Terminal and fuse box with double electrical insulation for lighting pole junctions

Abstract: A terminal and fuse box with double electrical insulation for lighting pole junctions, comprising a box-like element (2) which can be interlocked frontally in a vertically elongated opening of a pole and whose inlet can be closed by a cover (11) which is hinged on a horizontal axis, the bottom face of the box-like element (2) having coupling means for an interchangeable terminal strip (26) contained in an enclosure made of insulating material, engagement means (17) being provided on the inner face of the cover for at least one fuse holder (18).

Description: The present invention relates to a terminal and fuse box with double electrical insulation for lighting pole junctions. Terminal and fuse boxes for street lighting poles are known which are used to provide the electrical connections between the power supply cables and the cables for connection to the light sources and are internally provided with the protection fuses. So-called double-insulated terminal boxes are also known which comprise a box and a corresponding cover, both made of insulating material and designed to be rigidly coupled to the metallic pole, and a terminal board, made of insulating material, which is fixed to the box and thus provides double insulation of the terminals affected by the flow of electric current. These boxes are fitted at vertically elongated openings of the poles whose inlet, after providing the electrical connections and fitting the box, is closed by a cover which can be fixed to the pole by means of screws: double protection of the electrical junctions is thus obtained, as required by applicable standards. The terminal boxes currently manufactured suffer drawbacks related to the speed of fuse replacement and to the fact that during fuse replacement operations the live cables, which can be accessed easily, may be touched unintentionally. Additionally, in conventional boxes the side where the electrical cables enter is not closed effectively in every operating condition: in practice, access for a certain number of cables having a large cross-section must be ensured, while in some cases there is a smaller number of cables and/or the cables have a reduced cross-section. A terminal and fuse box with the features set form in the preamble of claim 1 is known from FR-A-2 644 010. The aim of the present invention is to obviate the noted drawbacks of conventional devices, i.e., to provide a terminal and fuse box with double electrical insulation for lighting pole junctions which allows to replace the fuses in very safe conditions and in which the cable entry side is effectively closed in any operating condition. Within the scope of this aim, an object of the present invention is to provide a structure which is simple, relatively easy to provide in practice, safe in use, effective in operation, and has a relatively low cost. This aim and other objects which will become better apparent hereinafter are achieved by a terminal and fuse box with double electrical insulation for lighting pole junctions according to the present invention, comprising a box-like element which can be interlocked frontally in a vertically elongated opening of a pole whose inlet can be closed by a cover which is hinged on a horizontal axis, characterized in that the bottom face of the box-like element has quick coupling means for an interchangeable terminal strip contained in an enclosure made of insulating material, and in that on the inner face of the cover there are provided quick coupling means for at least one fuse holder. Further characteristics and advantages of the present invention will become apparent from the following detailed description of a preferred but not exclusive embodiment of a terminal and fuse box with double electrical insulation for lighting pole junctions according to the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein: Figure 1 is a side view of a terminal and fuse box with double electrical insulation for lighting pole junctions according to the invention; Figure 2 is a side view of the cover of the box; Figure 3 is a sectional side view of the box with a terminal strip for three metallic contacts in a four-pole version; Figure 4 is a side view of the cover, orientated with respect to Figure 3 in the open configuration; Figure 5 is a side view of a fuse holder; Figure 6 is a front view of the box with an installed four-pole terminal strip; Figure 7 is a sectional side view, taken along a median plane of the box; Figure 8 is a schematic side view of the dimensions of a terminal strip for three metallic contacts in a four-pole version; Figure 9 is a sectional side view of the box with a terminal strip for three metallic contacts in the two-pole version; Figure 10 is a front view of the box with an assembled two-pole terminal strip; Figure 11 is a schematic side view of the dimensions of a terminal strip for two metallic contacts; Figure 12 is a front view of the cover of the box; Figures 13a, 13b, 13c are orthographic projection views of a fuse holder; Figures 14a and 14b are orthographic projection views of an insulating base for a fuse holder; Figure 15 is a front view of a plate for closing the lower face of the box; Figure 16 is a front view of a box with the associated cover; Figure 17 is a front view of the outline of the opening to be provided on the pole in order to insert the box according to the invention. With particular reference to the above figures, the reference numeral 1 generally designates a terminal and fuse box with double electrical insulation for lighting pole junctions according to the invention. The box 1 comprises a box-like element 2 which can be snugly fitted frontally in a vertically elongated rectangular opening 3 with semicircular upper and lower sides, formed in the pole P (see Figure 17). The lower face 4 of the element 2 is open for the passage of the cables and has, along its sides, means for sliding coupling, slots 5a and 5b, for a closure plate 6 whose bottom end is rounded so as to form a concave portion and is provided with an edge 6a and with at least one pin, two protruding pins 7a and 7b in the particular case, which can be engaged by means of fastening straps 8 with the power supply cables and with an extension 9 of the bottom of the box-like element. The plate 6 is affected by a plurality of deep notches 10 which allow to manually break the plate to the required size so that the lower face crossed by the single- and multiple-pole cables is appropriately closed, while the extension 9 is narrow and is provided with notches 9a for the straps 8. The inlet of the box-like element 2 can be closed by a cover 11 which is hinged about a lower horizontal axis: for articulation to the box-like element 2, the cover has, in a downward region and to the sides, two substantially T-shaped pins 12b which are adapted to cooperate with corresponding contoured seats for rotation, designated by the reference numeral 13a, and for sliding, designated by the reference numeral 14a, which are provided on the internal surfaces of the sides of the box-like element in order to allow to disengage the cover 11 from the box-like element 2 when the cover is open: the reference numeral 13b designates the extension of the rotation seats formed in the sides of the box-like element 2 for molding reasons. The cover 11 has a vertically elongated front portion 11a connected, in an upward region, to an inclined portion 11b ending with a short portion 11c which is parallel to 11a and is crossed by a screw 13 for fastening against a perforated block 14 rigidly coupled to the outside of the upper wall of the box-like element 2: in a downward region, the cover has a tapering L-shaped portion 11d. On the sides of the inlet of the box-like element 2 there are provided elongated ridges 15 for snap engagement with corresponding ridges 16 of the sides of the cover. Engagement means 17 for a fuse holder 18 are formed on the inner face of the cover 11 and comprise a protruding pin with an enlarged head 19 which is arranged at the center of the internal face of the cover and passes through a central hole 20 of an insulating fuse holder base 21 and then through a hole 22 of the fuse holder, with which it can be engaged by snap action: the insulating base 21 conveniently has, in turn, a pin 24 designed to engage by snap action with an additional hole 25 of the fuse holder. The reference numeral 26 designates a terminal strip which is interchangeable and can be provided with two or more contacts: the terminal strip is constituted by a plurality of metallic cores 27 with two or more holes 28a, 28b, 28c and screws 29a, 29b, 29c for the metallic connections to the cables: the metallic cores 27 are stepped so as to allow to arrange the matching cables one above the other; the cores 27 are fitted in corresponding compartments formed in a contoured enclosure 30 which is closed in a downward region by a cover 31, and both said enclosure and said cover are made of insulating material. The bottom face of the box-like element 2 has coupling means for the terminal strip comprising two lateral ridges 32a, 32b of the internal faces of the sides of the box-like element 2, which guide two corresponding elongated external slots 33a, 33b of the terminal strip, and a tooth 34 of the bottom of the box-like element which engages by snap action a corresponding elastic tab 35 of the base of the terminal strip. A cutting template is molded on an outer face of the box-like element 2 and shows the lengths 36a, 36b of the cables and of the portions of the sheaths of the wires to be stripped which allow the operator to perform stripping operations without making mistakes. It is thus evident that the invention achieves the intended aim and object, and in particular that a terminal and fuse box with double electrical insulation for lighting pole junctions has been provided which allows to replace the fuses and the corresponding printed circuit (by way of the fact that they are associated with the cover) in extreme safety without approaching the cables, and in which the cable inlet side is effectively closed in any operating condition, by means of the plate 6: moreover, the quick couplings of the terminal strip to the element 2 and of the fuse holder with the corresponding insulating fuse holder base to the cover allow to rapidly adapt the box to the various operating requirements. The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the invention as defined in the appended claims. All the details may furthermore be replaced with other technically equivalent ones. In practice, the materials used, as well as the shapes and the dimensions, may be any according to requirements without thereby abandoning the scope of the protection of the appended claims. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims: A terminal and fuse box with double electrical insulation for lighting pole junctions, comprising a box-like element (2) which can be interlocked frontally in a vertically elongated opening (3) of a pole (P) whose inlet can be closed by a cover (11) which is hinged on a horizontal axis, characterized in that the bottom face (4) of the box-like element (2) has quick coupling means (32a, 32b) for an interchangeable terminal strip (26) contained in an enclosure (30) made of insulating material, and in that on the inner face of the cover (11) there are provided quick coupling means (17) for at least one fuse holder (18). The box according to claim 1, characterized in that the lower face (4) of the box-like element (2) is open for the passage of single- and/or multiple-pole cables and comprises, along its sides, sliding coupling means (5a, 5b) for a closure plate (6) whose end is rounded and provided with at least one cantilevered pin (7a, 7b) which can be engaged, by means of a fastening strap (8), with the power supply cables and with an extension (9) of the bottom of the box-like element (2). The box according to claim 2, characterized in that said quick coupling means (32a, 32b) for said terminal strip (26) comprise two lateral ridges (32a, 32b) of the sides of the box-like element (2) adapted to guide two corresponding elongated slots (33a, 33b) of the terminal strip (26) and a tooth (34) of the bottom of the box-like element (2) which is adapted to engage by snap action a corresponding elastic tab (35) of the base of the terminal strip (26). The box according to claim 1, characterized in that said quick coupling means (17) for at least one fuse holder (18) comprise a pin (19) which protrudes from the internal face of said cover (11) and is adapted to pass through a central hole (20) of an insulating fuse holder base (21) and then through a hole (22) of the fuse holder (18) to which it can be coupled by snap action. The box according to claim 1, characterized in that a cutting template is molded on an outer face of the box-like element (2) and shows the lengths (36a, 36b) of the portions of sheath of the wires to be stripped. The box according to claim 1, characterized in that elongated ridges (15) are provided on the sides of the inlet of said box-like element (2) for the snap engagement with corresponding ridges (16) of the sides of said cover (11). The box according to claim 1, characterized in that for articulation to the box-like element (2), said cover (11) has, in a downward region and to the sides, two substantially T-shaped pins (12a, 12b) which are adapted to cooperate with corresponding contoured seats (13a, 14a) for the rotation and sliding of the inner surfaces of the sides of the box-like element (2) in order to allow disengagement of the cover (2) from the box-like element (2) when the cover (11) is open.

Inventors: HAZAN HASMONAI, HAZAN, HASMONAI
Applicants: CONCHIGLIA SPA, CONCHIGLIA S.P.A.
Application year: 2000
Main classification: H01H85
IPC codes: H01R13, H01H85