Sorting apparatus

A sorting apparatus in which a sheet loading station is arranged to advance sheets into individual sheet receiving members of one of at least two groups of sheet receiving members. The other group of sheet receiving members is positioned at one of two sheet unloading stations. After loading and unloading sheets from the respective groups of sheet receiving members, the loaded group of sheet receiving members moves to the other sheet unloading station as the unloaded group of sheet receiving members returns to the sheet loading station.

This invention relates generally to a sorting apparatus coupled to a 
printing machine, and more particularly concerns an improved system for 
collecting and sorting sheets into collated sets. 
A reproducing machine, such as an electrophotographic printing machine, 
includes a photoconductive member which is charged to a substantially 
uniform potential so as to sensitize the surface thereof. The charged 
portion of the photoconductive member is exposed to a light image of an 
original document being reproduced. Exposure of the charged 
photoconductive member selectively dissipates the charge thereon in the 
irradiated areas. This records an electrostatic latent image on the 
photoconductive member corresponding to the informational areas contained 
within the original document being reproduced. After the electrostatic 
latent image is recorded on the photoconductive member, the latent image 
is developed by bringing the developer mix into contact therewith. 
Generally, the developer mix comprises carrier granules having toner 
particles adhering triboelectrically thereto. The toner particles are 
attracted from the carrier granules to the latent image forming a toner 
powder image on the photoconductive member. The toner powder image is then 
transferred from the photoconductive member to a copy sheet. Finally, the 
copy sheet is heated to permanently affix the toner particles thereto in 
image configuration. This general approach was disclosed by Carlson in 
U.S. Pat. No. 2,297,691, and has been further amplified and described by 
many related patents in the art. 
Frequently, it is highly desirable to reproduce a plurality of copies of 
the same original document, or if several original documents are being 
reproduced, a plurality of collated sets of copies. This may be achieved 
by the utilization of a sorting apparatus. 
In the past, sorting systems included large and bulky bin modules with a 
multitude of trays arranged for movement relative to the sheet path for 
increased storage. One typical sorter employs tray members which are 
spaced apart and extend in a linear row. Another type of sorting apparatus 
has trays extending radially outwardly from the axis of rotation. Copy 
sheets may be collected in the bins of the sorter in a number of ways. The 
most common technique is to utilize the sheet transport to advance the 
copy sheets past the bin openings and deflection fingers to guide the 
sheets from the transport into the respective bin. Alternatively, the 
deflection fingers could move from bin to bin so as to deflect the copy 
sheets into the selected bin. Still yet another approach is to move the 
bins past the sheet ejecting portion of the transport. In this manner, the 
bins of the sorting apparatus collected the various sheets forwarded 
thereto. However, sorting systems of this type frequently had limitations 
in the number of copy sheets that could be collected or their size was 
extremely large and did not readily lend itself to compact printing 
machines. 
Various types of sorters have hereinbefore been developed for collecting 
sheets. The following prior art appears to be relevant: 
______________________________________ 
U.S. Pat. No.: 3,273,882 
Patentee: Pearson 
Issued: September 20, 1966 
U.S. Pat. No.: 3,395,913 
Patentee: Del Vecchio 
Issued: August 6, 1968 
U.S. Pat. No.: 3,516,654 
Patentee: Mestre 
Issued: June 23, 1970 
U.S. Pat. No.: 3,561,753 
Patentee: Snellman 
Issued: February 9, 1971 
U.S. Pat. No.: 3,740,050 
Patentee: Jacobs 
Issued: June 19, 1973 
U.S. Pat. No.: 3,788,640 
Patentee: Stemmle 
Issued: January 29, 1974 
U.S. Pat. No.: 3,848,867 
Patentee: Johnson 
Issued: November 19, 1974 
U.S. Pat. No.: 3,995,748 
Patentee: Looney 
Issued: December 7, 1976 
______________________________________ 
The pertinent portions of the foregoing prior art may be briefly summarized 
as follows: 
Pearson discloses a sorter having a plurality of stationary shelves. Tapes 
advance the sheets past the shelves. A column of deflecting fingers are 
disposed in front of the shelves. The fingers are sequentially triggered 
to deflect successive sheets into the respective shelves. 
Del Vecchio describes a sorter in which sheets are advanced by rollers to a 
diverter comprising a gate. A cam actuates the appropriate gate to guide 
the sheets into the selected catch tray. 
Mestre discloses a sorter having a plurality of pockets and a ramp for 
guiding the sheets into the pockets. The delivery end of the ramp is 
indexed to successive pockets. After the first sheet of pockets has had 
sheets delivered thereto, a second stack of pockets is moved into the 
sheet delivery position and the ramp returned to its initial position. 
Snellman describes a sorter having a plurality of stationary bins. A vacuum 
conveyor transports the sheets past the bins. A deflector also travels 
past the bins. The control system positions the deflector at the selected 
bin and the deflector strips the sheet from the transport and guides it 
into the bin. 
Jacobs describes a sorter employing a plurality of magazines having fingers 
for guiding the sheets into the respective magazine. 
Stemmle discloses a sorter employing a plurality of trays for receiving 
sheets at a sheet receiving zone. The trays are supported by elongated 
cams. Rotation of the cams moves the trays past the sheet receiving zone 
to receive sheets therein. 
Johnson describes a sorter in which a sheet advances along a path past the 
entrance to various stations. The sheets are deflected out of the path 
into a station by a movable deflector that traverses vertically past the 
stations. 
Looney discloses a sorter having two sets of vertical bins of trays. The 
bins move vertically so as to be successively aligned with the inlet and 
discharge stations. After one set of bins has been filled with copy 
sheets, the sorter rotates positioning the unfilled set of bins on the 
inlet side and the filled set of bins at the discharge side. 
It is a primary object of the present invention to improve the collecting 
and distributing of sheets by employing a compact apparatus having 
limitless sorting capabilities. 
Briefly stated, and in accordance with with the present invention, there is 
provided an apparatus for sorting sheets including at least two groups of 
sheet receiving members. Each group of receiving members comprises a 
series of individual sheet receiving members arranged to receive and 
discharge sheets therefrom. A sheet loading station is arranged to advance 
sheets into the individual sheet receiving members of the two groups of 
sheet receiving members. One of the sheet unloading stations is arranged 
to have one of the two groups of sheet receiving members positioned 
thereat for removing sheets therefrom. The other of the sheet unloading 
stations is arranged to have the other of the two groups of sheet 
receiving members positioned thereat for removing sheets therefrom. Moving 
means is coupled to the two groups of sheet receiving members. In this 
manner, one of the two groups of sheet receiving members moves to one of 
the two sheet unloading stations with the other group of sheet receiving 
members being moved to the sheet loading station so as to bring individual 
sheet receiving members into position for receiving sheets thereat. After 
sheets have been loaded and unloaded from the respective group of sheet 
receiving members, the loaded group of sheet receiving members moves to 
the other sheet unloading station with the unloaded group of sheet 
receiving members being moved to the sheet loading station. This enables 
each of the two groups of sheet receiving members to have sheets loaded 
and unloaded from the individual sheet receiving members thereof.

While the present invention will hereinafter be described in connection 
with a preferred embodiment thereof, it will be understood that it is not 
intended to limit the invention to that embodiment. On the contrary, it is 
intended to cover all alternatives, modifications and equivalents as may 
be included within the spirit and scope of the invention as defined by the 
appended claims. 
For a general understanding of the illustrative reproduction system 
including a copying machine coupled to a sorting apparatus having the 
features of the present invention incorporated therein, reference is had 
to the drawings. In the drawings, like reference numerals have been used 
throughout to designate identical elements. Although the sorting apparatus 
is particularly well adapted for use with a copying machine, it will 
become evident from the following discussion that it is equally well 
suited for use with a wide variety of printing machines and is not 
necessarily limited in its application to the particular embodiment shown 
herein. 
As illustrated in FIG. 1, the reproduction system, indicated generally by 
the reference numeral 10, includes a copying machine, preferably an 
electrophotographic printing machine, designated generally by the 
reference numeral 12, and a sorting apparatus, indicated generally by the 
reference numeral 14. Electrophotographic printing machine 12 is capable 
of producing simplex or duplex copies at the option of the machine 
operator. Printing machine 12 has a platen 16 for receiving documents to 
be reproduced and a control panel 18 for selecting different modes of 
operation such as simplex and duplex copying and the number of copies 
required to be reproduced. In accordance with the invention, the 
electrophotographic printing machine 12 is coupled to sorting apparatus 
14. Sorting apparatus 14 has two groups of sheet receiving members or 
trays. In operation, one group of trays, designated generally by the 
reference numeral 20, is in the sheet loading position while the other 
group of trays, designated generally by the reference numeral 22, is in 
the sheet unloading position. Preferably, each group of trays comprises 
ten trays. After the first group of trays 22 has received copy sheets, the 
next group of trays 20 is moved from the sheet unloading station to the 
sheet loading station. As the sheets are loaded into the second group of 
trays 20, sheets are unloaded from the first group of trays 22. The 
foregoing is shown more clearly in FIG. 2. 
Referring now to FIG. 2, an operator is shown unloading sets of collated 
copies from the first group of trays 22. This group of trays 22 has 
advanced to the sheet unloading station. Simultaneously therewith, the 
second group of trays 20 has advanced to the sheet loading position and 
copies are being advanced to the respective trays thereof. In unloading 
the collated sets of copies from the first group of trays 22, the operator 
removes the collated sets from the front of the copy machine. 
Contrariwise, the sheets are loaded into the second group of trays 20 from 
the side thereof. 
Referring now to FIG. 3, there is shown schematically the structure of 
electrophotographic printing machine 12. Inasmuch as the art of 
electrophotographic printing is well known, the various processing 
stations employed in the printing machine are shown schematically and 
their operation briefly described with reference thereto. 
As shown in FIG. 3, electrophotographic printing machine 12 includes a drum 
24 having the outer periphery thereof coated with a suitable 
photoconductive material. Preferably, drum 24 is made from a conductive 
substrate, such as aluminum, having the photoconductive material, e.g. a 
selenium alloy, deposited thereon. Drum 24 rotates in the direction of 
arrow 26 to pass through the various processing stations disposed 
thereabout. 
Initially, drum 10 moves a portion of the photoconductive surface through 
charging station A. At charging station A, a corona generating device, 
indicated generally by the reference numeral 28, charges the 
photoconductive surface of drum 24 to a relatively high, substantially 
uniform potential. A suitable corona generating device is described in 
U.S. Pat. No. 2,836,725 issued to Vyverberg in 1958. 
Thereafter, the charged portion of the photoconductive surface of drum 24 
is advanced through exposure station B. At exposure station B, an original 
document is positioned facedown on transparent platen 16. The original 
document is scanned by a moving optical system so as to produce a flowing 
light image thereof. The optical system includes an elongated horizontally 
extending lamp 30 and a movable lens 32. The lamp and lens move in 
coordination with one another across platen 16 to focus successive bands 
of illumination reflected from the original document onto the moving 
photoconductive surface of drum 24 in synchronism therewith. The optical 
light path is folded by means of a pair of image mirrors 34 and 36 
interposed between the lens and photoconductive surface of drum 24. Under 
the influence of the flowing light image, the uniformly charged 
photoconductive surface is selectively discharged in the non-image area to 
record an electrostatic latent image on drum 24. 
Next, drum 10 advances the electrostatic latent image recorded on the 
photoconductive surface to development station C. Development station C 
includes a developer housing 38 having a supply of developer material 
therein. Preferably, the developer material comprises carrier granules 
having toner particles adhering triboelectrically thereto. A bucket 
conveyor 40 advances the developer material from the bottom of developer 
housing 38 to the top thereof. The material is then cascaded downwardly 
into the active development zone. As the developer material flows 
downwardly over the upwardly moving photoconductive surface of drum 24, 
the electrostatic latent image attracts the toner particles from the 
developer mix. This forms a toner powder image on drum 24 corresponding to 
the informational areas of the original document being reproduced. 
Drum 24 then transports the toner powder image developed on the 
photoconductive surface to transfer station D. At transfer station D, a 
sheet of support material is positioned in contact with the toner powder 
image deposited on the photoconductive surface of drum 24. The backside of 
the sheet of support material is sprayed with an ion discharge from a 
transfer corona generating device 42. This induces a charge on the sheet 
of support material having a polarity and magnitude sufficient to attract 
the toner powder image from the photoconductive surface of drum 24 to the 
sheet of support material. 
Invariably, after the sheet of support material is separated from the 
photoconductive surface of drum 24, some residual particles remain 
adhering thereto. These residual particles are removed from drum 24 at 
cleaning station E. Preferably, cleaning station E includes a cleaning 
corona generating device 44 adapted to neutralize the electrostatic charge 
tending to hold the residual toner particles on the photoconductive 
surface of drum 24. The neutralized toner particles are then mechanically 
cleaned from the photoconductive surface by means of a brush or blade and 
the toner particles collected within housing 46. 
After the sheet of support material has been removed from the 
photoconductive surface, a transport 48 advances the sheet of support 
material, with the toner powder image thereon, to fusing station F. Fusing 
station F includes a fuser assembly indicated generally by the reference 
numeral 50, having a heated fuser roller 52 and a back-up roller 54. Fuser 
roll 52 and back-up roll 54 coact so as to support the advancing sheet of 
support material in pressure driving contact therebetween. The heated 
surface of fuser roller 52 contacts the toner powder image on the surface 
of the sheet of support material. The pressure and heat permanently bond 
the toner particles to the sheet of support material in image 
configuration. 
After leaving fuser 50, the sheet of support material with the toner powder 
image permanently affixed thereto advances along curvalinear sheet guides, 
indicated generally by the reference numeral 56, which have a plurality of 
spaced rollers for advancing the sheet therealong. Guide 58 of sheet 
guides 56 is movable to advance the sheet of support material to conveyor 
60 or to upper sheet supply tray 62. Tray 62 is arranged to recirculate 
the sheet of support material for duplex copying. Conveyor 60 advances the 
sheet of support material to sorting apparatus 14. 
It is believed that the foregoing description is sufficient for purposes of 
the present invention to illustrate the general operation of an 
electrophotographic printing machine coupled to the sorting apparatus of 
the present invention. 
Sorting apparatus 14 comprises a horizontal vacuum transport assembly which 
receives copy sheets from conveyor 60 and advances them to a first group 
of sheet receiving members or trays 20, or a second group of sheet 
receiving members or trays 22. A drive system moves each group of tray 
assemblies vertically intermittently for receiving copy sheets along the 
transport path. Each group of trays includes approximately 10 trays. This 
facilitates multiple bin loading and unloading. Each tray includes a tray 
portion 64 inclined at approximately 20.degree. to the horizontal, and an 
end portion 66 which is substantially perpendicular to tray portion 64 and 
then extends in a horizontal directon at tail portion 68. Tray portion 64 
and tail portion 68 are mounted on cam followers 70 and 72, respectively, 
which engage the spiral slot formed in the elongated surface of cam 
members, indicated generally by the reference numeral 74. Each tray has 
three cam followers riding in the spiral grooves of three cam members. By 
this arrangement, a three point suspension is provided for the tray 
assemblies. Each of the cam members 74 is divided into three independently 
rotatable portions 76, 78, and 80. Portion 76 may include a plurality of 
low pitch surfaces 82 while portion 78 includes one high pitched surface 
84 as well as low pitch surfaces 82. High pitch surface 84 is located 
adjacent the sheet loading zone or station so as to open the spacing 
between trays facilitating the loading of sheets therein. After the sheet 
is received in the tray assembly, the tray assembly is then closed to the 
normal gap. 
Referring now to FIG. 5, the drive mechanism for moving the tray assemblies 
vertically will be described. The drive mechanism includes a drive motor 
86 which drives six timing belts, one for each portion of cam member 74. 
Belts 88, 90, and 92, respectively, are entrained about pulleys 94, 96, 
and 98. Pulley 94 is connected to shaft 100. Pulley 96 is connected to 
shaft 102 and pulley 98 is connected to shaft 104. Portion 80 of each cam 
member 74 is hollow permitting shafts 100, 102, and 104 to pass 
therethrough. Shafts 100, 102, and 104 are pinned to the respective second 
portions 78 of cam members 74. Thus, rotation of motor 86 drives belts 88, 
90, and 92 which, in turn, cause shafts 100, 102 and 104 to rotate so as 
to rotate the respective middle portions 78 of cam members 74. Clutch 106 
couples motor 86 to belts 108, 110, and 112. Belt 108 is entrained about 
pulley 114 on first portion 80 of cam member 74. Belt member 112 is 
entrained about pulley 116 on first portion 80 of cam member 74. Belt 110 
is entrained about pulley 118 secured to portion 80 of cam member 74. 
Gears 119, 120, and 122 are mounted on the respective portions 80 of cam 
members 74. Gear 119 meshes with gear 124 on shaft 126. Shaft 126 has a 
gear 128 on the end thereof opposed from gear 124. Gear 128 meshes with 
the gear 130 on portion 76 of cam member 74. In this manner, energization 
of clutch 106 couples motor 86 to belt 108. Belt 108 rotates portion 80 of 
cam member 74 and gear 119 thereon. Gear 119 rotates gear 124 which, in 
turn, drives shaft 126 and gear 128. Rotation of gear 128 drives gear 130 
and rotates portion 76 of cam member 74. Thus, it is seen that portions 76 
and 80 of cam member 74 rotates simultaneously with energization of clutch 
106. Gear 122 meshes with gear 134 on shaft 136. Shaft 136 has a gear 138 
on the end thereof opposed from gear 132. Gear 138 meshes with gear 140 on 
portion 76 of cam member 74. Thus, energization of clutch 106 couples 
drive motor 86 to belt 110. Belt 110 rotates portion 80 of cam member 74. 
As portion 80 rotates, gear 122 rotates therewith driving gear 134 and 
shaft 136. This, in turn, drives gear 138 which causes gear 140 to rotate. 
As gear 140 rotates, portion 76 of cam member 74 rotates therewith. Hence, 
actuation of clutch 106 causes drive motor 86 to rotate both portions 76 
and 80 of cam member 74 simultaneously. Similarly, belt 112 rotates 
portion 80 of cam member 74. Gear 120 on portion 80 meshes with gear 142 
on shaft 144. Shaft 144 has a gear 146 on the end thereof opposed from 
gear 142. Gear 146 meshes with gear 148 on portion 76 of cam member 74. 
Hence, rotation of gear 146 drives gear 148 which, in turn, drives portion 
76 of cam member 74. It is, therefore, apparent that energization of 
clutch 106 also couples motor 86 to belt 112 which drives portion 80 and 
76 of cam member 74 simultaneously. 
Referring now to FIGS. 6(a) through 6(d), there is shown the manner of 
operation of sorting apparatus 14. As depicted in FIG. 6(a), the copy 
sheet advances in the direction of arrow 150. With regard to FIG. 6(a), 
clutch 106 is de-energized and portions 76 and 80 of cam members 74 are 
non-rotating. Thus, the first group of trays 20 remains stationary. 
However, portion 78 of cam member 74 is rotating. This drives the second 
group of trays 22 in an upwardly direction, as indicated by arrow 152. As 
each tray of group 22 passes the sheet path, indicated by arrow 150, a 
sheet is loaded therein. Thus, it is seen that the first group of trays 22 
moves in an upwardly direction in the loading station to receive copy 
sheets therein. After the last tray has received a copy sheet, control 
logic reverses the direction of motor 86 and clutch 106 is energized. 
As shown in FIG. 6(b), this drives tray groups 20 and 22 in a downwardly 
direction as indicated by arrow 154. When the first tray of group 20 
passes the sheet receiving position, as indicated by arrow 150, the 
machine logic once again reverses the direction of rotation of motor 86 
and de-energizes the clutch 106. At this time, the groups of trays are 
positioned as shown in FIG. 6(c). 
Turning now to FIG. 6(c), only portion 78 will rotate driving the first 
group of trays 20 in the direction of arrow 156 while the second group of 
trays 22 having the copy sheets therein remains stationary. This permits 
the machine operator to remove the copy sheets from the second group of 
trays 22 as copy sheets are being loaded into the first group of trays 20. 
Turning now to FIG. 6(d), group 20 is depicted with the last tray thereof 
having received a copy sheet. At this time, the machine logic actuates 
clutch 106 and portions 76, 78, and 80 of cam member 74 rotate driving 
both tray groups 20 and 22 in the direction of arrow 158. The first group 
of trays 20 return to the unloading position, as shown in FIG. 6(a), and 
the second group of trays 22 moves to the loading position. It is thus 
seen that each group of trays has its own dedicated unloading station 
while using a common sheet loading station. Moreover, sheets are unloaded 
from one group of trays as they are being loaded into the other group of 
trays. In this manner, the sorting apparatus is limitless in capacity and 
operates in a rapid and efficient manner. 
In recapitulation, it is evident that the sorting apparatus of the present 
invention comprises two groups of trays. One group of trays is receiving 
sheets at the common loading station with the other group of trays having 
sheets unloaded therefrom at a dedicated unloading station. After loading 
and unloading the sheets in the respective groups of trays, the process is 
reversed. Thus, the sorting apparatus of the present invention is 
limitless in capacity so as to readily enable an operator to perform an 
additional operation, i.e. stapling or stitching the collated sets of 
copies, simultaneously with new sets of copies being loaded into the 
varous trays of the sorting apparatus. 
It is, therefore, evident that there has been provided in accordance with 
the present invention, an apparatus for sorting sheets that fully 
satisfies the objects, aims, and advantages hereinbefore set forth. While 
this invention has been described in conjunction with a specific 
embodiment thereof, it is evident that many alternatives, modifications, 
and variations will be apparent to those skilled in the art. Accordingly, 
it is intended to embrace all such alternatives, modifications, and 
variations as fall within the spirit and broad scope of the appended 
claims.