Patent Publication Number: US-5895036-A

Title: Finishing apparatus

Description:
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT 
     The present invention relates to a finishing device for stapling whenever a stack of predetermined number of sheets is ejected from an image forming device, such as a copying machine and laser printer, and piling the stapled stack on a piling tray. 
     Heretofore, the finishing device of this type has been widely known to be disposed in parallel with the image forming device in a horizontal direction or in a vertical direction, wherein sheets from the image forming device are sequentially piled on a tray in numerical order, and an edge portion thereof is stapled at one place. 
     In a stapling unit of the device, a cartridge loaded with needles is detachably provided to a unit frame, and when the needles are used up, the cartridge is detached to make an exchange. 
     Incidentally, in the above described type finishing device, a cartridge unit is drawn out of a stapling position of the device for exchange of the cartridge to thereby exchange the cartridge outside a stapling area of the device. 
     Accordingly, there have been defects such that the stapling unit or a block member for mounting thereof is movably provided to the device, so that the finishing device has been complicated and large-sized, and a space for exchanging the cartridge has to be provided on a side portion of the device. 
     The present invention is to provide a finishing device wherein there is no necessity for taking a stapling unit out of the device for exchange of needles. 
     SUMMARY OF THE INVENTION 
     In order to solve the above-described problem, a finishing device of the present invention includes a sheet transferring path for guiding a sheet from an image forming device to a piling tray by substantially vertically deflecting the sheet in either upper or lower direction of the device; a tray for temporarily piling and holding sheets, as a stack, from the sheet transferring path; and a stapling unit disposed between the tray and the sheet transferring path so that an edge on an upstream side of the sheets on the tray is bound. The stapling unit is structured such that a cartridge loaded with stapling needles can be attached or detached from a back surface side facing a sheet transferring path side, and at least a part of sheet guides for constituting the sheet transferring path can be freely opened and closed so that the back surface side of the stapling unit can be exposed outside the device. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a vertical section view of an essential part showing a finishing device of the present invention; 
     FIG. 2 is a plan view of the essential part of the finishing device; 
     FIG. 3 is an enlarged view of a sheet ejecting portion of the finishing device; 
     FIG. 4 is an enlarged side view of a stapling device; 
     FIG. 5 is a diagrammatic section view of an image forming apparatus; and 
     FIG. 6 is a diagram showing a part of guide plates. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
     Next, an embodiment of a sheet ejecting device of the present invention applied to a finishing device installed on an upper surface of an image forming device is described referring to the accompanying drawings. 
     In FIG. 5, an image forming apparatus 1 includes a main image forming device 2, such as a copying machine and laser printer, a finishing device 3 installed on the main image forming device 2, and an adaptor device 4 for connecting the main image forming device 2 and the finishing device 3. 
     The main image forming device 2 includes a sheet feeding cartridge 5 for accommodating therein a plurality of sheets; an image forming device 7 having a transfer printing drum 6 for transfer-printing an image on the sheet from the sheet-feeding cartridge 5; and a transferring portion 8 for supplying the sheet on which the image has been set to the finishing device 3. The sheet P1 sent out from the transferring portion 8 is supplied to the finishing device 3 through the adaptor device 4. 
     Incidentally, it is also possible to form an image forming apparatus wherein functions of the finishing device 3, which are described later, are built in the main image forming device 2 so that the main image forming device 2 and the finishing device 3 are included in one device. 
     The finishing device 3 is connected to the main image forming device 2 through the adaptor device 4, and includes a second deflecting path 9 for deflecting the sheet P1 from the main image forming device 2; a first sheet transferring path 10 for guiding the sheet from the second deflecting path 9 in a substantially vertical direction; a second sheet transferring path 11 having a deflecting portion for guiding the sheet from the first sheet transferring path 10 in a substantially horizontal direction; a processing space 12, also used as a sheet ejecting path, formed between an exit terminal on a sheet ejecting downstream side of the second sheet transferring path 11 having the deflecting portion and a sheet ejecting port 3a of the finishing device 3; and a second sheet ejecting path 13 branched from a border portion between the first sheet transferring path 10 and the second sheet transferring path 11 having the deflecting portion. 
     More specifically, the finishing device 3 includes a staple processing path wherein the sheet P1 passes through the second deflecting path 9, the first sheet transferring path 10, and the second sheet transferring path 11 having the deflecting portion to be guided to the processing space 12, and makes one and half return trips in the processing space 12, the sheet P1 is guided to the sheet ejecting port 3a; a non-processing path wherein after the sheet P1 passes through the second deflecting path 9, the first sheet transferring path 10 and the second sheet transferring path 11 having the deflecting portion, the sheet P1 passes through the processing space 12 to be guided to the sheet ejecting port 3a; and a non-processing path wherein the sheet P1 passes through the second deflecting path 9, the first sheet transferring path 10 and the second sheet ejecting path 13. Also, the second deflecting path 9, the first sheet transferring path 10 and the second sheet transferring path 11 having the deflecting portion form an accommodating space 16 for accommodating a stapling device 15 therein by detouring the entire path along a rear shape of a housing 14 of the finishing device 3 in a substantially U-character shape. 
     The second deflecting path 9 is formed of a pair of opposed guide plates 17, 18 with a space therebetween so that the sheet P1 can pass therethrough. Also, at a starting edge portion of the second deflecting path 9, as shown in FIG. 1, are provided a sheet detecting sensor 20 for detecting forward and rear ends of the sheet P1 transferred from the adaptor device 4; and a pair of sheet feeding rollers 21, 21 provided at two portions in a width direction (refer to FIG. 2) of the sheet P1 so that the sheet can be transferred on a downstream side of the second deflecting path 9. 
     The first sheet transferring path 10 is formed of a guide plate 22 opposed to the guide plate 17 with a space therebetween so that the sheet can pass therethrough. Also, the first sheet transferring path 10 is provided, in the middle portion thereof, with a pair of transferring rollers 23, 23 for transferring the sheet from the second deflecting path 9 on the downstream side in the transferring direction. 
     The second sheet transferring path 11 having the deflecting portion is formed of a guide plate 24 opposed to the guide plate 22 with a space therebetween so that the sheet can pass therethrough. Also, at a path terminal portion of the second sheet transferring path 11 having the deflecting portion are provided plural pairs of transferring rollers 25, 25, 25 for transferring the sheet from the first sheet transferring path 10 on a downstream side in an ejecting direction; and a sheet detecting sensor 26 for detecting the forward and rear ends of the sheet to be ejected in the second sheet transferring path 11 having the deflecting portion. Also, at a border portion between the first sheet transferring path 10 and the second sheet transferring path 11 having the deflecting portion is provided a switching device 27 for switching a transferring direction of the sheet to either the second sheet transferring path 11 having deflecting portion or the second sheet ejecting path 13. 
     After the sheet detecting sensor 20 counts the number of transfer printing sheets set on a control panel or computer side of the main image forming device 2, when the sheet detecting sensor 26 detects the rear ends of the sheets to be ejected corresponding to the number of the detected count-up sheets, a command signal for driving the stapling device 15 is outputted after a predetermined time passes. 
     In the present embodiment, there is shown an example wherein the finishing device 3 itself determines a timing for stapling process based on information of the sheet detecting sensor 20 to thereby drive the stapling device 15. However, naturally, there may be considered a system wherein the image forming device 2 itself knows the timing, and sheet number counting and stapling process decision are also carried out in the image forming device 2 itself to thereby output a stapling command to the finishing device 3. Further, a signal for driving the stapling device 15 may be produced by a manually operated button or the like (not shown). 
     The switching device 27 includes crank arms 28, 29 driven in contraposition with movement of the stapling device 15 along a width direction of the sheet, and a switching lever 30 rotated by the movement of the crank arms 28, 29. 
     The processing space 12 is located under an exit terminal of the second sheet transferring path 11 having the deflecting portion, and formed over a stapling tray 31 obliquely extending toward the sheet ejecting port 3a from its lower end overlapping the exit terminal of the second sheet transferring path 11 having the deflecting portion. Also, in the vicinity of the sheet ejecting port 3a of the processing space 12 is provided a sheet ejecting process portion 32. 
     Also, under the sheet ejecting portion 32 is provided a piling tray 33 projecting upward from an outer wall of the housing 14 in an inclined state. The piling tray 33 is vertically moved through vertical movement of rollers 35, 35 provided to a bracket 34 fixed to a base portion of the piling tray 33 along a vertically extending guardrail 36, and an elevating device 37 for the vertical movement is provided at an outer portion of the housing 14. 
     The stapling tray 31 is provided with a pair of guides 38, 38 for aligning both sides of the sheets from the second sheet ejecting path 11, and at least one of the pair of guides can be displaced in a sheet width direction according to a size of the sheet. Also, the stapling device 15 is accommodated in an accommodating space 16 formed to make a detour along the second deflecting path 9, the first sheet transferring path 10 and the second sheet transferring path 11 having the deflecting portion so that the stapling device 15 is positioned between the lower end of the stapling tray 31 and the first sheet transferring path 10. Further, the stapling tray 31 is provided with a measuring sensor 39 for detecting a sheet loading capacity. Incidentally, the detecting capacity of the measuring sensor 39 is set according to an allowable amount to be bound by the stapling device 15, and when sheets are accumulated over the allowable amount, no staple binding is carried out. Also, at the lower edge of the stapling tray 31, as shown in FIG. 3, is provided a paddle 40. 
     The paddle 40 is rotated (counterclockwise in FIG. 3) when it is confirmed that a predetermined time has passed after the sheet detecting sensor 26 detects passage of the sheet, and the rotation of the paddle 40 drops the sheet so that the sheet ejected on the stapling tray 31 and slid down by its own weight toward the stapling device 15 positively abuts against a stopper 90 and a staple controlling wall 15b to thereby align the rear end of the sheet. 
     The sheet eject processing portion 32 includes a plurality of sheet eject driving rollers 41 rotatably provided to an upper end of the stapling tray 31, a plurality of arm-type driven rollers 42 provided to contact and separate from the sheet eject driving rollers 41, and rotation arms 43 coaxially provided with the sheet eject driving rollers 41. 
     The arm-type driven rollers 42 approach (the state as shown in FIG. 1) or separate (the state as shown in FIG. 3), with respect to the sheet eject driving rollers 41 according to the ejecting state of the sheet. When the sheets are bound by the stapling device 15, the arm-type driven rollers 42 approach the sheet eject driving rollers 41 to sandwich a stack of sheets therebetween and to eject the same from the sheet ejecting port 3a onto the piling tray 33. Incidentally, the approach and separation of the arm-type driven rollers 42 are carried out in such a manner that, as shown in FIG. 3, an engaging pawl 44a is projectively provided to an arm 44 rotatably holding the arm-type driven rollers 42, and one end of an L-character shape lever 45 is engaged with the engaging pawl 44a and an eccentric cam 46 abuts against the other end side of the lever 45 to thereby control the rotation of the eccentric cam 46. In other words, the L-character shape lever 45 is rotated according to a rotation angle of the eccentric cam 46 to thereby vertically move the engaging pawl 44a, and through the vertical movement of the engaging pawl 44a, the arm 44 is rotated. 
     The rotation arm 43 has a substantially L-character shape provided with rotatable rollers 47, 48 on both edges thereof. The rotation arm 43 is rotated such that a worm gear 50 is rotated through driving of a motor 49, and a rotation gear 51 receives rotation of the worm gear 50 to thereby rotate the rotation arm 43. Incidentally, although the sheet eject driving roller 41 and the rotation gear 51 are coaxially provided, they are rotated independently. 
     The second sheet ejecting path 13 is formed of opposed guide plates 52, 53 with a space therebetween so that the sheet can pass therethrough. Also, at a path terminal portion of the processing space 12 are provided a pair of sheet ejecting rollers 54 for ejecting the sheet through an auxiliary sheet ejecting port 3b; and a loading capacity detecting sensor 56 for detecting a loading capacity of the sheets piled on an auxiliary piling tray 55 provided to be opened and closed at an upper portion of the housing 14 extending, in an inclined state, from a lower portion to an upper portion of the auxiliary sheet ejecting port 3b. 
     To the second sheet ejecting path 13 is supplied the sheet from a terminal portion of the first sheet transferring path 10 through switching of the sheet transferring path by the switching lever 30 since the crank arms 28, 29 are actuated in association with shift of the stapling device 15 as the stapling device 15 is shifted to its home position when it is not used. 
     When the loading capacity detecting sensor 56 detects a maximum loading capacity, it actuates the switching lever 30 so that the remaining sheets are piled on the piling tray 33. Incidentally, when the stapling device 15 is not used the sheets may be piled on the piling tray 33, and when a piling capacity on the piling tray 33 becomes maximum, the remaining sheets may be piled on the auxiliary piling tray 55. 
     The auxiliary piling tray 55 is rotatably provided to the housing 14 so that an upper portion of the stapling tray 31 can be opened. Incidentally, the sensors 26, 39 also function as sheet-jam detecting sensors. In case the sensors 26, 39 detect a sheet jam, the auxiliary piling tray 55 is opened as shown by single-dotted chain lines in FIG. 1 to thereby release the sheet jam. Incidentally, sheet jams in the second deflecting path 9 and the first sheet transferring path 10 can be detected by the sheet detecting sensor 20, and the sheet jams can be released by opening a cover 14a. 
     Further, in case the auxiliary piling tray 55 is provided with a supporting member, such as a wire, to a position as shown by the single-dotted chain lines in FIG. 1, the auxiliary piling tray 55 can also be applied to a large size of ejected sheets which can not be processed by the piling tray 33. 
     Incidentally, each of the pairs of rollers 21, 23, 25, 54 includes a driving roller and a driven roller. The pair of rollers 54 is rotated through driving of a motor 57 and, at the same time, the driving rollers of the respective pairs of the rollers 21, 23, 25 are rotated through plural pulleys and belts. 
     The stapling device 15, as shown in FIG. 4, includes a bench unit 58 for bending a needle and a driving unit 59 for inserting the needle into sheets. A rotational center position of the driving unit 59 is fixed with respect to a bench frame 60 surrounding the bench unit 58, and the driving unit 59 is rotatably provided to a pin 61 as the rotating center. The rotating power of a driving motor 62 is transmitted to a three-step sequence gear 63. 
     The sequence gear 63 is provided with a projecting gear pin 64 for controlling opening and closing of the bench unit 58 by the driving unit 59. 
     A driver 65 for inserting, from a lower side with respect to the stack of sheets on the stapling tray 31, a needle appearing outward from a forward edge of a stapling cartridge 15a loaded with a plurality of needles inserts the needle into an inserting portion 67 of the driving unit 59 in association with a vertical movement of a driving arm 66. The driving arm 66 is connected to the gear pin 64 through a slot 66a with the rotating center thereof as an axis, and makes one vertical movement for one rotation of the sequence gear 63. 
     On the other hand, the stapling device 15 is movable in a width direction of the sheet by a moving device 68 so that sheets can be bound according to, for example, their sheet width, binding position or positions. Also, the cartridge 15a built in the stapling device 15 can be attached or detached by opening a back cover 14a (refer to arrow marks) of the housing 14, and the central portions of the guide plates 17, 18, 22 are open so that the cartridge 15a can be attached or detached therethrough. More specifically, when the cover 14a is opened, the guide plates 18, 22 are exposed as shown in FIG. 6, and an opening is provided to the guide plate 18. In case the needles are exchanged, the stapling device 15 is moved to the opening position of the guide plate 18; the cover 14a is opened as shown by two-dotted chain lines in FIG. 1; and the cartridge 15a is taken out of the opening of the guide plate 18 for exchange. 
     Incidentally, each of the trays 31, 33, 55 is disposed with an upward inclination in at least a portion thereof so that a rear end of an ejected sheet is located at a position lower than that of a forward end thereof to thereby align the rear end by its own weight. 
     In the structure as described above, in case a stack of sheets is bound by the stapling device 15, the sheet P1 ejected from the main image forming device 2 is transferred to make a detour through the second deflecting path 9, the first sheet transferring path 10 and the second sheet transferring path 11 having the deflecting portion by driving of the pairs of the transferring rollers 21, 23, 25 and guides of the guide plates 17, 18, 22, 24. At this time, the arm-type driven rollers 42 are separated from the sheet eject driving rollers 41. 
     And, after the rear end of the sheet to be ejected passes through the pair of the transferring rollers 25 provided at the terminal portion of the second sheet transferring path 11 having the deflecting portion, and the forward end of the sheet ejected on the stapling tray 31 is once projected outside from a space between the sheet eject driving rollers 41 and the arm-type driven rollers 42 by a forcibly ejecting power, the sheet is guided in a reverse direction by its own weight, both edges in the width direction of the sheet abut against a pair of guides 38, 38, and the rear end of the ejected sheet abuts against a stopper 90 and a staple controlling wall 15b through rotation of the paddle 40 to thereby be aligned, respectively. 
     When the sheet detecting sensor 26 detects in a predetermined time that the sheet detecting sensor 20 counts the predetermined number of sheets; the last sheet of the counted-up sheets is transferred onto the stapling tray 31; and alignment of the sheets is completed, the paddle 40 is rotated to drop the last sheet onto the stapling device 15. Thereafter, a stack of the transfer-printed sheets is bound at the stapling device 15. 
     At this time, in the stapling device 15, since the transfer-printed surfaces of the sheets face the side of the stapling tray 31 (according to a situation of the sheets ejected from the main image forming device 2), the stack of sheets is stapled from a lower side thereof. 
     At a time point that the stack of sheets is stapled, since the arm-type driven rollers 42 have already approached the sheet eject driving rollers 41 (the state as shown in FIG. 1) and gripped the stack of sheets, the stack of sheets is not collapsed by the stapling process. 
     Although the stopper 90 can be rotated by a shaft, since the stopper 90 is engaged with the shaft through a coil spring, when the stopper 90 is rotated, it abuts against an upper surface of the stapling device 15, so that the coil spring is defeated to thereby stop the stopper 90. The two stoppers 90 are provided at two positions of the shaft, so that even if the stapling device 15 stops at any position, the rear end of the sheet can be supported by at least one of the stoppers 90 and the staple controlling wall 15b. 
     Further, the stapled stack of sheets is piled on the piling tray 33 through rotation of the arm-type driven rollers 42 which have approached the sheet eject driving rollers 41 (the state as shown in FIG. 1) and gripped the stack of sheets therewith. Thereafter, processes corresponding to the number of stacks of sheets are repeated, and as a loading quantity of the stacks of sheets increases, the piling tray 33 is moved downward to thereby allow a large number of stacks of sheets to be piled thereon. 
     Generally, as it is equally true in the case of the stapling device 15, the driving unit 59 for inserting the needle occupies an overwhelming volume with respect to the bench unit 58 for bending the needle. Therefore, the stapling tray 31 and stapling device 15 which can not be separated so far from the pair of transferring rollers 25 are disposed in a compact relationship, and when the sheets are substantially vertically brought into the finishing device 3 and the printed surfaces thereof face the piling side of the finishing device 3, since the needle is inserted from a lower side thereof, the path system according to the present invention is compact and optimum. 
     On the other hand, in case a staple binding is not carried out, the stapling device 15 is moved back to its home position to thereby rotate the levers 28, 29, and the switching lever 30 is rotated through the rotation of the levers 28, 29 to allow the second sheet ejecting path 13 to communicate with the first sheet transferring path 10. 
     The sheets ejected from the main image forming device 2 are transferred through the second deflecting path 9, the first sheet transferring path 10 and the second paper ejecting path 13 by drivings of the pairs of transferring rollers 21, 23, 54, and successively piled on the auxiliary piling tray 55. 
     As described above, in the finishing device 3 according to the present invention, the detachable cartridge 15a can be easily attached or detached by opening the cover 14a, and further it is not required to take the stapling unit out of the device for exchanging the needles.