US 4,730,823 A · Adaptive document feed pick mechanism

Abstract

Sheet feeder having adaptive mechanism for assuring dependable automatic operation when the stack of sheets to be fed consists of sheets having varying thicknesses and weights. In a sheet feeder having pickers to move a document from the top of a stack of sheets supported by a moveable table to a feed-in position, the latter possibly including a vacuum belt for moving the document, sensors supply signals to indicate a sheet has been picked. After moving the pickers and table to initial positions, the controller moves the picker to a predetermined reference position. If a sheet is picked above or below the predetermined initial position, the position of the table is adjusted accordingly. In a second embodiment in a recirculating automatic sheet feeder, the table is initially positioned then after feeding the sheets from the stack once, it is initialized at a second predetermined position depending on the number of documents in the stack and on the position of the table prior to picking the documents a second time.

Claims10

Dependent claims

A method of operating a sheet feeder for picking sheets one at a time from the top of a stack of sheets supported by a moveable table, and having pickers for attaching to and removing the top sheet from the stack of sheets, including stepping means for moving the pickers up or down incremental distance steps and sensor means for supplying a signal when a sheet is attached to said pickers, comprising the steps of:

placing the table at a first reference position;
positioning the pickers at a second reference position;
stepping the pickers one step at a time toward a third reference position;
moving the pickers upward with an attached sheet to a removal position in response to the sensor signal indicating a sheet is attached to the pickers;
continuing to step the pickers one step at a time past the third reference position if no sensor signal is supplied;
and
altering the position of the table if said signal is supplied before the pickers reach the third reference position.

4 more elements

The combination comprising:

means for adjusting the height of a stack of sheets to be picked one at a time from the top of the stack for feeding into a utility device;
picker means for attaching a top sheet from said stack, said picker means including sensor means for supplying an attach signal when the top sheet is attached to the picker means;
control means adapted to receive signals from said sensor means and to supply control signals for controlling sheet feeding operations;
means responsive to a control signal from said control means for moving said picker means to a reference position with respect to said stack of sheets;
means responsive to said attach signal for causing said pickers to remove said top sheet from said stack;
and
means for activating said adjusting means to change the position of the table if said attach signal occurs before said pickers are moved to said reference position.

4 more elements

Dependencies are inferred from the claim text.

Adaptive document feed pick mechanism

Life of this patent

Adaptive document feed pick mechanism

Life of this patent

Abstract

Claims10