MAIN DISTRIBUTION FRAME STRUCTURE

Abstract: A main distribution frame (10) which includes first and second connector devices (66, 68) for effecting first cable terminations to internal plant and second cable terminations to external plant, respectively, the connector devices (66, 68) each having a plurality of cable terminals (80), an upright support structure (12, 14, 18, 20), mounting units (30) for supporting from the structure (12, 14, 18, 20) at least one end-to-end extending layer (110) of the connector devices (66, 68), the first connector devices (66) being positioned along the length of the layer (110) adjacent the second connector devices (68) and being differently orientated with respect to the second connector devices (68). A mounting unit (30), which includes mounting elements (34, 40) arranged substantially perpendicular with respect to each other for the two types of connector devices (66, 68), is also provided.

Description: MAIN DISTRIBUTION FRAME STRUCTURE This invention relates to a main distribution frame structure. In telephone exchanges it is customary to provide a main distribution frame, by which is meant a structure upon which is mounted connector devices of two kinds, one kind being connected to what is usually called "external plant" meaning cabling, for example in the street, and intended to go to exchange customers' equipment such as telephones and to junction cables between exchanges, the second kind connecting to what is termed "internal equipment" or "internal plant" by which is meant cabling to active devices within the telephone exchange, particularly switching equipment. The cabling associated with the two kinds of connector device is terminated at those connector devices and conductors, called "jumper leads" are then interconnected between connectors of the two kinds as required in order to provide desired coupling between the customers' cabling and the cabling to the active devices in the exchange. As new customers are added to the exchange, further switching equipment or the like is required in the exchange and the number of cables to the connectors of both kinds increases, as does the number of jumper leads. Furthermore, from time to time it may be necessary to alter connections between selected ones of the connector devices, which involves replacement of the jumper leads. In any event, the end result is that in an exchange which has been operating for some time and which is servicing numerous customers, the number of jumper leads may increase to such an extent that adding new connections by adding new jumper leads or altering existing interconnections becomes extremely difficult. Large exchanges may service tens of thousands of customers and particularly if there is no pre-ordered arrangement of the connector devices, the density of jumper leads may be very high indeed, thus seriously interfering with accessibility. By adopting arrangements where order is maintained in that regard, the problem can be lessened, although not completely overcome. By positioning the devices of the two kinds such as to ensure that jumper lead length is minimised, the system is said to have preferred assignment. A system where all jumper connections run between preferred points is termed "100 percent preferential assignment" and such an arrangement is generally more efficient, but requires a greater degree of management. It is however not necessary nor practically desirable to employ 100% preferential assignment for technical reasons, but it is desirable if possible to employ arrangements utilizing rather high preferential assignment values, in the interests of containing the problems caused by presence of large numbers of jumper leads. Most of main distribution frame research has been targetted towards structures which are, operationally, similar to a honeycomb in the sense that they may be considered to comprise a large storage system made up of a number of individual storage cells arranged in an array. Generally, a conventional main distribution frame may be compared to one very large storage tank in which there is no restriction on the possible jumper connections. On the other hand, in an ideal main distribution frame, the jumpering is contained within an individual cell (or neighbourhood at least) of the main distribution frame. In particular, while it may not be possible to fully achieve an arrangement in which there is no jumpering in between cells, it is at least, in the ideal case, desired to achieve an arrangement where, in the event that such jumpering does exist, it is heavily restricted in the sense that interconnections between cells are, insofar as possible, between closely adjacent cells with relatively few long jumpers between relatively distant cells. A particular defect with prior art arrangements lies in that it is difficult to provide in certain of them, the preferred assignment in this fashion and furthermore, in that some forms have unsatisfactory provision for supporting long jumpers where these are necessary. Whatever system is employed, there is ultimately a practical limit to how many connector devices can be positioned on a single main distribution frame, in terms of the possible number of jumper leads which can in any event be physically packed into spaces within the frame. For example, in Australian practice it has been customary to position connector devices of one of the aforementioned kinds in a vertical array at one side of the frame and the devices of the other kind in a vertical array at the other side thereof so that, essentially, the jumper leads are provided to interconnect between opposite sides of the frame. Other countries have similar main distribution frame practices. Obviously, there is a limit to the.. number of leads which can be so accommodated in the space between the two sides. Other problems arise from cable congestion above the main distribution frame or at the entry vault or cable tunnel in which the incoming cables enter the exchange. In some cases, notwithstanding that the cable entry tunnel is of much greater physical capacity than is needed to accommodate the number of cables therein, constraints due to the manner in which the cables are to be terminated at the main distribution frame bring the result that the congestion between the main distribution frame and the vault becomes so great that less than the whole capacity of the vault is usable. Similar problems can arise where termination to the main distribution frame occurs from locations above the frame. Another difficulty with conventional main distribution frames lies in the lack of flexibility of design of the support structure of the frame, which places constraints on the layout and expandability of the main distribution frame. This results in a reduction in maximum usable capacity, and inefficient operating practices. One object of the invention is to provide a main distribution frame which at least substantially lessens one or more of the problems above described. Another object is to provide a mounting structure for connector devices of a main distribution frame and which can be arranged or rearranged to provide good accessibility between connector devices of the above mentioned two kinds and which can readily be adapted to provide a main distribution frame of desired size, capacity or configuration. Another object is to provide a mounting unit incorporatable into such a structure. In one aspect, the invention provides a main distribution frame for terminating cables going to internal plant at first cable terminations, for terminating cables going to external plant at second cable terminations, and permitting interconnection between said first and second terminations by use of jumper leads, the main distribution frame comprising: first and second connector devices for effecting said first and second terminations, respectively, said connector devices each having a plurality of cable terminals; an upright support structure; and means for supporting from said structure at least one end-to-end extending layer of said connector devices; said first connector devices being positioned along the length of the layer adjacent said second connector devices and being differently orientated with respect to said second connector devices. In a particular form of the invention said first connector devices are orientated substantially perpendicular with respect to said second connector devices. Preferably, the means for supporting the connector devices provides an end-to-end extending cable support platform for supporting said cable. Thus, the means for supporting may be in the form of a plurality of mounting units arranged end-to-end along the length of said layer and each supporting therefrom a plurality of connector devices and each providing at least part of said support platform. The main distribution frame may include a plurality of layers each formed as above described, the layers being vertically spaced whereby each said platform can support jumper leads. In addition to the aforedescribed layer, the main distribution frame may include one or more further layers including connector devices providing for termination of jumpers to one of said external and internal plant only and providing a further support platform means for running of jumpers therealong. In another aspect, the invention provides a main distribution frame as claimed in claim 5, further comprising at least one further layer including a further support platform for supporting jumper leads, and either said first connector devices or said second connector devices only. The mounting elements may, for example, be of elongate form and be provided with apertures or other structure permitting mounting thereto of a number of connector devices in the form of electrically insulative bodies carrying thereon electrically conductive terminals. The connector devices may each be of elongate form with rows of said terminals extending end-to-end along the length of the respective insulating body and positioned at one generally planar face of the body, the rows each comprising a plurality of said terminals and the rows extending transversely across said face. In such case, it is preferred that the mounting elements be arranged so that at least two of said connector devices may be mounted to the unit, each extending lengthwise along and being interconnected with a respective one of the mounting elements. Generally, it is preferred that there are at least three said mounting elements, two of which are arranged in parallel spaced relationship and the third of which is arranged at right angles to the other two, such as having the other two extending in parallel relationship from the third mounting element at spaced locations from the length thereof or from locations which are spaced from but adjacent to spaced locations along the length thereof. In one form of the invention there are five said mounting elements, one including three end-to-end located said portions thereof, and the other four being parallel to each other, being substantially normal to said one mounting element defining said portions thereof. The invention also provides a main distribution frame support structure including a plurality of parallel support members arranged substantially in said first plane and at least one unit as above described fixed thereto so as to mount the mounting elements in the aforementioned second plane. The invention also provides a main distribution frame comprising a main distribution frame structure as last described and fitted with a plurality of electrical connector devices for terminating cables thereat. The invention is further described by way of example only with reference to the accompanying drawings in which: Figure 1 is a perspective view of part of a main distribution frame structure constructed in accordance with the invention; Figure 2 is a perspective view of a mounting unit incorporated into the main distribution frame structure of Figure 1; Figure 3 is a perspective view of another form of mounting unit incorporated into the main distribution frame structure of Figure 1; Figure 4 is an enlarged fragmentary view illustrating the positioning of mounting members of a mounting unit and upright supports of the main distribution frame structure of Figure 1; Figure 5 is an enlarged cross sectional view illustrating the manner of interconnection between upright support members and mounting units forming part of the main distribution frame structure of Figure 1; Figure 6 is a perspective view illustrating the interconnection of connector devices fixable to the main distribution frame structure of Figure 1 to form a main distribution frame; Figures 7 and 8 are transverse sections of a mounting element, forming part of the mounting unit of Figure 2, illustrating the manner of attachment of a connector device thereto; Figure 9 is a perspective view of a main distribution frame constructed in accordance with the invention and illustrating allocation of connector devices as between external and internal plant; and Figure 10 is a diagrammatic end view of a main distribution frame constructed in accordance with the invention. Referring firstly to Figure 1, the main distribution frame structure 10 shown therein includes first and second sets 12, 14 of upright support members 16. The support members 16 in set 12 are parallel to each other and arranged in a single vertical plane. Those in set 14 are likewise parallel and arranged in a single vertical plane parallel to the plane containing support members of set 12. The two planes are spaced apart, a distance of, for example, 300mm. As shown, the support members 16 in set 12 are secured to and extend upwardly from a lengthwise extending horizontal base member 18 and those in set 14 similarly extend from and are fixed to a horizontal base member 18 parallel to the first mentioned base member. Support members 16 in each of the sets are interconnected in various ways to form a rigid upright structure, such as by interconnection of upper ends thereof by transverse members 20 and interconnection between members 16 in the two planes containing the sets 12, 14 by use of lengthwise extending trays 22. The structure 10 may be secured together by bolting together of the component parts. Also included in the structure 10 are a number of mounting units 30 of the kind shown in Figure 2. The unit 30 comprises two somewhat box-shaped and cage-like components 32. Each unit 30 comprises two parallel, spaced, upright mounting elements 34 from which extend, in a rearward direction, lower spaced parallel members 35 and upper spaced parallel members 37. These members 35, 37 join at the ends remote from the mounting elements to a generally planar wall 38. The two components 32 are arranged side by side as shown, with the elements 34 of both components in a common vertical plane so that the walls 38 are likewise in a single plane parallel to and spaced from that containing elements 34. The two elements 34 are joined by a transverse third mounting element 40 which extends normally to the two elements 34 of each component 32 and joins the two components 32. Thus, the element 40 of each component 32 joins the members 37 at the junction between elements 34 and members 37, so that the elements 34 extend downwards from the element 40 at spaced locations along the length of the element 40. The elements 34 and 40 have openings 46, 36 therein at spaced locations along the lengths thereof, whilst the walls 38 have openings 48 therein. Units 30 are bolted to the support members 16 in the fashion shown in Figure 5. In particular, the members 16 have forwardly open lengthwise extending slots 16a and bolts 54 are provided which extend through the openings 50 in the wall 38 and into threaded elements 56 retained within the support member 16, behind the slots 16a. When so positioned, the elements 40 and 34 of the units 30 associated with each set 12, 14, of support members 16 are positioned with the elements 40 extending horizontally and the elements 34 vertically, downwardly from elements 40, and in a coplanar array, the plane of which is parallel to and spaced somethat in front of the plane of the respective set of support members 16. Aside from the units 30, the structure 10 includes at its lower portion a number of somewhat differently formed mounting units 60 of the kind shown more particularly in Figure 3. Each of these has a lengthwise extending mounting element 40 only and does not possess the mounting elements 34. Two generally U-shaped mounting components 62 are provided at the rear of the element.40 and these are secured to ones of the support members 16 in each set 12, 14 by means of bolts (not shown), so that the element 40 is contained in the same plane as the elements 40 and 34 of the units 30 associated with that set 12, 14. As shown in Figure 6, each mounting unit 30 is capable of accepting thereon seven connector devices 66, 68, there being four of the devices 68 and three of the devices 66. More particularly, each mounting element 40 defines three end-to-end portions 40a, 40b, 40c, upon which the three devices 66 are mounted each by means of a plurality of hook elements (bolting pins) positionable in ones of the slot-like openings 36. The hook elements may, for example, comprise rearwardly protecting pins with enlarged heads, the openings 36 having an enlarged upper portion 36a into which the head may be received and a downwardly depending slot-like portion 36b of lesser width than the head of each element whereby the heads may be entered into the slots at the portions 36a and the hook elements then moved downwardly by movement of the device 66 upon which they are retained so that narrow neck portions of the hook elements are retained in the portion 36b. To facilitate this action, the element 40 is, as shown, in the form of angle cross-section having two lengthwise extending sections 40d, 40e, arranged at right angles and a smaller corner section 40f which extends at 30" to the section 40e, and 60» to the section 40d. Portions 36a of the openings 36 are positioned adjacent the junction line of sections 40d, 40f, with portions 36b extending across sections 40e, 40f. Figures 7 and 8 illustrate the action involved in attaching a device 66 to an element 40. Here, one hook element is designated by reference numeral 70, and has a small diameter portion 70a projecting from the rear of the device 66 and an enlarged head 70b. As shown in Figure 7, the device 66 is first tilted upwardly at an angle of about 30 β to the horizontal as viewed from the side and is then moved towards the element 40 so that the head portion 70 is passed through the portion 36a of slot 36 to locate the head portion 70b behind the section 40f of the element 40. The direction of movement to effect this is indicated by arrow 72 in Figure 7. Then, the device 66 is swung downwardly in the direction indicated by arrow 74, as shown in Figure 8, to enter the element 70 into the slot portion 36b, more particularly to enter thereinto the portion 70a thereof, with the head portion 70b being behind the slot and engaging rear surface portions of the section 40e of the member 40 disposed one to either side of the portion 36b of the slot 36. The ability to swing the device 66 as before described permits the device to be temporarily positioned at a location similar to that shown in Figure 7, such as by holding of head portions 70b against an upper rear surface portion of the section 40f immediately above the opening portion 36a to facilitate access to the devices particularly when required for making connections thereto. The devices 68 are of generally similar form to the devices 66 and are secured to the elements 34 in similar fashion, but require to be swung about vertical axes to effect engagement with the elements 34, in view of the latter extending vertically. In this regard, elements 34 are each of angle section form having two lengthwise extending sections 34a, 34b and a connecting corner section 34c arranged at 30° to these, in similar fashion to the elements 40. Again, the openings 46 are of slot-like form having enlarged head portions 46a positioned on the junction line between sections 34b, 34c and slot-like portions 46b extending therefrom, across the section 34c and onto the section 34a. The openings 36 in the section 40 associated with unit 60 are also similarily configured to those on the section 40 associated with unit 30, and mounting of devices 66 thereon is effected in the same way as described in relation to units 30. The connector devices 66, 68 are of generally like form, each having an insulating body 78 with a number of electrically conductive contact terminals 80 thereon, these being arranged in a number of rows which are side by side and which extend transversely across a front face of each. The devices 66 are slightly smaller than the devices 68, having fewer terminals. Further, because there are four devices 68 and only three devices 66 associated with each unit 30 there are for each unit 30 fewer terminals associated with devices 66 than are associated with devices 68. By assigning the devices 66 for use with cabling to active devices within the telephone exchange and using the devices 68 for cabling to the street going to customers or the like, effective use is made of the available space on the frame structure 10, since the number of terminals required for connection to active devices within the exchange is usually less than the number required for external plant. In use, the main distribution frame formed by use of the support structure 10 and devices 66, 68 as above described may be used in the same way as conventional main distribution frame, with connections being established to the terminals of the connector devices as required by use of external cabling and by use of jumper leads therebetween. Because devices 66, 68 providing connection to both external and internal plant are located adjacent each other and generally in a single plane forwardly of the associated respective set of support members 16, the length of jumper leads may be minimised. Furthermore, extension of the capacity of the main distribution frame may readily be increased by adding more mounting units 30 as required. Where, the lesser number of devices 66 as compared with devices 68 causes a deficiency in the required number of devices 66, use may be made of the aforedescribed units 60, to provide mounting for further devices 66. As shown, the structure 10 is designed to permit units 30 to be secured to each of two sides, one to each of the sets 12, 14 of support members 16. Alternatively, it would be possible of course to provide a single-sided unit having only one of the sets 12 or 14. Figures 9 & 10 illustrate one manner of allocation of devices 66, 68 as between external cable and internal equipment, such as the line interface equipment. Furthermore, various jumpers 96 are shown, by way of example, and these run between various of the devices. This running is facilitated by the use of jumper guides 94. It will be observed that units 30 are arranged in end-to-end extending sets so as to form vertically spaced layers 110 of devices 66, 68 there being, within each layer, a number of devices 66 and a number of devices 68 each device 66 being adjacent at least one device 68. At the top of each layer, the members 37 of the units 30 form a support platform 100 for running of the jumpers 96. Furthermore, since the layers 110 are spaced apart from each other vertically, there is a space 98 (Figure 10) between each layer within which the jumpers are readily laid on the platform 100 so defined. Also as shown in Figure 10, where the units 60 are employed, these likewise form an end-to-end extending layer 110, in this case having only devices 66, the mounting components 62 again defining an upper platform for supporting jumpers. The described arrangement has been advanced merely by way of explanation and many modifications and variations may be made thereto without departing from the spirit and scope of the invention which includes every novel feature and combination of novel features herein disclosed.

Claims: CLAIMS 1. A main distribution frame (10) for terminating cables going to internal plant at first cable terminations, for terminating cables going to external plant at second cable terminations, and permitting interconnection between said first and second terminations by use of jumper leads (96), the main distribution frame (10) comprising: first and second connector devices (66, 68) for effecting said first and second terminations, respectively, said connector devices (66, 68) each having a plurality of cable terminals (80); an upright support structure (12, 14, 18, 20); and means (30) for supporting from said structure (12, 14, 18, 20) at least one end-to-end extending layer (110) of said connector devices (66, 68); said first connector devices (66) being positioned along the length of the layer (110) adjacent said second connector devices (68) and being differently orientated with respect to said second connector devices (68). 2. A main distribution frame (10) as claimed in claim 1, wherein said first connector devices (66) are orientated substantially perpendicular with respect to said second connector devices (68). 3. A main distribution frame (10) as claimed in claim 1 or 2, wherein the supporting means (30) provides an end-to-end extending support platform (100) for supporting cables. 4. A main distribution frame (10) as claimed in claim 3 , wherein said supporting means (30) includes a plurality of mounting units (30) arranged end-to-end along the length of said layer (110) and supporting therefrom a plurality of said connector devices (66, 68) and each providing at least part of said support platform (100) . 5. A main distribution frame (10) as claimed in claim 3 or 4 , further comprising a plurality of said layers (110) spaced vertically with respect to one another whereby each said support platform (100) can support jumper leads (96) . 6. A main distribution frame (10) as claimed in claim 5, further comprising at least one further layer (110) including a further support platform (100) for supporting jumper leads (96) , and either said first connector devices (66) or said second connector devices (68) only. 7. A mounting unit (30) for mounting to generally upright parallel support members (16) arranged substantially in a first plane, and comprising first and second mounting components (32) fixable to respective ones of said support members (16) whereby portions of mounting elements (34 , 40) of the mounting unit (30) , arranged to be at an angle with respect to one another and disposed in a second plane, are then positioned so that said second plane is substantially parallel to said first plane. 8. A mounting unit (30) as claimed in claim 7, wherein said mounting elements (34, 40) are of elongate form and are provided with means (36, 46) permitting mounting thereto of a number of connector devices (66, 68) in the form of electrically insulative bodies (78) which include electrically conductive terminals (80). 9. A mounting unit (30) as claimed in claim 8, wherein said connector devices (66, 68) are each of elongate form with rows of said terminals (80) extending end-to-end along the length of the respective insulative body (78) and positioned at one generally planar face of the body (78), the rows each comprising a plurality of said terminals (80) and extending transversely across said face. 10. A mounting unit (30) as claimed in claim 9, wherein said mounting elements (34, 40) are arranged so that at least two of said connector devices (66, 68) can be mounted to said unit (30), each extending lengthwise along and being interconnected with a respective one of said elements (34, 40). 11. A mounting unit (30) as claimed in claim 10, wherein said unit (30) includes at least three of said mounting elements (34, 40), two (34) of which are arranged in a parallel spaced relationship and the third (40) of which is arranged substantially perpendicular to the other two (34). 12. A mounting unit (30) as claimed in claim 11, wherein the two parallel elements (34) extend from the third element (40) at spaced locations along the length thereof. 13. A mounting unit (30) as claimed in claim 11, wherein the two parallel elements (34) extend from locations which are spaced from but adjacent to spaced locations along the length of the third element (40). 14. A mounting unit (30) as claimed in claim 10, wherein said unit (30) includes at least five of said mounting elements (34, 40), one (40) including three end-to-end located portions thereof, the other four (34) being substantially parallel with respect to each other, being substantially perpendicular to said one (40) mounting element and defining said portions of said one element (40). 15. A mounting unit (30) as claimed in any one of claims 8 to 14, wherein said connector devices (66, 68) include first connector devices (66) for providing cable terminations for internal plant and second connector devices (68) for providing cable terminations for external plant, said connector devices (66, 68), in use, being mounted on said mounting elements (34, 40) such that said first connector devices (66) are orientated differently with respect to said second connector devices (68), in accordance with the orientation of said portions of said mounting elements (34, 40). 16. A mounting unit as claimed in claim 15, wherein the planar faces of the insulative bodies (78) of adjacent said first and second connector devices (66, 68) when mounted face the same direction and are relatively accessable for the connection of said jumper leads (96) thereto. 17. A mounting unit (30) as claimed in any one of claims 8 to 16, wherein said permitting means (36, 46) of said elements (34, 40) and cooperating mounting means (70) of the connector devices (66, 68) are configured to enable said connector devices (66, 68) to be held in a temporary position by said mounting elements (34, 40), wherein connection of jumper leads (96) and cables thereto is facilitated. 18. A mounting unit (30) as claimed in claim 17, wherein said permitting means (36, 46) are apertures and said cooperating mounting means (70) are hook elements. 19. A main distribution frame support structure (12, 14, 18, 20) including at least one mounting unit (30) as claimed in any one of claims 8 to 18 and said generally upright parallel support members (16) arranged substantially in said first plane, said at least one unit (30) being fixed thereto so as to mount the mounting elements (34, 40) in said second plane. 20. A main distribution frame comprising the support structure (12, 14, 18, 20) as claimed in claim 19 and said connector devices (66, 68) mounted thereto.

Inventors: DUNCAN KENNETH DAVID, LEWIN JOHN NORMAN, LONGLAND DAVID GEORGE, RADKE KEITH FREDERICK, DUNCAN, KENNETH, DAVID, LEWIN, JOHN, NORMAN, LONGLAND, DAVID, GEORGE, RADKE, KEITH, FREDERICK
Applicants: AUSTRALIAN TELECOMM, AUSTRALIAN TELECOMMUNICATIONS CORPORATION
Application year: 1989
Main classification: H04Q1
IPC codes: H04Q1