US2506398A - Cable connector toe-in-type - Google Patents

Description

y 1950' G. c. THOMAS, JR 2,506,398

CABLE CONNECTOR TOE-IN-TYPE Filed April 29, 1947 IN V EN TOR. 654865 6 [yo/114$ (/2. BY

Patented May 2, 195

"to, The Themes & BBI tSQ QQ E zabeth,

a. 9 jP?' Qn' 9 :Nj e

Application. April: 29, 1941,;SerialvNo. 744,556

i .mme at to p ide oni i .n -J bu ar m m e di n a hole provided threfo r' in the wa l-1 0:" gm opiql et gto-which tubl ii ar member is inigz uded wily with {a1 ira ,w m dv mien}? mie w edwa-eliifia le dam in r n eni of unshaped fogip hav ir g; its l egs exigen digg psiwlle J h et er: and. etheg hier the table and passed through elot s .mthe sigie oiiialqz henneei r' m i ii e ne 1 tr d fl m N In iheprior art where the u-slie peq-rfo mo' f iciar z psghevei been employed, it was. foili'id i1 0 be o f advax iage to cegiisefthe legs qf the ciem p tp engigel the. cable pmn ltlgreto and in; trap siverse y ofi rela i to h rew wi ne her ab e spe ly n h case W r-Mh @191 n ase n f uai q :me l ifis i 19 armpit: Whiqh is apt be. cn i shed ii 120,0 greai; a xesur pp ,id 1 cr wn; t on P pri r; It fle qeim ss e eue ds mews-Wt he ca le i pmt aheiii deg ees wit or a ong es ea firm ng; n, ense Q 99 4? :4

' w, he line-119i. hr st of h T- s QQZ gla lppipg screwf Itis the intent hel ein to re the e of we mew;i lam i qme ne- 'l fheirequirenilent that thelpregeureir x pegeglmn Ilia a ijr'rib lned cable form an air; 1e of boi t .pinqiy ,l e rw h a??? not lh c b nm ni. that; or erech iiie ni. .7 Q QnQ QtQI-M to be cu t m-fi o ea h na .ti ;u 1arf size of .xx iole. C or sidering theizima igy difjfgrenteizespf cables are used in 'conneetiqp with .Qutlet jbqzgee, it is economipal ly iinppsgible th cable to be used.

Awqm n lyw he pr mar b ct-OM in izio n to prpyide. a" sigxridzair c1'v one ksi zefliorn .o f ae ze iq ar i ul lyn. t l m ie ut h .e fim itiher oil w ich, an lamnnabl s f r M 1 Qifleren diam i ra an atihe sa M re thee van ese f t a m xim tely nin 9 e; nga em with; s i m fiv i e ee v of its size, at least within Jim s.

the cable at abou t the same relative :IJO iIELtS con: sidered angulgrix ar q at leaet tofsonie exter'it inde end n l 1 the diametef iof the cable ihlils 011.13 etime being.

V io s ophex objects andiadvantages of the veg tipr will bein, partipbvibtisufmm nlinsiae of .thfiaQCQljIlPEfllYiIlg gnawing and in par-c m9 l1yset forth-inthel' llo in r i description of twp formgigi device'embedy g; inveni qm n h Y n= l o s s t i nd Yl--f? 1 l f' n ir mti cnmbinatiqn of pgyiis hereinaftei set fotiih lai d I .i

Inithe accompanying, drawings; I

'Fig. 1 is a n ezgploded View showinga preferred embgdimeni: ofqthe invention;

Fig" 2 is a secmppa view'ta ke n iaxiaily thmugl theiqeyiee shpwr i inEig. I and sho'wri mfcip'r fijie 'gosi'tion seeming a1; aijmqureq, cable to. gn oujiei 0X;

Fig 3 is a pla n. .view. of a. v stamped. sheet metal plankfmm which'tne tubular; memberpf the p goceeding figures isiformedl;

Fig, 4 is a transverse sectional .view itak ripr .j;he .1i;1e 4- 4 0i F ig- 3 and sh oiwviing a suclc'ee ng sitepvin, Jqhe foml a gion (if the embpsse'd part0 "the b l f gmbe i M V, e i

Figs; 5 and fi a eeach traps ve 'sersec iiionel mews taken' on the line 55-5, of Fig.2 Fig. 5lS1iQw'iln the in 30 c lampir gwelemeni; in gdisjer'igedpflsition ng a ais a Pla WJQOkmg down oniahe clamp: ing el men .Of F gs, 1, 2, 5, s with screw in positipp;

igg. 8 any; 9 cgrgespond respectively tp igi e iarf .-s enamtek ized PQ I Qt rS 'mr ea h T z pi A0 showin is. in .Fi 7 W 3 ii w -Da t clamping element in ditinction from thie 013$ pait clamping element shown in theprecd in -Lfi u r es gjFigrhseshqvgingjr doigted and f lines, Succ n fiif l of he peri wi m rkw i l a; able r m (which hw blan 's mel ible n: .1; .5

and 6.2 15 fpgmeg',

, In. th drawin s ans; eferrin first .fio Sine Pie..- ferred form of theinvention 'shown in Figs; 1

spiral groove form comprising one or more cor rugations G forming a deep trough H between succeeding turns of the corrugation. The end of the cable to be intruded into the bore of the connector is usually prepared by cutting back its armour to form a squared oif abutment end I and into this end is inserted bushing 0 designed to fit squarely against a stop therefore forming part of the connector herein featured.

In the showing of the small size cable in Figs. 6-

and 9, the corresponding parts are similarly designed with the characters primed.

Referring to the showing in Figs. 1 and 2 for a description of the preferred form of the invention, there is disclosed a metallic connector in comprising a shell or tubular member I l of somewhat cylindrical form and which is provided midlength with an outwardly projecting angular corrugation l2 acting-to form a stop for limiting the intrusion of the member 'Il into the box hole B as is usual with such connectors. The end of the member II which projects outwardly from the box forms a barrel [3 on one side of the corrugation l2, and the portion which extends through the opening B and into the interior of the box forms an extension I4 exteriorly threaded as shown at I5. The threaded extension 14 is provided with a flat nut I6 bearing against the inner wall of the box A to receive the box wall between the nut and the corrugation and in general this part of the structure follows known practices in this respect. The bore ll of the member H is partially closed at its inner end by a set of circumferentially spaced apart fingers l8 forming a bushing through which the conductor forming core portion of the cable may extend and which forms a stop for limiting the intrusion of the armour F and to form a closed joint with the abutment end I of the armour.

The upper side of the barrel is punched outwardly as hereinafter described in discussing the blank of Fig. 3, and the punched portion bent from the plane of the balance of the blank which is to form the barrel to form the offset embossment [9 constituting'a support for the clamping means hereinafter described. The top surface 20 of the embossment is fiat and inclined toward the adjacent open end of the barrel I3 at a small angle to the axis of the bore I? and thus at a small angle to the axis of the cable 0 as best shown in Fig. 2. The embossment is provided centrally thereof with a screw hole 2| which extends therethrough perpendicularly to the top surface of the embossment. The portion containing the screw hole is drawn inwardly as more particularly shown in Fig. 4 to give the screw hole some material depth and is tapped to provide it with screw threads 22. The barrel H in narrow slots 23-24 on opposite sides of the screw hole 2| and each extending for a material distance longitudinally of the length of the connector and thus of thecable intruded into the same. r I

The connector also includes a shiftable clamp the upper side thereof is provided with two long or clutch element 25 in the form of an inverted U and comprises a flat bight or crotch portion 26 overlapping the top surface 20. The U-shaped member includes two legs depending from the crotch portion in somewhat parallel relation and including a left leg 21 and a right leg 28 as viewed in Fig. 1.

The crotch portion 28 is provided centrally thereof with an unthreaded loose screw hole 29. The clamp element is disposed in position straddling the embossment [9 with the left leg 21 intruded through the slot 23 and the right leg 28 intruded through the slot 24 in both cases into bearing engagement with the cable C in the bore IT. A screw 32 is provided with a wide bearing head 33 for bearing on the crotch portion 26 and has its shank passed loosely through the unthreaded screw hole 29 and in screw threaded engagement with the long threaded hole 2|.

The particularly novel feature of this disclosure is that the inner or free end portions of the legs, that is, the portions which are intended to engage the cable and herein marked respectively 30 and 3| are toed-in or bowed-inward towards each other as shown in Fig. 5 and Fig. 6. In the instant case each of the lower toed-in portions 30 and 3| forms an angle of about twenty-two and one half degrees with the axis of thrust ab of the screw 32.

The lower cable engaging edges of the toed-in portion 30 and 3| are designed to engage the cable on opposite sides of its crown somewhat resembling known structure in this respect. In the case of the portion 30 of the left leg the lower edge is provided for the major part of its length with a smooth face 34 for engaging on top of the corrugation G and at its forward edge with a finger forming extension 35 somewhat V- shaped in side elevation and designed to intrude into one of the troughs H of the cable armour. The other portion 3| of the right leg 28 is similarly contoured but in reverse direction, that is, the forward portion of the edge provides a smooth face 36 and at its rear end is provided with the V-shaped extension 3'! intruded into trough H as shown in Fig. 2. The extensions 35-31 are spaced apart longitudinally of the axis of the bore l1, and thus of the cable intruded therein, a distance equal to the spacing of the troughs between succeeding turns of the corrugation G or rather of the turns of the trough.

In order to provide some degree of flexibility between the crotch portion 36 and each of the legs 21--28, it is suggested that the four corners of the crotch be notched or cut away slightly as shown at 38 in Fig. 7, so as to provide between the notches a corner hinge 39 between each leg and the crotch portion, with less cross sectional area of material in the hinge forming edges than would be present if the corner notches 38 were not made.

The line of thrust imposed by the screw 32 on the clamping member 25 isindicated in Figs. 5 and6 by the lineo.b passing through the axis of the large cable C and through the axis of the smaller cable C. The lower portions 30 and 3| of the legs are inclined towards each other at an angle of about fifteen degrees with the thrust line a--b as indicated on Fig. 5.

Referring to the modified form of clamping element shown in Figs. 8 and 9, it will be understood thatthe structure in general resembles the one piece clamping element 25 except that it is made of two parts, 40 and 4|, each of approximate inverted L-shaped form and with their outer her in circumferentially spaced apart pairs to :55

acct-gees regs-I2 and Ilambveinpping renucn. The over: la ping legs are provided with allg ned ltios' screw heles u-"corressbnaing to the 'scr'ewholeflin the preferred form and similarlydesigned'to reeeive the screw 32' passed 'ther'ethroug'hand into the screw hole 2|.

In'this'for in "of the clamping element-the toedlaypersonsof' each leg, that is, the portion 7 4'5'of the-left leg"!!! and the part 46 of-the right'leg 4-I each-forms an angle of fifteendegrees with its ails-"of -screw-pressure along the thrust line o -b. Irrespective as to whether the single clamping -member- 25 or the two part --c1amps MI 4] is used, in either case the pressureedg'e '0'1} feet formed as indicated'at"34 31of'Fig: 1 bears on the large diametered cable C respective ly at points 41 48 disposed relative to the center or iris-50 of the cable to form in each case an angleof forty=fivedegreeswith the line of thrust a bf'o'ra total included angle between the lines 50 a and Sitd of ninety degrees as shown in Fig. 5. The toed-in portions 30 and 3I'each form with the axis of thrust a-b an angle of twentytwo andone half degrees as indicated by the angles ej -a and a fg. In the case of the "cable C of small diameter the pressure feet engage the cable at'corresp'onding disposed points '41 and 48' and likewise form an angle 'of forty-five degrees from the center 50' of the small cable C as indicated by the afl i smsu a and a 5l''-z'. Theblank as shown in Fig. 3 from which the tubular member II is formed comprised initially a long flat rectangular strip' of thin bright rolled sheetsteel', with rounded edges, die-punched to shape. There is formed'at'one short end a dovetail recess K and at the opposite end a similarly shaped projection L, one fitted into the other to foiin inthe finished memb r II ahinteilockiflg joint M shown in Fig. 1. This joint is not required to resist radially directed strainswhich might tend'to open the joint as 'the member I I is fitted somewhat snugly in the circular opening Bin the wan ofthe box. The long fiat joint illustrated is well adapted tore's'ist any tendency of the member II to open at the joint M by reason of 'anyrei tive longitudinal shifting of thepaitS on'o'pposite' sides of the joint. I

Alon'g'one long sidethe'blank is'pr'ovidedwith 'foufspace'd apart lugs N subsequen'oy' bent as shown in' Fig. 4 at right angles to the balance "thestrip to form the stop fingers 18 f Fig. 2. The "fingers are arranged in the fin'ishedtubular memp'rovide' therebetween a pair'of diametrically disposedclearances shown'in detail in the compan'ion application, and arrangedto accommodate there- 'b'etweenthe opposite edges of the core portions of cables of'differentdiarneters. Inthe'staniping operation Which forms the blank of'Fig. 3the corrugation I2; the slots 2324 ahd'thethen'unthreaded screw hole 2| are 'formedat'thesame time the balance of the blank is shaped in its "outline. Subsequently the embo'ssme'nt I9 is'die unched into the'inclined position shown in Fig.

4; the portion surrounding the hole 2| is drawn ihwa'rdlyby appropriate die "action to 'provide the requisite length to the tube as'best shown i'n'Fi'g. 4, and the hole so enlarged from the initial hole t'l is finally tapped to provide the'necessaryextent of threads 22, all before the'blank is'rolled intoits final cylindrical form. The dove-tail ends are then interlocked to complete thetube H and the extension |'4- thereof isexternallythreaded' to provide the" external" nut engaging threads I The clampelementfi is also stamped-21min sheet steel'at the timefits screw hole 29 is formed and thenthe're'sulting blank -a's shown in :10 is bent conventionally: into the u-tform withhits toad-in portions as disclosed in'Figs. 5:.and '6. :The two-part rorm' of clamping device shown in Figs.- 8 and 9 are formed conventionally-Ion; a: plate bending machine.

Inoperation'and assuming that the con'n'ector hasbeen either presecure'd or 'su bsequentlyise curedtothe outlet box,xand that a cable','-i.'such as the large size cable, shown in Figs. 2 and- 4A5 intruded in place-in the bore I 'I: with 'thecabutme'nt end I-ofits armour F engaging against the stop I8; theclampihg element and screw areas-- sembled' 'as indicatedin Fig. '2- if not already in' place "Beforepre'ssure is'applied by the screw on tothe cable',--- the cable as a whole 'rotated about its own axis until the forward projectioiri-i-engases in a forward turn of the trough andthe rearprojection 31 engages in a' portion "oi-the trough spaced 1 outwardly therefrom, that is as the right'thereof as indicated'in' Fig. 2. The screw 32 is then advanced to force the coupling element inwardly. The 'force applied at the'b'ot tom edges of the clamping member, that 1s through surfaces and 36 and through fingers 35 and 37 may be'resol-ved into two components; one-acting more or less conventionallytransverse ly of'the leng'th of the cable, andtheothei. acting longitudinally of the length of the" cable'and towards the stop I8 in such way as to force the "armour end I into firm abutting re'lationtothe stop I8, all as more-fully described in the above identified copendingapplication.

For ease'in comparing theaction'o'f the bowedin legs 21-28 of the clutch e1ement'25',.when cables of different diameters are used 'there'is' shown on the outline o'fthe larger cable" 0,1 a cable C of smaller diameter. Assuming thatlt is intended to clamp in "the connector a cable'of relatively smaller diameter such as is shown at C in'Fig. 6 the same clut'ch'element25is"used as'was'used with the larger cable. As the element '25 advances by reason of the screw lo'ad inwardly fromthe' Fig. 5 position the free endportions 30-3! bear respectively on the outer edges of the slots 23 and 24. This causes each of the legs?! and 28 to swing inwardly towards the thrust :line d-b swinging about their corner hinges 39- the two legs'move'radially more and more inward 1y; their points of contact likewise move bothinwardly'and towards each other from their maximum spread apart positions 41-48 towards their final contacting position engaging the smaller cable C" at the points 41' and 48' as shown in Fig. 6. The parts a're'so designed that in their fi'n'al as well as in allin'termediate positions the angles formed between'th'e' lines of thrust of the legs 21-28 intersect and form therebetw'een an angle of'ninety degrees.

Referring to the two part clamping. element shown in Figs. 8 and 9, it will'be understood that in mounting' it in place, the screw "32 is removed or almost so, and the two parts angled into the slots 23 and 24 as may be most convenient and assuggested by the dotted line showing in Fig.8. The two parts when finally in position tend to assume the full line position shown in Fig. '8.

Intneshdwifig in Fig.8 wherea lar e 'srzecabie is used the two-part clamping, element corresponding to the one-piece clutch element 25 is relatively outset from the tubular member M, and has its pressure edges or feet engaging the cable at the ninety degree offset points 4? and 4.8 in the same way as has been described for the preferred form of the invention. In the showing in Fig. 9 the two-part clampin element is relatively further intruded into the tubular member H to engage the smaller cable C at corresponding ninety degree separated points 41 and 48.

It is thus seen that irrespective as to whether a large or small diametered cable is used, and irrespective as to whether a one-piece or a twopiece clutch element is used, the bowed-in legs of the U-clamp will engage the outer surface of the cable at points about ninety degrees apart.

I claim;

1. In aconnector for securing a spirally wound cable to an outlet box provided with a hole in a wall thereof, said connector including a tubular member provided with means for securing it to the hole in the box and adapted to receive the cable in its bore, a portion of the side of the memher being offset to provide an embossment extending at an angle to the axis of the bore, having a threaded screw hole extending perpendicularly therethrough and provided on opposite sides of the .embossment with a, pair of longitudinally extending slots, means for clamping the cable to the member and including a clamping element of inverted U-shape straddling the emboss-ment and having its legs intruded through the slots and into the bore of the member, the intruding cable engaging ends of the legs in the portions thereof designed to intrude into the bore, being bowed-in towards each other to form an acute angle therebetween and fashioned for engaging the adjacent side of the cable along parallel lines on opposite sides of its crown portion irrespective of the diameter of the portion of the cable engaged thereby, and said clamping means including a headed screw passed loosely through the crotch portions of the clamping element, disposed to have its head bear thereon and extending in threaded engagement through the threaded screw hole.

2. A blank substantially rectangular in plan and initially formed from sheet metal, provided at one short end with a dovetail recess and at its other short end with a corresponding shaped projection, one long edge of the blank provided with pair of legs adapted to be bent to form a stop for the bore of the finished article, said blank pro vided with a longitudinally extending corrugation and between the corrugation and the other long side with a pair of transversely extending slots and a screw hole located between the slots. 3. A one-piece blank for forming a cable connector substantially rectangular in plan and formed of sheet metal, said blank provided with a longitudinally extending corrugation and between the corrugation and one of th long sides with a pair of transversely extending slots, the portion of the metal between the slots forming :an embossment extending transversely of the blank and for the most part offset from the plane containing the balance of the blank, merging at its inner end into the corrugation and at its outer end into said long side, said blank except for its embossment being initially fiat and said embossment provided with a threaded screw hole.

4. The blank defined in claim 3 in which the portion of the embossment containing the screw hole is a short internally threaded tube whose axis extends at an obtuse angle to the plane of the blank and is internally threaded to provide a long bearing for a screw.

5. A connector including a tubular member having a pair of circumferentially spaced-apart slots, a clamping member of inverted U-form having a crotch and two legs extending from the crotch and passing through the slots, each leg being shiftable relative to the crotch along the bends formed between the crotch and each leg, screw operating means connecting the crotch-and member and providing a line of thrust passing between the slots and substantially through the axis of the member, said slots being each spaced about twenty-two and one-half degrees are distance from said line of thrust, each leg formed of two integrally connected parts with the lower parts toedin towards each other and towards said line of thrust and extending through the slots, the lower part of each leg initially forming an angle of about fifteen degrees with the line of thrust.

6. A connector including a tubular member having a pair of circumferentially spaced-apart parallel slots each forming a flat parallel guide surface at its outer side edge, a clamping element of inverted U-form including a crotch and two legs extending from the crotch and inserted in the slots, manually actuated operating means connecting the crotch and member for advancing the clamping element into clamping position and providing a line of thrust passing between the two slots, each leg movable relative to the crotch, the inner portion of the legs which extend into the member being inclined towards each other and to the line of thrust, the maximum distance between the inclined inner portions of the legs being not less than the arc distance measured between the slots, the outer side of each inclined inner leg portion bearing on its associated guide surface and reacting therewith on the advance of the operating means to cause the legs to shift relative to the crotch still further inwardly towards the line of thrust.

7. The connector defined in claim 6 and in which the bend formed between one leg and the crotch is cut away at least at one end to reduce the cross section of material in that bend.

3. The connector defined in claim 6 and in which the clamping element is formed of two separable L-shaped parts, each part including one of the legs and a portion of the crotch with a bolt hole in the crotch portion, the two parts operably designed when separated to facilitate the insertion of each of their legs in its associated slot, and the crotch portions disposed when in overlapping relation to have the two bolt holes in registry to facilitate insertion of the operating means passed therethrough and said opening means passed through said aligned bolt holes.

9. A connector including a tubular member having a bore fashioned to receive therein cables of different diameters, said member provided on one side thereof with a pair of parallel slots, a clamping member of inverted U-form having a crotch portion and two legs extending therefrom and with their inner ends intruded through the slots and into the bore to engage the cable for the time being in the bore at points thereon having an arc distance substantially equal to about forty-five degrees, screw means reacting between the crotch of the clamping member and the tubular member to advance the legs into clamping position and providing a line of thrust passing between the slots and substantially through the axis of the bore, the portion of the member outlining the edges of the slots forming guide surfaces, the guide surfaces each forming an angle of materially less than forty-five degrees with the line of thrust, the inner ends of the legs forming toed-in portions inclined towards each other and to the line of thrust and bearing on the guide surfaces and reacting thereon to cause the toed-in portion to approach the line of thrust as the screw means is advanced.

10. In a device of the class described, the combination of a tubular member having a pair of longitudinally extending parallel and circumferentially spaced-apart slots, a spirally wound cable inserted in the member and having a corrugation with an exposed spiral trough between adjacent turns of the corrugation, a clamping member of inverted U-form and having two legs extending through the slots, a screw reacting between the members, providing a line of thrust extending between the slots and through the axis of the tubular member, the portion of the legs Within the tubular member being inclined towards each other and to the line of thrust, the free cable engaging 10 edges of the legs being for the most part flat for engaging the cable and each edge provided with a projection depending therefrom, said projections being spaced apart lengthwise of the cable and fashioned for engaging in the trough at spaced-apart points thereof and said line of thrust inclined to the axis of the tubular member to cause said projections to bear axially of the cable on the portion of the corrugation in advance of the projections.

GEORGE C. THOMAS J R.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 686,704 Bossert et a1 Nov. 19, 1901 1,644,311 Davis et a1 Oct. 1, 1927 1,770,115 Thomas July 8, 1930 1,316,668 Church July 28, 1931 1,904,409 Church Apr. 18, 1933 2,134,655 Tornblom Oct. 25, 1938

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