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US 4,469,320 AGranted
Dual mode stack sensor
AssigneeXerox Corporation
InventorStephen J. Wenthe, Jr.
Life of this patent
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AssigneeXerox Corporation
InventorStephen J. Wenthe, Jr.
Estimating the term…
In a sheet feeder wherein sheets are fed from the bottom of a stack of the sheets in a stack support there is disclosed an automatic integral plural mode sheet stack sensor which, in a first mode, controls a variable pneumatic feeding means in response to sensing the height of the stack of sheets, and which, in a second mode, provides a signal indicative of the feeding from the stack support of all of the sheets in the stack. As further disclosed, a finger member is resettable on top of the stack of sheets, and a first switch is actuable by a first position of the finger member to increase the output of an air knife for assisting the bottom sheet feeder when the finger member is reset on top of the stack of sheets and the height of the stack of sheets exceeds a preset level, and a second switch is actuable for the second mode by the dropping of the finger member into a second position in response to all of the sheets being fed out from under the finger, and a fed sheet counter is connected to control the same variable pneumatic control so as to override the first mode control from the sheet stack sensor if a number of sheets is counted exceeding a preset count before the second mode signal.
In a sheet feeder with a sheet stack support wherein sheets are fed from a stack of the sheets in said stack support using variable pneumatic feeding means, the improvement comprising an automatic integral plural mode sheet stack sensor which, in a first mode, controls said variable pneumatic feeding means in response to sensing the height of the stack of sheets in said stack support, and which, in a second mode, provides a signal indicative of the feeding from said stack support of all of the sheets in said stack, wherein said integral plural mode sheet stack sensor includes:
In a method of feeding sheets from the bottom of a sheet stack using variable pneumatic sheet feeding means, the improvement comprising sensing, with an automatic integral plural mode sheet stack sensor, the height of the stack of sheets in said stack support in a first mode to control the variable pneumatic sheet feeding means, and sensing in a second mode, with said same integral sheet stack sensor, the feeding from said stack support of all of the sheets in said stack and providing a signal indicative thereof, further including the steps of setting a finger member on top of the stack of sheets in said first mode and activating first switch means in response to a first position of said finger member when said finger member is set on top of the stack of sheets and the height of the stack of sheets in a stack support exceeds a preset level, then allowing said finger member to drop by gravity as sheets are fed out from under it, and actuating second switch means for said second mode by the dropping of said finger member into a second position in response to all of the sheets being fed out from under said finger.
Dependencies are inferred from the claim text.