US3753216A

US3753216A - High voltage terminal strip

Info

Publication number: US3753216A
Application number: US00189420A
Authority: US
Inventors: E Johnson; D Crabb
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1971-10-14
Filing date: 1971-10-14
Publication date: 1973-08-14
Anticipated expiration: 1990-08-14

Abstract

A terminal strip to provide for varying numbers and combinations of connections between input conductors and output conductors is disclosed. The strip is built up of any desired number of insulating block elements, each of identical structure, all mounted on a channel shaped track between end stops. The block elements have interlocking means, and they define plural cavities with sets of contact terminals inside the cavities to which the conductors are terminated in desired patterns. Barrier wall sections subdivide the cavities and separate sets of terminals. High voltage surge conditions can be successfully withstood due to cavity spacings, post spacings, presence of barrier walls, and use of insulating material for all elements except the contact terminals. Access cover means and cavity identifying marker means are also provided.

Description

United States Patent [191 Johnson et al.

[ HIGH VOLTAGE TERMINAL STRIP [75] lnventors: Erlon Fitch Johnson; Donald Eugene Crabb, both of Elizabethtown, Pa.

[73] Assignee: AMP Incorporated, Harrisburg, Pa. [22] Filed: Oct. 14, 1971 [21] Appl. No.: 189,420

[52] US. Cl. 339/198 GA, 339/218 R, 339/242 [51] Int. Cl H011 9/00 [58] Field of Search 339/198 R, 198 C, 339/198 E, 198 G, 198 GA, 198 11,198 J, 198 K, 198 S, 198 P, 221, 218, 206, 207, 208, 209,

[ Aug. 14, 1973 Primary Examiner-Marvin A. Champion Assistant Examiner-Robert A. l-iafer Attorney-William J. Keating et a].

[ 5 7 ABSTRACT A terminal strip to provide for varying numbers and combinations of connections between input conductors and output conductors is disclosed. The strip is built up of any desired number of insulating block elements, each of identical structure, all mounted on a channel shaped track between end stops. The block elements have interlocking means, and they define plural cavities with sets of contact terminals inside the cavities to which the conductors are terminated in desired patterns. Barrier wall sections subdivide the cavities and separate sets of terminals. High voltage surge conditions can be successfully withstood due to cavity spacings, post spacings, presence of barrier walls, and use of insulating material for all elements except the contact terminals. Access cover means and cavity identifying marker means are also provided.

6 Claims, 5 Drawing Figures Patented Aug. 14, 1973 3,753,216

2 Sheets-Sheet 1 1 HIGH VOLTAGE TERMINAL STRIP BACKGROUND OF THE INVENTION The present invention relates in general to electrical terminal blocks or strips which are adapted to make any desired number and combination of electrical interconnections among a plurality of conductors. The terminal strip of the invention is of the modular type construction, in that it is built up of a plurality of identical terminal block sections. As will be seen, the terminal strip includes special provisions for withstanding very high voltages which under certain conditions might be imposed upon the individual conductors or leads.

The terminal strip of the invention will serve as a flexible and versatile interconnection system. For example, in a junction box for making multiple connections in telephone equipment networks, or among components in data processing systems, or the like, it will provide interconnections for plural. sources to plural loads via individual conductors or via groups of plural conductors.

SUMMARY OF THE INVENTION The high voltage terminal strip described herein is composed of a plurality of insulator housing blocks of identical construction which are mounted on a track member and held together thereon in a stack. The housing blocks are each, in essence, a flat plate or main wall with a pair of crossed dividing walls extending outward therefrom. A plurality of cavities are formed, one between each pair of adjacent main walls of the set, and conductors to be interconnected extend into the cavities from the outside. The aforesaid dividing walls subdivide each cavity into four chambers of equal size. Two pairs of metal contact terminals are mounted in one dividing wall, with the other dividing wall separating the pairs of terminals. The terminals are force fitted into small apertures in the wall in which they are mounted. The walls have notches and cooperating tabs fitted into notches of adjacent sections to interlock them into a unitary strip. The conductors are terminated to opposite ends of the terminals in any selected pattern. More than one conductor can be terminated to one end of each terminal if necessary.

It is an object of the invention to provide a terminal strip assembly serving to make interconnections between plural electrical conductors in any desired pattern, and in a structure which affords protection against high voltage surges on said conductors.

It is another object to provide such a terminal assembly made up of a small number of different component parts, all of insulating material for high voltage protec tion, and so as to be rugged, reliable, flexible in use and service repair, and at the same time inexpensive to manufacture.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view, partly in section, of a group of terminal blocks assembled on a track and making up the terminal strip of the invention;

FIG. 2 is a perspective view of one of a plurality of cover members employed in the terminal strip assemy;

FIG. 3 is a cross-sectional view of one of the identical terminal blocks mounted on the track and with covers in place at top and bottom thereof, looking in the direction of arrows 3-3;

FIG. 4 is an elevational view of the back side of the terminal block of FIG. 3; and

FIG. 5 is a partial cross-section showing an alternative construction for mounting a terminal block in the track.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 3, the terminal strip 10 of the invention is made up of a plurality of terminal block housings ll of insulating material stacked together on a track 12 as shown. Each housing 11 comprises a flat plate-like member 13 which forms a planar back wall of the housing oriented perpendicular to the track 12 when in position in the strip. A perpendicular pair of dividing walls or partitions l4 and 15 extend forward from back wall 13 along center lines as shown and serve to divide the volume between each adjacent pair of wall members 13 into four smaller cavities of equal size. The partitioning wall 15 in each of the plural housings 11 supports two sets of elecrical contact posts 16 which extend through apertures in the wall 15. It is seen that there are two such terminals 16 in each set and that the two sets of terminals are separated by the other wall 14.

With this arrangement a pair of insulated electrical conductors, such as leads 20 in FIG. 1, which are required to be interconnected may be terminated to opposite ends of one of the contact terminals 16. The termination of the conductors to the terminals may be effected by any standard technique, such as by soldering of the leads to the terminals, by conventional wrap-type connections or clip-type connections. The two posts 16 of each set are themselves interconnected by a conductive bridging element 17 which may simply be the carrier web between adjacent terminals where the latter are fabricated in strip form. With the arrangement shown, a maximum of four lead connections can be accommodated at each position, as shown at the left side of the first terminal block housing in FIG. 1. The right side of that block shows that one lead (at the top) may interconnect with two leads (at the bottom) if desired. The doubled posts 16 provide the further feature that an extra terminal is available in case of breakage of the originally used terminal, in those cases where double connections at one end are not needed, as at the right side in FIG. 1.

Each housing 11 has

end wall portions

23 and 24 extending outward from back wall 13 along the left and right edges and parallel to

walls

14 and 15.

End walls

23 and 24 terminate short of the upper and lower edges of plate 13, as shown in FIG. 3, leaving space for the electrical leads to enter the respective cavities. A base or footlike wall portion 25 extends from wall 23 and beyond the periphery of member 13. It has a shape complementary to the interior channel of track 12 to mount each terminal block therein.

The

various walls

14, 15, 23, 24 are all of the same height and with plural housings l1 stacked together, their outer edges abut the back side of the adjacent main wall member 13. However, a number of interlocking means are provided to give rigidity to the stackedup housing sections, as follows. Each wall portion 24 (at the right in FIGS. 1 and 3) has a pair of cut-out portions in the form of notches or rectangular grooves 30, and in addition, the wall 24 has two protruding rectangular tabs 31 of complementary shape extending out beyond the opposite side of main wall 13. The tabs 31 of one housing section fit within the notches 30 of the adjacent housing section to intermate the housings. Also, a set of wall sections 32 extend out from the said opposite side of main wall 13 in a position to receive portions of the end of wall therebetween. Finally, the outer ends of wall 14 are shaped so as to have a widened or thicker section, identified as 33 and 34, which are provided with outwardly facing grooves or

channels

35 and 36. The wall 24 contains a similar channel or groove 37 intermediate the notches 30. A plurality of flat elongated strip members of rectangular crosssection, such as members 38 and 39 in FIG. 1, are provided with the assembly. These strips are dimensioned to fit within the

grooves

35, 36, and 37 to align the housing sections 37 and to make the terminal strip assembly more rigid. Another feature is that these strips 38, 39 may have an embossed tape applied thereto having indicia such as numerals or code lettering to identify each section of the strip. This can be for the purpose of identifying the circuits associated with particular signal conductors 20, as suggested by the term Nomenclature shown on marker strip 39 in FIG. 1.

The desired number of housing sections 11 may be inserted into track 12, leads terminated to the contact terminals 16 in desired patterns or combinations, and the identical sections 11 brought together to form the strip by the interlocking means described above. End stop blocks such as at 40 in FIG. 1, one at each end of the strip, tightly clamp the housing sections together via set screws engaging the track as shown at 41.

The terminal strip of the invention has a number of features which allow its use in applications where unwanted surges of high voltage may have to be withstood without any damage to the interconnection system being provided. Thus, for instance, in making interconnections with this terminal strip in a telephone system junction box, the conductors normally carry only low voltage level signal currents. However, under certain fault conditions in the equipment being interconnected, surges of high voltage (possibly as high as 20 KV or above) may be temporarily impressed on the conductors. Similar problems may occur in data processors or other communications equipment. The disclosed terminal strip assembly can be used in these circumstances of possible high voltage surge without danger of damage either to itself or to components connected thereto. Breakdown of insulation would occur in prior art terminal strips under such conditions.

In the first place, each housing 11 is of a dielectric material and has a cavity depth large enough to permit the application of up to 27 KV DC, under tests actually performed, with no voltage applied to the contact terminals of the adjacent housing section. That is to say, the sets of terminals are spaced apart axially (i. e., along the length axis of track 12) so that, considering also the isolation provided by the insulating barrier wall 13, the assembly can withstand high voltage above 20 KV between adjacent cavities. Also, within each housing section the two sets of contact terminals are separated by the barrier formed by wall 14, and are spaced so as to permit a voltage difference of up to 1,500 volts DC between pairs of posts in one section. Another important aspect for withstanding high voltages is that no metallic parts are used in the assembly except for the contact terminals 16, which may be of tin plated hard brass. All other elements described above are of insulating material and formed by injection molding, and extrusion molding in the case of track 12 and strips 38, 39. The insulating material used may be any suitable insulating plastic such as diallyl phthalate or a relatively firm nylon such Ultramid.

The cavities within the various sections 11 require cover members at the top and bottom as seen in FIGS. 1 and 3. A particularly suitable cover member is shown in perspective in FIG. 2. It is in the form of a generally flat rectangular bar with a pair of grooves or

channels

51 and 52 formed in the outer surface thereof, similar to the previously described grooves. Bar 50 has serrated ends at 53 to provide a surface for good finger gripping as will be described. The bar 50 is dimensioned in length and width to fit in and close the ends of the cavities within housing sections 11, as seen in FIG. 3, one cover 50 also being shown in place in FIG. 1 on the rearmost housing section. The cover bars are snapped in place between adjacent main walls 13 and mounted pivotally at both ends in the following manner. The'bar 50 has four thin legs depending therefrom, two at each end as at 53 in FIG. 2. A disc-like lateral projection 54 extends outward at the end of each leg 53 as shown. Sets of four blind holes 55 are formed in each wall member 13 near the covers thereof and on both sides. The holes 55 are located and sized to pivotally receive the disc projections 54 of legs 53. The covers can be snapped in place one way or rotated 180 since they are symmetrical. Also, access can be had to any cavity to make repairs to the connections either from the top or the bottom, and covers 50 can be pivoted out by hand in the manner shown in FIG. 3, or the cover maypivot from the opposite end from the one shown at the bottom of FIG. 3.

The wall 14 has a pair of openings 70 at opposite ends. This permits the use of a commoning or jumper lead 71 between sets of terminals in one cavity where connection patterns so require. The tracking length up to opening 70 between terminal sets is longer than the straight line separation distance, so the voltage difference of 1,500 volts DC can be held despite these openings in the barrier wall. FIG. 3 also shows clip-type connector member 62 coupling lead wires to terminals 16.

A useful feature is the manner in which two or more of the covers 50 may be ganged together to gain access to a set of cavities without the necessity of operating each cover individually. For this purpose the

grooves

51 and 52 have been provided. A flat strip similar to previously described strips 38, 39 is dimensioned to fit within either

groove

51 or 52. By simply cutting sections of strip 60 to the appropriate lengths to couple or gang desired numbers of covers 50 together, one manual operation of a ganged cover group can open any number of cavities, such as two, six, etc. Also single covers can be left uncoupled by any strip 60 for individual cavity access where desired. Also, a marker or indicia tape or other position indicating means may be applied to the outside of strip 60, the same as in the case of numbering indicia carried on strips 38 and 39.

The invention provides a versatile terminal strip, featuring maximum flexibility for achieving a wide range of connection patterns, an easy access to any contact area internally of the assembly from either end, provisions to give full protection against high voltage surges under circuit faults, paired contact posts to allow a spare if post breakage occurs in a given position, and indicia marking to identify each contact position.

FIG. 5 shows an alternative structure for mounting each housing section 1 l in the track 12. In the embodiment described above, foot 25 was rigid and sections were slipped in at the ends of the tracks. In FIG. 5 the foot of the housing 11 is in the form of two relatively thin plastic legs 81 and 82 of V-shape which have a spring action allowing the housing 11 to be snapped directly into place down over the edges of the track channel. A tool 83 can be used to release a housing 11.

It will, therefore, be appreciated that the aforementioned and other desirable objects have been achieved; however, it should be emphasized that the particular embodiment of the invention, which is shown and described herein, is intended as merely illustrative and not as restrictive of the invention.

What is claimed is:

1. An electrical connecting assembly comprising, in combination, a plurality of identical insulating housing members, means for mechanically interlocking said housing members to form a terminal strip of desired length, a plurality of space-partitioning walls carried by each housing member, a plurality of electrical contact posts mounted in and supported by at least one of said partitioning walls, and means to terminate input conductors and output conductors to selected ones of said contact posts, said assembly further comprising end cover means for said housing members, said cover means having a pair of opposed ends and being detachably and pivotally mounted at both ends thereof to the associated housing members.

2. The electrical connecting assembly of claim 1, and further comprising track means for supporting said housing members in a unitary terminal strip assembly, and end stop means in said track means to clamp said housing members therein.

3. The electrical connecting assembly of claim 1, and further comprising strip means for ganging together predetermined numbers of said end cover means, and indicia carrying identifying means mounted on said housing members.

4. An electrical connecting assembly comprising, in combination, a plurality of identical insulating housing members, means for mechanically interlocking said housing members to form a terminal strip of desired length, each housing member including a single side wall, a plurality of space-partitioning walls carried by each side wall on one side thereof and extending normal thereto, said space partitioning walls including a pair of perpendicular walls connected at substantially the center of each wall, said pair of walls providing four chambers in said housing, said pair of walls being di- 1 mensioned to prevent high voltage arcing between said chambers, a plurality of electrical contact posts mounted in and supported by at least one of said partitioning walls, and means to terminate input conductors and output conductors to selected ones of said contact posts.

5. The electrical connection assembly of claim 4, and further comprising track means for supporting said housing members in a unitary terminal strip assembly, and end stop means in said track means to clamp said housing members therein.

6. An electrical connecting assembly as set forth in claim 5 wherein said space partitioning walls include a pair of perpendicular walls connected at substantially the center of each wall, said pair of walls providing four chambers in said housing, said pair of walls being dimensioned to prevent high voltage arcing between said chambers.

4K k II

Claims

4. An electrical connecting assembly comprising, in combination, a plurality of identical insulating housing members, means for mechanically interlocking said housing members to form a terminal strip of desired length, each housing member including a single side wall, a plurality of space-partitioning walls carried by each side wall on one side thereof and extending normal thereto, said space partitioning walls including a pair of perpendicular walls connected at substantially the center of each wall, said pair of walls providing four chambers in said housing, said pair of walls being dimensioned to prevent high voltage arcing between said chambers, a plurality of electrical contact posts mounted in and supported by at least one of said partitioning walls, and means to terminate input conductors and output conductors to selected ones of said contact posts.