EP0954888A1

EP0954888A1 - Housing for coaxial connectors

Info

Publication number: EP0954888A1
Application number: EP98901359A
Authority: EP
Inventors: Ville Nenonen; Kimmo NYYSSÖNEN; Timo Kettunen; Juha Virtanen
Original assignee: Nokia Telecommunications Oy
Current assignee: Nokia Oyj
Priority date: 1997-01-24
Filing date: 1998-01-23
Publication date: 1999-11-10
Also published as: FI102435B; FI970291A0; WO1998033237A1; FI970291A; FI102435B1; AU5767198A; CN1244301A

Abstract

A housing for SMB connectors (310) of a coaxial cable consists of a body (31), a handle part (32) and a spring (33). The body is provided with holes extending through it from the top surface to the bottom surface for receiving SMB connectors located at cable ends, and a T-profiled slip groove (35) extending beside the holes but having a transverse groove which extends at a distance from the body surface and partly through the holes. An edge of a transverse flange (52) in the handle part is wave-like so that in a first position of the handle part the wave chest is partly inside the hole keeping the SMB connector in its place, and in a second position the wave trough is located at the hole leaving the interior space of the hole vacant and allowing removal and replacing of the connector. The spring (33) in the housing keeps the handle part in the first position, from which it can be made to slide under an external force to a second position. When the effect of the external force ceases, the spring will make the handle part slide back to the first position.

Description

Housing for coaxial connectors

Field of the invention

This invention concerns a housing for connecting with their counter connectors the ends of several separate coaxial cables provided with standard coaxial connectors.

Background of the invention

The physical components of a telecommunications system are built by using special sub-racks, in which circuit cards, connectors, plug-in units, power supply units, fans and other such devices are located. Locating may be done already at the factory before the final installation site, whereby the furnished sub-rack will form a complete telecommunications module, which can be tested. The sub-rack is constructed in such a way that in each side of its front part there are flanges in parallel with the front part surface and the flanges are provided with holes. The sub-rack is of standard width without flanges, so owing to this standard width and dimensions devices made by different manufacturers can be placed in the same sub-rack.

For sub-racks, special racks are built where the sub-racks are at- tached. By way of simplified description the rack comprises two vertical mounting rails with holes and located at a standard distance from each other.

In practice, the rack is part of an equipment cabinet wherein several sub-racks can be located on top of each other.

In the equipment cabinet 1 shown in Figure 1 numbers 2, 3, 4 and 5 refer to different sub-racks mounted on mounting rails 7 and 8 located on the sides of the equipment cabinet. The sub-rack can be supported in the cabinet only at its side flanges or special shelves may be used, on which the sub-rack is placed. An especially heavy component, such as batteries 6, may be placed on the bottom of the cabinet. Plug-in units or BU (Board Units) are located in such a cabinet as shown in Figure 2. In the sub-rack constructed for plug-in units there is located in the back part a vertical back panel or circuit board 10, in which those electric circuits and internal circuit groups are formed through which card units are connected to that piece of telecommunications equipment to which the sub- rack belongs. In the back panel 10 there is at each card site a BPC (Back

Panel Connector), to which the cards are connected with their own back connectors BC. Through the back connectors BC and back panel connectors BPC the cards are connected e.g. to the internal multiplexer unit circuit group formed on the sub-rack's back panel. The front edge of the card unit may have a front panel, which is not shown in Figure 2 and at which the unit may be attached mechanically to the sub-rack and to which connectors may also be attached. The front panel also serves as an EMC (Electro Magnetic Compatibility) protector between the card and the environment.

Plug-in units are used e.g. in multiplexers, where a cable transferring a high-velocity e.g. 2 Mbit/s signal is brought to the card. In the card low-velocity 64 kbit/s channels are separated from the signal, they are processed along with channels of other cards in other units and 32 PCM channels are multiplexed into a 2 Mbit/s signal which is again forwarded from the card.

Incoming and outgoing coaxial cables can be connected in at least two ways to the plug-in unit. One way is to locate an FC (Front Connector) at the front edge of the card, such as an RF angle connector according to the standard, to which a socket-like RF connector according to the DIN 41626/2 standard at the end of the coaxial cable is connected. The latter connector is generally known under the name of SMB connector and the connection implements a 2 Mbit/s interface. Several angle connectors may be placed in parallel in a row at the card's front edge, as is shown in Figure 2, whereby one coaxial cable can be connected to each connector. There are even two-layer angle connectors, so two connector rows can be formed on top of each other. This of course makes it possible to increase the number of cables which can be connected to the card. Other connectors than coaxial connectors may also be used as front connectors, as is illustrated by reference numbers 21 and 22. These connectors can be used e.g. for connecting optical cables.

Another way of connecting coaxial cables to a plug-in unit is to make the back panel higher than the sub-rack and to locate RF connectors in the back panel part protruding from the sub-rack. Hereby coaxial cables are brought between two sub-racks to the back part of the sub-rack and SMB connectors at the cable ends are pushed into connectors in the back panel.

A third way is to leave in one side of the sub-rack a vacant space, in which no plug-in units are located. However, the back panel extends into this space and all necessary connectors are located at this place of the back panel. Another alternative is to locate a special connector panel in this space and mount the connectors on the panel. These known ways of connecting coaxial cables suffer from some drawbacks which become more obvious with a growing packing density of plug-in units. The performance of telecommunications equipment is growing constantly while the equipment is becoming physically smaller. Since more and more signals must be supplied to and taken from one plug-in unit, it has become an unavoidable problem how to place a great number of connectors in a small area and how to control the connectors.

When RF angle connectors according to the standard are used as front connectors at the front edge of the plug-in unit, such a situation will arise where the number of connectors is not sufficient, even though there are connectors over the whole width of the front edge and even in two separate layers. When there are tens of separate angle connectors, into each of which a cable terminated with an SMB connector is pushed separately, it will take much time to exchange a faulty plug-in unit, since each cable must first be removed separately and after the exchange of card unit it must again be connected separately to the angle connector. This is even more of a problem if the connectors are in the back panel, as each cable must then be drawn manually between sub-racks to the back panel and connected there to a connector in the back panel. It is a narrow space to work in. The same prob- lem must be faced when using a separate flush-mounted connector panel on the sub-rack side.

This invention aims at an arrangement where coaxial cables can be attached to and removed from counter connectors in the plug-in unit all at the same time as a group. In this way the plug-in unit could be exchanged without having to remove cables one at a time. The arrangement also aims at making it easy to remove and mount the individual cable, whereby it is easy to add and remove the individual interface.

The established objectives are achieved with the housing for coaxial connectors specified in the independent claims.

Brief summary of the invention

The connector housing consists of three parts: a body having a rectangular cross-section, a flange part extending in a groove and a spring.

For receiving coaxial connectors the body is provided with a set of parallel holes extending through the body from a first surface to a second opposite surface. In addition, the body is provided with a groove extending inside the body between the first surface and the second surface so that it extends partly through the interior space of each hole. The groove is preferably a T-profiled slip groove and its groove part opening into the body surface extends beside the holes but its transverse groove part extending at a distance from the body surface extends partly through the holes.

A movable flange part is fitted into the groove and the lateral surface of the flange facing towards the holes is wave-like in shape so that when the flange part is in its first position the wave chest projects into the interior space of each hole and when the flange part is in its second position the wave trough is at the location of each hole, thus leaving free the hole's interior space. The flange part is preferably a part of a T-profile or l-profile.

The housing also contains a spring, one end of which is attached to the body and the opposite end of which affects the flange part keeping it in the first position but allowing the flange part under the effect of an external force to move from the first position to a second position and again returning the flange part to the first position after the effect of the external force has ceased.

Brief description of the drawings

The invention will be described more closely referring to the at- tached diagrammatic figures, wherein

Figure 1 shows an equipment cabinet wherein sub-racks are mounted;

Figure 2 shows a plug-in unit;

Figure 3a is an exploded view of a connector housing according to the inven- tion;

Figure 3b shows the assembled connector housing;

Figure 4a is a perspective view of the body;

Figure 4b is a cross-sectional view of the body;

Figure 4c is an end view of the body; Figure 5a is a perspective view of the handle;

Figure 5b is a side view of the handle;

Figure 5c shows the handle seen from above; and

Figure 6 shows the spring.

Description of the preferred embodiment

Figure 3a shows the main parts of the connector housing: body 31 , handle part 32 and spring 33. When the handle part has been slipped into the body and the spring, which locks the handle to the body at the same time, has been attached in its position, the final result is as shown in Figure 3b.

The body structure will be described in the following referring to Figures 3a, 4a - 4c. The body is essentially of a rectangular cross-section and it is an elongated body made of insulating material. It may be made by injection moulding. Holes extend through the body, but only one of them is indicated by reference number 34 for the sake of clarity. The holes are symmetrically in two rows and the body shown in Figure 4a has 11 holes one after the other, whereby 22 cables may be connected to the connector. The number of successive holes may of course be bigger or smaller as required in each case. The holes can be seen most clearly in Figure 4a which shows the connector end face which is located against the connector's counter connector. The counter connector is described in detail in the applicant's Finnish Patent Application No. 970292 filed at the same time as the present application.

The hole diameter is so big that a standard coaxial connector socket SMB indicated by reference number 310 at the end of cable 39 in Figure 3a can be easily pushed into the holes from the direction of holding ears 37, 38, but it is nevertheless so small that the annular shoulder 312 at the back part of connector 310 can not enter the hole. This shoulder thus works as a stop, which prevents the connector from being pushed deeper. Figure 4b illustrates the position of connector 310 when pushed into a hole in body 31. The hole diameter is approximately equal to the diameter of annular flange 313 closest to the tip of the SMB connector socket. In the longitudinal direction of the body a T-groove 35 extends, the bottom 314 of which extends to a depth which is at the level of annular flange 311 of connector 310, Figures 4b and 4c. The straight part of the groove, which extends inwards from the body surface, extends between the rows of holes from one end of body 31 to its other end so that it is open at that end to which spring 33 is attached, but at the opposite end it terminates slightly before the end surface of the body. The transverse groove or T-part in the bottom of the straight part of the groove is of such a width that it extends partly through the internal part of the holes in each row of holes. This is illustrated in Figure 4c. The transverse groove also extends from one end of the body close to the other end.

It is essential in dimensioning the T-groove 35 that when the SMB connector socket has been pushed into the hole, so that annular shoulder 312 is against the body surface preventing any further pushing, the narrow part 311 of the connector socket is exactly at the T-part of groove 35. The height of the T-part is approximately equal to the length of the narrow part 311 of the connector socket.

In the end of body 31 where T-groove 35 begins a depression 36 is made for receiving one end 315 of spring 33.

If desired, flexible clamps 37 and 38 may be formed at the ends of the body to function as locking means when the connector housing according to the invention is placed e.g. into an opening made in the front panel of a plug-in unit, whereby the clamps will lock the body to the periphery of the opening.

Handle part 32 will be described next referring to Figures 5a, 5b and 5c. The handle part comprises a plate-like part 51 , the length L of which is approximately equal to the body length, or more precisely, length L is equal to the length of the T-groove made in the body. The thickness of the plate-like part is slightly less than the width of T-groove 35 in the body, so part 51 can slide easily in the groove. The edge of the plate-like part is provided with a flange part 52, having a width in the normal direction of the flange part and height in the direction of the flange part surface which are slightly less than the width and height of the transverse groove of T-groove 35 made in the body, so that flange part 52 has space to slide freely in the transverse groove.

The edges of flange part 52 have a wave-like shape so that they have successive wave troughs 53 and wave chests 54. The distance between wave chests is equal to the distance between successive holes in the row of holes in the body. The same goes for wave troughs. The edge thickness in the wave trough is equal to or less than the distance of a hole in the body from the hole located at a corresponding point in the adjacent row of holes, but the edge thickness at the wave chest is slightly bigger than the distance of a hole in the body from the hole at the corresponding point of an adjacent row of holes.

The outcome is that when the handle part is pushed into the T- groove in the body, even/ wave chest of the flange part edge in the first position will extend for some distance into the interior part of the hole located at the wave chest, while in the second position, which corresponds with a movement of the handle in the groove over the distance between wave chest and wave trough, the interior part of the hole is entirely vacant. As a result of this arrangement, when the SMB connector is pushed into a hole in the body, the handle when in the first position will lock the connector in the hole, because the wave chest of the flange part of the handle extends into groove 311 in the connector (Figure 4b), but in the second position the wave chest has become a wave trough, so the connector can be pulled out of the hole and also pushed into the hole.

Another flange part 55 can also be formed in the handle. This second flange part may be provided with holes 57, 58, 59 and 510, Figure 5c, through which cables are brought into holes in the body. The cables will thus remain as a coherent bundle close to the connector housing, so handling of the housing with its cables is easier.

In addition, a push-part 56 can be formed in the handle for pushing the handle with a finger in the body groove against the spring force. The above-mentioned spring force is formed with a spring as shown in Figure 6. The spring is S-shaped and it has a rod 316, the width W and thickness of which are equal to the width and thickness of the slot 36 made in the body, whereby the spring rod can be easily pushed into the slot. The arc 61 of the spring comes against flange part 51 of handle 32, and to prevent any lateral movement of the spring in relation to the flange part, arc 61 is provided with an opening 62 against the sides of which the flange part edge is supported. The other arc 63 of the spring is mounted away from the flange part of the handle.

It is obvious from Figures 3a and 3b how the connector housing is assembled of body, handle and spring. The handle is first pushed into groove 35 in the body so that flange part 52 enters the transverse groove at the bottom of groove 35. When the handle has been pushed all the way, spring 33 is placed at its rod 316 into slot 36 in the body, whereby the edge of the platelike part 51 in the handle will enter opening 62 in the arc of the spring. The connector housing is now complete. In this position the spring force will keep the handle pressed against one end of groove 35 in the body. This position was earlier called the first position, and in this position wave chests 54 on the edge of flange part 52 are located inside the holes in the body.

When cables 39 are located in the housing, the handle is pushed at its end face 56 against the spring force, whereby the handle will move over a short distance in the body groove and wave troughs in the flange part edge will be placed at the holes in the body. The flange edge, that is, the wave chests are thus not inside the holes, so the cable may be taken to the body through some opening 57, 58, 59 or 510 in the other flange part of the handle. SMB connector 310 at the cable end is pushed into the hole, until shoulder 312 of the connector is against the body surface. When the required number of cables have been pushed in this way into holes in the body, spring 33 is released and it will push the handle in the body groove 36 into a first position, where the wave chests in the flange edge enter the holes and there they enter the annular groove 311 of the SMB connectors. In this position, the wave chests will prevent the connectors from being pulled out of the body holes and they function as a stop when the connector is connected to its counter connector (not shown) in the front panel of the plug-in unit.

Individual cables can be easily removed from or new cables added to the presented housing for coaxial connectors. It is easy to remove the whole cable set at a go from the plug-in unit and correspondingly to connect it with the plug-in unit. A depression with counter connectors at its bottom and matching the dimensions of the connector may be formed in the front panel of the plug-in unit. Hereby clamps 37 and 38 in the side of the housing body will function as locking clamps. The structure of a suitable counter connector is described more closely in application FI-970292 filed at the same time as the present application.

The presented housing for connectors may be used in applications demanding many connectors in a small area and demanding flexible use, where all connectors can be removed at one go or where only an individual connector can be removed when required.

Keeping within the definitions of the claims, the housing may be embodied also in other ways than in the way presented above. For example, the groove in the body can be done so that it comprises only a transverse leg of a T-groove within the body. Hereby no groove opens into the body surface beside the holes. In this case the handle part would be reduced to just a flange part, that is, to a strip with wave chests and wave troughs at its sides. However, it is technically difficult to make such a groove. In such a case the spring would also be reduced e.g. to a strip spring, one end of which would press against a strip pushed into the groove and the other end of which would be pressed into a link made in the body.

Claims

1. Housing for coaxial connectors, characterized in that the housing comprises: a body (31), which has a set of parallel holes (34) extending through the body from a first surface to a second opposite surface for receiving coaxial connectors (310) and wherein a groove (35) is located which extends inside the body between the first surface and the second surface so that it extends partly by way of the interior space of each hole, a flange part (52) fitted to move in the groove and having a lateral surface facing towards the holes and shaped with a wave-like shape so that when the flange part is in its first position a wave chest (54) enters the interior space of each hole and when the strip is in its second position a wave trough

(53) is located at each hole, thus leaving the interior space of the hole vacant, a spring (33), one end (316) of which is attached to the body (31) and the opposite end (61) of which affects the flange part keeping it in the first position but allowing the flange part under the influence of an external force to move from the first position to the second position and returning the flange part again to the first position after the influence of the external force has ceased.

2. Housing as defined in claim 1 , characterized in that the holes are located in two parallel rows and that groove (35) extends between the rows.

3. Housing as defined in claim 2, c h a ra cte rize d in that groove (35) is profiled as a T-groove, where the transverse leg extends partly through the interior space of each hole and the longitudinal leg opens into the first surface between the rows of holes.

4. Housing as defined in claim 1 or3, characterized in that the groove at its one end opens into a side surface of the body.

5. Housing as defined in claim 3, characterized in that at least along a part of its length the flange part is a transverse part of a body as long as the groove and with a T-profiled cross-section, while the longitudinal part is fitted to move in the longitudinal leg of a T-groove located in the body.

6. Housing as defined in claim 3, characterized in that at least along a part of its length the flange part is a second flange of a body (32) as long as the groove and with an l-profiled cross-section while the opposite flange (55) is formed with openings (57, 58, 59, 510) through which coaxial connectors attached to ends of cables are led into holes in the body, while a plate-like part (51) connecting the flanges is fitted to move in the longitudinal leg of a T-groove in the body.

7. Housing as defined in claim 5 or 6, characterized in that the spring presses against the transverse part of the T-profiled body in the body or against the plate-like part (51) of the l-profile connecting the flanges.

8. Housing as defined in claim 1, characterized in that the diameter of holes is dimensioned so that when pushing a standard SMB coaxial connector into a hole an annular boss (312) in the back part of the connector will function as a stop which prevents the connector from being pushed deeper.

9. Housing as defined in claim 1 , characterized in that the distance of the groove extending partly through the interior space of holes from the connector surface is approximately equal to the distance of the annular groove (311) of the SMB coaxial connector from the annular boss (312) in the back part of the connector.

10. Housing as defined in claim 9, characterized in that the thickness of flange part (52) is approximately equal to the annular groove (311) of the standard SMB coaxial connector, whereby when the flange part is in its first position the wave chest is in the groove preventing the connector from moving in the longitudinal direction of the hole.