Patent ID: 7594647

Claim:
A device to move media sheets within an image forming apparatus, the device comprising: an input area sized to hold a stack of the media sheets, the input area including a support floor; an arm having a moveable first end and a second end, the arm pivotally connected to the image forming apparatus adjacent to the second end with the second end spaced a fixed distance from the support floor and being spaced a greater distance from the support floor than the movable first end such that the arm forms acute angles with the support floor, the arm applying a downward force to the stack; a roller operatively connected to the movable first end of the arm and positioned to remain in contact with a top-most media sheet of the stack to individually move each of the media sheets from the input area; a mechanism including a first end connected to the arm and a second end connected to the image forming apparatus, the mechanism operable in; a first state corresponding to the first end of the arm being positioned above a predetermined height in the device such that the distance between the first and the second ends of the mechanism is less than a predetermined length and the mechanism provides substantially no upward forces on the arm; a second state corresponding to the first end of the arm being positioned at the predetermined height in the device such that the distance between the first and second ends of the mechanism being substantially equal to the predetermined length such that the mechanism engages the arm to exert a counterbalance force on the arm of a first force amount; and a third state corresponding to the first end of the arm being positioned below the predetermined height in the device and the and the distance between the first and the second ends of the mechanism being greater than the predetermined length such that the mechanism engages the arm to exert the counterbalance force on the arm of an amount greater than the first force amount, the arm and mechanism exerting an overall downward force to media sheets in the input area at a first overall force amount while the mechanism is in the first state, and at a second overall force amount that is less than the first overall force amount while the mechanism is in the second and third states, the overall downward force gradually decreasing as the first end of the arm decreases from the predetermined height, the predetermined height corresponding to a height of a stack of media sheets that is less than a maximum number of sheets maintained in the input area.