BI-VERTICAL MAIN DISTRIBUTING FRAME CONNECTOR

BI-VERTICAL MAIN DISTRIBUTING FRAME CONNECTOR

Technical Field

This invention relates generally to electrical terminal apparatus and, more particularly, to connector apparatus for use on a main distributing frame system in a telephone central office. Background of the Invention

The main distributing frame system in a telephone central office is the focal point of many work activities, and the system serves many diverse purposes, such as: interconnection juncture for joining central office equipment with outside plant facilities; access point for testing into or out of the central office; and protection provisioning interface. Thus, in a functional sense, the frame system provides for connection, testing, and protection.

Connectors used with, and secured to, main distributing frames are the electrical interface between feeder cables from the exchange area and the central office equipment. Connectors generally include a protector field and a cross-connect field, and are mounted on the vertical side on the main distributing frame. Stub cables that run from cable vaults below or above the main distributing frame, and consist of 100 incoming telephone line pairs, are connected to the protector field where protector units provide for each incoming line, voltage and current surge protection for the central office equipment. By indenting or detenting each protector unit, each unit also serves as a switch to individually connect or disconnect each telephone line to the cross-connect field. Jumper wires interconnect the cross-connect field, and either connecting blocks or terminal strips which, in turn, are connected to the central office switching equipment. Connectors may also include a separate test field for accessing the outside plant facilities for test purposes, or may, as will be noted hereinafter, have the accessing capabilities incorporated into the protector units.

The main distributing frame is the site of considerable craftsperson activity. In order to connect each telephone line in the stub cable to the central office equipment, the craftsperson individually connects a pair of jumper wires to a pair of terminals in the cross-connect field. The jumper wires are routed through distributing rings attached in the center of the frame. These operations require that the craftsperson be able to maneuver between connectors on adjoining verticals and perform routing therebetween. The physical characteristics of the craftsperson, such as his or her bicep dimensions and arm length, in conjunction with frame characteristics, such as interconector spacing and the distance from the front plane of the connector to the distributing ring region of the frame, determine the facility of the frame operations. In addition to being able to maneuver within the frame, the craftsperson must accurately connect the central office equipment to the outside plant facilities to prevent incorrect equipment interconnections. This requires unambiguous identification and association between the cross-connect terminals in the cross-connect field and the protector units in the protector field. Preferably, the cross-connect field and the protector field are front facing to facilitate accurate frame operations.

Prior art connectors are mounted to single vertical members of the main distributing frame. U. S. Patent No. 3,518,611 is representative of a typical prior art central office connector having separate forward-facing connector, protector, and test fields. In order to increase the density of connections per vertical member to improve the efficiency of central office equipment, high-density connectors were devised. Such connectors achieved high-density by rearranging the protector field, the cross-connect field, and the test field into a more compact structure. U.S. Patents No. 4,012,096, and No. 4,053,719 are representative of such prior art high-density connectors. Such connectors, however, created awkward frame operations and identification difficulties. In the '096 patent, the protectors and the cross-connect terminals are orthogonal to the front of the distributing frame. In the '719 patent, the protector field and the cross-connect field section are orthogonal to each other. In addition, the depth of these connectors is substantially deeper than the front-facing connectors, thereby increasing the distance to the distributing rings on the main frame and decreasing craftsperson accessibility. Another problem associated with prior art connectors is the inability to compartmentalize in the main frame bays, behind the connectors, the multi-wire stub and equipment cables from the jumper wires, since each bay is shared by both types of wiring. This increases the difficulty in adding new cabling.

An additional problem associated with prior art connectors is insufficient interconnector arm spacing. Human factors studies indicated that substantially improved frame operations would be achieved by increasing the interconnector spacing by less than 25 mm. Summary of the Invention

The foregoing shortcomings, limitations, and deficiencies in prior art connector devices are precluded with the present invention of an improved bi-vertical, high-density connector, which is mounted to two vertical members of a main distributing frame. The connector is totally front-facing and constructed such that the tops of the protector units within the protector field and the tips of the cross-connect terminals within the cross-connect field, all lie within one plane to eliminate errors due to paralax and to facilitate accurate identification by the craftsperson of protector units and their associated

OMH cross-connect terminals.

The connector in accordance with the present invention generally comprises a left and right unit, abutted in spatial mirror image, which together form the connector structure. Each unit comprises a protector field section and a cross-connect field section. The protector field includes a rectangular connector panel having front and back faces, a top and bottom, and opposed left and right sides, and a plurality of pin-grip connectors mounted through the connector panel for receiving pluggable electric protectors. The cross-connect field includes a rectangular cross-connect panel having front and back faces, a top and bottom, and opposed left and right sides, and a plurality of cross-connect terminals mounted through the cross-connect panel and extending forward of the front face and rearward of the back face. The protector and cross-connect fields are aligned so that one side of the cross-connect panel is disposed in the horizontal and vertical directions with the opposed side of the connector panel. A prismatic-shaped designation divider separates the protector field in the left unit from the protector field in the right unit. A similar divider in each unit also separates each cross-connect field and its associated protector field. These dividers focus the eyes of the craftsperson onto the unit he is working and provide surfaces for numerically identifying the terminals in the cross-connect field and the protector units in the protector field. A fanning strip, through which the jumper wires are routed, is disposed along protector field in each unit, and has a front edge surface for also providing numerical identification of the terminals in the cross- connect field. The front edge of the prismatic-shaped designation divider and the front edge surfaces of the fanning strips all lie within the same plane as the tips of cross-connect terminals and the tops of the protector units. The craftsperson thus has a completely planar and f ont-facing unit to minimize identification errors and maximize frame operability.

The connectors are mounted to two vertical members of the main distributing frame. This advantageously enables compartmentalization within the main frame of the multi-wire equipment and stub cables from the jumper wires. The bay directly behind the connector is allocated solely for the stub cabling and equipment cabling wires. In the adjoining bays, only the jumper wires from the left and right units of horizontally adjacent connectors are run. The addition of new cabling and jumper wire manipulations is thereby facilitated.

An additional advantage of the connector of the present invention is increased interconnector arm spacing for improved craftsperson maneuverability. Furthermore, the distance from the distributing ring to the front surface of the connector of the present invention is less than in prior art high-density connectors, thereby reducing the distance a craftsperson must reach into the frame to route jumper wires through the distributing rings. Brief Description of the Drawing

FIG. 1 is a pictorial view of the connector of the present invention showing the left and right units, each of which includes a protector field and a cross- connect field, the protector field in the left unit illustrated as having protector units inserted therein;

FIG. 2 shows a front view of the connector attached to two vertical members of a main distributing frame;

FIG. 3 is a rear view of the connector showing the stub cabling attached thereto;

FIG. 4 is an enlarged view of a portion of FIG. 3;

FIG. 5 is a side view of the connector; and

FIG. 6. is a top view of the connector. Detailed Description

As shown in FIG. 1, the connector 100 of this invention includes a left connector unit 101 and a right

O PI 1FO connector unit 102 abutted and indexed together in spati al mi rror image . As noted in FIG . 2 , the connector 100 is designed to be deployed across one bay of a main di stributing f rame by attachment to two verti ca l members 105 and 106, respective ly, of the di stri buting frame .

The lef t and ri ght connector units 101 and 102 are each capable of cross-connecting 100 pai rs of outsi de plant terminations. Each connecto r 100 is dimens ioned so that nine connector uni ts can be mounted in planar fashion on a 3 meter ve rtica l bay yi e lding a total cross-connect densi ty of 1800 pai rs per bay or , equiva lently, 900 interconnect ions per vert ica l member .

As will be described in detail hereinafter, connector units 101 and 102 each include a protector field and a corresponding cross-connect field. When inserted into the protector field, each protector unit interconnects the tip-and-ring wires of a pair within an attached stub cable to a pair of terminals in the cross-connect field. A pair of jumper wires attached to this pair of cross-connect terminals interconnect the switching equipment to the incoming tip-and-ring conductors. Each connector unit also includes a fanning strip for organizing and identifying the jumper wires and a designation divider which separates the protector field and the cross-connect field. Another designation divider separates the left and right connector units 101 and 102. As will be described, the fanning strip and the designation dividers are marked to numerically identify the terminals in the cross-connect field and the protector units in the protector field. In addition, these dividers are shaped to focus the attention of the craftsperson onto only the left or right connector unit. Furthermore, the fanning strip, the designation dividers, the cross-connect field, and the protector field are disposed within the connector unit in such a manner as to minimize craftsperson errors. Connector units 101 and 102 include mounting brackets 116 and 117, respectively. Brackets 116 and 117 are formed from stamped or machined steel sheets that are bent into essentially C-shaped brackets which have slots 118 (see FIG. 5) on the side portions thereof for attachment to vertical members 105 and 106 of the distributing frame. As noted in FIGS. 1 and 3, the top and bottom portions of brackets 116 and 117 are notched and grooved 119 for horizontal indexing of the left and right connector units 101 and 102. Brackets 116 and 117 each include pins 120-1 on the top portions thereof, and apertures 120-2 on the bottom portions thereof, for vertical indexing.

The discussion that follows hereinafter focuses only on left connector unit 101. It will be readily apparent to one skilled in the art that the discussion is equally applicable to right connector unit 102, the elements of which are in spatial mirror image to the elements in left connector unit 101. Minor differences between units 101 and 102 will be readily apparent to those skilled in the art.

The protector field of connector unit 101 includes a rectangular connector panel 106 having (see FIG. 6) front and back faces 145 and 146, respectively, a top 147 and a bottom 148, and opposed left and right sides 149 and 150, respectively. Connector panel 106 is formed of a suitable heat- and fire-resistant, durable, insulative material, such as a polycarbonate material commercially available under the trademark Lexan, owned by General Electric. Connector panel 106 is affixed within mounting bracket 116 between the top and bottom portions thereof and also includes a 5x10 array of groups of pin- grip connectors 107 adapted to receive plug-in electric protector units 108 therein (see FIG. 2) . Connector 100 has been designed to incorporate electric protector units 108 of the type disclosed in U.S. Patent No. 4,307,430. This patent describes a protector unit which incorporates test lands which are accessible through apertures 109 in the protector housing, and which, when inserted into the connector panel, provide electrical test access to the outside plant facilities. The need to provide a separate test field on the connector apparatus is thus obviated. Mounting bracket 116 includes notched cut¬ outs 143 and 144 (see FIGS. 1 and 3) on the top and bottom portions thereof, respectively, for the attachment of a testing tool of the type described in U.S. Patent No. 4,298,239. As described in that patent, such a testing tool comprises a matrix grid of spring-loaded pins mounted in a body in mirror image relation to the apertures in the protector units. As employed with the present invention, such a tool includes means for grasping mounting bracket 116 within cut-outs 143 and 144, and means for drawing the body portion of the tool towards the connector to drive the pins into the apertures 109 of the protector units 108. The testing tool is also used to grasp mounting bracket 116 such as to drive the pins into corresponding pin-grip connectors 107 on the connector panel 106.

Each group of pin-grip connectors 107 includes five active terminals arranged to match the mating pins of the protectors 108. With reference to FIGS. 3 and 4, the rear of connector 101 and a rear detail of one illustrative group 110 of such terminals 107 comprising terminals 111-1, 111-2, 111-3, 111-4, and 111-5 are shown, respectively. Terminals 111-1, 111-2, 111-3, 111-4, and 111-5, respectively, comprise the outside plant side of tip-and- ring, the switching equipment side of tip-and-ring, and ground. Terminals 111-1, 111-2, 111-3, and 111-4 have respective ends, or terminal portions 112, extending perpendicularly away from the back face 146 of connector panel 106 and have a flat cross-section so that wire attachment thereto can be mechanically effected. Ground terminal 111-5 has an end portion 113 connected to ground rod 114. As noted in FIG. 3, a ground rod 114 is vertically disposed behind each of the five

OMPI columns of terminals 107 in cross-connector panel 106, and two ground brackets 115 interconnect the five ground rods 114. The ground brackets 115 are connected to mounting bracket 116 which provides a connection to ground to vertical member 105 of the main distributing frame.

Associated with the protector field in connector unit 101 is a cross-connect field which includes a rectangular cross-connect panel 121 affixed within mounting bracket 116 in the spatial dimension perpendicular to the plane of the connector panel 106 in a parallel, but spaced apart, relation to connector panel 106. With reference to FIGS. 2 and 6, panel 121 has front and back faces 151 and 152, respectively, a top 153 and a bottom 154, and opposed left and right sides 155 and 156, respectively. It is also preferably formed of a polycarbonate material such as that sold under the trademark Lexan. The cross-connect field also includes, as can be noted in FIGS. 1, 2, and 6, a 4x50 matrix of cross-connect terminals 122 which are mounted perpendicularly to, and through, cross-connect panel 121, and which have front portions 124 which extend forward of the front face 151 and rear portions 123 which extend rearward of back face 152. Preferably, each terminal 122 has a rectangular cross-section to facilitate mechanical attachment of wires thereto. In the horizontal and vertical spatial dimensions, the right side 156 of cross-connect panel 121 is disposed along the left side 149 of connector panel 106. The terminals 122 are arranged so that every five rows of terminals 122 are vertically aligned with two rows of protector units 108. Each pair of terminals 122, consisting of a tip terminal and a ring terminal, is associated with one protector 108 in the adjacent protector rows. As will be described in detail hereinafter, the back portions 123 of each pair of terminals 122 are connected at the back face 146 of connector panel 106 to the associated switching side tip- and-ring terminals 111-3 and 111-4. Integral to cross-connect panel 121, and a physical part thereof, is a designation divider 125 which projects forward from the front face 151 of panel 121 and separates the cross-connect and protector fields (see FIGS. 1, 2, and 6) . The front portion of divider 125 is prismatic-shaped, having two rectangular surfaces 126 and 127 oriented rearwardly towards the front surfaces 151 and 145 of cross-connect panel 121 and connector panel 106, respectively. Surface 127 has numerical information printed thereon identifying the first protector unit 108 in the next adjacent protector unit row. Accordingly, every fifth numeral from 1 through 96 is printed thereon. Surface 126 has numerical information printed thereon identifying the second pair of terminals 122 in the next adjacent cross-connect terminal row. Accordingly, every even numeral from 2 through 100 is printed thereon. In addition, alternate five-row regions of cross-connect panel 121 are hot-stamped with a colored foil or, with alternate means, to assist in associating each five rows of terminals 122 with the associated horizontally adjacent two rows of protector units 108.

In prior art connectors, craftsperson identification errors are often the result of a paralax problem created by cross-connect terminals which are recessed relative to the tops of the associated protector units. In such prior art arrangements, the craftsperson will often be simultaneously functioning on, and focusing on, two different work planes which leads to errors. In accordance with the present invention, craftsperson identification problems are virtually eliminated. Firstly, connector panel 121 and terminals 122 therein are disposed in mounting bracket 116 so that, in three orthogonal spatial dimensions, the tips of the front portions 124 of terminals 122 and the tops of the protector units 108, when inserted into connector panel 106, are in the same plane. Accordingly, the craftsperson needs to function and focus on only one operational plane. Secondly, designation

O PI divider 125 is proportioned to extend forward of the front plane of cross-connect panel 121 so that the intersection of surfaces 126 and 127 lies in this same plane. The numerical identifications of the adjacent terminals 122 and protectors 108 are also essentially in the craftsperson's work plane. In addition, the angled designation divider 125 focuses the craftsperson*s eyes onto the particular area in which he is working and clearly separates the protector and connector fields. As will be described hereinafter, identification problems are further attenuated by means of numerical information printed on a fanning strip 128 and a designation divider 131, the latter separating the protector fields in the two connector units 101 and 102. With reference to FIGS. 1 and 6, a fanning strip 128, formed from a polycarbonate material such as that sold under the trademark Lexan, and having a forward portion 135, a rear portion 136, and a front edge surface 134 is attached to mounting bracket 116 to the left of, and adjacent to, left side 153 of cross-connect panel 121. Fifty slots 129 are vertically disposed through front edge 134 of the forward portion 135 of fanning strip 128 so that each slot is adjacent to a row of four terminals 122 in cross-connect panel 121. Ten slots 130 are vertically disposed along the rear portion 136 of fanning strip 128. Fanning strip 128 is disposed in mounting bracket 128 so that front edge surface 134 is in essentially the same plane as the tips of terminals 122 and the tops of protectors 108. Printed onto surface 134 is the numerical identification of the first pair of terminals 122 in each next adjacent row. Accordingly, every odd numeral 1 through 99 is printed thereon.

Incorporated within connector unit 101, and attached between the top and bottom portions of mounting bracket 116, is designation divider 131, which is formed from a polycarbonate material such as that sold under the trademark Lexan. When left connector unit 101 is horizontally indexed with right connector unit 102 on adjacent vertical frame members 105, and 106, divider 131 separates and numerically identifies the adjacent protector units 108 in the protector fields of both connector units. Furthermore, the angled divider maintains the focus of the craftsperson on only the unit he or she is working. Designation divider 131 has a prismatic-shaped front portion having two rectangular surfaces 132 and 133, which are oriented rearwardly towards the connector panels 106 in connector units 101 and 102, respectively. Printed on surface 132 are the numerical identities of the last protector units 108 in each adjacent row in connector panel 106 in connector unit 101. Similarly, printed on surface 133 are the numerical identities of the first protector units 108 in each adjacent row in connector unit 102. Designation divider 131 is disposed within mounting bracket 116 so that the intersection of surfaces 132 and 133 lies in the same plane as the tips of the front portion 124 of cross-connect terminals 122, the tops of protector units 108, the front edge of designation divider 125, and the front edge surface 134 of fanning strip 128. It is readily apparent that designation divider 131 serves both connector units 101 and 102 and does not have a corresponding component in connector unit 102.

Connector unit 101 also includes a plastic protective strip 140 (see FIGS . 1 and 6) disposed between the left edge o f connector panel 106 and the right edge of designation di vider 125 to i solate and protect the back plane wiring from the front plane craftsperson operational activities.

A 100-pair s tub cable 141 is connected to the back plane of connector pane l 106 (see FIG . 3) . The tip- and-ring conductors of each pair of wires 142 within stub cable 141 are indi vidually wi re-wrapped to the terminal portions 112 of the outside plant tip-and-ring terminals 111-1 and 111-2 (see FIG . 4) . In order to

O H simplify the drawings, connection of the tip-and-ring conductors 142 to terminals 111-1 and 111-2 is not shown. A second set of wires (not shown) is wire-wrapped to the terminal portions 112 of the switching equipment tip-and- ring terminals 111-3 and 111-4. The other ends of these wires are wire-wrapped to the end portions 123 of the terminals 122 in the cross-connect field 121 that numerically correspond to the particular group of pin-grip connectors to which the wires are connected. When a protector 108 is inserted into the pin-grip connectors 107 in the connector panel 106, a direct electrical connection is made between a pair of conductors 142 in the stub cable 141 and a pair of terminals 122 in cross-connect panel 121. To connect the switching equipment in the central office to the connector, a pair of jumper wires is wire- wrapped to the front portions 124 of a pair of cross- connect terminals 122. The two jumper wires, connected to a pair of terminals 122 in each row of cross-connect terminals, are snapped into an aperture 129 in the front portion of fanning strip 128. Five adjacent groups of these two wires are further grouped and snapped into an aperture 130 in the rear portion of fanning strip 128. This grouping of jumper wires facilitates the orderly routing of the jumper wires behind the bay. The jumper wires are routed through distributing rings at the rear of the main frame, and then connected to connecting blocks or terminal strips which interconnect the switching equipment. It is apparent from FIGS. 2, 3, and 6, that the bay between the vertical frame members 105 and 106, which support connector units 101 and 102, contains only stub cabling, and the two adjacent bays contain only jumper wires. Such bay compartmentalization facilitates the running of additional stub cabling within the central office, and also facilitates running of the jumper wires through the distributing rings on the main frame as additional connectors are added to the main frame.

v Although the connector 100 of the present invention has been described as including two connector units 101 and 102, the connector could also be interconnected and manufactured as a unitary structure.