Automated assembly of connector to cable having twisted wire pairs

Information

  • Patent Grant
  • 6370769
  • Patent Number
    6,370,769
  • Date Filed
    Wednesday, October 27, 1999
    25 years ago
  • Date Issued
    Tuesday, April 16, 2002
    22 years ago
Abstract
A cable having at least two twisted wire pairs, each of the wires in the twisted wire pairs having wire jacket with a respectively different color, is automatically assembled by automatically detecting the colors of the wire jackets and automatically positioning the wires of the twisted wire pairs in a predetermined sequence based on the colors of the wire jackets. A machine vision system is used for detecting the colors of the wire jackets. A connector is then automatically attached to the automatically positioned wires. The connector may be a 110 connector, a D8GS connector, an RJ45 connector or an RJ11 connector.
Description




BACKGROUND OF THE INVENTION




The present invention relates to the manufacturing of electrical cables and, more particularly, the automated assembly of electrical cables having at least one twisted pair of wires.




As used herein and in the claims, a “cable” is a length of insulated wire or wires, also referred to as conductors, terminated on at least one of its ends with an interface, also referred to as a termination, having a housing which allows access to the wire. Usually, a cable has terminations on both of its ends, but such terminations need not be of the same type. A cable is also referred to as a cord.




Electrical signal transmission cables for connecting pieces of equipment are of two forms: cables in flat flexible form having conductors always in the same position, or cables with twisted pair conductors.




A cable with unshielded twisted pairs (UTP) is terminated with a connector such as a


110


connector, a D8GS connector, an RJ45 connector or an RJ11 connector. RJ45 connectors and RJ11 connectors are sometimes used with modular cords. Selection of the type of connector for a cable is based on the performance levels needed for the intended use.





FIGS. 4 and 8

show two piece type 110 connector


200


and four piece type 110 connector


300


, respectively. 110 connectors are used for patching between communication blocks for data and voice.





FIG. 20

shows D8GS connector


400


. D8GS connectors are used for high speed data transmission.





FIG. 24

shows RJ45 connector


500


. RJ45 connectors are used to connect voice and data communication equipment with RJ45 ports. An RJ11 connector is similar to an RJ45 connector except that the RJ11 connector is used with a single twisted pair while the RJ45 connector is used with four twisted pairs.




The size and shape of the housing of a D8GS, RJ45 and RJ11 connector is different than that of the housing of a 110 connector, and accordingly, the ordering of wires is different when assembled.




Each of the connectors in

FIGS. 4

,


8


,


20


and


24


may be used with cable


100


.




For clarity in the drawings, only reference numerals for the first and last of comparable elements are sometimes shown.





FIG. 1

shows cable


100


having four twisted wire pairs. Cable


100


includes jacket


111


and wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


formed into a first twisted wire pair including wires


120


and


130


, a second twisted wire pair including wires


140


and


150


, a third twisted wire pair including wires


160


and


170


, and a fourth twisted wire pair including wires


180


and


190


. Each pair is twisted to reduce the cross-talk between the wires in the pair. The twist rate is different on each pair to further reduce cross-talk between pairs. The length of cable


100


ranges from a few feet to about 33 feet.




Jacket


111


is circular in cross section and is typically formed of flame retardant PVC or another plastic or insulative material. Jacket


111


functions as an outer cover to insulate the twisted wire pairs inside.




Insulating wire jackets


122


,


132


,


142


,


152


,


162


,


172


,


182


,


192


are jackets for conductors


124


,


134


,


144


,


154


,


164


,


174


,


184


,


194


, respectively, and have respectively different colors for identification. Usually, jacket


122


is dark brown, jacket


132


is light brown, jacket


142


is dark blue, jacket


152


is light blue, jacket


162


is dark green, jacket


172


is light green, jacket


182


is orange and jacket


192


is white.





FIG. 2

shows an enlarged view of wire


120


in FIG.


1


. Wires


125




a


-


125




g


are combined together, typically having one central wire and the remaining wires wrapped around the central wire, and covered by insulating jacket


122


to form multi-conductor wire


120


. The number of conductors inside a wire varies depending on the gauge. Generally, a plurality of thin conductors provides better conductivity with larger surface area than a single conductor, which improves transmission quality for high frequency signals. Also multi-conductor wires bend more easily and absorb mechanical load better than single conductor wires. Wires


130


,


140


,


150


,


160


,


170


,


180


,


190


have a similar structure to wire


120


.





FIG. 3

shows cable


10


having two pairs of twisted wires. Cable


10


includes jacket


12


and wires


20


,


30


,


40


,


50


formed into a first twisted wire pair including wires


20


and


30


, and a second twisted wire pair including wires


40


and


50


. Cable


10


is similar to cable


100


in

FIG. 1

except for its number of twisted wire pairs.





FIG. 4

shows assembled two piece type 110 connector


200


which comprises first housing member


202


, second housing member


204


and cable


100


. Cable


100


and first housing member


202


are assembled first, then second housing member


204


is joined to first housing member


202


to form two piece type 110 connector


200


. Members


202


,


204


are shown in details in

FIGS. 5 and 6

, respectively.





FIG. 5

illustrates first housing member


202


of two piece type 110 connector


200


. First housing member


202


has support members


206


,


208


,


210


. Members


206


and


208


receive cable


100


. Member


210


functions as a cable jacket stop when cable


100


is mounted on members


206


,


208


. Upstanding posts


216




a


-


216




g


define gaps


220




a


-


220




h


for each of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


. Insulation displacement contact (IDC) grooves


217




a


-


217




h


receive IDCs


246




a


-


246




h


of second housing member


204


of FIG.


6


. Posts


218




a


-


218




g


meet and separate each of IDCs


246




a


-


246




h


of contacts


242




a


-


242




h


of second housing member


204


of

FIG. 6

, so that it is easier for IDCs


246




a


-


246




h


to cut insulation


122


,


132


,


142


,


152


,


162


,


172


,


182


,


192


of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


when second housing member


204


is mated to first housing member


202


. Latching arms


224




a


-


224




c


and press fit members


212




a


-


212




b


engage with corresponding shoulders and latching arms in second housing member


204


when the two housing members are mated. Openings


214




a


-


214




b


around press fit members


212




a


-


212




b


serve as complementary recesses to receive corresponding latching arms of second housing member


204


. Gap spacers


222




a


-


222




d


are located next to latching arms


224




a


-


224




c


to maintain a space between first and second housing members


202


,


204


when they are assembled.





FIG. 6

illustrates second housing member


204


of two piece type 110 connector


200


. Second housing member


204


has cable receiving end


230


and upstanding projection


232


. Projection


232


functions as a strain relief to overlying cable


100


when cable


100


is mounted thereon. Upstanding posts


238




a


-


238




h


are provided to press wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


when two housing members


202


,


204


are assembled together. Latching arms


234




a


-


234




d


are provided for engaging with press fit members


212




a


-


212




b


of first housing member


202


. Between latching arms


234




a


-


234




d


, openings


236




a


-


236




b


are respectively provided to receive press fit members


212




a


-


212




b


of first housing member


202


. Openings


248




a


-


248




c


are provided as respective shoulders for latching arms


224




a


-


224




c


of first housing member


202


. Slots


240




a


-


240




h


are provided to receive the blades of contacts


242




a


-


242




h


. IDCs


246




a


-


246




h


are located at the end of contacts


242




a


-


242




h


and cut insulation


122


,


132


,


142


,


152


,


162


,


172


,


182


,


192


of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


, respectively, when assembled with first housing member


202


.




A conventional assembling sequence of first housing member


202


with cable


100


will now be described.




An assembly worker prepares cable


100


by removing jacket


111


from an end of cable


100


to expose pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


of wires of cable


100


. The assembly person appropriately relocates the pairs depending on the colors of the jackets, and positions cable


100


in first housing member


202


. Jacket


111


of cable


100


seats in slots


206


,


208


and ends just before slot


210


. Starting from slot


210


, the worker routes each of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


and respectively inserts them into gaps


220




a


-


220




h


. After appropriate positioning, the assembly worker trims the ends of the wires using a suitable flush cutting tool to ensure that the remaining wire ends are uniformly positioned between upstanding posts


216




a


-


216




h


and posts


218




a


-


218




g


of first housing member


202


. Next, the worker aligns and presses members


202


and


204


together, thereby inserting IDCs


246




a


-


246




h


of contacts


242




a


-


242




g


of second housing member


204


. IDCs


246




a


-


246




h


pierce insulation


122


,


132


,


142


,


152


,


162


,


172


,


182


,


192


of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


when assembled with first housing member


202


. The worker tries to maintain the twist rates between the twisted wire pairs, shown in

FIG. 1

, throughout the assembly process.





FIG. 7

shows first housing member


202


assembled with cable


100


according to the assembly method described above. As indicated in

FIG. 7

, the original twist rates on each of the twisted wire pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


is maintained as much as possible by the assembly worker during manual assembly. The end of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


are positioned and trimmed right after posts


218




a


-


218




g


where IDCs


246




a


-


246




h


of second housing member


204


cut insulation


122


,


132


,


142


,


152


,


162


,


172


,


182


,


192


of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


.





FIGS. 8A-8F

show the components of four piece type 110 connector


300


before assembly. Four piece type 110 connector


300


is designed to terminate a cable having four twisted pairs and to mate with a 110-type connecting block. Four piece type 110 connector


300


comprises base member


302


, contact base


308


, contact


309


(only the four top contacts are shown), first housing member


304


and second housing member


306


. Base member


302


mounts cable


100


and is fitted between first housing member


304


and second housing member


306


. Base member


302


has channels


317




a


-


317




h


for receiving wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


. Channels


317




a


-


317




h


of base member


302


provide routing paths for individual wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


, respectively. Base member


302


is also provided with IDC grooves


318




a


-


318




h


to receive the IDCs of contact


309


. Contact base


308


is assembled with contact


309


, and then inserted into base member


302


in which cable


100


is mounted. First housing member


304


, second housing member


306


, contact base


308


and base member


302


are usually made from a non-conducting injection-molded plastic, such as polycarbonate, ABS, or PVC, while contacts


309


are made from a conducting material, such as stamped phosphor bronze plated with nickel and gold. Four piece type 110 connector


300


is designed to reduce the variation of cross talk throughout assembled connectors caused by lack of the control of routing of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


during an assembly process. Members


302


,


304


,


306


,


308


are shown in detail in

FIGS. 9

,


10


,


11


and


12


, respectively.





FIG. 9

illustrates base member


302


of four piece type 110 connector


300


. Base member


302


has slot


310


to receive cable


100


. Slot


312


functions as a cable jacket stop when cable


100


is mounted in slot


310


. Openings


314




a


,


314




b


form a through-space for latching arms and press fit members of first and second housing members


304


,


306


when they are mated. Channels


317




a


-


317




h


define routing paths for wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


. Upstanding posts


316




a


-


316




g


are located along front edge


320


of base member


302


to define IDC grooves


318




a


-


318




h.







FIG. 10

illustrates contact


309


placed on the top side of contact base


308


. Contact base


308


also receives four bottom contacts (not shown) on its bottom side. The designs of the top and bottom contacts are identical. As configured for assembly, contact


309


is rotated


180


degrees about its longitudinal axis with respect to the bottom contact. IDCs


322




a


-


322




d


of contact


309


and the corresponding IDCs of the bottom contact (not shown) cut and terminate insulation


122


,


132


,


142


,


152


,


162


,


172


,


182


,


192


of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


. Grooves


328




a


-


328




d


receive blades


324




a


-


324




d


of contact


309


. Openings


326




a




326




d


are provided for latching arms


338




a


-


338




d


of first housing member


304


, shown in FIG.


11


.





FIG. 11

illustrates first housing member


304


of four piece type 110 connector


300


. After base member


302


is assembled with contact base


308


, first housing member


304


is attached to the bottom of the assembled members


302


and


308


. First housing member


304


also opposes second housing member


306


. Slot


330


is a receiving space for cable


100


. Press fit members


332




a


-


332




b


fit with latching arms


354




a


-


354




d


of second housing member


306


. Openings


334




a


-


334




b


,


336




a


-


336




d


serve as complementary recesses and shoulders for latching arms


354




a


-


354




b


,


354




c


-


354




d


,


358




a


-


358




d


, respectively, of second housing member


306


. Grooves


340




a


-


340




h


fit with the vertically positioned blades of contacts


324




a


-


324




h


of contact member


308


. Upstanding protrusions


338




a


-


338




d


press against the surface of the blades of contacts


324




a


-


324




h


of contact member


308


.





FIG. 12

illustrates second housing member


306


of four piece type 110 connector


300


. Second housing member


306


is attached to the top of base member


302


after base member


302


is assembled with contact member


308


and first housing member


304


. Cable receiving end


350


and upstanding projection


352


receive cable


100


. Upstanding projection


352


functions as a strain relief to overlying cable


100


. Latching arms


354




a


-


354




d


and


358




a


-


358




d


are provided for engaging with corresponding press fit members


332




a


-


332




b


and openings


336




a


-


336




d


of first housing member


304


, respectively. Openings


356




a


-


356




b


are provided to receive press fit members


332




a


-


332




b


of first housing member


304


. Grooves


364




a


-


364




h


are provided to fit with one side of the vertically positioned blades


324




a


-


324




h


of contacts


309


. Upstanding protrusions


362




a


-


362




d


are provided to press against the surface of blades


324




a


-


324




h


of contact


309


.




Assembly of four piece type 110 connector


300


with cable


100


is now described.





FIG. 13

is a view of base member


302


assembled with cable


100


. An assembly worker prepares cable


100


by removing jacket


111


from an end of cable


100


to expose twisted pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


of cable


100


. Jacket


111


of cable


100


is placed on slot


310


of base member


302


and ends at slot


312


of base member


302


. Starting from slot


312


of base member


302


, the worker routes each of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


and inserts them into the appropriate one of channels


317




a


-


317




h


of base member


302


. The assembly worker appropriately relocates the pairs depending on the colors of the jackets, and positions cable


100


in base member


302


. The assembly worker tries to maintain the twist rates between twisted pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


of cable


100


throughout the assembly process.





FIG. 14

is a view of the sub-assembly of

FIG. 13

after wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


have been positioned within IDC grooves


318




a


-


318




h


of base member


302


. The assembly worker guides wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


through channels


317




a


-


317




h


and bends the wires at front edge


320


of base member


302


. Pyramidal structures at the top of upstanding posts


316




a


,


316




c


,


316




e


,


316




g


assist in the separation of individual wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


from twisted pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


of cable


100


as the twisted pairs are inserted into IDC grooves


318




a


-


318




h.






After appropriate positioning, the assembly worker trims the ends of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


using a suitable flush cutting tool.

FIG. 15

is a view of the sub-assembly of

FIG. 14

after wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


have been trimmed to terminate at the bottom of base member


302


.





FIGS. 16A and 16B

illustrate how contact base


308


loaded with contact


309


(not shown in

FIG. 16A

, see

FIG. 10

) is mated to base member


302


loaded with cable


100


. After base member


302


is assembled with cable


100


and contact base


308


is assembled with contact


309


, the assembly worker mates the assembly of contact


309


and contact base


308


to the assembly of base member


302


and cable


100


. IDCs


322




a


-


322




h


of contact


309


are received within IDC grooves


318




a


-


318




h


of base member


302


at right angle to wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


, cutting insulating jackets


122


,


132


,


142


,


152


,


162


,


172


,


182


,


192


of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


, respectively.





FIGS. 17 and 18

illustrate how first housing member


304


and second housing member


306


are assembled onto the sub-assembly of FIG.


16


. First housing member


304


and second housing member


306


are attached to the bottom and top of the sub-assembly of

FIG. 16

, respectively.





FIG. 19

is a view of the completed assembly of four piece type 110 connector


300


. The worker needs to align and mate the latching arms, press fit members and openings of the connector housings repeatedly by hand. Alternatively, a manually operated press may be employed.





FIG. 20

shows a view of assembled D8GS connector


400


. D8GS connector


400


comprises first housing member


402


and second housing member


404


, and is used with cable


100


. Members


402


,


404


are shown in detail in

FIGS. 21 and 22

, respectively.





FIG. 21

is a detailed view of first housing member


402


of D8GS connector


400


. Cord input aperture


410


receives and guides cable


100


and strain relief


412


receives and presses cable


100


when an assembly worker inserts cable


100


into first housing member


402


for assembly. Shoulder


414


is provided to block jacket


111


when cable


100


is inserted into first housing member


402


. Gaps


419




a


-


419




h


are provided to fix the wire ends when cable


100


is inserted into first housing member


402


. Latching arms


416




a


,


416




b


mate with openings


424




a


-


424




b


of second housing member


404


as shown in FIG.


22


. Lever


418


of

FIG. 21

is provided to push lever


426


of second housing member


404


of

FIG. 22

when D8GS connector


400


is unplugged from communication equipment (not shown).





FIG. 22

illustrates second housing member


404


of D8GS connector


400


. Second housing member


404


is provided with cavity


420


to receive first housing member


402


which is assembled with cable


100


. IDCs


422




a


-


422




h


are provided to receive and cut insulation


122


,


132


,


142


,


152


,


162


,


172


,


182


,


192


of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


, respectively. Openings


424




a


-


424




b


are provided to receive latching arms


416




a


-


416




b


of first housing member


402


.





FIG. 23

is a view of first housing member


402


assembled with cable


100


. An assembly worker removes jacket


111


of cable


100


from an end of cable


100


to expose the pairs of wires


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


of cable


100


. The worker inserts the exposed end portion of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


through cord input aperture


410


of first housing member


402


until the leading end of jacket


111


abuts shoulder


414


formed internally in first housing member


402


.




The worker then places the twisted pairs in grooves


419




a


-


419




h


, respectively, of first housing member


402


. The worker then trims the wire ends. The wire placement and trimming follows a generally similar sequence as shown in

FIGS. 13-15

. The worker then mates second housing member


404


to first housing member


402


, as assembled with cable


100


, by manually aligning IDCs


422




a


-


422




h


of second housing member


404


with wire ends fixed at gaps


419




a


-


419




h


of first housing member


402


.





FIG. 24

shows a view of RJ45 connector


500


, assembled with cable


100


. RJ45 connector


500


comprises plug


502


, management bars


508


,


510


(not shown) and contact member


506


. Management bars


508


,


510


are provided to align wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


before the wires are inserted into plug


502


. Plug


502


is provide with a cavity (not shown) to receive wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


. Strain relief


504


of plug


502


is provided to release tension exerted upon overlying cable


100


. Metal contact


506


conducts signal from wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


to the communication equipment (not shown) when RJ45 connector


500


is mated to the plug of the communication equipment.





FIGS. 25A

,


25


B illustrate management bars


508


,


510


, respectively. Management bar


508


has grooves


509




a


-


509




d


and holes


509




c


-


509




h


. Management bar


510


has a similar structure to management bar


508


. Each of the holes and grooves of management bars


508


,


510


is used with a predefined colored wire jacket of cable


100


.




The assembly process of RJ45 connector


500


is now described.




An assembly worker prepares cable


100


by removing jacket


111


from an end of cable


100


to expose the wire pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


of cable


100


. The assembly worker orients cable


100


and sets wire pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


into a predetermined sequence depending on the color of insulating jackets


122


,


132


,


142


,


152


,


162


,


172


,


182


,


192


. The worker uses appropriate tools to spread jacket


111


of cable


100


so that wire pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


lay beside each other. The worker then untwists each of wire pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


and arranges the untwisted wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


into two rows for ease of wire insertion into grooves


509




a


-


509




d


and holes


509




e


-


509




h


of management bar


508


and corresponding grooves and holes of management bar


510


. The assembly worker inserts the arranged wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


into the grooves and holes of the management bars


508


,


510


according to a predetermined sequence. The assembly worker then trims any excess wire at the edge of outer management bar


510


and inserts wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


, as assembled with management bars


508


,


510


, into plug


502


.





FIGS. 26A

,


26


B show wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


assembled with management bars


508


,


510


just before insertion into plug


502


.




Due to the complex nature of the assembly process, it is typical for assembly workers to make mistakes throughout the assembly steps. The assembly workers create differences from cable to cable in untwisting twisted wire pairs, differences from cable to cable in how forcefully the wires are placed into slots of the connector housing, and errors in placing the correct color wires in slots of the connector housing. The assembly workers sometimes fail to bring the wires out to the edge of the connector housing.




While cables with flat flexible cables are known to be automatically assembled, twisted wire pair cables have always been assembled manually due to the complex nature of the assembly process discussed above. Nevertheless, automated assembly of twisted wire pair cables is desirable to reduce performance variations between cables.




SUMMARY OF THE INVENTION




In accordance with an aspect of this invention, there is provided a method of and an apparatus for automatically assembling a cable having at least two twisted wire pairs, each of the wires in the twisted wire pairs having a wire jacket with a respectively different color. The colors of the wire jackets are automatically detected and the twisted wire pairs are automatically positioned in a predetermined sequence based on the colors of the wire jackets.




A machine vision system is used to detect the colors of the wire jackets. A pin is utilized to automatically sequence the twisted wire pairs. Connector housings are automatically attached to the sequenced twisted wire pairs. The connector may be a 110 connector, a D8GS connector, an RJ45 connector, an RJ11 connector or other connector designed for automatic assembly.




In accordance with another aspect of this invention, there is provided a method of and an apparatus for assembling a cable having at least two twisted wire pairs, each of the wires in the twisted wire pairs having a wire jacket with a respectively different color. The colors of the wire jackets are automatically detected and the wires of the twisted wire pairs are automatically positioned in a predetermined sequence based on the colors of the wire jackets.




It is not intended that the invention be summarized here in its entirety. Rather, further features, aspects and advantages of the invention are set forth in or are apparent from the following description and drawings.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a view of cable


100


having four twisted wire pairs;





FIG. 2

is an enlarged view of wire


120


in

FIG. 1

;





FIG. 3

is a view of cable


10


having two pairs of twisted wires;





FIG. 4

is a view of an assembled two piece type 110 connector


200


with cable


100


;





FIG. 5

illustrates first housing member


202


of two piece type 110 connector


200


;





FIG. 6

illustrates second housing member


204


of two piece type 110 connector


200


;





FIG. 7

a view of first housing member


202


assembled with cable


100


;





FIGS. 8A-8F

depict the components of four piece type 110 connector


300


;





FIG. 9

illustrates base member


302


of four piece type 110 connector


300


;





FIG. 10

illustrates contact base


308


and four top contact


309


four piece type


110


connector


300


before assembly;





FIG. 11

illustrates first housing member


304


of four piece type 110 connector


300


;





FIG. 12

illustrates second housing member


306


of four piece type 110 connector


300


;





FIG. 13

is a view of base member


302


assembled with cable


100


;





FIG. 14

is a view of the sub-assembly of

FIG. 13

after the wires of cable


100


are inserted into IDC grooves of base member


302


;





FIG. 15

is a view of the sub-assembly of

FIG. 14

after the end of the wires of cable


100


have been trimmed;





FIG. 16A

is a view of contact base


308


assembled with contact


309


;





FIG. 16B

is a view of the sub-assembly of

FIG. 15

;





FIG. 17

illustrates the sub-assembly of

FIG. 16

being assembled with first housing member


202


;





FIG. 18

illustrates the sub-assembly of

FIG. 17

being assembled with second housing member


204


;





FIG. 19

is a view of completed assembly of four piece type 110 connector


300


;





FIG. 20

is a view of assembled D8GS connector


400


;





FIG. 21

is a view of first housing member


402


of D8GS connector


400


;





FIG. 22

is a view of second housing member


404


of D8GS connector


400


;





FIG. 23

is a view of first housing member


402


assembled with cable


100


;





FIG. 24

is a view of RJ45 connector


500


;





FIG. 25A

is a view of first management bar


508


of RJ45 connector


500


;





FIG. 25B

is a view of second management bar


510


of RJ45 connector


500


;





FIG. 26A

is a view of plug


502


of RJ45 connector


500


;





FIG. 26B

is a view of cable


100


assembled with management bars


508


,


510


just before insertion into plug


502


;





FIG. 27

is a chart of automatic assembly line


600


for two piece type 110 connector


200


;





FIG. 28

is a flow chart of an automatic assembly procedure of two piece type


110


connector


200


for one embodiment;





FIGS. 29A and 29B

are views of pallet


700


and main body


702


of pallet


700


, respectively;





FIG. 30

is a view of stripped cable


100


mounted on pallet


700


;





FIG. 31

is a view of clamp


720


and pin


722


working with cable


100


mounted on pallet


700


;





FIG. 32

is a view of presser


728


working with cable


100


mounted on pallet


700


;





FIG. 33

is a view of machine vision system


730


and collet style chuck


735


working with cable


100


mounted on pallet


700


;





FIG. 34

is a view of blocker


727


of presser


728


pressing twisted wires of cable


100


;





FIG. 35

is a view of machine vision system


730


, collet style chuck


735


and pin


740


working on cable


100


mounted on pallet


700


;





FIG. 36

is a view of the sequenced wire pairs of cable


100


on pallet


700


;





FIG. 37A

illustrates movable surfaces


710


,


711


being detached from movable body


704


of pallet


700


;





FIG. 37B

is a magnified view of movable surfaces


710


,


711


of pallet


700


;





FIG. 38

is a view of sequenced wires of cable


100


on pallet


700


;





FIG. 39

is a view of first feeder


750


holding first housing member


202


of two piece type 110 connector


200


placed on top of the sequenced wires as in

FIG. 38

;





FIG. 40

is a view of first feeder


750


mated to pallet


700


loaded with the sequenced wires of cable


100


;





FIG. 41

is a view of second feeder


760


holding second housing member


204


placed on the bottom of first feeder


750


as in

FIG. 40

; and





FIG. 42

is a flow chart of an automatic assembly procedure of two piece type


110


connector


200


for another embodiment.











DETAILED DESCRIPTION




A technique of automatically assembling twisted wire pair cables is advantageously applied with conventional 110 connectors, D8GS connectors, RJ45 connectors and RJ


11


connectors.




Manufacturing cost has been a factor in deciding whether to develop and utilize an automated assembly system or to continue using a manual assembly system. Purchasing agents usually purchase cords based on lowest price yet expect to receive reliable performance, that is, purchasers are reluctant to pay for superior performance of some suppliers' cords. As a result, reducing manufacturing cost while maintaining high quality of cords has been an issue.




Manual assembly, however, increases electrical performance variation between cables. Electrical performance variation between cables introduces error into the signal carried on the cable, particularly at LAN rates of around 500 MHz, because the communication equipment is impedance-matched to an “ideal” cable, whereas the performance of an actual cable varies significantly from cable to cable for the reasons discussed above. Even for expensive communication systems, people often buy a cheaper cable and then blame errors introduced by the cheaper cable on the communication system.




A machine vision system that is able to deal with the complex nature of the twisted wire pair cables and be cost-effectively applied to the automation of twisted wire pair cable assembly has become available only within the last few years. In particular, the resolution of machine vision systems has been improved within last few years to a degree that such systems can now cost-effectively distinguish the colors and position of the twisted wire pairs.




Recently available machine vision systems are used to distinguish colors and relative positions of wire jackets automatically, thereby ensuring uniformity in assembly, such as the degree of untwisting of paired wires between cables, which in turn reduces performance variations between cables.




The present automated assembly technique may also be applied to flat cable connectors.




An advantage of cables produced using the present technique is improved performance uniformity, i.e., less electrical variations from cable to cable than with manually assembled cables. When an automatically assembled cable is used with equipment such as a patch panel, the equipment can be impedance matched to the cable's characteristics by the equipment manufacturer, rather than the end-user, improving overall performance results. The improved performance uniformity throughout connectors of the same kind also helps to customize communication links in private applications because users can readily change connections without degrading performance of the communication links.





FIG. 27

is a chart representing assembly line


600


for assembling two piece type


110


connector


200


. It will be appreciated that the present method can also be applied in other manufacturing configurations. One of ordinary skill will understand how to adapt the design of assembly line


600


depending on the yields and affordability of the machines used therein. Additionally, although most of the functions of assembly line


600


are shown as entirely automated, in other embodiments some of the functions may be performed manually.




Automatic assembly of two piece type connector


200


is now described.





FIG. 28

is a flow chart of an assembly procedure for one embodiment. The flow chart of

FIG. 28

will be explained assuming that two piece type 110 connector


200


is being assembled.




At step


805


of

FIG. 28

, a predetermined length of cable


100


is uncoiled from a reel and cut. A jacket remover removes a portion of jacket


111


at each end of cable


100


. The unreeling, cutting and removing are performed at station


610


. Station


610


of assembly line


600


includes a decoiler (not shown) for unreeling cable


100


, measuring the cable length and cutting cable


100


. Station


610


also includes a jacket remover (not shown) for stripping jacket


111


of cable


100


.





FIG. 29A

is a view of pallet


700


. Pallet


700


is a rectangular surface loaded on assembly system conveyer


699


which serves to move pallet


700


in the direction indicated by arrow


698


. After a length of cable


100


is cut, cable


100


is placed on the surface of pallet


700


. U-shaped clip


701


is adapted to restrain cable


100


from falling off of pallet


700


. The ends of cable


100


are placed on main bodies


702


A,


702


B, respectively. Main bodies


702


A,


702


B are identical in structure and are hereafter referred to as main body


702


.





FIG. 29B

illustrates main body


702


of pallet


700


on which cable


100


is mounted after the unreeling, cutting and stripping operation at step


805


. Pallet


700


is moved through stations


610


,


620


,


630


,


640


,


650


,


660


,


670


of assembly line


600


. Pallet


700


has main body


702


for mounting cable


100


and movable body


704


for manipulating the twisted wire pairs and the wires of the twisted wire pairs. Main body


702


is provided with groove


706


to mount cable


100


. Movable body


704


is free to move along the direction indicated by arrow


707


, thereby adjusting the height of movable body


704


and improving access to wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


. Grooves


950




a


-


950




d


are provided to guide the twisted pairs of cable


100


after jacket


111


has been stripped from cable


100


. Grooves


708




a


-


708




h


are provided to guide and locate wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


after the twisted pairs of cable


100


have been twisted or untwisted to place the twisted pairs in respective grooves


708




a


-


708




h


. Movable body


704


includes movable surfaces


710


,


711


which can be detached and separated from the surface of movable body


704


to inhibit the movement of the wires and to create a gap between movable body


704


and movable surfaces


710


,


711


. Each of movable surfaces


710


,


711


moves independently along the direction indicated by arrow


712


to hold wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


when they are located on grooves


780




a


-


780




h


inhibiting the movement of the wires. After the unreeling, cutting and removing operation of step


805


, cable


100


is placed on pallet


700


.





FIG. 30

shows stripped cable


100


mounted on pallet


700


. The cut edge of jacket


111


is flush with the edge of main body


702


of pallet


700


. Pallet


700


is now ready to be transferred to station


620


.

FIGS. 31 and 32

illustrate elements of station


620


, which includes clamp


720


, horizontal pin


722


and presser


728


.




At step


810


of

FIG. 28

, cable


100


is clamped on main body


702


of pallet


700


at station


620


, as shown in FIG.


31


. Main body


702


is configured to hold the clamped cable so that the cable ends on main body


702


can rotate.




At step


815


of

FIG. 28

, horizontal pin


722


is inserted into cable


100


and applies pressure to twisted pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


of cable


100


to separate the twisted pairs against the surface of main body


702


as shown in FIG.


31


.





FIG. 31

shows the clamping and pin inserting operations of steps


810


and


815


. Clamp


720


is in contact with main body


702


. Horizontal pin


722


can be moved along the direction indicated by arrow


724


and can be rotated along the direction indicated by arrow


726


. The inserted end of pin


722


is bullet shaped, hemispherical or rounded to ensure proper fan-out. The depth of insertion of pin


722


into cable


100


must be sufficient to exceed the elastic limit of the wires, so that they retain a fanned-out configuration after pin


722


is removed.





FIG. 32

shows the pressing operation of step


815


. Presser


728


presses twisted pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


of cable


100


at the edge of jacket


111


to further separate the twisted pairs. Small space


729


is provided at the bottom center of presser


728


for facilitating further movement of the twisted pairs. Space


729


is blocked by pushing down blocker


727


after the twisted pairs have been fixed, in order to inhibit further movement of the twisted pairs. Clamp


720


and presser


728


function to hold and press cable


100


.




Pallet


700


is next transferred to station


630


, shown in

FIGS. 33-35

, which includes machine vision system


730


having lens


732


, collet style chuck


735


and vertical pin


740


. Only the pertinent portion of machine vision system


730


is shown in

FIG. 33-35

.




At step


820


of

FIG. 28

, machine vision system


730


at station


630


detects and identifies the color and position of jackets


122


,


132


,


142


,


152


,


162


,


172


,


182


,


192


of twisted pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


of cable


100


as prepared at step


815


. Collet style chuck


735


, cooperating with machine vision system


730


, holds and relocates each of twisted pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


of cable


100


to place a particular pair at a predetermined position, e.g., blue/light blue pair at left.





FIG. 33

shows the detecting and positioning operations of step


820


. Collet style chuck


735


grasps one of twisted pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


and relocates the selected twisted pair to be in a predetermined color sequence according to information from machine vision system


730


. Collet style chuck


735


can move freely along the directions indicated by arrow


736


. Machine vision system


730


identifies the colors of twisted pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


and gives collet style chuck


735


information regarding the predetermined color sequence of the twisted pairs. A suitable system for use as machine vision system


730


is a Cognex System from Cognex Corporation in Natick, Mass. Alternatively, the F-30 system available from Omron Electronics, Schaumburg, Ill. may be used.




At step


825


of

FIG. 28

, the sequenced twisted wire pairs are clamped on pallet


700


to avoid further unintended relocation.





FIG. 34

shows the clamping operation of step


825


. After relocation of twisted pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


by collet style chuck


735


, space


729


of presser


728


is blocked by blocker


727


to clamp the sequence of the twisted pairs, thereby prohibiting the twisted pairs from further movement. At the conclusion of step


825


, twisted pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


are located in a predetermined color sequence and in grooves


950




a


-


950




d


shown in FIG.


29


.




At step


830


of

FIG. 28

, movable body


704


is lifted up to align with the surface of main body


702


.

FIG. 35

shows the sequencing operation of step


830


. Machine vision system


730


identifies each of twisted pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


of cable


100


and collet style chuck


735


twists/untwists each of the twisted pairs to be in a predetermined color sequence of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


. Vertical pin


740


is inserted to establish a predetermined space between the wires of the twisted pairs while collet style chuck


735


holds the twisted pairs. At the conclusion of step


830


, wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


are in grooves


708




a


-


708




h


of pallet


700


in a predetermined color sequence.





FIG. 36

shows wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


sequenced and placed in grooves


708




a


-


708




h


of pallet


700


. The ends of the twisted pairs remain twisted.




As shown in

FIGS. 37A and 37B

, after the wires are placed in grooves


708




a


-


708




h


in the predetermined color sequence, movable surfaces


710


,


711


are detached from the side of movable body


704


in the direction indicated by arrow


713


. Detaching movable surfaces


710


,


711


creates gap


741


between movable body


704


and movable surfaces


710


,


711


. As shown in

FIG. 37B

, each of movable surfaces


710


,


711


slides in opposite directions indicated by arrow


712


to secure wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


. Clamp


720


and presser


728


are then released.





FIG. 38

shows the sequenced wires on pallet


700


after the sequencing process described above.




Pallet


700


is next transferred to station


640


which includes manipulators


750


,


760


, a feeder (not shown) and a cutter (not shown). The feeder may be a bowl, tape or flexible feeder. Manipulator


750


serves to transfer parts from the feeder.




At step


835


of

FIG. 28

, first housing member


202


of two piece type connector


200


is assembled with wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


at station


640


.





FIG. 39

shows manipulator


750


loaded with first housing member


202


, and pallet


700


loaded with sequenced wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


. Manipulator


750


is aligned so that gaps


220




a


-


220




h


of first housing member


202


are positioned on top of gap


741


of pallet


700


. Manipulator


750


then moves down to the top of pallet


700


along the direction indicated by arrow


752


.





FIG. 40

shows manipulator


750


holding first housing member


202


of two piece type connector


200


mated to pallet


700


holding sequenced wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


. First housing member


202


is seen to be within manipulator


750


. Manipulator


750


presses member


202


with a predetermined force to insert each of the sequenced wires of cable


100


into gaps


220




a


-


220




h


and IDC grooves


217




a


-


217




h


of first housing member


200


. A cutter (not shown) is then introduced through the bottom of gap


741


of pallet


700


. The cutter cuts the portions of the sequenced wires which extend beyond IDC grooves


217




a


-


217




h


of first housing member


200


. Manipulator


750


is then lifted from main body


702


of pallet


700


while holding first housing member


202


assembled with the wires of cable


100


.




At step


840


of

FIG. 28

, manipulator


760


feeds second housing member


204


, and at station


640


, second housing member


202


is assembled with first housing member


202


.





FIG. 41

shows manipulator


760


loaded with second housing member


204


of two piece type connector


200


. Second housing member


204


is also shown in FIG.


6


. In

FIG. 41

, IDC


246




d


is not shown so that upstanding post


238


d can be clearly shown. Manipulator


760


is positioned beneath manipulator


750


. Manipulators


750


,


760


are aligned so that each of IDCs


246




a


-


246




h


of second housing member


204


matches with IDC grooves


217




a


-


217




h


of first housing member


202


, respectively.




Manipulator


750


moves down to the top of manipulator


760


along the direction indicated by arrow


762


. Manipulator


750


presses member


202


with a predetermined force to assure that each of IDCs


246




a


-


246




h


is inserted into IDC grooves


217




a


-


217




h


of first housing member


200


until the wires of cable


100


respectively rest on the tops of upstanding posts


238




a


-


238




h


, completing the automatic assembly of two piece type connector


200


.




Assembled two piece type connector


200


is now ready to be transferred to station


650


, where the assembled connector


200


is tested and packed for shipping.




Station


650


includes testing equipment (not shown). After testing, and if results are good, the assembled cords are packed for shipment. Station


650


also has equipment for rejecting assembled connectors having inadequate test results. The rejected cables having connectors may be sent back to the appropriate station to correct defects, may be discarded, or may be sold as lower performance level merchandise.




Station


660


includes a central control station (not shown) for automatically controlling the activity of stations


610


-


660


. Alternatively, each of stations


610


,


620


,


630


,


640


,


650


has its own independent control system.




With the present automated assembly technique, most of the subsystems are identical for assembly of 110 connectors, D8GS connectors, RJ45 connectors and RJ11 connectors. Generally, the type of the connectors determines the variation in the production lines. Tooling changes in the wire and manipulator housings are needed for different types of connectors or newly designed connector assemblies





FIG. 42

shows a flow chart of an assembly procedure for another embodiment. Steps


805


,


810


,


815


in

FIG. 28

correspond to steps


905


,


910


,


915


in FIG.


42


. In

FIG. 42

, positioning twisted wire pair step


820


, clamping the positioned twisted pairs step


825


, and positioning wires step


830


of

FIG. 28

are combined together as sequencing step


920


.




At step


920


of

FIG. 42

, pin


722


shown in

FIG. 31

is inserted horizontally into twisted wire pairs


120


-


130


,


140


-


150


,


160


-


170


,


180


-


190


to fan out the wire pairs and presser


728


presses the separated twisted wire pairs against the surface of pallet


700


. Instead of sequencing each twisted pairs first as in the process of

FIG. 28

, machine vision system


730


identifies each of wires


120


,


130


,


140


,


150


,


160


,


170


,


180


,


190


of cable


100


. Collet style chuck


735


grasps each of the wires and relocates the selected wire to a predetermined position. The sequenced wires are clamped on the carrier to avoid further unintended relocation.




In one embodiment, machines are operated by centralized computer control. In another embodiment, individual machine control programs are generated in each machine and each machine is operated independently. This method of operation is particularly useful where assembly lines or portions of assembly lines are comprised of machines placed side by side in a row. The assembling process takes place by transporting a carrier from machine to machine.




Although illustrative embodiments of the present invention, and various modifications thereof, have been described in detail herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to these precise embodiments and the described modifications, and that various changes and further modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.



Claims
  • 1. A method of automatically assembling a cable having at least two twisted wire pairs surrounded by a common insulating jacket, each wire of the twisted wire pairs having a jacket with a respectively different color, comprising the steps of;(a) removing a section of the common insulating jacket to expose the ends of the at least two twisted wire pairs; (b) automatically inserting a pin into the exposed ends of the at least two twisted wire pairs and rotating the pin to separate the twisted wire pairs; (c) automatically detecting the colors of the jackets of the twisted wire pairs; and (d) automatically positioning the wires of the twisted wire pairs in a predetermined sequence based on the colors of the jackets.
  • 2. The method of claim 1, further comprising mounting the cable on a pallet for transporting the cable between stations of an automatic assembly line.
  • 3. The method of claim 2, wherein the pallet has a movable part and further comprising manipulating the twisted wire pairs using the movable part.
  • 4. The method of claim 3, wherein the movable part has a plurality of grooves and further comprising placing the twisted wire pairs in the plurality of grooves.
  • 5. The method of claim 3, wherein the movable part has a plurality of movable surfaces and further comprising moving the plurality of movable surfaces to inhibit movement of the wires.
  • 6. The method of claim 3, further comprising adjusting the height of the movable part for improving ease of access to the twisted wire pairs.
  • 7. The method of claim 1, wherein the automatically detecting is performed by a machine vision system.
  • 8. The method of claim 7, further comprising;automatically applying pressure to the twisted wire pairs so that the twisted wire pairs fan out relative to each other.
  • 9. The method of claim 1, further comprising automatically manipulating each of the twisted wire pairs so that the wires of the twisted pairs can be separately positioned.
  • 10. The method of claim 1, further comprising automatically using pins to establish spacing between the wires of the twisted pairs.
  • 11. The method of claim 1, further comprising automatically attaching a connector to the automatically positioned twisted wire pairs.
  • 12. The method of claim 11, wherein the connector is one of a 110 connector, a D8GS connector, an RJ45 connector and an RJ11 connector.
  • 13. The method of claim 11, further comprising automatically trimming ends of the twisted wire pairs located inside the connector.
  • 14. The method of claim 11, wherein the automatically attaching includes automatically fitting a first housing to the automatically positioned twisted wire pairs.
  • 15. The method of claim 11, wherein the automatically attaching includes automatically assembling connector housings.
  • 16. The method of claim 15, wherein the automatically assembling includes automatically pressing the connector housings together.
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Entry
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