US2465705A - Contour forming machine - Google Patents

Description

March 29,- 1949. c. .1. BATH CONYTOUR FORMING MACHINE 4 Sheets-Sheet 1 Filed Sept. 28, 1946 I INVENTOR.

BY CYRI/L J. BATH m a JMak AWO ENEYS March 29, 1949. c. J. BATH CONTOUR FORMING MACHINE 4 Sheets-Sheet 2 Filed Sept. 28, 1946 INVENTOR. CWZ/L J. BATH March 29, 1949. c. J. BATH CONTOUR FORMING MACHINE 4 Shets-Sheet 3 V .INVENTOR.

CYR/L J. BATH Filed Sept. 28, 1946 m 8 QTTOENEY.

March 29, 1949. I c. .1. BATH CONTOUR FORMING MACHINE 4 Sheets-Sheet 4 Filed Sept. 28; 1946 fig. 8

INVENTOR. CYR/L J BA TH BY ATTORNEYJ.

Patented Mar. 29, 1949 UNITED STATES PTENT OFFICE CONTOUR FORMING MACHINE Cyril J. Bath, Chagrin Falls, Ohio Application September 28, 1946, Serial No. 699,975

9 Claims.

The present invention relating as indicated to contour forming machines has more particular regard to certain improvements in so-called tangent benders f the type capable of bending or forming flanged members to selected curved contour without causing the objectionable wrinkling or buckling or the flanges experienced prior to the advent of such benders. As illustrating the character of work piece which the present improvements are designed to produce, such metal structures as the curved bumpers on motor vehicles, frame members or carlings, cabinet sections and the like which are characterized by having portions thereof bent or formed to a desired shape and also have a flange or flanges extending along such bent or formed portion-s either for stiffening purposes or as a part of the structure.

The successful bending of flanged members in such machines is of course attributable to the continuous support of the flanges against buckling at and immediately adjacent the point of bending. However, machines now in general use while capable of satisfactorily bending flanged members are inherently slow multimovement machines. Such slowness in addition to retarding production of members which can be formed while cold, makes such machines undesirable for forming members while hot because of the cooling of the members in the interim between clamping the same in the machine and the making of the last bend therein. Furthermore, such machines are suitable for forming only circular arcs and require a different set of gears in mesh with the rack on the bending shoe for each different radius to be bent.

Typical examples of so-called tangent benders are disclosed in Lee B. Green Patent No. 2,287,833 issued June 30, 1942 and it can be readily seen therefrom that the bending or forming of the cabinet section illustrated comprises four principal movements of the machine viz:

1. Clamping the work piece between the relatively movable male and female dies.

2. Actuating the rockers associated with the female die in one direction to displace the projecting ends of the work piece into engagement with the male die.

3. Actuating the rockers in an oppositedirection, and

4. Unclamping the work piece.

Accordingly, it is one principal object of this invention to provide a machine which is capable of forming the work piece with one or more bends therein in one continuous movement of one of the dies and yet retaining the feature of being 2 able to form contours in flanged members without the objectionable buckling or wrinkling of the flanges thereon.

It is another object of this invention to provide a machine wherein the work piece is formed to desired contour not only by the tangential bending action as in the prior art machines, but in addition by a drawing or wiping and an ironing action which still further minimizes the possibility of wrinkling or buckling of the flanges.

It is another object of this invention to provide a machine in which there are novel means for causing the rockers associated with the female die to follow any desired contour on the male die without requiring specially formed interlocking means between them.

It is another object of this invention to provide a machine in which there is a novel die structure for forming channel shaped stock to desired contour in a direction transverse to the flanges thereof.

It is another object of this invention to provide a machine having a novel die structure for forming desired contour stock having a generally transverse flange along one edge and a channel along its other edge opening toward such flange.

It is another object of this invention to provide a novel method of forming work pieces to desired contour.

Other objects will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

Fig. 1 is a plan view of a preferred form of machine;

Fig. 2 is a front elevational view partly in vertical cross-section of the machine illustrated in Fig. 1;

Fig. 3 is a view of the female die as viewed from line 33 of Fig. 2;

Fig. 4 is a top plan view of the die mechanism showing the same in a position ready for forming a work piece;

Fig. 5 is a view similar to Fig. 4, except show-' ing the die mechanism in a position completing the last bend in the work piece;

Fig. 6 is a top plan view of a modified form of machine;

Fig. '7 is a front elevational view of the machine illustrated in Fig. 6;

Fig. 8 is a top plan view of a die mechanism for forming stock having a transverse flange along one edge and a channel opening toward such flange .along its other edge; and

Fig. 9 is a central vertical cross-section view taken along a line9 9 Fig. 8.

Referring now to the drawing and first to Figs. 1 to 5, the machine illustrated therein comprises a bed or frame 5 on which is mounted an upright longitudinally adjustable member 2" and. an; p-w right reciprocable member 3. The bed] hessuit; able guideways 3 thereon on which said upright members are slidable.

The mechanism for reciprocating member 3 comprises a motor '5, a gear train 6, a crankshaft I rotatably supported in bearing boxes 9, and a connecting. rod 8 pivotallyconnected: to the crankshaft and: to. one; end; of the member 3. All: of said elements are interconnected: as clearly shown. in the. drawings so that one full revolution of the crankshaft 1- will effect reciprocation ofmember 3: toward and away. from member 2.

Mounted on member sis-an: intermediate mem ber I 0. which: is rotatable 90 fromthe position shown in. Fig. 11 to. a; position. transverse of the: bed I. Such. rotation iseffected. through a shaft Ll: connected: to member 1 0. and. rotatably supported in. member 3, such shaft It being rotated by means of a motor t2; Member 3 is, provided: witlr suitable stopsnot shown; for limiting rotation; of; member it; between. the aforesaid positions.

Securedztoone. end of member H1 is amale die [@ywhich has a face. of contour torwhichit; is desired; to form. the stock. The stockherein illus-v t atedi ras ra ght ei av naalo its r s tive edges generally transverse flanges. Such-1 i nals: t be curv d. anw i a aw 511' V Q iQ -lt 3 a Q l QSQ Q i to flahges; in the. finished cabinet. serving as. means for-securinga doorand, arear panel. thereto. The. male, die; L3 is. adapted. to. engage the innerface Of;- the, stockand, to lie. closelyv adj acent the inner race-s O the lan es.

At the other'end' of member I0 is a knockeout.

i4. wh hfi e iprocab frelat ve o me be ill by means oi'a pneumatic cylinder 1 5 or thelilse, and. adapted, hen m mbe a. is r t ted. to a gcsi iqn ransv rsa i he ed. o n age the nds. hey mhle ed Work. pi ce n o s ce. he same from the male die i's'to' thus facilitate removal of the finished work piece. The die l3 preferably-includes hardened inserts I6 at its upper and lower edges to thus provide hard wearresisting-surfaces inengagement with the flanges ofthe-work-piece.

Upright member- 2* as previously indicated is longitudinally adjustable along the bed I, such ad jii'stmentbeing efiected: by rotating a screw I! having threaded engagement with bed I. The. femaledie which: cooperates with male die. [3 to form: a. straight work. piece into. desired: contour is carried by member 2 and comprises three. parts; namely,- anintermediatepart t8: and. two adjacent rockers IS; the latter forming-continua. ati'o'n's. oi -pant I8: and all threeparts being engageable withthe. outer faceof: the work; piece and lying closely adjacent the outer-surface. of;

the: flanges thereof? The: intermediate di'e. part mii's. ofi'transverseawidth less. than; that ofzthe male die I3 and is formed-swith;arworkipieceren the member 2.

gaging surface similar to the corresponding portion of the male die l3. In the present case, the male die 23 and the intermediate die part l8 are provided with slightly curved complementary surfaces to form a curved crown in the work piece when the same is initially clamped between die [3 part it.

The intermediate die part 45 is reciprocable in member and is yieldably held in the position shown in Figs. 1 and 2 preferaltllyv by an air cylinder 20' although a coil spring or the like may be used if desired, When an air cylinder is used, the pressure therein is sufficient when the male die $53 is moved toward the intermediate die part E8 to clamp a work piece therebetween and to form the crown in the work piece and to continuously. engagethe work piece during the forming of the laterally projecting ends thereof around the relatively short radius curves at each lateral end of the male die 13.

The rockers ie, are respectively disposed adjacent t laterali ends, ofi'theintermed-iate diet-part. and are rotatably carriedin member 2. The trunnions 2i onqtherockersare rotatablein bearing. rnernbens 2-2. which, are reciprocably mounted in. laterally extending slots 23- in; member 2:. In order to yieldablysurge the rockers late a position adjacent. theends of die part I8 air cylinders.- 2% fixed to: member 2. arev employed, member 2: having threaded thereinto. a stop; screw; 24.; the; end of: which. is engageable with sleeve 22, to thus prevent engagement of the -edge oi: the rockers; I591 with the edgesof die part l8.

Yieldably. holding the. rockers; I 9 in line; with oneanother and with; part-1 t8 arevair cylinders2 5 having the rod portions thereof pivotally corrneoted: to. rockers it at pointseccentric of the trunn-ions' 21. Gylinders 25; are: pivotally connected: tov member, 2 andsuitable means, such as those shown are; provided; forlaterally adjusting thepivot .az zes thereof.

It: can nowbe seen that when; the parts of the; machine areintheposition shown in Figs-l 1, 2; 3; andvl; a work piece-maybeplacedracross the. fe-. male die. The successivestepsin one'complete; cycle of the machine will bedescribed without regard toany particular-pipingand wiringd-iagrams; for coordinating suchsteps, it; being within the. skill of any, electrical;andhydraulio engineer to.

. provide for such coordination upon. diSQlOSllI'ea cit-he desired steps; and their sequence. Witha; work piece properly; positioned across the female. die, the; motor 5 can. be started to rotate crank; shaft I'andto thus move. the'member 3=toward Such movement clamps the; work piece between the male diev I-3and thaintermed-iatedie part; l8 and thus forms the crown; therein. Continued movement of member 3511b sequent to clamping of the work piece effects movement of; the intermediate diepart I 8 in; unison with male diel3; thereby: constantly clamping: the. work piece under regulated; pressure as determined by the pressure; in cylinder 20. During the movement ofimale. die l'3- and intermediate die. part. I and the. work: piecert'he- Such dual .-action causes the work piece.

at the lateral ends of the male die [3 whether they be circular arcs, elliptical arcs or any other curved surface. When the ends of the finished work piece are to be parallel it is preferred that they be over-bent slightly to compensate for spring back thereof. To accomplish the overbending in the particular example shown, the air pressure in cylinder 26 is reversed whereupon the rockers (3 are forcefully rotated to the position shown in Fig. 5 wherein the work piece engaging faces thereof are rotated to positions beyond lines which are parallel to the direction of movement of member 3. At this point of the cycle, the crank has rotated through 180 whereupon continued rotation thereof will move member 3 toward the left as viewed in Figs. 1 and 2 away from member 2. At the same time the pressure may be reversed in the cylinders 20, and 25 to permit ready separation of the male die I3 and the work piece from the female die. After the crank 7 has rotated 360 the motor 5 can be shut off and the intermediate member H) rotated 90 to a position where the crown portion of the cabinet section so formed is transverse of the bed I. The knock-out plate M can then be actuated so as to engage the ends of the work piece and to thus free the same from die [3. The work piece is then removed and the intermediate member ID rotated 90 in opposite direction ready for forming another work piece.

From the above it can be seen that a work piece is completely formed by one continuous movement of one of the dies, first in one direction and then in the opposite direction. Furthermore, no intermeshing gears and racks are required between the male die and the rockers 19 in order to insure that the work piece engaging faces of the rockers will be tangent to the work piece as it is being formed. Likewise, the rockers is will follow any curved contour of the male die l3.

A further feature growing out of the present invention is that the work piece is formed by a drawing or a wiping action by reason of the resistance offered by the rockers l9 to rotation. Thus as the male die I3, the intermediate die part l8 and the work piece move toward the right as viewed in Figs. 1, 2 and 5, there is a sliding or wining and an ironing action of the rockers l9 against the work piece. The magnitude of such wiping and ironing action is of course controlled by the amount of air pressure in the cylinders 25 and 26.

Insofar as the machine illustrated in Figs. 6 and '7 is the same as that illustrated in Figs. 1 to 5, like reference numerals have been used to designate like parts. In Figs. 6 and 7 the upright reciprocable member 3 is reciprocated by means of an air cylinder the piston rod 3| of which has a rack thereon in mesh with a gear 32, which gear in turn rotates a crank 33. A pair of curved links 34 have their respective ends pivotally connected to the crank 33 and to the member 3. In this form of the invention the crank 33 is rotated 180 in opposite directions during one complete cycle of the machine. Also, the intermediate member ID is herein shown as being rotated by means of a cylinder 35 through a rack and gear 36 and 31. One primary difference between the form illustrated in Figs. 6 and 7 and that illustrated in Figs. 1 to 5 is that in the former, the rockers H) are rotatable about a fixed axis thereby limiting the width of die 13 which can be used; but there is yet included in this modified form the wiping and ironing action on the work piece as the male die and the intermediate die part l8 move in unison relative to the rockers l9. Such wiping and ironing is effected by the resistance to rotation of the rockers l9 by the cylinders 25. Inasmuch as the general operation of the machine illustrated in Figs. 6 and 7 is the same as that of the machine illustrated in Figs. 1 to 5, such operation will not now be repeated.

While the above described machines have particular utility in the forming of flanged members such as the cabinet sections illustrated because the forming dies closely embrace the flanges at and immediately adjacent the point of bending to prevent buckling or wrinkling of the flanges and also because of the stretching of the work piece due to the drawing or wiping action during bending, it is to be understood that flat sheet stock, angle bars, T-bars, Ibeams and etc. may be formed with equal facility.

Referring now to Figs. 8 and 9 there is shown therein a novel die arrangement for making cabinet sections, for example, from stock which is formed along its respective edges with a generally transverse flange ii? and a channel 4! open toward such flange. Where such stock is to be formed as shown, there is preferably a notch 32 in each corner of the channel M to provide for a sharp inner corner and an outer corner of relatively small radius when the stock is bent. To my knowledge, no one has heretofore been able to transversely form stock .vi'th of success because of the attempt to engage the forming faces of the dies with only the outer faces of the parallel flanges 53 and M of the channel 4|. Therefore that portion of the die structure described below which relates to the formation of the parallel flanges 3 and M to a desired curvature is applicable as well for forming the flanges of channel shaped stock which consists only of a channel 4H without a flange Aid. In the illustrated cabinet section, the crown is curved both in vertical and horizontal planes.

In this novel die structure, the female die is formed in three parts as is the female die in Figs. 1 to '7. The male die is, however, made in two parts, one part being engageable with a portion of the inner face of the stock and the outer face of the channel flange 4 and the inner face of flange 4E! and the other part mi being in the nature of a supplemental die interposed within channel 4! and having a face thereof engageable with the remainder of the inner face of the stock and also the inner face of the channel flanges 43 and 44. All of the faces of both parts are curved to conform to the desired final form of the stock except that face which is engageable with the inner face of the channel flange 64; such face being normally straight as shown. Such face is part of a flexible element 47 which is secured at its middle to part 36. The ends 48 of the flexible element All are free to be displaced transversely relative to the middle thereof to, in efiect, wrap the channel flange it onto the curved face of part 55 which engages the outer face of the channel M. The ends 58 are displaced by means of pins 23 secured thereto and projected through the part 45 into engagement with the inner face of the channel flange 53.

It can now be seen that when the male and female dics are brought together to clamp and form the crown in the stock, the engagement of the female concavely curved die with the outer face of the channel flange 43 will be at points opposite the ends of pins 49 and thus the forming of the channel flange e3 automatically displaces the ends 48: of the flexible element t? to displace. the channel flange M toward the curved face of part 651' opposite the outer face of the channel flange 4 :33. During such displacement the middle of the convex face of part 15 will be in engagement with the outer face of the channel flange 44 at a point corresponding with the middle of the flexible element 4'! and at the same time the middle of the convex face of part 48 will engage the inner face of the channel flange 43 at a point also corresponding with the middle of the flexible element .7 whereby both channel flanges will be simultaneously formed, Having thus formed the crown of the cabinet section, the projecting ends ofthe stock are drawn or wrapped around the remaining: portion of the male die in the manner described above in relation to Figs. 1 to 7. As previouslymentioned, this much of the die structure may be used for forming channel shaped stock formed, for example, with just a plain channel M including the spaced flanges 43 and M.

In order'to remove the completely formed stock the parts 85 and to must be displaced relative to one another out of alignment to disengage the flange to from part 45 to thus permit the finished work piece to be displaced or lifted upwardly from part 55. Such relative displacement of parts to and 65 in the case of a cabinet section such as illustrated is preferably along an inclined plane so that the flanges All on that portion of the cabinet section which forms the side walls can be moved upwardly relative to part 45. Suitable means such as the air cylinder 5! may be employed to actuate the part Q6 relative to the part 65'. Transverse displacement of parts 45 and 46 relative to one another is also desirable in order to disengage the curved face of part 45 from the transverse flanges 50 on the channel M.

As soon as the completed cabinet section is re-' moved the flexible element ll flexes or springs back to its normal straight form and the pins 4 9 accordingly pop out with the ends thereof in line with the middle of the convex face of part 46 ready for slipping on of another straight piece of stock onto the male die.

Part 45 is preferably formed with a T-slot in which part 46 is slidabl guided so as to partake only of inclined movement relative to part 45.

from one another and having forming faces enspouse to movement of said dies toward one another.

2. A di for forming channel-shaped stock in a direction transverse of the flanges thereof,

comprising a pair of dies movable toward and away from one another and having forming faces engageable with the outer faces of such flanges respectively and shaped to conform to the desired finished form of the stock, a supplemental die interposed between said dies and adapted to lie between such flanges and having one face conforming to the finished shape 0f the inner face of one flange, a flexible element on said' supplemental adapted to be flexed to the finished shape of the inner face of they other flange and normally being differently shaped therefrom, and means interposed between said element and the inner face of the first-named flang and movable in response to movement of said dies toward one another to so flex saidv element.

3 A die for transversely forming a piece of stock having at its respective edges a flange extending generally transversely of the stock body and channel open toward such flange, comprising a pair of dies movable towardand away: from one another and having forming facesen gageaslerespectively with the inner and outer of the stock body, and said die which is engageable with such inner face having a porticn thereof movable relative to the remaining portion thereof toa position in line. and. out. of line therewith, such portions having forming faces engageable respectively-with the inner and outer faces of that portion of the channel whichisspacedfrom and opposite the stock body.

A die for transversely forming a piece of stock having at its respective edges a flange. ex-= tendinggeneraliy transversely of the. stock body and a channel open. towardsuch flange, com.- prising a pair of dies movable toward'andaway from one another and having forming faces engageable respectively with the inner and outer faces of the stock body, and said die which. is engageable with such inner face having a portion thereof movable relative to. the remaining portion thereof to a position in line and out of line therewith, such portions having forming facesengageable respectively with the inner and outer faces of that portion of the channel which isspaced from and opposite the stock body, and. being arranged so that when moved to. a position out of line with one another wherewith theremai-ningportion is disengaged from the surface of'the flange which faces toward the channel, the stock. may be fitted onto or removed from the portion thereof which fits into such channel.

5. In acontour forming machine, the combination of main and. wing dies movable rela tive to one another along a predetermined path, said main die being formed with a convexly curved surface, clamping means operative to clamp a. workpiece to said main die in a laterally extend ng position with respect to such path;

and with a portion of the workpiece projecting laterally beyond'such curved surface, said wing die being, formed with a surface engageable with such projecting portion of the workpiece, pivot means supporting said wing die for swinging. movement around such curved surface of said main-die'by such projecting portion of the workpiece in response to relative movement of said dies, means supporting said pivot means for movement laterally of the path of said dies, meansv yiieldably urging the pivot. means t'oward such path, and reversible power means selectively operable for yieldably imposing a resultant turning moment on said wing die in opposition to but less than that effected by the projecting portion of the workpiece as aforesaid, and for yieldably imposing a resultant turning moment on said wing die supplementing that effected by the projecting portion of the workpiece as aforesaid.

6. In a contour forming machine, the combination of a pair of main dies movable relative to one another along a portion of a predetermined path to clamp a workpiece therebetween with a portion of the workpiece projecting laterally beyond said dies and movable together with such workpiece along another portion of such path, a wing die engaged by the projecting portion of the workpiece, means supporting said wing die for swinging movement by the workpiece laterally toward said main dies about an axis transverse to the length of such path, means supporting the pivot means for movement laterally of such path, means yieldably urging said pivot means laterally toward such path, and reversible power means selectively operable to yieldably urge said wing die to swing about said pivot means awa from such path with sufficient force to impose a resultant turning moment on said wing die of sufficient magnitude to eifect forming of the projecting portion of the workpiece by wiping action to conform with one of the main dies between which it is clamped and beyond which a portion thereof initially projected and to yieldably urge said wing die to swing about said pivot means toward such path with sufficient force to impose a resultant turning moment on said wing die of sufiicient magnitude to effect overforming cf the projecting portion of the workpiece to compensate for spring back therein.

7. In a contour forming machine, the combination of a pair of relatively movable members, one of said members being formed with a surface of contour to which it is desired that a workpiece conforms when finished, means for clamping a workpiece to said one of said members with a portion of the workpiece projecting laterally therebeyond, a wing die rotatably carried by the other of said members adapted to be engaged by and rotated by the projecting portion of the workpiece to thus progressively force the workpiece into engagement with said one of said members in response to relative movement of said members toward each other, and reversible power means connected to said wing die and selectively operable for yieldably resisting rotation of said wing die during such relative movement to thereby effect forming of the workpiece by a wiping action, and for forcefully rotating said die at least during the latter part of such relative movement to overform the workpiec and thereby compensate for spring-back thereof.

8. A contour forming machine comprising a main die having a convexly curved corner surface at one lateral margin and being movable along a predetermined path, clamping means operative to clamp a workpiece to said main die in laterally extending position with respect to said path with a portion of the workpiece projecting laterally across the path of said curved corner surface, a wing die having a curved surface which is co-nvex toward said main die, pivot means supporting said wing die for swinging movement about an axis generally parallel to the axis of said curved corner surface of the main die, suppor ing means supporting said pivot means for movement generally laterally of said path, yieldable means yieldably urging said pivot means toward path, to dispose the curved surface of the wing die in the path of said corner surface, said pivot means, supporting means, and yieldable means being arranged and cooperative concurrently normally to maintain the curved surface of the wing die in yielding pressure engagement with such projecting portion of the workpiece so that the curved surface of the wing die can roll the workpiece about said curved corner surface of the main die with resultant swinging oi the wing die in one direction about its pivot, upon movement of the main die along a portion of its said path on its forming stroke, and yieldable restraining means in addition to said yieldable means operatively connected to the wing die and opposing the swinging movement thereof in said direction with sufficient restraining force to partially overcome the said rolling action of the wing die curved surfac and to cause said curved surface of the wing die to partially slide on the workpiece around said corner surface under sufficient pressure to tension the workpiece while the curved surface partially rolls thereabout.

9. The contour forming machine according to claim 8 characterized in that said yieldable restraining means is a fluid pressure operated piston and cylinder assemblage.

CYRIL J. BATH.

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

UNITED STATES PATENTS

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