The present invention relates to a switchboard terminal block for connecting electrical wires.
It is known, in the technical sector relating to the production of switchboards for the wiring of electrical installations, to use terminal blocks designed to be mounted on associated supports, such as DIN-standard rails, and to provide on the front side access to the means—normally of the screw or spring type—for retaining electrical wires to be connected in order to restore continuity of the various sections of the electric circuit; said continuity being achieved by inserting inside a special seat, accessible from the front side, movable contact elements such as protection fuses, electric circuit breakers or jumpers for connecting together two or more adjacent terminal blocks.
It is also known that these connection jumpers may be:
The two types of connection jumper have different dimensional measurements both in the transverse direction of the width/thickness of the terminal block and in the longitudinal lengthwise direction of the terminal block.
It is also known that the increasingly greater demand for connections and branched junctions both in the electrotechnical sector and in the electronics sector, where it is required to direct also the control signals, results in the design of electric switchboards which have increasingly larger dimensions and consequently occupy a greater amount of space in the installation premises, resulting in greater costs due to the larger dimensions also of the installation cabinets.
EP 2 204 886 A1 describes a terminal block with a central space divided into two sub-spaces by a central dividing wall for receiving the separate legs of a shunt which may be for example a fuse, a relay or a signalling lamp. The configuration of the central space is such as to allow the insertion and subsequent extraction of the shunt in the vertical direction.
DE 10 2008 009986 describes a terminal block which has a detent lug corresponding to a detent hook of a detent arm formed near to a socket for a connection plug. The lug engages the detent hook of the detent arm in a reversibly locked condition of the connection plug in the socket, which plug may be extracted vertically from the socket by acting on the detent arm.
DE 295 02 186 U describes a terminal block assembly with means for reversible coupling in the direction of insertion of an electric connector.
All the cited documents illustrate electrical connection components to be inserted in a base terminal block, which by their very nature must be able to be subsequently extracted with ease from the base terminal block along the direction of insertion therein.
The technical problem which is posed, therefore, is to provide a terminal block, in particular of the type for wired-circuit switchboards, which allows the connection/branching capacity of the switchboard to be increased without having to increase its dimensions in particular in the longitudinal direction of the width, but preferably also thickness.
In connection with this problem, it is also required that this terminal block should have small dimensions and be able to be produced and assembled in an easy and low-cost manner and that it should be designed to avoid errors during the insertion of the different electrical contact jumpers with the consequent possibility of damage to the connected circuits.
These results are obtained according to the present invention by a base terminal block for connecting electrical wires, in particular for electric switchboards, designed for coupling in the vertical direction with an auxiliary terminal block so as form a multiple, modular, two-tier terminal block according to the features of the claims.
The present invention relates furthermore to an auxiliary or “add-on” terminal block which can be engaged with the base terminal block, for the connection of electrical wires in particular for electric switchboards, according to the features of the claims, and a two-tier base and add-on terminal block assembly according to the features of the claims.
Further details may be obtained from the following description of non-limiting examples of embodiment of the subject of the present invention, provided with reference to the accompanying drawings, in which:
As shown, for the sake of easier description and without a limiting meaning, a set of three reference axes are assumed, i.e. in the longitudinal direction X-X, corresponding to the lengthwise dimension of the terminal block; transverse direction Y-Y, corresponding to the width or thickness of the terminal block; and vertical direction Z-Z, corresponding to the heightwise dimension of the terminal block and the direction of superimposition of an add-on terminal block on top of a base terminal block, and for easier illustration coinciding with the central vertical axis of the terminal block.
For the sake of easier description, and using the directional layout shown in the figures by way of example, the following are also assumed: a bottom part corresponding to the part of the base terminal block for coupling with a DIN-standard rail B (
According to the invention, it is envisaged that the terminal block comprises (
As will emerge more clearly below, the terminal block may be completed so as to form the various electrical connections in the longitudinal direction X-X between the opposite wires 2 by means of:
In its minimum configuration shown in
The front wall 11a of the frame 11 also has, formed therein, first openings 12a extending in the vertical direction Z-Z and in the longitudinal direction X-X, substantially arranged above the respective seat 12 and designed to connect the latter with the exterior, for the introduction of means for operating the retaining means 50;
The screw jumper 30 and/or spring-lug jumper 40 is/are designed to establish an electrical contact between the terminal block and one or more additional terminal blocks adjacent to it in the transverse direction Y-Y, and are not described in detail since they are of the conventional type.
Along the top side 11a, the terminal block has an undercut 16a with base 16a having a first central opening 16b for inserting in the vertical direction Z-Z, from the front side 11a accessible for the operator also once the terminal block has been mounted on the electric switchboard, the conductor body of a screw-type jumper 30.
In the case of a terminal block with spaces 15 for housing a spring-lug jumper 40, the bottom of the undercut 16 has two second lateral openings 16c arranged on opposite sides of the central opening 16b. The three openings 16b and 16c form the openings towards the top side 11a of the first space 14 and, where present, of the pair of spaces 15, respectively.
According to the invention, it is envisaged that in all its embodiments the base terminal block has means for coupling with corresponding means of an auxiliary or “add-on” terminal block described below, without the possibility of movement or extraction in the vertical direction along which the two terminal blocks are arranged on top of each other.
In a first embodiment of the base terminal block according to the invention (
In a second preferred embodiment of the base terminal block according to the invention (
The said conductor lamina 20, which during use connects the two opposite wires 2 together, extends in the longitudinal direction X-X.
Preferably, the opposite free ends of the lamina form a tip 22 inclined upwards and designed to engage with a corresponding internal seat 18 provided on each flank 11b of the frame 11 so as to stably fasten the conductor lamina 20 to the insulating body 10.
Preferably, each tip 22 has an incision 22a designed to engage with a corresponding relief 18a in the seat 18 in order to axially retain the lamina when it undergoes an axial deformation owing to the thrust exerted by the screw 52 of the means 50 for retaining the wire 2.
The conductor lamina 20 has a first central hole 21, with female thread 21a designed to mate with the thread of the screw 32 of the jumper 30.
Preferably, for the embodiment shown in
During use (
Preferably, the central hole 21 is obtained by means of deep-drawing so as to form an extended collar 21b in the vertical direction Z-Z designed to allow further screwing of the screw 31 of the jumper 30 and favour a better conductive contact.
In the examples shown, the means 50 for retaining the electric wire 2 are of the clamp type 51 with actuating screw 52; the head 52a of said screw 52 is accessible from the outside via said vertical-axis hole 13a through which it is possible to insert the operating tool for rotating the screw, the tip of which, reacting against the surface of the lamina 21, recalls the clamp 51 which grips the end 2a of the wire 2 between clamp and lamina.
Although not shown, it is envisaged that the means for retaining the wire 2 may be of the spring type which can be operated with or without a suitable operating button.
As shown:
The present invention also relates to an auxiliary or “add-on” terminal block suitable for coupling with the base terminal block already described.
In a first embodiment (
The other parts of the top terminal block 100 are similar to those of the bottom terminal block and are therefore indicated by identical reference numbers preceded by 1, but are not described in detail.
In the first embodiment of the add-on terminal block, it is envisaged that it has, in its bottom part, a pair of substantially L-shaped projections 119 projecting outwards in the longitudinal direction X-X and forming a respective inner seat 119a in the form of an “overturned L”.
The projections 119 and the seats 119a of the add-on terminal block are complementary and correspond to the projections 19 and seats 19a of the base terminal block, in order to allow the respective and corresponding insertion in the transverse direction Y-Y and, therefore, relative coupling designed to form an assembled unit with two tiers (the directional layout shown in the figures is not limiting), i.e., an upper tier (add-on terminal block) and bottom tier (base terminal block) which are fixed and cannot be disengaged from each in the vertical direction Z-Z along which they are arranged one on top of the other.
In greater detail, the two-tier assembly is realized by joining together the coupling means of the top part of the base terminal block with the complementary coupling means of the bottom part of the add-on terminal block.
Preferably the add-on terminal block also has flanges 117 extending in the vertical direction Z-Z from the transverse peripheral edges of its bottom part and located in a central position with respect to the two projections 119; the flanges are designed to form elements for ensuring guiding and mechanical stabilization as well as electrical insulation once engaged.
According to a further embodiment of the add-on terminal block (
In this embodiment, the coupling means comprise:
Preferably the add-on terminal block comprises two guide elements 225 symmetrically arranged on opposite sides of the protrusion 224 and designed to be inserted inside the seats 15 of the base terminal block so as to ensure a more stable coupling.
For both embodiments, the add-on terminal block has a dimension in the longitudinal direction X-X slightly bigger than the dimension in the longitudinal direction of the undercut 16 in the terminal block so as to leave exposed at least the access hole 12a for the actuating screw of the means for clamping the bottom wire 2 against the conductor lamina 20.
Once closed in the transverse direction with a cover, the two terminal blocks are mechanically coupled together in a fixed and irreversible manner, eliminating the risk of accidental extraction of the add-on terminal block in the vertical direction, with the consequent interruption of the electrical connections.
As shown in
As shown in the examples of
In detail the examples show:
It is, therefore, clear how, with the base terminal block and the add-on terminal block according to the invention, it is possible to form two-tier terminal blocks which are able to increase the number of connections/branched junctions of a terminal block assembly for electric switchboards, without a substantial increase in the longitudinal and transverse dimensions and therefore of the overall volume of the terminal block assembly and associated housing container.
Number | Date | Country | Kind |
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MI2015A000151 | Feb 2015 | IT | national |