. Device according to one of the claims 1 to 8, characterized in that an additional flat terminal of the contact clip (46) is connected with each of the terminal compartments (2, 3, 4, 5) for electrical connection with an external device such as an alarm light bulb or lack of electrical voltage. 10. Device according to one of claims 1 to 9, characterized in that the plate (41) covering the terminal compartments is fixed on the back of the switch using special projections (41a) provided on the inner surface of the plate (41) and interacting with slots of the corresponding form (4 lb), made in the back of the housing of the electrical apparatus. 11. The device according to claim 10, characterized in that the grooves (41b) of the fastened plate (41) on the body have a T-shaped cross section, run perpendicularly relative to the longitudinal direction of the electrical apparatus and are located in spaces separating adjacent terminal blocks. compartments. 12. An apparatus for disconnecting electrical circuits of the type of switch, containing, on at least one of its large lateral sides, terminal compartments (2-5), inside of which there are flat terminals of contact clips (6-9), characterized in that it contains at least one external electrical conductor attachment device according to any one of the above points. 13. The apparatus for disconnecting electrical circuits of the type of switch according to claim 12, characterized in that it contains several devices for connecting an external electrical conductor according to any one of items 1 to 11, and at least one of the clamping screws with the contact plate (23) is replaced on the clamping screw with a convex end (22), interacting with a flat terminal of the contact clip (6), having cutouts (29-32).