US3837640A - Stripper finger with air cushion - Google Patents

Stripper finger with air cushion Download PDF

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Publication number
US3837640A
US3837640A US00306238A US30623872A US3837640A US 3837640 A US3837640 A US 3837640A US 00306238 A US00306238 A US 00306238A US 30623872 A US30623872 A US 30623872A US 3837640 A US3837640 A US 3837640A
Authority
US
United States
Prior art keywords
finger
drum surface
drum
stripping
copy sheet
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
US00306238A
Other languages
English (en)
Inventor
J Norton
H Schmalzbauer
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 US00306238A priority Critical patent/US3837640A/en
Priority to BR826673A priority patent/BR7308266D0/pt
Priority to GB4952573A priority patent/GB1427058A/en
Priority to IT3057173A priority patent/IT998964B/it
Priority to NL7314842A priority patent/NL7314842A/xx
Priority to FR7338663A priority patent/FR2204824B1/fr
Priority to DE19732354387 priority patent/DE2354387C3/de
Priority to JP48124081A priority patent/JPS529388B2/ja
Priority to CA185,484A priority patent/CA1002077A/en
Application granted granted Critical
Publication of US3837640A publication Critical patent/US3837640A/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

  • ABSTRACT A stripping apparatus for stripping copy sheets from the surface of the xerographic drum without destroying the developed latent electrostatic image on the copy sheet and without contacting the drum surface.
  • a stripping finger is mounted on a linkage which is supported from the machine frame to position the finger in close proximity with the drum surface.
  • the finger has a tip portion which protrudes slightly past the point of tangency of the finger with the drum surface.
  • Small apertures are formed at the bottom of the finger which is hollow and is in communication with an air supply to cause an air cushion to be formed under the finger.
  • the finger floats on an air cushion which is maintained at a predetermined distance from the drum surface.
  • a tiny channel formed in the forward surface of the tip is in communication with the air supply and provides sufficient pressure to blow developer material away from the tip to maintain it in clean condition.
  • the linkage is arranged to exert a pressure biasing action on the tinger in the direction normal to the direction of drum movement.
  • This invention generally relates to xerography, and, in particular to an improved apparatus for stripping a paper support material having an electrostatically transferred toner image thereon from a moving photoconductive surface.
  • a photoconductive surface In conventional xerography, a photoconductive surface is uniformly charged and the charged surface then exposed to a light image of an original to be reproduced. Under the influence of the light image, the charge on the surface is selectively dissipated to produce what is known as a latent electrostatic image.
  • the charged latent image is developed, or made visible, by attracting oppositely charged toner particles which are brought into close proximity to the plate surface, into the image areas.
  • the developed image is then generally transferred to a paper support material and the image affixed thereto to form a permanent record of the original document.
  • the copy sheet is placed over the image bearing photoconductive surface and the backside of the sheet subjected to a spray of ionized air.
  • a charge is built up on the sheet having a magnitude and polarity sufficient to electrostatically attract the toner particles from the photoconductive surface to the copy sheet.
  • a charge opposite to the charge found in the non-imaged areas on the drum surface is induced in the paper causing the copy sheet to become electrostatically tacked to the drum surface. Removal of the copy sheet and. the toner image loosely adhering thereto has long been a problem in the xerographic art.
  • One of the best known and most widely used stripping devices is the mechanical air puffer.
  • the copy sheet is stripped from the surface by introducing a stream of air between the copy sheet and the surface and then allowing the sheet to fall away from the photoconductive surface where it can be picked up by a transport belt or the like. While puffing devices are satisfactory in some respects, they are not entirely reliable in operation.
  • Another stripping device is an array of mechanical fingers which are actuated by an electrical signal into contact with the photoconductor surface so as to contact the paper edge and wedge the edge away from the photoconductive surface.
  • these stripping fingers are made out of plastic materials or are plastic coated to prevent scoring or abrading the photoconductive surface. It has been found, however, that due to contact with the drum surface that the fingers wear quickly requiring frequent replacement due to the fact that they cannot remain in their sharp configuration which is necessary for the wedging effect.
  • An example of a mechanical stripping finger is described in US. Pat. No. 3,578,859.
  • the present invention is an improved stripping finger over existing stripping fingers and in particular is an improvement over copending application Ser. No. 247,064, filed Apr. 24, 1972, entitled Stripper Finger and commonly assigned herewith.
  • FIG. 2 is an isometric view of the stripping assembly of the invention
  • FIG. 3 is a side sectional view of the stripping assembly shown in FIG. 2;
  • FIG. 4 is plan view of the stripping assembly
  • FIG. 5 is an enlarged side elevation of the stripping assembly illustrating the operation thereof.
  • FIG. 1 For a general understanding of the illustrated copier reproduction machine in which the invention is incorporated, reference is had to FIG. 1 in which the various system components for the machine are schematically illustrated.
  • a light image of a document to be reproduced is projected onto the sensitized surface of a xerographic plate to form an electrostatic latent image thereon.
  • the latent image is developed with an oppositely charged developing material to form a xerographic powder image, corresponding to the latent image on the plate surface.
  • the powder image is then electrostatically transferred to a support surface to which it is fused by a fusing device whereby the powder image is caused permanently to adhere to the support surface.
  • an original to be copied is placed upon a transparent support platen P fixedly arranged in an illumination assembly and image rays are projected by means of an optical system for exposing the photosensitive surface of a xerographic plate in the form of a drum generally indicated by the reference numeral 10.
  • the drum 10 is mounted upon the frame of the machine and is adapted to rotate in the direction of the arrow at a constant rate. During this movement of the drum, it passes a charging station A where a uniform electrostatic charge is applied to the surface thereof. Next at an exposure station B exposure of the drum surface to the light image discharges the xerographic plate in a latent electrostatic image in image configuration corresponding to the light image projected from the original on the supporting platen. As the drum surface continues its movement, the electrostatic image passes through a developing station C in which there is positioned a developer assembly. The developer assembly deposits developing material to the upper part of the drum whereat the material is directed to cascade over the drum surface in order to provide development of the electrostatic image. As the developing material is cascaded over the drum surface, toner particles in the development material are deposited on the surface to form powder images.
  • the sheet After the sheet is stripped from the drum by a stripping assembly 20, as will be described more fully hereinafter, it is conveyed to a fuser apparatus generally indicated by the reference numeral 15 where the developed and transferred xerographic powder image on the sheet material is discharged from the apparatus by a belt conveyor to a suitable point for collection externally of the apparatus.
  • Suitable drive means are arranged to drive the drum in conjunction with timed exposure of an original to be copied, to effect conveying and cascade of toner mate rial, to separate and feed sheets of paper and to transport the same across the transfer station D and to convey the sheet of paper through the fuser apparatus in timed sequence to produce copies of the original.
  • a preferred material is Fotoceram, a registered trademark of Corning Glass Works, Corning, NY.
  • tiny apertures 28 are formed in segemented portions 30 arranged in the upper surface of the stripper finger member to effect an air cushion between the drum surface and finger member.
  • Stripper finger member 26 is supported on a rigid conduit member 37 received in support member 25 which pivotally supports the stripper finger member on an axis through the conduit member.
  • conduit member 36 Connected to conduit member 36 is a flexible tube'member 38 which is connected to a conduit member 41 received in support member 22.
  • Conduit member 41 is connected to a source of pressurized air (not shown).
  • a channel 45 is formed tip portion 27 of the stripper finger member.
  • the purpose of channel 45 is to direct a jet of air along the tip portion to remove any loose developer material therefrom.
  • the stripper finger member is supported on an air cushion at a distance ranging from between 0.0005 to 0.0015 inches during the stripping operation which is satisfactory for stripping most paper thickness and weights.
  • the air cushion supports the stripper at a uniform distance from the drum surface due to the action of the springs 32 and 34, which serve to urge the stripper finger upwardly into contact with the drum surface. Movement of the finger member normal to the drum is effected by pivoting on the axis through conduit member 32.
  • the tip portion of the stripping finger member extends slightly beyond the point of tangency to the drum surface. In this manner the tip strips the leading edge of the sheet from the drum surface.
  • the stripper finger does not contact the drum surface during the stripping operation, but is held therefrom at a distance which may be adjusted by regulating the air pressure. It has been found that pressure ranging from about 10-12 PSI work well. The finger will not damage or otherwise abrade the drum surface. Moreover, due to the pressurized air acting on the tip portion of the stripper finger, residual toner normally left on the drum surface will not collect on the tip portion which in the past has been responsible for mis-stripping. In addition to these advantages, the stripping finger of the invention has the ability to strip skewed copy sheets from the drum surface.
  • the stripping finger of the present invention is a significant advance in the copying, and in particular, is highly advantageous over the existing stripping devices used in xerographic copying machines.
  • a stripper finger member mounted on said resilient linkage means at a distance from a drum surface less than the thickness of each copy sheet to be stripped, said finger member having a tip portion extending in a linear direction slightly past a point of tangency with the drum surface, said finger member further having an array of apertures formed therein on one surface thereof facing the drum surface, and
  • air supply means providing low pressure air in communication with the apertures to cause an air cushion to be formed between the finger member and the drum surface acting against said resilient linkage means and spring bias means to maintain uniform spacing therebetween during the stripping operation to enable stripping of the copy sheet with developed images thereon by said tip portion without contacting the drum surface.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Cleaning In Electrography (AREA)
US00306238A 1972-10-30 1972-11-13 Stripper finger with air cushion Expired - Lifetime US3837640A (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
US00306238A US3837640A (en) 1972-11-13 1972-11-13 Stripper finger with air cushion
BR826673A BR7308266D0 (pt) 1972-10-30 1973-10-23 Aparelho aperfeicoado para remover folhas de copia contendo imagens eletrostaticas reveladas
GB4952573A GB1427058A (en) 1972-10-30 1973-10-24 Stripping apparatus
IT3057173A IT998964B (it) 1972-10-30 1973-10-25 Apparecchiatura per la separazione dei fogli particolarmente per macchine da stampa
NL7314842A NL7314842A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1972-10-30 1973-10-29
FR7338663A FR2204824B1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1972-10-30 1973-10-30
DE19732354387 DE2354387C3 (de) 1972-10-30 1973-10-30 Abstreifvorrichtung zum Entfernen eines Blattes Kopierpapier von der Trommeloberfläche eines xerographischen Kopiergerätes
JP48124081A JPS529388B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1972-11-13 1973-11-06
CA185,484A CA1002077A (en) 1972-11-13 1973-11-09 Stripper finger with air cushion

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00306238A US3837640A (en) 1972-11-13 1972-11-13 Stripper finger with air cushion

Publications (1)

Publication Number Publication Date
US3837640A true US3837640A (en) 1974-09-24

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
US00306238A Expired - Lifetime US3837640A (en) 1972-10-30 1972-11-13 Stripper finger with air cushion

Country Status (3)

Country Link
US (1) US3837640A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
JP (1) JPS529388B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
CA (1) CA1002077A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2300361A1 (fr) * 1975-02-10 1976-09-03 Xerox Corp Dispositif pour
US4119307A (en) * 1977-06-20 1978-10-10 Xerox Corporation Sheet stripping apparatus
US4219270A (en) * 1979-08-29 1980-08-26 Xerox Corporation Reproducing apparatus
US4806985A (en) * 1986-07-11 1989-02-21 Xerox Corporation Stripper fingers
US5211391A (en) * 1991-09-19 1993-05-18 Eastman Kodak Company Air flow assisted material removal method and apparatus
US20050156377A1 (en) * 2004-01-21 2005-07-21 Xerox Corporation Fuser sheet stripping system
US20080193176A1 (en) * 2007-02-13 2008-08-14 Xerox Corporation Air knife system with pressure sensor

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5539839B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) * 1972-12-23 1980-10-14
JPS5029046A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) * 1973-07-17 1975-03-24

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1595478A (en) * 1920-05-25 1926-08-10 Minton Ogden Method of stripping and feeding paper and apparatus
US3126200A (en) * 1960-07-30 1964-03-24 Separating device
US3396235A (en) * 1963-09-09 1968-08-06 Xerox Corp Xerographic facsimile printer having light scanning and electrical charging
US3578859A (en) * 1969-07-03 1971-05-18 Xerox Corp Mechanical stripping apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1595478A (en) * 1920-05-25 1926-08-10 Minton Ogden Method of stripping and feeding paper and apparatus
US3126200A (en) * 1960-07-30 1964-03-24 Separating device
US3396235A (en) * 1963-09-09 1968-08-06 Xerox Corp Xerographic facsimile printer having light scanning and electrical charging
US3578859A (en) * 1969-07-03 1971-05-18 Xerox Corp Mechanical stripping apparatus

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2300361A1 (fr) * 1975-02-10 1976-09-03 Xerox Corp Dispositif pour
US3981085A (en) * 1975-02-10 1976-09-21 Xerox Corporation Air stripping device for elastomeric surface
US4119307A (en) * 1977-06-20 1978-10-10 Xerox Corporation Sheet stripping apparatus
US4219270A (en) * 1979-08-29 1980-08-26 Xerox Corporation Reproducing apparatus
US4806985A (en) * 1986-07-11 1989-02-21 Xerox Corporation Stripper fingers
US5211391A (en) * 1991-09-19 1993-05-18 Eastman Kodak Company Air flow assisted material removal method and apparatus
US20050156377A1 (en) * 2004-01-21 2005-07-21 Xerox Corporation Fuser sheet stripping system
US20080193176A1 (en) * 2007-02-13 2008-08-14 Xerox Corporation Air knife system with pressure sensor
US7505723B2 (en) 2007-02-13 2009-03-17 Xerox Corporation Air knife system with pressure sensor

Also Published As

Publication number Publication date
JPS49102352A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1974-09-27
JPS529388B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1977-03-15
CA1002077A (en) 1976-12-21

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