US3651449A

US3651449A - Resilient terminal blocks

Info

Publication number: US3651449A
Application number: US834329A
Authority: US
Inventors: Frederick W Hall; George Poehlmann
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1969-06-18
Filing date: 1969-06-18
Publication date: 1972-03-21
Anticipated expiration: 1989-03-21

Abstract

A terminal block which in one embodiment comprises a serpentine array of integrally molded plastic clamping members with preformed spaces therebetween. In a second embodiment, the terminal block is molded in two units, with a double row array of spaced clamping members in one unit being interleaved with those in the other unit when assembled. Such terminal blocks as a whole, and the clamping members thereof, in particular, are sufficiently resilient so that the latter by spring action facilitate the selective insertion of terminals therebetween, as well as the selective removal of terminals therefrom without adversely affecting any other terminal connections.

Description

United States Patent Hallet al.

1451 Mar. 21, 1972 [54] RESILIENT TERMINAL BLOCKS [72] Inventors: Frederick W. Hall; George Poehlmnnn,

, both of Indianapolis, Ind.

[73] Assignee: Western Electric Company, Incorporated New York, NY. 1

221 Filed: June18, 1969 211 Appl. No.1 834,329

[52] US. Cl. ..339/244 R, 24/125 R, 174/88 S,

24 /74, 339/246, 339/266 R 51 161.01 ..H0lr 7/08 58 Field 61 Search ..339/198, 241, 242, 244, 246,

339/255, 260, 261, 263, 266, 270, 274; I74/88, I38, l54l56;'248/3l6, 74; 24/81, 125, 135

[56] References Cited UNITED STATES PATENTS 2,543,336 2/1951 Ratchford ..24/81 2,858,5 l6 10/1958 Lindahl et al.. .....339/6'l 3,498,575 3/1970 Downing ..248/7l FOREIGN PATENTS OR APPLICATIONS 335,557 6/1919 Germany .339/270 226,096 8/1946 Switzerland ..339/246 Primary Examiner-Joseph H. McGlynn Attorney-H. J. Winegar, R. P. Miller and A. C. Schwarz, Jr.

[57] ABSTRACT A terminal block which in one embodiment comprises a serpentine array of integrally molded plastic clamping members with pre-formed spaces therebetween. In a second embodiment, the terminal block is molded in two units, with a double row array of spaced clamping members in one unit being interleaved with those in the other unit when assembled. Such terminal blocks as a whole, and the clamping members thereof, in particular, are sufficiently resilient so that the latter by spring action facilitate the selective insertion of terminals therebetween, as well as the selective removal of terminals therefrom without adversely affecting any other tenninal connections.

5 Claims, 6 Drawing Figures PATENTEnmzl I972 SHEET 1 OF 2 \NVENTOQS' F. w. HALL G.POEHL.MANN BY 7 r A TORNEY RESILIENT TERMINAL BLOCKS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to terminal blocks and, in particular, to those employed to provide termination or junction points for terminals and/or lead wires associated with electrical circuitry.

2. Description of the Prior Art Terminal blocks heretofore have generally comprised an array of individual clamping blocks having complementary grooves therein which form wire or terminal supporting apertures. The clamping blocks have generally been made of rigid insulating material, such as plastic, with very little, if any,

resiliency.

Such prior art terminal blocks have necessarily required initially the stacking of a plurality of the discrete clamping blocks so as to form an array, with the clamping blocks thereafter being secured together by suitable fastening members, such as bolts. The assembly of terminal blocks of the type in question obviously is both time consuming and expensive from a manufacturing standpoint.

In addition, whenever it has been desired to insert terminals and/or lead wires between selected adjacent pairs of clamping blocks, or to remove certain terminals therefrom, a problem has often arisen in maintaining either the previously inserted or remaining terminals and/or lead wires in their proper positions until the fasteners have been turned down to force them into compressive engagement with the clamping blocks. In many cases, it has been found necessary to employ special fixtures to'support the loosely held clamping blocks during the securing of terminals to or the removal thereof from the terminal block.

In the interest of brevity, all references to the word terminal or to the plural thereof hereinafter is intended to cover not only formed types of terminals, such as spade tips, but also simple lead wire terminations.

SUMMARY OF THE INVENTION An object of this invention is to provide new and improved terminal blocks which exhibit sufficient resiliency between adjacent terminal clamping portions thereof so that any number of terminals and/or lead wires may be readily inserted in and retained between respective clamping portions by spring-action, or withdrawn therefrom without adversely affecting any other terminal block connections.

It is another object of this invention to provide new and improved terminal blocks molded out of plastic and which are of simple, rugged, reliable and inexpensive construction.

In accordance with the principles of the present invention, the terminal block in one embodiment comprises a serpentine array of integrally molded plastic clamping members with preformed spaces therebetween. The clamping members are formed in two rows with those in one row being respectively offset with respect to those in the other row. This arrangement results in the terminal block as a whole, and the clamping members in particular, being sufficiently resilient so that adjacent ones of the latter, by spring action, will at least temporarily and reliably hold electrical terminals by friction when inserted therebetween.

An axially disposed bore extends through a central area of the terminal block to allow a fastening member to be inserted therethrough both to provide additional compressive force between the clamping members and the terminals inserted therebetween, and to facilitate the permanent securement of the terminal block to a supporting structure.

In a second embodiment, the terminal block comprises two molded plastic units, each unit forming a double row array of clamping members. The clamping members in each row are spaced apart such that those in one unit may be readily and respectively interleaved with those in the other unit during assembly. Contoured shoulders and projections integrally formed in the two units cooperate to insure accurate alignment between the two units of the composite terminal block when assembled.

Advantageously, the second as well as the first resilient terminal block embodiment constructed in accordance with the present invention greatly facilitates the insertion and retention of terminals in or their withdrawal from the terminal block.

In addition, as the subject terminal blocks embodied herein are either molded out of plastic as a one-piece unit, or as two units which are readily interleaved, not only the assembly of the terminal blocks per se but the making of electrical connections thereto are considerably simpler than is the case with prior terminal blocks formed of separate clamping blocks necessarily interconnected only by means of fastening members. The present terminal block construction also obviates the need of special fixtures to support the fastening members temporarily while electrical terminals are being secured to or removed from the terminal block.

Further, as a result of the terminal blocks being made of plastic material, they are not only immune to most chemicals, as well as with respect to absorbing moisture, but they are conducive to color coding which is often very desirable in applications where a number of different terminal blocks are required which may vary only slightly in either their dimensions or in terminal capacity.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of'a first embodiment of a molded plastic terminal block embodying the principles of the present invention;

FIG. 2 is a front elevational view of the terminal block of FIG. 1, with a number of terminals and leadwires being shown supported between different pairs of integral clamping members thereof for purposes of illustration;

FIG. 3 is a fragmentary, perspective view in detail of one normally interleaved half of a second embodiment of a terminal block embodying the principles of the present invention;

FIG. 4 is a front elevational view of the terminal block in accordance with the second embodiment, with a number of terminals being shown supported between different pairs of clamping members for purposes of illustration;

FIG. 5 is a cross-sectional view of the terminal block taken along the line 5-5 of FIG. 4, and

FIG. 6 is a plan view of one half of the terminal block of FIG. 4.

DETAILED DESCRIPTION With particular reference first to the embodiment depicted in FIGS. 1 and 2, a terminal block 10, molded out of any suitable plastic, if formed into a serpentine array of integral plastic clamping members 11 preferably having pre-formed spaces 16 therebetween. The clamping members 11 are formed in two rows, with those in one row being respectively offset with respect to those in the other row. As thus constructed, the terminal block as a whole, and the clamping members in particular, exhibit considerable resiliency. As such, adjacent clamping members 11, by spring-action, will reliably hold electrical terminals by friction when inserted therebetween, without requiring any fastening members to first be tightened. As previously mentioned, such terminals may not only comprise any one of a number of fabricated types, such as the spade-tip terminals 13a, but also lead wires designated by reference nu meral 13b.

In order to facilitate permanent securement of the terminal block to a supporting base 18, and to provide very reliable compressive engagement of the clamping members 11 against the respectively associated terminals, each clamping member has an aperture 19 formed in a central region thereof. These apertures by being aligned, thus form an axial bore through the terminal block which permits the insertion of a fastening member 21 therethrough.

Securement of the fastening member to the support member 18 may be accomplished either by threads on the end of the fastening member 21 which mutually engage the threads of a tapped hole in the support member 18, or by means of a separately threaded nut engaging the end threads of the fastening member on the bottom side of the support member 18.

Advantageously, as a result of the peculiar serpentine configuration of the terminal block and the resilient nature of the spaced clamping members formed thereby, terminals may be inserted between or removed from a pair of adjacent clamping members without adversely affecting any other terminal connections.

A double row of staggered apertures 23 are formed in the terminal block not only to augment the resilient nature of the terminal block 10, but also to provide a means of reducing the amount of plastic material required therefor. It is to be understood, of course, that the apertures 23 could encompass even a larger area of the terminal block than that disclosed, depending in part on the physical characteristics of the plastic material employed, and could comprise a cross=sectional configuration other than circular, if desired.

As the terminal block is made out of any one ofa number of suitable plastic materials, such as Lexon, nylon, etc., the terminal blocks are not susceptible to moisture or to most chemicals, and are conducive to being color-coded to identify a series of terminal blocks which might vary in only a minor way in terms of overall dimensions, and/or in the separation between adjacent clamping members, as well as in the number of clamping members formed in the unitary array.

In a second embodiment of the invention depicted in FIGS. 3-6, a terminal block (FIG. 4) is formed by two serpentine units 31, a perspective, fragmentary view of one unit being shown in FIG. 3. Each serpentine unit 31 comprises a double row array of clamping members 33, the clamping members in each row being offset a sufficient distance to allow an associated clamping member'from the other serpentine unit 31 to be interposed therebetween. Because of the thin, centrally located webs 36 which interconnect the clamping members in one row with those in the other row of each serpentine unit 31, the adjacent clamping members in each row normally have been found to exhibit sufficient resiliency to allow the insertion of terminals 13 therebetween, even when no pre-formed clamping member spaces have been provided.

It is to be understood, of course, that if one or several juxtaposed terminals of substantial thickness are to be inserted between each adjacent pair of clamping members 33, the latter may be molded so as to provide predetermined spaces therebetween when assembled in interleaved relationship, as

' depicted in FIGS. 4 and 5.

In order to insure that the two interleaved units 31 remain in proper alignment after being assembled, contoured shoulders and mating recesses 37 are formed therein to provide stops. Such of course, could also be contoured or dimpled to provide additionally an interlocking feature if desired.

A centrally located U-shaped opening 38 is formed in each cross-connecting leg portion 36 of each serpentine unit 31 so as to form an axially aligned bore through the assembled terminal block. This bore permits a fastening member (not shown) to be inserted therethrough so as to secure the composite terminal block to a desired support base (not shown). As best seen in FIG. 3, the mutually opposed inner faces of the respective pairs of clamping members 33 are tapered inwardly toward each other so as to facilitate the insertion of terminals therebetween, as is also the case, but to a lesser extent, in the embodiment of FIGS. 1 and 2.

In all other respects, the terminal block embodiment of FIGS. 3-6 functions in the same manner and exhibits the same basic features as the first terminal block embodiment depicted in FIGS. 1 and 2.

What is claimed is:

1. A terminal block of insulating material comprisin a double-row array of clamping members, each c amping member, exclusive of the top and bottom ones, in each row being integrally connected by two short, resilient, intermediate portions of reduced cross section to respectively associated and offsetting clamping members in the other row, said top and bottom clamping members associated with each row being integrally connected at least through one short, intermediate portion of reduced cross section to an associated offsetting clamping member in the other row, successive intermediate portions, by interconnecting a clamping member in one row with an offsetting clamping member in the other row, forming said double-row array of clamping members into a serpentine configuration, with the reduced-cross section of said intermediate portions resulting in the clamping members, and the terminal block as a whole, being sufficiently resilient to permit adjacent pairs of clamping members in each row to be independently separated by spring action so as to allow one or more terminals to be inserted therebetween and frictionally retained or removed therefrom without adversely affecting any other terminal block connections, and each clamping member having an extremity which tapers inwardly toward the mating surface of each adjacent clamping member so as to facilitate the insertion of terminals therebetween.

2. A terminal block in accordance with claim 1 wherein said block is made out of molded plastic, wherein each of said short, intermediate portions of reduced cross section is formed, at least in part, by an aperture formed in and extending laterally through each associated clamping member along the width dimension thereof, and wherein a hole is formed through the thickness dimension of each successive intermediate portion of reduced cross section in alignment so as to form an axial bore extending through said terminal block, said bore permitting a fastening member to be inserted therethrough to thereby provide a means both for securing the terminal block to a support structure, and for placing any terminals secured between adjacent clamping members thereof under permanent compressive force.

3. A terminal block in accordance with claim 1 wherein said block comprises two interleaved, molded plastic units, with each unit formed into a serpentine configuration to produce at least two rows of integral clamping members, the respectively adjacent pairs of clamping members in each row of each unit having sufficient space to accommodate a different clamping member of the other unit.

4. A terminal block in accordance with claim 3 wherein each unit is constructed such that each clamping member associated with a particular row thereof is interconnected through two intermediate leg portions of reduced cross section to two integral clamping members forming a part of another row of said unit, and wherein each intermediate leg portion is formed with an opening therein such that successive leg portions in said first and second units form an axially aligned bore through which a fastening member may be inserted so as to provide a means both for securing the composite terminal block to a desired supporting structure, and for placing said composite terminal block and any terminals secured between adjacent clamping members thereof under permanent compressive force.

5. A terminal block in accordance with claim 4 wherein each of said clamping members of each unit is formed with a plurality of projections and undercut ridges which maintain the two units forming said composite terminal block in aligned interleaved relationship when assembled.

UNITED STATES PATENT OFFiCE CERTIFICATE OF CQRRECTION Patent N0. 0) Dated March 9 F. W. Hall-G. Poehlmann I Inventor-(s) lt is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

olumn 2, line 53, "if" should read --is--. Column 3, line 51;,1

"projections and recesses," should follow "811011" and precede "of course,".

Signed and sealed this 25th day of July 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Comissioner of Patents UNITED STATES PATENT OFFICE CERTIFICATE OF CDRRECTION Patent No. '3 .631 .ILLLQ Dated March 97 S) F. W. Hall-G. Poehlma'nn lnventor( It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

olumn 2, line 53, "if" should read --is--. Column 3, line Sui 1 "projections and recesses," should follow "Such" and precede "of course,".

Signed and sealed this 25th day of July 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents

Claims

1. A terminal block of insulating material comprising: a double-row array of clamping members, each clamping member, exclusive of the top and bottom ones, in each row being integrally connected by two short, resilient, intermediate portions of reduced cross section to respectively associated and offsetting clamping members in the other row, said top and bottom clamping members associated with each row being integrally connected at least through one short, intermediate portion of reduced cross section to an associated offsetting clamping member in the other row, successive intermediate portions, by interconnecting a clamping member in one row with an offsetting clamping member in the other row, forming said double-row array of clamping members into a serpentine configuration, with the reduced cross section of said intermediate portions resulting in the clamping members, and the terminal block as a whole, being sufficiently resilient to permit adjacent pairs of clamping members in each row to be independently separated by spring action so as to allow one or more terminals to be inserted therebetween and frictionally retained or removed therefrom without adversely affecting any other terminal block connections, and each clamping member having an extremity which tapers inwardly toward the mating surface of each adjacent clamping member so as to facilitate the insertion of terminals therebetween.