US3380733A - Sheet-stripping apparatus - Google Patents

Sheet-stripping apparatus Download PDF

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Publication number
US3380733A
US3380733A US505905A US50590565A US3380733A US 3380733 A US3380733 A US 3380733A US 505905 A US505905 A US 505905A US 50590565 A US50590565 A US 50590565A US 3380733 A US3380733 A US 3380733A
Authority
US
United States
Prior art keywords
drum
xerographic
support material
sheet
manifold
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 - Lifetime
Application number
US505905A
Other languages
English (en)
Inventor
Vaidevutis C Draugelis
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xerox Corp
Original Assignee
Xerox Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Xerox Corp filed Critical Xerox Corp
Priority to US505905A priority Critical patent/US3380733A/en
Priority to LU52213D priority patent/LU52213A1/xx
Priority to FR81858A priority patent/FR1499560A/fr
Priority to ES332819A priority patent/ES332819A1/es
Priority to BE689067D priority patent/BE689067A/xx
Priority to GB48358/66A priority patent/GB1157342A/en
Priority to DK562566AA priority patent/DK112289B/da
Priority to NO165404A priority patent/NO122220B/no
Priority to AT1011466A priority patent/AT268045B/de
Priority to SE14927/66A priority patent/SE326103B/xx
Priority to CH1568166A priority patent/CH468661A/fr
Priority to NL666615334A priority patent/NL151191B/xx
Priority to DE19661522704 priority patent/DE1522704C3/de
Application granted granted Critical
Publication of US3380733A publication Critical patent/US3380733A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S271/00—Sheet feeding or delivering
    • Y10S271/90—Stripper

Definitions

  • VAIDEVUTIS C. DRAUGELIS A TTOR/VE Y April 30, 1968 V.
  • VAIDEVUTIS c. DRAUGELIS fl/M ATTORNEY April 30, 1968 v. c. DRAUGELIS 3,330,733
  • the apparatus includes a manifold having multiple parallel spaced discharge orifices supported in a non-parallel orientation with respect to the axis of rotation of the drum. Because of this orientation, when a jet of aeriform fiuid is discharged through the manifold and orifices against the leading edge of a copy sheet rotating toward the orifices, the leading edge is stripped from the drum in a sequential manner to separate the entire sheet from the drum.
  • This invention relates to sheet stripping apparatus and in particular to a sheet stripping mechanism for removing sheets of transfer material from a xerographic plate.
  • this invention relates to an improved sheet stripping apparatus utilizing jets of compressed aeriform fluid to strip a sheet of transfer material from a xerographic plate or similar device.
  • a xerographic plate comprising a layer of photoconductive material on a conductive backing is given a uniform electric charge over its surface and then exposed to the subject matter to be reproduced, usually by conventional projection techniques. This exposure discharges the plate in accordance with the light intensity reaching it thereby creating an electrostatic latent image on or in the plate.
  • developers which comprise, in general, a mixture of a suitable pigmented or dyed resin based powder, hereinafter referred to as toner, and a granular carrier material which functions to carry and to generate triboelectric charges on the toner. More specifically, the function of the carrier material is to provide mechanical control of the toner, or to carry the toner to an image surface and, simultaneously, provide almost complete homogenity of charge polarity.
  • the toner powder is brought into surface contact with the photoconductive coating and is held thereon electrostatically in a pattern corresponding to the latent electrostatic image. Thereafter, the developed xerographic image is usually transferred to a transfer or support material to which it may be fixed by any suitable means.
  • the toner particles which are many times smaller than the carrier particles, adhere to and coat the surface of the carrier particles due to the electrostatic attraction between them.
  • toner coated carrier particles roll or tumble over the xerographic plate carrying an electrostatic image of opposite polarity to the charge on the toner, toner particles are pulled away from the carrier by the latent electrostatic image and deposited on the plate to form a developed toner image.
  • the toner image is normally negatively charged and its transfer to the support material is effected by applying a positive charge to the non-image side of the support material by means of a transfer corotron, if the charged support material contacts a grounded portion of the machine, such as mechanical strip fingers, the toner powder images will explode, losing their image configuration.
  • Prior art sheet stripping apparatus for example, of the type disclosed in the J. Rutkus et al. patent, required that a sheet of support material be precisely registered in relation to the discharge of compressed aeriform fiuid from the stripper mechanism to effect removal of the sheet from the xerographic drum.
  • a device such as disclosed in the above-referenced patent, is very suitable.
  • the present invention comprises an improved sheet stripping apparatus having an increased latitude of operation for use in an automatic xerographic reproducing machine to strip a sheet of support material from the xerographie drum.
  • Another object of this invention is to improve sheet stripping apparatus utilizing compressed aeriform fluid to sequentially strip a portion of the support material from a xerographic drum.
  • a source of compressed aeriform fluid at substantially a constant pressure connected to a discharge manifold having multiple parallel spaced orifices.
  • the manifold is adapted to be positioned adjacent a xerographic drum at an angle to the drums axis of rotation whereby a sheet of transfer material adhering to the xerographic drum will be sequentially separated therefrom by jets of compressed aeriform fluid directed against the drum and leading edge of the sheet of support material.
  • FIG. 1 is a schematic diagram of an automatic xerographic reproducing machine utilizing an embodiment of this invention.
  • FIG. 2 is a horizontal elevation of the subject invention in a machine such as shown in FIG. 1 to better illustrate the cooperative relation thereof.
  • FIG. 3 is a side elevation view of the subject invention in a suitable environment such as the automatic xerographic reproducing machine of FIG. 1.
  • FIG. 4 is a front perspective view of an embodiment of the invention to more clearly illustrate the nature thereof.
  • FIG. 5 is a schematic diagram of the subject invention.
  • FIG. 1 there is shown an embodiment of the subject invention in a suitable environment such as an automatic xerographic reproducing machine having a xerographic plate including a photoconductive layer or light-receiving surface on a conductive backing and formed in the shape of a drum, which is mounted on a shaft journaled in a frame to rotate in the direction indicated by the arrow to cause the drum surface sequentially to pass a plurality of xerographic processing stations.
  • a xerographic plate including a photoconductive layer or light-receiving surface on a conductive backing and formed in the shape of a drum, which is mounted on a shaft journaled in a frame to rotate in the direction indicated by the arrow to cause the drum surface sequentially to pass a plurality of xerographic processing stations.
  • a charging station 1 at which a uniform electrostatic charge is deposited on the photoconductive layer of the xerographic drum;
  • An exposure station 2 at which a light or radiation pattern of copy to be reproduced is projected onto the drum surface to dissipate the drum charge in the exposed areas thereof thereby forming a latent electrostatic image of the copy to be reproduced;
  • a developing station 3 at which xerographic developing material, including toner particles having an electrostatic charge opposite to that of the electrostatic latent image, are cascaded over the drum surface, whereby the toner particles adhere to the electrostatic latent image to form a xerographic powder image in the configuration of the copy being reproduced;
  • a transfer station 4 at which the xerographic powder image is electrostatically transferred from the drum surface to a transfer or support material;
  • a drum cleaning and discharge station 5 at which the drum surface is brushed to remove residual toner particles remaining thereon after image transfer, and at which the drum surface is exposed to a relatively bright light source to effect substantially complete discharge of any residual electrostatic charge remaining thereon.
  • the powder images previously formed on the xerographic drum are electrostatically transferred to a sheet of support material, the electrostatic charge being applied to the support material by means of the corona transfer device 7.
  • the electrostatic charge applied to the support material during the transfer process is sufiicient to cause the support material to adhere to the drum even after the material has passed out of the corona emission area. It is apparent that there must be provided some means for removing the support material from the xerographic drum.
  • FIGS. 2, 3 and 4 A preferred form of a pick-off mechanism, constructed in accordance with the invention, is specifically illustrated in FIGS. 2, 3 and 4 and employs a manifold having multiple outlet orifices 27 directed against the surface 11 of the xerographic drum so that jets of compressed aeriform fluid from the orifices are directed against the leading edge of a sheet of support material to blow the edge of the material off of the drum, the remainder of the support material then peeling off the drum due to its own weight.
  • the manifold may be supplied with compressed aeriform fluid by means of any source of compressed aeriform fluid desirably at substantially constant pressure.
  • a discharge manifold 25 positioned adjacent to the drum 10 and at an angle to the drums axis of rotation 12 by means of brackets 21 which may be secured to a structural element of the machine, as for example, the drum cleaning device 22.
  • Multiple parallel spaced outlet orifices 27 secured on the manifold are positioned so that streams of compressed aeriform fluid emerging from the orifices are directed to stroke the surface of the Xerographic drum at an angle between the normal and the tangent to the drums surface.
  • the manifold 25 consists of tube 25 closed at one end and counterbored at the intake ends to receive the tube coupling 28 press fitted into place. Each orifice passes through the wall of tube 26 so that each is in communication with the interior thereof.
  • Compressed aeriform fluid is delivered to the manifold by means of a flexible tube 29 connected at one end to the manifold tube coupling 28 and its other end to the male hose connector 30 threaded into a solenoid valve 3 1 of any suitable commercial avail-able type.
  • the solenoid valve 31 is activated whenever a sheet of support material is forwarded to the xerographic drum closing a limit switch 15.
  • the valve is held open to allow the compressed aeriform fluid to be directed against the drum and leading edge of the support material for a suflicient time to allow the material to be sequentially removed from the drum without effecting the toner powder image electrostatically transferred to the support material, preferably 3 of the drum rotation.
  • Constant pressure compressed aeriform fluid is supplied to the manifold 25 through the solenoid valve 31 by means of an accumulator tank 35 and a compressor 36 as shown schematically in FIG. 5.
  • the compressor 36 operates to keep the accumulator tank 35 at a constant suitable pressure, preferably about 13 p.s.i. by means of a pressure relief valve 37.
  • a pressure switch 38 operates the compressor 36 whenever the accumulator tank pressure drops below a predetermined minimum and then interrupts operation when the pressure is again suitable.
  • the valve opens for about 0.036 second, which is equivalent to 3 of drum rotation, discharging the aeriforrn fluid at substantially a constant pressure, thereafter reclosing allowing the accumulator tank to again be brought up to the original pressure.
  • the toner powder image is substantially removed from the drum surface onto the support material by means of a corona transfer device 7 that is located at or immediately after the line of contact between the support material and the rotating drum.
  • the electrostatic field created by the corona transfer device is effective to tack the support material electrostatically to the drum surface, whereby the support material moves synchronously with the drum while in contact therewith.
  • the electrostatic field is effective to transfer the toner particles comprising the xerographic powder image from the drum surface and cause them to adhere electrostatically to the surface of the support material.
  • the latitude of stripping sheets would be determined by the length of time aeriform fluid is discharged through the manifold.
  • a method of increasing the latitude of sheet removal by increasing the duration of the discharge of aeriform fluid has the disadvantage of destroying the toner powder image on the support material if the duration of discharge is increased beyond a very limited time.
  • the range of removal of support material can be increased beyond the duration of time of discharge of compressed aeriform fluid, thereby allowing the discharge to be timed to prevent destruction of the toner powder image on the support material, but being capable of sufficient latitude to sequentially strip support material from the xerographic drum through an increased range of registration.
  • a discharge manifold having multiple parallel paced discharge orifices operatively connected to said source
  • timing means connected to said cyclically operative means to limit the duration of the jets of compressed aeriform fluid from said discharge orifices so that the powder image electrostatically adhering to said xerographic drum and to said transfer material is not dislodged therefrom.
  • a compressed aeriform fluid source means connected to said discharge manifold so that jets of compressed aeriform fluid may be directed by said discharge orifices against said xerographic drum to sequentially separate the leading edge of the support material from said xerographic drum, and
  • timing means to limit the duration of the jet streams from said orifices so that the powder adhering to the support material is not blown therefrom.
  • a sheet pick-off apparatus for the removal of support material superposed on a powder image previously formed on a xerographic drum with its leading edge extending beyond the powder image, the support material electrostatically adhering to the surface of said drum, said sheet pick-off apparatus including a manifold having multiple parallel spaced discharge orifices for the discharge of compressed aeriform fluid at substantially a constant pressure,
  • mounting means connected to said manifold to enable said manifold to be positioned adjacent to said drum at an angle to the drums axis of rotation with said discharge orifices of said manifold positioned to direct jets of compressed aeriform fluid against the surface of said drum in advance of the leading edge of support material thereon,
  • timing means to control said cyclically operative means whereby the duration of the flow of compressed aeriform fluid from said discharge orifices is limited so that the powder image adhering electrostatically to said support material is not dislodged therefrom.
  • a sheet pick-off apparatus for the removal of support material superposed on a powder image previously formed on a rotatable cylindrical xerographic surface, the support material electrostatically adhering to the xerographic surface, said sheet pick-01f apparatus including a manifold having multiple spaced discharged orifices for the discharge of compressed aeriform fluid against the xerographic surface,

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Cleaning In Electrography (AREA)
  • Sheets, Magazines, And Separation Thereof (AREA)
  • Separation, Sorting, Adjustment, Or Bending Of Sheets To Be Conveyed (AREA)
  • Printing Methods (AREA)
  • Electrostatic Charge, Transfer And Separation In Electrography (AREA)
US505905A 1965-11-01 1965-11-01 Sheet-stripping apparatus Expired - Lifetime US3380733A (en)

Priority Applications (13)

Application Number Priority Date Filing Date Title
US505905A US3380733A (en) 1965-11-01 1965-11-01 Sheet-stripping apparatus
LU52213D LU52213A1 (fr) 1965-11-01 1966-10-20
ES332819A ES332819A1 (es) 1965-11-01 1966-10-27 Metodo y aparato para separar un lamina de un material de soporte respecto a una placa xerografica.
FR81858A FR1499560A (fr) 1965-11-01 1966-10-27 Procédé et appareil pour enlever une feuille de matière de support d'un cliché xérographique mobile
GB48358/66A GB1157342A (en) 1965-11-01 1966-10-28 Apparatus for Stripping Sheets from Xerographic Plates
DK562566AA DK112289B (da) 1965-11-01 1966-10-28 Mekanisme til fjernelse af et ark fra en bevæget xerografisk plade.
BE689067D BE689067A (fr) 1965-11-01 1966-10-28
NO165404A NO122220B (fr) 1965-11-01 1966-10-31
AT1011466A AT268045B (de) 1965-11-01 1966-10-31 Verfahren und Einrichtung zum Ablösen von an einer Trägerfläche haftenden Blättern, insbesondere für xerographische Reproduktionsgeräte
SE14927/66A SE326103B (fr) 1965-11-01 1966-10-31
CH1568166A CH468661A (fr) 1965-11-01 1966-10-31 Procédé pour enlever une feuille de matière de support d'un cliché xérographique mobile
NL666615334A NL151191B (nl) 1965-11-01 1966-10-31 Inrichting voor het verwijderen van een vel materiaal van een bewegende xerografische trommel.
DE19661522704 DE1522704C3 (de) 1965-11-01 1966-11-02 Vorrichtung zum Abheben eines Kopierblattes von einer elektrofotografischen Bildplatte

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US505905A US3380733A (en) 1965-11-01 1965-11-01 Sheet-stripping apparatus

Publications (1)

Publication Number Publication Date
US3380733A true US3380733A (en) 1968-04-30

Family

ID=24012371

Family Applications (1)

Application Number Title Priority Date Filing Date
US505905A Expired - Lifetime US3380733A (en) 1965-11-01 1965-11-01 Sheet-stripping apparatus

Country Status (12)

Country Link
US (1) US3380733A (fr)
AT (1) AT268045B (fr)
BE (1) BE689067A (fr)
CH (1) CH468661A (fr)
DK (1) DK112289B (fr)
ES (1) ES332819A1 (fr)
FR (1) FR1499560A (fr)
GB (1) GB1157342A (fr)
LU (1) LU52213A1 (fr)
NL (1) NL151191B (fr)
NO (1) NO122220B (fr)
SE (1) SE326103B (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3506259A (en) * 1967-10-12 1970-04-14 Xerox Corp Electrostatic sheet detacking apparatus
US3811670A (en) * 1972-06-19 1974-05-21 Xerox Corp Electrostatographic apparatus with air baffle
US3857560A (en) * 1973-07-23 1974-12-31 Xerox Corp Adhesive paper pick-off system
US3867026A (en) * 1970-08-03 1975-02-18 Minolta Camera Kk Electrophotographic copier of transfer type
US3907280A (en) * 1972-06-23 1975-09-23 Rank Xerox Ltd Flexible sheet handling device
US3914041A (en) * 1972-12-01 1975-10-21 Zindler Lumoprint Kg Copy sheet guidance device for photo-copying machines

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2132132A (en) * 1935-08-09 1938-10-04 Seat Jay Lawrence Fire extinguisher system
US2905465A (en) * 1956-10-08 1959-09-22 Magnavox Co Card processing apparatus
US3090616A (en) * 1959-07-02 1963-05-21 Rolf W Eichler Sheet handling control apparatus

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2132132A (en) * 1935-08-09 1938-10-04 Seat Jay Lawrence Fire extinguisher system
US2905465A (en) * 1956-10-08 1959-09-22 Magnavox Co Card processing apparatus
US3090616A (en) * 1959-07-02 1963-05-21 Rolf W Eichler Sheet handling control apparatus

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3506259A (en) * 1967-10-12 1970-04-14 Xerox Corp Electrostatic sheet detacking apparatus
US3867026A (en) * 1970-08-03 1975-02-18 Minolta Camera Kk Electrophotographic copier of transfer type
US3811670A (en) * 1972-06-19 1974-05-21 Xerox Corp Electrostatographic apparatus with air baffle
US3907280A (en) * 1972-06-23 1975-09-23 Rank Xerox Ltd Flexible sheet handling device
US3914041A (en) * 1972-12-01 1975-10-21 Zindler Lumoprint Kg Copy sheet guidance device for photo-copying machines
US3857560A (en) * 1973-07-23 1974-12-31 Xerox Corp Adhesive paper pick-off system

Also Published As

Publication number Publication date
DE1522704B2 (de) 1975-10-09
DE1522704A1 (de) 1969-10-16
BE689067A (fr) 1967-04-28
LU52213A1 (fr) 1967-04-20
SE326103B (fr) 1970-07-13
NL151191B (nl) 1976-10-15
FR1499560A (fr) 1967-10-27
AT268045B (de) 1969-01-27
GB1157342A (en) 1969-07-09
ES332819A1 (es) 1968-03-16
DK112289B (da) 1968-11-25
NL6615334A (fr) 1967-05-02
NO122220B (fr) 1971-06-01
CH468661A (fr) 1969-02-15

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