US3834861A - Pressure heated fuser assembly - Google Patents

Pressure heated fuser assembly Download PDF

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Publication number
US3834861A
US3834861A US00343610A US34361073A US3834861A US 3834861 A US3834861 A US 3834861A US 00343610 A US00343610 A US 00343610A US 34361073 A US34361073 A US 34361073A US 3834861 A US3834861 A US 3834861A
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US
United States
Prior art keywords
roller
fuser
rollers
pressure
move
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
US00343610A
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English (en)
Inventor
Carroll A Mc
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
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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 US00343610A priority Critical patent/US3834861A/en
Priority to CA189,749A priority patent/CA1020218A/en
Priority to GB1157874A priority patent/GB1424307A/en
Priority to FR7409696A priority patent/FR2222681B1/fr
Priority to NL7403874A priority patent/NL7403874A/xx
Application granted granted Critical
Publication of US3834861A publication Critical patent/US3834861A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • G03G15/20—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat
    • G03G15/2003—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat
    • G03G15/2014—Apparatus for electrographic processes using a charge pattern for fixing, e.g. by using heat using heat using contact heat
    • G03G15/2017—Structural details of the fixing unit in general, e.g. cooling means, heat shielding means
    • G03G15/2032—Retractable heating or pressure unit
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/20—Details of the fixing device or porcess

Definitions

  • ABSTRACT An electrostatographic type reproduction machine having a fuser for fixing developed images on the copy material, the fuser having cooperating heated and pressure rollers.
  • the pressure roller is supported for movement away from the other roller to permit the rollers to be separated and the fuser unloaded.
  • the pressure roller is carried in a pivotable frame driveable by cams into physical contact with the heated roller.
  • a spring type return driver which is loaded on movement of the pressure roller into contact with the heated roller, serves when unlatched, to rapidly drive the fuser rollers apart.
  • an adjustable pneumatic dampener is provide to retard separating movement of the fuser rollers.
  • This invention relates to a pressure heated fuser for electrostatographic type reproduction machine, and more particularly to an improved fuser release mechanism.
  • a xerographic surface comprising a layer of photoconductive insulating material affixed to a conductive backing, is used to support electrostatic images.
  • the xerographic plate is electrostatically charged uniformly over its surface and then exposed to a light pattern of the image being reproduced to thereby discharge the charge in the areas where light strikes the layer.
  • the undischarged areas of the layer thus form an electrostatic charge pattern in conformity with the configuration of the original light pattern.
  • the latent electrostatic image may then be developed by contacting it with a finely divided electrostatically 'attractable material, such as a resinous powder.
  • a finely divided electrostatically 'attractable material such as a resinous powder.
  • the powder is held in the image areas by the electrostatic fields on the layer. Where the field is greatest, the greatest amount of material is deposited, and where the field is least, little or no material is deposited.
  • a powder image is produced in comformity with the light iamge of the copy being reproduced.
  • the powder is subsequently transferred to a suitable surface such as a sheet of paper or other surface and suitably affixed, such as by heat, pressure, and the like to thereby form a permanent print.
  • the aforesaid powder maybe fixed by exposing the image bearing sheet to heat and/or pressure, normally effected by a fuser.
  • a fuser consists of cooperating heated and pressure rollers, the rollers forming a nip through which the image bearing sheet is passed and thereby fixed.
  • the fuser heated roller is generally formed of a metallic substrate for high heat transfer efficiency, whereas the pressure roller is formed with a flexible surface material to provide a sufficiently wide nip when placed in contact with the fuser roller to efficaciously fuse the powder.
  • prolonged contact of the heated roller directly with the pressure roller in the absence of paper may be deleterious to the flexible surface material of the pressure roller. This may occur when the machine is in standby mode.
  • a release mechanism may be provided therefor.
  • One type of fuser release mechanism employs one or more relatively strong springs to effectuate such release, the arrangement being such that the springs are compressed into a bias condition upon movement of the fuser rollers into operating contact, such spring disposition being maintained by a suitable latch.
  • the latch isreleased and the fuser rollers spring apart.
  • Another object of this invention is to provide an improved apparatus for releasing fusing and pressure rollers in the fuser of an electrostatographic machine.
  • Still another object of the invention is to provide a novel apparatus for retarding the release motion of the fusing elements of a copying machine to reduce shock loads and noises resulting therefrom.
  • a still further object of the invention is to provide a reliable release assembly for the heated fusing and pressure rollers of a reproduction machine fuser to cushion the shock of the roller parts.
  • This invention relates to a fusing apparatus adapted for use with reproduction machines, the combination comprising; cooperating first and second rollers adapted to form a nip through which copies being fused pass, at least one of the rollers being heated; means supporting the first roller for movementinto and out of cooperative pressure relationship with the second roller; drive means adapted when actuated to move the first roller into pressure relationship with the second roller; bias means adapted when loaded and activated to move the first roller away from the second roller, the drive means serving when actuated to load the bias means; means for locking the rollers in pressure relationship with the bias means in a pre-set loadedcon'dition ready to move the first roller away; means to release the locking means and activate the bias means to move the first roller away; and motion control means to retard movement of the first roller under the influence of the bias means whereby to reduce shock loads on the apparatus attending subsequent stopping of the first roller.
  • FIG. 1 is a schematic sectional view of an exemplary electrostatic reproduction machine embodying the improved fuser of the present invention
  • FIG. 2 is a side view of the fuser pressure roller assembly illustrating the position of the pressure roller in an image transfer mode
  • FIG. 3 is a partial sectional isometric view of the fuser and the fuser release mechanism showing detail of the dampener of the present invention
  • FIG. 4 is an enlarged exploded isometric view showing details of the fuser release mechanism.
  • FIG. 5. is a side sectional view of the dampener of the present invention.
  • FIG. 1 of the drawings For a general understanding of the invention, an exemplary reproduction or copying machine, designated generally by the numeral 10, is schematically shown in FIG. 1 of the drawings.
  • documents 11 to be copied are placed one at a time upon the transparent support platen 12 fixedly arranged in an illumination assembly generally indicated by the reference numeral 14 (at the left end of the machine as seen in FIG. 1).
  • Light rays from suitable illuminators, for example flash lamps 15, are flashed upon the document 11 resting on platen 12 that produce image rays corresponding to the document informational areas.
  • the image rays are projected by ineans of a suitable optical system 16 onto the photosensitive surface of a xerographic plate.
  • the xerographic plate is in the form of a flexible belt 18 supported on a belt assembly, generally indicated by the reference numeral 19.
  • Belt 18 comprises a photoconductive layer of selenium which is the light receiving surface and imaging medium for the apparatus, on a flexible conductive backing.
  • the surface of the photoconductive belt is made photosensitive by a previous step of uniformly charging the same by means of a corona generating device or corotron 20.
  • Belt 18 is movably supported by rollers 21, 22, 23 of belt assembly 19, rollers 21, 22, and 23 being positioned with their axes substantially parallel to one another.
  • Belt assembly 19 is slideably mounted as a unit 1 upon support shafts 24 and 25, roller 23 being rotatably supported on shaft 24.
  • Shaft 24 is in turn secured to the machine frame and is rotatably driven by a suitable motor and drive assembly (not shown) in the direction of the arrow at a constant rate during the copying cycle.
  • the portion of the moving belt exposed that portion of the belt running between rollers 21 and 22
  • the exposure area is designated by the numeral 26.
  • development assembly 28 serves to develop the electrostatic image with a suitable electroscopic powder, commonly known as toner, by means of multiple brushes 29.
  • the developed electrostatic image on belt 18 next moves to a transfer station 30 whereat the image is transferred from belt 18 to a sheet of copy paper 31 by means of a transfer roller 34.
  • Sheet 31 is fed at a speed in synchronism with the belt 18 to avoid smearing or blurring of the image, transfer of the developed image being effected through the electrical bias on the transfer roller 34 in a manner known to those skilled in the art.
  • a sheet transport mechansim, generally indicated at 33, is provided to feed sheets 31 from paper supply tray 35 to transfer station 30.
  • the sheet is separated from belt 18 and is conveyed to a fuser assembly, generally indicated by the reference numeral 36, wherein the developed and transferred xerographic powder image on sheet 31 is permanently fused or fixed. After fusing, the finished copy is discharged from the apparatus into tray 38.
  • the fuser assembly 36 is comprised of a fuser roller 40 and a pressure roller assembly, generally indicated as 42.
  • Pressure roller assembly 42 includes pressure roller 43.
  • the fuser roller 40 is formed of a suitable heated conductive material, such as copper, and is provided with a source of heat 44, such as quartz lamp, centrally positioned therein to heat the roller 40 to operational temperatures.
  • the pressure roller 43 is mounted for rotation in end plates 46.
  • a support bar 47 and a cam follower shaft 48 including suitable cam followers 49, are mounted on end plates 46.
  • a pivot shaft 50 is affixed to and extends through the end plate 46 and is mounted for rotation in the fuser frame assembly, generally indicated as 52.
  • a cam assembly generally indicated as 60 has earns 62 mounted on a cam shaft 63.
  • Shaft 63 is journaled in frame member pair 52, 52" one end of shaft 63 projecting therebeyond and having gear 64 mounted thereon.
  • Gear 64 includes an internally formed stop 65.
  • Gear 64 engages a drive gear 66, as more fully hereinafter described.
  • a switch cam 67 positioned on shaft 63 in juxtaposition with switch assembly 68, is provided. As will appear, switch assembly 68 controls operation of latching solenoid 86 and the driving clutch 89 for gear 66.
  • a latch 70 having a latching surface 72 is mounted for rotation on the adjoining frame member 52' as by screw pin 74 such that, on raising of latch 70, the latching surface 72 inter-engages with surface 65' of stop 65 to prevent rotation of cam shaft 63 in the direction shown by the dotted line arrow in FIG. 4.
  • Spring 76 biases lock 70 away from latch 70 (downward as seen in FIG. 4).
  • Lever 80 positioned below the lock 70, is mounted for rotation on frame member 52 as by screw pin 82. One end of lever 80 is coupled to armature 84 of solenoid 86. Lever 80 has a pin-like abutment 81 adapted to engage the surface of latch 70 and thereby move latch 70 upwardly into latching engagement with stop 65 upon activation of solenoid 86.
  • a torsion spring 88 (more than one may be em-.
  • dampener 90 includes a tubular housing or shell 91 secured to frame member 52" as by support member 93 fixed to and projecting from frame member 52". Received in one end of housing 91 is a piston rod member 94 which is formed with teeth 96 at one end thereof. At the other end the rod member has a sealing ring 97 to ensure a snug fit in housing 91.
  • Screw member 103 has an extension 105 which is tapered so as to fit within orifice 99. Also formed in that end of the housing is a channel in communication with the atmosphere. The end teeth 96 on rod member 94 upon rotation of the shaft. By this structure the rod member is extended to the position shown in FIG. 5 when the fuser rollers areoperating and when released the rod member is cushioned with increasing force as the air pressure within housing builds up above atmospheric pressure due to compression against the rod member upon release. Screw member 103 is adjustable to control the amount of load cushioning desired and has a spring 104 to offset any vibrations.
  • the fuser heating element 44 is energized to heat the fuser roller 40 to a desired temperature at which time the reproduction machine 10 shifts to a standby mode ready to be placed in an image transfer mode.
  • Generation of a signal to place the machine in production energizes drive olutch 89, to turn gear 66.
  • Gear 66 in turn drives gear 64 to turn cam shaft 63 and cams 62 thereon in a clockwise direction as shown by the arrow in FIG. 4.
  • cam shaft 63 On rotation of cam shaft 63, earns 62 thereon work against followers 49 to swing pressure roll assembly 42 about the axis of pivot shaft 50 (counterclockwise in FIG. 2) to bring pressure roller 43 into contact with fuser roller 40.
  • switch cam 67 actuates the switch assembly 68 to disengage clutch 89, interrupting power to gear 66.
  • switch assembly 68 energizes solenoid 86. Energization of the solenoid 86 draws armature 84 thereof upwardly thereby lifting lever 80 and raising latch 70 to a point where the latching surface 72 thereof engages surface 65 of stop 65.
  • solenoid 86 Upon generation of a signal indicative of the completion of fusing solenoid 86 is de-energized. This permits spring 76 to move latch surface 72 out of interferring relationship with cam stop 65 thereby releasing torsion spring 88. Spring 88 accordingly unwin ds to rotate cam shaft 63 in a counterclockwise direction as shown by the dotted line arrow in FIG. 4 to move pressure and fuser rollers 43, 40, respectively, apart. Fuser 36 therfore returns to a standby condition.
  • torsion spring 88 In order to effect immediate separation of fuser and pressure rollers 40, 43, respectively may be necessary in the event ofa malfunction, against the relatively large mass inertia of the pressure roll of assembly 42, torsion spring 88 must be relatively powerful. The use of a relatively powerful spring for this purpose tends however to overdrive the pressure roller assembly 42 such that the stop ramps 62 on cam 62 strike against cam followers 49 with substantial force and impact.
  • Dampener 90 obviates this problem by retarding acceleration of cam shaft 63 under the impetus of spring 88, dampener 90 resisting the tendency of cam shaft 63 to accelerate at too great a rate.
  • dampener 90 permits initial acceleration of the pressure roller assembly 42 to assure timely separation of the pressure and fuser rollers 43, 40, respectively, in the event of a malfunction.
  • the dampener is reliable and does not leak in the sense of a liquid system subject to stresses.
  • a pressure roll fuser apparatus adapted for use with copy producing machine, said fusing apparatus including cooperating first and second rollers adapted to form a nip through which copies being fused pass with one of said rollers being heated, the combination of;
  • bias means adapted when loaded and activated to move said first roller away from said second roller, said drive means serving when actuated to load said bias means;
  • pneumatic dampener means operable on release of said locking means to cushion the load of said first roller under the influence of said bias means upon subsequent stopping of said first roller and movement away from said second roller;
  • said pneumatic dampener means comprising a housing receiving a sliding piston member which engages said drive means, said housing being formed with an orifice in communication with the atmosphere, and
  • an adjustable needle member operatively movable into and out of said orifice to vary the opening thereof.
US00343610A 1973-03-21 1973-03-21 Pressure heated fuser assembly Expired - Lifetime US3834861A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US00343610A US3834861A (en) 1973-03-21 1973-03-21 Pressure heated fuser assembly
CA189,749A CA1020218A (en) 1973-03-21 1974-01-09 Pressure heated fuser assembly
GB1157874A GB1424307A (en) 1973-03-21 1974-03-15 Pressure heated fuser assembly
FR7409696A FR2222681B1 (xx) 1973-03-21 1974-03-21
NL7403874A NL7403874A (xx) 1973-03-21 1974-03-21

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00343610A US3834861A (en) 1973-03-21 1973-03-21 Pressure heated fuser assembly

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US3834861A true US3834861A (en) 1974-09-10

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US00343610A Expired - Lifetime US3834861A (en) 1973-03-21 1973-03-21 Pressure heated fuser assembly

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US (1) US3834861A (xx)
CA (1) CA1020218A (xx)
FR (1) FR2222681B1 (xx)
GB (1) GB1424307A (xx)
NL (1) NL7403874A (xx)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3907493A (en) * 1974-07-11 1975-09-23 Xerox Corp Visco-elastic dampener mechanism for fuser assembly
US4110068A (en) * 1977-02-22 1978-08-29 International Business Machines Corporation Hot roller fuser having manually operable jam clearance mechanism
EP0000632A1 (en) * 1977-07-29 1979-02-07 International Business Machines Corporation Hot roll fuser for a xerographic copier
US4154575A (en) * 1977-08-22 1979-05-15 International Business Machines Corporation Hot roll fuser roll closure apparatus
US4341458A (en) * 1979-10-26 1982-07-27 Hoechst Aktiengesellschaft Thermal pressure fixing device
US4473290A (en) * 1981-04-13 1984-09-25 Minolta Camera Kabushiki Kaisha Toner image fixing device
US4752801A (en) * 1986-04-22 1988-06-21 Alps Electric Co., Ltd. Electrophotographic printer having openable discharge port formed by displacable fuser roller
US4769187A (en) * 1987-09-11 1988-09-06 The Marley Cooling Tower Company Drift eliminator support, drainboard and seal unit for water cooling towers
US4875611A (en) * 1987-12-10 1989-10-24 Xerox Corporation Roll media feed roll system
US20090232566A1 (en) * 2008-03-11 2009-09-17 Brother Kogyo Kabushiki Kaisha Image Forming Apparatus

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1830120A (en) * 1931-11-03 And one-half to lewis m
US3093284A (en) * 1959-05-11 1963-06-11 Minnesota Mining & Mfg Differential capstan assembly
US3254820A (en) * 1964-06-15 1966-06-07 Du Pont Shock absorbing system for yarn delivery apparatus
US3330458A (en) * 1965-05-17 1967-07-11 Quik Chek Electronics And Phot Removable pressure roller mechanism
US3363518A (en) * 1965-12-15 1968-01-16 Mathew G. Boissevain Hydraulically damped air cylinder
US3449548A (en) * 1966-12-30 1969-06-10 Xerox Corp Fusing device
US3452181A (en) * 1967-12-27 1969-06-24 Eastman Kodak Co Roll fusing device for xerographic material
US3754819A (en) * 1971-12-30 1973-08-28 Xerox Corp Apparatus for placing rollers in contact in a pressure fuser assembly

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3197614A (en) * 1961-08-31 1965-07-27 Dick Co Ab Fuser unit for electronic printing machine

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1830120A (en) * 1931-11-03 And one-half to lewis m
US3093284A (en) * 1959-05-11 1963-06-11 Minnesota Mining & Mfg Differential capstan assembly
US3254820A (en) * 1964-06-15 1966-06-07 Du Pont Shock absorbing system for yarn delivery apparatus
US3330458A (en) * 1965-05-17 1967-07-11 Quik Chek Electronics And Phot Removable pressure roller mechanism
US3363518A (en) * 1965-12-15 1968-01-16 Mathew G. Boissevain Hydraulically damped air cylinder
US3449548A (en) * 1966-12-30 1969-06-10 Xerox Corp Fusing device
US3452181A (en) * 1967-12-27 1969-06-24 Eastman Kodak Co Roll fusing device for xerographic material
US3754819A (en) * 1971-12-30 1973-08-28 Xerox Corp Apparatus for placing rollers in contact in a pressure fuser assembly

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3907493A (en) * 1974-07-11 1975-09-23 Xerox Corp Visco-elastic dampener mechanism for fuser assembly
US4110068A (en) * 1977-02-22 1978-08-29 International Business Machines Corporation Hot roller fuser having manually operable jam clearance mechanism
EP0000632A1 (en) * 1977-07-29 1979-02-07 International Business Machines Corporation Hot roll fuser for a xerographic copier
US4154575A (en) * 1977-08-22 1979-05-15 International Business Machines Corporation Hot roll fuser roll closure apparatus
US4341458A (en) * 1979-10-26 1982-07-27 Hoechst Aktiengesellschaft Thermal pressure fixing device
US4473290A (en) * 1981-04-13 1984-09-25 Minolta Camera Kabushiki Kaisha Toner image fixing device
US4752801A (en) * 1986-04-22 1988-06-21 Alps Electric Co., Ltd. Electrophotographic printer having openable discharge port formed by displacable fuser roller
US4769187A (en) * 1987-09-11 1988-09-06 The Marley Cooling Tower Company Drift eliminator support, drainboard and seal unit for water cooling towers
US4875611A (en) * 1987-12-10 1989-10-24 Xerox Corporation Roll media feed roll system
US20090232566A1 (en) * 2008-03-11 2009-09-17 Brother Kogyo Kabushiki Kaisha Image Forming Apparatus
US8027626B2 (en) * 2008-03-11 2011-09-27 Brother Kogyo Kabushiki Kaisha Image forming apparatus

Also Published As

Publication number Publication date
FR2222681A1 (xx) 1974-10-18
GB1424307A (en) 1976-02-11
NL7403874A (xx) 1974-09-24
CA1020218A (en) 1977-11-01
FR2222681B1 (xx) 1977-03-04

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