Abstract: An apparatus for sensing the height of a stack of cards is disclosed. The apparatus includes a bar having a projecting portion that is adopted to engage the upper surface of the uppermost card in the stack; a spring that biases the bar in a position so that it does not engage the stack; and a solenoid which displaces the bar downward in response to an actuating signal. Both means for urging the projecting portion of the bar into contact with the upper surface of the uppermost card in the stack as the bar is urged downward by the solenoid and means responsive to the position of the bar to provide a signal that indicates the height of the stack, are included.

Abstract: An apparatus for straightening a stack of cards is disclosed. The apparatus includes a frame, an arm pivotally secured to the frame at one end thereof, a spring biasing the arm away from the stack of cards, a leaf spring secured at one end thereof to the arm near the pivoted end resiliently biased toward the stack of cards, a backstop secured to the frame, and a solenoid that can be actuated to project the arm toward the stack of cards so that the leaf spring presses against the stack of cards and also to urge the upper most cards in the stack against the backstop.

Abstract: An apparatus for filming a plurality of index or library cards is disclosed which feeds, spaces and photographs the individual cards automatically. The apparatus is provided with a means for sensing the height of cards in a stack, adjusting the height of the stack so that a feeding mechanism may properly engage the cards for delivering them to a belt. The cards are photographed on the belt and are held stationary thereon by means of an electric charge on the individual cards so that they adhere to the surface of the belt. Subsequent to being photographed, the cards are restacked in the same order as they were stacked prior to being photographed.

Abstract: An apparatus for filming a plurality of index or library cards is disclosed which feeds, spaces and photographs the individual cards automatically. The apparatus is provided with a means for sensing the height of cards in a stack, adjusting the height of the stack so that a feeding mechanism may properly engage the cards for delivering them to a belt. The cards are photographed on the belt and are held stationary thereon by means of an electric charge on the individual cards so that they adhere to the surface of the belt. Subsequent to being photographed, the cards are restacked in the same order as they were stacked prior to being photographed.