CA1111099A - Pick-off device for electrostatic copier - Google Patents
Pick-off device for electrostatic copierInfo
- Publication number
- CA1111099A CA1111099A CA315,799A CA315799A CA1111099A CA 1111099 A CA1111099 A CA 1111099A CA 315799 A CA315799 A CA 315799A CA 1111099 A CA1111099 A CA 1111099A
- Authority
- CA
- Canada
- Prior art keywords
- blade
- sheet
- clutch element
- finger
- elements
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/65—Apparatus which relate to the handling of copy material
- G03G15/6532—Removing a copy sheet form a xerographic drum, band or plate
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
- B65H29/00—Delivering or advancing articles from machines; Advancing articles to or into piles
- B65H29/54—Article strippers, e.g. for stripping from advancing elements
- B65H29/56—Article strippers, e.g. for stripping from advancing elements for stripping from elements or machines
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Delivering By Means Of Belts And Rollers (AREA)
- Paper Feeding For Electrophotography (AREA)
Abstract
Title of the Invention IMPROVED PICK-OFF DEVICE
FOR ELECTROSTATIC COPIER
Abstract of the Disclosure An improved pick-off device for a copying machine of the type in which the developed image is transferred from the surface of a photoconductor to a sheet of copy paper in which a thin semi-rigid blade having a knife edge at a transversely tapered end thereof is releasably secured to a resiliently restrained element of a clutch assembly mounted at a position at which the knife edge of the blade is re-siliently biased into engagement with the photoconductor at a location in the path of the leading edge of a sheet to which an image has been transferred to guide the sheet into a narrow space between the normally stationary clutch element and a continuously driven clutch element. In response to the entry of the sheet into the narrow space the two clutch elements are coupled to cause the restrained element to move with the continuously driven element against the action of the restraining means to carry the sheet away from the photo-conductor surface. After a predetermined concomitant rotation of the clutch elements as the leading edge of the copy sheet enters the nip between an upper delivery roller and a lower delivery roller which moves with the continuously driven clutch element, the normally restrained clutch element is advanced relatively to the continuously driven clutch element to release the sheet and to restore the knife edge precisely to its initial position.
FOR ELECTROSTATIC COPIER
Abstract of the Disclosure An improved pick-off device for a copying machine of the type in which the developed image is transferred from the surface of a photoconductor to a sheet of copy paper in which a thin semi-rigid blade having a knife edge at a transversely tapered end thereof is releasably secured to a resiliently restrained element of a clutch assembly mounted at a position at which the knife edge of the blade is re-siliently biased into engagement with the photoconductor at a location in the path of the leading edge of a sheet to which an image has been transferred to guide the sheet into a narrow space between the normally stationary clutch element and a continuously driven clutch element. In response to the entry of the sheet into the narrow space the two clutch elements are coupled to cause the restrained element to move with the continuously driven element against the action of the restraining means to carry the sheet away from the photo-conductor surface. After a predetermined concomitant rotation of the clutch elements as the leading edge of the copy sheet enters the nip between an upper delivery roller and a lower delivery roller which moves with the continuously driven clutch element, the normally restrained clutch element is advanced relatively to the continuously driven clutch element to release the sheet and to restore the knife edge precisely to its initial position.
Description
sackqround of the Invention These are known in the prior art plain paper electrostatic copying machines in which a drum carries a surface coating of photoconductive material, such for example as selenium. In operation of such a machine the surface of the drum is moved successively past the charging station at which a corona applies a uniform electrostatic charge over the surface of the drum and then to an exposure station at which the chargedsurface is exposed to an image of the original to be copied. At this station, the surface of the drum over relatively light areas of the image to be copied loses its charge while retaining its charge in relatively darker areas of the original, thus to produce a latent electrostatic image of the original to be copied.
Following the exposure station, the surface is carried through a developer station at which the latent image is subjected to the action of the developer including toner particles which adhere to the charged areas of the image, thus to develop the image. As the surface carrying the developed image leaves the developer station, it moves past a point at : .
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which a lenqth of copy material, such as ordinary paper to which the image is to he transferred is fed to the drum 80 as to be carried along with the drum beneath a transfer corona. This transfer corona causes the particles of toner to migrate from the surface oE the photoconductor to the surface of the copy sheet.
After the image has thus been transferred to the length of copy material, it is necessary to remove the sheet from the surface of the photoconductor which may, for ex-ample, be on a drum. In one particular arrangement employedto pick of a copy sheet carrying a developed image ~n a machine of the type described above, a stationary flexible band conforming to the coniguration of the drum over a portion of the circumference thereof from the location at lS which copy material is fed to the drum to a location beyond -the transfer corona is mounted at the edge of the drum, so that a narrow strip of copy material extending along a side thereof moves over the stationary flexible band as the length of copy material moves under the transfer corona. At ~he point at which the copy material is to be removed from the surface of the drum, a strucX up portion of the flexible ; strip ~oves a leading corner of the length of copy material away from the drum and into the nip between a turn roll and a rubber belt, a portion of the length oP which extend3 ' ', ' ~.. ~ '. ':i . ' ~_ 3 ij ~
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' around and int~ contact with the surface of the turn roll.
The turn roll is driven in cooperation with the belt to carry the developed sheet away from the photoconductive drum toward conveyor rollers which deliver the sheet to the user of the machine. This pick-off arrangement is illus-.~ ~
trated in a~ is more fully described in Ariyama Patent 3,936,045, for "Sheet Stripping Device for Copying Apparatus".
After the photoconductive surface leaves thepick-off station described hereinabove, it next mo.ves through a cleaning station at which a sponge roller in engagement with the surface of the drum is driven in such a direction that the engaging surface portions of the roller and the drum move in opposite directions. This sponge roller normally -: is wet with developer to facilitate the cleaning action and to prevent scratching of the drum surface by toner particles which remain on the roller t~hen the developer dries~
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While the machine described above functions satis-factorily in most instances, it incorporates a number of serious disadvantages. First, it will readily be apparent from the description of the pick-off system described here-'~ inabove, that the copy sheet can have no image transferred thereto over t'he space along the edge thereof which rides over the flexi'ble band extending through the transfer station.
Thus, where the original carries information or printlng in ' ' ' .
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this area, it will not appear on the copy. Attempts to obviate this problem by minor modifications for directing the corner of the sheet into the nip between the turn roller and the belt without the use of a strip extending through the transfer station have not proved successful since any developed image in the strip which formerly was blank became smeared or dirtied, Landa Canadian Application Serial No. 311,447, filed September 18, 1978, shows a pick-off system which overcomes the defects of the pick-off system described hereinabove. More specifically, Landa discloses a clutch assembly including a first continuously rotating element and a second element including a finger disposed in closely spaced relationship to the outer surface of the first member and restrained against rotation with the first element by a follower resiliently urged into engagement with a cam on the first member. The clutch assembly is mounted with the mouth of the narrow space closely adjacent to the surface of the photoconductor at a location .
beyond the transfer station of the machine. Means is provided for guiding the leading edge of the sheet into the mouth of the opening so that the clutch elements move together against the action of the cam follower biasing means to carry the leading edge of the sheet into the nip between a pair of `~i : ' sd~ ~i 5 . ' ; ' ' ' . , -'. . . : , ~ .
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:: ' delivery rolls. At that point the cam and follower under the action of the follower biasin,g mean~3 coact to release the elutch and to restore the second clutch element to its initial position. TXe Landa application suggests a number of specific devices for guiding the leading edge of a sheet of paper from the ~urface of the photoconductor into the mouth of the space between the two clutch elements. First, the application dis-closes a shoe pivoted on the machine frame and resting on the photoconductor susface at a location at which it intercepts the leading edge of the sheet. Secondly, the application discloses mean~ for forming a crimp in the sheet so that the leading edge automatically enters into the mouth. A third device suggested in the application is an air jet directed toward the surface so as to lift the leading edge off the surface and into the mouth of the clutch space. ~hile it is possible to direct the leading edge of the sheet into the clutch mouth by any of the means set forth in the Landa ap-; plication none of these means are as certain in operation as 19 desirable. That i9, while any of the means will operate for a certain period of time without failure, the occa3ionson which they fail to operate, requlting in paper jams, are too frequent.
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Summarv of the Invention One object of our invention is to provide an : _ _ ':; :
improved pick-off for a copying machine which overcomes the defects of pick-o-ff systems of the prior art.
- The above object is met by the present invention which broadly provides a copying machine of the image transfer type in which an image developed on a surface is transferred to a sheet of copy material whic:h moves with the surface through a transfer stati~n to a pick-off station, pick-off apparatus including a first clutch element, means for driving the first clutch element, a second clutch element, means mount-ing the second clutch element for movement relative to the first clutch element with a narrow space between the elements, ~: an opening leading into the narrow space, means positioning the clutch elements with the opening at a location adjacent to the surface, means including a blade carried by the second ` clutch element for movement therewith, the blade extending from the opening to a location at which it engages the moving ` surface to intercept the leading edge of a copy sheet moving with the surface to strip a portion of the sheet away from the ; surface and to direct the portion into the space between the elements, the relationship between the thickness of the sheet and the space between the elements being such that entry of the sheet into the space clutches the elements ta each other for movement as a unit, and means responsive to a predetermined : movement of the elements as a unit for releasing the portion of ~` a copy sheet, Other and further features of my invention will appear in the following description.
:; BRIEF DESCRIPTION OF THE DRAWINGS
:. - - -- - --v_ In the accompanying drawings which form part of the ::
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instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts of the various views:
FIGURE 1 is a simplified schematic view of the drive .~' .
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-system of an electrostatic copyiny machine incorporating ourimproved pick-off device with parts of the machine removed.
FIGURE 2 lS a diagrammatic view of the copy paper handling system of the electrostatic copier illustrated in FIGURE 1.
: FIGURE 3 is a fragmentary sectional view of the copylng machine illustrated in FIGURES 1 and 2 and showing our improved picX-off device.
FIGURE 4 is a fragmentary view with parts in section illustrating our improved pick-off device for copying machines.
FIGURE 5 is a fragmentary elevation of our improved , pick-off device for copying machines.
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FIGURE 6 is a fragmentary sectional view of our improved pick-off device for copying machines~
Description of the Preferred Embodiment ; Referring now to FIGURE 1 and 2 of the drawings, ;a machine indicated generally by the reference character 10 with which our improved picX-off device is used include~ a cabinet 12, the top of which is provided with a transparent platen 14, normally covered by a cover 15 hinged to the ' ~ ' ' :, . , . : ., :
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?~ , - cabinet. The cover can be moved away from the platen to permit an original to be placed face down to the platen. A
drum 16 carrying a suitable photoconductor on the 3urface thereof is rotatably supported for movement in the cabinet 10 by any suitable means known to the art. In the schematic view in FIGURE 1, for purposes of qi~plicity, we have illus-trated gears in broken lines and have indicated sprocXet wheels in full lines. A gear 18 which rotates with the drum 16 is adapted to be driven to rotate the drum in the direction of the arrow A in FIGURE 1. Machine 10 ncludes a prime mover 20, the output shaft of which carries a sprocket wheel 22 adapted to drive a pitch chain 24 to drive a sprocket wheel 26. Chain 24 moves in the direction of the arrow adjacent to the chain so that a gear 28 mounted on the shaft of sprocket wheel 26 for rotation therewith drives gear 1~ to rotate the dru~ 16 in the direction of the arrow A.
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Further, as is known in the art, as the drum 16 rotates in the direction of the arrow A, its surface moves successively past a corona 30, which is activated to produce a uniform electrostatic charge on the surface of the drum. .' After leaving the corona 30, the surface passes by an ex-; posure station indicated by the arrow 32 at which a moving optical system scans the original which has been placed f~ce down on platen 14 so as to translate a line image of the original to the surface of the moving drum 16. Since the _g_ .
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' details of the optical system, per se, form no part of our invention, they have not been shown in the drawings.
After leaving the exposure station 32, the surface of the drum moves through a developer unit 34 at which the latent electrostatic image thereon is sub~ected to the action of a li~uid developer containing particles of toner which adhere to those areas of the drum surface which have retained their charge after exposure to the image. As the developed : latent image moves further in the direction of the arrow A, a sheet of plain paper is fed to the drum at a station in-dicated generally by the reference character 36. The paper moves with the drum past a transfer corona 38 which is ` energi~ad to cause the developed image to migrate from the UrfaCe of the drum to the underside of the paper. After transfer has thus been effected, the sheet carrying the de veloped and transferred image is to be carried away from the drum at a pick-off station indicated generally by the ref-erence character 40.
A qear 42 which meshes with the drum gear 18 pro-vides the input to the copy pick-off and delivery system.
Gear 42 i8 on a shaft which is common with a sprocket wheel 44 90 that gear 42 and sprocket wheel 44 rotate around an axis "b" which is the axis of the take-off roll to be do-- scribed moro fully hereinbelow. Sprocket wheel 44 drive~
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pitch chain 46 in the direction of the arrow adjacent to the chain in FIGURE 1. Chain 46 in turn drives a sprocket wheel 48, the shaft of which also carries a gear 50 which meshes with a gear 52 to drive gear ~2 in a counterclockwise direc-5 : tion around the axis "a" of the cleaner roll to be describedin detail hereinbelow.
Chain 46 also engages a tensioning sprocket wheel 54 and a sprocket wheel 56 mounted for rotation around the - axis "c" of the lower of a pair of take-off rolls ,to be de-scribed here~nbelow. A hold-down roller sprocket wheel 58 is engaged by chain 46 so as to be driven in counterclockwise , direction around the axis "d". Finally, the pitch chain 46 also drives a lower delivery roll sprocket wheel 60 mounted for movement around an axis "e". An idler sprocket wheel 62 completes the path of the chain back to sprocXet wheel 48.
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- The drive system for the copy paper supply assembly includes a gear 64 adapted to be driven by the drum gear la.
A sprocket wheel 66 o~ a shaft common to the gear 64 is driven around an axis "f" to drive a pitch chain 68,in the direction of the arrow adjacent to the chain in FIGURE 1. Chain 68 drives respective upper and lower paper supply roll sprocket wheels iO and 72 mounted for movement around respective ~xes g" and ~h". ~ tensioning sprocXet wheel 74 is arranged to give sufficient tonsion to the chain 68. ~11 of the gear, I
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sprocket wheel and pitch chain mechanism just described i8 located at the rear of the machine lOo As can be seen by reference to FIGURE 2, a spongy cleaner roll 76 mounted for movement around the axis "a" is S driven by gear 52 so that the surface of the cleaning roll in engagement with the drum moves in a direction opposite to the direction of movement of the drum surface.
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` A taXe-off roll 78, more fully to be described her~inafter, cooperates with a roller 80 to deliver a picXed 1 10 off sheet to the nip between a pair of intermediate conveyor rolls 82 and B4, the roll 84 of which is mounted for movement around the axis "c". After leaving the rolls 82 and 84, the -~ sheet passes between a hold-down roller 86 mounted for move-ment around the axis "d" so as to be brought into operative 15 relationship with a dryer 88. As the sheet leaves the dryer 88, it enters tha nip between delivery rolls 90 and 92, the lower roll 92 of which i9 mounted for movement around the axis "e". These rolls pass the copy to a tray 106, or the liX~.
- 20 The machine with which our improved pick-off i9 used includes two cassettes holding respective supplies 98 and 102 of paper o different 3izes. Respective paper feeding rolls 100 and 104 associated wlth the supplies 98 and 102 are mounted for movement at the axes "g" and "h". Means ~not t -12-.: shown) under the control of the operator is adapted to be actuated selectively to bring one or the other of the supplies 98 or 102 into cooperative relationship with.its as30ciated roller 100 or 104. The operative.roller delivers a sheet to - S the nip between a pair of feed rolls 94 and 96, the upper one of which i3 mounted for movement at the axis "f". Roll3 94 and 96 deliver the fed sheet to the surface of the drum 16.
The structure thus far described is that of a machine to which -~
` our improved pick-off device i9 applied.
; 10 Referring now to FIGURES 3 to 6, gear 42, which ~s disposed in a housing 108 carrièd by a side of the machine, drives a shaft 110 e~tending out of the housing 108. The clutch assembly indicated generally by the reference character 112 which forms a part of our improved pick-off, includes a driver member 114, which is keyed to the shaft 110 by a key 116. This key 116 is so arranged a3 to permit some radial ~ovement of the clutch member 114 with reference to the shaft 110 for accurate positioning relative to the shaft in a manner .~ ~ to be described hereinbelow. M~mber 114 further is adapted 7~
to receive a reduced end portion 118 of turn roller ;~, the arrangement being such that when the reduced end portion 118 i3 inserted into the member 114 roll 78 rotates with the member 114.
~ous~ing 108 carries respective outwardly extending .
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- studq 120 and 122 which receive a bracket 124 secured to the studs by any suitable means known to the art. A pin 126 carried by the bracXet 124 intermediate its ends pivotally supports an arm 128, the end of which carries a shaft 1~9 S which rotatably supports a metal roller 130 having a knurled outer surface. A spring 134 wrapped around the pin 126 bears with one end against the bracXet 124 and with the other end against the arm 128, so as to resiliently to urge the roller 130 into engagement with rubber rings 132 carried by clutch member 114.
The other clutch member 136 includes a disk-like portion on an integral axially extending hub portion 138 carried by a bushing 140 supported on the shaft 110. Ra-spective ball bearings 142 and 144, the inner rings of which are received on the hub 138 are held in spaced relationship by a spacer 146 located between the outer rings of the bearings, These bearings 142 and 144 are received in a recess 148 formed in the clutch member 114. Bearings 142 and 144 accurately space clutch member 114 in a radial direc-tion with reference to the hub 138 of the clutch m~mber 136.
As has been pointed out hereinabove, the key 116 permit~
soma radial movement o the clutch member 114 relative to the ~haft 110, thus to permit the bearings 142 and 144 to perEorm the function of accurately positioning the member 114 radially with reference to the hub 138 of the member 136.
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From the structure thus far descrioed, it will readily be apparent that shaft 110 continuously drives the member 114 owing to the connection therebetween provided by the key 116. Moreover, under the action of friction, member 136 likewise would tend to rotate w~ith the shaft 110. The clutch assembly is provided with means for normally restrain-ing member 136 against rotation with the shaft 110. Clutch ..,':
136 is formed with a cam 150 having a low point l50a followed by a rising portion 150b in the counterclockwise direction as viewed in FIGURE 6 and then a relatively sharp drop 150c.
Stud 120 rotatably supports a follower arm 154 carrying a follower 152 adapted to ~i~ against the cam 150. A spring 156 on the stud 120 normally urges the arm 154 to rotate in a clockwise direction as Yiewed in the drawings. In the - ~' inactive condition of the parts, follower 152 rests against in~
the lowll50a of the cam. In this condition the action of spring 156 on the arm 154 overcomes the frictional tendency of the clutch member 136 to rotate with clutch member 114, so that the clutch member 136 is stationary.
The disk-liXe portion of clutch member 136 i~
formed with a peripheral axially extending finger 158 which extend~for a predetermined distance around the disk-like portion of member 1360 It will be seen that finger 158 forms a narrow radial gap with member 114. The radial extent of the gap i~ accurately determined by the bearings 142 and , -.
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~ 144. In practice the spacing between the finger 158 and the ;` member 114 ~ay be of the order of two mils. We provlde a roughened surface portion 160 on the outer surPace of member 114 below the finger 115 and highly polish the inner surface 162 of the member 158. ~5 will more fully be explained here-.
inbelow, in operation of the clutch the surface 162 cooperates with the image bearing side of the copy sheet, while the surface 160 cooperates with the reverse side of the copy sheet. The space between the finger 158 and the member 114 - 10 is such that introduction of the leading edge of a sheet of common copy paper into the space between the finger and the member will clutch the finqer and the member together with sufficient force to overcome the influence of spring 156 to cause the two members to move together. Moreover, as the two members move together, follower 152 rides up the rise 150b, thus to increase the force with which the leading edge of the paper i8 gripped. As the paper is thus carried around with the two clutch elements in a clocXwise direction as viewed in the drawlngs, ultimately the sharp drop lSOc in the surface of cam 150 will arrive at the location of the , follower 152. As the follower 152 moved up the ri~e ~
the force stored in the spring 156 increases. Thus~ when the drop 150c arrives at the follower 152, thc spring 156 : - .
rapidly moves clutch member 136 and finger 158 carried thereby in a clockwlse, direction but more rapidly than the speed of rotation o f member 114, thus to release the portion : .
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of the leading edge of the copy which has been gripped by the clutch mechanism. It will readily be appreciated that the highly polished inner surface of finger 158 facilitates this releasing operation. At the time of this releasing operation, the leading edge of the paper has already moved into the nip between the knurled roller 130 and the rubber rings 132.
From this point, the copy paper is carried out of the machine by means of the delivery rolls B2 and 84. It i5 to be empha-- sized that under the action of the cam and follower, finger 158 is brought precisely back to the same location on each operation of the machine.
Our improved pi~k-off device includes a blade 164 formed of a ~uitable material which will not result in ex-, CQssiVe wear on the photoconductor. We may, for example, form the blade 164 from polytetrafluoroethylene copolymer or - ~ polyethylene terephthalate copolmcr. An opening 166 in the blade 164 receives a post or pin 168 carried by the finger 158 of the normally stationary clutch element. We secure an arcuate resilient retainer 170 to the finger 158 by means :. 20 of a rivet 172 or the like which passes through a spacer 174 between the retainer 170 and finger 158. A hole 176 in the ; retainer 170 receives an extension 178 on pin 168. It will readily be appreciated that the retainer 170 releasably hold~
the blade 16~ ln position on finger 158. ~he blade 164 can readily be removed and replaced by moving the retainer 170 .
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to the broken line position shown ln FIGURE 6.
Preferably, we form the lower part of the finger 164 as viewed in the drawings with a thickened portion 182 which obviates the danger of the leading edge of a sheet being directed toward the location at which the lower end of finger 158 as viewed in the drawings engages blade 164.
It will readily be appreciated that the occurrence of the event which i8 obviated by thickened portion 182 could easily result in a jam.
Thickened portion 182 terminates in a knife edge 180 adapted to engage the photoconductor drum surface. We provide the lower end of the blade 164 with a lateral taper 184 to minimize the line of contact between the knife edge 180 and the drum 16.
While the material of which our blade 164 is formed i~ Felatively rigid, it is also somewhat resilient.
Ir the pick-off assembly were displaced from the drum the blade 164 would assume the position shown in broken line in FIGURE 6. If the pick-off assembly is restored to its normal position adjacent to the drum, the blade 164 moves ; to the full line position shown in FIGURE 6. It will thu~
be seen that, in the operative position of the picX-off assembly the blade 164 is biased into engagement with the surface of drum 16 by virtue of the inhcrent resiliency o~
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tlle material o~ which the blade is made.
We provide the copy machine with which our pick-o~f ,; .
assembly is used with means for preventing sheets which are not picked off by -the pick-off assembly and more particularly second sheets resulting from doub:Le feeds from advancing to the cleaning roll 76 and becoming wrapped -therearound. A shoe 186 having a recess 188 is carried by a rod 190 supported on an actuator 192 connected to a sleeve 194 received by a vertically extending pin 96 on a bracket 198. When a sheet is not picked off by the pick-off assembly its leading edge enters recess 188 or engages actuator 192 to cause the actuator 192 to rotate around pivot pin 196. When this occurs, a wire 200 carried by the actuator operates a switch 202 carried by a bracket 204. This causes the machine to stop and activate a suitable indicator.
The operation of our improved pick-off device will readily be understood from the description hereinabove. So long as the drum 16 is being driven, shaft 110 is driven to drive clutch member 114. At the same time, the action of spring 156 prevents rotation of clutch member 136 with the member 114. After an image has been formed on the drum 16 - and developed, a '' , .
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sheet of copy material iq fed to the drum beneath the transfer corona 38. As the sheet moves past the tranqfer corona, the developed image migrates from the surface of the drum to the surface of the sheet in contact with the drum. As a sheet which has received the image moves out of the transfer loca-tion, its leading edge rides up the thickened portion 182 of blade 164 and is directed into the space between finger 158 and member 114. The thickened portion 182 directs the leading edge of the sheet away from the line of contact between the lower end of finger 158 and blade 164. Owing to the relation-ship of the thicXness of the sheet 168 to the space between finger 158 and member 114, as the leading edge of the sheet enters the space, the finger 158 and member 114 are clutched together to overcome the force of spring 156 and to cause lS the follower 152 to ride up the cam rise 150b. As thiq occurs, the sprlng is loaded to increase the force with which the leading edge o the paper is grasped between the finger 158 and the member 114. After a predetermined rotation of - member 114 to a location at which the leading edge of the paper has moved into the nip between roller 130 and ringq 132, the cam drop 150c has arrived at the location of follower 152. At this point the force of the loaded spring 156 move~
the member 136 and finger 158 in the same direction and at a greater ~peed than the member 114 to release the leading odgo of the sheet. As has been pointed out hereinabove, the highly polished surface 162 of finger 158 facilit~tes this , , $~
releasing action, At the and of the operation knife edge 180 returns to precisely the same position it occupied at ehe beginning.
, It addition to the foregoing, if by any chance a double feed occurs, the second sheet will be intercepted by shoe 1~6 or actuator 192, the machine will stop and the user will be informed of the malfunction.
It will be seen that we have accomplished the objects of our invention. we have provided a pick-off for a copying machine which overcomes the defects of pick-off systems of the prior art. Our pick-off device permits sub-stantially the entire area of the copy sheet to receive a transferred image. Our picX-off device is reliable in operation. Our pick-o~f arrangement incooperateS means for preventing a double fea sheet from becoming wrapped around the cleaninq roller of the machine. Our device successfully pick9 a copy sheet off the drum and delivers it to the customer without smudging any part of the formed image and without dirtying the copy. It is extremely reliable in operation.
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' It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of our claims. It I
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; understood that our invention i9 not to be limited to the speciic details shown and described.
Having thus described our invention, what we claim~ is:
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Following the exposure station, the surface is carried through a developer station at which the latent image is subjected to the action of the developer including toner particles which adhere to the charged areas of the image, thus to develop the image. As the surface carrying the developed image leaves the developer station, it moves past a point at : .
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which a lenqth of copy material, such as ordinary paper to which the image is to he transferred is fed to the drum 80 as to be carried along with the drum beneath a transfer corona. This transfer corona causes the particles of toner to migrate from the surface oE the photoconductor to the surface of the copy sheet.
After the image has thus been transferred to the length of copy material, it is necessary to remove the sheet from the surface of the photoconductor which may, for ex-ample, be on a drum. In one particular arrangement employedto pick of a copy sheet carrying a developed image ~n a machine of the type described above, a stationary flexible band conforming to the coniguration of the drum over a portion of the circumference thereof from the location at lS which copy material is fed to the drum to a location beyond -the transfer corona is mounted at the edge of the drum, so that a narrow strip of copy material extending along a side thereof moves over the stationary flexible band as the length of copy material moves under the transfer corona. At ~he point at which the copy material is to be removed from the surface of the drum, a strucX up portion of the flexible ; strip ~oves a leading corner of the length of copy material away from the drum and into the nip between a turn roll and a rubber belt, a portion of the length oP which extend3 ' ', ' ~.. ~ '. ':i . ' ~_ 3 ij ~
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' around and int~ contact with the surface of the turn roll.
The turn roll is driven in cooperation with the belt to carry the developed sheet away from the photoconductive drum toward conveyor rollers which deliver the sheet to the user of the machine. This pick-off arrangement is illus-.~ ~
trated in a~ is more fully described in Ariyama Patent 3,936,045, for "Sheet Stripping Device for Copying Apparatus".
After the photoconductive surface leaves thepick-off station described hereinabove, it next mo.ves through a cleaning station at which a sponge roller in engagement with the surface of the drum is driven in such a direction that the engaging surface portions of the roller and the drum move in opposite directions. This sponge roller normally -: is wet with developer to facilitate the cleaning action and to prevent scratching of the drum surface by toner particles which remain on the roller t~hen the developer dries~
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While the machine described above functions satis-factorily in most instances, it incorporates a number of serious disadvantages. First, it will readily be apparent from the description of the pick-off system described here-'~ inabove, that the copy sheet can have no image transferred thereto over t'he space along the edge thereof which rides over the flexi'ble band extending through the transfer station.
Thus, where the original carries information or printlng in ' ' ' .
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this area, it will not appear on the copy. Attempts to obviate this problem by minor modifications for directing the corner of the sheet into the nip between the turn roller and the belt without the use of a strip extending through the transfer station have not proved successful since any developed image in the strip which formerly was blank became smeared or dirtied, Landa Canadian Application Serial No. 311,447, filed September 18, 1978, shows a pick-off system which overcomes the defects of the pick-off system described hereinabove. More specifically, Landa discloses a clutch assembly including a first continuously rotating element and a second element including a finger disposed in closely spaced relationship to the outer surface of the first member and restrained against rotation with the first element by a follower resiliently urged into engagement with a cam on the first member. The clutch assembly is mounted with the mouth of the narrow space closely adjacent to the surface of the photoconductor at a location .
beyond the transfer station of the machine. Means is provided for guiding the leading edge of the sheet into the mouth of the opening so that the clutch elements move together against the action of the cam follower biasing means to carry the leading edge of the sheet into the nip between a pair of `~i : ' sd~ ~i 5 . ' ; ' ' ' . , -'. . . : , ~ .
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:: ' delivery rolls. At that point the cam and follower under the action of the follower biasin,g mean~3 coact to release the elutch and to restore the second clutch element to its initial position. TXe Landa application suggests a number of specific devices for guiding the leading edge of a sheet of paper from the ~urface of the photoconductor into the mouth of the space between the two clutch elements. First, the application dis-closes a shoe pivoted on the machine frame and resting on the photoconductor susface at a location at which it intercepts the leading edge of the sheet. Secondly, the application discloses mean~ for forming a crimp in the sheet so that the leading edge automatically enters into the mouth. A third device suggested in the application is an air jet directed toward the surface so as to lift the leading edge off the surface and into the mouth of the clutch space. ~hile it is possible to direct the leading edge of the sheet into the clutch mouth by any of the means set forth in the Landa ap-; plication none of these means are as certain in operation as 19 desirable. That i9, while any of the means will operate for a certain period of time without failure, the occa3ionson which they fail to operate, requlting in paper jams, are too frequent.
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Summarv of the Invention One object of our invention is to provide an : _ _ ':; :
improved pick-off for a copying machine which overcomes the defects of pick-o-ff systems of the prior art.
- The above object is met by the present invention which broadly provides a copying machine of the image transfer type in which an image developed on a surface is transferred to a sheet of copy material whic:h moves with the surface through a transfer stati~n to a pick-off station, pick-off apparatus including a first clutch element, means for driving the first clutch element, a second clutch element, means mount-ing the second clutch element for movement relative to the first clutch element with a narrow space between the elements, ~: an opening leading into the narrow space, means positioning the clutch elements with the opening at a location adjacent to the surface, means including a blade carried by the second ` clutch element for movement therewith, the blade extending from the opening to a location at which it engages the moving ` surface to intercept the leading edge of a copy sheet moving with the surface to strip a portion of the sheet away from the ; surface and to direct the portion into the space between the elements, the relationship between the thickness of the sheet and the space between the elements being such that entry of the sheet into the space clutches the elements ta each other for movement as a unit, and means responsive to a predetermined : movement of the elements as a unit for releasing the portion of ~` a copy sheet, Other and further features of my invention will appear in the following description.
:; BRIEF DESCRIPTION OF THE DRAWINGS
:. - - -- - --v_ In the accompanying drawings which form part of the ::
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instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts of the various views:
FIGURE 1 is a simplified schematic view of the drive .~' .
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-system of an electrostatic copyiny machine incorporating ourimproved pick-off device with parts of the machine removed.
FIGURE 2 lS a diagrammatic view of the copy paper handling system of the electrostatic copier illustrated in FIGURE 1.
: FIGURE 3 is a fragmentary sectional view of the copylng machine illustrated in FIGURES 1 and 2 and showing our improved picX-off device.
FIGURE 4 is a fragmentary view with parts in section illustrating our improved pick-off device for copying machines.
FIGURE 5 is a fragmentary elevation of our improved , pick-off device for copying machines.
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FIGURE 6 is a fragmentary sectional view of our improved pick-off device for copying machines~
Description of the Preferred Embodiment ; Referring now to FIGURE 1 and 2 of the drawings, ;a machine indicated generally by the reference character 10 with which our improved picX-off device is used include~ a cabinet 12, the top of which is provided with a transparent platen 14, normally covered by a cover 15 hinged to the ' ~ ' ' :, . , . : ., :
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?~ , - cabinet. The cover can be moved away from the platen to permit an original to be placed face down to the platen. A
drum 16 carrying a suitable photoconductor on the 3urface thereof is rotatably supported for movement in the cabinet 10 by any suitable means known to the art. In the schematic view in FIGURE 1, for purposes of qi~plicity, we have illus-trated gears in broken lines and have indicated sprocXet wheels in full lines. A gear 18 which rotates with the drum 16 is adapted to be driven to rotate the drum in the direction of the arrow A in FIGURE 1. Machine 10 ncludes a prime mover 20, the output shaft of which carries a sprocket wheel 22 adapted to drive a pitch chain 24 to drive a sprocket wheel 26. Chain 24 moves in the direction of the arrow adjacent to the chain so that a gear 28 mounted on the shaft of sprocket wheel 26 for rotation therewith drives gear 1~ to rotate the dru~ 16 in the direction of the arrow A.
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Further, as is known in the art, as the drum 16 rotates in the direction of the arrow A, its surface moves successively past a corona 30, which is activated to produce a uniform electrostatic charge on the surface of the drum. .' After leaving the corona 30, the surface passes by an ex-; posure station indicated by the arrow 32 at which a moving optical system scans the original which has been placed f~ce down on platen 14 so as to translate a line image of the original to the surface of the moving drum 16. Since the _g_ .
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' details of the optical system, per se, form no part of our invention, they have not been shown in the drawings.
After leaving the exposure station 32, the surface of the drum moves through a developer unit 34 at which the latent electrostatic image thereon is sub~ected to the action of a li~uid developer containing particles of toner which adhere to those areas of the drum surface which have retained their charge after exposure to the image. As the developed : latent image moves further in the direction of the arrow A, a sheet of plain paper is fed to the drum at a station in-dicated generally by the reference character 36. The paper moves with the drum past a transfer corona 38 which is ` energi~ad to cause the developed image to migrate from the UrfaCe of the drum to the underside of the paper. After transfer has thus been effected, the sheet carrying the de veloped and transferred image is to be carried away from the drum at a pick-off station indicated generally by the ref-erence character 40.
A qear 42 which meshes with the drum gear 18 pro-vides the input to the copy pick-off and delivery system.
Gear 42 i8 on a shaft which is common with a sprocket wheel 44 90 that gear 42 and sprocket wheel 44 rotate around an axis "b" which is the axis of the take-off roll to be do-- scribed moro fully hereinbelow. Sprocket wheel 44 drive~
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pitch chain 46 in the direction of the arrow adjacent to the chain in FIGURE 1. Chain 46 in turn drives a sprocket wheel 48, the shaft of which also carries a gear 50 which meshes with a gear 52 to drive gear ~2 in a counterclockwise direc-5 : tion around the axis "a" of the cleaner roll to be describedin detail hereinbelow.
Chain 46 also engages a tensioning sprocket wheel 54 and a sprocket wheel 56 mounted for rotation around the - axis "c" of the lower of a pair of take-off rolls ,to be de-scribed here~nbelow. A hold-down roller sprocket wheel 58 is engaged by chain 46 so as to be driven in counterclockwise , direction around the axis "d". Finally, the pitch chain 46 also drives a lower delivery roll sprocket wheel 60 mounted for movement around an axis "e". An idler sprocket wheel 62 completes the path of the chain back to sprocXet wheel 48.
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- The drive system for the copy paper supply assembly includes a gear 64 adapted to be driven by the drum gear la.
A sprocket wheel 66 o~ a shaft common to the gear 64 is driven around an axis "f" to drive a pitch chain 68,in the direction of the arrow adjacent to the chain in FIGURE 1. Chain 68 drives respective upper and lower paper supply roll sprocket wheels iO and 72 mounted for movement around respective ~xes g" and ~h". ~ tensioning sprocXet wheel 74 is arranged to give sufficient tonsion to the chain 68. ~11 of the gear, I
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sprocket wheel and pitch chain mechanism just described i8 located at the rear of the machine lOo As can be seen by reference to FIGURE 2, a spongy cleaner roll 76 mounted for movement around the axis "a" is S driven by gear 52 so that the surface of the cleaning roll in engagement with the drum moves in a direction opposite to the direction of movement of the drum surface.
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` A taXe-off roll 78, more fully to be described her~inafter, cooperates with a roller 80 to deliver a picXed 1 10 off sheet to the nip between a pair of intermediate conveyor rolls 82 and B4, the roll 84 of which is mounted for movement around the axis "c". After leaving the rolls 82 and 84, the -~ sheet passes between a hold-down roller 86 mounted for move-ment around the axis "d" so as to be brought into operative 15 relationship with a dryer 88. As the sheet leaves the dryer 88, it enters tha nip between delivery rolls 90 and 92, the lower roll 92 of which i9 mounted for movement around the axis "e". These rolls pass the copy to a tray 106, or the liX~.
- 20 The machine with which our improved pick-off i9 used includes two cassettes holding respective supplies 98 and 102 of paper o different 3izes. Respective paper feeding rolls 100 and 104 associated wlth the supplies 98 and 102 are mounted for movement at the axes "g" and "h". Means ~not t -12-.: shown) under the control of the operator is adapted to be actuated selectively to bring one or the other of the supplies 98 or 102 into cooperative relationship with.its as30ciated roller 100 or 104. The operative.roller delivers a sheet to - S the nip between a pair of feed rolls 94 and 96, the upper one of which i3 mounted for movement at the axis "f". Roll3 94 and 96 deliver the fed sheet to the surface of the drum 16.
The structure thus far described is that of a machine to which -~
` our improved pick-off device i9 applied.
; 10 Referring now to FIGURES 3 to 6, gear 42, which ~s disposed in a housing 108 carrièd by a side of the machine, drives a shaft 110 e~tending out of the housing 108. The clutch assembly indicated generally by the reference character 112 which forms a part of our improved pick-off, includes a driver member 114, which is keyed to the shaft 110 by a key 116. This key 116 is so arranged a3 to permit some radial ~ovement of the clutch member 114 with reference to the shaft 110 for accurate positioning relative to the shaft in a manner .~ ~ to be described hereinbelow. M~mber 114 further is adapted 7~
to receive a reduced end portion 118 of turn roller ;~, the arrangement being such that when the reduced end portion 118 i3 inserted into the member 114 roll 78 rotates with the member 114.
~ous~ing 108 carries respective outwardly extending .
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- studq 120 and 122 which receive a bracket 124 secured to the studs by any suitable means known to the art. A pin 126 carried by the bracXet 124 intermediate its ends pivotally supports an arm 128, the end of which carries a shaft 1~9 S which rotatably supports a metal roller 130 having a knurled outer surface. A spring 134 wrapped around the pin 126 bears with one end against the bracXet 124 and with the other end against the arm 128, so as to resiliently to urge the roller 130 into engagement with rubber rings 132 carried by clutch member 114.
The other clutch member 136 includes a disk-like portion on an integral axially extending hub portion 138 carried by a bushing 140 supported on the shaft 110. Ra-spective ball bearings 142 and 144, the inner rings of which are received on the hub 138 are held in spaced relationship by a spacer 146 located between the outer rings of the bearings, These bearings 142 and 144 are received in a recess 148 formed in the clutch member 114. Bearings 142 and 144 accurately space clutch member 114 in a radial direc-tion with reference to the hub 138 of the clutch m~mber 136.
As has been pointed out hereinabove, the key 116 permit~
soma radial movement o the clutch member 114 relative to the ~haft 110, thus to permit the bearings 142 and 144 to perEorm the function of accurately positioning the member 114 radially with reference to the hub 138 of the member 136.
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From the structure thus far descrioed, it will readily be apparent that shaft 110 continuously drives the member 114 owing to the connection therebetween provided by the key 116. Moreover, under the action of friction, member 136 likewise would tend to rotate w~ith the shaft 110. The clutch assembly is provided with means for normally restrain-ing member 136 against rotation with the shaft 110. Clutch ..,':
136 is formed with a cam 150 having a low point l50a followed by a rising portion 150b in the counterclockwise direction as viewed in FIGURE 6 and then a relatively sharp drop 150c.
Stud 120 rotatably supports a follower arm 154 carrying a follower 152 adapted to ~i~ against the cam 150. A spring 156 on the stud 120 normally urges the arm 154 to rotate in a clockwise direction as Yiewed in the drawings. In the - ~' inactive condition of the parts, follower 152 rests against in~
the lowll50a of the cam. In this condition the action of spring 156 on the arm 154 overcomes the frictional tendency of the clutch member 136 to rotate with clutch member 114, so that the clutch member 136 is stationary.
The disk-liXe portion of clutch member 136 i~
formed with a peripheral axially extending finger 158 which extend~for a predetermined distance around the disk-like portion of member 1360 It will be seen that finger 158 forms a narrow radial gap with member 114. The radial extent of the gap i~ accurately determined by the bearings 142 and , -.
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~ 144. In practice the spacing between the finger 158 and the ;` member 114 ~ay be of the order of two mils. We provlde a roughened surface portion 160 on the outer surPace of member 114 below the finger 115 and highly polish the inner surface 162 of the member 158. ~5 will more fully be explained here-.
inbelow, in operation of the clutch the surface 162 cooperates with the image bearing side of the copy sheet, while the surface 160 cooperates with the reverse side of the copy sheet. The space between the finger 158 and the member 114 - 10 is such that introduction of the leading edge of a sheet of common copy paper into the space between the finger and the member will clutch the finqer and the member together with sufficient force to overcome the influence of spring 156 to cause the two members to move together. Moreover, as the two members move together, follower 152 rides up the rise 150b, thus to increase the force with which the leading edge of the paper i8 gripped. As the paper is thus carried around with the two clutch elements in a clocXwise direction as viewed in the drawlngs, ultimately the sharp drop lSOc in the surface of cam 150 will arrive at the location of the , follower 152. As the follower 152 moved up the ri~e ~
the force stored in the spring 156 increases. Thus~ when the drop 150c arrives at the follower 152, thc spring 156 : - .
rapidly moves clutch member 136 and finger 158 carried thereby in a clockwlse, direction but more rapidly than the speed of rotation o f member 114, thus to release the portion : .
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of the leading edge of the copy which has been gripped by the clutch mechanism. It will readily be appreciated that the highly polished inner surface of finger 158 facilitates this releasing operation. At the time of this releasing operation, the leading edge of the paper has already moved into the nip between the knurled roller 130 and the rubber rings 132.
From this point, the copy paper is carried out of the machine by means of the delivery rolls B2 and 84. It i5 to be empha-- sized that under the action of the cam and follower, finger 158 is brought precisely back to the same location on each operation of the machine.
Our improved pi~k-off device includes a blade 164 formed of a ~uitable material which will not result in ex-, CQssiVe wear on the photoconductor. We may, for example, form the blade 164 from polytetrafluoroethylene copolymer or - ~ polyethylene terephthalate copolmcr. An opening 166 in the blade 164 receives a post or pin 168 carried by the finger 158 of the normally stationary clutch element. We secure an arcuate resilient retainer 170 to the finger 158 by means :. 20 of a rivet 172 or the like which passes through a spacer 174 between the retainer 170 and finger 158. A hole 176 in the ; retainer 170 receives an extension 178 on pin 168. It will readily be appreciated that the retainer 170 releasably hold~
the blade 16~ ln position on finger 158. ~he blade 164 can readily be removed and replaced by moving the retainer 170 .
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to the broken line position shown ln FIGURE 6.
Preferably, we form the lower part of the finger 164 as viewed in the drawings with a thickened portion 182 which obviates the danger of the leading edge of a sheet being directed toward the location at which the lower end of finger 158 as viewed in the drawings engages blade 164.
It will readily be appreciated that the occurrence of the event which i8 obviated by thickened portion 182 could easily result in a jam.
Thickened portion 182 terminates in a knife edge 180 adapted to engage the photoconductor drum surface. We provide the lower end of the blade 164 with a lateral taper 184 to minimize the line of contact between the knife edge 180 and the drum 16.
While the material of which our blade 164 is formed i~ Felatively rigid, it is also somewhat resilient.
Ir the pick-off assembly were displaced from the drum the blade 164 would assume the position shown in broken line in FIGURE 6. If the pick-off assembly is restored to its normal position adjacent to the drum, the blade 164 moves ; to the full line position shown in FIGURE 6. It will thu~
be seen that, in the operative position of the picX-off assembly the blade 164 is biased into engagement with the surface of drum 16 by virtue of the inhcrent resiliency o~
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tlle material o~ which the blade is made.
We provide the copy machine with which our pick-o~f ,; .
assembly is used with means for preventing sheets which are not picked off by -the pick-off assembly and more particularly second sheets resulting from doub:Le feeds from advancing to the cleaning roll 76 and becoming wrapped -therearound. A shoe 186 having a recess 188 is carried by a rod 190 supported on an actuator 192 connected to a sleeve 194 received by a vertically extending pin 96 on a bracket 198. When a sheet is not picked off by the pick-off assembly its leading edge enters recess 188 or engages actuator 192 to cause the actuator 192 to rotate around pivot pin 196. When this occurs, a wire 200 carried by the actuator operates a switch 202 carried by a bracket 204. This causes the machine to stop and activate a suitable indicator.
The operation of our improved pick-off device will readily be understood from the description hereinabove. So long as the drum 16 is being driven, shaft 110 is driven to drive clutch member 114. At the same time, the action of spring 156 prevents rotation of clutch member 136 with the member 114. After an image has been formed on the drum 16 - and developed, a '' , .
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sheet of copy material iq fed to the drum beneath the transfer corona 38. As the sheet moves past the tranqfer corona, the developed image migrates from the surface of the drum to the surface of the sheet in contact with the drum. As a sheet which has received the image moves out of the transfer loca-tion, its leading edge rides up the thickened portion 182 of blade 164 and is directed into the space between finger 158 and member 114. The thickened portion 182 directs the leading edge of the sheet away from the line of contact between the lower end of finger 158 and blade 164. Owing to the relation-ship of the thicXness of the sheet 168 to the space between finger 158 and member 114, as the leading edge of the sheet enters the space, the finger 158 and member 114 are clutched together to overcome the force of spring 156 and to cause lS the follower 152 to ride up the cam rise 150b. As thiq occurs, the sprlng is loaded to increase the force with which the leading edge o the paper is grasped between the finger 158 and the member 114. After a predetermined rotation of - member 114 to a location at which the leading edge of the paper has moved into the nip between roller 130 and ringq 132, the cam drop 150c has arrived at the location of follower 152. At this point the force of the loaded spring 156 move~
the member 136 and finger 158 in the same direction and at a greater ~peed than the member 114 to release the leading odgo of the sheet. As has been pointed out hereinabove, the highly polished surface 162 of finger 158 facilit~tes this , , $~
releasing action, At the and of the operation knife edge 180 returns to precisely the same position it occupied at ehe beginning.
, It addition to the foregoing, if by any chance a double feed occurs, the second sheet will be intercepted by shoe 1~6 or actuator 192, the machine will stop and the user will be informed of the malfunction.
It will be seen that we have accomplished the objects of our invention. we have provided a pick-off for a copying machine which overcomes the defects of pick-off systems of the prior art. Our pick-off device permits sub-stantially the entire area of the copy sheet to receive a transferred image. Our picX-off device is reliable in operation. Our pick-o~f arrangement incooperateS means for preventing a double fea sheet from becoming wrapped around the cleaninq roller of the machine. Our device successfully pick9 a copy sheet off the drum and delivers it to the customer without smudging any part of the formed image and without dirtying the copy. It is extremely reliable in operation.
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' It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of our claims. It I
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; understood that our invention i9 not to be limited to the speciic details shown and described.
Having thus described our invention, what we claim~ is:
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Claims (22)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a copying machine of the image transfer type in which an image developed on a surface is transferred to a sheet of copy material which moves with the surface through a transfer station to a pick-off station, pick-off apparatus including a first clutch element, means for driving said first clutch element, a second clutch element, means mounting said second clutch element for movement relative to said first clutch element with a narrow space between said elements, an opening leading into said narrow space, means positioning said clutch elements with said opening at a location adjacent to said surface, means including a blade carried by said second clutch element for movement therewith, said blade extending from said opening to a location at which it engages said moving surface to intercept the leading edge of a copy sheet moving with said surface to strip a portion of said sheet away from said surface and to direct said portion into the space between said elements, the relationship between the thickness of said sheet and the space between said elements being such that entry of said sheet into said space clutches said elements to each other for movement as a unit, and means responsive to a pre-determined movement of said elements as a unit for releasing said portion of a copy sheet.
2. Apparatus as in Claim 1 including means for biasing said blade into engagement with said surface.
3. Apparatus as in Claim 1 in which said blade is formed of low friction material.
4. Apparatus as in Claim 1 including means for manually detachably mounting said blade on said second clutch element.
5. Apparatus as in Claim 4 in which said mounting means comprises a resilient retainer.
6. Apparatus as in Claim 5 in which said mounting means comprises a post on said second clutch element, an opening in said blade for receiving said post and an opening in said retainer for receiving said post.
7. Apparatus as in Claim 1 in which said blade is formed with a knife edge at its end in engagement with said surface.
8. Apparatus as in Claim 7 in which said blade is tapered in the direction of its width adjacent to said knife edge.
9. In a copying machine of the image transfer type in which an image developed on a surface is trans-ferred to a sheet of copy material which moves with the surface through a transfer station to a pick-off station, pick-off apparatus including a first generally cylindrical clutch element, means for rotating said first clutch element, a second clutch element comprising an arcuate finger, means mounting said second clutch element for rotary movement relative to said first clutch element and with said finger in closely spaced relationship to said first clutch element to form a narrow space between said finger and said first clutch element with a mouth adjacent to said surface opening into said space, resilient means normally restraining said second clutch element against movement with said first clutch element, a blade carried by said finger for movement therewith, said blade extending from said mouth to a location at which it engages said moving surface when said second element is restrained against movement with said first element to intercept the leading edge of a copy sheet moving with said surface to strip a portion of said sheet away from said surface and to direct said portion into said mouth, the relationship between the thickness of said sheet and the narrowness of said space being such that entry of said sheet into said space clutches said elements to each other to overcome said resilient means to cause said elements to rotate as a unit, and means res-ponsive to a predetermined rotation of said elements as a unit for releasing said portion of said sheet.
10. Apparatus as in Claim 9 including means for biasing said finger into engagement with said surface.
11. Apparatus as in Claim 9 including means for manually releasably mounting said blade on said finger.
12. Apparatus as in Claim 11 in which said mounting means comprises a post on said finger, an opening in said blade for receiving said post and a resilient retainer secured to said finger and overlying a portion of said blade.
13. Apparatus as in Claim 12 including an opening in said retainer for receiving said post.
14. Apparatus as in Claim 9 in which said blade overlies said finger and extends beyond the end of said finger to said surface and in which said blade is formed with a thickened portion adjacent to said surface for directing the leading edge of a sheet away from the point at which said blade leaves the end of said finger.
15. Apparatus as in Claim 9 in which said blade is formed with a lateral taper adjacent to said surface to minimize the contact between said blade and said surface.
16. Apparatus as in Claim 9 in which said blade is formed with a knife edge which engages said surface in the restrained position of said first clutch element.
17. Apparatus as in Claim 9 in which said blade is formed from a low friction synthetic resin.
18. Apparatus as in Claim 9 in which said blade is formed with a knife edge at the end thereof remote from said finger, means mounting said blade on the outer surface of said finger such that a portion of said blade extends tangentially from said finger in a first position when said second clutch element is out of its restrained position, said knife edge engaging said surface in the restrained position of the second clutch element to move said portion of said blade to a second position in close conformity to the outer surface of said finger whereby said knife edge is biased into engagement with said surface.
19. Apparatus as in Claim 18 in which said mount-ing means comprises an arcuate retainer overlying a second portion of said blade other than said first-named portion and means for securing said retainer to said finger.
20. Apparatus as in Claim 19 in which said mounting means comprises a post on said finger, said second portion of said blade being formed with an opening for receiving said post, said retainer being resilient to permit the portion thereof overlying said second blade portion to be moved manually away from said finger to permit said blade to be removed from said post.
21. Apparatus as in Claim 18 in which said blade is formed with a thickened portion adjacent said knife edge to direct the leading edge of a sheet away from the location at which said first-named blade portion engages the end of said finger in the second position thereof.
22. In a copying machine of the image transfer type in which an image developed on a surface is transferred to a sheet of copy material which moves with the surface through a transfer station to a pick-off station, pick-off apparatus including a first clutch element, means for driving said first clutch element, a second clutch element, means mounting said second clutch element for movement relative to said first clutch element with a narrow space between said elements, an opening leading into said narrow space, means positioning said clutch elements with said opening at a location adjacent to said surface, means including a blade carried by said second clutch element and for movement therewith, said blade extending generally in the direction of movement of said first clutch element from said opening to a location at which it engages said moving surface to intercept the leading edge of a copy sheet moving with said surface to strip a portion of said sheet away from said surface and to direct said portion into the space between said elements, the relationship between the thickness of said sheet and the space between said elements being such that entry of said sheet into said space clutches said elements to each other for movement as a unit, and means responsive to a predetermined movement of said elements as a unit for advancing said second element relative to said first element to release said portion of a copy sheet.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US85824677A | 1977-12-07 | 1977-12-07 | |
| US858,246 | 1992-03-26 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1111099A true CA1111099A (en) | 1981-10-20 |
Family
ID=25327851
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA315,799A Expired CA1111099A (en) | 1977-12-07 | 1978-11-03 | Pick-off device for electrostatic copier |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS5486348A (en) |
| CA (1) | CA1111099A (en) |
| DE (1) | DE2852636A1 (en) |
| FR (1) | FR2411149A1 (en) |
| GB (1) | GB2009716B (en) |
| IT (1) | IT1192591B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4219270A (en) * | 1979-08-29 | 1980-08-26 | Xerox Corporation | Reproducing apparatus |
| JP6692438B2 (en) * | 2016-09-13 | 2020-05-13 | 三菱電機株式会社 | Semiconductor module |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5149732A (en) * | 1974-10-26 | 1976-04-30 | Ricoh Kk | TENSHAHOSHIKI DENSHIFUKUSHAKINO SHIITOBUNRISOCHI |
| CA1086785A (en) * | 1977-11-09 | 1980-09-30 | Savin Corporation | Pickoff device for copying machine |
-
1978
- 1978-11-03 CA CA315,799A patent/CA1111099A/en not_active Expired
- 1978-11-22 GB GB7845636A patent/GB2009716B/en not_active Expired
- 1978-12-05 IT IT30560/78A patent/IT1192591B/en active
- 1978-12-06 DE DE19782852636 patent/DE2852636A1/en not_active Withdrawn
- 1978-12-06 FR FR7834394A patent/FR2411149A1/en not_active Withdrawn
- 1978-12-07 JP JP15060678A patent/JPS5486348A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5486348A (en) | 1979-07-09 |
| GB2009716B (en) | 1982-04-07 |
| FR2411149A1 (en) | 1979-07-06 |
| DE2852636A1 (en) | 1979-06-13 |
| GB2009716A (en) | 1979-06-20 |
| IT1192591B (en) | 1988-04-20 |
| IT7830560A0 (en) | 1978-12-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |