The present invention relates to a switchboard multifunction 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 and to provide on the front side access to the retaining means—normally of the screw or spring type—for electrical wires to be connected in order to ensure continuity of the electric circuit section; said continuity being achieved by inserting inside a special seat, accessible from the top side, movable contact elements such as protection fuses, electric circuit breakers or jumpers for connecting together two adjacent terminal blocks.
It is also known that these jumpers may be:
configured with two spring lugs forming the element for engagement inside the seat of the terminal block assembly, with associated electrical contact in the transverse direction determined by the resilient force which pushes the contact legs against the walls of a hole in a longitudinal conductor lamina connecting together the means for retaining the electric wires; and
of the screw type, with a conductor body in the form of an “overturned U”, providing electrical contact in the vertical direction by means of contact of the feet of the overturned U body of the jumper with the longitudinal conductor lamina connecting the opposite means for retaining the electrical wires, said contact being determined by tightening of a screw inside the female thread of a hole formed in the said conductor lamina. The two types have different dimensional measurements both in the transverse width/thickness direction of the terminal block and in the longitudinal lengthwise direction of the terminal block.
With the current terminals of the conventional type, it is therefore necessary to provide a specific and dedicated terminal for each type of movable contact and specifically for each of the two different types of spring or screw jumper, with an obvious increase in the production and warehouse management costs.
EP 0 760 539 A2 describes a terminal block according to the preamble of Claim 1, with a first space (14) centred on the vertical longitudinal access and bounded in the longitudinal direction (X-X) by respective partitions extending in the vertical direction (Y-Y) by an amount such as to allow the insertion of a jumper of the screw type with L-shaped body or alternatively a pair of jumpers of the type with spring lugs specially designed for said central space.
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 technical problem which is posed therefore is that of providing a terminal block, in particular of the type for switchboards designed for wired circuits, which allows the insertion equally well of both screw jumpers and spring jumpers, also simultaneously, without having to replace the terminal block when there is a variation in the type of contact to be inserted.
In connection with this problem, it is also required that this terminal block should have standard dimensions, so that the various types of terminal blocks can be classified in the same size categories and can be produced and assembled in an easy and low-cost manner, and that it should be designed to avoid errors during insertion of the different electrical contact jumpers with the consequent possibility of damaging the connected circuits.
These results are achieved according to the present invention by a terminal block for connecting electrical wires and designed to house, also simultaneously, jumpers of the spring and/or screw type, 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 in
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 or in the transverse direction with other adjacent terminal blocks, respectively, by means of:
a conductor lamina 20 extending in the longitudinal direction X-X for re-establishing the electrical continuity between the electrical wires 2 inserted in the opposite flanks of the terminal block;
a jumper 30 of the screw type and/or at least one jumper 40 of the spring lug type.
In greater detail, said insulating body 10 has a frame 11 substantially in the form of a closed ring and formed so as to define at least one top side 11a and at least two respective flanks 11b arranged opposite to each other in the longitudinal direction X-X.
The body 10 has, formed inside it, at least:
a first pair of seats 12 which are outermost in the longitudinal direction X-X, towards the flanks 11, open in the transverse direction Y-Y and symmetrical relative to the vertical central axis Z-Z and designed to house gripping (retaining/releasing) devices 50 for connection wires 2.
The top wall 11a of the frame 11 may also be provided with (see
first openings 12a extending in the vertical direction Z-Z and in the longitudinal direction X-X, substantially superimposed on the respective seat 12 and designed to connect them with the exterior;
holes 13a with a vertical axis Z-Z for insertion of a label/tag for identifying the circuit connections.
According to the invention, it is envisaged that the terminal block also comprises:
a first space 14 centred on the vertical central axis Z-Z and bounded in the longitudinal direction X-X by respective first partitions 14a interrupted in the vertical direction Z-Z along a section having a height such as to allow insertion of the conductor lamina 20 suitable for restoring the electrical continuity between the opposite wires 2; the partitions 14a are spaced from each other in the longitudinal direction X-X by an amount such as to define a size of the space suitable for housing a jumper 30 of the type with screw 32 and conductor body in the form of an overturned U with vertical legs 31 and insulating body 33 for containing the head of the screw.
a pair of second spaces 15 respectively arranged symmetrically on opposite sides of the first space 14; each second space 15 is bounded in the longitudinal direction X-X by respective second partitions 15a interrupted in the vertical direction Z-Z along a section with a height such as to allow insertion of the conductor lamina 20; the partitions 15a are spaced in the longitudinal direction X-X from the first partitions 14a by an amount such as to define a size of the space 15 suitable for housing a respective jumper 40 of the type with spring lugs 41, The screw-type jumper 30 and spring-lug jumper 40 are not described in detail since they are of the conventional type.
Along the top face 11a, the terminal block has an undercut 16 with a base 16a provided with a first central opening 16b and 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 the pair of spaces 15, respectively, for insertion, in the vertical direction Z-Z, of the respective screw jumper 30 with conductor body and/or spring-lug jumper 40, via the top side 11a accessible for the operator also once the terminal block has been mounted on the electric switchboard.
Each side wall 11b of the frame 11 is provided with a respective opening 17 for introducing the wire 2 in the longitudinal direction X-X.
The said conductor lamina 20, which in use connects the opposite wires 2 together, extends in the longitudinal direction X-X.
Preferably the opposite free ends of the lamina 110 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 of the means for retaining the wire 2.
The conductor lamina 20 has a first central hole 21, with female thread 21a suitable for mating with the thread of the screw 32 of the jumper 30, and a pair of openings 23 with a polygonal, preferably quadrangular form as shown, arranged preferably in a symmetrical manner on opposite sides of the central hole 21 for connection with the contact lugs 41 of the spring jumper 40.
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 better screwing-in of the screw 31 of the jumper 30, further favouring a better conductive contact.
In the example shown in
Although not shown, it is envisaged that the means for retaining the wire 2 may be of the spring type.
As shown:
the laterally open terminal block 10 is assembled by inserting inside it in the vertical direction Y-Y:
the conductor lamina 20, so that its opposite raised ends enter inside the respective seat of the terminal block;
the means 50 for retaining the wire 2;
any signalling devices electrically connected to the electric terminals;
closing the terminal block with a cover 60;
inserting the wires 2 inside the respective insertion seats 17 and operating the actuating screw of the retaining means so as to grip the said wires against the conductor lamina;
inserting at least either one of the screw jumper 30 or spring-lug jumper 40 inside the respective seat 14 or 15;
in the case of a screw jumper, the said screw is operated so as to engage by means of its thread with the female thread 21a of the hole 21 in the lamina 20 which presses the conducting legs of the jumper against the said lamina;
in the event of a jumper 40 with spring lugs 41, this is pushed down fully in the vertical direction of insertion so that the spring lugs enter inside the respective opening 23 and produce the electrical conductive contact by means of the resilient thrust of the contact legs against the internal surface of the openings 23 of the lamina 20.
As shown in
In such an embodiment, each vertical partition 14a bounding the seat 14 has a tooth 14c—which is preferably rigid—extending towards the inside of the seat 14; the two teeth 14c are designed to cooperate with corresponding and complementary teeth 214c—resiliently deformable in the longitudinal direction X-X—of an add-on terminal block 220 which can be mounted on the terminal block according to the invention in the vertical direction Z-Z via the top part thereof.
As shown in
a pair of teeth 19 in the form of an “overturned L” formed on the outermost part of the opposite vertical edges 16c of the undercut 16 formed in the frame 11 of the terminal block; the teeth 19 form a respective L-shaped inset seat 19a formed in the respective vertical edge 16c of the undercut 16.
The teeth 19 with respective seat 19a are designed to receive corresponding projections 119 projecting outwards in the longitudinal direction X-X and formed in the bottom part of the frame 111 of an add-on terminal block 100.
The two frames 11,211 or 11,111 of the two terminal blocks, i.e., base terminal block and add-on terminal block, are joined together so as to form a two-tier—i.e. upper tier and lower tier—assembly according to the non-limiting directional layout shown in the figure.
Both upper-tier terminal blocks 200,100 have a structure similar to that of the lower terminal block, but have a single, small-size, central seat 214,114 for housing a jumper 40 with spring lugs 41; correspondingly the longitudinal conductor lamina 120 has a single polygonal opening 123 for allowing the insertion of the spring lugs and the consequent electrical conduction contact as already described.
The other parts of the upper terminal block 200,100 are similar to those of the lower terminal block and therefore will not be described in detail, but have lengthwise dimensions in the longitudinal direction X-X and vertical direction Z-Z slightly greater than the undercut 16 in the base terminal block.
The longitudinal dimension of the upper-tier terminal block 200,100 is such as to leave exposed the hole 12a for access to the screw for actuating the means 50 for gripping the bottom wire 2 against the conducting lamina 20.
As shown in the examples illustrated in
a connection (
a connection (
a connection (
The assembly of the two-tier terminal block is again similar to that of the base terminal block, although it is envisaged that in this case the closing cover 160 (
It is therefore clear how the terminal block according to the invention is able to house equally well a jumper of the screw type and/or at the same time, at least one, but also two jumpers of the spring-lug type, having dimensions which lie within the standard minimum dimensions.
Furthermore, in addition to the configuration of the insulating body, the particular configuration of the central hole and the lateral openings in the conductor lamina prevent incorrect assembly operations since the spring-lug jumper would not make contact if inserted inside the threaded hole and the screw jumper screw would not have any grip inside the lateral holes.
Number | Date | Country | Kind |
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MI2015A000150 | Feb 2015 | IT | national |