TEXT OF THE DESCRIPTION

SCOPE OF THE INVENTION

The present invention is included in the electrical field and in particular in the plant engineering sector. More in detail, said invention relates to electrical panels and all those situations in which one or more electrical cables must be connected, for example, on a terminal block.

In fact, it is known that every time an electrical cable must be connected for example to a panel of an electric machine or more simply to an electrical panel, use is made of connection systems that provide special housings for said cables and clamping systems that should allow both excellent electrical continuity, especially in the case of high amperages, and excellent sealing over time of said connections.

STATE OF THE ART

To allow the connection and tightening of the cables on the electrical panels, solutions are usually adopted that usually provide for the insertion of the cables in housings present in the electrical panels that are partially or totally coated with conductive material, the cables are then squeezed/com pressed by a terminal against the conducting wall of the housing.

However, this solution practiced for years in the art has a major disadvantage: as is well known to experts in the field, once the cable is inserted and tightened, it must at least be periodically inspected to check if it is still firmly connected to the panel. This need arises from the fact that micro and macro-heatings to which the cable is subjected when the current passes through it tend to cyclically expand all the metal parts of which the connection between said cable and the conductive wall of the housing is composed producing, as well known to experts in the field, frequent loosening in the tightening of the cable inside the housing and therefore a distancing of the cable itself from the conductive wall. This occurrence causes considerable and not insignificant problems: when the contact between the cable and its housing becomes precarious, it creates dangerous and undesirable situations such as possible flames, ignition of local voltaic arcs with further rapid deterioration of the parts used for both tightening and electrical conduction between the cable and the panel and still pressure losses and therefore power supply problems towards the machines connected to the electrical panel, even in extreme cases it is also possible that the conductor cable comes out the housing with danger of short circuits and danger also for people who come into contact with it in case of maintenance.

It is an object of the present invention to describe a safety system for electrical panels that prevents the loosening of the contact between the electrical cable and the conductive parts of the panel itself.

It is still an object of the present invention to describe a system of safety for electrical panels that is economical and easily achievable.

It is a further object of the present invention to describe a safety system for electrical panels that can work with any cable that can be integrated with any type of electrical panel.

It is an object of the present invention to describe a safety system for electrical panels that can be operated with common tools and quickly.

It is still an object of the present invention to describe a safety system for electrical panels that solves all the aforementioned problems of known art.

BRIEF DESCRIPTION OF THE INVENTION

These and further objectives will be achieved as described below by the innovative safety system for electrical panels that will be integrated with electrical panels, replacing the old system for connecting electrical cables to the electrical panel, it is described a: safety system for electrical panels integrated with electrical panels, whereby said system comprising at least one electrical panel comprising at least one housing in which one or more electrical cables are inserted to connect it/them to the panel, said housing comprising conductive surfaces which come into contact with said cable, said system being characterized in that it comprises within said housing at least one cable-holding tab comprising in turn at least a hinge on a first end side thereof to be hinged inside said at least one housing and comprising on a second end side at least one top surface which faces a first surface of said housing, between said top surface and said first surface forming a further secondary housing in which the electrical cable to be blocked is inserted, said cable-holding tab, and in particular its inner face, being apt to squeeze and hold the cable in position on said first surface of said housing, at least one compression spring is further included positioned between an external face of said cable-holding tab and a second internal surface of said housing, opposite to the first, said second internal surface acts as a stop, said spring being apt to push said cable-holding tab against said cable, on said second internal surface being realized at least one threaded hole, said threaded hole being apt to house a threaded element, included in said system, able to screw into said hole passing through the central axis of said spring and the end part of said threaded element coming into contact with said cable-holding tab in a locking position to lock the cable-holding tab against said cable in a stable manner, said spring being compressed to always maintain stable and constant pressure on the cable locked in said housing.

Said tab was pressed including a hooked end on the inner face of said top surface to more firmly hold the electric cable with which it will come into contact.

Or in an embodiment variant said cable-holding tab comprising on the inner side of said top surface an end or toothed surface to engage with the cable and therefore better hold the electrical cable with which it will come into contact.

In a variant, said at least one first side of said housing comprises a knurled conductive surface for engaging and holding more easily said electric cable which is housed in said secondary housing. Said threaded element being a screw of any pitch.

Said screw having a head of any kind.

Brief Description of the figures.

Fig.1 a and 1 b show an electrical panel comprising several safety systems for electrical panels object of the present invention and a section of said safety system for electrical panels in a preferred variant of the invention; in fig.2a, 2b, 2c, 2d the cable-holding tab is shown in a rest position and in various forms of construction and some details of the tab itself.

Detailed description of the figures

In fig. 1a and 1 b, therefore, an electrical panel 100 comprising one or more safety systems 1 object of the present invention is visible. In particular are visible with reference to a single safety system 1 , a housing 2 of said system obtained in the electrical panel 100 where an electrical cable 10 will be inserted to be locked in said housing by means of the safety system object of the present invention.

Said housing 2 comprises in a preferred variant at least one knurled conductive surface 21 made on the first inner surface 11 of the housing, said conductive surface will be in contact with the cable 10 (with or without a cable terminal of known art), that is, the cable will be pressed against it; on the opposite side of said first inner surface 11 a second inner surface 17 of the housing is visible in which a threaded hole 19 is obtained. A threaded element 4 of said system 1 having an end apt to be engaged by a tool such as a screwdriver or an Allen wrench or any shape suitable for the purpose is screwed into said threaded hole 19. On the bottom 26 of said housing is hinged by means of a hinge 5 a cable-holding tab 3 on its terminal side 8, said cableholding tab comprises a top surface 9 comprising a hooked surface 20 or in a variant a toothed surface 24 to hold with greater efficiency the cable in contact with the knurled surface 21. In contact with said cable-holding tab 3 on its external face 16 and in contact with said second inner surface 17 there is a spring 6 held in position between the two parts by means of the engagement of said spring in a seat 30 made on the external face 16 of the cable-holding tab 3 and a second seat 31 made on the second inner surface 17 of the housing.

In a preferred example of the present invention, said threaded element 4 is positioned inside the spring 6. By manually moving (as better described below) said tab was pressed in the opposite direction of the knurled surface 21 and inserted the cable 10 into position in the housing 2, said spring 6, once the tab is released, will exert a force on the cable-holding tab directed towards the cable 10 being said spring now in compression. This force will already be sufficient to lock the cable 10 in position inside the housing, i.e. in firm contact with the knurled conductive surface 21 and the top surface 9 of said tab in particular of its inner face 15 where the hooked 20 or toothed 24 surfaces to achieve an effective electrical contact between the cable itself and said surface, this operation will be facilitated by the presence of the hooked 20 or toothed 24 surfaces. In a completely innovative and advantageous way, for the maintenance of said position, which we will define as "locking", the threaded element 4 is screwed until it meets the cable-holding tab 3 with the effect of creating a further thrust on said tab and creating a rigid mechanical block of the cable-holding tab in contact with the cable, the tab will in fact be prevented from moving. Two forces will therefore act on the cable-holding tab 3: that of the spring 6 and that of the threaded element 4, which will advantageously effectively prevent the loosening of the contact between the knurled conductive surface 21 and the electrical cable 10; in addition, the possibility of making the threaded element with a very short pitch will allow fast and safe tightening (for example, the threaded element may have a pitch to reach the locking position with half a screwdriver turn). Even in the case of heating of the contact area, in fact, a thermal expansion of the metal parts that could loosen the pressure of the cable-holding tab on the electrical cable will be compensated by the force of the spring 6 that will continue to keep the cable-holding tab in contact with the cable and then compress it on the knurled surface 21 (knurled to prevent the sliding of the electric cable on it and keep it more easily in position). Said cable-holding tab 3 is also shaped on its terminal side 9 with a hooked 20 or toothed 24 surface apt for holding the cable in place by working synergistically with the knurled surface 21 .

Fig.2a instead shows a rest configuration of the safety system 1 . Advantageously, in fact, to insert the electrical cable inside the secondary housing 12, no special operations or dedicated tools will be necessary: in said rest position, the spring 6 will be unloaded and sized so as to keep the cable-holding tab a few mm away from the knurled surface 21 , the threaded element 4 will instead be loosened allowing a rotation of the cable-holding tab 3 around the hinge 5. An operator will then provide for example by means of a screwdriver or a similar object inserted into the remaining opening between the cable-holding tab 3 and the knurled conductive surface 21 , to move the cable-holding tab 3 away from the knurled conductive surface 21 , the spring 6 will compress and when the cable 10 is in place, the screwdriver removed, the cable-holding tab will be pushed by the spring to compress the cable with a force appropriately defined by the type and material of the spring itself. At this point, tightening the threaded element 4 will permanently lock the safety system 1 .

Fig. 2b, 2c, 2d shows a preferred representation of the cable-holding tab 3 in which a seat 30 for the spring 6 and a hooked surface 20 are highlighted suitable for retaining the cable 10. Said hooked surface can also be made in other variants, of variable geometry also depending on the size of the cable-holding tab itself.

In particular, Figure 2d shows a possible non-limiting variant of the geometry of said cable-holding tab with a toothed end 24. Said cable-holding tab can also be hinged in the housing 2 for example through a pin as indicated in the proposed figures but also through other systems as long as it is able to carry out the movements necessary for the cable-holding tab to be able to be functional for the purpose (semi-hinges, movable joints, etc., solutions already present in the known art).

From what is described in the attached figures, there are obvious advantages and problems of known art brilliantly solved by the present invention, in fact the present safety system for electrical panels is able to solve all the aforementioned problems of the known art, it goes without saying that variants in non-essential details of the present invention are always protected by the same inventive scope, so changes in the shape and/or material of the cable-holding tab, number and shape of cable housings, type of electrical panels, holding means, etc., are all to be considered as embodiments of the present invention as better defined by the appended claims.