Device for Forming Conical Sections

Abstract

A roll forming machine includes a frame supporting a conical drive roll rotatable on a fixed axis, and a conical pinch roll rotatable and movable transversely and angularly toward and away from the drive roll. Transversely movable and angularly adjustable forming rolls are disposed on opposite sides of the pinch and drive rolls, operable to selectively bend a workpiece frictionally held between the pinch and drive rolls and moved by their counter-rotation. The drive and pinch rolls rotate the workpiece about a transverse axis as they move the workpiece through the machine, enabling a consistent and accurate bending of workpieces to desired conical geometries. The machine can employ elongate drive and pinch rolls with guides to selectively place the workpieces along the rolls, to controllably vary the ratio of small-end to large-end radii in shaped pieces. Alternative versions feature a single forming roll, and rolls that alternatively serve the pinching and forming functions.

1 . A roll forming machine, including:
 an elongate first roll having a first roll axis and substantially uniformly tapered over a first region extending axially between a first axial location having a first diameter and a second axial location having a second diameter larger than the first diameter;   an elongate second roll having a second roll axis and substantially uniformly tapered over a second region extending axially between a third axial location having a third diameter and a fourth axial location having a fourth diameter larger than the third diameter;   an elongate third roll rotatable on a third roll axis; and   a roll mounting structure coupled to the first and second rolls to support the first and second rolls in side-by-side relation for rotation about the first and second roll axes, respectively; with the first axial location proximate the third axial location and the second axial location proximate the fourth location; and with the first and second rolls inclined relative to one another whereby the first and second roll axes intersect and first and second confronting surfaces of the first and second regions extend longitudinally, separated by a substantially constant transverse spacing to facilitate a frictional hold of a uniformly thick workpiece between the first and second regions with a major plane of the workpiece perpendicular to an alignment plane containing the first and second roll axes;   wherein the roll mounting structure is operable to counter-rotate the first and second rolls about the first and second axes respectively during said frictional hold, thereby to effect a rotation of the workpiece about a transverse rotational axis lying in the alignment plane; and   wherein the roll mounting structure further is coupled to support the third roll in side-by-side, transversely spaced apart relation to the first and second rolls, and is operable to selectively move the third roll transversely relative to the first and second rolls to apply a predetermined bending force to the workpiece during said hold and rotation.   
     
     
         2 . The machine of  claim 1  wherein:
 the second roll is movable transversely relative to the first roll to selectively adjust the transverse spacing. 
 
     
     
         3 . The machine of  claim 2  further including:
 a workpiece alignment component adapted to facilitate locating a leading edge region of a workpiece between the first and second rolls in a predetermined initial position for said hold. 
 
     
     
         4 . The machine of  claim 3  wherein:
 the workpiece alignment component comprises a stop positioned to abut the leading edge region as the workpiece is inserted transversely between the first and second rolls, to prevent further transverse movement of the workpiece beyond the predetermined initial position. 
 
     
     
         5 . The machine of  claim 4  wherein:
 the workpiece alignment component further includes a guide member positioned to contact a side edge of a workpiece as the workpiece is inserted between the first and second rolls, to determine a longitudinal location of the workpiece with respect to the first and second rolls. 
 
     
     
         6 . The machine of  claim 5  wherein:
 the stop and the guide member are retractable away from the first and second rolls after movement of the second roll transversely toward the first roll to effect said hold. 
 
     
     
         7 . The machine of  claim 3  wherein:
 the workpiece alignment component comprises a first side edge contact feature positioned to contact a side edge of a workpiece as the workpiece is inserted between the first and second rolls to determine a first longitudinal location of the workpiece with respect to the first and second rolls, and a second side edge contact feature spaced apart longitudinally from the first contact feature and positioned to contact the side edge of the workpiece as the workpiece is inserted between the first and second rolls, to determine a second longitudinal location of the workpiece with respect to the first and second rolls. 
 
     
     
         8 . The machine of  claim 1  further including:
 a fourth roll rotatable on a fourth roll axis, wherein the roll mounting structure further is coupled to the fourth roll to support the fourth roll in side-by-side, transversely spaced apart relation to the first and second rolls on an opposite side of said alignment plane from the third roll; 
 wherein the roll mounting structure further is operable to selectively move the fourth roll transversely relative to the first and second rolls to apply the predetermined bending force to the workpiece during said hold and rotation. 
 
     
     
         9 . The machine of  claim 1  wherein:
 the third roll has a substantially uniform diameter over its entire length. 
 
     
     
         10 . The machine of  claim 1  further including:
 a first motive power source operatively coupled to the first roll for rotating the first roll about the first roll axis. 
 
     
     
         11 . The machine of  claim 1  wherein:
 the confronting surfaces of the first and second rolls are inclined from the first and second roll axes respectively at an angle within the range of one to five degrees. 
 
     
     
         12 . The machine of  claim 1  wherein:
 the first and third diameters are substantially equal, and the second and fourth diameters are substantially equal. 
 
     
     
         13 . An apparatus for shaping substantially planar sheet metal panels into truncated conical wall sections for a drum, including:
 a first elongate truncated conical roll having a first roll axis;   a second elongate truncated conical roll having a second roll axis;   a roll mounting structure coupled to the first and second rolls to support the first and second rolls in side-to-side relation, tapered in the same direction, and inclined such that the first and second roll axes intersect and confronting first and second surface portions of the first and second rolls, respectively, extend longitudinally and are separated from one another by a substantially uniform transverse spacing;   a power component operatively coupled to the first roll for counter-rotating the first and second rolls about the first and second roll axes respectively with a substantially planar formable sheet metal panel frictionally held by a thickness thereof between the first and second confronting surface portions, to rotate the panel about a transverse rotational axis lying in an alignment plane defined by the first and second roll axes; and   a panel bending component operable to apply a controlled bending force to the panel substantially in the direction of said thickness while the panel is so held and so rotated.   
     
     
         14 . The apparatus of  claim 13  wherein:
 the panel bending component comprises an elongate third roll rotatable on a third axis, wherein the roll mounting structure supports the third roll in side-by-side transversely spaced apart relation to the first and second rolls with the third roll axis directed substantially longitudinally, and is operable to selectively move the third roll transversely relative to the first and second rolls to apply the bending force. 
 
     
     
         15 . The machine of  claim 14  wherein:
 the panel bending component further comprises a fourth roll rotatable on a fourth roll axis; 
 the roll mounting structure further supports the fourth roll in side-by-side, transversely spaced apart relation to the first and second rolls with the forth axis directed substantially longitudinally and on an opposite side of said alignment plane from the third roll; and 
 the roll mounting structure further is operable to selectively move the fourth roll transversely relative to the first and second rolls to apply the bending force. 
 
     
     
         16 . The apparatus of  claim 13  wherein:
 the second roll is moveable transversely relative to the first roll to selectively adjust the transverse spacing. 
 
     
     
         17 . The apparatus of  claim 16  wherein:
 the power component further is operatively coupled to the second roll to simultaneously rotate the first and second rolls in opposite angular directions. 
 
     
     
         18 . The apparatus of  claim 16  further including:
 an alignment component adapted to facilitate locating a leading edge region of a panel between the first and second rolls in a predetermined initial position for said hold. 
 
     
     
         19 . The apparatus of  claim 18  wherein:
 the alignment component comprises a stop positioned to abut the leading edge region as the panel is inserted transversely between the first and second rolls, to prevent further transverse movement of the panel beyond the predetermined initial position. 
 
     
     
         20 . The apparatus of  claim 19  wherein:
 the alignment component further includes a guide member positioned to contact a side edge of a panel as the panel is inserted between the first and second rolls, to determine a longitudinal location of the panel with respect to the first and second rolls. 
 
     
     
         21 . The apparatus of  claim 20  wherein:
 the stop and the guide member are retractable away from the first and second rolls following movement of the second roll transversely toward the first roll. 
 
     
     
         22 . The apparatus of  claim 18  wherein:
 the alignment component comprises a first guide member positioned to contact a side edge of a panel as the panel is inserted between the first and second rolls to determine a first longitudinal location of the panel with respect to the first and second rolls, and a second guide member spaced apart longitudinally from the first guide member and positioned to contact the side edge of a panel as the panel is inserted between the first and second rolls, to determine a second longitudinal location of the panel with respect to the first and second rolls. 
 
     
     
         23 . A process for forming planar malleable panels according to conical geometries, including:
 a. providing a conical drive roll and a conical pinch roll rotatable about respective drive roll and pinch roll axes and inclined relative to each other whereby said axes intersect to define an alignment plane, with first and second confronting surfaces of the drive and pinch rolls, respectively, extending longitudinally and separated from one another by a substantially uniform transverse spacing;   b. providing a substantially planar and uniformly thick panel formed of a malleable material with oppositely inclined leading and trailing edges, substantially parallel side edges, and a leading edge region adjacent to and incorporating the leading edge;   c. positioning the panel with the leading edge region disposed between the first and second confronting surfaces, with a major plane of the panel perpendicular to the alignment plane, and with the leading edge extending longitudinally;   d. with the panel so positioned, transversely moving at least one of the drive roll and the pinch roll to reduce the transverse spacing to effect a frictional hold of the panel between the drive roll and the pinch roll;   e. during the frictional hold, counter-rotating the drive roll and the pinch roll to rotate the panel about a transverse rotational axis perpendicular to the alignment plane; and   f. while so rotating the panel, applying a controlled bending force to the panel in a direction substantially perpendicular to the major plane.   
     
     
         24 . The process of  claim 23  wherein:
 positioning the panel comprises placing the leading edge of the panel against a stop positioned between the drive roll and the pinch roll. 
 
     
     
         25 . The process of  claim 23  wherein:
 positioning the panel comprises disposing one of the side edges of the panel against a first guide member disposed proximate the drive roll and the pinch roll. 
 
     
     
         26 . The process of  claim 23  wherein:
 positioning the panel comprises disposing one of the panel side edges against a selected one of a plurality of longitudinally spaced apart guide members disposed proximate the drive roll and the pinch roll, thereby to select one of several alternative longitudinal locations of the panel with respect to the drive roll and the pinch roll. 
 
     
     
         27 . The process of  claim 23  wherein:
 transversely moving at least one of the drive roll and pinch roll comprises moving the pinch roll toward the drive roll. 
 
     
     
         28 . The process of  claim 23 wherein:
 counter-rotating the drive roll and the pinch roll comprises coupling a source of motive power to rotate the drive roll about the drive roll axis, while rotating the pinch roll about the pinch roll axis by virtue of its frictional coupling to the drive roll through the panel.   
     
     
         29 . The process of  claim 23  wherein:
 counter-rotating the drive roll and the pinch roll comprises coupling a first source of motive power to rotate the drive roll about the drive roll axis and coupling a second source of motive power to rotate the pinch roll about the pinch roll axis, to rotate said rolls in opposite angular directions and at the same angular speed. 
 
     
     
         30 . The process of  claim 23  wherein:
 applying a controlled bending force comprises supporting an elongate first bending roll for rotation about a substantially longitudinal first bending roll axis in transversely spaced apart relation to the drive roll and the pinch roll on a first side of the alignment plane, and moving the first bending roll transversely against the panel to apply the bending force. 
 
     
     
         31 . The process of  claim 30  wherein:
 applying the bending force further comprises supporting a second bending roll with a substantially longitudinal second bending roll axis in transversely spaced apart relation to the drive roll and the pinch roll on a second and opposite side of the alignment plane, and moving the second bending roll transversely against the panel to apply the bending force. 
 
     
     
         32 . The process of  claim 23  further including:
 repeating steps b. through f. several times to form a plurality of frusto-conically shaped panels, each with arcuate first and second opposite edges having respective first and second different radii and encompassing an arc of less than 360 degrees; 
 assembling the panels end to end with the leading and trailing edges of adjacent panels contiguous, to from a continuous frusto-conical wall section encompassing 360 degrees; and 
 with the panels so assembled, bonding the contiguous leading and trailing edges to form an integral frusto-conical wall section.