US2928066A - Electrical terminal block - Google Patents

Description

March 8, 1960 J. GORDON 2,928,066

ELECTRICAL TERMINAL BLOCK Filed NOV. 28, 1956 60 7''Ci072/ Jul Wm United States This invention relates to an improved electrical terminal block and terminal for use in connection with switchboards, control circuits for switching apparatus, and similar electrical circuits, the blocks being of the multiple type.

' Particularly in the electronic and automation equipment field, demand is arising for a terminal block'and terminal of relatively small current carrying capacity that can be produced at low cost and that can be located in assembly, including wire connections, with a minimum of time and labor, while at the same time assuring security and efiicicncy of operation.

The present invention aims to provide such a terminal aten block, the block being desirably molded from a material having a high dielectric value and melting point, preferably adapting itself to variations in color, and into which the metallic tcrminal may be inserted and retained a'nd the connectingwires secured to the terminal; without-the need for lugs, screws, nuts or special terminals on the wire ends. A thermoplastic material such as molded ny lon is preferred for the block.

An important object of the present invention is the provision of new and improved interlocking means, including cylindric tongues and cylindric recesses, by which adjacent blocks may be interlocked by a coplanar movement trans verse to the axes of the tongues and recesses, thus permit ting the blocks to be placed on a panel or the like and moved over the face of the panel to firm interlocking engagement without extraneous fasteners or preliminary interlocking manipulation.

A further important object of the invention is the provision of an improved metallic terminal that may be stamped from a fiat blank that has legs that cut irreversibly into the wall of the terminal block passageway to secure them in position, the terminals having end portions that can be curled into sleeves into which the bared ends of the conductor wires may be readily inserted and attached by a simple crimping action.

These, and other objects and advantages, will be apparent from the following description, taken together with the accompanying drawings, showing an illustrative embodiment of the invention, and in which drawings Figure l is a perspective view of one of the improved terminal blocks and associated terminal;

Figure 2 is a vertical longitudinal section taken on the line 2-2 of Figure 1;

Figure 3 is a cross-section taken on the line 33 of Fig. 2;

Figure 4 is a separated plan view of the terminal mem ber;

Figure 4a shows, slightly reduced, a blank from whic the terminal member of Figure 4 is formed;

Figure 5 is a collective perspective view of a terminal block and terminal and a barrier member that is insertable between blocks, the terminal block and barrier being shown separated for purposes of illustration; and

Figure 6 is a plan view illustrating the resilient interlock between cylindric tongue and cylindric recess.

Referring in detail to the illustrative construction shown ice in the drawings, the numeral 11 indicates the improved terminal block that is desirably molded of a thermoplastic material preferably such as nylon which has the resilient characteristics later more particularly referred to and which has a high dielectric 'value and high melting or softening point. In lieu of nylon, a polyethylene or vinyl chloride plastic may be employed.

The block 11 is shown having the usual central passageway 12 that is counterbored as at 13 to receive a mounting screw 14 for mounting the block on any suitable panel or the like. On opposite sides of the central passageway 12 are a pair of passageways 15 for the legs of metallic terminal member 16, shown separately in Fig. 4 and Fig. 4a. The underside of-the block 11 is desirably upwardly hollowed as at 17 to provide a lodging place for the terminal member as best seen in Figs. 2 and 3.

Further in accordance with the present invention, block 11 carries, on one face 18 (Fig. 1), a plurality of integral cylindric tongues 19a, 19b and 19a, and on its opposite face 20 (Fig. 5) has molded therein a plurality of cylindric recesses 21a, 21b and 21c. Each said tongue and recess is in the form of a partially cylindrical member a cross-section of which defines an interrupted circle having an are greater than 180 degrees. These cylindric tongues and recesses mate as later described, in adjacent blocks.

All of the tongues and recesses just referred to have tongue 19a-is-located-centrally of block 11 from end to end and adjacent the upper margin of face 18, while tongues 1% and 19c are spaced apart, endwise of block 11, adjacent the lower margin of face 18. Similarly, recess 21a is located centrally of the block 11, endwise of the block, and adjacent the upper margin of face 20, while recesses 21b and 21c are spaced apart endwise of the block 11 adjacent the lower margin of face 20. The tongue 19a of one block is received in the recess 21a of an adjacent block and the tongues 19b and 190 are received in recesses 21b and 21c respectively.

Further in accordance with the present invention, the tongues and recesses are interengaged, to interlock adjacent blocks, not by a conventional telescoping action, but by a movement transverse to the axes of the tongues and recesses, or, in other words, normal to the block faces 18 and 20, the material of the block, for example, the nylon I or the like, yielding to permit such interengagement and then springing back to prevent accidental disengagement.

As' indicated in Fig. 6, the diameter, say between the lines 22, for both the tongues and recesses, is slightly larger than the mouth 23 of each recess, indicated by the lines 24. Consequently a tongue must be forced into a recess having a mouth of a slightly less width than the diameter of the tongue, thus providing a secure interlock. When however, it is desired to separate adjacent blocks, this may be done by a pulling apart on the blocks sufiicient to cause the material of the blocks to yield for purposes of separation, the contour providing a cam action.

Further in accordance with the present invention, the novel terminal member 16 is, as suggested in Fig. 4a, advantageously stamped from sheet metal to the form of a blank shown. This blank has a base portion 25 that is centrally enlarged and perforated as at 26 to pass therethrough the mounting bolt 14 previously referred to. From the base 25 extend opposite legs 27, that have t of Fig. 4a is bent to U-shape and the terminal portions 34 are curled to split sleeve form 31 of a diameter slightly less than the passageway 15. In order to bring the axis of each split sleeve 331 into the plane of leg 27 so that the split sleeves can be passed through the passageways 15 in the block with the serrated portions of the leg coincident with the axis of both the'split sleeve and the passageway, the legs are offset as at 32. The base portion 25' is lodged on the upper wall of undercut or hollow 17 in the block. When the terminal is so assembled with the block, the saw teeth 28 of legs 27 dig into the wall of the passageway during assembly. This provides a substantially irreversible assembly (Fig. 3) since the legs cannot be moved in a downward direction without tearing the wall of, the block or tearing the teeth of the leg.

The insulating partition or barrier block 33 shown in Fig. 5-, may be inserted between a pair of :blocks 11, and

is of relatively thinner construction, but otherwise similar to block 11 and having the same arrangementof tongues and recesses thereon. Barrier 33 desirably has upstanding partition or guard-members 34 opposite each of the split sleeves 31 respectively to keep apant the wires which are intended to be connected to the split sleeves 31. The ends of the wires to be connected to the split sleeves '31 may be bared of insulation and inserted into one of the split sleeves 51, and then a conventional crimping tool may be used to permanently connect the wire and the split sleeve 31 together. Two wires thus connected to the split sleeves 31 of a given terminal are placed in electrical communication through the terminal member 16.

It will be noted that a recess 21;: has an end wall thooppositge or downward direction. Adjoining blocks can thus only be-interconnected by movementstransverse t o thc axes 'of the tongues and recesses. Consequently when a series of interconnected blocks is made-upon a panel, only the end blocks require the screws. 14,-thus being self-held from vertical movement. t v

Since mylon or a similar plastic material may be readily molded in dilferent colors, the blocks 11 may be conveniently provided in ditferent hues such as red, green, yellow, brown, and the like, each color having a different signification, thus aiding in application of the blocks to a variety of circuits by a minimum of etfort or knowledge on thepart of the workman makingthe assembly.

S0 constructed and arranged, I havedisc'losed :an'improved low-cost terminal block and terminal having Jen-. hanced .efiiciency and usefulness, particularly in the fields first hereinabove referred to.

I An illustrative embodiment of the invention having been described, in accordance with the statutes, such changes may be made, including modifications or additrons, as fall within the scope of the appended claims withoutdeparting from the invention. I What is here claimed is:

1. In an electrical terminal block of the multiple type embodying a dielectric resilient material and terminal 'effectinga saving in cost and time of assembly, the blocks cylindrical passageways therethrough, that improvement 60 wherein there are a plurality of cylindrical tongues extending from one face of the block" and a plurality of cylindrical recesses in the opposite face of the block, said tongues and recesses each defining in cross-section an in terrupted circle having an are greater than 180 degrees and having their axes extending parallel to said faces and being located at opposite margins of said faces, there being a tongue and an opposing recess transversely aligned adjacent each said margin, and an integral metallic terminal member spanning said passageways on the under face of the block and having integral legs extending up through the passageways, said legs having teeth thereon engaging the walls of said passageways and inhibiting removal therefrom, said terminal members terminating at a; their upper ends in preformed split sleevestowhich wires may be crimped respectivelyr 2. In an electrical terminal block, a body of molded thermoplastic material, a unitary metallic terminal memher having a centrally perforated base, a pair of legs extending in opposite directions from the base, said legs having saw teeth formed on their opposite edges, said teeth having normally transverse edges facing the center of the member, said legs at their outer en'ds being preformed into split sleeves respectively, said terminal block having a pair of passageways therethrough receiving said member legs by a force fit of said leg serrations --ther einto respectively, said passageways being of circular cross section to pass said split sleeves therethrough but being of a diameter slightly less than the width of said legs including said teeth.

3. The structure of claim 2 wherein the body has a central passageway 'therethrough registering with the "perforation .in the member base, and a holdmg screw through said central passageway and said perforation 4. In an electrical terminal. block oflthe multiple'type embodying a dielectric resilient material and terminal cylindrical passageways therethrough, that improvement h itto.recesses zlblanthgla.eachhavesendhwallsiBcfacingain he...

wherein there are a plurality of, cylindrical tongues-exa tending from one faceof the block and 1a plurality of cylindrical recesses in the opposite-face of the block, said tongues and recesses each definingincross sectionwan interrupted circle having an arezgi'cater-than 180 degrees and having their .axes extending parallelto said-traces and being located :at opposite m'a'rgins oftsaidfaces,itliere being a tongue -and art-opposing recess transverselyi'eflignedad jacent eachazsaidmargin zandintegral inetallici-termi nal.membenspanningsaiipassagewaysionefllcimderifaceinmt of the block andihavingiintegrallegs extending 11p through the passage'ways, said legs having'wire attaching elements at theiriupper ends respectivelw Ail.

5. In an electrical teiminal' bloch' a 'molded bodyaof resilient elastic thermoplastic material drawing-a :height, a width, and a length; a-ton'gne projection-on onela'te'ral 0 face of the body in the form 'ofapartially cylindrical element having its'axis extending in'ihedire'ction of the height of the block, a cross-section-.of which element defines an-interrupted circle havingan are greater than degrees, :said projection heiiagjoined-to the body of the block by}; connecting portion havinga width-slightly less than the diameter of said .cirelc, :-said projection ex tending axially fora distance substantially less than the height of the block, and'a recess on the oppositetem of said body also havingits axis'cxtendingin-the direction of the height of t the :block= and having zacross section describing. an interruptedcircle ihaving an greater than 180 degres and an open mouth interrupting said last mentioned circle having an opening slightly-less than the diameter of said circle, said recess also extending axially for a distance; less thanihe height ofihe block in register :With'said projection, the'diameters of said projection andzsaidrecessbeing approximately the same, whereby one block may be'connectedwith'adw' plicate thereof by a movement normal to the faces thereof to interlock a projection on one block with-a'recess in a contiguous block, the material of the blocks yielding therefor under the influence of a camming a'ct-ionof the cylindrical projectiomterminal receiving through-passageways in the block located centrally of the width of the block and spaced apart in the direction-of the-length of the block, and an integral metallic terminal member spanning'said passageways on the underface of the block and having legs extending up through -said passageways, said legs having wire attaching elements attheir upper ends,-respectively.

.6. In an electrical terminal block, a molded body of resilient elastic thermoplastic material having'a. height, a width, and a length, a plurality of three tongue projections on one lateral face of the body each in the form ofa partially cylindrical element having-"its axis-extend- 1 ing in the direction of the height of the block, two of ing in the direction of the height of the block and extending axially for a distance less than the height of the block, at least two of said recesses also being spaced apart in the direction of the height of the block in register with said projections whereby one block may be connected with a duplicate thereof by a relative movement in the direction of the width of the block to interlock the projections on one block with the recesses in a contiguous block, the material of the blocks yielding therefor under the influence of a camming action of the cylindrical projections and whereby relative movement of two interlocked blocks in the direction of the height 6 and in the direction of the length thereof is inhibited, terminal receiving through passageways in the block located between said faces, and a terminal member having legs extending through said passageways, said legs having wire attaching elements at their upper ends.

References Cited in the file of this patent UNITED STATES PATENTS 1,808,335 Aufiero June 2, 1931 1,826,869 Everett Oct. 13, 1931 1,936,963 Dutzmann Nov. 28, 1933 1,992,806 Benander Feb. 26, 1935 2,015,421 Eckstein et a1. Sept. 24, 1935 2,037,122 Despard Apr. 14, 1936 2,115,642 Martin Apr. 26, 1938 2,397,102 Graham Mar. 26, 1946 2,511,806 Macy June 13, 1950 2,680,235 Pierce June 1, 1954 2,726,375 Gordon Dec. 6, 1955 2,765,452 Tuchel Oct. 2, 1956

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