US2746510A - Forming dies - Google Patents

Description

May 22, 1956 c. w. PEDERSEN 2,746,510

FORMING DIES Filed June 2, 1955 si Arrow/frs:

Unite States Patent O The invention described rherein may .-be .manufactured Aandusedfby `or for .the Government :of the ,UnitedStates @of .America vfor governmental Apurposes without the ,pay- ,ment of any `royalties ythereon `orttherefor.

:This invention relates to `forming dies and more apar- :ticularly to Iforming: 'dies of .the type .including la i plurality :of separable, adjacent, tforming sections Aassembled faccording `toA a predetermined ,rpattern xIn=the `formation of .cable straps,l;pipe :straps-.or thellike Kit -has been known 'for some Ytime :that a die made from 'preformed ,sections assembled ,sideby.side :has a ftremendous advantage over 'unitary .dies The .term unitary rdies asy used inI this-.disclosuretis defined .as fa combination .of.-rnaleY and femaleportions ofdies whereineach portion is an integral unit. Unitary dies ,are very expensive Where the .f number specimensv of .any one particularfprod- `uct .to tbe eformed .by -.the `unitary `dies tis .relatively lsmall thecost per M,unit speeimenioffthe product adaptedto .be ,formed .by the .unitary dies is iunreasonably hi-gh. This inherent disadvantageloftunitary dies, per Tse, isemphasized where the dies `are `used wtoiorm a work-.piece of ,strip `.stock into avseriesfof: predetermined.adjacent/,curva- 4tures `and :the v.dimensions and `eoniigurations :of teach .zcurvature trepeats frequently. For example, :in shipbuilding v.it is necessary-to create-a-tlarge variety of Astraps .for lsupporting cablespipeslor thelike.y The `variety 'of straps stemsfrom.combinations ,of such varietiesuas the number of pipesor-cablesasupportedby theffstraps, their diameters, `the farrangemenntc. V."Ihroughout -ia .vessel .various combinations of "numberand size.ofparallel runs .offcable `and pipe cometogetherfand. require a 'variety of straps, :the variety. beingfequal. inlnumberto thecombinations, :for supporting the cables, pipes vor-.the like. It is 4a known eXpedient'to'.form-ithesestraps ..outfofl strip z stock :by means l of lforming dies` thatfare assembled tfromasections Y of various vshapes :and -siZeswh-ieh: sections are :pre- 4formed to `correspond to particular'diameters Lof .cable for :pipe lFor "anexarnple .of i this type lof-.die, sreference `is madeto =U. S. yPatent lf3-36,1388.

A disadvantage Iin the use l of 1 the sectional ',dies known to-.the priorart is thabnofprovisionismade:.forzforming straps, Lor the like, whiclrfarev vadapted to `secure .the lsmallestand largest cable;and/or pipevsidel-by-side. `Another marked disadvantage iswthat moreftirne4 is required Yin assembling and xsd-isassembling `.the sections :of :dies known to the prior artsince each-sectionis not symmetrical.

This invention ,marks a departure .from lthe `prior art p `byfprovidingva ldie adaptedrtobewassembled'in'a tpower .press from a plurality fof sections. Furthermore 'the .process of assembling the-fdierrequires tninimum attaining 4and a `minimum'of Asetup time as 4'compared to 'similar idevicesrknown'to:theprior art, This invention is ycharac- .terized by a marked :degree :of lversatility in operation. YAn objectl of .this invention'v is 'toiprovide 1a: forming'die. Ak further yobject .is to provide sa :forming `d`,die of a pluralityof separableusections.

,. pieeebetween the sections.

2,746,516 Patented May ,22, 1 95.6

ICC

A .further `object .'-is `to `jprovide Va .forming .die of a pluralityof separable sections -andindent-spaces.

.fA `further -object yis to provide a :forming -die nf .a plurality `of .sections ithat .can ,-be selectively assembled fin any combination of `sizes of v.adjacent sections.

A -furtherfobject 'is to provide Va sectional-formingtdic for straps or 'the like.

A further object is to provide a sectional formingfdie for forming :straps which are `,adapted .to secure anyncom- =binatonof sizes tof `adjacent cables and/or pipesr'the flike. t

,Other objects `and ,many Aof .the -attendant .advantages :of .this .invention will .be .readily appi-"eeiated fas the .-sarne :becomes .better understood .by ireferenee .to .-the following .detailed description vwhen considered in connection `with :the yaccorrmanying y drawings wherein:

fig. l` is a :fragmentary view `of the .-assembledtdie in ;a power press,l and lrig. 2 is` ajpictorial View ,oione :upperdie section,one .flowerfdie seetiornand one'ndent spacer.inoperative-rela- .tionship {Theembodirnent'of `the formingrof the invention=dis closed'in Figs, l .and Y2 tisfdesignedfor use-in 'a power .press ,havingararn a fragment'of whichis .shown at :lf2 :and `aubed .a .fragment of .which isfshownzat 114. Afferm- -ingdie 16 `mounted -in the ram :12 .and the bed -l4-of :the ,power press -is shown iin foperative ,relationship fwith :a worlq-piece -iormed tinto arable strap '.bythe Adie 16. ,The `workpiece 18 ihaving i been formed into a cableV strap fis .adapted lto support .-a frelativelyklargezcable :and .-a r'pair of.,smaller.size Fcablesof equaldiameter. The 'forming -die lrincludesran `upper forming dieportion or maledie port-ion v22 and a lower fforming die portionr24 @and `adapted tofmate with fthe maledie lportion 22. -Eaeh\of the die portions 22 and .24 is an @assembly :of a :plurality A,of separable, similar sections :such as 26, :28 and 32 vmountedtin thezrarn=12 of thetfpower press, notshown,

`andfa :correspondinggpluraiity ,'ofesections 84, `36 .and P33 Mmountedon the bed 14 of .the poweripress. `Theloa/.er :forming die `.portion .124 :is sstationary v.while `:.thefupper ,formingdie `portion 22, -secured :in vthe ,ram 12 of the .powerpressyis reciprocatedtintoandvout ofrmating rela- .tionship with vvthe lower fdie 4portion 24. .Indent : spacers 42, 44, V46, :and 48 .areneludedfbetween teach pairrof sections ,ofi theJ lowerzflorminjgA` die portion .24.

.-.ln,.Fig. 2 one=sectiont52- designedfor'use as part ofthe .uppenforming die-22, a corresponding section. 54designed 4`for use ias partof the lower formingdie.\2'4, 'plus Aione indent. spacerv 56 are shown :in operative `relationship :but removetbfromtthe power press-and not including y"awoi'k- The section 52 of fthe lupper .forming die-has uniform thicknessalongthezwidthfthereof. The top-.ofthe-section 52'terminatesrina dovetail rSS. he v4dovetail SSof thesection 52 is adapted tofslidably engage .within yat continuous dovetailsslot "or channel in f the "ram :12. .Thelower partof theasection NSlis-substantially rec- ;tangular .in .cross section 'terminating in a semicirculal.' workjngsurfaceof radius R. -Theithicknessfof thezsection "52 is equal to 2R. The width of the section 52 whichzis -,equalto .the width ,of section Skis/determined by the width of the stock .used-.for workpiece '18.

The .thickness of=the sectionj54-is reducedffromsa thickness equal Vto that of the :section 52 by .beingrrecessed `equally at 62 and 64. vThe section `52 isiorrned witha fpairfof aligning openings 66 and 68 on one side anda pairof `corresponding aligning studs only one of which is :shown atf72 in Fig. 1. Thealigning openings 66 audLS andthe-aligningfstuds72facilitate the rapid assembly of 3 the lower forming die portion 24 of Fig. 1 are assembled, the indent spacers 42, 44, 46, and 48 slide into the channel defined by the recesses in the adjacent sections of the lower die portion 24.

The indent spacers such as 56 of Fig. 2 are substantially rectangular in cross section terminating in a semicircular working surface 76. All of the indent spacers are formed to have the same width and consequently the same radius of working surface. the workpiece 18 as at 82 and 84 to permit the-strap to properly separately support each of the cables, pipes, or the like.

The procedure to be followed in designing the separate sections 52 and 54 of the upper and lower die portions 22 and 24, respectively, involve first selecting each size of bar stock having a thickness which is equal to the diameter of the cable, pipe, or the like to be supported by the corresponding portion of the strap formed by the die including these sections. The dovetail 58 on the section 52 is of a uniform size which is prescribed for each of the sections adapted to be included in the upper forming die portion 22 for use in a particular power press. The sections 52 and 54 are positioned in Fig. 2 in the same spaced relationship they occupy when mounted in a power press with the ram 12 at the lower limit of its stroke. The spread G between the ram 12 and the bed 14 when the ram 12 is at the lower limit of its stroke defines the distance between the upper surface of the working portion of the section 52 and the bottom surface of the section 54. The depth of the recesses at 62 and at 64 are equal to each other and to the depth of the recesses vin the other sections. The depth of each recess is half the thickness of the indent spaces. The thickness of indent spaces 56 is based on a compromise between strength of the spaces on the one hand and well-defined indents on the other hand. For example if the indent spacer 56 were made too thin its effective life would be very short, whereas if it were too thick it could not define an indent unless the cables were separated. Considerable success has been achieved in making the indent spacers 3A6 of an inch thick when using stock %2 of an inch thick for the straps. Let it be assumed for the purposes of the immediate discussion that the thickness of the stock used in forming the straps is 3/32 of an inch thick. The dimension A therefore represents the summation of the radius R of the cable for which the strap is being formed plus the .thickness of the stock which is %2 of an inch plus the radius of the working surface 76 of the indent spacer 56 which is likewise 1%,2 of an inch. The base of the triangle of'which A is the hypotenuse is equal to R since it is equal to half the thickness of the upper section 52. By means ofthe Pythagorean Theorem the magnitude of C isv readily determined. If the strap is for cable the distance D may be arbitrarily chosen to be 1/32 of an inch less than the diameter of the cable for which the strap is being formed, in order to permit the strap to clamp the cable. The distance F is arbitrarily fixed; for one power press for which it has been designed the distance F has been fixed at one inch. Therefore by subtracting the sum of D, C, and F from G the distance represented by E is readily determined. Once the distance defined by E is determined sufficient information is available for forming the indent spacer 56.

To determine the height of the lower section 54 a corresponding series of computations are resorted to as has been described in connection with the computations for determination of the dimensions of the indent spacer 56. The top of the section 54 is channeled at 86 thereby providing a pair of opposed rims 88 and 92. The rims 82 and 92 terminate in a semicircular working surface the radiusof which has been chosen based upon compromised considerations similar to those involved in designing the indent spacer 56 at X32 of an inch. The depth of the channel at 86 is derived after the height ofthe section The indent spacers serve to indent 54 is determined by means of computations similar to those outlined in connection with the determination of the dimensions of the indent spacer 56. Though the surface of the channel at 86 is indicated as a flat surface it can take the shape of any tool which is conveniently available. The limitation to be kept in mind is that suicient clearance needs to be provided between the working surface of the upper section 52 and the surface 86. Where the only consideration is that of clearance it is evident from an examination of the sections 36 and 38 of the lower forming die 24 that the depth of the channel is not the same. 'Ihe depth of the channel in a section such as 38 corresponding to a cable of larger diameter is deeper than that in the section such as 36. However if this clearance is made uniform it is possible to introduce an additional safety factor for preventing unnecessary damage to the die sections. Y

With the clearance the same and with the ram 12 withdrawn to the upper limit of its stroke a gauging means such as a strip of metal cut to an exact length can be used to check whether the corresponding upper and lower sections of the die portions 22 and 24 and correctly selected. In explanation let it be assumed that several power presses in one immediate vicinity are used for forming cable straps. Let it further be assumed that the spread G is not identical for all of the power presses. Where the dovetail 58 is the same for al1 the machines it is possible to take an upper section 52 that is designed for use with a particular power press having one spread G and assembling it in another power press having a different spread G. It is evident that the section 52 will either be too short if the spread is greater or it will strike the corresponding lowery section 54 if the spread is smaller. Results in either case are clearly undesirable. By making the clearance the same between the working surface of the section 52 and the surface 86 of the channel the section 54 a gauge may be used as a means of checking against such an eventuality.

In operation the sections 52 and 54 are assembled in the ram 12 and the bed 14 of the power press according to the desired design of cable strap. Block 94 having aligning pins and aligning openings similar to those at 66, 68, and 72 is engaged with the stop, not shown, secured to the bed 14 of the power press. Subsequently the sections 34, 36 and 38 are sequentially positioned on the bed 14. And end block 96 corresponding to the end block 94 is the last element included in the lower die portion 24 to be assembled on the bed 14 of the power press. All of the elements are clamped against the previously mentioned stop, not shown, by means conventionally associated with power presses for like purposes. The upper die portion 22 is then assembled by first inserting the end block 98 into the dovetailed channel 102 extending transversely of the ram. The end block 98 bears against a stop, not shown, which has been previously aligned in cooperative relationship to the stop on the bed 14, both of which are not shown, and cooperates with the end block 94 to define the attaching ends of the cable strap. The sections 26, 28, and 32 correspond to and are adapted to be brought into operative associationwith the sections 34, 36, and 38. They are readily assembled in the channel 102 of the ram 12. An end block 104 corresponding to the end block 98 constitutes the last element of the upper die portion 22 assembled in the ram 12. A clamping means, not shown, secures the sections included in the upper die portion 22 to the ram 12.

To provide an additional safety factor to insure the proper order of assembly of the several sections included in each of the die portions 22 and 24 a tool, not shown, having a portion which is of substantially the same thickness as that of the indent spacers and having an upwardly projecting portion terminating in a knifelike edge may be used to indicate whether the width of the upper sections correspond to the width of the lower sections of the die. When the tool is inserted in the position normally occupied by the indent spacers its knife edge should align with the abutting surfaces of adjacent upper die sections.

Not all of the indent spacers act on the workpiece 18 during the forming operation. For example, in Fig. 1 the indent spacers 42, 46, and 48 appear to serve no useful purpose. However in practice it has been found that though they do not operate directly on the workpiece 18 they serve as strengthening members preventing damage to the lower die sections.

In order to quickly identify the multiplicity of various sections for the upper die portion 22 and `the lower die portion 24 each section may be stamped, stencilled, or otherwise marked with the diameter of the cable of pipe size for which it is designed. The indent spacers are correspondingly stamped. For example the upper section 54 and the indent spacer as shown' in Fig. 2 would bear the same identification marks. If desired the identification of the particular power press for which the sections have been designed can likewise be stamped on each of the sections. This is particularly advantageous where a large number of power presses located in the same immediate vicinity are used for forming straps as described herein.

Where adjacent sections of the lower die portion 24 are not the same size such as 36 and 38 in Fig. 1, the indent spacer 46 that is used is the one that is designed to `correspond to the section 38 for the larger diameter cable. The reason for this can be appreciated if one pictures what will happen if the indent spacer 44 is used in place of the indent spacer 46. Where it is desired to provide straps that are to be secured to supporting structure through intermediate spacer pads it is only necessary to vary `the height of the end blocks 94, 98, 96 and 104. For

example by` decreasing the height of the end block 98 it is possible to secure the corresponding end of the cable strap formed thereby to associated supporting structure through spacer pads.

Absolutely no guess work or personal judgment is involved in assembling the various elements comprising the die 16. If a chart is provided to the machine operator indicating the sizes of the adjacent pipes and/or cables to be secured by the cable strap the machine operator simply uses the sections of the die having the corresponding markings. The entire assembly or disassembly of the die16 can be accomplished with ease in a few minutes. `Checking by means of the two gauging tools previously described need take no longer than ten `seconds. One of the salient advantages of this die arrangement lies in its versatility. There is substantially no limitation upon the sizes of immediatelyadjacent sections of the die. A very largesection lof the die can be assembled immediately adjacent to a very small section of the die for clamping a very large cable immediately adjacent to a very small cable. Other advantages of this die over similar devices known to theprior art lies in the fact that the sections of the die as described herein may be readily mass produced, thereby reaping all the advantages' of low cost, accuracy, availability, etc.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

" I claim:

1. A forming die comprising a male die portion and a mating female die portion, said male portion including a plurality of forming sections each terminating in an arcuate forming surface, whereby any combination of sizes of adjacent sections may be arranged in said male die portion, said female die portion including a` corresponding plurality of sections, each female die portion including a pair of rims at the opposed margins thereof, said rims being rounded and serving as forming surfaces, each adjacent pair of sections in said female die portion being jointly recessed to dene a channel, an indent spacer terminating at one end in a rounded working surface for each channel,

2. A forming die comprising a male die portion and a mating female die portion, said male die portion including a plurality of contiguous separable forming sections, each of which terminates in an arcuate forming surface, the forming sections of said male die portion are adapted to have their combined forming surfaces in discontinuous contact with a workpiece, said female die portion including a corresponding plurality of separable sections, each section of said female die portion being formed with a pair of opposed rounded rims defining spaced working surfaces, the transverse dimension of each section of said female die portion at said rims being smaller than the transverse dimension of the corresponding section of the male die whereby adjacent sections of said female die define a channel therebetween, an indent spacer having a rounded edge in each channel, each indent spacer adapted for indenting a workpiece and also strengthening the rims of the sections of the female die portion whereby the die may include any combination of sizes of adjacent sections.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain Aug. 30,

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