Sheet retaining apparatus

Claim 2

Automatically repositionable apparatus for retaining a stack of cut sheets in alignment as sheets are separated and forwarded therefrom including a vertically aligned support body, a pivot pin mounted in said body, an extended tab having one end rotatably mounted upon said pivot pin and being arranged to swing downwardly from a first horizontally extended position to a second position substantially parallel to said body, mechanical biasing means including a torsion spring wound about said pivot pin in working condition with the end coils of said spring acting upon the body and the tab respectively to urge said tab into said first position, a stop affixed to said body and being engageable by said tab when in said first position wherein said tab is prevented from swinging beyond said first position and means to move said body along a path of travel substantially parallel to the front margin of the stack.

Claim 3

Apparatus to retain a stack of cut sheets of support material in sheet-feeding alignment as individual sheets are separated and forwarded therefrom, said apparatus including a lifting arm pivotally mounted at one end below the stack and arranged to move in a plane substantially parallel to the front margin of the stack, a body member mounted to rotate freely in the free end of said lifting arm wherein said body member remains in constant alignment in relation with the front margin of the stack as the lifting arm moves through said plane, a stack-engaging member mounted upon said body in a position to engage the uppermost sheet in said stack to support said stack in alignment as sheets are separated and forwarded therefrom.

Claim 4

Apparatus to retain a stack of cut sheets of support material in sheet-feeding alignment as individual sheets are separated and forwarded therefrom, said apparatus including a lifting arm pivotally mounted at one end below the stack and arranged to move in a plane substantially parallel to the front margin of the stack, a body member mounted to rotate freely in the free end of said lifting arm wherein said body member remains in constant alignment in relation with the front margin of the stack as the lifting arm moves through said plane, a stack-engaging member mounted upon said body in a position to engage the uppermost sheet in said stack to support said stack in alignment as sheets are separated and forwarded therefrom.

Claim 5

The apparatus of claim 2 wherein said stack-engaging member comprises an extended tab being movably mounted on said body member and being arranged to swing downwardly from a first stack-engaging position perpendicular to said plane and a second nonengaging position substantially parallel to said plane.

Claim 6

The apparatus of claim 3 further including mechanical biasing means to urge said extended tab toward said first position.

Claim 7

The apparatus of claim 4 having further means to momentarily elevate the free end of said lifting arm above the level of said stack.

Claim 8

Apparatus to support a stack of cut sheets in sheet-feeding alignment as individual sheets are separated and forwarded from the top thereof, said apparatus including a horizontal support tray having vertically extended side and rear margin guides being arranged to support a stack of cut sheets therebetween, said support tray being movable between an operative position and a loading position, a plurality of lifting arms journaled for rotation at one end in said support tray below the level of the stack and being arranged to move in a plane substantially parallel to the front margin of the stack, a vertically aligned body member mounted to rotate freely in the free ends of each of said lifting arms wherein said body member remains in constant alignment in relation to the front margin of the stack as the lifting arms move in said plane, a stack-retaining tab movably supported in each of said body members and being capable of being urged downwardly from a normally maintained first stack-engaging position wherein said tab is extended substantially perpendicular to said plane towards a second position wherein said tab is substantially parallel to said plane, actuating means to operatively engage said lifting arms and guide said lifting arms through a prescribed path of travel wherein the free ends of said arms are elevated momentarily above the level of the stack.

Claim 9

Apparatus to support a stack of cut sheets in sheet-feeding alignment as individual sheets are separated and forwarded from the top thereof, said apparatus including a horizontal support tray having vertically extended side and rear margin guides being arranged to support a stack of cut sheets therebetween, said support tray being movable between an operative position and a loading position, a plurality of lifting arms journaled for rotation at one end in said support tray below the level of the stack and being arranged to move in a plane substantially parallel to the front margin of the stack, a vertically aligned body member mounted to rotate freely in the free ends of each of said lifting arms wherein said body member remains in constant alignment in relation to the front margin of the stack as the lifting arms move in said plane, a stack-retaining tab movably supported in each of said body members and being capable of being urged downwardly from a normally maintained first stack-engaging position wherein said tab is extended substantially perpendicular to said plane towards a second position wherein said tab is substantially parallel to said plane, actuating means to operatively engage said lifting arms and guide said lifting arms through a prescribed path of travel wherein the free ends of said arms are elevated momentarily above the level of the stack.

Claim 10

The apparatus of claim 6 further including means to activate said actuating means as said tray is moved from a loading position to an operative position wherein the lifting arms position said retaining tabs in engagement with the uppermost sheet in the stack.

Claim 11

The apparatus of claim 7 further including automatic control means to operatively engage and activate said actuating means to reposition said retaining tabs when the tray is in the operative position.

Claim 12

In a supply tray for supporting a stack of cut sheets of material as the sheets are fed one by one from said stack, apparatus for supporting the stack in alignment including at least one lifting arm pivotally supported at one end in the tray below the level of the stack and being arranged to move in a plane substantially parallel to the front margin of the stack, said lifting arm supporting in the free end thereof a stack-retaining member for engaging the uppermost sheet in the stack and supporting the stack against movement, a leveR arm rotatably supported in a substantially horizontal position below the level of the stack and having means at one end thereof to operatively engage said lifting arm, drive means to operatively engage the opposite end of said lever arm and move said lever arm through a prescribed path of travel wherein the free end of the lifting arm is momentarily elevated above the level of said stack to place the retaining member in engagement with the uppermost sheet therein.

Claim 13

In a supply tray for supporting a stack of cut sheets of material as the sheets are fed one by one from said stack, apparatus for supporting the stack in alignment including at least one lifting arm pivotally supported at one end in the tray below the level of the stack and being arranged to move in a plane substantially parallel to the front margin of the stack, said lifting arm supporting in the free end thereof a stack-retaining member for engaging the uppermost sheet in the stack and supporting the stack against movement, a leveR arm rotatably supported in a substantially horizontal position below the level of the stack and having means at one end thereof to operatively engage said lifting arm, drive means to operatively engage the opposite end of said lever arm and move said lever arm through a prescribed path of travel wherein the free end of the lifting arm is momentarily elevated above the level of said stack to place the retaining member in engagement with the uppermost sheet therein.

Claim 14

The apparatus of claim 9 further including control means to activate said drive means when new sheets are added to the stack wherein the retaining members are elevated to engage the newly added uppermost sheet in the stack.