Wire connecting block

A wire connecting block includes a pair of mating connectors for effecting electrical cross-connections between a first set of conductors and a second set of conductors. The first connector indexes the first conductors and holds them in alignment for engagement with a plurality of insulation-penetrating slotted beam contacts carried by the second connector. An integral skirt, along the bottom edge of the second connector, covers exposed ends of the first conductors to maintain electrical isolation therebetween. Opposite ends of the slotted beam contacts, exposed along a top edge of the second connector engage the second set of conductors for cross-connection to the first set of conductors.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to improved devices for making electrical 
cross-connections between two sets of conductors and, in particular, to 
improved devices which increase the amount of electrical isolation between 
adjacent conductors in the cross-connected sets of conductors. 
2. Description of the Prior Art 
Wire connecting blocks of the type disclosed in B. C. Ellis, Jr. U.S. Pat. 
No. 3,611,264, issued Oct. 5, 1971, include an indexing strip and a 
connecting block, the latter of which carries a plurality of slotted beam 
contacts. The indexing strip has a plurality of uniform height, 
spaced-apart teeth along its length. These teeth aid in indexing a first 
set of conductors. A corresponding plurality of uniform height, 
spaced-apart teeth carried by the connecting block serve to index a second 
set of conductors to be cross-connected through the slotted beam contacts 
to the first set of conductors. 
A number of improvements to the basic Ellis, Jr. connecting block are 
disclosed in B. C. Ellis, Jr. et al U.S. Pat. No. 3,798,587, issued Mar. 
19, 1974. In the improved version the spaced-apart teeth in both the 
indexing strip and the connecting block are staggered in height to 
facilitate indexing each set of conductors. The Ellis, Jr. et al 
connecting block is a two-piece structure the parts of which are secured 
together following insertion of the slotted beam contacts. While this 
connecting block arrangement has proved to be satisfactory in some 
applications, we have found that when the connecting block is placed over 
the indexing strip in cold temperatures certain stresses are applied to 
the bond between the two connector parts. These stresses often rupture the 
bond causing failure of the entire unit. 
In other applications, such as outdoor environments, moisture collects 
across the exposed conductor ends. This moisture oftentimes results in 
short circuits between some of the conductors. In an attempt to alleviate 
this problem, an insulative, greaselike compound is placed in the 
connector cavity. While this greaselike compound aids in the reduction of 
electrical short circuits, unfortunately it further increases the 
mechanical stresses applied to the joint between the two connector parts 
as the connector is brought into engagement with the indexing strip. The 
present application is directed to further improvements in the connecting 
block structures disclosed in the aforementioned patents. 
It is one object of the present invention to alleviate the mechanical 
stresses produced during engagement of the connecting block with the 
indexing strip. 
Another object is to encase the exposed ends of the conductors thereby 
electrically insulating them from one another. 
A further object of the present invention is to improve the locking 
arrangement between the connector body and the indexing strip. 
Yet another object is to improve the indexing strip in order to facilitate 
engagement of the connecting block therewith. 
Still a further object is to provide a conductor holding arrangement in the 
indexing strip to hold indexed conductors in place prior to engagement 
with the connecting block. 
An even further object of the present invention is to increase the 
electrical isolation among a second set of conductors when brought into 
engagement with the connecting block and ultimately the first set of 
conductors. 
Still a further object is to configure the connecting block such that it is 
readily engageable with a test cord. 
SUMMARY OF THE INVENTION 
The foregoing objects as well as other objects of the invention are 
realized in an illustrative embodiment of apparatus for electrically 
interconnecting first conductors with associated second conductors. This 
interconnection apparatus includes first and second mating connectors 
which are made of electrically insulative material. The first connector 
has provision therein for individually receiving and indexing the first 
conductors. Ends of these first conductors are exposed along one side of 
the first connector. The second connector carries a plurality of slotted 
beam contacts which are held in a predetermined spatial relationship so as 
to be engageable with the first and second sets of conductors, 
respectively. A skirt portion integral with the second connector encases 
the exposed ends of the first conductors to electrically isolate them from 
one another. 
Accordingly, it is one feature of the present invention that the second 
connector is configured so as to alleviate mechanical stresses heretofore 
applied to a bond joint. 
Another feature is that the second connector includes provision for 
facilitating alignment of the slotted beam contacts therein. 
Still another feature of the present invention is that the second connector 
has integral therewith a skirt which encases exposed conductor ends of the 
first set of conductors. 
A further feature is that an end of the second connector opposite the end 
having the skirt provides increased electrical isolation among the 
conductors of the second set of conductors. 
Yet another feature is that the first connector includes funnel-shaped 
entry ways on spaced-apart indexing teeth to facilitate alignment of the 
first and second connectors during mating. 
An even further feature of the present invention is that the first 
connector includes an anvil to facilitate wire cutoff. 
Yet a further feature is that the spaced-apart teeth of the first connector 
have opposed depressions in adjacent sidewalls to facilitate capture of 
the first set of conductors as they are indexed. 
Still a further feature of the present invention is that the locking 
arrangement between the first and second connectors is improved through 
the provision of truncated cylindrical projections along sidewalls of the 
spaced-apart teeth on the first connector. These truncated cylindrical 
projections have a thickness at their bottom which is greater than the 
thickness at the top and this variation in thickness ensures a tight 
retention with a plurality of apertures in sidewalls of the second 
connector. 
Still a further feature is that the bottom sidewalls of the second 
connector are scalloped to decrease interference with larger outside 
diameter wires. 
Still another feature of the present invention is that alternate 
spaced-apart teeth of the second connector have barbed tips thereon to 
assist in holding a test cord in connection therewith.

DETAILED DESCRIPTION 
A first mating connector, hereinafter denoted as indexing strip 11 and 
shown in FIGS. 1 through 3, includes a longitudinally extending body 
member 12. Integral with body member 12 and extending generally 
perpendicular to an axis thereof are a plurality of spaced-apart teeth 13. 
Teeth 13 alternate in height to facilitate indexing of a first set of 
conductors 14 shown in FIG. 9. To further facilitate wire indexing, teeth 
13, as shown in FIG. 1, have tapered tip regions 15 on adjacent sidewalls 
16. These tapered tip regions 15 form generally funnel-shaped wire entry 
ways for directing conductors 14 into wire retaining slots 17 formed by 
spaced-apart teeth 13. 
Adjacent sidewalls 16 of spaced-apart teeth 13 have integral therewith a 
pair of opposed depressions 18 for capturing and holding an indexed 
conductor 14 in a wire retaining slot 17. Opposed depressions 18 are 
located at an intermediate point along the height of teeth 13 above wire 
retaining slot 17. 
Extending along a length of body member 12 are outwardly projecting edges 
20 and 21, as shown in FIG. 2. Edges 20 and 21 are at different elevations 
along body member 12 with edge 20 being at a lower elevation than edge 21 
when viewed from tapered tip regions 15 of spaced-apart teeth 13. This 
difference in elevation of edges 20 and 21 enables a polarized engagement 
of indexing strip 11 with a second mating connector 40, as shown in FIG. 
9. Edge 21 has a width nearly twice the width of edge 20. This difference 
in width facilitates cutoff of first conductors 14 by a tool (not shown). 
Also shown in FIG. 2 is a generally funnel-shaped channel 22 which is 
integral with sidewall 16 of spaced-apart teeth 13. A similar channel 22 
is integral with an opposed sidewall 16 of teeth 13. These funnel-shaped 
channels 22 have widths of greater extent at tip regions 15 of teeth 13 to 
facilitate directing slotted beam contacts 30, carried by second mating 
connector 40 and shown in FIG. 4, into engagement with indexed conductors 
14, as shown in FIG. 9. 
Indexing strip 11 is affixed to a support carrier (not shown), similar to 
that illustrated as element 36 in FIG. 2 of U.S. Pat. No. 3,798,587, 
issued to B. C. Ellis, Jr. et al on Mar. 19, 1974, by cylindrical posts 
23. Posts 23 are inserted into apertures in the support carrier and heated 
to produce an expanded head similar to that of a rivet. 
In order to securely couple indexing strip 11 to second mating connector 
40, a plurality of truncated cylindrical projections 24 are integrally 
provided on outer walls of spaced-apart teeth 13. Projections 24, as shown 
in FIGS. 2 and 3, have a greater thickness near an edge opposite tip 
regions 15 of spaced-apart teeth 13. This coupling arrangement will be 
considered in further detail following the description of second mating 
connector 40. 
Once conductors 14 are indexed, cross-connections among these conductors 
and conductors 39 of a second set, as shown in FIG. 9, are effected 
through a plurality of slotted beam contacts 30, shown in FIG. 4. Each of 
contacts 30 includes a central portion 31 which has first and second pairs 
of oppositely directed cantilever beams 32 and 33 extending therefrom. 
Each of the beams in the pairs of beams 32 and 33 are spaced apart from 
one another by elongated generally rectangular apertures 34 and 35, 
respectively. Apertures 34 and 35 extend from central portion 31 to a 
point near a pair of oppositely directed insulation-penetrating edges 36 
and 37, respectively, at the ends of beams 32 and 33. It should be noted 
that beams 33 are of shorter length than beams 32 to increase the force 
provided by edges 37 during engagement with conductor insulation. Also 
included in central portion 31 is a generally oval-shaped aperture 25 used 
in mounting contact 30 in mating connector 40. 
The second mating connector 40, shown in FIG. 4, is comprised of a body 
member 41 which has a plurality of elongated generally rectangular 
cavities 42 therein for slidably engaging slotted beam contacts 30. 
Extending partially along planar inner sidewalls 43 of cavities 42 are 
channel cavities 44. A corresponding plurality of spaced-apart apertures 
45 are included in an outer sidewall 46 of body member 41. Spaced-apart 
apertures 45 are aligned in one-to-one correspondence with rectangular 
cavities 42 and channel cavities 44. 
Once slotted beam contacts 30 are inserted into rectangular cavities 42 and 
aligned such that aperture 25 is beneath a corresponding aperture 26, 
shown in FIG. 6, anchoring member 50 is brought into engagement with body 
member 41. Anchoring member 50, shown in FIG. 5 is comprised of a 
generally flat rectangular member 51. Integral with member 51 and 
extending outwardly therefrom are a plurality of spaced-apart generally 
triangular projections 52. Extending from tops of triangular projections 
52 are projections 53 and 54. Interposed between projections 53 and 54 is 
a notch 55 the width of which is approximately equal to a width of central 
portion 31 between apertures 25 and 34 of contact 30. 
Triangular projections 52, in conjunction with projections 53 and 54 and 
the depth of notch 55, limit the extent of engagement of slotted beam 
contact 30 with rectangular member 51. It should be noted that projection 
53 extends into channel cavities 44. This mounting arrangement for slotted 
beam contacts 30 couples insertion forces produced during engagement of 
second mating connector 40 with indexing strip 11 into projections 53 and 
54. Consequently, the insertion forces tend toward the shearing of 
projections 53 and 54 rather than the splitting of body member 41. 
To ensure proper alignment of anchoring member 50 with body member 41, the 
former includes a projecting lip 56 along a lengthwise edge 57. Outer 
sidewall 46 has a mating groove 48 extending along its length. This lip 
and groove arrangement provides a polarized mating of anchoring member 50 
with body member 41. Once in place these two members are secured to one 
another, for example, by ultrasonic welding. 
As shown most clearly in FIGS. 7 and 9, body member 41 has integral 
therewith and extending outwardly away therefrom a generally L-shaped 
skirt 61. A plurality of scallops 62, as shown in FIG. 4, along the base 
leg of the "L" and along opposite edge 63, engage conductors 14, as shown 
in FIG. 9, and hold them in place between indexing strip 11 and mating 
connector 40. Skirt 61 encases exposed ends 19 of first conductors 41 to 
electrically isolate them from one another. Not only does the insulative 
material of which both indexing strip 11 and mating connector 40 are made 
provide electrical isolation, but skirt 61 in conjunction with sealing 
compound (not shown) shields exposed ends 19 to prevent any accumulation 
of moisture which could cause electrical short circuits. 
After first conductors 14 are individually received and indexed in indexing 
strip 11 and conductor ends 19 are trimmed to the proper length, mating 
connector 40 with the plurality of slotted beam contacts 30 therein is 
brought into engagement with indexing strip 11. Mating connector 40 is 
coupled securely to indexing strip 11 by projections 24 which engage a 
corresponding plurality of circular apertures 49 in sidewall 46 and skirt 
61. Circular apertures 49 are aligned in correspondence with truncated 
cylindrical projections 24 so that apertures 49 surround projections 24 
with the greater thickness inhibiting separation of mating connector 40 
from indexing strip 11 once the two are mated. 
It should be noted that mating connector 40 holds the slotted beam contacts 
30 in a spatial relationship so that an individual contact 30 is 
engageable with an individual conductor 14. Opposite ends of contacts 30 
are now available for engagement with second conductors 39, as shown in 
FIG. 9. 
To facilitate alignment and indexing of second conductors 39, mating 
connector 40, as shown in FIGS. 6 through 8, has a plurality of 
spaced-apart, alternating height teeth 65 integral with body member 41. 
Teeth 65 have a configuration somewhat similar to that of teeth 13 on 
indexing strip 11 insofar as teeth 65 have tapered tip regions 66 forming 
funnel-shaped wire entry ways 67. Near the bottom of wire retaining slots 
68 formed by adjacent sidewalls 69 of teeth 65 there are oppositely 
directed interference projections 71. Projections 71 have a thickness of 
greater extent at a central point therein which is removed from taper tip 
regions 66. Projections 71 facilitate capture and inhibit conductors 39 
from separating from mating connector 40 after being seated in contacts 
30. 
Electrical isolation is provided among exposed ends of conductors 39 by 
extended lateral projections 72 on teeth 65 as shown in FIG. 8. These 
extended projections 72 increase the electrical path length between 
adjacent exposed conductor ends. On outer edges of alternate ones of 
projections 72 are projecting lips 73 for facilitating engagement of a 
test cord (not shown) with mating connector 40. 
In all cases, it is to be understood that the above-described embodiment is 
illustrative of but a small number of many possible specific embodiments 
which can represent applications of the principles of the invention. Thus, 
numerous and various other embodiments can be devised readily in 
accordance with these principles by those skilled in the art without 
departing from the spirit and scope of the invention.