Sheet feed device for printing machines and the like

Claim 2

A sheet feed device, for printing and the like sheetutilizing machines having a frame, said device comprising, in combination, a sheet feed tray mounted on said frame; a pair of sheet hold-down members pivotally mounted on said tray and having respective pawls for holding down front corners of sheets stacked on said tray; a lifting member mounted on said frame in a position to engage said hold-down members; externally accessible operating means operable to move said lifting member from an inoperative position, out of engagement with said hold-down members, into engagement with said hold-down members and to an operative position lifting said hold-down members to an upper inoperative position, for stacking a fresh supply of sheets on said tray; holding means on said frame operable to retain said lifting member in its operative position; a sheet feed roller manually movable, independently of said operating means, between an operative position, engaging a sheet stack on said tray, and a retracted position permitting reloading of said tray; and first release means engageable and operable by said roller, upon movement thereof toward its operative position, to release said holding means for return of said lifting member to its inoperative position and lowering of said hold-down members into engagement with sheets stacked on said tray.

Claim 3

A sheet feed device, as claimed in claim 1, in which said sheet feed tray has side flanges; said hold-down members being pivotally supported by said side flanges.

Claim 4

A sheet feed device, as claimed in claim 1, in which said hold-down members have depending feet each adjacent a respective pawl; a shaft rotatably mounted on said frame; said lifting member comprising a U-shape member including a pair of legs secured to said shaft for rotation therewith and interconnected by a bight disposed beneath said feet and engageable with said feet upon movement of said lifting member toward its operative position.

Claim 5

A sheet feed device, as claimed in claim 3, in which said externally accessible operating means comprises an arm secured to an outwardly projecting end of said shaft.

Claim 6

A sheet feed device, as claimed in claim 4, in which said sheet feed roller is rotatably supported by a pair of roller support arms pivotal on a second shaft supported in said frame; said lifting member including an engaging arm secured to rotate with said first-mentioned shaft and having a bent free end; said holding means comprising a holding lever pivotal on said second shaft and having an arm formed with a notch at its free end engageable with said bent end of said engaging arm upon movement of said lifting member to its operative position to retain said lifting member in its operative position; and means on one of said support arms engageable with a second arm of said holding lever upon movement of said sheet feed roller toward its operative position, to rock said holding lever to release said bent end of said engaging arm for return of said lifting member to its inoperative position.

Claim 7

A sheet feed device, as claimed in claim 5, in which said means and said one support arm engageable with said holding lever comprises a pin extending through an arcuate slot in said frame and which is centered on the axis of said second shaft; said holding lever having a second arm engageable by said pin.

Claim 8

A sheet feed device, for printing and the like sheet-utilizing machines having a frame, said device comprising, in combination, a sheet feed tray mounted on said frame; a pair of sheet hold-down members pivotally mounted on said tray and having respective pawls for holding down front corners of sheets stacked on said tray; a lifting member mounted on said frame in a position to engage said hold-down members; externally accessible operating means operable to move said lifting member from an inoperative position, out of engagement with said hold-down members, into engagement with said hold-down members and to an operative position lifting said hold-down members to an upper inoperative position, for stacking a fresh supply of sheets on said tray; holding means on said frame operable to retain said lifting member in its operative position; a sheet feed roller movable between an operative position, engaging a sheet stack on said tray, and a retracted position permitting reloading of said tray; and first release means operable responsive to movement of said roller toward its operative position, to release said holding means for return of said lifting member to its inoperative position and lowering of said hold-down members into engagement with sheets stacked on said tray; said sheet feed tray being mounted on said frame for movement between an inoperative retracted position and an operative sheet feeding position by external manipulation; and second release means operable, responsive to movement of said tray to its inoperative retracted position, to release said holding means for return of said lifting member to its inoperative position.

Claim 9

A sheet feed device, for printing and the like sheet-utilizing machines having a frame, said device comprising, in combination, a sheet feed tray mounted on said frame; a pair of sheet hold-down members pivotally mounted on said tray and having respective pawls for holding down front corners of sheets stacked on said tray; a lifting member mounted on said frame in a position to engage said hold-down members; externally accessible operating means operable to move said lifting member from an inoperative position, out of engagement with said hold-down members, into engagement with said hold-down members and to an operative position lifting said hold-down members to an upper inoperative position, for stacking a fresh supply of sheets on said tray; holding means on said frame operable to retain said lifting member in its operative position; a sheet feed roller movable between an operative position, engaging a sheet stack on said tray, and a retracted position permitting reloading of said tray; and first release means operable responsive to movement of said roller toward its operative position, to release said holding means for return of said lifting member to its inoperative position and lowering of said hold-down members into engagement with sheets stacked on said tray; said sheet feed tray being mounted on said frame for movement between an inoperative retracted position and an operative sheet feeding position by external manipulation; and second release means operable, responsive to movement of said tray to its inoperative retracted position, to release said holding means for return of said lifting member to its inoperative position.

Claim 10

A sheet feed device, as claimed in claim 7, in which said sheet hold-down members are formed with depending feet each adjacent a respective pawl; a first shaft rotatably mounted on said frame; said lifting member comprising a U-shape member having a pair of legs secured to said first shaft to rotate therewith and interconnected by a bight positioned beneath said feet and engageable therewith upon movement of said lifting member to its operative position; said externally accessible operating means comprising an operating arm secured to a projecting end of said first shaft exteriorly of said frame; said sheet feed roller being rotatably supported by a pair of roller support arms pivotal on a second shaft mounted in said frame; said lifting member further including an engaging arm secured at one end to said first shaft and having a bent free end; said holding means comprising a holding lever pivotal on said second shaft and having a first arm formed with a notch in its free end engageable with the bent end of said engaging arm upon movement of said lifting member to its operative position to lock said lifting member in its operative position; said first release means comprising a pin on one of said roller support arms extending through an arcuate slot in said frame and which is concentric with the axis of said second shaft; and a second arm on said holding lever positioned in the path of movement of said pin and engageable thereby, upon movement of said roller toward its operative position, to rock said holding lever to disengage said notch from the bent end of said engaging arm to release said lifting member to return to its inoperative position.

Claim 11

A sheet feed device, as claimed in claim 8, including a third shaft pivotally mounting said tray for movement between its inoperative retracted position and its operative sheet feeding position; a rod extending transversely of said tray and extending through a second arcuate slot in said frame and concentric with the axis of said third shaft; said second release means comprising a three-arm lever pivotal on said third shaft and having first and second arms extending across said second arcuate slot and spaced apart an angular distance less than the range of angular movement of said rod for engagement by said rod as said rod reaches its limit of movement in either direction during movement of said tray between its inoperative retracted position and its operative sheet feeding position; the third arm of said three-arm lever, upon movement of said tray to its inoperative retracted position being swung, by the oscillation imparted to said three-arm lever by said rod, to engage said third arm with said second arm of said holding lever to release said notch from said bent end of said engaging arm.

Claim 12

A sheet feed device, as claimed in claim 9, including means restraining inadvertent pivotal movement of said three-arm lever.