GB2283619A

GB2283619A - Shielded connection box and shielded connector

Info

Publication number: GB2283619A
Application number: GB9413540A
Authority: GB
Inventors: Gerd Philipp
Original assignee: Telegaertner Karl Gaertner GmbH
Current assignee: Telegaertner Karl Gaertner GmbH
Priority date: 1993-09-14
Filing date: 1994-07-05
Publication date: 1995-05-10
Anticipated expiration: 2014-07-05
Also published as: PL304444A1; FR2710198B1; CZ158994A3; SK113394A3; JPH07231537A; GB2283619B; AU6868094A; ZA944558B; ES2106659B1; FR2710198A1; SE9402963D0; SE9402963L; FI944206A0; AT406809B; ES2106659A1; HUT68195A; SE508848C2; DK104794A; GB9413540D0; CZ275895A3

Abstract

As connecting device for a data network, a connecting box (15) contains a circuit board by means of which two BNC sockets (16, 17) and at least one switched socket (18) are connected to one another. In order as far as possible not to interrupt the coaxial system of the data network in the region of the connecting box (15), the circuit board is constructed as a multilayer board, with the conductor tracks (43) extending between two shielding conductor surfaces (41, 42). The switched socket (18) is surrounded for the same purpose by a tightly fitting screening plate (44). In the case of the associated connecting cable, the plug-in part (24) of the plug (23) is likewise surrounded by a screening plate (46), with the result that the coax-like conductor guidance is continued here, as well. The connecting device therefore reliably meets the transmission requirements, such as immunity to radiated interference and low signal distortion. <IMAGE>

Description

Connecting box and connecting cable for forming a connecting device for a data network The invention relates to a connecting box in accordance with the preamble of Claim 1, and to a connecting cable in accordance with the preamble of Claim 9.

Both objects are disclosed, for example, in German Utility Model 90 00 754. The main purpose of a data network is to interconnect a plurality of data processing devices or to connect them to a central computer or the like. To this end, a screened cable (coaxial cable) in the course of which a plurality of connection boxes are provided is permanently installed, so that it is possible, depending on need, for devices to be connected by means of suitable connecting cables at various points in a room or an entire building. The advantage of the functional plug sockets actually developed for telephone connecting boxes resides in that the data network is never interrupted, regardless of whether a connecting cable is plugged in or not by means of its functional plug. It is thus impossible for an error to be caused by inattentiveness. The disadvantage resides in that the overriding transmission requirements, such as immunity to radiated noise, for such data networks can be met only at the boundary of the tolerable frame. The reason for this is that the coaxial system is interrupted in the region of the connecting boxes and functional plugs. It is known from the abovenamed utility model to provide particular screening for the conductor tracks on the circuit board in the connecting box by means of a large copper surface located opposite.

There is also a connecting box of comparable type whose housing was constructed as a zinc die-cast moulding. Likewise, the functional plug of the connecting cable was enclosed in a zinc die-cast moulding. Although encapsulation constructed in such a way prevents incoming and outgoing radiated interference, a coaxial system remains interrupted nevertheless, resulting in transmission losses and signal distortion at the limit of that which is permissible. In addition, this complete encapsulation is very expensive and it is desirable in some applications for no earthed metal parts to be freely accessible, in order to prevent spark discharges in the event of electrostatic charges.

The object of the invention is to provide a connecting box according to the preamble and a connecting cable which matches it, by means of which it is possible to meet the transmission requirements in a cost-effective way which is safer and more reliable in terms of series production.

This object is achieved with respect to the connecting box by means of the characterizing features of Claim 1, and with respect to the connecting cable by means of the characterizing features of Claim 9.

The conductor tracks on the circuit board are enclosed on both sides by screening surfaces, with the result that a situation similar to the coaxial cable arises here. The screening plates laid individually and closely around the functional plug sockets are situated at a distance from the switching contact tongues such as is characteristic of a coaxial system. The screening plate also encloses the plug-in part of the functional plug in a corresponding way. It goes without saying that the screening plates of the functional plug socket and functional plug likewise engage in one another like a plug and socket. The coaxial system of the data network is therefore continued as far as possible in the region of the connecting points, as well. The system is insulated from the outside, it being possible for the connecting box to be constructed with a plastic housing in the manner customary to date. The connecting boxes are also compatible with non-screened functional plugs.

Further advantages and refinements of the invention are yielded by the subclaims and the following description of exemplary embodiments with the aid of the drawing, in which: Figure 1 shows the electric circuit with the dia grammatically indicated screening in accordance with the invention, Figure 2 shows a cross-section through a section of the circuit board in accordance with the invention, Figure 3 shows a side view of a flush-type connecting box in accordance with the invention, with some parts indicated only diagrammatically, Figure 4 shows a perspective representation of a functional plug socket with a screening plate in the separated state before installation, Figure 5 shows a side view of a functional plug in accordance with the invention, with the upper housing half removed, and Figure 6 shows a sectional view of the socket and plug shortly before the plugged-in state, the part to the right of the centre plane corresponding to the section in the plane 6r-6r of Figure 5, and the left-hand part corresponding to the section in the plane 61-61 of Figure 5.

The circuit diagram in accordance with Figure 1 shows an incoming data bus 11 which is connected to a BNC plug 12. The outgoing data bus 13 is connected to a further BNC plug 14. Located therebetween is a connecting box 15, which is represented here only diagrammatically and firstly has two BNC sockets 16 and 17 for connection of the BNC plugs 12 and 14. It contains furthermore two functional plug sockets 18 and 19. The functional plug socket 18 or 19 (the two are identical) has a first pair of switching contact tongues having two switching contact tongues 21, 22 which are oppositely situated in pairs and touch one another in an electrically conductive fashion when no functional plug is plugged in, as represented in the case of the functional plug socket 19. If, however, a functional plug 23 is plugged in, as shown in the lefthand functional plug socket 18, the switching contact tongues 21, 22 are separated from one another.

The functional plug 23 has a first pair of contact tongues with contact tongues 25 and 26 which are arranged in pairs on opposite outer sides of a plug-in part 24 and to which a signal line 27, 28 is respectively connected. These signal lines 27, 28 are insulated with respect to one another and electrically screened. Their other ends are jointly connected to the central control pin 29 of a BNC plug 31. Together with the functional plug 23 and BNC plug 31, the two signal lines 27, 28 form a prepared duplex connecting cable 32 which is used to connect a data processing device 33 to the data network.

The signal path runs in this case from the data bus 11 via the central control pin 34 of the BNC plug 12 to the central contact tube 35 of the BNC socket 16, from there to the switching contact tongue 21 of the functional plug socket 18 and via the contact tongue 25 of the functional plug 23 and the signal line 27 to the central contact pin 29 of the BNC plug 31. Here, the signal path branches, on the one hand, to the data processing device 33 and, on the other hand, further via the signal line 28 back to the contact tongue 26, leads from there via the switching contact tongue 22 of the functional plug socket 18 and via the mutually contacting switching contact tongues 21, 22 of the functional plug socket 19 to the central contact sleeve 36 of the BNC socket 17, from where the signal path finally leads further into the outgoing data bus 13 via the central contact pin 37 of the BNC plug 14.

It is not shown in Figure 1 that each functional plug socket 18, 19 has a second pair of contact tongues in a plane below the represented switching contact tongues 21, 22, which need have no switching function and are electrically connected to the screens 38 of the BNC sockets 16, 17. The functional plug 23 also correspondingly has a second pair of contact tongues which is connected in parallel with the screens 39 of the signal lines and is electrically connected to the screens 38 via the second pair of contact tongues of the functional plug socket.

It is, furthermore, not shown in Figure 1 that each functional plug socket 18, 19 advantageously also has a further pair of switching contact tongues in a plane above the represented pair of switching contact tongues, which is connected electrically in parallel therewith. The functional plug 23 also correspondingly has yet another pair of contact tongues. Thus, should the contact suffer at a point, the respective parallel contact ensures future functioning.

Indicated diagrammatically in Figure 1 are a first conductor surface 41 and a second conductor surface 41 on either side of the conductor tracks 43 of a circuit board, as well as screening plates 44 and 45 in the region of the functional plug sockets 18, 19, which are all connected to the screen 38. The functional plug 23 is also sheathed with a screening plate 46, which is electrically connected to the screen 39.

Figure 2 shows a diagrammatic cross-section through a subregion of a circuit board 47 constructed as a multilayer board. The conductor tracks 43 are applied to a first flat side 48 of the base board 49, and the first conductor surface 41 is located on the second flat side 51. Located over the first flat side 48 is an insulating support 52 on the outer flat side 53 of which the second conductor surface 42 is constructed. The two conductor surfaces 41, 42, which extend over a large area of the entire surface of the board, have cut-out islands in the region of which through-plating 54 to the internal conductor tracks is performed in each case. Conversely, the inner conductor tracks bypass the through-plating 55, which makes a connection between the two outer layers.

Figure 3 illustrates the general design of the connecting box 15. The circuit board 47 is fitted on its top side with at least one functional plug socket 18, and the BNC sockets 16, 17, which are constructed as angled plug sockets, project away from its underside. The circuit board 47 is mounted in a bipartite plastic housing 60 which consists of a plate-like base part 56 and a cap part 57. The base part 56 has openings 58 for the passage of the connecting base 59 of the BNC sockets 16, 17. A metal mounting ring 61, which is used for the purpose of anchoring in a wall box 62, is firmly connected to the plastic housing 60. Located on the top is a cover plate 63 which also clamps in a cover 64 of large outline. The functional plug socket 18 is surrounded by a screening plate 44 on three sides, as may better be seen from the representation of Figure 4.

In accordance with Figure 4, the functional plug socket 18 has a prismatic plastic housing 66 with two mutually parallel larger flat sides 67, 68 and two narrow sides 69, 71 aligned at a right angle thereto. The top side has a plug-in opening for a corresponding functional plug, and the switching contact tongues may be seen which project into the interior and whose soldering lugs project out of the plastic housing 66 at the bottom. The screening plate 44 is bent approximately in the shape of a U and has two large-area side limbs 72, 73 which are applied directly to the flat sides 67, 68, and a transverse limb 74 which is applied to the narrow side 69. The limbs each further have on the top an inwardly angled web 75 which somewhat overlaps the top side of the plastic housing. The web 75 has a stiffening effect. The screening plate 44 has a plurality of soldering lugs 76, integrally formed thereon, which project downwards.

Stamped out regions approximately in the shape of a E produce in the limbs lamellae 77 which in each case bulge outwards somewhat from the plastic housing. They serve the purpose of resilient contact with a screening sheath of a functional plug, as will further be shown below.

Due to the U-shape to be seen in Figure 4, the screening plate 44 can also be bent simply. Located then in the region of the opening of the U is a narrow side 71 of the plastic housing 66, and arranged adjacent thereto is the previously mentioned second pair of switching contacts, which is connected to the screen and thus completes the socket screen instead of the missing sheet metal wall. In contrast, the signal-conducting pairs of switching contact tongues are located entirely in the screening region of the screening plate 44. The screening plate 44 lies like a thin coating on the plastic housing 66 and requires little space.

Figure 5 shows the appearance, known per se, of a functional plug 23 by means of thin and partly dashed lines. The plug-in part 78 projecting downwards is surrounded by a plastic mount 79 which extends around said plug-in part at a distance and, seen in the plug-in direction, has the shape of a rectangular ring. Arranged on its inner wall is a screening plate 46 which, for its part, leaves free a rectangular annular gap to the plugin part 78 with the contact tongues. The outline of the screening plate 46 is emphasized with thicker lines for clarity. In accordance with the sectional representation of Figure 6, it is bent approximately in the shape of a U, the bow 82 of the U being partially placed over the screens 39, which are exposed there, and preferably being soldered thereto. The two limbs 83 and 84 reach, extending essentially parallel to the contact tongues at a small distance over a large area, up to the front plug-in edge 85, and in this process cover the two inner flat sides 86 and 87 of the plastic mount 79. As Figure 5 shows, they do not extent away from the right-hand inner narrow side 88 entirely up to the opposite inner narrow side 89, specifically just as far as to cover laterally the second pair of contact tongues, which is situated nearest to the inner narrow side 89 and which is connected electrically to the screens 39. Here, too, the second pair of contact tongues undertakes the screening termination instead of the screening plate which is cut out there. This simplifies the bending operations for the screening plate 46, because projecting in each case from the limbs 83, 84 thereof towards the common centre plane 92 are angular parts 91 whose surfaces supplement one another to line the inner narrow side 88. Angular parts 93 also project from the limbs 83, 84 above the plug-in part 78 in the mounting region of the contact tongues, in order to complete a screening mount there.

The plastic mount 79 is formed by two housing shells 94 and 95, which can be connected in the centre plane 92 and also surround in an insulating fashion the entire screening plate 46 including the cable holder 96.

The housing shells 94, 95 have a plurality of inwardly projecting strips or lugs which centre and support the screening plate 46 and the plug-in part 78. In particular, two lugs 97 and 98 are provided which pass through slots 99 in the limbs 83, 84.

As Figure 6 shows, the screening plates 44 and 46 of the functional plug socket 18 and functional plug 23 likewise engage like a socket and plug, the lamellae 77 effecting resilient backlash compensation.

Claims

claims:

1. Connecting box for forming a connecting device for a data network, comprising a plastic housing, a circuit board, two BNC sockets and at least one functional plug socket having at least two switching contact tongues which are arranged in pairs on opposite inner sides of a plastic socket housing and touch one another in an electrically conductive fashion when no corresponding functional plug is plugged therebetween, the central contact sleeves of the BNC sockets being electrically connected directly via the mutually touching switching contact tongues of a first pair of switching contact tongues and corresponding conductor tracks of the circuit board, which conductor tracks are arranged on a first flat side of the circuit board, and it being the case that there is constructed on a second flat side, which is parallel thereto at a distance, a first conductor surface which covers the conductor tracks over a large area and is connected in an electrically conductive fashion to the screen terminals of the BNC sockets and to the switching contact tongues of a second pair of contact tongues, characterized in that there is a provided over the first flat side (48) of the circuit board (49) with the conductor tracks (43) an insulating layer (52) which has on a third flat side (53), which is at a distance from the first flat side (48) and parallel thereto, a second conductor surface (42), which covers the conductor tracks over a large area and is electrically connected to the first conductor surface (41), and in that there is applied to at least three outside surfaces (67, 68, 69), projecting essentially at right angles to the circuit board, of the plastic housing (66) of the functional plug socket (18) a screening plate (44) which is connected electrically to the conductor surfaces (41, 42).

2. Connecting box according to Claim 1, characterized in that the circuit board (47) is constructed as a multilayer board, the two outer layers forming the first and the second conductor surface (41, 42) and the centre layer forming the conductor tracks (43).

3. Connecting box according to Claim 1, characterized in that the screening plate (44) is bent approximately in the shape of a U over two mutually parallel flat sides (67, 68) and reaches a narrow side (69), aligned at a right angle thereto, of the plastic housing (66), and in that the screening plate (44) has a plurality of soldering lugs (76) which are integrally formed thereon and by means of which it is soldered to the conductor surfaces (41, 42).

4. Connecting box according to Claim 3, characterized in that the narrow side (69), enclosed by the screening plate (44), of the plastic housing (66) is directly adjacent to the first pair (21, 22) of switching contacts.

5. Connecting box according to Claim 1, characterized in that the screening plate (44) has a plurality of lamellae (77), integrally formed therein and projecting resiliently from the plastic housing (66), for contacting the inner wall of a screening sheath (46) of a functional plug (23).

6. Connecting box according to Claim 4, characterized in that the functional plug socket (18) has two adjacent pairs of switching contact tongues which in parallel produce the connection to the BNC sockets (16, 17) and are adjacent to the narrow side (69) enclosed by the screening plate (44), while a second pair of contact tongues, which makes contact with the screen terminals, is adjacent to the narrow side (31), cut out from the screening plate (44), of the plastic housing (66).

7. Connecting box according to Claim 1, characterized in that it has two functional plug sockets (18, 19), whose switching contact tongues (21, 22) are connected electrically in series, each functional plug socket being surrounded separately by a screening plate (44).

8. Connecting box according to Claim 1, characterized in that the plastic housing (60) is constructed in a bipartite fashion and encloses the circuit board (47) together with the functional plug socket (18) mounted thereon and surrounded by the screening plate (44).

9. Connecting cable for connecting a data processing device to a connecting box, in particular a connecting box according to one of the preceding claims, comprising a BNC plug at one end of the connecting cable and a functional plug at the other end which has at least two contact tongues arranged on opposite outer sides of a plug-in part, a signal line being connected in each case to the two contact tongues of a first pair of contact tongues, which signal lines are led, insulated from one another and screened, up to the BNC plug and are jointly connected to the central contact pin thereof, and the screens of the signal lines being electrically connected to the contact tongues of a second pair of contact tongues, characterized in that the plug-in part (78) of the functional plug (23) is surrounded by a plastic mount (79) whose inner wall leaves free an annular gap relative to the plug-in part (78) and encloses a screening plate (46) which, for its part, is at a distance from the plugin part (78), is arranged covering at least the first pair (25, 26) of contact tongues and is connected in an electrically conductive fashion to the screens (39) of the signal lines (27, 28).

10. Connecting cable according to Claim 9, characterized in that the screening plate (46) bears against two opposite inner flat sides (86, 87), and an inner narrow side (88), aligned at a right angle thereto, of the plastic mount (79), the inner narrow side (88) lined by the screening plate being adjacent to the first pair (25, 26) of contact tongues.

11. Connecting cable according to Claim 10, characterized in that the functional plug (23) has two adjacent pairs of contact tongues which are connected in each case in parallel to the signal lines (27, 28) and are adjacent to the inner narrow side (88) lined by the screening plate (46), while a further pair of contact tongues which makes contact with the screens (39) is adjacent to the inner narrow side (89), cut out from the screening plate, of the plastic mount (79).

12. Connecting cable according to Claim 10, characterized in that the screening plate (46) is bent approximately in the shape of a U, the bow (82) of the U extending at least partially over the exposed screens (39) of the signal lines (27, 28) and makes contact therewith, and the two limbs (83, 84) of the U respectively reach, essentially parallel to and at a distance from the contact tongues, up to the front plug-in edge (85), in the process covering the two inner flat sides (86, 87), and in that projecting in each case from the two limbs (83, 84) towards the common centre plane (22) are angular parts (91) whose surfaces supplement one another to line the inner narrow side (88) of the plastic mount (79).

13. Connecting cable according to Claim 12, characterized in that the plastic mount (79) is formed by two housing shells (94, 95) which can be connected in the centre plane (92) and also surround in an insulating fashion the entire screening plate (46) including the cable holder (96), the plastic mount (79) having a rectangular outer contour seen from the plug-in side.

14. A connector device for a communications network, comprising conductors (e.g. conductor tracks on a circuit board) enclosed by screening plates positioned close thereto.

15. A connecting cable for connecting to a connecting box according to one of claims 1 to 8 or a device according to claim 14.

16. A connecting box substantially as herein described with reference to the accompanying figures.

17. A cable for a connecting box, substantially as herein defined with reference to the accompanying figures.