[1]United States Patent Office 3@456@231 3,456,231 INTTERCONNECTION WIRING SYSTEIM Clarence Leonard Paullus, Camp HIII, and John Aaron Zim.merman, Jr., Hershey, Pa., assignors to AMP Incorporated, Harrisburg, Pa. Filed May 23, 1967, Ser. No. 640,649 lnt. Cl. HOlr 11102, 13160, 9100 U.S. Cl. 339-60 17 Claims ABSTRACT OF THE DISCLOSURE Modular interconnection wiring system comprises a plurality of modules each having grotips of contact receiving sockets therein. Each group of sockets comprises one or more pairs of individual sockets so that varyin@ numbers of contact pins can be commonly connect@d. Modules and sockets can be assembled to each other in two different modes to achieve either interconnections among wires extending axially towards each other or interconnections amon.- parallel wires extending to a function area. In accordance with one embodiment, modules are mounted en bloc between spac,-d-apart rails having means for retaining the modules between the rails but permitting removal of an individual module from the middle of a module stack. BACKGROUND OF THE 1NVENTION A wide variety of interconnection wiring systems or terminal junc+ion systems, as they are commonly called, are known to the art, however, most of these systems are relat-1vely bulkly and are not enviroamentally sealed. Previotisly known systems have, for the most part, been used on stationary eqtiipment of the type in which there are a few limitations on available space or -,vhere there are wei,@ht limitations imposed on the designer. More recently, a need has arisen for an interconnection system which can be used under the exacting conditions of aircraft manufacture and siinilar circumstances. A further requirement is that the modular interconnection system be capable of commoning wires extending to a common j'unction area on oii.- side of a bulkhead or wall and/or commonin-. N@iires in a junction area in a bulkhead, that is, formin- common connections amon- wires extending towards opposite sides of the bulkhead. As with all hi.- h performance electrical connecting system which are used for aircraft or missile applications, the weight and ace SP reqiiirements of the systeir. must be held to a mim'mum level, the contact interfaces should be sealed and @the performance characteristics and reliability factors must be hi.-h as compared Nvith more ordinary applications. It is an object of the present invention to provide an improved interconnection wiring system. It is a further object to provide a modular wiring system capable of accommodating any desired number of wires. A still further object is to provide a modular wirin.- system having a minimum i3umber of component parts which can be assembl-,d to each other in different modes to achieve either feed-throligh wiring at a b,,ilkhead (i.e. interconnections of wires on opposite sides of the bulkhead) or conimom'n.of wires on one side of a bulkhead. A still further object is 1.0 provide an interconnectin.- wiring system which is environmentally sealed, which occupies a minimum amount of space, which is of minimum weight, and which, in general, satisfies the exacting requirements of aircraft or similar applications. Theso and other objects of the invention are achieved i-n a preferred embodiment comprising a plurality of individl,al modular units, each unit containing a plurality of pairs of contact sockets. When the modules are assembled in a wiring system for commoning wires on one side of a Patented July 15, 1969 2 bulkhead (a feed-to application), contact sock-ets are mounted in the modules in side-by-side parallel relationship The arrangement is such that any desired numbers of pairs of sockets can be electrically integral with each other so that a common electrical junction is obtained among the inserted contact pins of each group. The modules are cons' ructed in a manner such that the electrical contact areas are protected from the atmosphere. Furthermore, if two or more groups of contacts are mounted in an in'- 10 dividual module, each group is environmentally separated from the adjacent groups in the same module. The module units can also be assembled to each other in a manner such that they can be mounted in a bulkhead opening to permit feed through of conductors from one side of the 15 bulkhead to the other side. Again, commoning among a pluralty of cor@ductors on opposite sides of the bulkhead can be achieved by proper selection of the number of contacts which are electrically inte.-ral with each other. In the drawings: 20 FIGURE I is a fragmentary perspective view of a preferred form of an interconnection system in accordance with the invention showing the manner in which the parts are arran,-ed when it is desired to make common electrical connections on one side of a bulkhead or panel; 25 FIGURE 2 is a sectional side view of one of the modules of the interconnection system of FIGURE 1; FIGURE 3 is a view taken along the lines 3-3 of FIGURE 2; FIGURE 4 is a view similar to FIGURE 3 but illus30 tratin@ the positions of the parts prior to final assembly; FIGURE 5 is a plan view of a short section of blankecl strip from which contact sockets in accordance with the invention are formed; FIGURE 5A is a perspective view of the stock material 35 from which the strip of FIGURE 5 is blanked; FIGLTRE 6 is a perspective view of a short section of contact socket strip subsequent to forming of the sockets and prior to shortening cf the pitch of the strip; FIGURE 7 is a perspective -view of a short section of 40 socket strip after shortening of its pitch, the strip being used in this form for feed-through applications; FIGURE 8 is a perspective exploded view of an individual module assembly of the type used for commonin- a plurality of conductors; 45 FIGURE 9 is a plan view of a portion of the interconnection system of FIGURE 1 and illustrating the manner in which individual modules can be removed from the mouriting means; FIGURE 10 is a side view of a bulkhead feed-through 50 application of the invention; FIGURE 11 is a sectional side view illustrating the maniier in which the contact sockets are mounted in the modules for bulkhead feed-through applications; FIGURE 12 is a view taken along the lines 12-12 of 55 FIGURE II; FIGURE 13 is a perspective exploded view showing the manner in which the parts are assembled to produce the bulkhead feed-through module of FIGURE 11; and FIGURE 14 is a fragmentary perspective view of a (30 bulkhead feed-through system in accordance with the invention. FIGURE I shows an interconnection system in accordance with the invention for making common electrical 65 connections among a plurality of conductors on -one side of a panel 6. The interconnections are made by means of a plurality of individual modules 2 which are mounted as a stack in side-by-side relationship in a frame means comprising mountina. channels 4, these mounting channels 70 each having a web 8 and sidewalls 10, 12. The moanting channels may be secured -to the panel 6 by suitable fasteners as shown at 5.
[2]3,456,231 3 The individual modules 2 (FIGURES 2-4) each comprise a central body or housing 14 of a suitable rigid insulating material such as epoxy or dyal phthalate havin@ -a plate 16 bonded or otherwise secured to its lower side 17 and having a resilient sealing block 18 bonded to its 5 upper side 19, this sealin- block being of a resilient insulating material such as a silicon rubber. A plurality of contact-receiving cavities or passageways 24 extend through the block 18 and are in alignment with contact cavities 30 in the central body portion 14 of the module. 10 The cavities 20 extend downwardly from the upper side 22 of the sealing block 18 and have an upper portion as viewed in FIGURE 3 which is sinuous in cross-sections to define constricted neck portions 26. The lower portions of the cavities as shown at 28 are of cylindrical shape -Ind 15 comipunicate directly with the upper portions of the cavities 30 in the body portion 14. The constrictions 26 in the entrance passageways 24 have a width which is less than the diameter of the wire 64 to which an inserted contact pin 62 is crhnped so that after insertion of the ter- 20 minal pin into the block, the constricted portions 26 of the entrance passageways will bear against the wire to provide a sealing effect. The sealing block 18 is advantageously manufactured by a suitable molding process and is formed with thin 25 membrane-like walls 25 extending over, and closing off, the entrance portions of the passageways 24 in the block 18. When a terminal pin is inserted through any one of the passageways 24, this membrane or wall 25 is punctured but if a particular cavity in the module is not used in any 30 instance, the module will nontheless be sealed by virtue of the presence of the unbroken membrane 25. The contact receiving cavities 30 in the central housing portion 14 are adapted to receive contact sockets generally shown at 52 and described in further detail below. The 9,5 cavities 30 are of uniform diameter in their intermediate portions but have a reduced diameter portion at their upper ends as viewed in FIGURE 2 to define a downwardly facing shoulder 32 against which an inserted contact socket bears. The lower portions of the cavities 30 40 are somewhat enlarged as shown at 36 and open into a rectangular recess 34 in the lower end of the housin,@ portion 14. A barrier insert 38 (FIGURE 8) of compressible insulating material such as silicone rubber fits into the re- 45 cess 34 in the lower portion of the central housing 14 and has a plurality of openings 39 extending therethrough in alignment with the cavities in the housing portion 14. As is apparent from FIGURE 8, each openin,a 39 in the barrier insert 38 is in alignment with a pair of side-by- 50 side cavities 30 in the housing portion 14. The openings 39 are separated by transverse walls 40 which extend between the sides 42 of the barrier insert so that each pair of associated cavities in the central housing 14 is isolated from the next adjacent pair of cavities. The barrier insert 5,5 38 normally extends slightly beyond the side 17 of the central section 14 of the module (see FIGURE 4) and is compressed (FIGURES 2 and 3) by the closure plate 16 which is bonded to the face 17 as previously noted. When this plate 16 is bonded to the face 17 of the housing, the 60 projecting portion of the barrier insert 38 is compressed as shown at 38a thereby to provide a peripheral seal around the cavities extending through the module. The contact sockets 52 which are contained in the modules 2 are manufactured in the form of a continuous 65 strip from a laminated stock material (FIGURE 5A) having a base lamina 51 of beryllium copper or ot her high strength springy material and a contact lamina 49 of copper. The beryllilim copper lamina extends laterally 70 beyond the copper laraina on each side so that in the fmished contact sockets, the contact portion of each socket 52 and the current carrying portions of the strip consist of pure copper having a hi.-h electrical conductivity. The contact springs of the sockets and the pin retainers, on 75 4 the other hand, are of beryllium copper and have superior physical properties as will be explained below. Referring to FIGURE 5, the strip 49, 51 is blanked to produce a plurality of pairs of socket blanks indicated at 52' each of which is of generally rectangular shape and wbich is connected to a carrier strip 48' by neck portions 54' with the blanks 52' of each pair aligned with each other on opposite sides of the carrier strip. A central contact spring 60' is blanked from the strii) in the form of a tongue extending inwardly to,@@,ards the central carrier strip 48'. A pair of contact retaining springs 58' are blanked from the strip blank 52' on each side of the contact spring blanks 60'. The socket blanks 52' shown in FIGURE 5 are formed into cylinders as shown in FIGURE 6 havin- an axially extendin@- seam 56 with the retainer springs 58 disposed on each side of the seam and directed obliquely inwardly towards the socket axis. The contact springs 60 of the individual sockets, which are on the opposite sides from the seams, are likewise directed obliquely towards the axis of the sockets. It will be apparent from FIGURES 5 and 6 that in each contact socket, the copper limipa of the strip from which the sockets are formed is contained inside the sockets as a liner adjacent to the carrier strip and extends over, and covers, the carrier strip 48. The pitch of the strip of contact sockets (i.e. the spacing between adjacent sockets 52) shown in FIGURE 6 is shortened by inward forming of the sections of the carrier strip extending between adjacent pairs of sockets as shown at 70. This shortening operation results in a keystone-like shape Nvhich permits the strip to be used in the housing modules 2 as will be explained below. Where the invention is being practiced to achieve bulkhead feedthrough of conductors as shown in FIGURE 10, the strip is used in the form shown in FIGURE 7 with the contact sockets in axial alignment on opposite sides of the carrier strip. When the invention is practiced to achieve commoning of conductors on one side of a bulkhead as in FIGURE 1, the neck portions 54 of the sockets are bent as shown at 54b (FIGURE 8) so that theindividual pairs of sockets are in -side-by-side parallel relationship. When an individual module 2 is assembled, a section of strip in the form shown in FIGURE 8 is cut from a continuous length of strip and inserted as indicated into the module. Up to ten commonly connected contact sockets can be mounted in a single module by cutting off a length of five pairs of sockets as shown in FIGURE 8. These sockets are moved relatively through the barrier insert and into the cavities in the housing portion 14 of the module until their leading ends move against the shoulders 42 of the cavities which shoulders function as stops for the strip. When a ten socket length of strip is mounted in a module, the bridging portions 70 of the strip wiH extend over the walls 40 of the barrier insert and compress these walls as is illustrated in FIGURES 2 and 3. As previously noted, final assembly of the cover plate 16 to the module side 17 seals the module from the atmosphere. An advantage of the invention as described thus far is that an individual module can be fitted with various combinations of commonly connected sockets. For example, if it is desired to have five individual pairs of sockets in a module (that is, five pair electrically separated from each other but with the two sockets of each pair connected to each other) it is merely necessary to sever individual pairs of sockets from the strip by cutting the carrier strip on each side of the pair of sockets and discarding the folded portions 70 of the carrier strip. The individual connected pairs of sockets 52 are then fitted into a pair of side-by-side cavities 30 and the cover plate 16 is assembled to the module as previously described. In a module of this type, containing five separated pairs of sockets, the barrier walls 40 between the openings of the barrier insert 38 are not compressed by the carrier strip but these walls 40 bear against and are compressed
[3]3,456,231 5 by the surface of the plate 16 so that the separate pairs of commonly connected sockets are each sealed from each other. Other combinations, as regards the number of commonly connected sockets in an individual module, can be achieved by merely using the appropriate length of socket strip for the appropriate number of severed pairs of sockets. FIGURES 2 and 3 Mustrate a module having eight commonly connected sockets (which appear on the ri-,ht in FIGURE 2) and one pair of separate sockets (which appear on the left in FIGURE 2). The pair of commonly connected sockets which appear on the left in FIGURE 2 and which are shown in FIGURE 3 are sealed from th-. atmosphere and from the remaining sockets in the module by the compressed barrier wall indicated at 40a. Advantageously, the individual modules are provided with markin.- lines 72 on their sides 22 to delineate the commonly connected sockets in the module. Thus, in FIGURE 1, the module exploded from the channel has ten electrically common sockets therein. The module 2' in the channel contains two commonly connected sockets in combination with eight commonly connected sockets. The module 2" contains four commonly connected sockets and six commonly connected sockets, the commonly connected sockets in each module bein.- surrounded by the markin.- boundaries 72 as shown. The sockets 52 are dimensioned to receive contact pins 62 (FIGURE 3) which are crimped onto the end of conductors 64. The contact pins 62 are of a conventional type manufactured by screw machine operations and have a collar 66 integral therewith adjacent to their contact end portions 68. Upon insertion of an individual contact pin into one of the cavities in a module, the shoulder 65 defined by the lower side of the collar 66 moves a-,ainst the shoulder 53 defined by the copp.-r conductor material 49 of the contact socket and the retaining springs 58 of the socket lodged a.-ainst the shoulder 67 defined by the upper side of the coflar 66. The contact spring 60 of the socket bears a.-ainst the surface of the collar 66 so that the contact end portion 68 of the contact pin is pressed against the surface of the copper conductor material of the strip. The individual contacts can be removed from the modules by the use of a suitable extraction tool -which is inserted through the cavity in surrounding relationship to the wire 64, and pin until the end of the extraction tool moves against the shoulder 37 of th,- collar 66 whereby the retainer sprin-,s 58 are biased outwardly permitting withdra-,val of the contact and the extraction tool as a unit. Modules 2 in accordance with the invention can be mounted in any suitable manner on a bull-head or panel. FIGURE I shows a preferred mounting system which has the advantage of pennittin.- the removal of individual modules for s--rvicing or for other purposes without disassembly of the entire interconnection system. In accordance ,vith this mountin.@ system, the sidewalls 10, 12 are provided with spaced-apart projections in the form of inwardly formed ribs 74, the ribs on the sidewalls 10 being opposite to the ribs on the sidewah 12. These ribs are located a distance above the surface of the web 8 of the mountidg rail such that the downwardly facing sides of the ribs will bear a.-ainst tn@- led-,es 19 of the individual modules thereby preventing upward movement of the modules and removal from the rails. The spacing between adjacent ribs in th-- sidewalls is sli.-htly greater than the width of the individual modules so that when it is desired to remove a module, an entire row of modules can be slid until the module to be removed is disposed between adjacent ribs of the sidewalls. The module can then be moved upwardly from the rail in which it is mounted without disturbing the remaining modules in that particular rail as illustrated in FIGURE 9. The stock of modules in an individual rail or channel 4 is clamped therein by menns of a plate 76 the edges of which are received in grooves 80 in the sidewalls 10, 12 adjacent to the web 8. Plate 76 has an obliquely upwardly extending ton,-Ue 78 which bears against the end of modtile of the 6 stack and a clampin- screw 82 is threaded through this plate so that upon tightening this screw, it becomes impossible to -move the clamping plate or the modules in the mounting rail. The individual modules have interfitting ribs and grooves indicated at 13 and 15 on opposite sides of the housing portion 14. Thus the rib 15 of each module is received in the groove 13 of an adjacent module thereby to prevent removal of an individual module unintentionally. The modules must thus be separated from each other before removal can be accomplished as also illus10 trated in FIGURE 9. If desired, the sidewalls 10 of the mounting rails can be provided with longitudinally extending grooves 84 adapted to receive similarly shaped ribs 86 on the out15 side surface of the sidewall 12, of an immediately adjacent rail. As shown in FIGURE 1, this arrangement permits two or more rails to be interlocked thus forming an assembly of rails. An assembly of this type can be mounted in a suitable surrounding frame if desired. 20 FIGURES 10-14 show the manner in which the parts of the previously described interconnection system can be ass,-;mbled to each other and used for bulkhead feedthrough applications. In FIGURE 10, a module unit 14a, 14b is shown as being mounted between rails, described 25 below, which in turn are mounted in an opening in a panel 90. This wiring arrangement permits the achievement of interconnections among conductors 64a, extending from the right in FIGURE 10, and conductors 64b, extending from the left, towards the panel 90. 30 Individual modules for this feed-through arrangement are composed of a pair of the previously identified housing sections 14 and identified in FIGURE 13 as 14a, 14b. Each housing section 14a, 14b is provided with a resilient sealing block 18a, 18b as previously described and a 35 barrier insert 100 which is comparable to, but which differs slightly from, the barrier insert 38 previously described. Particularly, the barrier inserts 100 are provided with a number of openings 102 equal to the number of cavities 30 and in alignment with the cavities 30 in the 40 housing sections 14a, 14b. As with the barrier inserts 33, the barrier inserts 100 are of compressible material and normally project slightly beyond the sides 17 of the module housings 14a, 14b. The tern-iinal strip in this embodiment is employed in its unbent condition, that is, with the contact sockets of 45 each pair of contact sockets in axial alignment with each other on opposite sides of the carrier strip as shown in FIGURES 2:and 13. To assemble the module, the parts are aligned with each other as shown in FIGURE 13 and the upwardly directed contact sockets are inserted into the 50 cavities in the upper housing section 14b while the downwardly directed contact sockets are inserted into the corresponding cavities in the housing section 14a. Again, various interconnection arrangements can be achieved by proper selection of the length of carrier strip. In FIG55 URE 13, one section of contact socket strip is shown of a len.-th such that it contains three upwardly directed soclets and three downwardly directed sockets and another section is shown having two upwardly directed contact sockets and two downwardly directed sockets. 60 N"en these two sections of socket strips are inserted into the composite module, the arrangement will be as shown in FIGURE II; in this figure, the three pairs of contact sockets in the upper portion (as viewed in FIGURE 11) of the module are commonly connected while the two 65 pairs of sockets in the IoNver portion of the module are separate from the upper sockets but are electrically connected to each other. It will be seen in FIGURE II that the common contact sockets in the upper portion of the module are environmentally sealed from the sockets of 70 the lower portion of the module by the compressed mating faces of the barrier insert as indicated at 104. After assembly of the contact sockets strip to the module housing as indicated in FIGURE 13, the housing sections 75 14a, 14b are bonded or otherwise secured to each other
[4]7 along their mating faces 17a, 17b to produce the composite feed-through module shown in FIGURES 11 and 12. Modules of this type are mounted between the opposing faces of the rails 96, 98 as shown in FIGURES 10 and 14. The inner surfaces of the rails 96, 98 are provided with inwardly formed ribs or bosses 74a, 74b which hold the modules in position. As with the previously described embodiment, the ribs 74a, 74b are discontinuous thereby to permit removal of the individual modules from the stack. The modules are retained between the rails 96, 98 by means of clamping devices 106. Each of these clamping devices comprise a pair of the previously described plates 76 disposed against each other aild having their ends extending into grooves $Oa of the opposed faces of the rails 96, 98. The tongues 78a of the clamps bear against the sides of the end modules of the stack to hold the stack against movement. Screws threaded through one of the plates 76 of each clamp bear against the other plate and function to wedge the plates apart thereby to lock the ends of the plates in the grooves 80a. The rails 96, 98 are held in spaced-apart relationship by spacers IL08 having flanges 110 on their sides which are secured to th.- rails by fasteners 114. An additional flange IL12 is provided to permit the assembly to be clamped to a panel with the modules accessible from either side of the panel throu,-h a suitable opening. Under some circumstances, it may be desirable to provide additional clamps 108a intermediate the ends of the rails 96, 98. For example, if interconnection systems has a relatively large number of modules, the modules can be arran-,ed in several stacks with one or more intermediate clamping plates 103a being provided to support the rails intermediate their ends. The embodiment of the invention shown in FIGURES 10-14 to form common electrical connections to mounting the modules against a mounting panel in an orientation such that the axes cavities in the modules extend parallel to the plane of the panel. This arrangement can be achieved, for example, by mounting either one of the rails 96, 98 on the panel. Several mounting options are thence available to the user who can select the system that best satisfies his needs. A salient advantage of the invention is that a wide variety of interconnection arrangements for both feedthrough and commoning applications can be achieved with a relatively low number of parts. The terminal strip as shown in FIGURE 6 as shortened by formation of the keystone shap.-d folds 70 and is used with the contacts in alignment with each other for feed-throu-h applications or with the contacts bent through a 90' an.-le for commoning appl,.cations. The housing sections 14 can be used either for feed-through applications or feed-to applications as can the sealing blocks 18. A further significant feature of the invention is that each group of commonly connected contact sockets are mechanically and electrically integral with each other and in the disclosed embodiment electrical contact is made with the copper conductin.- strip in the socket strip. The fact that the contact springs 60 in the contact sockets are integral with the socket strip is advantageous in that a redundant contact between the pins and the sockets is achieved. Thus, if contact between the end of a pin and the copper portion of the socket should be lost for any reason (e.g. vibration, presence of foreign matter, etc.) there would stib be electrical contact via the contact spring 60 and the collar 66 of the pin. Changes in -construction will occur to those skflled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of ihustration only. What is
