Sheet feeder

A feed wheel assembly for conveying an end sheet from a stack of sheets, comprising:

• a rotatable engagement wheel positionable to contact the end sheet of the stack and operable to separate and convey the end sheet from the stack;
• a generally horizontally extending first shaft on which said wheel is mounted, said first shaft being angularly movable in a generally vertical direction;
• a generally horizontally extending second shaft positioned spaced apart from said first shaft, said second shaft being mountable in a substantially fixed planar orientation;
• a pair of laterally spaced-apart first and second arms extending between said first and second shafts, each of said first and second arms having a first portion retaining said first shaft and a second portion longitudinally spaced from said first portion and pivotally connected to said second shaft, said first and second arms being pivotally movable about said second shaft within at least a limited range to permit uninhibited angular movement of said first shaft in a generally vertical direction during operation;
• a connector positioned intermediate of said wheel and said second shaft and extending between said first and second arms, said connector being pivotally attached to each of said first and second arms;
• and
• a link extending between said second shaft and said connector, said link being attached to said second shaft and said connector to rotate said second shaft in response to vertical movement of said first shaft and being axially rotatable relative to at least one of said second shaft or said connector to permit angular movement of said first shaft.

A sheet feeder, comprising:

• a receiving tray for holding a stack of sheets;
• an incrementally driven engagement wheel positioned above said receiving tray for contact with the upper sheet of the stack and operable to separate ad convey the upper sheet from the stack by rotation of said wheel;
• a generally horizontally extending first shaft on which said engagement wheel is mounted;
• a generally horizontally extending second shaft positioned spaced apart from said first shaft, said second shaft being mountable in a substantially fixed position;
• a pair of laterally spaced-apart first and second arms extending between said first and second shafts, each of said first and second arms having a first portion retaining said first shaft and a second portion longitudinally spaced from said first portion and pivotally connected to said second shaft, said first and second arms being pivotally movable about said second shaft within at least a limited range to permit free angular movement of said first shaft in a generally vertical direction during operation;
• feed means for receiving the upper sheet conveyed by said engagement wheel and feeding the upper sheet along a feed path to the apparatus to which the sheet feeder is connected;
• a connector positioned intermediate of said engagement wheel and said second shaft and extending between said first and second arms, said connector being pivotally attached to each of said first and second arms;
• and
• a link extending between said second shaft and said connector, said link being attached to said second shaft and said connector to rotate said second shaft in response to vertical movement of said first shaft and being axially rotatable relative to at least one of said second shaft or said connector to permit angular movement of said first shaft.

A sheet feeder, comprising:

• a receiving tray for holding a stack of sheets;
• an incrementally driven engagement wheel positioned above said receiving tray for contact with the upper sheet of the stack and operable to separate and convey the upper sheet from the stack by rotation of said wheel;
• a generally horizontal extending first shaft on which said engagement wheel is mounted;
• a generally horizontally extending second shaft positioned spaced apart from said first shaft, said second shaft being mountable in a substantially fixed position;
• a pair of laterally spaced-apart first and second arms extending between said first and second shafts, each of said first and second arms having a first portion retaining said first shaft and a second portion longitudinally spaced from said first portion and pivotally connected to said second shaft, said first and second arms being pivotally movable about said second shaft within at least a limited range to permit free angular movement of said first shaft in a generally vertical direction during operation;
• feed means for receiving the upper sheet conveyed by said engagement wheel and feeding the upper sheet along a feed path to the apparatus to which the sheet feeder is connected, said feed means includes at least one pair of opposed upper and lower feed rollers biased toward each other and between which the upper sheet of the stack is received from said engagement wheel, said upper feed roller being mounted on an upper shaft and said lower feed roller being mounted on a lower shaft, and the sheet feeder further including means for detecting more than one sheet being conveyed by said engagement wheel between said upper and lower feed rollers, said detecting means including an upper detector roller positioned generally coaxial with said upper feed roller and having an enlarged axial opening for uninhibited passage of said upper shaft therethrough, a lower detector roller mounted on said lower shaft, a link rotatably supporting said upper detector roller in a position a preselected distance above said lower detector roller and connecting said upper detector roller to a detector shaft for translating vertical movement of said upper detector roller responsive to passage of more than one sheet between said upper and lower detector rollers into rotational movement of said detector shaft, an enlongated arm fixedly attached by one end portion to said detector shaft and having a vane as its opposite end portion for interrupting a beam of light projecting between a light source and a photodetector, passage of more than one sheet between said upper and lower detector rollers producing rotation of said detector shaft to move said vane into or out of said beam of light and thereby generating an indicator signal, and said detector means further including first adjustment means for adjusting said position of said upper detector roller above said lower detector roller to adjust said distance therebetween according to the thickness of the sheets being feed, said first adjustment means including a hand operated knob rotatable between at least two rotational positions, each corresponding to a thickness of the sheets being fed, and actuation means responsive to rotation of said knob between said at least two rotational positions to adjustably fix said distance of said upper detector roller above said lower detector roller to cause said indicator signal to be generated only when more than one sheet of the thickness sheet being fed passes between said upper and lower detector rollers, said knob having an interiorly threaded portion and an exteriorly threaded portion, said exteriorly threaded portion being threadably received by a correspondingly threaded fixed member, and said actuation means includes a threaded shaft threadably received by said interiorly threaded portion of said knob and having threads corresponding thereto, said interiorly and exteriorly threaded portions of said knob having the same hand threads with different lead angles to produce differential movement between said shaft and said knob and to move said shaft axially upon rotation of said knob, said shaft engaging said elongated arm for movement thereof, whereby movement of said arm is transmitted through said link to adjust the position of said upper detector roller above said lower detector roller.