bolts not shown can be adjustably extended through slot 80a and connected to forming device 23 forming device 23 moves up and down with movable plate 61 but can be adjusted relative to block 81 and sealing wire 35 when shaft 52 fig2 oscillates wire 35 rocks back and forth over the surface of tube 24 in the same manner as rocking chair runners rock over a floor the remainder of the apparatus disclosed in fig2 provides an oscillating motion to shaft 52 and lifts wire 35 away from tube 24 when tube 24 is not moving the oscillation of shaft 52 fig2 is actuated by a cam 83 having a heart shaped groove 84 and a cam follower 85 positioned in groove 84 cam 83 is mounted off center on a rotatable shaft 89 which is rotatably driven by a pulley 90 through a worm gear 91 a drive belt 95 supplies power to drive pulley 90 cam follower 85 is mounted on a pin 96 which is connected to a horizontal member 97 horizontal member 97 is connected to a pair of bushings 102 only one being shown bushings 102 are slidably mounted on a pair of vertical rods 103 connected between a pair of rod support blocks 106 107 blocks 106 107 are secured to a support plate 108 by a plurality of bolts 109 worm gear 91 is mounted on a plate 110 which is secured to plate 108 by a plurality of bolts 109a when cam 83 rotates cam follower 85 member 97 and bushing 102 move up and down as cam follower 85 moves in groove 84 a toothed.