Fuse unit and manufacturing method therefor

Abstract: An electrically conductive metal plate (2) is stamped out, so as to yield a fuse unit (1) including an input terminal (3) and several output terminals (4). The fuse unit further comprises a predetermined locus where fuse element portions (5) are to be formed later. A surface area of fuse unit (1) including this predetermined locus is then molded with an insulator material (7). Thereafter, the fuse element portions (5) are formed in this predetermined locus by e.g. stamping. In this manner, the fuse unit (1) can be manufactured easily at low costs, irrespective of the number and electric capacity of the fuse element portions (5).

Description: The present invention generally pertains to fuse units and their manufacturing method. It further relates to a fuse box, with a fuse cover, adapted to contain the fuse unit. Such a fuse box can be suitably used in vehicles, e.g. automobiles. Fig.1 shows an example of a known fuse box unit which is directly connectable to a battery. A fuse box unit 61 comprises a fuse box 62, flat fuses 63 and other components. The flat fuses 63 are formed by stamping out an electrically conductive metal plate or sheet. Each flat fuse 63 includes a fuse element portion 64 formed in a curved plane and interposed between two ear portions 65 having a respective ear hole for bolting. The fuse element portion 64 is fusible, and its width is set as a function of the current required to be passed. The fuse box 62 is made of a resin, and includes a plurality of enclosures 66 which can contain the corresponding number of flat fuses 63. A pair of flat nuts (first flat nut 67 and second flat nut 68) is insert-molded on the base of each enclosure 66. The first flat nut 67, which is used for power input, has a first flat nut hole for bolting. From this first flat nut 67 extends a terminal directly connectable to a battery (not shown in the figures). Accordingly, a flat fuse 63 is installed and a bolt 69 can be screwed into the ear hole and the first flat nut hole, so that a first end of the flat fuse 63 is connected and fixed to the first flat nut 67 at the power input side. Likewise, the second flat nut 68 has a second flat nut hole for bolting at a power output side. Accordingly, the flat fuse 63 is fixed by screwing down a bolt 69 into the second flat nut hole, so that the other end of the flat fuse 63 is connected to the second flat nut 68 at the power output side. Electrical cables 71 constituting a wire harness 70 are cramped respectively with an LA terminal 72. These LA terminals 72 are connected and fixed to the second flat nuts 68, together with the flat fuses 63, through the bolts 69. The fuse box 62 is then protected by placing a fuse cover 73 thereon. However, when a fuse element portion 64 is to be made narrower than a usual size, it tends to curve or bend, and the flat fuse 63 produced therefrom cannot be endowed with sufficient mechanical strength. Moreover, it is difficult to manufacture a flat fuse 63 having a small electrical current capacity. Further, assembling various components into a fuse box unit 61 requires cumbersome work steps, such as a step of fixing a plurality of flat fuses 63 into a fuse box 62 by means of bolts 69 and first and second flat nuts 67 and 68. As a consequence, the prior art fuse box unit has a quite low operation efficiency when mounted. Furthermore, a prior art fuse box unit 61 must sometimes be constructed by using flat fuses 63 having different current ratings. In such a case, fuse element portions 64 having different widths must be prepared as a function of their current capacity. As a result, several kinds of dies have to be used for stamping, incurring additional production costs. The present invention was contemplated in the light of the above problems. A first object of the invention is to provide a method of manufacturing a fuse unit in an easy and economical way, irrespective of the current capacity rating required and the number of fuse element portions. A second object of the invention is to provide a fuse unit which can be manufactured easily at a low cost according to the above method, which fuse unit is endowed with a sufficient mechanical strength and can be fixed easily into a fuse recipient, e.g. a fuse box. To this end, there is provided a method of forming a fuse unit comprising an electrically conductive plate including an input terminal, at least one output terminal and at least one fuse element portion linking the input terminal and the output terminal(s), the fuse unit further comprising a insulator material, the method comprising the steps of: stamping the electrically conductive plate so as to form the input terminal and the output terminal(s); providing at least one locus predetermined for forming the fuse element portion(s); molding all or part of an area including the locus/loci with the insulator material; and forming the fuse element portion(s) at the locus/loci. Preferably, the molding step comprises molding a part of the area, such that at least one non-shielded portion is formed for the locus/loci Suitably, the molding step comprises insert-molding a part of the area by means of a die including at least one protrusion, so that the protrusion(s) form(s) the non-shielded portion(s). Preferably yet, the stamping step comprises stamping the electrically conductive plate so as to form the input terminal, the output terminal(s) having a respective end portion, and at least one tie bar linking the end portion(s) of the output terminal(s); Further yet, the forming step may comprise stamping the locus/loci so as to yield the fuse element portion(s), whilst simultaneously removing the tie bar (s) by the stamping. The invention further relates to a fuse unit comprising an electrically conductive plate including an input terminal, at least one output terminal and at least one fuse element portion linking the input terminal and the output terminal(s), the fuse unit further comprising an area molded with an insulator material, the area including at least one opening, through which the fuse element portion(s) is/are exposed to outside the insulator material. The invention concerns also a fuse box containing a fuse unit, the fuse unit comprising an electrically conductive plate including an input terminal, at least one output terminal and at least one fuse element portion linking the input terminal and the output terminal(s), the fuse unit further comprising an area molded with an insulator material, the area including at least one opening, through which the fuse element portion(s) is/are exposed to outside the insulator material; the fuse box forming a hollow cylindrical shape having a substantially rectangular cross-section, and a top opening and a bottom opening, the fuse box containing at least one partition wall extending in the longitudinal direction of the cylindrical shape, thereby forming several enclosures lodging the output terminal(s), the partition wall(s) including a slit extending from the top opening to half-way downwards in the longitudinal direction, the slit(s) lodging the insulator material such that the input terminal extends perpendicularly to the longitudinal direction from the top opening. The fuse box may further comprise a fuse cover including a cover plate and a cover joint, the cover plate covering the input terminal of the fuse unit and the cover joint covering the top opening of the fuse box. In the first aspect of the invention, when the fuse element portion is being built, the peripheral area around it is already reinforced by the insulator material. Accordingly, even when a thin fuse element portion must be formed, the stress, which may cause curving or bending of the fuse element, is hardly exerted towards the fuse element portion. The fuse element portion can thus be rendered less liable to deformation or breaking, and is secured with sufficient strength. Further, even when the fuse element portion must be given a small electrical current rating, it can be formed relatively easily. Further yet, several fuse element portions having a different thickness can be formed using only one kind of die. Costs incurred for die preparation can thus be reduced to minimum, and the fuse units can thus be produced at low cost. In a second aspect of the invention, the end portions of the output terminals are linked to each other by tie bars. By virtue of this configuration, the relative positions of the output terminals are kept constant, up to a moment when the fuse element portions are formed by stamping. Further, it is more difficult to exert curving- or bending-inducing stress on the fuse element portion. As a result, the fuse element portion is securely prevented from deformation or breaking. Further, the tie bars are removed by stamping at the same time as the fuse element portion is formed. The number of operation steps, as a whole, can thus be kept to a minimum, leading to improved production efficiency. When the loci exposing through the window portions are stamped out, the insulator material does not impede the stamping work. The latter is thus facilitated greatly. In such a case, even when the insulator material used is not sufficiently elastic, the generation of cracks is nonetheless prevented. In a third aspect of the invention, as the fuse element portion is exposed through the window portion, the former can be inspected visually, irrespective of the insulator material used. Moreover, such a fuse unit can be constructed easily and economically when the above-mentioned method is applied. The above and the other objects, features and advantages of the present invention will be made apparent from the following description of the preferred embodiments, given as non-limiting examples, with reference to the accompanying drawings, in which: Fig.1 is a perspective view of a disassembled fuse box known in the prior art; Figs.2 (a), (b), (c) and (d) are, respectively, a top plan view, a front elevational view, a side elevational view and a rear elevational view of a fuse unit according to the present invention; Figs.3 (a), (b) and (c) are, respectively, front elevational views of the inventive fuse unit, explaining how the fuse unit is manufactured; Figs.4 (a), (b), (c) and (d) are, respectively, a top plan view, a front elevational view, a side elevational view and a rear elevational view of a fuse box according to the present invention; Figs.5 (a), (b) and (c) are views facing arrow directions along, respectively, on a cross-section along line A-A of the fuse box of Fig.4 (a), a cross-section along line B-B of the fuse box of Fig.4, and a cross-section along line C-C of the fuse box of Fig.4 (b); Figs.6 (a), (b), (c), (d) and (e) show a fuse cover, seen respectively from, a top plan view, a front elevational view, a cross-sectional view along line D-D of Fig.6 (b), a side elevational view and a rear elevational view; Fig.7 is a view of the base face of the fuse cover of Fig.6; and Figs.8 (a); (b) and (c) are views of the fuse unit when contained in the fuse box, shown respectively by, a top plan view, a front elevational view and a side elevational view. Figs.2 to 8 show a fuse unit 1 used in automobiles, according to an embodiment of the present invention. As shown in Fig.2, the fuse unit 1 is formed by incorporating an electrically conductive plate 2, e.g. a metal plate. The latter 2 includes e.g. a material made of silver, copper, zinc, tin, lead, or an alloy made with at least one of these metals. The conductive metal plate 2 is then formed into an input terminal 3, one or several output terminals 4 (also known as "male tabs 4") and one or several fuse element portions 5. The input terminal 3 can be directly connected to a power-supply terminal for a battery mounted in an automobile (not shown in the figures). This input terminal can therefore be qualified as a terminal directly connectable to a battery. An input terminal 3 comprises a first strip portion 3a (usually placed upright during use), and a second strip portion 3b (usually placed horizontally during use) which is narrower than the first strip portion 3a and arranged perpendicular thereto. A first end (left-hand side in Fig.2 (c)) of the second strip portion 3b is linked to a first end (top side in Fig.2 (c)) of the first strip portion 3a. The second strip portion 3b is configured so as to form a cross-section having an inverted U-shape (see top portion of Fig.2 (d)). A through hole 6 for bolt insertion is provided in the second strip portion 3b. It is placed at a half-way point widthwise and near a second end of the second strip portion 3b, distal to the first end thereof (see Fig.2 (a), in which the second strip portion 3b is shown in the upright position). The input terminal 3 is fixed to the power-supply terminal by fitting a bolt into the through hole 6 and a nut. The fuse unit 1 according to the present embodiment includes several units of male tabs 4 and corresponding fuse element portions 5. An example of the invention shown in Fig.2 contains four such units. Each fuse element portion 5 contained in the corresponding fuse unit 1 is made substantially narrower than the male tab 4, and wound into substantially a S-shaped configuration. A first end of each fuse element portion 5 leads to the first end of the second strip portion 3b. A second end of the fuse element portion 5 leads to a first end (upper end in Fig.2 (b)) of the male tab 4, which extends in a vertical direction in the same figure. The input terminal 3 is thus connected to each male tab 4 through each fuse element portion 5. A peripheral area of the fuse element portion 5 including the latter (which is formed in the conductive metal plate 2) is molded with an insulator resin. Such a peripheral area covers the first strip portion 3a as a whole, and a top end portion of the male tab 4. The molded resin portion 7 thus produced forms a thin plate. Typically, such an insulator resin includes an epoxy resin. The molded resin portion 7 includes four window portions 8 at predetermined positions. The window portions 8 have a substantially square shape, as shown in Fig.2. Through these window portion 8 is exposed each fuse element portion 5 to the outside, beyond the molded resin portion 7. The fuse unit 1 of the present embodiment shown in Fig.2 is therefore in the form of a rake or fork. In this embodiment, one input terminal 3 branches into four male tabs 4. The fuse unit 1 is manufactured according to the steps shown in Fig.3 (a), (b) and (c). First, there is provided an initial electrically conductive plate 2. The conductive plate 2 is then stamped out to yield, integrally, an input terminal 3, four male tabs 4 and corresponding tie bars 11. The tie bars 11 may have the same thickness as the conductive metal plate 2, but they may also be made thinner by, for example, half-etching. Preferably, each tie bar 11 is formed at a position uncovered by the molded resin portion 7, i.e. at a lower end portion of the male tab 4. Further, a through hole 6 for bolting (see Fig.2 (a)) may be formed at the same time as the metal plate 2 is stamped out. The transformed conductive plate 2 is then bent into a piece having a side cross-section of substantially L-shaped configuration, using a specific bending tool. An area including loci intended for subsequently lodging fuse element portions 5 (fuse-forming loci 12) is insert-molded in a suitable way with an insulator resin, so as to form a molded resin portion 7. In a preferred embodiment, the insert-molding is effected such as to form window portions 8. In such a case, only the fuse-forming loci 12, intended for lodging the fuse element portions 5, are exposed to the outside through the window portions 8. In order to reserve room for window portions 8 in the molded resin portion 7, the insert-molding die may be provided e.g. with a convexity corresponding to the window portions 8. The exposed fuse-forming loci 12 are then formed into four fuse element portions 5 by stamping, whilst three tie bars 11 are removed by the same stamping operation. The male tabs 4 are thus separated from each other to form a desired fuse unit 1 shown in Fig.2. The fuse unit 1 thus produced is inserted into a fuse box 21 shown in Fig.4, prior to use. The fuse box 21 has a rectangular tubular shape, with top and bottom ends open. A top opening 22 and a bottom opening 24 thus have a rectangular surface, respectively. The outside rim portion of the top opening 22 is provided with a plurality of stopper means 27 and a flat fixture portion 28. The inside space of the fuse box 21 is separated into four enclosures by three insulator partition walls 23. The top and bottom openings 22 and 24 of the fuse box 21 are therefore defined by four square areas. The four enclosures form four spaces for containing terminals (not shown in the figures) to be press-fitted to an electrical cable. Preferably, a portion of the inner face of fuse box 21, which inner face defines each of the four enclosures, is provided with a lance structure in order to hang the terminal therein. The other end of the terminal is press-fitted with a corresponding electrical cable which will constitute a wire harness. A top portion of each partition wall 23 is provided with a slit 25 which extends vertically from the top to a point half-way downwards. The slits 25 have the same width for all the enclosures. The width of the slit 25 correspond to the thickness of the molded resin portion 7 of the fuse unit 1, so that the fuse unit 1 is fixed in the fuse box 21 by inserting the molded resin portion 7 into the slit 25 (see Fig.8). Two opposing positions on the smaller inner surfaces of the fuse box 21, which correspond to the cross points with a plane passing through the slits 25, are provided with a pair of guiding ribs 26, respectively. The two guiding ribs 26 of the same pair extend in parallel to each other, from top of the fuse box 21 to a point half-way downwards. The distance between the two guiding ribs 26 is arranged to correspond substantially to the thickness of the molded resin portion 7 of the fuse unit 1. Accordingly, when the fuse unit 1 is put into the fuse box 21, the two end rims of the molded resin portion 7 are held by the two pairs of guiding ribs 26 (see Fig.8 (a)). Figs.6 and 7 show a fuse cover 41 for protecting the fuse unit 1. The fuse cover 41 is made of an insulator material, e.g. a resin. The fuse cover 41 comprises a cover plate 42, a cover joint 43 and a hinge portion 44 combining them. The cover plate 42 covers and protects the power-supply terminal for a battery mounted e.g. in an automobile. The outer side face of the top of the cover plate 42 is marked with an indication to caution that it encloses a power-supply terminal. The cover joint 43 is mounted so as to close the top opening 22 of the fuse box 21. The cover joint 43 carries integrally formed hooking means 45 at positions corresponding to those of the stopper means 27. Accordingly, when the fuse cover 41 is placed on the fuse box 21, the hooking means 45 are hooked to the stopper means 27. The cover joint 43 is thus securely fixed onto the top opening 22 of the fuse box 21. There are provided two pairs of cover guiding ribs 46 on the rear face the cover joint 43. The distance between the cover guiding ribs 46 is designed to be substantially the same as the thickness of the molded resin portion 7 of the fuse unit 1. Accordingly, when the fuse unit 1 is installed and the fuse cover 41 is mounted, two end rims of the molded resin portion 7 are held by the two pairs of cover guiding ribs 46. According to a manufacturing method of the invention, when the fuse element portions 5 are formed, the peripheral area of the element-forming loci 12 (intended to form the fuse element portions 5) is already reinforced with a molded resin portion 7. By virtue of this structure, even when narrow fuse element portions 5 are to be formed, they are less susceptible to stress which may otherwise cause curving or bending of the fuse elements. In other words, the fuse element portions 5 are more resistant to deformation or breaking, and maintain an appropriate strength during their manufacture. As a result, the fuse unit 1, however small their electric capacity is, can be manufactured relatively easily. According to the method of the invention, four fuse element portions 5 having different widths can be formed easily through one stamping die only. Costs incurred for preparing dies can thus be reduced to a minimum. As a consequence, the fuse units 1 and the entire assemblies containing these fuse units 1 can be produced at low costs. According to the present manufacturing method, the end portions of adjacent male tabs 4 are initially linked to each other by tie bars 11. The structurally strengthening effect of this construction ensures that the mutual positions of the male tabs 4 are properly maintained, up to a moment when the fuse element portions 5 are formed by stamping. In addition, as mentioned above, the fuse element portions 5 are protected from stress which may cause a curving or bending of the fuse elements. The fuse element portions 5 are thus less prone to deformation and breaking. As has been understood from the above, the tie bars 11 are removed at the same time as the fuse element portions 5 are formed. The presence of the tie bars 11 does therefore not increase the operation steps as a whole, while enabling the fuses units 1 to be manufactured easily and efficiently. Furthermore, since the stamping operation is effected on the loci exposed through the window portions 8, the molded resin portion 7 does not impede such operation. The fuse element portions 5 can thus be formed very easily. In the past, a plurality of individually manufactured fuse elements were fixed to a fuse unit. By comparison, according to the inventive fuse unit 1, four male tabs 4 and four fuse element portions 5 are formed in the same piece of conductive metal plate 2. This construction obviates the need for a number of nuts and bolts, classically used for fixing the fuse element portions into a fuse unit 1, as well as for fixing the fuse unit 1 into a fuse box 21. Operators are thus freed from tedious operations of screwing bolts into nuts. In addition, fixing the fuse unit 1 into the fuse box 21 can be done much more easily than in the past. In the inventive fuse unit 1, the peripheral area of the fuse element portions 5, which tends to be mechanically weak, is protected by a molded resin portion 7, so that the fuse unit 1 procures by itself a sufficient mechanical strength. In such construction, even if the fuse element portions 5 are rendered thin and narrow, they are not made susceptible of deformation as such. Furthermore, the presence of the molded resin portion 7 makes the fuse unit 1 more waterproof. Further, in the fuse unit 1 of the invention, the fuse element portion 5 is constantly exposed to the outside through the window portion 8. The fuse element portion 5 can thus be inspected visually, irrespective of the material used for the molded resin portion 7. For example, when the fuse element portion 5 is fused by the passage of an excessive current, this condition is easily detected by an human eye. The structure of the fuse unit 1 may be modified very easily, so as to produce various embodiments as follows. The number of male tabs 4 used as output terminals is not limited to four, exemplified in the above embodiment. It may be one, two or three. It may also be more than four. The form of male tabs 4 may also be modified as desired. Likewise, the input terminal 3 may have a configuration other than the one described above, or may not include the through hole 6 for bolting. When only one male tab 4 is provided, the number of fuse element portions 5 may also be reduced to one. The insulator material used is not limited to the above-mentioned molded resin portion 7, but may be e.g. rubber. Likewise, the insulator material may be formed according to a method other than the insert-molding. When a rubber is used as insulator material, the fuse element portion 5 can be formed by stamping, without forming the window portion 8. One reason for allowing such a formation step is that, as the rubber is a good elastic material, there forms little stress inside the rubber, and consequently no crack will be formed through such operation. As mentioned above, the tie bars 11 is removed at the same time as the fuse element portion 5 is formed by stamping. But they may also be eliminated in a separate process. Moreover, when the fuse element portion 5 risks no deformation or breaking-up, the use of tie bars 11 may not be required. Instead of stamping, the fuse element portion 5 may also be formed by e.g. etching. The window portion 8 may be in a form other than a rectangular form, e.g. a circular or triangular form. The window portion 8 may also be one single large unit including a plurality of fuse-forming loci 12, thereby forming one common window portion 8. Further advantages of the present invention will be made apparent from the following description of the technical concepts on which the present invention is based. Firstly, the input terminal of the present invention can be connected directly to a power-supply terminal of batteries. Secondly, the input terminal of the invention can be used for the power-supply terminal for batteries in an automobile. Thirdly, each of the output terminals may be in the form of a male tab, which can be connected to a press-fixing terminal provided in a wire harness. According to this construction, the fuse unit can be connected to a wire harness in a very secured way. Fourthly, the fuse unit can be substantially in the shape of a rake or fork. Fifthly, the input terminal may be provided with a bolt hole, which may not be covered with the insulator material. By fixing with bolts, the input terminal can be fixed to the power-supply means in a more secured manner. . Sixthly, the tie bars may be rendered thinner than the electrically conductive plate. The tie bars are thus very easily stamped away. Seventhly, the tie bars are formed outside the area where the insulator material is coated. Eighthly, the input terminal and the output terminals are first formed in the electrically conductive plate. An area of the conductive plate including the loci, where the fuse element portions are formed later, is then molded with an insulator material. These loci for fuse element are subsequently transformed into fuse element portions. Accordingly, irrespective of their width, the fuse element portions can be formed at a predetermined position, in an easy and economical way. Ninthly, an area portion of the electrically conductive plate (which may include an input terminal, several output terminals and several fuse element portions linking them) is molded with an insulator material. In addition, the insulator material is provided with window portions, through which the fuse element portions are exposed to the outside. This fuse unit can be constructed easily and at a low cost. Further, the fuse unit obtained procures a sufficient mechanical strength, and can be easily mounted into a fuse box. Furthermore, the fuse element portions can be inspected by direct observation. A main advantage of the invention is that the fuse unit is manufactured in a easy and economical way, irrespective of the current capacity and number of the fuse element portions. A further advantage consists in the fact that the fuse element portions are protected from deformation or breaking while manufacturing the fuse unit. Another advantage is that, in a preferred embodiment, the fuse element portions can be inspected through a direct eye observation.

Claims: A method of forming a fuse unit (1) comprising an electrically conductive plate (2) including an input terminal (3), at least one output terminal (4) and at least one fuse element portion (5) linking the input terminal (3) and the output terminal(s) (4), the fuse unit further comprising an insulator material (7), characterised in that said method comprises the steps of: a) stamping said electrically conductive plate (2) so as to form said input terminal (3) and said output terminal(s) (4); b) providing at least one locus (12) predetermined for forming said fuse element portion(s) (5); c) molding at least an area of the plate including said locus/loci with said insulator material (7); and d) forming said fuse element portion(s) (5) in said locus/loci (12). The method according to claim 1, wherein said molding step is effected to form a window portion(s) (8) formed over said locus/loci. The method according to claim 2, wherein said molding step comprises insert-molding a part of said area by means of a die including at least one convexity corresponding to said window portion(s) (8). The method according to any one of claims 1 to 3, wherein said stamping step moreover additionally forms at least one tie bar (11) linking said end portion(s) of said output terminal(s) (4). The method according to claims 1-4, wherein. said forming step comprises stamping said locus/loci so as to yield said fuse element portion(s) (5), whilst simultaneously removing said tie bar (s) (11) by said stamping. A fuse unit (1) comprising an electrically conductive plate (2) including an input terminal (3), at least one output terminal (4) and at least one fuse element portion (5) linking said input terminal (3) and said output terminal(s) (4), characterised in that said fuse unit (1) further comprises an area molded with an insulator material (7), said area at least one including window portion (8), through which said fuse element portion(s) (5) is/are exposed to outside of said insulator material (7). A fuse box (21) containing a fuse unit according to claim 6 (1), said fuse box (21) forming a hollow cylindrical shape having a substantially rectangular cross-section, and a top opening (22) and a bottom opening (24), said fuse box (21) contains at least one partition wall (23) extending in the longitudinal direction of said cylindrical shape, thereby forming several enclosures lodging said output terminal(s) (4), said partition wall(s) (23) include(s) a slit (25) extending from said top opening (22) to a point half-way downwards in said longitudinal direction, and said slit(s) (25) lodge(s) said insulator material (7) such that said input terminal (3) extends perpendicularly to said longitudinal direction from said top opening (22). The fuse box (21) according to claim 7, further comprising a fuse cover (41) including a cover plate (42) and a cover joint (43), said cover plate covering said input terminal (3) of said fuse unit (1) and said cover joint (43) covering said top opening (22) of said fuse box (21).

Inventors: SUMIDA TATSUYA, TAGA SHUNJI, SUMIDA, TATSUYA, TAGA, SHUNJI, Sumida, Tatsuya, c/o Sumitomo Wiring Syst., Ltd., Taga, Shunji, c/o Sumitomo Wiring Syst., Ltd.
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 2000
Main classification: H01H85
IPC codes: H01H85, H01H69