Elbow formation apparatus

Abstract

An apparatus for forming and rotating interconnected sections of a cylindrical sheet metal workpiece to provide an elbow. The apparatus includes a frame, a head rotatably arranged within the frame and a tool ring mounted to the frame, the head and tool ring being co-operable for sectioning and joining segments of the workpiece. The apparatus also includes a drive drum mounted within the frame for gripping and rotating the segments, and a control module for selectively activating the head, the ring, and the drive drum to form an elbow.

1 . An apparatus for forming an elbow from a sheet metal tube with an outer diameter within a predetermined range of diameters, said apparatus comprising:
 a frame defining a vertical axis and a tube axis offset from the vertical axis by a tube angle;   a top plate, mounted to the top of said frame, with a through-hole defining a cut axis offset from the tube axis by a cut angle;   a tool ring rotatably mounted to said top plate substantially coaxial with and surrounding the through-hole;   a tool shoe slidably mounted to said tool ring for radial motion toward and away from the cut axis across the through-hole, according to the diameter of said sheet metal tube, rotation of said tool ring within said top plate causing the radial motion of said tool shoe;   a baseplate supported within said frame below said top plate and substantially perpendicular to the tube axis;   a locking drum assembly supported within said frame between said top plate and said baseplate and substantially coaxial with the tube axis, said locking drum assembly including clamp heads for gripping said sheet metal tube, the clamp heads being radially movable within said locking drum assembly toward and away from the tube axis according to the diameter of said sheet metal tube, and the locking drum assembly being rotatably movable within said frame by means of a locking drum motor;   an arbor column mounted to said baseplate substantially parallel with the tube axis;   an arbor head mounted to said arbor column, said arbor head including a pinhead rotatable about an arbor axis substantially parallel with the cut axis;   a slide block slidably mounted on said arbor head, rotation of the pinhead causing radial motion of said slide block toward and away from the arbor axis; and   a jointless drivetrain extending from the pinhead of said arbor head through said arbor column, substantially parallel with the cut axis and to the arbor axis, and operatively connecting the pinhead to a motor.   
   
   
       2 . The apparatus as claimed in  claim 1 , wherein the tube angle is about thirty (30) degrees. 
   
   
       3 . The apparatus as claimed in  claim 1 , wherein the cut angle is about fifteen (15) degrees. 
   
   
       4 . The apparatus as claimed in  claim 1 , wherein the cut angle is about twenty two and one half (22.5) degrees. 
   
   
       5 . The apparatus as claimed in  claim 1 , wherein said tool shoe is selected from one of a plurality of tool shoes interchangeably connectable to said tool ring, according to the diameter of said sheet metal tube. 
   
   
       6 . The apparatus as claimed in  claim 1 , wherein said locking drum assembly includes an irising clamp having an outer ring and an inner ring, the clamp heads being slidably connected to the outer ring and slidably pivotally connected to the inner ring for radially oscillating motion as said locking drum assembly rotates within said frame continuously in a single direction about the tube axis. 
   
   
       7 . The apparatus as claimed in  claim 1 , wherein said jointless drivetrain includes a sequence of offset shafts extending substantially parallel with the cut axis operatively connected by offset gearsets, the lowest shaft of the sequence terminating in a beveled pinion gear having tooth flanks that are substantially parallel with the tube axis at a location where the beveled pinion gear meshes with a driving gear. 
   
   
       8 . The apparatus as claimed in  claim 1 , wherein said tool ring includes an outer ring clamped to said top plate, a slotted ring having a spiral slot and rotatably mounted within the outer ring, and a motor operatively connecting the slotted ring to the outer ring, and said tool shoe is radially slidably mounted to the outer ring of said tool ring and is slidably engaged with the spiral slot of the slotted ring, so that rotation of the slotted ring within the outer ring causes inward or outward radial motion of said tool shoe. 
   
   
       9 . The apparatus as claimed in  claim 8 , wherein said spiral slot provides for about one (1) inch radial motion of said tool shoe. 
   
   
       10 . The apparatus as claimed in  claim 8 , comprising first, second and third tool shoes respectively engaged with first, second, and third spiral slots equally circumferentially spaced around the slotted ring of said tool ring. 
   
   
       11 . The apparatus as claimed in  claim 8 , further comprising a control module operatively connected to selectively actuate the motor of said jointless drivetrain, the motor of said locking drum assembly, and the motor of said tool ring. 
   
   
       12 . The apparatus as claimed in  claim 11 , wherein at least one of the motors is a hydraulic motor. 
   
   
       13 . The apparatus as claimed in  claim 11 , wherein said control module is programmed to cut and bead three fifteen (15) degree joints at substantially equal spacings along said sheet metal tube, upon insertion of said tube through the through-hole of said top plate to contact said baseplate. 
   
   
       14 . The apparatus as claimed in  claim 13 , wherein said control module is actuated to execute its program by contact of said tube against said baseplate. 
   
   
       15 . The apparatus as claimed in  claim 13 , said arbor column further including a limit switch, wherein said control module is actuated to execute its program by actuation of the limit switch. 
   
   
       16 . The apparatus as claimed in  claim 1 , wherein said arbor column is movable relative to said baseplate along the tube axis, said jointless drivetrain being driven by a beveled pinion gear having tooth flanks that are substantially parallel with the tube axis at a location where the beveled pinion gear meshes with a driving gear. 
   
   
       17 . The apparatus as claimed in  claim 1 , wherein the tube angle is negligibly small such that the tube axis is parallel with the vertical axis.