US2986194A - Rapid cycle stretch and wipe forming machine - Google Patents

Description

May 3o, 1961v R. F. DE MARCO 2,986,194

RAPID CYCLE STRETCH AND WIPE FORMING MACHINE Filed Deo. 3, 1959 4 sheetssheet 1 Z g & INVENTOR.

Arme/V514 May 30 1961 l R. F. DE MARCO RAPID CYCLE STRETCH AND WIPE FORMING MACHINE Filed Dec. 3, 1959 4 Sheets-Sheet 2 wrok/Vex May 30 1961 R. F. DE MARCO RAPID CYCLE STRETCH AND wIPE FoRMINC MACHINE Filed Dec. 5, 1959 4 Sheets-Sheet I5 wm, Mm.

May 30 1961 R. F. DE MARco 2,986,194

RAPID CYCLE STRETCH AND wIPE ECRMINC MACHINE Filed Dec. 5, 1959 4 Sheets-Sheet 4 v 6% .r y

a-Tm L l vINVENTOR.

W5. @MM BY 4i* Arme/VEZ United States Patent" G RAPID CYCLE STRETCH AND WIPE FORMING MACHINE Robert F. De Marco, Mentor, Ohio, assignor to The Cyril Bath Company, Solon, Ohio, a corporation of Ohio Filed Dec. s, 1959, ser. No.` ss7,1os

4 claims. (ci. 15s-sz) This invention relates to a rapid cycle combined wipe a'nd stretch forming machine, and particularly to a wipe and stretch forming machine in which the wipe forming assemblage and the stretch forming assemblage are carried on a common carrier about the side face of the die about which the metal is to be formed.

More particularly, the present invention is one wherein a stationary die is supported so that the metal can be stretched formed about its side face, a pair of piston and cylinder assemblages for stretch forming are carried by carriers which swing in opposite directions about the die so as to stretch form the metal onto the die face, and these same carriers each carries a wipe forming assem- Iblage by virtue of which the stock is wipe formed onto the face concurrently with the stretch forming operation.

` Another specific object is to provide a combined wipe and stretch forming machine with an embossing die by virtue of which the stock can be embossed at one location and held by the embossing die at that location while being stretch formed and wipe formed in opposite directions therefrom.

` Various other objects and advantages will become apparent from the following description wherein reference is made to the drawings disclosing a bumper forming machine embodying the principles of the present invention, afnd wherein:

Fig. 1 is a perspective view of a machine embodyingV the principles of the present invention;

Fig. 2 is an enlarged `fragmentary longitudinal sectional v'iew of the machine illustrating the cooperation of the main forming die, the embossing die, and wipe shoe, w'ith the stock;

i Fig. 34 is a sectional view taken on a line 3'3'of Fig. 2;

Fig. 4 is a diagram showing the wipe forming shoes in position at the start of and at the end of the forming operation,I respectively;

- Fig. is a diagrammatic illustration of the forming parts of the machine in a starting position preparatory to being applied to the stock;

Fig. `6 is a diagrammatic illustration showing a condition of the parts of the machine to be overcome by one feature of the invention, and illustrating certain problems in the position of the stretch forming assemblages; and

Fig. 7 is a flow diagram illustrating a simple hydraulic' operating and control systemwhich may be used in connection with the machine.'

Referring to the drawings, thev machine comprises aY frame, indicated generally at 41, having an upright por tion 2 and a lateral guide portion 3.

Mounted on the frame in xed position is a side face die D having its forming .face disposed upwardly and generally horizontally.

Mounted onV the upright portion 2 is a' sliding die support `4 on the lower end of which is carried an embossing die E arranged for cooperation with the side face of the die-D near the mid-portion thereof. The embossing die Eis arranged to be moved upwardly away from the die D and downwardly into engaging position therewith.)- l

For this purpose, the slide 4 is carried on a suitable upright guide 5 on the frame portion 2. A suitable piston and cylinder assemblage 6 including a cylinder 7 and a piston 8 having a `rod 9 are mounted on the upright frame portion 2'. The cylinder 7 is ixedly secured to .the frame and the piston rod 9 is connected to the carrier 4 Ifor movement therewith. Thus, upon operation of the piston and cylinder assemblage 6, the embossing die E may be moved to raised and lowered positions, respectively. As mentioned in the objects, it is'desired to eiect an embossing operation on the workpiece while stretch forming and wipe forming the workpiece. For this purpose, a pair of arms 10 are mounted on the frame. Each of the arms 10 is arranged to swing about a rhorizontal axis. In the form illustrated, Ithe arms are shown as supported on trunnions or pivots 11 for swinging abou separate axes.

Each arm 10 is comprised of a wipe forming assembly supporting portion 12 and a stretch forming assembly supporting portion 13, these portions being in tixed position to each other and rotatable as a unit about the axis offtheir pivot 11 and providing a carrier pivotally connected to the frame for swinging about a predetermined axis. The radially outward or peripheral margins of the portions 12 and 13 provide guide means which are received in suitable guideways 14 in the guide portion 3 of the frame and coaxial with the pivots 11, respectively, for preventing the arms from warping or springing out of their planes normal to the axes of the pivots 11.

In order to swing the arms about the axes of their pivots y11, they are provided with a piston and cylinder assemblage 15, respectively, each of which includes a cylinder 16 pivotally connected at 17 to the frame portion 2. Reciprocable in each cylinder 16 is a piston 1 8 having a rod 19 which is pivotally connected, as indi-- cated at 20, to its corresponding one of the arms 10. Thus, by manipulation of the assemblages 15, the arms 10 can be swung yfrom a starting position, in which the wipe forming shoes are adjacent the ends of the embossing die, outwardly and downwardly to the position illustrated in Fig. 1.

In the form illustrated, each arm and its assemblagesl are essentially the same in -form and function, and one arm only will be referred to in detail.

The wipe forming assemblage of the arm 10 comprises a piston and cylinder assemblageZl including a cylinder 22 secured in iixed position on the armY portion 12v 24 for actuation by the piston and cylinder assemblageA 21. In the form illustrated, the assemblage carries a wipe shoe comprising aroller 27 Yconfigured so as torconl form properly to the side kface ofthe die D. Y Since it is desired lthat theroller initially engage the stock in apredetermined rotated position, `each roller ,is mounted on a shaft 28 which, Yin turn, Vis connected to a suitable coil spring return 29 so arranged that, as the roller rolls from starting position lto final position, the spring, is wound up, and when the roller is released, it is returned to its starting rotated position about its shaft yand stopped in that position. 'I'he wipe shoe roller 27 is arranged to engage the stock adjacent the opposite ends of the' embossing die E when starting the cycle. However, it is4 necessary in order to`properly feed the stock,Y into the stretch forming mechanism; that the stretch forming-pis-r ton and cylinder assemblages be arranged so as to en- Patented May 30, 1961V ly to' the midportion of the side face of the die D preparatory to the engagement ofthe stock by the embossing die or the wipe forming shoes 27. At the same time, after the stock is` initially stretched by the stretch-.formingassemblages, it must '.be. partially laid on the die face..

so that there is no tendency toward reversebending of the stock away `from the die Vface by the stretch forming assemblages after the application of the embossing die and the wipe forming shoes 27, all as is explained more fully hereinafter in connectiomwith the operation of the. machine.

Each stretch formingY assemblage comprises a piston and cylinder assemblage 35` including a cylinder 36 with a piston 37 reciprocable therein and having a pistorrrod 38; A stretch forming head 39 is Vcarried on the outer endofthe rod 38'and is adapted to clamp at one end ofj` the length of stock for exertingtension thereon.

For the Ypurposes described in U.S.` Patent No., 2,514,- 830, issued July 1l, 1950, to Cyril J. Bath, it is desirable that the stretch forming assemblage be arranged for pivoting about an axis on the arm portion 13 so that it can position itself with its cylinder axis in proper tangential relation to the instantaneous line of contact of the stock and the side face of the die D. For this purpose, the cylinder 36 is supported in a suitable mounting bracket 39a,which is connected by a pivot 40 to a suitable slide 41, the axis of the pivot 40 beingiat right angles to the axis of the cylinder and normal to the plane of the arm portion 13.

The slide 41 is mounted lon guideways 42 so thatl it can slide in a direction parallel to a plane normal to the axis of'the pivot 40 and the pivot 11. Mounted in fixed position on the arm portion 13 is a reversible piston and cylinder assemblage 45 including a cylinder `46 and a piston 47 reciprocable therein and having a rod 48 connected to the slide 41. Thus, upon operation of the piston and cylinder assemblage 45the entire slide 41, and thereby the assemblage 35, can beshifted parallel to the face of the arm 13. The directionof the guideway` 42 is; such that the-movement of the slide 41 is substantially in the direction of travel of the arm portion 13 .asthe arm is swung about its pivot 11. By shifting the slide 41, the pivot of the piston and cylinder assemblage 35 can be shifted forwardly and rearwardly in the direction of travel of the arm portion 13 duringtheformingoperation.

Referring iirst tothe Figs. 2 through 6, the piece to be formed is shown-as a bumper for an automobile andV of which the center portion must be formed by the embossing die E and the side face die D. In order that the wipe shoe 27 may be brought as closely as possible adjacent to the stretch forming head 39 at the end of the forming stroke, the shoev 27 is providedwith a notch, indicated at 49, which allows the shoe 27 toapproach as near as can be its associated head 39. For this purpose, the self-restoring means 29 described are provided to rotate the wipe shoes Z7 to the properl starting position so that -they can be applied to the stock initially very closely adjacent to the ends ofthel embossing die E. In general, the side face of the die D has its highestpoint at `its mid-portion, this being dictated in generalby the shape of, the part to be made. However, in startingstretch forming of a piece of stock thereon, it is necessary that the.. piece of stock be tangential to, and spaced' above, theA highest point of the die D initially -for the purposeof feeding and obtaining the proper stress on the stock. As illustrated in Fig. 6, a normal position of the stretch assemblies for this purpose would be with the stock in the position indicated by the dottedV line 50. This requires that the axis of the two stretch forming` pistonand cylinder assemblages 35 be parallel; andlie in a common plane-tangent tothe crestyof the side facezof .the'die` D.

If, inthis position the embossing-die and the wipe Ashoes'. 27; `were applied, then-the stock would be deilecteddown wardly -at its-midportion by the die-EV andshoes 27 and:

would assume the position illustrated by the solid line 51. In such an instance, there would be a component of tensioning force directed back upwardly against the embossing die E and the wipe forming shoes 27, which would be very undesirable. On the contrary, it is desirable that, when the embossing die E and the wipe forming shoes 27 are moved into their initial stock engaging position, the stock be tensioned endwise and positioned as indicated by the dot andA dash line 52, in which case it would be partially curved around the crest of the side face'of the die D andbetangential to the side face of the die Dsubstantially at the outermost limits of engagementof the shoes 27 withthe stock in the starting position. However, since each wipe forming assemblage and stretch 4forming assemblage at one end of the die is carried on the same arm, necessarily the proper position for starting could not be achieved as the arms 10 are swung-,to lower the stretch forming pistonz and cylinder assemblage 35 to position to apply a tensioning. force and locate the stock, as. indicated' by thedotf and: dash line S2. Were the stretch forming assemblages35. so positioned, then the wipe forming shoes 27 would `be spaced outwardly beyond the ends of the embossing'die. E when rst applied so that the stock would not be engaged immediately adjacent the embossing die.

It might at irst be assumed that the wipe formingassemblages 21 could be moved a greater angle apart from the stretch forming assemblages 35. However, this. isvr precluded because of the mechanism for operatingtheembossing die E. Furthermore, if an attempt were made to correct the matter in this manner, then by the: time that the wipe forming shoe 27 had reached the end; of the die D, the stretch forming assemblage would be pulling the stock around the sharp corner lat the. end of4 the yforming face of the die D. It is for this reason that` thestretch forming assemblage is mounted on theslideV 41 so that its pivotal axis 40 can be shifted to diterent` positions for a short distance in the direction oftravel.

Referring` again to Fig. 6, it isto be noted that the -normal position of the stretch forming` assemblage 35, if the1 stock wereto be stretched tangent to the highest point of" the face of the die Dpreparatory to applying the embossing die E and the wipe forming shoes 27, would beabove-Y the level indicated by the dot and dash line 35a required for positioning of the assemblage 35 in order to A havethe stock tangent to the side face of the die at theinstantaneous point of contact after the embossing dieand-.thaA wipe shoes are applied. Accordingly, therefore,` with thewipe shoes 27 and the embossing die E in raisedpositiom the stock is clamped at opposite ends by the heads 39` of the assemblages 35 and in that position is in a position-,in which these assemblies have their axes-aligned witheachother and lie in a common plane, as illustrated in/Fig. `5. Thereupon, tension is applied and before the die, Band the wipe shoes 27 are applied to the` stock, the-piston'and* cylinder assemblages 45 are operated to movethe stretch` forming assemblages 35 downwardly in opposite directions to the dotted line .position shown at;35a in Fig. 6.` In this position, the stock is partly stretched` about;the; peak of the side faced die D so that theinstantaneous: line of contact at each side of the center of that face of the side face die is substantially at the point at which it will be engaged by the applied wipeformingshoesi 27. Thus, the embossing die E and the wipe formingshoes-M are'initially applied to thestock after thestock has `been laid onto the side face of the die D sutiiciently far fromY the longitudinal mid-portion of the face so that it isidrectly pressedV against the die face by the die Eand shoes 27, and there is no tensioning component tending. to pull: the stock away from the side face of the die.4

With'the shoes 27 in this position and the embossing. die E applied, thearms 10` are swung in oppostendirections about the axes of the pivots 11so asto` concurrently. stretch formthe stockV about zthe. dieA and wipe` itVv onto the; die-D'.V

However, during this operation, after the stretch forming assemblages 35 have moved downwardly so that the stock at its ends is tangent to the end of the side face, then the piston and cylinder assemblages 45 are operated to shift the pivots 40 of the stretch forming assemblages 35 back toward their starting position so that the angularity, in the direction of swinging, of the wipe forming assemblages 21 and the 'stretch forming assemblages 35 about the axis of the pivots 11, is restored to that which it was originally. By this means, the angularity of the wipe forming shoe 27 of each arm and the stretch forming head 39 thereof about the axis of the pivots 11, may be varied.

Referring to Fig. 7, any suitable means for controlling the operation of the various assemblages in the sequence desired may be provided. For purposes of illustration, applicant has shown merely remote control solenoid operated valves leaving the control of the operation to the manipulation of the valves by the operator. For the purposes of operating the various assemblages, a suitable pump 60 driven by a motor 61 and connected at one side to a sump 62 and at the other side to a pressure line 63, is provided. For operating the embossing assemblage 6, a suitable solenoid operated control valve 65 is connected to the opposite ends of the cylinder 7, as illustrated. This valve may be one of the conventional solenoids operated remote control valves which, in the position illustrated, locks the piston and cylinder assemblage 6 hydraulically and in another position causes the assemblage to move to extended position to apply the embossing die E, and in a third position, causes the assemblage 6 to retract the die E. Correspondingly, the assemblages 15 are connected in parallel to a control Valve 66 which is similar in all respects to the valve 65. The Wipe forming assemblages 21 likewise are connected in parallel to a control valve 67. The stretch forming assemblages 35 are connected to the pump through corresponding control valve 68, and the stretch forming adjustment assemblages 45 are connected through a control valve 69 tothe pump. Thus, by operating the valves 65 through 68 in the sequence desired, the effect desired can be obtained.

Generally, the operation is such that the arms 10 are swung upwardly to starting position in which the piston and cylinder assemblages 35 are such that they can stretch the stock endwise While holding it tangent to the midportion of the die face D. Having thus stretched the stock initially, the assemblages 45 are operated to shift the pivotal axes 40 of the assemblages 35 downwardly, thus to the dotted position illustrated at 35a in Fig. 6. While they are held in this position, the embossing die E is applied and immediately thereafter the Wipe shoes 27. With the die E and wipe shoes 27 in initial contact position, the assemblages are operated to swing the arms 10 downwardly, thus eii'ecting the combined wipe and stretch forming operation while the central portion of the stock is held by the embossing die. When the stock reaches the end of the side face and is tangent thereto, the piston and cylinder assemblages 45 are operated to restore the pivotal axes 40 to their starting position. If desired, this operation can be delayed until after the piece has been removed.

Having thus described my invention, I claim:

l. In a combined wipe and stretch forming machine, a frame, a side face die mounted thereon, a carrier pivotally connected to the frame for swinging about a predetermined axis on a forming stroke, a wipe forming assemblage mounted on the carrier including a wipe shoe yieldably urged thereby toward the side face of the die, a stretch forming assemblage mounted on the carrier and including a stretch forming head yieldably urged thereby endwise of the side face, said shoe and head being positioned so ythat the head is ahead of the shoe in the direction of travel as the carrier moves on its forming stroke, power means for the assemblages, respectively, means supporting the stretch forming assemblage on the carrier for movement along a path such that the distance at which the head precedes the shoe in the direction of travel on the forming stroke is varied, and power means for moving the stretch forming assemblage along said path.

2. A machine according to claim l including a pressure forming die cooperable with the face of the side face die in spaced relation to the ends of the side face die, and positioned with one end substantially engaging the adjacent end of the wipe shoe in the starting position of the carrier and forming position of the pressure forming die.

3. A machine according to claim 1 including a carrier having a guide rotatable with the cam'er about said predetermined axis, a rigid cooperable guide on the frame accommodating the guide on the carrier and constraining the carrier to move in a path parallel to a plane normal to said predetermined axis.

4. In a combined wipe and stretch forming machine, a frame, ya side face die mounted thereon, a carrier pivotally connected to the frame for swinging about a predetermined axis on a forming stroke, a wipe forming assemblage mounted on the carrier, a wipe shoe carried and yieldably urged thereby toward the side face of the die, a stretch forming assemblage, a pivot means securing the stretch forming assemblage to the carrier for swinging about an axis parallel to, and oset from, the predetermined axis, a stretch head connected to the stretch forming assemblage and yieldably urged thereby endwise of the stock and die face, said shoe and head being positioned so that the head is ahead of the shoe in the direction of travel as the carrier is swung on its forming stroke, power means for the assemblages, respectively, additional power means to swing the carrier on its forming stroke, means connecting the pivot means to the carrier for movement, relative to the carrier, transversely of its pivotal axis Iin opposite directions, generally endwise of `the path of travel of the carrier, to different positions relative to the carrier, to change the distance by which 0 the stretch head precedes the wipe shoe, and auxiliary power means to move the pivot means to said positions, selectively.

References Cited in the tile of this patent UNITED STATES PATENTS 1,324,940 Theberath Dec. 16, 1919 1,461,471 Bancroft July 10, 192.3 2,880,780 Mackey Apr. 7, 1959 2,903,038 Gobefr Sept. 8, 1959, 2,920,676 'Illrnblade Ian. 12, 1960 FOREIGN PATENTS 494,702 Germany Mar. 27, 1930

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