Note: Descriptions are shown in the official language in which they were submitted.
R/820 1 9
--1--
This invention relates to copy finishing apparatus for collecting sheets
into sets, and particularly to such apparatus including means for binding the
5 sets.
A copy ~inishing apparatus according to the invention comprises a first
support surface for compiling sheets delivered serially thereto into sets, a
second support surface arranged under said first support surface for
receiving and stacking sets from said first support surface, and transport
10 means for conveying sheets around an inversion or direction reversing path
between said support surfaces.
Preferably one or both of said support surfaces is arranged at an angle
to the horizontal. Thus, the first or compiling surface suitably slopes
downwardly towards an end registration stop which is retractable for
conveying compiled sets to the second or stacking surface. The angle of the
compiling surface may for example be 35 to 45, preferably 40. In a
preferred form, both surfaces slope in the same direction and the transport
extends between the lower end of the compiling surf ace and a posi tion
spaced above the lower end of the stacking surface.
The apparatus preferably includes means for binding sets compiled on
the first support surface in which case corner registration means should be
provided for registering the sheets against end and side registration stops.
The sheets may be conveyed onto the compiling surface from the end
opposite the end registration stop (forward registration) or from the
25 opposite direction (reverse registration)~ In the latter case where the
registration means is arranged over the support surface the sheet should be
conveyed onto the support surface over the registration means and the
support surface should slope downwardly in the oppGsite direction towards
the end registration stop so that sheets delivered onto the surface ~eyond
30 the registration means in the one direction will move under gravity beneath
ihe registration means. Where means is provided for binding sets compiled
on the compilin~ surface and means is also provided~~for~~ejecting such sets
from the compiling surface, sheets are conveyed onto the compiling surface
over these elements as well.
;
....
9~
In a preferred configuration a path for single sheets extends from the
input of the apparatus directly to the second support surface.
In order that the invention may be more readily understood, reference
will now be made to the accompanying drawings, in which:-
Figure 1 is a schematic front view of a photocopier incorporating a
recirculating document handler and finis~ier according to the invention,
Figure 2 is a front view of the finisher shown in Figure 1,
Figure 3 is a rear view of the finisher,
Figure 4 is a perspective view from above of the finisher,
Figure 5 is a schematic rear view showing a by-pass path for sheets,
Figure 6 is a perspective view from above of the compiler tray of the
finisher,
Figure 7 is a perspective view of the stapler mechanism of the
finisher,
Figures 8 to 10 show the operation of the stapler drive mechanism
under varying conditions,
Figure 11 is a front view of the eject mechanism showing the positions
of the elements during sheet compiling,
Figure 12 is a view like that of Figure ll showing the positions of the
elements during set ejection and also illustrating the eject path for the sets,
Figure 13 is a schematic perspective view of the mechanism as shown
in Figure 11,
Figure 14 is a partly exploded view of the set offsetting stacking tray,
and
~5 Figure 15 shows schematically the drives for the finisher.
Referring first to Figure 1 there is shown a xerographic copying
machine incorporating a recirculating document handler 40 and a finisher 60
according to the present invention. The machine includes a photoreceptor
drum 1 mounted for rotation (in the clockwise direction as seen in Figure 1)
to carry the photoconductive imaging surface of the d~m sequentially
through a series of xerographic processing stations: a charging station 2, an
imaging station 3, a development station 4, a transfer station 5, and a
cleaning station 6.
The charging station 2 comprises a corotron which deposits a uni~orm
electrostatic charge on the photoreceptor. A document to be reproduced is
positioned on a platen 13 and scanned by me ;ns of a moving optic~l scanning
system to produce a flowing light image on the drum at 3. The optical
image selectively discharges the photoconductor in image configuration,
whereby an electrostatic latent image of the object is laid down on the drum
surface. At the development station 4, the electrostatic latent image is
5 developed into visible form by bringing into contact with it toner particles
which deposit on the charged areas of the photoreceptor. Cut sheets of
paper are moved into the transfer station 5 in synchronous relation with the
image on the drum surface and the developed image is transferred to a copy
sheet at the transfer station 5, where a transfer corotron 7 provides an
10 electric field to assist in the transfer of the toner particles thereto. The
copy sheet is then stripped from the drum 1, the detachment being assisted
by the electric field provided by an a.c. de-tack corotron 8. The copy sheet
carrying the developed image is then carried by a transport belt system 9 to
a fusing station 10.
Aft~r transfer of the developed image from the drum, some toner
particles usually remain on the drum, and these are removed at the cleaning
station 6. Af~er cleaning, any electrostatic charges remaining on the drum
are removed by an a.c. erase corotron 11. The photoreceptor is then ready
to be charged again by the charging corotron 2, as the first step in the next
20 copy cycle.
The optical image at imaging station 3 is forrned by optical system 12.
A document (not shown) to be copied is pla~ed on platen 13 by the document
handler 40, and is illuminated by a lamp 14 that is mounted on a scanning
carriage which also carries a mirror 16. Mirror 16 is the full-rate scanning
25 mirror of a full and half-rate scanning system. The full-rate mirror 16
reflects an image of a strip of the document to be copied onto the half-rate
scanning mirror 17. The image is focussed by a lens 18 onto the drum i9
being deflected by a fixed mirror 19. In operation, the full-rate mirror 16
and lamp 14 are moved across the machine at a constant speed, while a~ the
30 same time the half-rate mirrors 17 are moved in the same direction at half
that speed. At the end of a scan, the mirrors are in the position shown in a
broken outline at the left hand side of Figure 1. These movements of the
rnirrors maintain a constant optical path length, so as to maintain the image
on the drum in sharp focus throughou~ the scan. Al~ernatively the optical
35 system 12 may be fixed in position and the document scanned by being
advanced across it by the documen - handler 40 as described below.
-- 4 --
At the development station 41 a magnetic brush developer system 20
develops the electrostatic latent image. Toner is dispensed from a hopper
21 by means of a rotating foam roll dispenser 22, into developer housing 23.
Housing 23 contains a two-component developer mixture comprising a
5 magnetically attractable carrier and the toner, which is brought into
deYeloping engagement with drum 1 by a two-roller magnetic brush
developing arrangement 24.
The developed image is transferred, at transfer station 5, from the
drum to a sheet of copy paper (not shown) which is delivered into contact
10 with the drum by means of a paper supply system 25. Paper copy sheets are
stored in two paper trays, an upper, main tray 26 and a lower, auxiliary tray
27. The top sheet o~ paper in either one of the trays is brought, as required,
into feeding engagement with a common, fixed position, sheet separator/
feeder 28. Sheet feeder 28 feeds sheets around cùrved guide 29 for
15 registration at a registration point 30. Once registered, the sheet is fed into
contact with the drum in synchronous relation to the image so as to receive
the image at transEer station 5.
The copy sheet carrying the transferred image is transported, by
means of vacuurn transport belt 9, to fuser 10, which is a heated roll fuser.
20 The image is fixed to the copy sheet by the heat and pressure in the nip
between the two rolls of the fuser. The final copy is fed by the fuser rolls
along output guides 31 to the input nip 65 of the finisher 60.
After transfer of the developed image from the drum to the copy
sheet, the drum surface is cleaned at cleaning station 6. At the cleaning
25 station, a housing 33 forms with the drum 1 an enclosed cavity, within which
is mounted a doctor blade 34. Doctor blade 34 scrapes residual toner
particles off the drum, and the scraped-off particles then fall into the
bottom of the 51ousing, from where they are removed by an auger.
As mentioned above, sheets 5 may be fed from either the m~in tray 26
30 or the auxiliary tray 27. The auxiliary tray is of larger size than the main
tray, enabling a wide choice of paper sizes and types to be fed from it. The
ttays are physically located in the lower part of the machine below the
photoreceptor drum 1.
As shown in Figure 1 a recirculation document handler 40 is prsvided
35 for feeding documents to be copied to the platen 13 of ~he photocopier. The
document handler include a storage tray 41 for the documents to be copied
and document circulating means for delivering the documents in turn to the
platen from the storage tray and for returning the documents to the tray,
whereby the documents may be circulated and recirculated in sequence past
the platen for repeated copying (precollation mode). The documents may
5 ei ther be transported across the platen at a constant velocity past the
optical system 12 of the photocopier which is held stationary in the solid
line position shown, or instead they may be registered on the platen prior to
copying and the stationary document exposed by scanning the optical system
12 across the document as described above. For this prupose a registration
10 member or gate 39, which can be moved in and out of sheet blocking
position at the registration edge of the platen by means of a conventional
solenoid type actuator, is provided for registering the document in
stationary position on the platen 13 while the optical system 12 is scanned
across the document. When the document is registered on the platen, the
15 document handler can be operated in so-called stacks mode wherein each
document is copied a plural number of times during a single delivery to the
platen.
The document handler comprises, in addition to the storage tray 41, a
document separator/feeder 42, a pre-platen transport 43 for conveying
20 documents to the platen, a platen transport 44 and a post-platen transport
45 by which documents are returned to the storage ~ray.
The document storage tray 41 is mounted oYer the platen 13 and slopes
upwardly towards the separator/feeder 42; it is adjustable to accommodate
different document sizes.
Sheet separation and acquisition is accornplished by a vacuum belt
corruga~ion feeder (V(::~) 42 using flotation pressure differences between
the bottom sheet and the sheets above, sheet corrugation and vacuum, a
parabolic contour pocket being cut out at the lead edge of the tray 41 and
dished down in the manner shown and described in ~S Patent No. 4275877.
30 Documents placed in the tray, bridge this gap and form a flotation pocket.
Transport belts 46 surface through the document tray within the contour
pocket. Document stack flotation is accomplished by a frontal assault of air
from an air knife 47. The air jet impinges on the tray just in front of the
lead edge of the document stack; this permits \~olumetric flow expansion of
35 air within the pocket contour of the tray and also riffles the front edge of
the documents ~.~ allow a differential pocket of air between the bottom
- 6 -
sheet and sheet 2. This assists in the acquisition, separation and feeding of
the bottom document.
The pre-platen and post-platen transports 43, 44 consist of pairs of nip
rolls and inner and outer inversion guides as shown and the platen transport
5 ~5 comprises a single white, wide friction drive belt ~8 entrained over input
and output transport rollers 49. The document is transported across the
platen 3 by the belt 48. Three gravity rolls apply a nip between the belt 4
and platen 13 and maintain drive across the platen.
The document handler may be operated ~s described above either in
10 pre-collation (or sets) mode in which the pages of a document are copied
one at a time in serial number order or in post-collation (or stacks) mode in
which multiple copies of each document sheet are made before the next
document sheet is copied. In accordance with the invention a copy sheet
fînishing apparatus 60 capable of handling output for the document handler
15 in both these modes is shown in Figure 1.
The finisher 60 includes an offsetting catch tray or output tray 100
and may be operated to perform the following functions:
(a) to compile, regisfer and corner staple sets of copies as they are
produced and transport the stapled sets into the offsetting catch tray
1007 and
(b) to deliver copies direct to the offsetting catch tray 100 where the
sheets may be compiled in offset sets.
- In a variation of (a) the stapling step may be omitted.
The finisher receives copy sheets from the processor at input nip 65
25 and conveys them to the offsetting catch tray 100 either directly along a
path 61 or, via a compiler tray 62 in which they are registered and stapled,
along a path 63. The direction of the sheets is determined by a diverter 64
located directly following the finisher input nip rolls 65a, 65b and which is
operated in response to a signal frorn the processor initiated by the
30 operator.
The path 63 comprises upper and lower guides 63a, 63b and includes
two further sets of nip rolls 67, 68 which accelerate the sheets into the
compiler tray 62. The sheets are corner registered against a retractable end
registration gate 69 and a side registration gate 70 at the front of the
3~ machine by gravity and a paddle wheel 71, represen~ed in Figure 1 by a
broken ellipseO Se~s compiled in the tray 62 are corner stapled by a stapler
72. Stapled sets are driven from the tray 62 by retracting the ga~e 69 and
lifting the set against a pair of drlven eject rolls 73 by means of a pair of
idler rolls 74 mounte on one end of pivoted arM 75 which carries the gate 69
at its other end.
~hus the sheets are conveyed into the compiler tray in a first direction
(from right to left in Figure 1) and their trail edges registered by being
conveyed against the end registration gate 69 in the opposite direction (from
leEt to right in Figure 1). The path 63 extends over the paddle wheel 71 and
the eject rolls 73 and the sheets drop by gravity towards the end registration
gate 70 since the tray 62 slopes downwardly in that direction at an angle of
between 35 and 45 degrees. In the embodiment of Figure 1 the angle is 3~
to 42 degrees, preferably 40 degrees. Essentially the tray angle must be
sufficient for the sheee~s to drop by gravity into the influence of the paddle
wheel 71.
The sets are carried into the offsetting catch tray 100, which is
arranged beneath the compiler tray 62, around a large driven, rigid sun roll
76 with the aid of three driven, compliant planet rolls 77, 78, 79 and outer
guides 80, 81. Thus as the sets are conveyed to the offsetting catch tray
100 they are inverted and their direction reversed. The catch tray 100 itsel
slopes downwardly in the same direction as the compiler tray 62 suitably at
an angle of 35 to 40 degrees, preferably 40 degrees.
In sets copying mode, a documen~ set to be copied is placed face up in
the document handler tray 41 so that the pages of the document are copied
in reverse order. Thus, copy sheets are delivered to the compiler tray of the
finisher in the order n-1. The copy sheets are received face-up so that the
assembled set is in page number order and are fed through the copier long
edge first so that the top of the page is at the front side of the machine.
Accordingly the top left-hand corner of the set is arranged in the
registration corner and is stapled. Thus sets stapled in the compiler tray 62
are received face-down in ~he catch tray 100 with the stapled corner at the
upper front of the tray.
The above described configuration provides a compact finisher in
which the extent to which the finisher projects beyond the processor is kept
to a minimum. At the same time it permits sheets which do not need to be
stapled to be fed directly ~o the catch tray 100.
Thus, where stapling is not required sheets are directed along path 62
into engagement with the roller 76 and driven into the tray 100 with the aid
of driven foam rolls 78, 79. The tray 100 may be offset sideways between
sets to provide visual and physical separation between the sets.
The finisher 60 will now be described in greater detail.
Sheets from the fuser 10 of the processor enter the finisher through
the input nip rolls 65 which comprise a lower steel roll 65b incorporating a
one-way or overrun clutch with a pair of rubber bands thereon and a pair of
upper idler acetal rolls 65a. Drive to the lower rolls 65b (and to all driven
rolls of the finisher) is from the processor output spur gear (not shown). The
rolls 65 assist in driving the copies to the diverter 64, and beyond. The
diverter 64 extends across the paper path and has the cross-section shown in
Figure 1. It is operated by a solenoid 91 (Fig. 4) through a linkage 92. The
solenoid is energised to direct sheets along path 63 into the compiler 62.
The upper transport path 63 comprises upper and lower sheet metal
guides 63a, 63b and the two further sets of nip rolls 67, 68. These comprise
upper idler acetal rolls 67a, 68a and lower driven polyurethane rolls 67b,
68b. In order to project the sheets positively onto the compiler tray 62,
over the paddle wheel 71 and eject roll 73, the nip rolls 67, 68 are driven at
a faster rate than the rolls 65. The one-way clutch in the lower roll 65b
prevents the copies from being torn or scrubbed. The idler rolls 67a, 68a as
well as the input idler rolls 65a are mounted on the upper guide plate 63a
which is hinged from the back of the finisher for jam access. The nip roll
sets 65, 67, 68 serve to corrugate the copy sheets and the idlers are fixed to
the plate 63a by snap-on flexures.
On reaching the compiler tray 62 the copy sheets are reverse corner
registered against end registration stops 69 and side registration plate 70 at
the front of the machine by a driven 3-bladed paddle wheel 71 (Figures 2
and 6). The paddle wheel is straight-bladed and is made of polyurethane.
30 For improved registration the blades flip down on to the sheets from a
restraining plate 71a.
The stapler 72 is arran8ed over the registration corner as shown in
Figure 6 to insert a staple through that corner of the set. The stapler is
actuated when the processor logic detects that a comple~e set has been
35 delivered to the compiler tray 62. The stapler inserts staples at an angle of 20 to the long edge of the setO
3~i
Referring to Figures 7 to 10, the stapler 72 is a standard desk top
stapler with a conventional head 101 and passive clincher-(not shown). It has
a capacity of 160 staples and can staple up to 25 x S0 gm. sheets. Drive to
the stapler is by a motorised cam 103, a cam lever 104, a staple head lever
5 105 and a connectlng shaIt 106. This arrangement allows the cam drive to
be positioned at the rear of the machine although the stapler is at the front.
Adjustment for the staple head lever position is provided by a knuckle joint
in the cam lever 104. The stapler is driven by a separate AC: motor/gearbox
107 (Fig. 7).
A load limiting device is incorporated into the cam lever 104 ~o (a)
accommodate varying set thicknesses presented to the stapler and (b) enable
the cam 1~3 to rotate in the event of seizure or staple jam. This device
comprises a bracket 108 pivoted to the cam lever 104 and connected to it
through a compression spring 109. The cam follower 103a is mounted on the
15 bracket 108 and relative movement of the bracket 108 and lever 104 limits
the force applied by the staple head lever. Thus, if the staple head is closed
before the cam 103 has completed its cycle, excess movement is absorbed
by the cam lever bracket 108 as shown in Figure 10. The load limiting
spring 109 prevents the bracket 108 from pivoting prematurely.
Located just above the back edge of the cam lever bracket 108 is a
micro-switch 110. As the lever/bracket assembly moves up and down
electrical continuity through the microswitch is interrupted. This signal is
used to monitor cam rotation and may assist in staple jam detection.
Return of the stapler head to an open position after each stapling
operation is assisted by a spring 111 attached between the bracket 108 and
the finisher frame and a spring integral with the stapler head.
Staple levels in the magazine are monitored by a low staple sensor (not
shown) activated when only twenty four staples remain. This senso~ is an
optical sensor consisting of an infra-red source and a detector aligned with
30 holes through the staple rail. A signal from the sensor allows the processor
logic to assess how many sets are outstanding against the ongoing job and
act accordingly.
A solenoid 114 (Fig. 3) rnounted under the compiler tray 62 acts on
pivoted arm 75 which as shown in Figures 11 to 13 comprises levers 112 and
35 113. I ever 112 is attached to gate 69 and through an intermediate lever
112a operates a lever 113 carrying the eject (kick-out) idler rolls 74. During
- 10 -
compiling and stapling the rolls 74 and gate 69 are as shown in Fig. 11.
Once the stapling operation has been completed, the solenoid 114 is
energised to pivot the levers 112, 113 as shown in Fig. 12, retracting the
gate 69 and lifting rolls 74 through a cut-out 62a in the compiler tray to nip
5 the set against ccntinuously driven rolls 73 and drive the set out of the
compiler tray.
The rolls 73 and 7~ each comprise a spaced pair of grooved rolls with
O ring inserts. The idlers 74 are spaced slightly further apart than the
driven rolls 73.
Stapled sets are transported to the catch tray 100 around transport
roll 76 which is 70mm wide and 135mm in diameter. It has a rigid hub of a
thermoplastic resin material, suitably a modiEied polyphenylene oxide such
as Noryl, with a high friction polyurethane coating. Suitably the surface of
roll 76 has a hardness of 60+ 5 IRHD. Transport of the sets around sun roll
15 76 is aided by the compliant rolls 77, 78, 79 and the guides 80, 81. The
planet rolls 77, 78, 79 are foam rolls 30rnm in diameter and having a 10mm
thick layer of foam over a rigid hub. The foam material is a polyurethane
ester suitably having a cell size oE 18 cells per linear centimetre. The
planet rolls 77, 789 79 are driven at a slightly greater speed (about 10% or
20 more faster) than the sun roll 76 to compensate for the difference in speed
between the inner and outer surfaces of a set being transported. In one
embodiment in which the rolls have the dimensions above the sun roll 76 is
driven at a surface speed of 307mm/sec and the planet rolls 77, 789 79 are
respec~ively driven at surface speeds of 353mm/sec (15%)7 402mm/sec (31%)
25 and 335mm/sec (9%), the percentages in parenthesis indicating the amount
by which the speed of the sun roll is exceeded. The guide 81 can be hinged
down for jam access.
With the diverter solenoid 91 not energised, the diverter 64 is kept
raised by a compression spring around the solenoid plunger and sheets are
30 directed along the path 61 directly to the eject roll 76 and the catch tray
lOOo
The transport roll 76, like the nip rolls 67, 68, accelerates copies from
~he input rolls 65 to minimise set delivery time.
The offsetting catch tray 100 (Figure ll~) provides physical and v;sual
35 distinction between c~nsecutive sets and this is achieved by reciprocating
the tray through 35mm. The tray is driven by a separate D~ motor/gearbox
through a cylindrical cam 121 and follower l~la. The tray slopes upwardly
at a relatively steep angle and has an upstanding rear registration edge 126.
The tray is slideably mounted on stub shaEts 122 carried on the finisher
cover by means of brackets 123. Reaction studs 124 on the tray edge 126
5 ride on PT~E strips fixed to the outside of the cover. The catch tray is
activated by a sensor switch 127 (~ig. 1~) in the lower part of the set
transport.
A spring loaded rib 1~-2" wide extends downwardly along the tray to
maintain uniform drop height into the tray as the sheets build up. Mylar
10 control strips (not shown) hang from the cover above the tray to help guide
paper onto the tray.
The finisher drives are shown in Figures 3 and 15. A spur gear 131
takes the drive from the processor and apart from the roll 65b which is
driven directly from the spur gear 131 all driven rollers and the paddle
wheel are driven via toothed belts 132, 133 and spur gears 134, 135. The
latter are all arranged at the back of the finisher behind the rear frame 142
as shown in Figure 3. Front and rear frames 141, 142 moulded in plastic
support all finisher components. The two frames are separated structurally
by two steel tie bars, the lower plate 63b of upper transport guide 63 and
the compiler tray (sheet steel).
The finisher and its covers are moun ted separately. As shown in
Figures 2 and 3, downwardly facing ~I-mountings of the frames 1~1, 142 sit
on docking studs 143, 144 projecting from the processor frame and the
assembly is held in position by gravity. The cover is held in place by four
latch mechanisms, two front and two rear, which locate on docking studs
fixed to the processor framesL The rear latches are secured by locking
screws.
In operation sheets are either delivered to the compiler tray 62 along
the upper path 63 or fed directy to the offsetting catcil tray 100 along the
path 61. In the latter case the sheets may be stacked in offset sets by
intermittently side-shifting the tray 100 under the control of the machine
logic. Sheets delivered to the compiler tray 6~ are reverse registered by
gravity and the paddle wheel 71 against registration stops 69, 70. When all
the sheets in a set have been received in the tray 62, the machine logic
activates the motor 107 to cause the stapler 72 to insert a staple in ~he set
and then activates the solenoid 11~ to cause the gate 69 ~o retract and the
eject rolls 73, i4 to engage the set to drive the set out of the tray to the
direction reversing transport formed by the transport roll 76 and its
associated planet rolls and guides. The transport conveys the set into the
offsetting catch tray 100 where successive sets are stacked for collection by
5 an operator. The catch tray may be offset between sets.
The compiler tray will not accept more than 25 sheets. If the finisher
is in binding mode and a sensor (not shown) in the path 63 has counted 25
sheets, it will direct the twenty-sixth and subsequent sheets directly to the
catch tray 100 and also eject the stack of sheets in the tray 62 into the tray
10 100 without binding thern.
Although specific embodiments have been described, it will be
understood that various modifications may be made without departing from
the scope of the invention as defined in the appended claims. For example,
while a paddle wheel registration device is described and illustrated any
15 suitable form of sheet registration device may be employedO
