US1993295A - Method of producing terminals - Google Patents

Description

March 5, 1935. w CUMMINS 1,993,295

METHOD OF PRODUCING TERMINALS Filed July 14, 1932 2 Shets-Sheet 1 1'74 1/! 2762A F76 34 4A INVENTOR; NORMAN W CUMMINS BY X A TTORNEY.

Patented Mar. 5, 1935 UNITED STATES- PATENT] OFFICE.

10 Claims.

. uThis invention relates to a method for forming terminals or lugs and the like, suchas are attached to the ends of electric cables or wires to expedite and insure good electrical contacts. These terminals are of unitary structure, having a .wire'receivingl end designated as the shank and "aflattened endxrefe'rred to asthe tang.

The principal object is the production of'these widely used" articles from the minimum amount 0f the highest grade material by a reduction in the number of "mechanical operations together with definiteimprovement of. the product and a reduction in the cost of production, and at the same time impr'ovingthe appearance and utility of the product. r

' To accomplish these ends by the preferred method, .it is necessary to'employ'a part of the process for producing cold'upset blanks as disclosed in applicants co-pending application Serial'Number 583,421, filed Dec. 28th,;l931, viz. the sizing of low priced, hot rolled unsized or crude copper wire and'then severing an exact voltime '(exactf'diameter and length) of metal [required for the finished product, concurrently with '25 other'operationsbeing performed by the same cold upsetting or forming machine. 7

To assist in an understanding; ofythis invention, referen'ce is had tothe accompanying drawings which are'incorporated herewith. y

Figures 1 to 3B'inclusive-represent preparation of :the blank, Figs. 1A, 2A and 3A are end views of their associated figures. Figs. 4 to 8 inclusive represent the blanks after certain forming operations, explained hereinafter, all on substantially a full size scale. Fig. 9 is the side elevation of the forming tools or ,instrumentalities while Fig. '10 is a top view of a portion of Fig; 9, also shown .on a fullsize scale. 1

Numeral :10 indicates a'section taken from an indeterminate length of hot rolled unsized stock referred to hereinafter'as crude stock which is to be forced through a sizing die by a specially constructed heavy duty feed mechanism substituted for-the standard relatively light feed equip- ,ment, .prior to the regular severing operation and thereby make possible the production .of uniform socketed terminals, directly from crude stock in place of relatively expensive sized stock and incidently effect a pronounced saving in money as well asenabling the producer to entirely omit the usual individually performed conversion 'step and at the same timeretain the function and resultof that step, which is accomplished by the special feed mechanism, operating in in clamp 15; that the body portion 14a,'.Fig. 3 or connection with an extruding or drawing die,

lodged in the" same upsetting machine which forms the terminals. '7 V 1 Numeral 11 indicates the sized stock, whi1e12 is to indicate the tapering annular section ef fected by the die while the crude stock is in the .5 process of being converted into sized stock. g

The sized stock is severed along the line 2-2 as mentioned supraand is carried over to another die in the same machine'forupsetting as indicated in cross sectional View Fig. 2." A sec- 10 ,ond similar operation produces the-blank shown in cross section by Fig. 3. Fig. 3B is a cross section of a shorter blank being put-through the same steps. 7 a g Toproduce theseblanks uniformly without excessively damaging the'tools, it is'necessary to have the exact quantity of material-1n develop? ing thisprocess applicants first efforts to-produce these terminals from hot wire were not; successful, owing to the very short life of the tools,:especially in producing'the-blank shown in 33 as well as pronounced intolerable irregularities in length of the'socket, all due to the variable volume of metal encountered in the use of raw stock.

Further, uniformity of product is desirable if not necessary to procure trade acceptance. However, certain forms of terminals can be produced directly from crude stock. f

q A supply of blanks as shown in Figs. 3-, 3A or 3B, are. disposed in'a conventional hopper and are automatically picked ,up by a feed mecha-' nism, a member of which telescopes with socket 14 which is passed to theforming dies shown in Figs. 9 and 10 where it is vertically lodged inrthe receiving clamp 15, shown by the dotted'circle, 3.5 which is established by semi-circles 15a-16 when the ram or hammer 17 is approaching the closed position as shown in Figs. 9 andlOand is proceeding for the forming operation which is completed when theface 18 of ram'l'l is positioned substantially as, shown with reference to face 19 of stationary die 20, which is equipped with a slide 21, also shown in the position it is forced to co- 'cupy'at the closed position, however, as ram 1'? withdraws, slide 21 which is responsive to spring 22, tends to hold it in normal open position indicated by dotted lines 23-24. I

It ,will be perceived that as ram 1'7 makes its closing stroke with a blank yieldingly supported 5 0 313, will be swaged into the form 25 shown in Figs. Hand 10 partially in full lineand partially in dotted lines which constitute the tang of the terminal.

'At. the beginning of this swaging process, vv

soon as the blank is caught between the faces of clamp 15 the carrier arm of the feed mechanism, not shown, is withdrawn. As the swaging operation progresses the shank portion 14B which is slidably supported between faces of 15, due to displacement of metal and guiding tapered surface 26 of the die, the shank is affected and moves up and beyond the top surface of said clamp, as shown in Fig. 9, the blank having been originally placed in the clamp with the top surface of shank substantially even with top surface 1-7a of ram 17.

of its spring 22-expels the formed terminal 25.

Prior to this expulsion, punch 27 which is sli'd ably mounted in-die 20, as indicated in Fig.9, is driven by cooperating mechanism'in the direction of the arrow into die 28 mounted inlrami'l l :and'

with which it registers and thereby removes a slug which forms the'eye-hole The slug falls over into cavity 29 and gravitats through hole '30; Rod 17c is'operated' by-acam or crank of the upsetting machine to prevent stock from flowing into die 28 duringswaging. It is withdrawn to permit function of the eye-holding mechanism.

Toeliminate a separate-operation the forming face of die 20 is concave along the dotted line 20a, while the forming face of insert 17b of ram 1-7 is convexed along thedotted line 17 This is also formed with opening28 to provide the "die for co-operating with punch 27. Forming faces of ram 17 in die 20 can be made flat in which case the terminal could be formed accordingly and as shown in 'Figs. 4 and 5. The 'cross sectional view of the terminal as shown in Fig.6 is taken along the line 6 6 ofFig. 4 which 'hasbeeri formed with concavo-convex surfaces. 'Flg. dis. a' linear cross sectional viewof Fig. -4 when {formed with the fiat'ram or-die while Fig. 4a is anend elevation of Fig. 4.

A'similar constructed-set of instrumentalities asshown in Figs. 9 and lowith fiat forming faces are employed to swage the blanks shown in 3b 'in'toaterminal shown in'Figs. 7 -and8, the latter being aside elevation of the former.

Attention is I directed tothe fact that blank shown in Fig. 3, used for forming'the terminal -ill'u strated" in Figs.-4- 4a and5, is employed where an abnormally large conta'ct surface is desirable such as a ground or mass" connection for conveying high amperage cur-rent incident "to starting motor-equipment as employed on present day internal combustion engines. Blank 3b is formed-with adeep "socketresembling-a cartridge shell in order that there will be a-much less quantity of stock to be'swage'd, which will result in the-terminalsshown inFigsL'l and 8 and which are used for installation where-they engage-metal -'of"relatively high current carrying capacity as contrasted with the ground terminal 'which is "usually installed in contact with ferrous metals.

Fromthese operations the quantity of predeterniined-metal in blanks 3 and 31) result in terminals withtangs substantially as'shown in their companion figures withouttrimming which-contributes =to accomplishing the objects I of this invention. Although it is preferred topermit'the -cylindrical stock constituting thetang todevelop a normal'configura'tion from'the swaging operation for'the finished product,'it is obvious that trimming or subsequent shaping can be utilized to fashion the tang to many practical forms, one of which is indicated by the dotted linesuperimposed on Fig. 4 and then forming the tang into a cylindrical hollow or arched form as indicated by an end elevational View in Fig. 4B. Cylindrical hollow or concave forms are particularly useful for efiecting secure connections, as upon riveting or bolting these tangs to a companion member, closer and more enduring contacts are procured than if they had been left fiat. Tangs made with the latter form, even under expert installation, are frequently found tohave reverseIyFcurled or separated at the remote edges, which result in troublesome contacts.

Modifications, extensions, eliminations and combinations can be indulged without departing from the spirit of this invention, therefore I wish toibe limited only by the accompanying claims.

I claim:

1. A methodfor producing an integral terminal fromiapredetermined volume of cylindrical solid cold copper stock which consists of extruding a 20 portion of la'iblank so (as :to have asocket inone :end of said stock,slidably supporting saidstock by one end of said blank in suitable instrumentalities, while swaging the closed end of said:blank by said instrumentalities intoa tang.

2. A method of producing an integral terminal from a length of solid .cold copper stock which consists of upsetting and piercing said stock to 'form a blank extruding said' blank to form :a socket inone end of saidblank, whilemaintain- :ing said diameter throughout the length ofth'e socketed portion of said blank thenswaging the closed end of said blankinto a tang. I

3. A method of producinganin'tegral terminal from a length of cylindrical solid cold copper stock of substantially uniform diameter which consists -of extruding said length of cylindrical stock to form a socket inone end of said stock, by exerting pressure longitudinally thereon while maintaining ther first established inside diam- 'eter-unchanged and maintaining said diameter throughoutthe lengthof the socketedportion'of said stock then swaging thecl'osed end' of said stock into a-tang. V V

4. A-method for-producing'an integral terminal from a predetermined volume of cylindrical solid cold copper stock of substantiallyunifo'rm diameter which consists of lengthwise flowing and thereby forming a socket without changing the inside diameterin one end, b'y exerting pressure longitudinally thereon, of said stock while maintaining said outside diameter throughout its length-then swaging the closed endof said stock into a tang. '5. Ameth'od of procuring-an integral terminal from a length of cylindrical solid cold copper stock of substantially uniform diameter which consists of upsetting and piercing said stock to form a blank extruding said blank to form a socket,having a depth in excess of twice its'diameter, in oneend of said blank, while maintaining said outside diameter throughout the length-of the socketed portion of said blank then swaglng theclosed end of said blank into a tang.

6. 'A' method of producing an integral terminal from a section, of cylindrical solid cold copper stock of a given diameter to form a blank, which consists of extruding said blank so as to-form a socket at one end of said stock without changing the diameter of said stock, then slidably supporting said blank thus formed while swaging the closedend-of said blank into a tangand subsequently-piercing an eyepinxsaid tang while still being slidablysupported.

'7. The method of producing an integral terminal from a length of solid unheated copper stock comprising the following steps: Severing a length from a supply rod to form a blank, simultaneously piercing one end and upsetting said blank throughout the length of same to a given uniform diameter to form a pierced cylindrical blank, then extruding said blank without materially changing said diameter to produce a socket in said end, said socket having a depth in excess of twice its diameter, swaging the closed end of said blank and a portion of the socket to form a tang.

8. The method of making copper terminals which comprises the following steps: Extruding metal into the form of a solid cold copper rod, cutting a section from said rod to form a blank, and subsequently causing a portion of the unheated metal of the blank to flow longitudinally of the axis of the blank to form a socket at one end without changing the diameter of said blank by exerting pressure longitudinally thereon, then swaging the closed end of said blank into a tang. 9. A method of producing an integral terminal from a length of cylindrical solid cold copper stock of substantially uniform diameter which consists of extruding said length of cylindrical stock to form a socket in one end of said stock, while maintaining said diameter throughout its length, by exerting pressure longitudinally thereon, then swaging the closed end of said stock into a tang.

10. A method for producing an integral terminal from a predetermined volume of cylindrical solid cold copper stock of substantially uniform diameter which consists of lengthwise flowing and thereby forming a socket in one end of said stock while maintaining said diameter throughout its length, by exerting pressure longitudinally thereon, then swaging the closed end of said stock into a tang. I

NORMAN W. CUMMINS.

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