Anti-rotation device and method of use

A system for singulating a stack of articles comprising:

• a base;
• a conveyor belt connected to the base, the conveyor belt configured to move a stack of articles forward;
• a drive belt disposed proximate to the conveyor belt such that, as the stack of articles moves forward, the stack of articles contacts the drive belt, the drive belt configured to laterally accelerate an article in the stack of articles;
• and
• an anti-rotation device disposed proximate the drive belt such that a portion of the anti-rotation device is capable of contacting the drive belt, and configured to provide a frictional force to a back face of the article, to thereby resist upward motion of the back face during lateral acceleration of the article, the anti-rotation device comprising:
• a torsion element connected directly or indirectly to the base,
• a rotatable member coupled to the torsion element and rotatable between at least a first position and a second position about an axis extending through the center of the torsion element,
• a revolving member coupled to the rotatable member and configured to revolve about an axis perpendicular to the base;
• wherein, when the rotatable member is in a first position, an outer surface of the revolving member is in contact with the drive belt, and
• wherein, when the rotatable member is in the second position, the torsion element applies a torque to the rotatable member and the revolving member, the outer surface of the revolving member is in contact with the back face of the article, and the front face of the article is in contact with the drive belt.

A system for singulating a stack of articles comprising:

• means for moving a stack of articles forward;
• means for separating and laterally accelerating a forward-most article from the stack of articles;
• and
• means for applying friction to a back face of the forward-most article to resist upward motion of the back face during lateral acceleration of the forward-most article.

A method of singulating a stack of articles while reducing damage to each article, the method comprising:

• moving a stack of articles forward;
• separating and laterally accelerating a forward-most article from the stack of articles;
• and
• applying a force to a back face of the forward-most article to resist upward motion of the back face during lateral acceleration of the forward-most article, wherein the force is applied to the back face by a revolving member indirectly coupled to a torsion element.