Abstract:
Sheet receiving apparatus is disclosed for receiving paper sheets from a supply of printed sheets, aligning the sheets edgewise, dropping the sheets to a receiver tray through horizontally openable preliminary sheet supporting plates, the sets of sheets being either stacked in vertical alignment or horizontally offset relationship, and in one form means are provided for stapling the sets of sheets.

Description:
BACKGROUND OF THE INVENTION 
     In the prior art there are extant various modes and systems for facilitating the stacking of sheets on or in a receiving tray, including the following prior art. 
     Lawrence U.S. Pat. No. 5,649695, granted Jul. 7, 1997 discloses a continuous finishing apparatus for copiers and printers in which sheets exiting the host machine are supported at their trailing edge on a retractable shelf and on their leading ends on a mechanism which is laterally shiftable. The shelf is retracted and the laterally shiftable mechanism is opened to allow the sheets to fall upon a stacker, after a set of the sheets has been finished. 
     In the pending application of Coombs, Ser. No. 09/078,202, filed May 14, 1998, commonly owned herewith, sheet finishing apparatus is shown having vertically spaced pairs of trays which are laterally pivotable to allow the sheet to progressively move downwardly to a stacker during the finishing of sheets by stapling or binding. 
     In essence, the state of the prior art appears to be that it is well known to support sheets and accumulate sets of sheets for binding or stapling on devices which finish the sets of sheets and then move the sheets to a stacker or receiver, as more particularly shown in Hiroi, et al U.S. Pat. No. 5,385,340, granted Jan. 31, 1995, wherein the sheets are arranged in a stack supported partially on a stacker and partially on a ledge from which the finished sets of sheets are pushed so as to rest entirely on the stacker. 
     SUMMARY OF THE INVENTION 
     The present invention involves providing a sheet receiving apparatus which is applicable to various stackers of the type having a stacker tray progressively vertically downwardly movable as the sets are deposited on the stacker tray, as is customary in the art of stacking. 
     The receiving apparatus of the present invention is adapted to receive sheets progressively fed from the outlet from a copier or printer upon a pair of horizontally shiftable support plates on which the sheets may be jogged into side edge alignment, and, in one form of the invention, stapled, but in any event, being dropped onto the usual stacker tray, either in a uniform vertically disposed stack or in a stack in which the respective jobs have been offset. 
     In particular, an object of the invention is to provide a universal sheet receiving apparatus which may be applied to a variety of stacking bases and which functions to receive, align and deposit the sheets upon the sheet stacker, either stapled or not stapled. 
    
    
     Other objects of the invention will be apparent from the following description and the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation of stacking apparatus adapted for use in conjunction with a copying or printing machine and incorporating the sheet receiver of the invention; 
     FIG. 2 is a top plan view thereof with covers removed; 
     FIG. 2A is a section embraced by line  2 — 2  of FIG. 2; 
     FIG. 3 is an enlarged top plan of one side of the apparatus with the sheet supporting plate fully extended; 
     FIG. 3A is a vertical section on the line  3 A— 3 A of FIG. 3; 
     FIG. 3B is a vertical section on the line  3 B— 3 B of FIG. 3; 
     FIG. 3C is a view corresponding with FIG. 3 but showing the sheet supporting tray retracted; 
     FIG. 4 is a side elevation of the portion of the receiver embraced by the line  4 — 4  of FIG. 3; 
     FIGS. 5A through 5E are vertically spaced diagrammatic illustrations of the sheet receiving apparatus to receive and stack sheets in an offset relationship; 
     FIGS. 5F through 5J are views corresponding to FIGS.  5 A— 5 E, but showing the sheet receiving apparatus functioning to stack sets of sheets in a non-offset relationship; 
     FIG. 6 is a top plan illustrating a modification of the apparatus provided with a means for stapling the sets in one corner thereof, with the covers removed; and 
     FIG. 7 is a section on the line  6 — 6  of FIG.  7 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     As seen in FIG. 1, a stacker S is mounted on a roll up base B of a standard stacker on which a stacker tray T is mounted for upward and downward movement on belts  1  under the control of a suitable control system which, as is well known, is adapted to progressively lower the tray T as sheets or sets of sheets are stacked thereon during operation of the printer or copier P, as the sets are fed in the direction of the arrow through an infeed  2  into the sheet receiving apparatus R of the present invention. 
     Referring to FIGS. 2 and 3, it will be seen that there are two reversely constructed side paper supports which are selectively connectable to the stacker S by suitable support means  3  and fasteners  4 . Each of the sheet supporting means or structures includes a frame bearing base  5  below which is mounted a support plate  6  adapted to be extended and retracted from beneath the plate  5  by a motor M 1 . A motor M 2 , which is a stepper motor, is adapted to drive inwardly and outwardly joggers  7 . 
     The motor M 1  is reversible and adapted through a pair of racks, or other comparable means, to extend the sheet support plate  6  by gearing  9  and  10 , gear  10  being engaged with the racks  8  so as to cause extension and retraction of the plate  6 . Motor M 2  is adapted to drive gears  11  which are engaged with racks  12 , or other comparable means, so as to extend and retract the jogger  7 . 
     In the preferred form illustrated, the motor driven gear  9  engages the respective gears  10  which are mounted on an external shaft  13  (best seen in FIGS. 3B and 3C) through which an internal shaft  14  extends for extending and retracting the jogger  7  by reverse rotation of motors M 1  and M 2 . 
     Referring to FIG. 3A, the jogger  7  is shown in a retracted position while the plate  6  is shown in an extended position. The plate  6  is grooved at  6   a  to allow the jogger  7  to extend below the sheet supporting top surface of the plate which, as seen in FIG. 3B, is designated  6   b.  Suitable fastenings  15  connect the sheet support plate  6  to a portion of the rack  8  extending downward through a slot  16  in the base plate  5 . 
     A similar structure is at the opposite side of the apparatus from the side shown in FIG.  3 . 
     The mode of operation of the structure, for purposes of receiving and offsetting stacks of sheets ST, is seen by reference to FIGS. 5A through 5E, in which it will be seen that the support plate  6 , at each side of the apparatus, is extended one toward the other so that a stack of sheets is supported thereby, as the sheets exit the copier or printer P. 
     The stacker tray T is independent of the sheet receiving apparatus R and is adapted to progressively move downwardly as sets are stacked thereon. 
     As seen in FIG. 5B, the joggers  7  have been moved toward one another so as to contact and edge align the sheets in the stack which is supported on the extensible and retractable plates  6 . 
     In FIG. 5C, however, the plates  6  are retracted so that the set of sheets is free to gravitate to the top of the previously stacked set in an offset relation, as the stacker tray T has been moved downwardly by the usual stacker tray control means. 
     In FIG. 5D the set of sheets has been allowed by downward movement of tray T to fall in jogged and offset relation to the previously standard set. 
     In FIG. 5E, it will be seen that the sheet supporting plates  6  have again been returned toward one another in preparation for receiving an additional set of sheets. 
     In FIGS. 5F through 5J, the operation of the receiver is shown as functioning simply to receive progressive sets of sheets, jog the sheets into edge alignment and drop the sets, which are stacked one on the other in vertical alignment. 
     Referring to FIGS. 6 and 7, the apparatus is shown as including means for stapling or finishing the sets before they are dropped from the plate  6  onto the stacker tray T. 
     In this embodiment, the supporting structure for the frame plate  5  is shaped so as to accommodate the “STAPLER” and an upper mounting bracket  20  hangs the plate  5  by suitable fastenings  21  and a fastener  4   a  attaches the bracket  20  to the support structure  3 . 
     In addition the bracket  20  provides support for the STAPLER as by means of fastenings  22 . 
     The set of sheets ST, as previously indicated, is movable by the stepper motor M 2  and the jogging members  7 , so that, as shown in FIG. 6, the set ST can be moved into a slot  23  in the stapler for permitting the driving of a staple shown at  24  through the set of sheets when the set is in the broken line position of FIG.  6 . Thereafter, the jogging members  7  may be returned to cause movement of the set ST from the stapler slot or throat back to a position at which the plates  6  may be opened to deposit the sets on the stacker tray T in either the offset or non-offset relation, but preferably with the stacked set offset to minimize the effect of the staple thickness on the ability of the stacker tray to hold a maximum of stacked sets. 
     In the embodiment, as illustrated in FIGS. 6 and 7, it will be seen that the mechanism for extending and retracting the plate  6  and extending and retracting the joggers  7  is the same as described previously. It is also possible within the purview of the invention to modify the jogging structure to provide a single jogging member  7  extendable and retractable relative to the apparatus at the opposite sides of the inlet to the receiver. 
     Other changes and alterations may be made in the structure or the arrangement of parts of the apparatus.