Patent ID: 6837156

Claim:
A twist tie feed device for twisting together the ends of a tie ribbon encircling an article which is positioned therein for tying comprising: a twist head assembly constructed to receive and grasp a first end of said tie ribbon and a second end of said encircling tie ribbon and rotate about itself to twist said tie ribbon about an article and form a tie extending away from said article, said twist head assembly including: a first gripper adjacent to a position at which an article is to be placed for tying, the first gripper being operatively coupled to a first pneumatic cylinder and including a movable covering being movable via said first pneumatic cylinder so as to provide a first open position providing an aperture through which a tie ribbon can pass therethrough and a first closed position wherein said aperture is closed, thereby clamping a first end of said tie ribbon, and a second gripper adjacent to the position at which an article is to be placed for tying, the second gripper being operatively coupled to a second pneumatic cylinder and including a movable covering being movable via said second pneumatic cylinder so as to provide a second open position providing an aperture through which said tie ribbon can pass therethrough and a second closed position wherein said aperture is closed, thereby clamping a second end of said tie ribbon so that said first end of said tie ribbon substantially overlaps said second end of said tie ribbon; a rotator coupled to said first gripper and second gripper for rotating said first gripper and second gripper in unison about a common axis so that when the first gripper and second gripper are in the first closed position and second closed position respectively, the clamped ends of the tie ribbon will be twisted relative to each other, said rotator being coupled to a positive driver; said positive driver positioned along a feed path of the tie ribbon for selectively feeding said tie ribbon in one of a first direction toward said twist head assembly and in a second direction away from said twist head assembly, said tie ribbon having a first side and a second side, said positive driver including: one or more drive rollers contacting said tie ribbon at said first side of said tie ribbon to apply a positive drive force to said first side of said tie ribbon as it passes through said positive driver and an idler contacting said tie ribbon at said second side to apply a pressure on said tie ribbon toward said one or more drive rollers wherein said idler is movable to adjust to the direction of ribbon feed.