[0001] This invention relates to electrical connectors and more particularly to electrical
connectors for connection with the conductors of ribbon coax cable.
[0002] Terminated ribbon coax cable assemblies are used to electrically connect electronic
circuits of electronic equipment together. These cable assemblies are bent and twisted
thereby subjecting them to stresses which cause the signal and drain conductors of
the ribbon coax cable to move relative to one another which can result in breakage
of one or some of the conductors at the termination sections of the electrical terminals
thereby resulting in open circuits which can be difficult to locate. Moreover, after
a length of ribbon coax cable has been removed from a roll of cable and its ends have
been terminated in electrical connectors, the cable undergoes relaxation whereby more
of the exposed ends of the conductors are exposed and these exposed ends can move
relative to one another which can cause shorting of conductors within the connectors.
[0003] A known connector includes a dielectric body member having conductor-receiving passageways
along which signal and drain conductors of a ribbon coax cable respectively extend
with ends of these conductors being terminated within termination sections of electrical
terminals in the body member. Each conductor-receiving passageway has a recess therein
which receives a respective projection from a cover member that is secured onto the
body member. The projections engage and deform the conductors into the recesses thereby
providing strain relief for the conductors.
[0004] It has been found that the projections have not provided the desired strain relief
on the conductors when the cover members are secured on the body member, because the
projections are small and they vary in size as a result of tolerance factors such
that they are not able to deform the conductors into the recesses to provide the necessary
strain relief thereon. This enables the conductors to therefore move in the conductor-receiving
passageways and places stress on the terminations that can result in failure of some
of the terminations.
[0005] According to the present invention, an electrical connector for flat transmission
cable comprises a body member having terminal-receiving passageways and conductor-receiving
passageways. Continuous recesses are located in the body member between the terminal-receiving
passageways and the conductor-receiving passageways. Electrical terminals are disposed
in the terminal-receiving passageways for terminating electrical conductors of a flat
transmission cable which are disposed in respective conductor-receiving passageways
and extend across the continuous recesses. Cover members are secured onto the body
member and they include projections that extend into respective continuous recesses
engaging the conductors therein thereby providing a strain relief for the conductors.
[0006] According to another aspect of the present invention, the cover members include projections
that are disposed on each side of the conductor-receiving sections of the electrical
terminals to prevent the electrical conductors from disconnecting from the conductor-receiving
sections.
[0007] According to a further aspect of the present invention, the cover members have strain
relief members engaging the cable.
FIGURE 1 is a perspective exploded view of parts of the electrical connector.
FIGURE 2 is a cross-sectional view showing the electrical conductors of the flat transmission
cable terminated to the electrical terminals and the cover members in a partly-closed
position.
FIGURE 3 is a view similar to Figure 2 showing the cover members in a closed position.
FIGURE 4 is an exploded perspective view of part of a body member and a ribbon coax
cable.
FIGURE 5 is a view similar to Figure 4 of an alternative embodiment.
FIGURE 6 is a part cross-sectional view of Figure 5 with the cover members in position.
FIGURE 7 is a perspective view of the terminated electrical connector exploded from
the pins on a printed circuit board intended for connection therewith.
[0008] Figures 1-4 and 7 illustrate a ribbon coax cable connector 10 for terminating signal
conductors 12 and drain conductors 14 of flat transmission or ribbon coax cable 16
which is disclosed in U.S. Patent No. 3,775,552. While ribbon coax cable is being
used, other types of ribbon cable having signal and drain conductors can be used.
Connector 10 comprises a body member 18 and cover members 20, 21 which are molded
from a suitable plastic material.
[0009] Body member 18 includes a series of terminal-receiving passageways 22 on each side
thereof and in which electrical terminals 24 are disposed. Each passageway 22 includes
projections 26, 27 in opposing surfaces which mate with corresponding recesses 28
in a body section 30 of terminals 24 to properly position electrical terminals 24
within passageways 22. Projections 27 are deformed onto body sections 30 to stake
terminals 24 in position in passageways 22. A post-engaging section 32 of electrical
terminal 24 is in alignment with a beveled opening 34 at the front end of body member
18. A conductor-terminating section 36 of terminal 24 is in alignment with a slot
37 in body member 18 and with a respective conductor-receiving passageway 38 in which
conductors 12 or 14 are positioned for electrical termination with conductor-terminating
section 36. Slots 37 and conductor-receiving passageways 38 are beveled at their entrances
to facilitate the positioning of conductors 12, 14 therein. Sloped surfaces 40 are
located on each side of body member 18 along passageways 38. Recesses 42 are disposed
in each side of passageways 38 and they extend to the bottom surfaces of passageways
38. A continuous arcuate recess 43 is located in each side of body member 18 between
slots 37 and passageways- 38 as shown in Figures 1-4. Arcuate recesses 43 extend below
the highest level of slots 37 and sloped surfaces 40. As shown in Figure 4, passageways
38 on one side of body member 18 are offset with respect to the passageways 38 in
the other side of body member 18 so that the inner end of body member 18 has a square
wave configuration.
[0010] Thus, cable 16 is stripped baring only conductors 12, 14 as shown in Figures 1-4
which are then positioned within respective passageways 38, they extend across continuous
recesses 43 into slots 37, conductors 12, 14 are then deformed into respective recesses
43 and then terminated in conductor-terminating sections 36 of electrical terminals
24 in accordance with conventional terminating practices. It is also imperative that
the end of cable 16 be in engagement with the inner end of body member 18 after conductors
12, 14 have been terminated in conductor-terminating sections 36 to prevent migration
of conductors 12, 14 that can short with one another. Thereafter, cover members 20,
21 are secured in place on body member 18.
[0011] Each of cover members 20, 21 has T-shaped sections 48 at the front end thereof which
are disposed in respective passageways 22 and matable within recesses 50 as shown
in Figures 2 and 3. Sections 48 complete the outer ends of beveled openings 34 and
define pivots about which cover members 20, 21 move when being positioned onto body
member 18. Spaced projections 52, -54 extend inwardly from the inside surface of cover
members 20, 21 and they are disposed on each side of respective conductor-terminating
sections 36 when the cover members are secured in position on body member 18 to maintain
conductors 12, 14 in position in conductor-terminating sections. 36. Beveled surfaces
56 of cover members 20, 21 extend along sloped conductors 12, 14 and arcuate projections
58 engage conductors 12, 14 maintaining them into arcuate recesses 43 when cover members
20, 21 are secured in position on body member 18 by rivets 59 thereby defining a strain
relief for conductors 12, 14 to maintain them in position in passageways 38 and recesses
42 and in a terminated position within conductor-terminating sections 36 when stresses
and strain occur as a result of temperature variations or during the handling of cable
16. Projections 52, 54 also maintain conductors 12, 14 within conductor-terminating
sections 36.
[0012] The continuous form of recesses 43 and projections 58 serve to apply pressure on
conductors 12, 14 to maintain them in passageways 38 and terminated in terminating
sections 36 of terminals 24 so that they do not move out of the passageways and short
one another. If conductors 12, 14 do expand or move because of temperature variation
or excess twisting of the cable, part of the conductors 12, 14 can move into recesses
42 to accommodate the movement of the conductors. The continuous form of projections
58 provides a stronger projection for maintaining conductors 12 and 14 in arcuate
recesses 43.
[0013] Wedge-shaped strain relief members 60 which are located on cover members 20, 21 engage
cable 16 when cover members 20, 21 are secured onto body member 18 via rivets 59 thereby
forming a strain relief when stresses and strains are applied to cable 16. Thus, projections
58 engaging conductors 12, 14 in respective- recesses 43 in conjunction with strain
relief members 60. engaging cable 16 function together to maintain conductors 12,
14 within conductor-receiving passageways 38 therefore controlling conductor migration
and preventing stresses on the terminations of conductors 12, 14 in conductor-terminating
sections 36. Connector 10 is inserted onto posts 70 positioned on printed circuit
board 72 or removed therefrom as shown in Figure 7 or matable electrical connectors
10 are connected together within a housing member (not shown).
[0014] Cover member 20 of connector 10 is provided with projection 62 of which the leading
edge is beveled and is a polarizing member for matable engagement within a recess
of a housing member.
[0015] Figures 5 and 6 illustrate an alternative embodiment of body member 18a which is
provided with arcuate recesses 64 as part of conductor-receiving passageways 38a on
one side of body member 18a to receive therein an exposed end of insulation sheath
66 surrounding signal conductors 12 of cable 16 as shown in Figure 6. Passageways
38a on the other side of body member 18a have the same configuration as passageways
38 of body member 18. Migration of conductors 14 in this embodiment will not short
with conductors 12 because of insulation sheath 66 covering conductors 12 and being
disposed within recesses 64.
1. An electrical connector for flat transmission cable (16) including signal conductors
(12) and drain conductors (14), the electrical connector comprises a body member (18)
having terminal-receiving passageways (22) and conductor-receiving passageways (38)
in respective communication therein, electrical terminals (24) disposed within the
terminal-receiving passageways (22) and having conductor-terminating sections (36),
and cover members (20, 21) securable onto the body member (18), characterized in that
said cover members (18) have projection members (58) in alignment with corresponding
continuous recesses (43) in said body member (18) extending across said body member
(18) and between said conductor-receiving passageways (38) and said terminal-receiving
passageways (22), said projection members (58) engaging the respective conductors
(12, 14) in said corresponding recesses (43) when the conductors (12, 14) are disposed
in said conductor-receiving passageways (38) and said cover members (20, 21) are secured
onto said body member (18) thereby providing strain relief for the conductors (12,
14).
2. An electrical connector as set forth in claim 1 characterized in that said cover
members (20, 21) comprise spaced projections (52, 54) extending inwardly from inside
surfaces of said cover members (20, 21) for disposition on each side of said conductor-terminating
sections (36) for maintaining the sections of the conductors (12, 14) terminated in
the conductor-terminating sections (36) therein.
3. An electrical connector as set forth in claim 1 characterized in that cable strain
relief members (60) are provided on inside surfaces of said cover members (20, 21)
for engagement with the cable (16) when said cover members (20, 21) are secured on
said body member (18).
4. An electrical connector as set forth in claim 3 characterized in that said cable
strain relief members (60) comprise wedge-shaped members (60) engageable with the
cable (16).