US2912670A - Terminal construction - Google Patents

Description

1959 c. D. FLANAGAN ETAL 2,912,570.

I TERMINAL CONSTRUCTION 2 Sheets-Sheet 1 Filed June 4, 1956 Roy's lag/ 74..

Nov. 10, 1959 Filed June 4, 1956 C. D. FLANAGAN ET AL TERMINAL CONSTRUCTION 2 Sheets-Sheet 2 Inventors: CharZes fl. Flanagan Roger W Hand,

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United States Patent TERMINAL CONSTRUCTiON CharlesDl Flanagan, Attieboro, and Roger W; Hood,

This invention relates'to' an improved terminal construction including a terminal secured to' anothermember such'as a base or' h'ousing member.

Among. the objects of this invention may be noted the provision'of'a'no'vel construction whereby a termmal' can be fiiredl'y attachedto" another member without the use of back-up means or the application of excessive.

forces, the provision of such a construction which is salvable when disassembled whereby the construction can be taken apart and reassembled without destroying or damaging any of its parts; the provision of such a.con

struction which readily permits repair and adjustment of I its associated parts, the provision of such a construction whereby one or morete'r'minals can be quickly, efii'cie'ntly,

simply and fixedly'cdnnected to' another member with the application of onlycomparatively light'force's andin volving only a simple bend'b'y means of a sirnpl'e' and conventional tool; and the provisionof such a construction which, is economicaL. novel'and' easy to' manufacture, assemble and disassemble. I

Further objects will become a'pparentas the description proceeds.

V The invention accordingly comprises the elements and combinations of elements, features of construction, and

arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, I various possible embodiments of the invention are illustrated:

Fig. 1 is a fragmentary perspective view of a base or housing member, which forms partof the novel construction according. to. one embodiment of the invention;

Fig. 2 is a fragmentary perspective view of a pair of terminals fixed-1y" supported on a terminal-carrying member which alsoform part of the novel construction according to this embodiment;

Fig. 3' is a fragmentary perspective view of the parts shown in Figs. 1 and'2', respectively, theseparts' being shown inlassembl'ed relation; I I

Fig.' 4 is a view similar to' Fig. 3 but showing the parts secured together according to this invention; v

Fig. 5 is a fragmentary sectional view taken along line 5f5 in Fig} 3; V

Fig. 6 is a fragmentary sectional view taken along line resin F Fig. 7 is'a view similar'toFi'g. 6 but showing a portion of the terminal secured to the'base member according to one process; I

Fig. 8 is a view' similar to Fig. 6 but showing a free end portion of th'e terminal in its deformed position at h the terminal is securedto the base. member accord- I 0 another process; I I, Fig. 9 is an elevational viewpartly in. sectionof' a terminal in assembled relation with a portion of a bas'e member according to another er'nbodiment of this invention;

in which several: of

2,912,670 Patented Nov, 10, 1 9,

Fig: 10is a'view similar to Fig; 9' bu t;sh'owing theparts in secured relation according toione process; I

Fig. 11 is a; viewpartly inrsectio'nf taken 'along line 11-41 in'Fig; 10; i v

Figs. 12'and 1'4, respectively, are elevational view s of two other alternative terminal structures which fallv within the scope of. my invention; and Figs. 13 and 15 are elevational views partiallyin section .talgen; from the right-. handside of'Figs. 12 :and 14, respectively.

Similar reference characters indicate corresponding,

parts throughout the several views offthedrawings,

The word terminal ispintended"throughout this specification to mean any current conducting prong;

I Referringto Fig: 1, ahollowbase or base member 10 is shown to which it is'frequentlydesirable to secureone or more terminalsforfthe'purpose. of electrically com; municatingbetween the'interiorland' exterior of the base. member. Twoterrninals .11 which come within the scope of the invention are? shown in Fig, .2; These terminals may be secured'in any appropriate manner to. a common terminal carrier '12 as; shown in Fig, 2. By way of example,,terminal carrier 12 may. combine with terminals 11, 1'1 and additional" components (not shown). to forrn an insert 13'for an electrical switch, Since the operating mechanism of the' switch. forms no part of theinvention,

this I specification. will not be unnecessarily; complicated by a detailed'description thereof. H

' Ba semember 10 provides an exterior surface 14, to which agu'ideway; or aperture 15 opens-from, the interior. of the base memberi. Adjacent eaclr of guideways. 15 is a' surface portiorr.16"whichmayappropriately betermed a reaction surface. Surface portion 16 may be, provided as shown in the drawing the inclined bottom of. a rectangular groove or channel; I

Each of terminals 11 includes a free-(end. portion. 1'1 which may be provided wither; aperture 18 for. the. con: nection of,that terminal tojan electrical lead or. the like. The'f ree end -portion 17 of'ea ch of terminals 11' provides a substantially U-shaped slot '19 to form a cantilever member or'l'ug 20'." Cantilever'lug 2g is therefore integral at one end with terminal end. portion, 117iand extends; to its free end alongthe plane-ofthe remainderofterminal portion 17 Thewidth of the U-shaped' slot may from a somewhat, comparatively larger Width than: that shown in Fig. 5} to the extent that: it comprises a. mere. slit.

Beforedescribing the methods by which each: of terminals 1 1 along with. terminal carrier 12 is secured or affixed' with respect to base member 10', it mightibe well to' 'expl'ain that each of terminals 11 is composed'offa suitably bendable, electrically conductive material. such as Monel, brass, orcopper. Base member 10 may be formed of a suitable electrically insulating material. such as the customary molded plastics, ceramics,,etc-

In assembling insert 13, with base member 10, the insert is aligned with the hollow portion of the, housing and. moved thereinto to bring the free end portion 1.7 of each of terminals 1-1, 11 to the outwardly projecting position shown in Figs. 3, Sand 6. It will be noted-that longi tudinal movement of each of terminals II, in its direction of insertion is limited by the engagement of surface 21 of member 12 with interior surface 2210f base member 10. Although the fit of each of terminals 11 in its respec tive guideway15 may be relatively loose, eachtermin'alis substantially confined by that guideway and/or the'interfitting surfaces of base member10 and insert13 fonlongi tudinal movement; r p

The terminals-ofthis invention can now be secured to their respective base member by either of two preferred 1 methods-Which will be described below. '7

identical with the other, and since each terminal is or may be secured to its respective base independently of the other, a detailed description of the methods of securing only one of the terminals to base 10, after assembly therewith, will suffice for both.

With a terminal 11 in its fully inserted position with respect to base member 10 as shown in Figs. 3, 5 and 6, it will be noted that the extreme free end surface 23 of cantiliver lug 20 has been moved slightly past the innermost edge of reaction surface 16.

To secure terminal 11 with respect to base member 10, free end portion 17 of terminal 11 is deformed to the left as viewed in Fig. 6 to substantially the position shown in Fig. 8. Although it is not necessary, an auxiliary block or tool 24 may be positioned as indicated in dotted lines in Fig. 8 against which the terminal may be deformed. Either of these alternatives would prevent a stress concentration in the material of the base such as would occur were the terminal deformed against corner 25 of the base member. The zone within which the terminal is transversely deformed must be within one extremity defined by the free end of cantiliver lug 20 and another extremity at or closely adjacent the fixed end of cantilever lug 20. Since the effective deformable width of the terminal 11 at this zone is obviously limited to those portions of the terminal between each of its side edges and the edge of U-shaped slot 19 adjacent thereto, it is apparent that the terminal is more readily deformable at this zone than at other sections along the terminal.

During this deforming step, cantilever lug 20 swings outwardly from the adjacent portion of the terminal to bring the free end of lug 20 into jamming engagement with reaction surface 16 as shown in Figs. 4 and 8. The angle which reaction surface 16 forms with the axis of guideway 15 is such that once the free end of lug 20 first engages the reaction surface, continued swinging movement of the lug continually increases the jamming effect between the lug and the reaction surface. More particularly, during swinging movement of the lug 20, the tangent of the curve traced by the free end of the lug forms, at the intersection of this curve with the reaction surface, a substantially greater angle with the axis of the guideway than that formed by the reaction surface with the axis of the guideway.

The result of this jamming effect between lug 20 and reaction surface 16 is to draw or force stop surface 21 of member 12 against surface 22 of base 10. The greater the jamming effect, the greater the force will be with which surfaces 21 and 22 are drawn or forced together. Accordingly, with the free end of lug 20 jammed against reaction surface 16, surface 21 is maintained tightly against surface 22. and the terminal is effectively secured to base member 10. In fact, the fit of the parts can be such with this arrangement, so that substantially no movement, lateral or otherwise, of the terminal with respect to the base or housing will ensue during even hard usage under adverse conditions.

It will be noted that, within the above-defined deformable zone of the terminal, the closer the line of deformation of the terminal occurs to the fixed end of the lug, the farther the lug will swing outwardly from the adjacent portion of the terminal and the greater will be the jamming effect. Depending upon the length of the lug 20, the dimensional tolerances of the parts, the jamming force required and the proximity of the line of deformation of the terminal to the fixed end of the lug, it is well within the purview of one with only ordinary skill in the art to vary the angle which the reaction surface forms with the axis of the guideway for optimum results. According to one construction of a form similar to that shown in Figs. 1-6 and 8, the reaction surface is disposed at an angle of 45 with respect to the axis of the guideway, the lug has a length of .187 inch from its free end to its fixed end, and the smallest allowable dimensional tolerance for any of the parts is set at .002 inch. W h

these dimensions and this tolerance, the jamming effect is suificient to secure the parts together so as to prevent any movement of the terminal with respect to the base member.

It should be particularly noted that during the abovedescribed deformation step, the forces exerted on the terminal always tend to draw or force stop surface 21 of member 12 against surface 22 of base 10 while jamming lug 20 against reaction surface 16. These effects are in opposition to each other and the result is that no back-up means is required to secure the parts of this improved construction together, in contradistinction to the requirements of conventional constructions. The term back-up means, as used throughout this specification, refers to such means as might be used to hold the parts of the construction together while they are being secured.

Frequently it is desired that the interior of the housing be closed off or isolated from the circumambient atmosphere, in which case a suitable sealant may be applied about the opening in surface 14 formed by guideway 15 and reaction surface 16, and against the adjacent sur faces of terminal 11. In this regard, a sealant which is frangible after setting or otherwise expendable may be utilized such that if the assembly should subsequently be disassembled, the sealant could be forcibly removed without concomitant damage or injury to any of the parts of the assembly.

It will be clear that this improved construction permits terminals 11 to be disassembled from the base 10 by the simple expedient of forcing terminal portions 11 back to. the relatively straight conformation shown in Fig. 5. Such movement is effective to swing the free end of lug 20 away from reaction surface 16 whereby the terminals can be withdrawn from the base. Since this construction is so readily manipulable for disassembly purposes, it is obvious that repair and/or adjustment of the construction and its associated parts can be quickly and efficiently carried out. It is also to be noted that the allowable dimensional tolerances for the parts of this construction are ordinarily well within the range of modern mass-production control.

To deform the terminal as described above, a conventional pair of pliers, with or without tool 24, may be used thus rendering the parts of this improved construction capable of being effectively secured in the field. or at its location of operation. It will be readily recognized by those with only ordinary skill in the art that, in mass production, a simple reciprocable press having a bending die would be effective, with or without tool 24, to carry out the above-described deforming step.

Another method of securing the terminal and the base member of the construction shown in Figs. 1-3, 5 and 6 may be used. With the terminal 11 in its fully inserted position as best shown in Figs. 3, 5 and 6, a force may be applied by an appropriate tool (see Fig. 7) against lug 20, to deform the lug to bring its free end 23 into jamming engagement with reaction surface 16 as shown in Fig. 7. The effect is to force surface 21 of carrier 12 tightly against surface 22. of base 10 whereby terminal 11 is effectively secured to base 10. It is sometimes desirable to place a reinforcing member against the oppo site side of the terminal from that at which the lugdeforming tool is applied to prevent unintended deforma tion of the terminal during the lug-deforming step.

During application of the deforming force according to this alternative securing method, surfaces 21 and 22 are always forced together and it is therefore clear that, as with the previously described securing method, no back-up means is required during the securing operation. One application when this alternative securing method is advantageous arises when it is required or desired that the outwardly projecting portion of the terminal be sub stantially straight.

The angular relationship between the axis of the guideway and the reaction surface for this securing method sis-12,676

will, of course, be substantially the same as and will be determined by the same factors as those stated above with. respect to the first-described securing method.

Among other advantages provided by this alternative securing method and besides obviating the use of back-up means during the securing operation, many of the other advantages ascribed above with respect to the first-described" securing method are provided. That is, a suitable sealant may be applied as described above; the terminal is readily separated from the base member (by merely deforming the free end of lug 20 back within the confines of the remainder of the terminal) Without damaging either the terminal or the base member such as to militate againstre-use of these parts; repair and/or adjustment of the construction and its associated parts can be quickly and e'fiiciently carried out; a simple tool may be used to effect the deforming step whereby the parts of this construction can be effectively secured together in the field or at its location of operation; and the dimen sional tolerances of the parts are well within the range of mass-production control.

Figs. 9-11 illustrate another constructional embodiment falling within the scope of the invention. In this embodiment the base member is in the form of asubstantially flat plate or block 27. Base member 27 is composed of a suitable electrically insulating material such as the customary molded plastics, ceramics, etc., and is provided with a guideway or aperture 28 and reaction surface 29 which are substantially identical in structure and functionto guideway and reaction surface 16, respectively, of the constructional embodiment shown in Figs. 1-8.

The embodiment shown in Figs. 9-11 further includes a terminal 30 having a free end portion 31 which is substantially identical in structure and function to free end portion 17 of the embodiment shown in Figs. 1-8. That is, aperture 32, cantilever lug 33 and U-shaped slot 34 in terminal 30 are substantially identical in shape and relative arrangement to aperture 18, cantilever lug and 'U-shaped' slot 19, respectively, in terminal 11. T erminal 3:0 is composed of a suitably bendable, electrically conductive'material such, for example, as Monel, brass,

or copper.

The embodiment illustrated in Figs. 91l demonstrates to some extent the wide variation of the particular forms this improved construction may assume. In this embodiment the means for limiting the extent of insertion cr-extent of longitudinal movement of the terminal in one direction is the surface 35 which is properly disposed when the terminal is bent at 36 and return bent at 37. With terminal 30 fully inserted as shown in Fig. 9', free end portion 31 is then deformed to the left as viewed in Fig. 9 to the position shown in Fig. 10 and in the manner described above with respect to Fig. 8. With free end portion 31 so deformed, free end surface 39 of lug 33 is jammed against reaction surface 29 as shown in Figs. 10 and 11. The result, as with the embodiment illustrated in Figs. l-6 and 8, is that surface 35 of terminal 30 is drawn or'forced tightly against the adjacent surface of base 27 whereby terminal 30 is effectively secured to base 27. Not only can the parts of the corn struction shown in Figs. 10 and 11 be disassembled with out such damage thereto as would militate against reassembling and securing the same parts, but all of the other advantages ascribed above with respect to the embodiment and securing method shown in Figs. 1-6 and 8 apply as well to the embodiment shown in Figs. 9-1l.

It will be obvious that many different forms ofstop means may be providedin fixed relation to' the terminal to limit the extent of its insertion along the base mem' ber. Fig: 12 illustrates one of these many forms in that the terminal 41 is provided with a pair of extensions or projections 42, 42", each of which provides a shoulder 43 for cooperation with an appropriate portion of the base member to limit the extent of movement of the terminal in one direction with respect to the base member.

Figs; 12 and 13-, and Figs. 14 and 15, respectively, il"

lustrate two other forms in which the cantilever lug may between two transverse extremities one of which is coex tensive with the free end of the cantilever lug and the other of which is coextensive with the fixed end; of the cantilever lug. A terminal of the form shown in Figs. 12 and 13 is of great'advantage when a greater currentcarrying capacity of the terminal is needed. Obviously, with everything else being equal, the current-carrying capacity of terminal 41 which has no slotted portion adjacent the cantilever lug will be greater than that, for example, of the terminals shown in Figs. 1 8 and Figs. 9 11, respectively.

The alternative terminal structure illustrated in Figs. 14 and 15 is similar to that of Figs. 12 and 13 in that a separately formed cantilever lug 48 is secured at its one end to terminal 47 by a weld 49 or its equivalent. The structure of terminal 47 is different from that of ter minal 41 in that an aperture is provided thereby adjacent cantilever lug 48 at the deformable zone. A terminal having the form shown in Figs. 14 and 15 has the advantage, as does a terminal of the form shown in Figs. 1-8 and Figs. 9-11, respectively, of being more readily deformable at the deformable zone than a terminal such as that shown in Figs. 12 and 13. This feature becomes advantageous when the current-carrying capacity of the terminal need not be so great and the particular material of wlhlich the terminal is composed is not readily deforma e.

It will be understood that any one of the cantilever lug structures disclosed herein may be utilized with any one of the stop means arrangements disclosed herein, and vice versa. For example, the stop means comprising proections 42, 42 shown integral with terminal 41 in Fig. 12 could be eliminated therefrom and this terminal could then be mounted on a terminal carrier which provides stop means as in the embodiment shown in Figs. 1-8.

As many changes could be made in the above construction and arrangements of parts without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustratrve and not in a limiting sense.

We claim:

1. In combination, a base member, and an electrically conductive terminal, said base member providing a guideway, an exterior surface and a reaction surface, one end of said guideway terminating at said exterior surface, said reaction surface diverging from said guideway toward said exterior surface at an angle to said guideway, said terminal lying in said guideway and having a portion projectingoutwardly from said base member and past said exterior surface, said terminal carrying stop means abutting said base member to prevent movement of the terminal in one direction along said guideway, said terminal carrying a lug having a free end'and adapted to be bent to swing said free end in an are, said free end of the lug when bent being jammed against said reaction surface to prevent movement of the terminal in the opposite direction along said guideway, the tangent of said are at the point of jamming making an angle with said guideway not less than the said angle of said reaction surface.

2. In combination, a base member providing a guideway extending therethrough, said base member having an exterior surface, one end of said guideWay opening to said exterior surface, an electrically conductive terminal having a first portion disposed in said guideway and a second portion projecting outwardly from said first por tion and past said exterior surface, means carried by said terminal and abutting a portion of said base member tc prevent movement of said terminal in one direction along said guideway, and means to prevent movement of said terminal in the opposite direction along said guideway, said last-named means including a reaction surface pro vided by said base member and, in said first direction, diverging from said guideway to said exterior surface at an angle to said guideway, and said last-named means further including a lug carried by the projecting portion of said terminal, said lug having a free end portion and adapted to be bent to swing said free end portion in an are, said lug, when bent, being disposed in jammed engagement with said reaction surface to press said firstnamed means tightly against said base member portion and thereby secure the terminal to the base member, the tangent of said are at the point of jamming making an angle with said guideway not less than the said angle of said reaction surface.

3. An electrical switch construction comprising a hollow base member providing an external surface and a guideway opening to said surface from the interior of the base member, said base member further providing a reaction surface extending between said external surface and said guideway, said reaction surface being angularly disposed relative to said' guideway; an insert for said base member including an electrically conductive terminal having a portion projecting through said guideway, said insert further including a terminal carrier fixedly secured with respect to said terminal and having a surface in engagement with said base member to limit movement of the insert along the base member in one direction, said portion of the terminal including a lug, the free end of said lug being adapted to be bent to swing said lug in an are; said lug, when bent, being disposed in jammed engagement against said reaction surface whereby said terminal carrier surface is pressed against the base member to secure the terminal with respect to the base member, the tangent of said are, at the point of jamming, making an angle with said guideway not less than the angle of said reaction surface.

References Cited in the file of this patent UNITED STATES PATENTS 2,312,795 Brownstein Mar. 2, 1943 2,537,820 Flood Ian. 9, 1951 2,579,841 Ludwig Dec. 25, 1951 FOREIGN PATENTS 149,753 Australia Ian. 29, 1953

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