Plug for connection strips and method for the production thereof

[0001] The invention relates to a plug for terminal blocks of telecommunications and data systems equipment and a method for its production.

[0002] Terminal blocks for telecommunications and data systems equipment typically comprise a first row of contact elements for connecting incoming wires and a second row of contact elements for connecting outgoing wires. Arranged between the assigned contact elements of the first and second rows are tapping contacts, into which measuring, test and protective plugs can be inserted. The tapping contacts are designed as connecting or disconnecting contacts. The known test and protective plugs are symmetrically constructed, with the housing of the plug covering the contact elements of the first and second rows of contact elements, so that they are not accessible for activation purposes. If the fitted connecting cord of the measuring or test plug happens to be a temporary patch connection and if the temporary patch connection is to be replaced by permanent jumpering, the subscriber connection must first be disconnected by removing the plug before the permanent jumpering can take place.

[0003] A further problem is that, when inserting a measuring, protective or test plug, an already existing connection should not be interrupted, since this would otherwise lead to data losses.

[0004] DE 34 46 622 A1 discloses a plug insert of a plug for a terminal block, the one-part plug insert comprising a plurality of punched parts that are electrically isolated from one another and form the interconnects, which are encapsulated in a plastic and are consequently embedded in the plastic. The punched parts are preferably formed such that they widen in the region of insertion. This ensures that the plug can be plugged in and pulled out without causing an interruption. A disadvantage of the known plugs is their relatively complex production.

[0005] Furthermore, there are known protective plugs for terminal blocks which can be inserted into connecting or disconnecting contacts of a terminal block and are unsymmetrically formed. These plugs substantially comprise an upper housing part and a printed circuit board, which at the same time closes the housing. As a result, the contact elements assigned to subscribers are freely accessible for a placement tool even when the protective plug is inserted. However, owing to the choice of the printed circuit board as the contact element, these plugs have the disadvantage that they cannot be inserted without causing an interruption on account of the circuit board contour with no edge metallization.

[0006] The invention is therefore based on the technical problem of providing a plug for terminal blocks in telecommunications and data systems equipment which is simple to produce and allows interruption-free insertion in a tapping contact of a terminal block, and also of providing an associated production method.

[0007] For this purpose, the plug comprises a lower part and an upper part of plastic, which are interconnected, the lower part being made longer than the upper part, with the lower part having galvanically metallized structures, which form at least the contact element and extend as far as the lower edge of the lower part. This allows the contact element to contact the tapping contact without causing an interruption. On account of the unsymmetrical form of the plug, the contact elements assigned to the subscribers are also freely accessible when the plug is inserted, so that jumpering can be carried out with the plug inserted, without interrupting a patch connection that has possibly an already been set up.

[0008] The metallic structures forming the contact elements and/or the lower part preferably have on the lower edge a small bevel, so that the introduction of the contact element is improved, so that interruption-free contacting operation is further improved, since the contact element and the tapping contact are already in contact before the contact springs are mechanically bent apart.

[0009] In a further preferred embodiment, the metallic structures additionally comprise interconnects and/or terminal elements for a printed circuit board.

[0010] The terminal elements for the printed circuit board are preferably formed as metallized cylinders which engage in metallized holes of a printed circuit board and contact the latter. Then, according to requirements, various components and/or functional groups can be arranged on the printed circuit board.

[0011] The printed circuit board is in this case preferably arranged in the overlapping region of the upper part and lower part, so that it is protected against physical contact and mechanical impact.

[0012] In a further preferred embodiment, the length of the lower part and upper part is chosen such that, in the inserted state, the contacts of the terminal block that are facing the lower part are accessible for a placement tool.

[0020] In FIGS. 1 and 2, a plan view and a bottom view of a lower part 1 with a galvanic link 2 are perspectively represented. The lower part 1 is in this case made up as one piece by a basic body 3 and a core part 4 to be metallized. The core part 4 comprises metallized structures, which are formed as contact elements 5, interconnects 6 and terminal elements 7 and are galvanically reinforced. For this purpose, for example, the lower part 1 is produced in a two-shot injection-molding process, with a metallizable, pretreated plastic being injected by means of the first shot and the basic body 3 being molded by means of the second shot, with the later contact elements 5, interconnects 6 and terminal elements 7 remaining free. On these exposed surfaces, a basic metallization is built up in a chemical process. Subsequently, the lower part 1 is attached by means of the electrically conducting galvanic link 2 to a supporting frame, which is connected to a voltage source, whereas the lower part 1 is immersed in an electrolytic bath in which the counterelectrode is located. During the subsequent flow of current, metal is then deposited at the locations at which the base metallization previously took place, with only the surfaces which are connected in an electrically conducting manner to the supporting frame being reinforced. Subsequently, the galvanic link 2 can be removed from the lower part 1. In FIG. 1, the lower part 1 after galvanizing is represented, with six contact elements 5 having been respectively deposited on the upper side and lower side of the lower part 1 for a 12-pin plug. The contact elements 5 are then connected via the interconnects 6 to the terminal elements 7, which are formed as metallized cylinder pins. The contact elements 5 and the lower edge 9 of the lower part 1 are slightly beveled in each case. For better connection of the galvanic link 2 to the supporting frame (not represented), said link is formed with matching clearances 10.

[0021] Depending on the intended use of the plug, the contact elements on the upper side and underside can be interconnected by metallized drill holes 8.1 to 8.6. In the embodiment represented for connecting up two shielded twin wires, the contact elements 5.1 and 5.2 assigned to the shieldings are interconnected on the upper side with the associated contact elements 5.7 and 5.10, on the underside by the drill holes 8.1 and 8.4 and are connected to the common terminal elements 7 via the interconnects 6.1 or 6.4, respectively. The remaining contact elements 5.2, 5.3, 5.5, 5.6, 5.8, 5.9, 5.11 and 5.12, on the other hand, are led separately to a terminal element 7 of their own, so that the separation of the potentials into the system side and the subscriber side allows measurement to be carried out. For this purpose, the potentials of the contact elements 5.8, 5.9, 5.11 and 5.12 are led through the plated-through drill holes 8.2 and 8.3 or 8.5 and 8.6, respectively, to the upper side of the lower part 1, where the electrical connection to the terminal elements 7 is then established via interconnects 6. For reasons of clarity, the index on the contact elements 5, the drill holes 8 and interconnects 6 is omitted hereafter.

[0022] In FIGS. 3 and 4, the fully assembled plug 11 is respectively represented. Along with the already described lower part 1, the plug 11 comprises an upper part 12, which is made shorter than the lower part 1. The upper part 12 is in this case connected to the basic body 3 of the lower part 1. Before the upper part 12 and lower part 1 are put together, a printed circuit board 13, which can be seen in FIG. 3.through the depicted aperture in the upper part 12, is fitted into the lower part 1. The printed circuit board 13 is formed with metallized holes, through which the terminal elements 7 are led. As a result, the printed circuit board 13 is electrically connected to the contact elements 5. On the printed circuit board 13, functional modules 14 are arranged and leads 15 of a patch cable 16 are soldered. The printed circuit board 13 is then completely protected by the upper part 12 and the basic body 3 of the lower part 1. The remaining webs 17 of the removed galvanic link no longer have any functional purpose, but they are useful as an aid for introducing the plug 11 into the tapping contacts of the terminal block.

[0023] In FIGS. 5 and 6, the inserted plug 11 in the terminal block 18 is represented. Furthermore, a placement tool 19 for jumpering a wire 12 has been put in place. On account of the unsymmetrical form of the plug 11 and the length of the upper part 12, the contacts of the terminal block 18 that are facing the lower part 1 are freely accessible and can be connected up to a wire 20. For this purpose, an activating blade 21 of the placement tool 19 presses the wire 20 into an insulation-displacement contact, where it then forms an electrical connection.

• [0024] 1 lower part
• [0025] 2 link
• [0026] 3 basic body
• [0027] 4 core part
• [0028] 5.1 to 5.12 contact element
• [0029] 6 interconnects
• [0030] 7 terminal elements
• [0031] 8.1 to 8.6 drill holes
• [0032] 9 edge
• [0033] 10 clearances
• [0034] 11 plug
• [0035] 12 upper part
• [0036] 13 printed circuit board
• [0037] 14 functional elements
• [0038] 15 leads
• [0039] 16 patch cable
• [0040] 17 webs
• [0041] 18 terminal block
• [0042] 19 placement tool
• [0043] 20 wire
• [0044] 21 activating blade