Vertical air compliant hemming head

Abstract

The present invention pertains to a hemming head for performing a hemming operation which comprises a support housing adapted for securement to a robot arm on a first end, and having a first roller rotatably secured to a second end. The first roller has a cylindrical body, a head, and a groove between the body and head. The head has a diameter greater than the body, and the groove has a diameter less than the body. The groove also includes a canted surface that conjoins with the head. In use, the cylindrical body is adapted to engage and force a workpiece edge downwardly to a first position and the canted surface is adapted to engage and force the workpiece from the first position to a second position.

1 . A method for roller hemming together the edges of at least two metal panels to form an edge-hemmed connection between the panels, the steps of the method comprising:
 positioning the edges in mated faced engagement on a support frame, the edge of the first metal panel engaging the edge of the second metal panel such that the edge of the first metal panel forms a flange portion that extends beyond the mated edge of the second metal panel;   providing a hemming apparatus having a first roller, a second roller, and a break plate, the break plate being associated with the first roller, the first roller having a first canted surface, and the first and second rollers being rotatably secured to the hemming apparatus;   manipulating the hemming apparatus in a manner that the first roller and the break plate engage opposite sides of the first metal panel and form a bend line on the flange portion by moving the first roller and the break plate along the length of the mated edges of the metal panels wherein the flange portion of the first metal panel is folded over in a gradual bend to form the bend line; and   manipulating the hemming apparatus in a manner that the second roller engages the flange portion and moves along the length of the mated edges of the metal panels in at least one successive pass to force the flange portion to bend about the bend line toward and into engagement with the second metal panel to form an edge-hemmed connection between the panels.   
     
     
         2 . The method of  claim 1  wherein the second roller includes a cylindrical outer surface that engages and forces the flange portion downwardly during one of the at least one successive passes along the length of the mated edges. 
     
     
         3 . The method of  claim 2  wherein the second roller includes a head portion having a canted surface that engages and forces the flange portion downwardly during one of the at least one successive passes along the length of the mated edges. 
     
     
         4 . The method of  claim 3  which comprises manipulating the hemming apparatus in a manner that the canted surface of the second roller moves from a first angular position with respect to the mated edges of the metal panels to a second angular position with respect to the mated edges of the metal panels, and wherein, while the second roller is in the second angular position, the second roller engages and forces the flange portion downwardly and against the second metal panel during one of the at least one successive passes along the length of the mated edges to form an edge-hemmed connection between the panels. 
     
     
         5 . The method of  claim 4  wherein the hemming apparatus comprises a cam structure to selectively move the break plate between an open position and an engaged position, and the first roller and the break plate of the hemming apparatus are manipulated to engage the opposite sides of the first metal panel by ensuring that the break plate is in the engaged position, positioning the first roller such that a base of the first canted surface is proximate to a base of the flange portion such that the first roller forces the flange portion to a bent position, and engaging the cam structure to move the break plate from the open position to the engaged position such that the break plate and the first roller clamp the flange portion to create the bend line at the base of the flange portion. 
     
     
         6 . The method of  claim 1  wherein the hemming apparatus comprises a cam structure to selectively move the break plate between an open position and an engaged position, and the first roller and the break plate of the hemming apparatus are manipulated to engage the opposite sides of the first metal panel by ensuring that the break plate is in the engaged position, positioning the first roller such that a base of the first canted surface is proximate to a base of the flange portion such that the first roller forces the flange portion to a bent position, and engaging the cam structure to move the break plate from the open position to the engaged position such that the break plate and the first roller clamp the flange portion to create the bend line at the base of the flange portion. 
     
     
         7 . The method of  claim 6  wherein the second roller includes a cylindrical outer surface that engages and forces the flange portion downwardly during one of the at least one successive passes along the length of the mated edges. 
     
     
         8 . The method of  claim 7  wherein the second roller includes a head portion having a canted surface that engages and forces the flange portion downwardly during one of the at least one successive passes along the length of the mated edges. 
     
     
         9 . The method of  claim 8  which comprises manipulating the hemming apparatus in a manner that the canted surface of the second roller moves from a first angular position with respect to the mated edges of the metal panels to a second angular position with respect to the mated edges of the metal panels, and wherein, while the second roller is in the second angular position, the second roller engages and forces the flange portion downwardly and against the second metal panel during one of the at least one successive passes along the length of the mated edges to form an edge-hemmed connection between the panels. 
     
     
         10 . A roller-type hemming apparatus for attaching panel edges in face to face assembly by folding a flange portion adjacent an edge of one panel over a mated edge of another panel to form a hemmed panel assembly, the apparatus comprising:
 a roller assembly having at least one roller capable of completing a finished edge hem along the length of the mated edges of the panels wherein the flange portion of the first panel is folded over in a gradual bend from one end to another end of the mated edges to effectively engage the flange with an outer side of the mated edge portion of the second panel and thereby maintain the panels in an assembly, a first roller including a cylindrical body, an annular rib, and a groove between the body and the rib, the rib having a diameter greater than the diameter of the body and the groove having a canted surface that conjoins with the rib, the outer surface of the body being adapted to engage and force the flange portion vertically downwardly towards the panel assembly when the first roller is in a first position, and the canted surface being adapted to both pull the flange portion towards the mated edges of the panels when the first roller is in a second position, and force the flange portion of the first panel against the mated edge portion of the second panel when the first roller is rotated in a rigid body movement in a third position.   
     
     
         11 . The roller-type hemming apparatus of  claim 10  which comprises:
 a support housing having an upper end adapted to connect to a manipulator, a lower end, an interior passage opening on the lower end, and a piston including a slide shaft and a piston head, the slide shaft disposed for movement within the interior passage, and the piston head disposed outside of the interior passage for movement away from and towards the support housing, the slide shaft and interior passage being disposed on a common geometrical axis;   a hemming carriage having opposite end sections and a break plate secured to one of the end sections for rotation relative thereto; and   the roller assembly further including a roller shaft having opposite ends and a second roller, the roller shaft secured within the piston head for axial up and downward movement therewith, and the first and second rollers mounted to opposite respective ends of the roller shaft.   
     
     
         12 . The roller-type hemming apparatus of  claim 11  which comprises:
 a cam structure for connecting the hemming carriage to the support housing and atop the piston head in a manner wherein outward extending axial movement of the piston head operates to drive the hemming carriage laterally of the slide shaft and into a first position, and rearward retracting axial movement of the piston head operates to drive the hemming carriage laterally of the slide shaft into a second position.   
     
     
         13 . The roller-type hemming apparatus of  claim 12  wherein the cam structure comprises at least one cam plate and associated cam finger secured to the support housing and forming in the hemming carriage a complementary cam slot for receiving the cam finger, the cam finger and cam slot being at an acute angle to the geometrical axis, wherein the length of the cam finger and cam slot and the degree of the acute angle thereof determines the amount of lateral movement of the hemming carriage relative to the support housing. 
     
     
         14 . The roller-type hemming apparatus of  claim 13  which comprises:
 two cam plates, each cam plate being disposed on a respective opposite side of the support housing to each other, and two cam slots, each of the cam slots being associated with a respective one of the cam plates.   
     
     
         15 . A hemming head configured for attachment to a robot for performing a hemming operation, the hemming head comprising:
 a support housing adapted for securement to the robot arm on a first end, and including a first roller rotatably secured to the support housing, the first roller including a cylindrical body, a head having a diameter greater than the body, and a groove between the body and head, the groove having a diameter less than the body and having a canted surface that conjoins with the head.   
     
     
         16 . The hemming head of  claim 15  wherein the cylindrical body is adapted to engage and force a workpiece edge downwardly to a first position and the canted surface is adapted to engage and force the workpiece from the first position to a second position. 
     
     
         17 . The hemming head of  claim 15  comprising a second roller rotatably secured to the support housing, and a hemming carriage having opposite end sections and a break plate secured to one of the end sections for rotation relative thereto. 
     
     
         18 . The hemming head of  claim 17  comprising a piston including a slide shaft and a piston head, the slide shaft disposed for movement within an interior passage of the support housing, and the piston head disposed outside of the interior passage for axial movement relative to the support housing, the slide shaft and interior passage being disposed on a common geometrical axis, and the first roller being rotatably secured to the piston head. 
     
     
         19 . The hemming head of  claim 18  which comprises:
 a cam structure for connecting the hemming carriage to the support housing and atop the piston head in a manner wherein outward extending axial movement of the piston head operates to drive the hemming carriage laterally of the slide shaft and into a first position, and rearward retracting axial movement of the piston head operates to drive the hemming carriage laterally of the slide shaft into a second position.   
     
     
         20 . The hemming head of  claim 19  wherein the cam structure comprises at least one cam plate and associated cam finger secured to the support housing and forming in the hemming carriage a complementary cam slot for receiving the cam finger, the cam finger and cam slot being at an acute angle to the geometrical axis.