CONNECTOR FOR RIBBON CABLE

Abstract: Connector for ribbon cable (2) comprises a housing (10) having rows of terminals (18) with C-shaped body portions (22) in respective rows of passages (12) of square cross section. Each body portion (22) has a substantially planar first plate (24) which extends to a coplanar slotted plated portion (42) which receives a cable conductor (3). The plate (24) is stamped with opposed lugs (30, 32) which engage opposite walls of the passage (12) for angular orientation which does not depend on formed dimensions of the body portion (22).

Description: -1- CONNECTO FOR RIBBON CABLE The present invention relates to a connector for ribbon cable, and particularly to improved means for aligning terminals in the housing . Ribbon cable provides a convenient means for handling multiple conductors, and is typically manufactured with conductors on .050 inch center! ine spacing in a common jacket of insulation . Accordingly, specialized connectors having insulation displacing terminals with slotted plates on .050 inch centerline spacinc have been developed . Typically , such connectors have two ro s of terminals spaced on .100 inch centers, the slotted plates in each row being offset from the slotted plates in the other row so that each row of terminals terminates alternate conductors in the cable. An early connector of this type, which is sold by AMP Incorporated under the trademark AMP-LATCH , is disclosed in U . S. Patent No. 3 ,820,055. U . S. Patent No. 4, 367,004 discloses an electrical connector of the type comprising an insulative housing having a mating end , a cable receiving end , and a plurality of terminal passages extending therebetween , the passages being of generally square cross section. The connector further comprises a plurality of stamped and formed terminals received in respective passages , each terminal having a body portion of generally C-shaped cross-section , the body portion comprising a substantially planar first plate extending to a coplanar slotted plate portion . Terminals as described above generally depend on contact between the three plates of the C-shaped body portion and respective adjacent walls of the passage to angularly position the terminals in the housing . A detent may be stamped in one or more walls to provide an interference fit for retention . For such small terminals (about .070 inch square in the body portion) , it is extremely difficult to control the formed dimensions relative to the terminal size. Since stamped dimensions are relatively easy to control , an oversized formed dimension means that another dimension formed within the same stamped dimension will be -2- undersized . Most notably , a plate of oversized width means that one or two of the other plates will be undersized. This in turn affects the angular orientation of the terminals in respective passages , and likewise the centerline spacing of the slotted plate portions. Considering also the tolerances in spacing of conductors in the ribbon cable, damage or even severing of one or more such conductors is possible. According to the invention , the first plate of the body portion of each terminal is stamped with a pair of opposed lugs which engage opposite walls of the passage. The other two plates of the body portion do not contact adjacent walls of the passage and thus do not affect angular orientation of the terminals. Since it is possible to control the stamped dimension between lugs with some precision, and further possible with passage lead-ins to control the engagement points of respective lugs, it is possible to control the angular position of terminals in respective passages. Since each slotted plate is stamped in the same plane as the first plate, it is likewise possible to control the centerline spacing of the slots . The likelihood of damage to conductors in the ribbon cable is thus considerably reduced. An additional advantage is achieved where the mating end of the terminal comprises cantilever arms extending from parallel plates of the body portion. Precise angular orientation of the terminal assures that parallel surfaces of the mating ends of the arms will contact opposite sides , rather than edges , of a mating pin. An embodiment of the invention will now be described by way of example with reference to the accompanying drawings , in which: FIGURE 1 is an exploded perspective of a sectioned connector; FIGURE 2 is a perspective of the connector, ribbon cable, and cover. FIGURE 3 is an end section of the connector. -3- FICURE 4 is a partial side section taken along line 4-4 of Figure 3; FIGURE 5 is a partial plan section taken along line 5-5 of Figure 3; FIGURE 6 is a perspective of a prior art terminal ; FIGURE 7 is a partial plan section similar to Figure 5 with the prior art terminal . Referring to Figure 1 , the inventive connector comprises a dielectric housing 10 having a cable receiving end 14, a mating end 16, and a plurality of terminal receiving passages 12 extending therebetween . Each passage 12 is of generally square cross section and has a pair of ribs 20 on opposite walls extending from proximate the mating end 16 toward the cable receiving end 14. A pair of lead-ins 15 in opposed walls of each passage 12 at cable receiving end 14 serve to position terminals 18 received therein , as will be described. Each terminal 18 is stamped and formed from conventional metal strip stock and comprises a body portion 22 of generally C-shaped cross-section having a first plate 24, a parallel third plate 28 , and a second plate 26 (in two sections) extending substantially normally therebetween. The first and third plates 24, 28 have respective cantilever arms 34, 36 extending therefrom to contact surfaces 38 , 40 for engaging a pin . The first plate 24 is stamped with a pair of opposed lugs 30 , 32 which are received in passage lead-ins 15 to align the terminal 18 in passage 12. The first plate 24 further extends to a coplanar slotted plate 42; the slot 48 therein is offset .025 inch from the centerline of plate 24. FIGURE 2 shows the assembled connector , with terminals 18 loaded in two rows of respective passages 12 of housing 10, the slotted plates 42 extending beyond cable receiving end 14. The slots 18 are spaced at .100 inch in each row and are offset .050 inch from slots 48 in the other row in order to terminate conductors 3 on .050 inch spacing in cable 2. The conductors 3 are aligned relative to housing 10 by flutes 6 in cover 4 , the -4- slotted plates 42 being received in apertures 5 to latch the cover 4 to the housing 10. In order for terminals 18 to engage conductors 3 without damage, it is thus important that centerline spacing of slots 48 be closely maintained. Note that the passages 12 in each row are directly opposite respective passages in the adjacent row, the offset being achieved by the offset slotted plates 42 and opposite orientation of terminals between rows. The terminals 18 may be installed in the center row of passages in either of two orientations to yield three possible combinations of two rows of terminals to connect with any two of three rows of pins (see also Figure 3) . Figure 3 shows how terminals 18 are axially positioned in passages 12. Each rib 20 serves to prestress the cantilever .-ms 34 , 36, the contact surfaces 38 , 40 bearing against opposite sides of the rib. The rib 20 also serves as a stop to limit insertion depth of the terminal 18 and further serves to withstand the forces imposed during termination of the ribbon cable. Lead-ins 15 receive lugs 30, 32 and serve to position plate 24 flushly against the adjacent wall of passage 12. Figure 4 shows lugs 30, 32 engaged in opposite walls of passage 12. This is an interference fit in the plastic which not only maintains proper angular orientation of the terminal but retains it against withdrawal . Figure 5 is a section view taken through plates 24, 28 between the top and bottom sections of plate 26, showing the engagement of lugs 30, 32 in the housing 10. Clearance between plates 26, 28 and adjacent walls of passage 12 allows for any dimensional variations in forming plates 26 , 28. Figure 6 depicts a terminal 54 according to the teaching of the prior art, which terminal comprises a body portion 54 having first, second and third plates 56 , 58 , 60, respectively , and a slotted plate 72 extending from first plate 58 coplanar therewith . Cantilever arms 64, 68 extend from respective plates 58 , 62 and have contact portions 68 , 70. -5- Figure 7 depicts the prior art terminals 54 loaded in a housing and illustrates the alignment problem. Since the terminals 54 are received in respective passages in an interference fit between first plate 58, dimple 88 on second plate 60, third plate 62 , and adjacent walls of the passage, any dimensional variations in the width of the plates translates into terminal orientation. The terminals may thus end up skewed , adversely affecting the centerline spacing of slots 78. This skewing is exaggerated for purposes of illustration. The foregoing \s exemplary and not intended to limit the scope of the claims v nich follow.

Claims: -6- CLAIMS 1 . An electrical connector of the type comprising an insulative housing 10 having a mating end 16, a cable receiving end 14, and a plurality of terminal passages 12 extending therebetween, said passages 12 being of generally square cross section , said connector further comprising a plurality of elongate stamped and formed terminals 18 received in respective passages 12, each terminal 18 having a body portion 22 of generally C-shaped cross section , said body portion 22 comprising a substantially planar first plate 24 extending to a coplanar slotted plate portion 42, characterized in that said first plate 24 is stamped with a pair of opposed lugs 30 , 32 which engage opposite walls of said passage 12. 2. An electrical connector as in claim 1 characterized in that each passage 12 has a pair of lead-ins 15 at said cable receiving end 14 for respective said lugs 30 , 32. 3. An electrical connector as in claim 1 characterized in that said first plate 24 of said body portion 22 is received substantially flushly against one wall of said passage 12. 4. An electrical connector as in claim 1 characterized in that each said body portion 22 further comprises a third plate 28 substantially parallel to the first plate 24, said first 24 and third plates 28 having respective cantilever arms 34, 36 extending therefrom to form a mating portion of said terminal , said first 24 and third plates 28 being connected by a second plate 26 extending substantially normally therebetween . 5. An electrical connector as in claim 4 characterized in that each said passage 12 has an elongate rib 20 on one wall thereof, said rib 20 extending from proximate said mating end 16 toward said cable receiving end 14 and forming a stop abutted by said second plate 26 of said terminal 18 to axial ly position said terminal 18 , said cantilever arms 34, 36 being loaded against opposite sides of said rib 20.

Inventors: GROFT JAMES LEON, GROFT, JAMES, LEON
Applicants: AMP INC, AMP INCORPORATED
Application year: 1985
Main classification: H01R13
IPC codes: H01R4, H01R13