US3023800A - Metal bending machine - Google Patents

Description

March 6, 1962 J. M. WHITE ET Ai.

METAL BENDING MACHINE 3 Sheets-Sheet 1 Filed Jan. '7, 1959 March 6, 1962 J. M. WHITE EI'AL 3,

METAL BENDING MACHINE Filed Jan. 7, 1959 s Sheets$heet 2 EEE '7.

March 6, 1962 J. M. WHITE ETAL 3,023,300

METAL BENDING MACHINE Filed Jan. '7, 1959 3 Sheets-Sheet 3 I28 I32 I34! 71 Mm INVENTORS ATTORNEY United States Patent 9 3,023,800 METAL BENDING MACHINE James M. White, Jack W. Cardwell, Robert F. Davissou, and Ralph P. Brooks, Knoxville, Tenn., assignors to Greenway Industries, Knoxville, Team, a partnership Filed Jan. 7, 1959, Ser. No. 785,393 8 Claims. (Cl. 153-56) This invention relates generally to sheet metal bending or forming machines and more particularly provides an improved machine capable of forming into not only flat curved shapes strip and sheet metal but also metal having an angular cross section while automatically varying the curvature during the forming operation.

The prior art provides machines for bending strip or sheet metal which employ feed rolls to pass the work toward an adjustable roll that forms the metal to a predetermined radius of curvature. Such machines, however, are incapable of varying the curvature of the metal during the forming pass so as to produce sheet bent into a noncircular on noncylindrical form. Nor are such machines capable of forming strip metal having an angular cross section since the angle flange cannot be accommodated between the feed rolls without deformation of either the rolls or the metal flange.

Accordingly, it is a primary object of this invention to provide an improved machine capable of automatically forming both angle section and fiat sheet metal into either circular or noncircular shape.

Another object of the invention is to provide a metal rolling machine employing a pair of driven feed rolls with a forming roll, whose axis is pivoted about one of the feed rolls, together with means for automatically moving the forming roll so as to vary the curvature of the work metal during the forming pass.

A further object of the invention is to provide a metal rolling machine of the character indicated in which the variation of curvature in the work metal is obtained by means of an oscillating or revolving cam, operated from the single source of power for the feed rolls through an adjustable speed reducer and linkage including a rocker shaft, which is effective to move the forming roll about one of the feed rolls during the work pass.

Yet another object of the invention is to provide a metal rolling machine of the character indicated in which, in addition to the speed reducer for controlling the cam movement and hence the rate of change of curvature in the formed work, the linkage between such reducer and cam is also adjustable so as to vary the cam movement in accordance with the length of metal to be formed.

Still another object of the invention is to provide a metal rolling machine employing a pair of driven feed rolls and a forming roll in which at least one of the rolls is circumferentially grooved to accommodate the flange of an angle section work strip during its pass between the feed rolls and to prevent twisting thereof during the forming operation.

A further object of the invention is to provide a metal rolling machine capable of forming metal strip of relatively great length into complex shape of varying curvature, and whose feed and forming rolls are assembled in sections transverse to their axes or otherwise separated or slotted to accommodate work strips of angle section.

A still further object of the invention is to generally improve and simplify metal rolling or bending machines.

The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of specific embodiments when read in connection with the accom- 7 screws 24 are ice panying-drawing, wherein like reference characters indicate like parts throughout the several figures and in which:

FIGURE 1 is a view in front elevation of a machine constructed in accordance with the invention;

FIG. 2 is a side elevation of the machine with a portion of a roll bearing side wall broken away to reveal interior details;

FIG. 3 is a cross section taken on the line 33 of FIG. 2;

FIG. 4 is an enlarged fragmentary section through the feed rolls of the machine showing a work strip of angle section being passed therethrough;

FIG. 5 is a plan view of an article of manufacture whose frame is adapted to be formed in the machine of FIGS. 1-4;

FIG. 6 is a sectional view taken on the line 66 of FIG. 5 and looking in the direction of the arrows;

FIG. 7 is a diagram fragmentarily showing the relative positions of the forming and feed rolls and the cam control elements at a certain instant during a work pass;

FIG. 8 is a diagram similar to FIG. 7 but showing the relationship of the elements at a different instant during a work pass;

FIG. 9 is a diagram similar to FIGS. 7 and 8 illustrating the effect of different adjustments of the cam operating linkage;

FIG. 10 is a fragmentary elevation of a machine detail illustrating the method of locking the cam so as to fix the forming roll and produce shapes of circular outline;

FIG. 11 is a fragmentary elevational view showing a modified cam which may be used in the machine of FIGS. 1-4; and

FIG. 12 is a side elevation of a modified roll which may be used in the machine.

Referring now to the drawings in detail, the main support frame, of the machine shown in FIGS. 1-3, comprises a skeleton table 19 and legs 12 upon which are suitably mounted roll bearing side walls 14 and 16. The parallel rolls 28 and 30 constitute feed rolls and define a pass through which is fed the metal sheet or angle strip 11,.FIGS. 3 and 4. The roll 32 is a bending or forming roll movable with respect to the feed rolls. Means are provided whereby the upper feed roll 28 may be adjusted with respect to the lower feed roll to obtain the desired spacing and pressure in accordance with the gauge of the .metal being formed, and whereby the third or bending roll 32 may be adjusted with respect to the roll pass to obtain the desired curvature of the formed metal. These means include slots or guideways 18 in the upper edges of Walls 14 and 16 for mounting the bearing blocks 20 which support the bearings for the ends of shaft 36 for the roll 28. The shaft 38 of the lower feed roll 30 is journaled in a pair of fixed bearing blocks 22. Adjusting threaded through the bearing braces 26 and are connected at their inner ends to the blocks 20. By adjusting these screws the desired feed roll setting may be obtained. The forming roll 32, which is an idler roll, is mounted to rotate about spindles 49 carried by a pair of triangular members or plates 34 near one corner thereof. The plates 34 are in turn pivotally mounted near a second corner to move about one of the feed roll shafts, such as the lower shaft 38. The means for moving the bending roll 32 include a cam follower 46, which may be in the form of a wheel, whose circumference may be grooved if desired, journaled on a stub shaft 48 projecting from the third corner of each plate 34. The mechanism for controlling the movement of cam follower 46 will be described later herein. At least one of the described rolls is provided with one or more transverse grooves or slots 29 which are adapted to accommodate flanges on the work material.

.The machine is preferably powered by a single electric motor, such as indicated at 60, mounted on table at one side of the rolls. The output of motor 60 is transmitted to the feed rolls through a conventional speed reducer 62 having a small output gear 64 meshing with a large gear 66 which is keyed to shaft 38 of the lower feed roll 30. A second, smaller gear 68 on shaft 38 transmits power to drive the upper feed roll 28 through gear 70. Since the vertical adjustment of feed rolls 28 and 30 is relatively small, the gears 68 and 70 will always remain in mesh.

The power for moving the forming roll 32 is also preferably taken from the single power source, which is the motor 60. The output shaft of speed reducer 62 is provided with a gear sprocket 72 (FIG. 2) which is flexibly linked by a chain 76 with a sprocket 74 keyed to the input shaft of a second speed reducer 78. The speed reducer 78 is of a conventional type capable of adjustment to yield variable speeds at its output shaft 82. For this purpose an adjustment knob 80 is provided at one side of the speed reducer accessible to the operator. An indicator 79 is visible at the front of speed reducer 78 to show the adjusted speed for which the device is set. The speed reducer 78 is supported in any suitable way under the skeleton table 10, as by means of a platform 81 hung by struts.

A rocker or cam shaft 94 is journaled in bearings 95, '97 and 99 above the table 10 so as to oscillate on its axis which parallels feed roll shafts 36 and 38. Movement is imparted to cam shaft 94 by means of a link 88 which passes through an opening in table 10 and is pivotally connected at its ends to the crank arms 90 and 84 respectively fixed to the cam shaft 94 and output shaft 82 of the speed reducer by means of collars 92 and 85. The crank arm 84 is longitudinally slotted at 86 to provide adjustment of its effective length by the nut 87 threaded on the crank pin which forms the lower pivot of link 88.

A pair of collars 96, FIG. 1, are fixed in'spaced relation to each other on cam shaft 94 under the forming roll 32. A cam 98, which may be in the simple form of a thin plate having an arcuate edge 106, FIGS. 2 and 3, is bolted as at'101 to each collar 96. The arcuate edges 106 are adapted to engage the cam followers 48 and "to elevate or lower plates 34 with turning movement about roll shaft 38 upon rotation of the cam shaft.94. Such pivotal movement of plates 34 carries the forming roll 32 across the path of the work pass and toward or away from the upper feed roll 28. To vary the radius of curvature being applied to the metal being worked by the forming roll, the curved edges 1060f cams 98 are preferably formed with a central portion having little curvature; the curvature of the end portions being gradually increased toward the outer ends of the cam.

One of the collars 96 is preferably provided with a locking projection 100 having an aperture 102 .for reception of a locking member such as the threaded clevis rod 126, FIG. 10. The rod may be inserted throughan opening in a bracket 104 fixed to the table 10. A bolt 127 is .passed through the clevis end of rod 126 and through opening 102 to hold the cam 98 in any desired position. The lock nuts 130 adjustably clamp the rod 126 to the bracket 104. When the cams 98 are locked in agiven position, by fastening the rod 126 to the locking projection 100, the forming roll 32 will idle around a stationary axis, so as to form the work into a circular or cylindrical shape with a fixed radius of curve. During such an operation, the link 88 is disconnected from crank arms 90 and 84 to prevent rotation of the rocker shaft '94.

An additional idler roll 42 is provided at the rear of the machine and journaled between the walls 14 and 16 so that its axis 44 is parallel to the axes of the .feed rolls 28 and 30. The roll 42 supports and guides the work being fed into the pass between the rolls 28 and .30. To assist in alignment of the work metal edge, a vertical guide roller 50 is journaledin a bracket-52 supported from the wall 16 at the rear of the machine. A similar,

but inclined roll 54 is journaled n th g sk a the front of wall 16 to guide the work metal as it reache the front of the machine. The blacket 56 15 mounted on a support 59, which in turn is Secured to Wall 16 by suitable means such as the bolts 58. The suPP 59 can be removed from wall 16 and attached to the wall 14 so as to guide the work pass through 1 a l a .along its other edge. Similarly, the guide roll may P mQved to the other side of the machine, or addit lp l guide Toners may be permanently afiixed there.

The operation of the machine will be qeswbed m relation to the forming of a typical specific objf p l as the frame 11 illustrated in FIGS. 5 and 6 on egre l reduced scale. The frame 11 encloses an illuminad fl elliptically-shaped sign such as those in common use in outdoor installations, notably at filling stations to advertise gasoline products. These signs are generally of considerable size varying in axial length from about 6 feet to as much as 22 feet. Sometimes the signs are circular rather than elliptical. The elliptical signs are comprised of a pair of elliptical translucent plates 120 formed of a plastic, such as methyl methacrylate, and bearing indicia, not shown. Each plate 120 is held between the flnges 13 of the frame 11. The frame is F-shaped in cross section so as to provide two spaced parallel flanges 13 at right angles to the web of the frame. To permit assembly of the plates 120, each frame 11 is formed in half sections, i.e., semi-ellipses between which a plate 120 is placed. The frame sections are butted and welded to each other or more generally to the closure member 122, which is thin sheet metal wrapped around both frames to conform to the shape thereof. The interior of the sign thus assembled houses illuminating means,- not shown.

The forming of a semielliptical portion of frame 11 may, for example, require the shaping of an 18-footlengtl1' of metal, of extruded F-shape cross section, into an ap= proximately 11-foot length half ellipse. The machine provided by the present invention is prepared for this operation by setting the cam 98 at its center; i.e., at about the position shown in FIG. 2. The speed reducer 78 is adjusted by means of knob to rotate its output shaft 82 one turn for the number of turns of the feed rolls 28 and 30 required to move the work 18 feet, i.e., the peripheral length of the semiellipse to be formed. The power is then turned on to operate motor60 causing the 18-foot angle extrusion 11 to be fed between the rollers 28 and 30 from the rear with one edge of the extrusion guided by roller 50 and the web supported and guided by roller 42. The flanges 13 of the work metal are received in the grooves 29 of the upper feed roll 28 as best shown in FIG. 4. When the motor 60 starts, the cam 98,- controlled by the link 88 and crank arm 84, begins to turn in the direction of the arrow shown in FIG. 3. As a result of the movement of the cam follower 48 on the arcuate edge 106 of the earn, the forming roll 32 will be elevated at first slowly and then more rapidly as the end of the cam is approached. This will cause the forming roll to bend the frame member 11, at first, to a largeradius of curvature, and progressively, to a smaller and smaller radius of curvature. This forming action is illustrated diagrammatically in FIGS. 7 and 8. FIG. 7 shows the position of the cam '98 and its direction of movement as the cam follower 46 approaches one end of the cam. The work metal '11 has already been formed with little curvature, practically a straight line, at the beginning of the pass and an ever increasing curvature as thecam follower ap proaches the cam end. As the crank arm 84 continues to turn clockwise, the crank arm on cam shaft '94 will come to a stop and then reverse direction. As shown in FIG. 8, the cam follower 46 will then move back from the outer end of the cam 98 toward the center. During this reverse movementof the follower, the roll '32 will be lowered, at first rapidly and then progressively more slowly. This will completethe bending er the-frame 11 into a half ellipse with the cam follower coming to rest at the center of cam 98. This operation may be repeated four times to form the sections needed to frame the sign of FIGS. 5 and 6. Four individual lengths of 18- foot angle section, metal strip are thus passed through the machine separately and as each length feeds, the cam 98 oscillates through an arc of approximately 90, in one direction and then in the reverse direction, to raise and lower forming r011 32 at varying rates and produce the semielliptical shape required.

If it is desired to form an ellipse of different length and curvature, the speed reducer 78 may be adjusted so that its output shaft revolves once during the pass of the new length of material to be formed. An additional adjustment may be made in the crank arm 84, which may be effectively shortened or lengthened by loosening the nut 87, sliding the crank pin in slot 86 to another point, and retightening the nut 87. As diagrammed in broken lines in FIG. 9, the crank pin or pivot of link 88 will then have a smaller locus, circle 114 rather than the circle 110. As the crank arm 84 makes one revolution, the crank pin connecting link 88 to crank arm 90 will then describe a shorter are, 116 rather than 112. Thus, the arc of rotation of the cam shaft 94, and hence of the cam 98, is shortened when the crank arm is adjusted to a shorter length. Consequently, the movement of the forming roll 32 will be changed to reduce the difference in the radius of curvature being formed in the work.

If it is desired to form the work with a constant radius of curvature, the cam 98 is set at a position which will yield the desired curvature and is fastened in such position by the means shown in FIG. 10. As previously explained, the locking rod 126 is inserted through the opening in the lug 104 and adjusted so that its clevis end may be bolted to the projection 100 carried by the collar 96. When the cam is so fastened, it is necessary to disconnect the link 88 so that rotation will not be imparted from the speed reducer output shaft 82 to the cam shaft 94.

If it is desired to form the half of the ellipse alternate to that shown in FIG. 8; i.e., a semiellipse with a short radius of curvature portion at each end and a large radius of curvature in the center, the cam 108 shown in FIG. 11 may be substituted for cam 98. The cam 108 has an arcuate surface 106 similar to that of cam 98 but at one end the surface 106 is abruptly merged into the surface portion 110. The cam follower 46 is seated at the end of cam 108 on surface 110, and the speed reducer and crank shaft 84 are so adjusted that the cam shaft 94 will turn approximately or just slightly more than 180 for one pass of the work material. Upon starting the machine, the cam follower 46 moves quickly from the surface 110 to surface 106 at the beginning of the work pass. Thus, the forming roll 32 will be quickly elevated to form the Work material into the desired shape having a short radius of curvature at the beginning and with gradually increased curvature until the cam follower reaches the center of cam 108. As the cam continues to rotate in the same direction, the curvature is first gradually and then rapidly decreased until the cam follower stops on the end of cam 108. In utilizing the substitute cam 108, the speed reducer output shaft turns 180 during the work pass, and during the subsequent half turn the cam reverses direction and returns to its starting position. After forming, it may be necessary or desirable to cut off the short piece of nonelliptic shape formed while the cam follower is on surface 110 of earn 108.

In FIG. 12 is shown a modified roll which may be substituted for one of the feed rolls 28, 30 and if desired for the forming roll 32. The modified roll is comprised of cylindrical sections indicated at 128, 130, 132, 134, 136, and 138, all of different widths. The sections may be slipped onto the shaft 36, having a longitudinal key 37, to assemble a roll of any width and to provide grooves between the sections at desired locations for accommodating the flanges of the metal to be formed. The roller can thus be used to work metal of any width and angle cross section since the feed roll sections can be spaced to accommodate different spacings and thicknesses of the angle. metal flanges. It is also evident that the provision of the spaces between the roll sections, as previously described in connection with the grooves 29 of the roll 28, serve to restrain the Work from twisting as it passes through the machine.

It will be apparent from the above description that the improved machine permits the forming of sheet and strip metal including metal having angular cross sections. The machine is capable of forming long lengths of metal angle strip into complex, noncircular, curved shapes as well as circular shapes. The radius of curvature may be automatically varied during the work pass by preadjustment of the speed reducer and length of its crank arm. In addition, cams of different shapes, or cranks and links of different lengths, may be substituted to form the metal into a limitless variety of curves.

Although certain specific embodiments of the invention have been shown and described, it is obvious that many modifications thereof are possible. The invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

We claim:

1. In a machine for bending angle section strip material into curved form, the combination of a pair of elongated cylindrical, axially parallel, feed rolls adapted to pass a strip between them, a forming roll whose axis is parallel to the axes of the feed rolls and which is pivotally supported with respect thereto so as to swing about a line parallel to the axis of one feed roll, one only of said feed rolls being formed of separate cylindrical sections of different widths mounted on a longitudinally keyed shaft and adjustable longitudinally of the shaft to provide groove-like spaces in the roll at any desired locations conforming in shape to a flange of said strip and embracing both sides of the flange to prevent twisting of the strip during the forming pass, power means for driving said feed rolls, and means for automatically moving said forming roll during the work pass to vary the radius of curvature of the strip being passed by the feed rolls.

2. In a machine for bending angle section strip material into curved form, the combination of a pair of driven feed rolls adapted to pass a strip between them, a forming roll mounted between members pivoted to one of said feed rolls and movable with respect to the feed rolls to engage the strip and vary the radius of curvature of the strip being passed by the feed rolls, one of said feed rolls being provided with a circumferential groove conforming in shape to a flange of said strip and embracing the flange to prevent twisting of the strip during the forming pass, means for driving said feed rolls, and means for automatically moving said forming roll with respect to the feed rolls during pass of the strip, said last named means including a rocker shaft having a cam, means for oscillating said cam in proportion to the feed of the work being formed, a follower carried on one of said pivoted members to follow said cam and vary the position of the forming roll, a variable speed reducer connected to said means for driving the feed rolls, a crank on the output of said speed reducer, a crank on said rocker shaft, and a link pivotally connected to said cranks.

3. A machine for bending sheet material according to claim 2 wherein one of said cranks is provided with means for adjusting its length whereby to vary the length of the arc of rotation of said rocker shaft and cam.

4. A machine for bending sheet material according to claim 3 wherein said means for adjusting the crank length comprises a longitudinal slot in the arm of said crank on said variable speed reducer, a crank pin on said link slidable in said slot, and a nut on said pin to fasten the link to the crank arm at any desired point to effectively vary the length of the crank arm.

' 75 machine for bending sheet material according to 7 claim 2 wherein additional means is provided for locking said rocker shaft to permit forming the work stripinto a shape having a constant radius of curvature.

'6. In a machine for bending strip material into curved form, the combination of a pair of driven feed rolls adapted to pass a strip between them, a forming roll movable with respect to the feed rolls to engage the strip and vary the radius of curvature of the strip being passed by the feed rolls, means for driving said feed rolls at a given speed, and means for automatically moving said forming roll with respect to the feed rolls during pass of the strip, said last named means including a rocker shaft having a cam, means for oscillating said cam at a speed in proportion to said given speed of 'the feed rolls, a. follower secured to said forming roll to follow said cam and vary the positionof the forming roll, and'adjustable means for varying the speed of rotation of said cam with respect to said given speed of the feed rolls whereby lengths'of strip material may be formed into shapes of dilferent curvature.

7. In a metal working machine, a pair of rolls adapted to pass a strip between them, means for advancing a strip of stock to pass between said rolls at a given speed, a forming roll operable to engage the strip beyond the pass to bend the strip into curved form, means including a rotatable cam for automatically moving the forming roll with respect to said pair of rolls to vary the radius of curvature imparted to the strip during its pass, and adjustable means for varying the speed of rotation of said cam with respect to the said given speed of advance of the strip through the feed pass whereby various lengths of stock may be formed into shapes of different curvature.

8. In a metal working machine, the combination set forth in claim 7 wherein said means for varying the speed of rotation of said cam comprises a source of power for driving said pair of rolls and a variable speed reducer whose input shaft is also connected to said source of power and whose output shaft is connected to drive said cam.

References Cited in the file of this patent UNITED STATES PATENTS

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