US2497568A - Electrical contact device - Google Patents

Description

Feb. 14, 1950 l R. s. THACKER 2,497,568

ELECTRICAL CONTACT DEVICE Filed Oct. 16, 1944 297 nl. ,if 'ff atentecl Feb. 14, i950 UNI-T ED `PrT1-E.`."l*-lfl`V OFFICE- `amino'miein;-oou'riflo'rilnnvlon' l RalphSffThackei'-, Windsorlls, Calif. "nmilictio ocfube's, isuiflser'iaiivd. 553,942

' 'Thisinventof basto dvvithfan fltr'calfcentact device and has fpaiticular `freiee'ncetoa socket 4for a pin 1`type fco'ntact fdevi'ce.' {Ageneral object of theV invention lis to prov-ide fan inexpensive, simple and lhighlyfeioie'nt Contactv device particularly'iuseful onistrandedfcable. y

A' "Electrical Contact devices ithe' natur o'ts'ockets have been made'invariousinanners. "l-Iowever, the -usual fs'ocliet'foi receiving alpinmeniber involves aV lengitudin'allys'plit contact sleeve; lione end ofwhich is 'operi' t6 rfcveth L'invvl'iil the other end is joinedi-t the' lead line-'iorifvvire 'Such split sleeve type*socketsf'establish-limite'dcoritact With the pin and!Y in"nr'actoegftliereisa sbstantial voltage' drop" 'or yelectrical loss-A across" suchy connection.

-It' is a -general "Object of f tlisiinlention to Spiro# vide a 'socket'-type eonnectorfin olvingfgenerally, a; plurality A'of' 'free or floatinglfcontactfseginerits for 'engagingr the 15in; 'each 4of 'whichis f-r'ee toes-k' tablish alseparate and-most'ffective contactwith the'prin. l

- Another*generalf'bjct offthe Vinventioniris Cto provide an lassembly ofi the' engaging-*Segments such-asV I have herinab'vef referred1 to' with means whereby the segments are yieldingly urgedi'nto effective fengagement With' 'a pin A'Jar-rar'x'geel inlthe device. fInl accordance with: 'Sniy Tinventionthe several segments Fare elongate V"men'ibers' f connect-l ed 'directly v'vith-ftlle"'e'rn'is'f'of.y thelfst'ranclsfofe-a cable. Springs rsurround the'ass'ernblyl ofis'egments bear-ing oneachfoneto urgelitinwardly intobearingengagement Withthe pin.

Another object' lof my 'i'nv'ention"is-'to provide a socket 1 contact device f-of 'thelgener al character hereinabove referred rto'vinffwnich the-fseg'ments are carriedin'a -simple'sleeve Wliichvservesltorec'eive the Send' portionofithe insulationon -afc'able` or' line 'connected' to the'device 'i'ormi'n'gfwitl'ithe cable' a complete'f'operati-ve 'struoturewhicli may* belused without iamplincationfor ar-ou-i'cl which insulating materialfcanf be re'ad'ilylfformed for molded to form a'carrierorbdy.

Another ob'ject'f of 'the fpresentinvention iscto provide va contact devi'celfofltheigeneral character l the material." of the stra'ndsi :byI fbeing formed around thestrands through theapplicationfof eX-v ternal pressure. l

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- 125 ieferlredft'o'` in xavhichlthe- 'individualicontact'mem- HThe various "objects landffeatures fofilmynvention Willbe 'ifully-funderstood yfrom the following' y 2 detaileddescription-Riot:a Ltypioal "preferred Cform andiapplicatonfof 'the invention throughout which `description'- reference islm'aderto the'accompanyingf-'drawingsf in' which 'Fig.-1 is a topor'plan view-offanlelectrical contact device 'orf plug embodying the*v present invention and `showing -it a'ssernbl'edi-on orinfcontact vvith- -a- .pair oielectrical cables. Fig-'"2" is lalongia tudinal detailed sectionalview of thefstructure of i the' present 'i -inventionp'fbeing a View i taken as indicated by line 2-'2"onFg'. I1. "Figlffisfan'fenlarged View of a part of the structure being-11a longitudinal'lsectional view of thecontact'parts shown applied fover the ends :of f the .1 strands: or a' cable -iandishovvingl'fthe 'retainingsleve vl`around the'Contactparts.l A Fig'L 4' is a.e transverse sectional viewtaken asindicated?by-linedkonllig 3. l Fig. Slis aitransverse fsectional 'viewi takenfas indicated by 1ine-5;-5 ioniFig.-V :1, :andiFig: 6 is klan I enlarged detailed. sectionalvi'ew @off 'foneof Athe;:segmentsv taken @substantiallyr:asfiindioated :by line J Ii-L-l fon Fig; 3;."-Sho wingit,l'apartf'from z .the f other f elements ofthefconstructicn.

The' 1 structure f'provided* by my @present -inven. tionflis f'appli'cable; Y generally-'nto socketsfor A"receivingielectrical'connectors of ithe type. vFlor eXample,'it maybeusedutoiadvantage'in a construction'lsuitable' forl receiving anelec'trical Aconnector-ici :.thefgeneral type :or rfcrm" which is1 set lforth my -companion'-:applicatiom entitled Electrical lconnectorff filed i `on Aeven Adate herewith; SeialzNo; 558,94L4L4 v11n the :present-disclosme II 'set Y forth `a lsimple embodiment-:ofthe invention Wherein'ztl'iere :are two. units of fthe, invention: incorporated; in: a single-structure lIto, handle a vpair ofvpinficontacts. -f'nipra'ctice ardevice may involve but one'-r unit f of 'r the invention: ior it vmayf involve nianyfunitsv and these :may/be `alike or they I.may beni: different-.sizesor shapes. The' construction that Ilz-:have provided may-be used-"ineach of the units'v` of '.tlie'f construction Aand, :therefore it is'fto be understood :that fthe `.following fde'scri'ptionicof one of l the ,.1 units may 'apply' equallywwell to' Athe erlly', a' contact"partfor-segment I'B on or conn'ection with eachzstrand of the cable'ywhich cena y tact-parts are such-fas toiform'a tubularassenibly fforlthe reception fof aiipinftypelelectricalzcontact;

v means ffl 3 'ivyieldinglyf furgingthe contactcparts2in--` The construction that I have provided involves;` gen- When a standard cable C, which as I have shown in the drawings, is used, I remove the insulation I5 of the cable from the end portion v of the cable so that suitable lengths of the strands 3 Y' the notches 3| therein creates very high pressure S of the cable are exposed. The several strands which are substantially round in cross section,

being an assembly of fine wires, are separatedvv and the contact parts that I have provided are applied thereto.

Each contact part or segment I0 is in the form of a straight tube. In practice I prefer to use simple round tubing of a size that will slidably receive a strand S` of the cable C and I prefer to form the tubes of a good electrical conducting material such as copper. In accordance with my invention I apply external pressure to the tube while it is on the end of the strand S so that the tube is compressed onto the strand and is formed so that it is segmental in cross sectional configuration, as shown in Fig. 6. The desired pressure may be applied by means of a die or forming device which gives the tube the desired shape.

In the preferred form of the invention I apply pressure to the tube so that the several wires of the strand S within the tube are pressed into intimate contact with each other and with the interior o'f the tube and the tube is formed to have a concave inner wall 20, substantially iiat radial side walls 2|, and a convex outer wall 22. In practice I may apply sucient pressure so that the wires of the strand in contact with the interior of the tube are flattened against the tube and the several wires are brought into contact with one another so that they are substantially polygonal or hexagonal in cross sectional configuration. 1 I form the inner wall 2| of the contact to have a radius that will conform to that of the pin to be used with the device, and I form the outer wall 22 so it is substantially concentric with the inner wall. The circumferential extent of each contact part is governed by the number vof strands and corresponding contact parts employed in the construction. For instance, where I have employed a cable with eight strands, as illustrated in Fig. 4, each contact device extends around through an angle of about 45 degrees.-

In practice I proportion the several contact devices so that they assemble into an annular body such as is shown in Fig. 4 which body forms a pin receivingv opening 25 somewhat smaller than the pin to be inserted in the device when the adjacent` contact parts are in contact with each other. In practice I prefer to suitably dress the forward inner cover of each contact part to facilitate insertion of a 'pin into the assembly.

The means I3 provided for yieldingiy urging the contact parts I 0 inwardly involves a plurality of annular spring elements surrounding the assembly of contact parts. Each contact part is provided in its outer wall at suitable points along its length with indentations or notches 3|, and the notches of the several contact parts register forming annular channels or grooves around the assembly of contact parts to receive or to accommodate the spring members 3|). In

the preferred form each spring member 3U is a helical spring arranged in a loop with its ends joined together forming what is commonly termed a garter spring. In the preferred construction the springs 30 and the notches 3| are proportioned so that the spring seat in the notches and do not project radially outward beyond the outer walls 22 of the contact parts. In some cases the springs may be merely applied around theassembly without :being received into the contact parts.

The application of force or pressure to the exterior or outer part of each contact part to form or compressive force at the points where the notches occur and, in effect, establishes a crimped condition in the strands or between the strands and the contact tubes positively preventing disy placement of the contact tubes from the strands.

The sleeve II is somewhat longer than thev contact parts and the parts are arranged so that the assembly of .contact parts is located in the forward end portion of the sleeve. An inwardly projecting radial ange 4U is provided at the forward end of the sleeve to form a stop or limiting shoulder for the forward end of the assembly-of` contact parts. The rear end portion of the sleeve projects inward beyond the assembly of contact parts and beyond the point from which the strands have been bared by removal of insulation I5 so that the end portion of the body of insulation I5 on the cable C is carried within the sleeve. This relationship of parts is clearly illustrated in Fig. 2 of the drawings. The structure formed by the assembly of contact parts and the sleeve II may be used without any additional parts.

The body I2 when used is preferably a molded or cast body of insulating material which encases the sleeve and the end portion of the cable C. In the particular case illustrated there are two cables and the sleeves with their assemblies of contact parts are molded or cast in side by side relation in the body I2. It will be apparent that by'having provided a sleeve around the assembly of contact parts, which sleeve has the inwardly turned flange 4U at its forward end and has engagement over the forward end portion of the insulation I5 on the cable C, it is a very simple operation to mold a rbody of insulating material, such as rubber or the like, around the sleeve and cable without in any way affecting or complicating the other parts of the structure. It will be noted from an examination of Fig. 2 of the drawings that there is a short length of exposed strands S between the end of the insulation I5 and the assembly of contact parts giving slight longitudinal pla;7 or yieldability to the contact' parts.

From the foregoing description it will be ap- The clear-v contact with a pin inserted in the assembly of contact parts. The springs surrounding the assembly of contact parts act on each and every one of. the contact parts normally urging it inwardly and since there is no mechanical tie between the contact parts except through the springs and the cable strands, each contact part is free to center and seat itself on the exterior of the pin or plug to establish a highly efficient seating engagement or electrical contact.

Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art and fall within the scope of the following claims:

Having described my invention, I claim:

l. An electrical socket including a plurality of individual contact parts forming a tubular assembly to receive a pin and each having an opening to receive an electrical conductor, a yieldable element surrounding the assembly of contact parts to yieldably urge each one inwardly, a sleeve surrounding the assembly and said elements, and a body of insulating material surrounding the sleeve.

2. An electrical socket including a plurality of individual contact parts forming a tubular assembly to receive a pin and each being a tube adapted to be connected with an electrical conductor, a yieldable element surrounding the assembly of contact parts to yieldably urge each one inwardly, and a member surrounding and housing the assembly of contact parts.

3. In combination a stranded cable, a tubular contact on each strand of the cable, the contacts being arranged to form an annular socket, means normally yieldably urging the contacts inwardly, a sleeve around the contacts, and a body around the sleeve, the body being formed of insulating material.

4. In combination a stranded cable, a tubular contact on each strand of the cable, the contacts being arranged to form an annular socket, means normally yieldably urging the contacts inwardly, and an insulating member around the contacts, each contact being shaped around the strand contained therein to have a concave inner face.

5. In combination a stranded cable, a tubular contact on each strand of the cable, the contacts being arranged to form an annular socket, means normally yieldably urging the contacts inwardly, a sleeve around the contacts, and a body of insulation around the sleeve, each contact being tight on the strand contained therein and having a concave inner face and substantially flat radial sides and a convex outer face concentric with the inner face, there being notches in the outer faces of the contacts, said means including an annular helical spring carried in the notches.

6. In combination a stranded cable, a tubular contact on each strand of the cable, the contacts being arranged to form an annular socket, means normally yieldably urging the contacts inwardly, a sleeve around the contacts, and a body of insulation around the sleeve, the sleeve having an inwardly extending flange at the forward end of the receptacle formed by the contacts and having an inner end portion projecting beyond the said receptacle and over the cable.

7. In combination a stranded cable including conducting strands and insulation over the strands except at their end portions, a tubular Contact on the end portion of ea-ch strand of the cable, the contacts being arranged to form an annular socket, means normally yieldably urging the contacts inwardly, and an insulating member surrounding the socket formed by the contacts.

8. An electrical socket for use on a stranded cable including a plurality of individual tubular contacts each having a strand of the cable extending into it and all assembled to form a socket, each contact having an inwardly indented portion to grip the strand within it, and a yieldable member surrounding the assembly of contacts and held by the notch portions of the contacts.

RALPH S. TI-IACKER.

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

UNITED STATES PATENTS Number Name Date 1,759,567 Dibner May 20, 1930 1,936,469 Hill Nov. 21, 1933 2,083,379 Hill June 8, 1937 2,265,006 Rubel et al. Dec. 2, 1941 FOREIGN PATENTS Number Country Date 470,611 France June 19, 1914

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