US2869612A - Bending machine to form wire articles containing an offset - Google Patents

Description

Jan. 20, 1959 J. c. BERTRAM Y 2,859,612

BENDING MACHINE TO FORM WIRE ARTICLES CONTAINING AN OFFSET Filed Nov. 1, 1956 3 heets-Sheet 1 lava! MM 4/ v 4 I 35 l "139 i i '39 INVENTOR. Jo /v CIBE/PTRAM 5 BY M ,@u, M, @aayrfieaa,

ATTORNEYS Jan. 20, 1959 J. c. BERTRAM 1 BENDING MACHINE TO FORM WIRE ARTICLES CONTAINING AN OFFSET Filed Nov. 1, 1956 3 Sheets-Sheet 2 WET 4 3a m 75 72 R INVENTOR. J (/OHN C. BER TRAM BY L" .J

a @a, M,MY@%Q fie. 7

ATTORNEYS.

Jan. 20, 1959 J. c. BERTRAM BENDING MACHINE TO FORM WIRE ARTICLES CONTAINING AN OFFSET 3 Sheets-Shrget 3 Filed Nov. 1, 1956 INVENTOR. (/OHN C BER TRAM BY. @424, W, M Y @aa,

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"movement of said first forming tool means United States PatentO BENDING MACHINE T FORM WIRE ARTICLES CONTAINING AN OFFSET John C. Bertram, Mayville, N. Y., assignor to Bertram Wire Products, Inc., Buffalo, N. Y.

Application November 1, 1956, Serial No. 619,854

7 Claims. (Cl. 153-34) 7 to the desired shape by separate bending and/ or offsetting operations. This practice requires multiple handling, increases the likelihood of rejects, and in these and other ways greatly increases the cost of such articles.

Accordingly, it is a primary object of this invention to provide a mechanism for forming, in one operation, wire articles having offset bight portions with compound bends therein.

Another object of this invention is to provide a mechanism which will accomplish the foregoing without stretching and thereby weakening the wire.

A wire forming device constructed in accord with my invention is characterized by the provision of die means having aface portion corresponding to the curvature of the desired bight portion when projected on a base plane, first forming tool means movable toward the face portion of said die to bend a length of wire therearound and initially form such bight portion in that base plane, die parts offset from the base plane, and corresponding to the offset curvature desired in such bight portion including any bend therein, additional forming tool means movable to draw the bight portion of such wire out of its base plane and againstthe die parts while the wire is held against the die means, and means for so moving the additional forming tool means following predetermined The foregoing and other objects, advantages and characterizing features of a wire forming mechanism con structed in accord with my invention will become clearly apparent from the ensuing detailed description of a "presently preferred embodiment thereof, taken together with the accompanying drawings illustratingsuch embodiment wherein likereference numerals represent like parts throughout the various views and:

Fig. 1 is a plan view of a wire forming mechanism constructed in accord with my invention showing the retracted position of the forming tools in full lines and the extended, forming position thereof in broken lines;

Fig. 1A is a fragmentary, somewhat schematic detail view illustrating the operation of one of the forming tools thereof;

,Fig. 1B is a fragmentary, somewhat schematic detail view illustrating the wire holding action between the forming tool of Fig. 1A and the die, being taken about Fig. 3 is a view partly in section and partly in eleva s tion, being taken about on line III-J11 of Fig. 2,

Patented Jan. 2i

Fig. 4 is an elevational view taken about on line 1V-IV of Fig. 1;

Fig. 5 is a plan view of a wire article formed by the mechanism of Figs. 1 through 4;

Fig. 6 is a sectional view thereof taken about on line VI-VI of Fig. 5;

Fig. 7 is a perspective view showing the article of Figs. 5 and 6 incorporated in a guard for a trouble lamp; and

Fig. 8 is a generally diagrammatic, isometric view of the mechanism of Fig. 1.

A wire forming mechanism constructed in accord with my invention is adapted to form wire into any of a wide number and variety of finished products, as will become obvious. For illustrative purposes only, and without thought of limitation, there is shown in Figs. 14 of the accompanying drawing and described hereafter die and forming tool parts designed and arranged in accord with my invention to produce the article illustrated in Figs. 5 and 6 and comprising a horseshoe, generally designated 1, adapted to be secured to a hinge 2 and a vertical rib 3 to comprise therewith the wire guard of, for example, a trouble lamp indicated in broken lines at 5.

it will be seen from Figs. 5, 6, 7 that the horseshoe 1 comprises a length of wire stock bent to form a tapered pair of side leg portions 6 having at one end thereof inwardly and upwardly inclined terminals 7 and joined at their other end by a bight portion bent upwardly out of the plane of side leg portions 6 and comprising upwardly and inwardly curving portions 8 and an interposed compound bend 9.

Hereto fore, when forming the horseshoe 1 it was the practice to initially bend a length of wire to form a bight portion, side leg portions and terminals all lying in a common plane, and then by separateoperations to form the upturned terminals 7 and the offset bight portion and bend 9 therein.

However, with a machine constructed in accord with my invention a length ofwire is formed into the finished shape illustrated in Figs, 57 in a single operation, thereby greatly facilitating the manufacture of such articles and reducing the expense thereof.

In the wire forming device of my invention shown in Figs. 14, there are provided a fixed die and a number of forming too-ls movable relative thereto and coacting therewith in a manner to be described. The die and forming tools are mounted on a conventional wire forming machine of a type known in the art, such as for example the automatic four slide wire forming machine made by the Baird Machine Co. of Stratford, Conn, which in itself is no part of my invention and the details of which are not essential to an understanding of the invention. For these reasons, the machine proper is only suggested in the drawing by ways, slides and a few other parts adjacent the die and forming tools.

Thus, the machine proper will have provided as a part thereof an arm-like extension 11 terminating at its outer end in a generally U-shaped bracket 12 to which the stationary forming tool, hereinafter referred to as the die, is attached by means of a die plate 13, the latter being secured to bracket 12 as by bolts 14 or the like. A block 15 is positioned above plate 13, and the die includes a.

main body part 16 and a bottom plate 17 therebelow, with bottom plate 17 being secured to main body part 16, and 'main body part 16 and block 15 being secured to plate 13, asby bolts or the like indicated. at 18.

The main die body 16 is provided with an enlarged head fitting. into a recess in the bottom of plate 13 and providing overhanging shoulders 20 along the opposite sides of said die body 16. The front face 19 of body part 16 and the side walls 21 thereof beneath shoulders 20 areshaped to provide the plan view outline of bight 3 portion it, 9 and side leg portions 6 as illustrated vin Fig. 5.

In operation, a supply of wire 22 is fed into the machine across the front face 19 of'the die by a conventional wire feeding mechanism, part of which is indicatedyat 23', and the desired, predetermined lengthZZ ;;thereof; is cut off by a conventional wire cutter idzas'it is held a'gainst the die by a front first formingtool unit genelrally desigv nated 24. Front tool 24 comprises ;a pair f opposed jaw parts25 spaced apart a distanceequal to theWi-dth of the bight portion of the article :being formed,.-comprising the maximum width of the die body part :16, each of said parts 25 having generally semicircular grooved front faces 26 adapted to'1engage thegcut wire 22 and urge it against thefront face 19 of die part 16 and then, bendthe same therearound. The inner side faces of said parts 25 areelongat'ed and have a generally horizontal ledge or shelf, portion ,2? adapted to underliethe; side leg portions 6 of the wire and, together with the cooperating overhangingshoulders 26 .of the die body 16, to hold said length of wire in place against the die 16 (Fig; 1B).

Each front forming tool part 25 is provided with a transverse firstdepending flange 28 abutting against the frontwall of a forming tool holder plate 29, and adjacent its rear edge with a second depending flange 3t fitting in a groove in the holder plate 29, thereby securing the forming tool part 25 against lengthwise movement relative to'holder plate 29. Forming tool parts 25 are ,releasablysecured to holder plateZ as by bolts 32 extending through transversely elongated slots 33 in the .tool parts .25, whereby the spacing between the opposed jaws ,ofrtoolgparts 25 can beselectively adjusted.

Holder plate 29 is mounted on a front slide 35, being ;secured ;';theretosas by I a bolt 36 extending through a lengthwiseelongated slot 37 in holder'plate29, to permit selective axial positionaladjustment of the holder plate .relative to its slide. Slide is 's'lidable in-a way 38-and has an upstanding portion 39comprising a bearing for a set screw 40 which bears against a pad plate 41 at the back of holdertplate 2%, whereby set screw 40 can be manipulated to axi'ally adjust the position of holder plate 29 in way 38. Plate 29' then is locked in position by the bolt 36 and set screw 40, the latter'being held by a lock nut 45.

'It will be appreciated thatslide 35 isa standard forming slide and is operated in a conventional manner as by a standard cam,-notillustrated. In operation, after a length of wire 22 is fed across the front face 19 of die 'part 16, the front forming tool 24 is moved inwardly in l the direction of the arrow 42, and as it bears against the wire 22 and holds it in placeagainstdie ,lfi the cutter '23 automatically severs the wire to its correct length 22'.

Themovernent of cutter-23 is synchronized with that of tool 24 in any desired manner, as by securing the cutter to holder 29. 7

The front forming tool 24 continues its'rinward movement and bends the wire piece 22 around "thefront' face portion19- of diepart 1 6, as'illustra'ted irrPig. 1A', and then along the sides thereof between the overhanging shoulders 25% on the die and the ledges 27 on the forming tool. However, the front forming tool does not bend the side leg portions 6 against the die in a manner a to taper the same, but leaves them extending straight totthe desired curvature of bight portions8. Also, die

a .UbQdy IGHihas. a.forwardlyhextending..partw44 on. the top center of its front face, which extension has an under surface corresponding to the curvature of bend 9 in the bight portion. Second forming tools comprising a pair 5 of generally L-shaped, bellcrank levers 45 are pivoted on die part 16, one on-each side of extension 44, for movement about a transverse axis relative to die part 16, asby meansof pivotspins 46. .aEach lever 45 includes a relatively long upstanding leg-41 movable in slots formed to in die body 16, die plate ,13 and block 15, and a relatively short leg 48 movable in. slots -in die part 16 and adapted to engage beneath the wire piece 22 at front face 19 and drawitrup against the shoulder surfaces 43 and around extensionc44ton opposite sides thereof to 5 produce the compound bend, offset bight portion 8, 9

illustrated in Figs. 57.

A block 49, undercut to accommodate front tool parts 325, issecurednto the front forming toolz-holder plate 29 zas by bolts vion-the like,"andx-resilient-biasing means such 29 :as :a;p'air; of coil springs "50 are secured atone end to the outer ends of legs 47 of.levers 145 -.and at their other ends .to anchor terminals 51:.secured to block 49Qas by bolts;52. 'jSpringsi50 therebyinormally urge the levers 45 J in a counterclockwise-direction as viewed in Fig. 2, Whereby both legs :thereofareoutof' the path of movement of wire '22 as it is fed into themachine.

:A second forming tool-actuator part53 isslidable in'a groovezin: block- 49, being-adjustably positioned-"therein a as by: acset screw 54 carried ina bearing p1ate'55 on the 30 back of theblock-49. Actuator part 53 vis locked in :i-adjusted position ast by a bolta56 extending through an ..:axially elongated slot-57 therein whereby it is movable awithj thefrom forming tool -24"asa part thereof, being positioned between the front tool parts 25.

' Inopera tion,. the len gth of" wire 22 ;i s-pa r-t ially-bent -around'thefront'face of the fdie'body 16 by 'the'forming tool parts 25 to the-extent necessary to hold the wire rpiece against the die p'art' 16 ,'--'-'whereupon the' actuator I part '53 bears against the legs 47" of-levers 45 and urges them in a clockwise direction as viewed] in Fig." 2 againstthe action of springs 50 causing the legs '48 thereof to swing upwardly and thereby draw the 'previot'lsly'flat bight portion of the wire piece 22' against the under -s urface' 43 of the forward shouldered portions 20 and 45-around the bottom Of thC' extension 44, to provide the "curving offset and compound bending comprising portions '8 and 9.

Thus, the compound bend,three"dimensional form of the article bight portion is produced in one operation, as

50 j distinguished from the multiple operations previously required, by virtue of the above'described arrangement for initially partially bending a length of wire to form side leg portions and a bight portion lying in a common plane and*thenv drawing "th e'bight portion out of the plane ofithe's'ide legs and against: die parts 'producing the compound bend therein asij'forrning; pffthe side legs continues. l r I e forming o le and; ovcrltat sitisldieth .11 1- 'ders' 20' cooperate to receivefjthe fside lg. portions [6' ,of

60 the wire 22, as indicated in 'Fig. 11B, andhold the wire against die body 16 with aidegr'eeof tightness sufficient to produce such bending or the bight but withoutclamping it in a manner such that the wire would be stretched and thereby weakened. Invotherwords, the shoulders 20 and ledges 27 holdthe'wireon opposite sides of the bight portion sufiiciently tightly to enable parts 45 to draw thewire upwardly as .described above; while permitting motion of: the wire relative thereto. to provideflthe'addition'al wire required for such forming-without stretching the wire. This is of extreme significance, becausewire loses its strengthwhen stretched, and; solves the problem of avoiding stretching which heretofore necessitated separate. formin p ra o I v v Then, the side leg po tion are, bent. a ain t th side of die part '16, to providethe tapered form of'the finished article 1, and terminals 7 are bent inwardly, this being accomplished as by means of side forming tools 60 which are carried on slides 61 in Ways 62 in a manner similar to the front forming tools 24, being secured on the slides as by bolts 63 extending through transversely elongated slots 64 in the tools.

Each side tool 60 is provided with a projection 65 extending forwardly of a fiat, obliquely directed portion 66 which latter engages the side leg portions 6 at approximately the juncture thereof with the terminals 7 to hold the same against the sides of die body 16 while the projections 65 bend the terminals 7 inwardly, as illustrated in Fig. l.

Then the inwardly extending terminals 7 are bent upwarrlly out of the plane of side leg portions 6 as by a rear or back forming tool 70 which is secured to a slide 71 in a, way 72 as by a bolt 73 extending through a transversely elongated slot 74 in the tool. Tool 70 preferably includes atits forward end a pair of rollers 75 aligned with terminals 7 and journalled for rotation about substantially horizontalaxes positioned below the plane of side leg portions 6, whereby as back tool 70 is moved inwardly toward the die, rollers 75 engage beneath terminals 7 and bend the same upwardly. Rollers 75 are used because they are not subject to as much wear as for examplea fixed wedge would be.

It will be noted that each of side tools 60 and back 'tool 70 is provided with a recessed or notched formation 60 and 70', respectively, interlocking with corresponding :formations on the slides61 and 71, respectively, to prevent relative axial movement therebetween.

While these various forming steps occur sequentially in the manner described above, it will be appreciated that they occur in very rapid order and comprise but a single operation producing a completely formed article without further handling. This operation is summarized as follows.

At the beginning of each cycle of operation wire stock is fed across the front face 19 of die body part 16 and is cut off as the front forming tool 24 is caused to move in and bend the length of wire 22' therearound. After front forming tool 24 has moved through approximately one-third of its movement, enough to hold the wire 22 sufficiently tightly to permit drawing of the bight portion, the actuator part 53 on front tool 24 bears against levers 45 carried by the die and swings them up to draw the bight portion upwardly against shoulders and extension 43 to produce the offset and compound bend therein, as forming tool 24 continues ,its inward movement. This occupies approximately one-half the total operating time in each cycle, and the front forming tool 24 then holds the partially formed article in position on die 16. Meanwhile side tools 69 have been moving in and they then bend the wire side leg portions against the sides of the die and bend the terminals 7 inwardly while continuing to hold the side leg portions 6 against the die body part 16, this action occupying approximately the succeeding onequarter of each cycle. Meanwhile the back tool 70 has been moving in and it then engages beneath terminals 7 and bends them upwardly during the remainder of the cycle. All of the forming tools then are withdrawn simultaneously and the completed article 1 is removed from the die, with the device automatically continuing this cyclic operation as long as the machine is running.

Thus, my invention fully accomplishes the above objects. While the device specifically disclosed herein uses die and tool parts shaped and arranged to form the illustrated horseshoe 1, it is obvious that other shapes and arrangements can be used to produce articles of different form and that the same is susceptible of other variations, all without departing from the spirit of the invention and the scope of the appended claims.

Having fully disclosed my invention in a presently 6 preferred embodiment thereof, and described its mode of operation, what I claim as new is:

1. In a device for forming a wire article having a portion offset from a plane and formed with a bend therein, first die means having a face portion shaped to provide the plan view curvature of such wire article portion, first forming tool means movable toward said first die means to initially bend a length of wire around said face portion in said plane, second die means positioned on one side of said plane' and shaped to provide the curvature of such bend, third die means positioned on said one side of said plane on opposite sides of said second die means and shaped to provide the desired ofiset curvature on opposite sides of such bend, second formingtool means movable into engagement with such wire on the opposite side of said plane and on opposite sides of said second die means to draw such wire out of said plane and against said second and third die means, and means for so moving said second forming tool means.

2. A device for forming a wire article of generally U-shaped plan view form having opposite side leg portions lying in a common plane, an offset bight portion, and

inturned terminals bent out of said plane, said device comprising, die means having a face portion and opposite side portions shaped to provide the plan view outline of such article, first forming tool means movable toward saidface portion to bend a length of wire therearound and thereby initially form such bight portion and opposite side leg portions in a common plane, die parts extending from said face portion on one side of said plane and shaped to provide the desired offset of such bight portion, second forming tool means movable to engage such initially formed bight portion from the other side of said plane and draw the same against said die parts, third forming tool means movable toward said die side portions for engaging such side leg portions and bending the terminals thereof inwardly, and fourth forming tool means movable toward such inturned terminals to bend the same out of said plane.

3. A device as set forth in claim 2, wherein said die side portions taper from said face portion, with said first forming tool means initially forming such side leg portions in generally parallel relation, and said third forming tool means bending such initially formed side leg portions against said die side portions to provide the desired taper thereof.

4. A device as set forth in claim 2, wherein said fourth tool means comprise roller means journalled about an axis transverse to such side leg portions and offset from said plane.

5. In a device for forming a wire article having an otfset portion with a bend therein, die means having a face portion, means for feeding a length of wire into position adjacent said face portion, forming tool means movable toward said face portion to bend such length of wire therearound and thereby produce a preliminary forming thereof in a common plane, said die means including a part offset from said plane on one side of such length of wire, movable lever means arranged to engage such length of wire on the other side thereof and draw the same out of said plane and against said die part, and means for so moving said lever means following predetermined movement of said forming tool means toward said die means, said forming tool means holding such length of wire against said die means with a degree of tightness enabling such drawing thereof by said lever means without stretching the wire, wherein said lever means comprise a bell crank type of lever having angularly related leg portions, and means movable with said forming tool means for engaging one leg portion and thereby pivoting said lever to cause the other leg portion thereof to engage such wire and draw the same out of said plane against said die part.

6. In a device for forming a wire article having an offset portion with a bend therein,.die means having a me "pardon, "meaas "far regat a a' 1egthfarjwi ajngb Q Qn ad a ent s l? face PQll n: [te mi a d means movable toward said face portion to bendsueh length of wire therearound and thereby produce a preliminary forming therebfina'cofrim'on plane, s'ai'd die means including a part offset fromsaiclplaiie on one side of such length of wire, movable Lever mean'slarranged to engage suehlength of wire on the other sidej thereof and draw the same out of said plane'and againstisaid die part, and means for so moving said levermeans foll'oi'yi11"g predetermined movement of said formingtool nieanstoward said die means, said forming tool means holding "such length of wire against said die means with aidegr e'e of tightness enabling such drawing thereof by said leyerjme'ans Without streteh- .v ing th'ewire 'wlierein saidleyer'means comprise a pair of bell crank typ'e leyerspos'it' 'n'ed on opposite sides of said die part, springr'neans biaslngthe wire engaging legs of saidleverso'nt ofwi'reeiiga'g g position, and means car:-

ried by said fearis for engaging the other legs of said levers and urging the Wire engaging legs "thereof into wireengaging position.

7.;1na device tororming a wirear'ticleliaving an olf- '-'set' intermediate portion with a bend therein and opposite side portions adjacent thereto, die means having a face portion, means for feeding a length of wire into position "adjacent said face portion, forming'tool means movable toward said face'po'rtion to bend such length of wire therea'round and thereby produce a preliminary forming thereof into intermediate andside portions lying in a common plane, said die means including a part offsetfrom said plane -'on o'ne'side of the'intermediate portion of such nd a nst sa' sld'i ei pp s t s deb ermovab e le im a a nged to enga a te P rti n. of u fien h f WWQQILWF .q he s ide ther of. idt whthame v011w? aid12 mm H I I h to offsetsu ch intermediateportion and produce the desired bend therein, andrneansfor 'ng rsaid leyet means following v predetermined H f lsaid forming, to'ol means toward said di e ,s d'f'oi'm l n'i ns holdingthe'oppositeside norttoris'iif-suclh'length o Wire, agairists'aid die'mean's with i M v file 'oft his' p atent UNITED STATES PATENTS 795,916 Jones '..Aug. 1,' .1905 1,432,573 Senft Oct. 17, 1922 1,721,636 'OBrien 1.. July 23, 1929 1.721.810 Carter; .L;. July23, 1929 2,048,459 jMOfiett July'21, 1936 2,497,297 iCourtj Feb. 14, .195!) 2,64051'0 Young June 2, 1953

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