US2600628A - Sheet rolling machine - Google Patents

Description

June 17, 1952 L. w. 'EVANS 2,600,628

SHEET ROLLING MACHINE June 17, 1952 l.. w. EVANS SHEET ROLLING MACHINE Filed Jan. 1'0, 1949 3 Sheets-Sheet 2 www INVENToR. 45m-u m/ EVA/V5 BY June 17, 1952 w. EVANS 2,600,628

SHEET ROLLING MACHINE Filed Jan. l0, 1.949 3 Sheets-Sheet 5 A INVENTOR. Mu/fa wv h/ EVA/v5 Patented June 17, 17952 UNITED STATES PATENT OFFICE SHEET ROLLING MACHINE Llewellyn W. Evans, Rivera, Calif., assigner to Rheem Manufacturing Company, Richmond, Calif., a corporation of California Application January 10, 1949, Serial No. 7 0,030

13 Claims. 1

This invention relates to machines for fabricating sheet metal and has particular reference to mechanisms for shaping initially dat sheets into articles of partial or complete tubular form.

An object of the invention is to provide, in a machine of the character described, cooperative shaping elements capable of providing a continuous uniform curvilinear bend in a sheet of material, which bend extends substantially entirely between the opposite edges of the sheet.

Another object of the invention is to provide, in a machine of the aforementioned class, a combination of form-shaping elements and sheet feeding means in which production of a substantially complete peripheral bend in the sheet is accomplished for the most part by reason of the feeding means engaging and moving the sheet entirely across the Width thereof in the direction of the resulting bend.

A further object of the invention is to provide means in a sheet rolling machine capable of producing parts of partial or complete tubular form Which are uniformly arcuate throughout the extent of their bends thus rendering the parts capable of ideal snug engagement with circularly or arcuately curved fittings such as, in the case of certain tubular articles, head members which may be subsequently attached to the latter articles to provide end closures therefor.

A still further object of the invention is to provide, in a machine of the character described, a group of bend-forming elements capable of ready and relatively proportional adjustment by a simple conditioning operation to produce shaped articles within a comparatively wide range of curve radii.

Yet another object of the invention is to provide, in a mechanism of the character referred to, a group of relatively positionable bend-forming elements capable cf being fixed to define spaced points along a path of bend for the sheet material and operable simultaneously by means common to all of the elements of the group so as to move the latter into properly related positions to define a different path of bend for the material.

It is still another object of the invention to provide, in a machine of the class described provided With a mandrel member about which an initially fiat sheet of material may be shaped to arcuate or cylindrical form, a combined drive and bendforming unit for the sheet material which is associated with the mandrel and which is yieldably movable radially thereof so as to compensate for overall and localized variations in the 2 thickness of the sheet material being passed through the machine without disturbing the bend shaping characteristics of the machine.

A still further object of the invention is the provision of a machine having a mandrel member about which an initially flat sheet of material maybe shaped to arcuate a cylindrical form, and which is adapted to coact with a combined drive and bend-forming unit for the sheet material; the initial setting of the combined drive and bend-forming unit, relative to the mandrel member, being adjustable in order to accommodate materials of different thicknesses.

Still further objects and advantages of the invention will be apparent in the following description and claims considered together with the accompanying drawing, in which:

Figure l is a portional top plan view of the improved sheet rolling machine of my invention, a portion of the View being broken away so as to more clearly show the internal construction.

Figure 2 is a vertical sectional view taken in the plane indicated by the line 2--2 of Figure 1 and showing the relationship of the parts in the production of a bend of minimized radius.

,Y Figure 3 is a View similar to Figure 2 showing the position of the parts in the production of a larger radius bend in the sheet material.

Figure 4 is a front elevational view of one of the positional adjustment screw gear boxes.

Figure 5 is a perspective View of the bend-forming shoe adjustment bar.

Figure 6 is a fragmentary elevation, partly in section, showing a modified form of pressure applying mechanism, and adjustable stop.

Figure 7 is a section taken on line 'I-(l of Figure 6.

The most familiar and generally used machine for forming initially flat sheets of metal or other permanently deformable material into articles having a partially or completely cylindrical form comprises a group of at least three parallel rolls radially spaced with their axial centers arranged in a triangular cross-sectional pattern. Two opposed rolls forming the base of the triangle have their axes fixedly positioned but the third or upper roll is vertically adjustable relative to the fixed rolls so that the periphery of the adjustable roll may be moved to positions overlapping a material feeding path which comprises a plane tangentially intersecting the peripheries of the iixed rolls. Thus a sheet of material passed along the aforesaid feeding path will be caused to pass over one of the xed rolls, under the vertically adjustable roll and thence over the remaining fixed roll, the degree of overlap of the adjustable roll with the feeding path imparting a bending strain to the sheet material sufficient to ex the latter a desired amount beyond its elastic limit so as to form a permanent bend of desired curvature in the material, one, but usually all, of the rolls are power driven in unison so that once the sheet tractionally engages all of the rolls, the sheet will be carried through the roll group and will be given a continuous uniform bend between the leading and trailing edges thereof transversely disposed relative to the direction of sheet movement.

The principal deficiency in the conventional sheet rolling machine is its inability to produce a uniform bend in the sheet material which extends entirely to the opposite edges of the latter or into such proximity thereto that the subsequent operation of joining fittings, such as circular head members in a tubular shell formed of the sheet will not require excessive welding, to ll the ab- "norinallywide peripheral gap between the head members and the shell' in the vicinity of the longitudinal butt thereof, nor subsequent hand bending operations on the shell butt to close the aforesaid gap prior to the welding operation.

4"Such production delays, it is obvious, can serious- `lyV Iimpair plant efficiency and unduly increase production costs.

".lThe limproved sheet rolling machine of my inoperationsrare expedited tothe point wherein I:maximum production speed may be maintained.

11n-the form in which l have chosen to illustratemy invention I provide a supporting frame 6 having endv pillars 'i rising therefrom in which are-formed bearings 8 journalingr the opposite shaft ends 5 of an axially horizontal mandrel roll *9 thus .maintained in constantly fixed relation with the supporting frame. i Situated laterally of a vertical plane intersecting the axis of the inan- Hdrei-rollv 9 I provide horizontal stub shafts II ixedlyy supported. in axialalignment in the sup- -porting frame 'I and upon which are pivotally mounted rocker arms I2 extending radially of Vthe shafts and passing under and oppositely beyond the mandrel roll 9 to terminate in integral lever arm extensions I3. "Formed in the combined rocker and lever arms and substantially coinciding with `the aforesaid vertical plane passing .through the mandrel roll axis, are journals Hl which form bearings for the stub shaft end `porytions 'IS of amaterial drive roll I'I axially paralf'le'ling .the mandrel roll and adapted', upon move- -mentof the rocker arms I2, to be caused to ap- V-proa'ch or recede from the periphery of the manv drel roll.

. Preferably carried on the lever extension' I3 of the rocker arm I2 is an apron I8 whose lupper surface I9 is tangential with the periphery of the 'drive roll Il to define a linear feeding path for thesh'eet material 2l which is thus introduced tangentially between the mandrel and drive rolls 9 and Il. As here shown,l the shaft portions 5 and I of the mandrel and drive rolls 9 and I'I respectively are each provided with gears- 22 rela- `tively intermeshed to cause synchronousV rotation ofrtherolls, vand one of the shafts 'is'connected tto Vbe power driven by suitable means whichyalthough not shown,` is commonly familiartoA the rof.

average person skilled in the art. Also connected to a distal portion of each lever arm I3 by a pivot pin 23, is the piston rod 24 of an actuating cylinder E5, preferably powered pneumatically and provided at its lower end with a pivotal connection to the supporting frame as shown by the pivot pin 2l. iresence of air under pressure in the cylinder 2&5 causes the rolls to forcibly urge toward each other and to thereby squeeze the sheet material passed therebetween with sufficient pressure to eifect movement of the material along the ig path by the tractive effort thereon of the power-driven rolls. Depending upon the surface characteristics of the material and in the force necessary to 'eect the subsequent bend in the sheet, the operating pressure of the cylinder 26 may be increased or decreased as desired.

Means is provided for defiecting the sheet material passed between the rolls t and i7 from the aforesaid linear feeding path in sufficient degree beyond the elastic limit of the sheet material that the sheet will thereafter permanently retain a form of the desired curvature ranging from only a slight bend to a complete curl wherein the edges of the sheet traversing the direction of bend will. be brought together in substantially snug abutting relationship. Connected at its ends to the respective rocker arms I2 and extending above the pivot shaft II in parallel relation to the rolls is a rigid base bar 2S Yhaving a seating groove 2S of substantially semi-circular cross-sectional form extending along the upper surface thereof and provided with a longitudinal lip portion SI of wedge-shaped cross-sectional form extending into the gullet defined by the relatively confronting portions of the roll peripheries so as to place the lip desirably close to the pressure point where the rolls tractionally engage the sheet material. rlhis construction is provided to afford maximum strength of support for the bend-forming elements to be immediately described. Mounted byscrews 32, or in any other suitable manner on the longitudinal edge portion of the base bar 2B, is a housing 33 havinga recess ifl which opens along the longitudinal side of the housing facing the rolls 9 and I 'i to form a gap denedby the upper surface of the base bar 28 and by a superposed lip surface 3S of the housing 33. vThe recess'sfi is further'formed witha longitudinally extending arcuate surface portion 37 concentric with the axis of the semi-circular groove 29. Disposed for'slidable movement on each other and on the upper surface of the base bar Z5 is a plurality of elongated'shoes 38 composed of wear-resistantv metal and arranged in superposed relation to snugly occupy the gap between the said upper surface of the base bar and the lip vsurface 36 of the housing 33. The edges of the respective shoes 38,' with' the exception of the lowermost one immediately'adjacent'the base bar, are provided with slightly rounded and vertically inclined forward edge surfaces 39 to define .bearing points along a selected path of bend for the sheet materialy while the corresponding forward edge il of the lowermost shoe is concave in form to approximate the mean curvature of the bend path between the adjustment range'there- The rearward edge ofeach shoe 38 within the recess 3 isA provided withav bearing ridge 12 adapted' to'bear against the forward fiatside of an adjustment bar '43 `disposed for rocking movement in the recess 311'. Aby virtue of having a semicircularly lower edge portion fnl seatedin the igroove 29 and an arcuately curved upper edge the arcuate surface portion 3l of the recess.

Threadedy engaged with suitable axially horizontal apertures 41 formed in the housing 33 is a plurality of relatively spaced adjustment screws 43 having their forward ends bearing against the crowned rearward surface 49 of the adjustment bar 43, at points spaced from the pivotal center of the latter, and having their opposite ends exteriorly of the housing provided with longitudinally extending keyways 5|. The arrangement of the parts is such that the screws 48 provide backing for the adjustment bar 43 to hold the latter in a selected position within its rocking range within the recess 34 while the thus secured adjustment bar establishes and maintains the shoes 38 in selected positions of relative horizontal displacement so as to locate the bend-delining surfaces 33 and 4| of the shoes along a curvilinear path with relation to the linear feeding path for the sheet material.

Means are provided for simultaneously moving the screws 48 so as to effect adjustment of the various shoes 38 in unison. Connected to the outer vertical faces of the housing 33, by screws 52 or by other suitable means, are brackets 53 having bushings 54 therein journaling the outer ends of the screws 48 and having recesses 56 therein enclosing pairs of intermeshed helical gears 5l one of which is keyed to its associated screw 43 so that the latter may slide axially in the gear and the other of which is xed to a longitudinally extending control shaft 58 fitted at one end with a hand crank 59. By manipulation of the handcrank to rotate the shaft 58, corresponding rotation will be imparted through the gears 51 to the various adjustment screws so as to retract or advance the shoes 39 and 4| from or toward the rolls 9 and Il.

Figures 6 and '7 illustrate a modified method of applying the pressure to the drive roll I1, and also disclose means of adjusting the initial setting of the rocker arms I2, and the mechanism mounted thereon, relative to the mandrel roll 9. In this embodiment the pressure cylinders 26 are pivotally mounted, in an inverted position, to the underside of the supporting frame 6 and are spaced longitudinally inwardly relative to the complete machine from their respective rocker arms I2. The description will proceed further in the singular, both combinations of rocker arms and pressure applying mechanism being physically and functionally identical. The downwardly extending piston rod 24 is pivotally connected by a pin 6| to the power end 62 of a toggle lever 63, which is mounted on the frame 6 by means of a fulcrum pin 64. i

Thrust is transmitted from the load end 66 of the lever 63 by means of relatively heavy push rod 6l which is formed with rounded ends adapted to seat in complementary depressions 68 and 69 in the confronting surfaces of the rocker arm I2 and end 66 of lever 63 respectively. The depressions 68 and 69 are in substantially vertical alignment and the push rod 61 which is maintained in position therebetween is normally perpendicular to both the rocker arm I2 and the toggle lever 63. As the point of application of thrust transmitted by the rod 6l to the rocker arm vI2 is located some distance from the stub shaft a turning movement is exerted on the rocker arm the force of this movement being greatly multiplied by the added leverage of the toggle lever 63. This additional pressure exerted on material passing between the rolls, provides the traction necessary to handle sheets of rrelatively heavy gauge.

. In order to provide a means of establishing an initial relative location of the xed mandrel roll on the one khand and drive roll and material .feeding and forming elements on the other hand, I provide an adjustable stop 'II in each of the end pillars 7. The stop 7| which is adapted to horizontally adjustable movement in a direction longitudinal to the respective rocker arm I2 extends horizontally from the inner face of the end pillar and projects under the lever arm extension I3 adjacent the end thereof and in movement limiting contact therewith. It comprises a bar of generally square section having a stop portion 'l2 extending into the arcuate path of the lever arm extension I3 and a reduced portion I3 adapted to slidein a parallel slot 14 in the end pillar l. A flanged cap 'I6 is provided for fixed engagement with the inserted end '|3 of the stop '|I and a bolt |'I locking the two members together prevents lateral displacement of the stop relative to the slot 14. An adjusting screw 18 mounted in a tapped hole in the edge of the pillar in alignment with the slot 'I4 extends therein and engages the slot tting portion 'I3 of the stop 1|. The screw 1B is formed with a plain end 'I9 of reduced diameter adapted for thrust seating engagement in a i'lat bottomed hole 8| in the stop I. The extending portion l2 of the stop 'II has been formed with a contacting surface 82 on its upper side which is parallel to the stop longitudinally, but slopes downwardly toward the rocker arm I2 at an angle of approximately 30, and the contiguous end of the lever arm extension is also beveled to form a face 83, which a1- though substantially complementary to the surface 82, is slightly convex whereby line contact only is possible between the two surfaces.

In the preparation of the machine for operation the action of the pressure cylinders will cause the rocker arms I2 to pivot about the shafts until contact is established between the lever arm extensions I3 and the stops 1|; the location of the stops in their respective slots determining the initial relative positions of the fixed and movable sheet forming elements. Adjustment of the screws I8 effecting advancing movement of the stops I I, will create a wedging action between the surfaces 82'and 83 forcing the end of the arm I3 in a downward direction, and thereby adjusting the plate forming elements for the accommodation of heavy material. Conversely, retractive movement of the screws 18 permits the action of the pressure cylinders to force the stops outward thus bringing the fixed and movable plate forming elements into closer relationship. The line contact between the surfaces B2 and 83 of the stop '|I and lever arm extensions I3 facilitates the retractive movement of the stops.

As the sheet material 2| passes between the rolls 9 and Il from the linearA feeding plane dened by the upper surface of the apron I9, the leading edge of the sheet will engage, successively, the portions 4I and 39 of the shoes 38 and will be exed thereby relative to the feeding path to strain the material sufficiently beyond its elastic limit that the sheet will thereafter retain a continuous arcuate curvature depending upon the abruptness of the bend that is imparted to the material. When the shoes 33 are caused to approach closely to the periphery of the mandrel roll 9 the maximum bending of the material will be secured and consequently the radius of bend will be minimized. On the other hand, if the 'shoes1'f38f1arefmovedltoremote ypositions" with respect to the mandrel roll periphery,`theibend"im -pa'rtedi to the material" will? be mu'chf lessf severe andcons'equently the radiusform 'of ther resulti fin'glproduct' willbemu'ch greater. It-will benoted kv"-lthat 'regardless' -of'f-'What' degree' Aof. bend iis being `Aimparted tof'the' sheet material' by the sh'oes,`"the points of 'engagement' o'f theI shoesv with ther-ma- 131 teriale-are alwaysvery 'closeltog'etherso' that, 1in 'eifect; the'-` 'pointsl ''pro'vi'del a substantiallyffcon- -ltinuou's bending-'pathlfor the imaterial 'which- V're- I fsult's inthe formation of 'sn'io'othly and uniformly cur-vedproducts. -fIt fwill be further 'noted'that theshoes 'although' affording a? plurality' of lbe'ar- Y-i'ngpo'i'nts against- Whichlthe material is Aldire'cted J to ffectfbending of the latter,` 'occupy-v acompara- 'ltve'ly's'r'nall overall height and'n'beng.all-slid- A fablein lplanes substantially coinciding' withl the 'lfeding path'ofthe initiallyv flat material'perm'it l thelbearing points. tofbe accurately and :micro-A metrically positioned along and vto define a 5se- 'lect'edv path-of-bend leven? though^the-lateral lmover'n'entsbetween thevarious shoes appears to bei-comparative1yfgreat. lIt'f 'sholdfalso becarel fully-"noted that the lo'wermost' shoe Whichfbears L1 the concavelintroductory surfacefll I-fof-th'e bending `Ipathfhas its point of contact-vith'the adjustvlnie'ntfln'ar'413 very'clcselypositionedfrelative to 'the 'pivotal center f of 4the latterv while the points ofvl contact of thel-fup'p'er shoes areproportionately 11 spaced *upwardly-along the adjustment lbar. This fmeansthat the Various? shoes arenot moved can :equalfdistanceI-laterally at Aeach positional adjnstm'ent 'of-the! bar-43fbut rather -in'- diiering *degrees toeiectproperf`proportionatepo'sition- Fingl of-y the material contact points -to Yproduce vthe 's'moothest 'continuity' of- 'thev bending path. The l lowerl shoe inmo'vingfthe -least fof vany' during all fined by" 'the1material cor'itact"Y surfaces"`v ofthershoes These-elements -it lwill jbe noted are all '-fc'arried by the' rockerar'ml 2 'arid-IS andare-movableunitarilyntherewithj' Tlius regardless" of overall'or localizedsvariationsinthieknessof the' sheet material being passed tli-rogl'rthe* machine, the fouter 'or 'convexfsurface' 'fof 'the r'iished product will'be identical irr'allca's'es. l'lIr'i lthe conventional f types of rolling machines su'chfvarlia-tions'in1thick -fness of f theY material'create 'differences irrY crosssectional form in 'the iinished-a'rticles -withthe rfresult that su'choddsized*articlesfinust be 'given 'special and delay-"creatingtreatment' in'the course ofsubsequent fabrication.

nAlthough I'have 'illustrated'lthelipoiverldriven -mandrel and feedingrfillsY 9 and vil'l'-asf'alfording the-means vfor lintroducingthe sheetlfmaterial -ffromthe linear feedingp'ath' 'intofthelcurvilinearr forming' path, it is 'withinthescope fofthe invention to' lutilize: oth'erl'imeansj" affordV conning of the material-to-saidllinear feeding path,

such as an enclosing passage for thesheetsrand separate means for 'moving the sheets which'may "be in the form of a movable follower for forcibly 'pushing the sheets throughv the passage tov enter means'ldelning a linear feeding path'alongwhich initially straight material may be moved, ya.

-plurality of horizontally offset superimposed-'and substantiallyA iiat bend-forming elements 'enthe curvature of said forming path, land means for moving said material along said feedingfand forming paths.

2. In a machine for curve-bending' material,

Ameans defining a linear "feeding'path- -1 along which a length of initially straight materialfmay be moved toward a terminal point Yof said vfeeding'path, a plurality of horizontally' offset superimposed bend-forming elements disposedclo's'ely I adjacent said terminal point of the feeding path engageable by and to laterally flex said material as the'latter is moved past said terminal point and to direct said flexed material along acurvilinear forming path comprising a'Y continuation of said linear feeding path from\thetermi nal pointV thereof, said elements being lofi-barlike lform and having leading edge por-tions suclcessivelyengageable with said materiaLwme'ans for moving saidbend-forming elements-@inlunison vand in relatively varyingfldegrees" 'to' selectively vary the degree of horizontal o'setvandtoi'alter the-curvature of--said forming path', and'fmeans for moving -said material alongv said feeding.' and formingpaths.

3.3111 a machine for curve-'bending material, a xedly positioned mandreL' means defining' a linear feeding path disposed Y adjacent I said mandrel andV along W`hich initially straight'material may be' movedpast 'said' mandrelin tangential relation thereto, 'feeding meansen'gagingfsaid material for-moving the latter along Vsaid-feeding path -a-'nd 'past' saidvmandrelfa plurality` of individuallyadjustable' superimposed 'bend-forming 'elements "disposed closelyfvadj ace'nt -portions thereon beingengageable .'byV and ar- 'ranged to laterally flex 'said material as" the latter is moved past said pointofftangencyi'and to "directf said yflexed material' along' a' curvilinear "forming/path comprisingl acontinuation". of .said

vlinear feeding path from said-point of tangency.

^ anrl-'means` remote-from said -material engagning-.portionsformoving said bend-forming ele- -mentsdn unison-and --in planes substantially paralleling said linear feeding path' and in' 'rela- -tively proportionate degrees to s'ele'ctively`rarrange 'said elements' to" provide forming paths'of alteredlcurvatures.

4.1 In a machine' 'forcurve-bending material, a'iixedly"po'sitioned'mandrel, means defining a 'relation thereto, a'power'drivenfeeding rolldis- 1Nposedadjacent-said mandrel and for-tractinally v"fen-gaging; saidl sheet material -to movethe" latter along* fsaidffeeding'- p'ath andpa'st saidl mandrel.

a plurality of superposed relatively movable bend-forming elements disposed in an intimate group closely adjacent the point of tangency of the material with said mandrel, said bend-forming elements being engageable by and arranged to laterally flex said material as the latter is moved past said point of tangency and to direct said flexed material along a curvilinear forming path comprising a direct continuation of said linear feeding patlr from said point of tangency, means for moving said bend-forming elements in unison and in relatively proportionate degrees to selectively rearrange said elements to provide foining paths of altered curvatures, and means supporting said feeding path defining means, said feeding roll and said bendforming elements as a unit whereby said unit may be moved bodily toward and away from said mandrel.

5. In a machine for curve-bending material, a ilxedly positioned mandrel, means defining a linear feeding path disposed adjacent said mandrel and along which initially straight material may be moved past said mandrel in tangential relation thereto, a power-driven feeding roll disposed adjacent said mandrel and for tractionally engaging said sheet material to move the latter along said feeding path and past said mandrel, a plurality of superposed relatively movable bendforming elements disposed in an intimate group closely adjacent the point of tangency` of the material with said mandrel, said bend-forming elements being engageable by and arranged to laterally flex said material as the latter is moved past said point of tangency and to direct said flexed material along a curvilinear forming path comprising a direct continuation of said linear feeding path from said point of tangency, means for moving said bend-forming elements in planes substantially paralleling said feeding path and intersecting said forming path and in relatively differing degrees to dispose the points of engagement of the bend-forming elements with said material along a prescribed forming path, and means supporting said feeding path dening means, said feeding roll and said bend-forming elements as a unit whereby said unit may be moved bodily toward and away from said mandrel.

6. In a machine for curve-bending material, a xedly positioned mandrel, means defining a linear feeding path disposed adjacent said mandrel and along which initially straight material may be moved past said mandrel in tangential relation thereto, a power-driven feeding roll disl posed adjacent said mandrel and for tractionally engaging said sheet material to move the latter along said feeding path and past said mandrel, a plurality of superposed relatively movable bendforming elements disposed in an intimate group closely adjacent the point of tangency of the material with said mandrel, said bend-forming elements being engageable by and arranged to laterally flex said material as the latter is moved past said point of tangency and todirect said flexed material along a curvilinear forming path comprising a direct continuation of said linear feeding path from said point of tangency, a member mounted for rockable movement adjacent said bend forming elements and engaging the latter to move them in unison and in relatively proportionate degrees to selectively rearrange said elements to provide forming paths of altered curvatures, means engaging said rockable member for moving the latter to selected positions of rocking movement, and means supporting said feeding path defining means, said feeding roll and said bend-forming elements as a unit movable bodily toward and away from said mandrel.

7. In a machine for curve-bending material, a xedly positioned mandrel, means defining a linear feeding path disposed adjacent said mandrel and along which initially straight material may be moved past said mandrel in tangential relation thereto, a power-driven feeding roll disposed adjacent said mandrel and for tractionally engaging said sheet material to move the latter along said feeding path and past said mandrel, a plurality of superposed relatively movable Ybend-forming elements disposed in an intimate group closely adjacent the point of tangenoy of the material with said mandrel, said bend-forming elements being engageable by and arranged to laterally flex said material as the latter is moved past said point of tangency and to direct said flexed material along a curvilinear forming path comprising a direct continuation of said linear feeding path from said point of tangency, a member mounted for rockable movement adjacent said bend forming elements and engaging the latter to move them in unison and in relatively proportionate degrees to selectively rearrange said elements to provide forming paths of altered curvatures, means engaging said rockable member for moving the latter to selected positions of rocking movement, means supporting said feeding path deilning means, said feeding roll and said bend-forming elements as a unit movable bodily toward and away from said mandrel, and yieldable means for forcibly urging said unit toward said mandrel to maintain tractional engagement between said mandrel, feeding roll and said material.

8. In a machine for curve-bending material, a supporting frame having an axially horizontal rotatable mandrel roll journaled thereon, rocker arms mounted for pivotal movement on said sup.. porting frame and positioned adjacent said mandrel roll, guide means on said rocker arms for supporting initially straight material and along which said material may be moved in a feeding path tangentially toward and over said mandrel roll, a material feeding roll journaled on said rocker arms and arranged in axially parallel relation with said mandrel roll, said feeding roll being movable upon rockable movement of said rocker arms toward said mandrel roll to engage said material tractionally between the confronting peripheries of the feed and mandrel rolls and to move said material along said feeding path, means connecting said feed and mandrel rolls for unitary rotary movement, pressure means for urging said feed and mandrel rolls together to effect said tractional engagement of the rolls with said material, a bend-forming shoe comprising a plurality'of superposed bars slidable on said rocker arms in planes substantially paralleling the feeding path of said material, said bars each having thereon a portion positionable to form a point along a curvilinear bending path for the material which comprises a direct continuation of said feeding path, as the latter is moved to laterally ilex the material a predescribed amount beyond its elastic limit to impart a permanent curvilinear bend to said material, and means for moving said bars in unison and in proportionately varying degrees to establish bending paths of selected different curvatures.

9. In a machine for curve-bending material, a supporting frame having an axially horizontal 13 on a portion positionable to form a point along a curvilinear bending path for the material which comprises a direct continuation of said feeding path, said points being successively engageable with said material as the latter is moved to laterally flex the material a predescribed amount beyond its elastic limit to impart a permanent curvilinear bend to said material, a base bar carried by said rocker arms and extending longitudnally parallel with said rolls and said shoe bars, said base bar having therein a longitudinally extending groove, a rocker bar disposed in said groove and pivotally mounted thereby on said base bar, said rocker bar engaging said shoe bars, a housing carried by said base bar and having a portion thereof overlying said shoe bars to define with a surface of the base bar an opening through which said shoe bars may slidably move, said' housing also having therein a recess extending parallel to and confronting the groove of said base bar. said recess having a transverse crosssectional contour which is an arc centered in said groove, a rocker bar having an edge portion thereof engaged in said groove and an opposite edge portion slidably engaged in the housing recess, said rocker bar also being disposed in engagement with said shoe bars, and a screw engaged in said housing and bearing against said rocker bar for moving the latter and the shoe bars in unison and in proportionately varying degrees to establish bending paths of selected dierent curvatures.

13. In a machine for curve-bending material, means dening a generally horizontally disposed linear feeding path along which initially straight material may be moved, a plurality of movable bend-forming elements engageable by and to laterally flex said material and to define a curvilinear forming path comprising a continuation of said linear feeding path, means for moving said bend forming elements in unison in solely a horizontal direction and in relatively varying degrees to alter t-he curvature of said forming path, additional means for moving said bend forming elements in unison in substantially'a vertical direction yand in relatively fixed degrees to accommodate materials of different thicknesses, and means for moving said material along said feeding and forming paths.

LLEWELLYN W. EVANS.

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

UNITED STATES PATENTS Number Name Date 928,073 Schneider July 13, 1909 957,609 Kane May 10, 1910 1,351,472 Farmer Aug. 31, 1920 1,783,187 Elliott Dec. 2, 1930 1,905,515 Smith Apr. 25, 1933 1,943,407 Yoder Jan. 16, 1934 FOREIGN PATENTS Number Country Date 162,257 Great Britain July 26, 1920 468,476 Great Britain July 6, 1937 774,509 France Sept. 24, 1934

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