US3847385A

US3847385A - Sheet container

Info

Publication number: US3847385A
Application number: US00306270A
Authority: US
Inventors: F Wieloch
Original assignee: Xerox Corp
Current assignee: Xerox Corp
Priority date: 1972-11-13
Filing date: 1972-11-13
Publication date: 1974-11-12
Anticipated expiration: 1991-11-12
Also published as: CA991208A; NL7315273A

Abstract

A container in which a stack of sheet material is stored for the subsequent advancement therefrom. The container includes a base plate having a flexible sheet with a portion of the upper surface thereof adapted to engage the under surface of the advancing sheet. The foregoing abstract is neither intended to define the invention disclosed in the specification, nor is it intended to be limiting as to the scope of the invention in any way.

Description

O United States Patent 11 1 1111 3,847,385

Wifilllch Nov. 12, i974 i 1 SHEET CONTAINER Primarv Exanziner--Jz1n1cs B. Marbcrt 75 Inventor. Francis Wreloch P f ld, N.Y. 1 J en 1e Assistan! Examiner-James W. Miller [73] ASS gHEe XEI'OX P fi Stamford, Attorney, Agent, or Firm-H. Fleisher; C. A. Green; J.

Conn, J. Rulabate [22] Filed: Nov. 13, 1972 STR CT 57 AB A [21] Appl. No.: 306,270 1 A contamer in which a stack of shect material is stored for the subsequent advancement therefrom. Cl 271/203 The container includes a base plate having 11 flexible [51] Illt. heet with a portion of the upper surface thereof Field of Search i l adapted to engage the under urface 0f the advancing 271/121-125, 22, 208; 206/57 R Sheet The foregoing abstract is neither intended to define [56] References the invention disclosed in the specification, nor is it UNITED STATES PATENTS intended to be limiting as to the scope of the invention 3,237,935 3/1966 Becker et al 271/148 in any way. 7 3,522,878 8/1970 Rosenburg 206/57 R 3,640,524 2 1972 Fredrickson 271/121 5 Claims, 3 Drawmg Figures PATENTEDHUV 12 I974 3841.385 SHEEI 20$ 2 SHEET CONTAINER BACKGROUND OF THE INVENTION This invention relates generally to. a container for supporting a stack of sheet material which is to be dispensed therefrom, and more particularly, to a container adapted to facilitate seriatim feeding of succes sive uppermost sheets from the stack of sheet material disposed therein.

Typical electrophotographic printing machines utilized in business offices are provided with cut sheets of support material. The sheets are used as an imaging receiving member in the printing machine. Although paper is the most commonly used sheet material, certain non-fibrous plastic sheets characterized generally by having a high surface gloss and a smooth surface are increasingly employed. These non-fibrous sheets are frequently more durable than paper and, when transparent, have great utility as transparencies, i.e., a con ventional projector may project images therefrom onto a screen.

Generally, the sheet material is of a preselected size and advances through the printing machine, one sheet at a time, for suitable processing therein. Inasmuch as copies may be made at high speeds, it is advantageous to stack a pile of sheets in the printing machine feeding mechanism which advances automatically one sheet at a time therefrom. The sheets are advanced until the stack thereof is depleted, whereupon the operator refills the machine with a new stack of sheets. However, when non-fibrous sheet material is substituted for paper operational difficulties frequently occur. For example, in feeding successive non-fibrous sheets, it is found that the top sheet often causes creep or advancement of the sheetsimmediately therebelow. This results in misfeeds and jams within the machine, thereby greatly increasing the amount of wasted sheets and the ensuingcost of the operation. In addition thereto machine downtime, i.e., the time necessary to clear the machine of sheet jams, is substantially greater than if misfeeds or jams did not occur. It appears that jams and misfeeds are caused by the relatively high sliding friction between successive non-fibrous sheets and, also, by the electrically insulating nature of the nonfibrous sheets which permits an accumulation of electrostatic charges thereon. Electrostatically charged sheets attract one another making separation thereof more difficult.

The utilization of non-fibrous sheets as transparencies in electrophotographic printing machines becomes more significant with the advent of multi-color machines. In a multi-color electrophotographic printing machine, it is highly desirable to have the capability of creating multicolortransparencies. Transparencies of this type are frequently required for display purposes, i.e., via projection onto screens for seminars or business meetings. Hence, there is continuing need for more trouble free feeding and processing of nonfibrous material, particularly for multi-color electrophotographic printing machines.

Moreover, it is desirable to pre-package the stack of transparent sheets for shipping to minimize handling maintaining the sheets substantially free from dirt and finger prints. In addition thereto, a prepackaged stack of transparencies is automatically keyed to the proper orientation for use in the printing machine, i.e., the preferred sheet side has the toner powder images deposited thereon and coalesced thereto.

Accordingly, it isa primary object of the present invention to improve the container storing a stack of sheet material therein so that successive feeding of sheets therefrom isfacilitated.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS Other objects and advantages of the present invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which: r

FIG. 1 is a schematic view of an electrophotographic printing machine incorporating the present invention therein;

FIG. 2 is a perspective view of a container used in the FIG. 1 printing machine for storing sheet material therein; and

FIG. 3-is an elevational view of the FIG. 2 container cooperating with the FIG. 1 printing machine feeding mechanism for the advancement of sheet material therefrom.

While the present invention will be described in connection with a preferred embodiment thereof, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION For a general understanding of the disclosed electrophotographic printing machine in which the present invention may be incorporated, continued reference is had to the drawings wherein like reference numerals have been used throughout to designate like elements. FIG. 1 schematically illustrates the various components of a printing machine for producing multi-color copies from a colored original. Although the container of the present invention is particularly well adapted for use in an electrophotographic printing machine, it should be come evident from the following discussion that it is equally well suited for use in a wide variety of printing machines and is not necessarily limited in its application to the particular embodiment shown herein.

The printing machine illustrated in FIG. 1 employs a photoconductive member having a rotatably mounted drum 10 with a photoconductive surface 12 thereon. Basically, drum 10 is rotated in the direction of arrow 14 to pass sequentially. through a series of processing stations A through E, inclusive. Drum 10 and other machine operating mechanisms are driven at a predetermined speed relative to each other from a common drive motor (not shown). The various machine operations are coordinated to produce the proper sequence of events at the processing stations.

' Drum initially moves photoconductive surface 12 through charging station A. Charging station A has positioned thereat a corona generating device indicated generally at 16. Corona generating device 16 extends in a generally transverse direction across photoconductive surface 12. In this manner, corona generator device 16 is adapted to charge photoconductive surface 12 to a relative high substantially uniform potential. Preferably, corona generator device 16 is of a type described in U.S. Pat. No. 2,778,946 issued to Mayo in 1957.

Drum 10 is next rotated to exposure station B where photoconductive surface 12 is exposed to a color filtered light image of the original document. Exposure station B includes a moving lens system, generally designated by the reference numeral 18, and a color filter mechanism, shown generally at 20. A suitable moving lens system is disclosed in U. S. Pat. No. 3,062,108 issued to Mayo in 1962. As shown in FIG. 1, an original document 22, such as a sheet of paper, book or the like,

' is placed face down upon transparent viewing platen 24. Lamp assembly 26 and lens system 18 are moved in a timed relation with drum 10 to scan successive incremental areas of original document 22 disposed upon platen 24. Thisproduces a flowing light image of original document 22 onphotoconductive surface 12. During exposure, filter mechanism interposes selected color filters into the optical light path of lens 18. The color filter operations on the light rays passing through the lens to record an electrostatic latent image on photoconductive surface -12 corresponding to preselected special region of the electromagnetic spectrum, hereinafter referred to as a single colorelectrostatic latent image.

The single electrostatic latent image recorded on photoconductive surface 12, is next transported to development station C. Development station C includes thereat three individual developer units, generally indicated by the

reference numerals

28, 30 and 32, respectively. A suitable development station employing a plurality of developer units is disclosed in copending application Ser. No. 255,259 filed in 1972. Preferably, the developer units are all of the type generally referred to in the art as magnetic brush developer units. Typical magnetic brush systems utilize a magnetizable developer mix which includes carrier granules and toner particles. The developer mix is continually brought through a directional flux field to form a brush thereof. The electrostatic latent image recorded on photoconductive surface 12 is'developed by bringing the brush of developer mix into contact therewith. Each of the respective developer units contain discretely colored toner pqrticles corresponding to the complement of the spectral region of the wavelength of light transmitted through filter 20, e.g., a green filtered electrostatic latent image is made visible by depositing green absorbing magenta toner particles therein, blue and red latent images are developed with yellow and cyan toner particles, respectively.

Drum 10 is next rotated to transfer station D where the toner powder image adhering electrostatically to photoconductive surface 12 is transferred to a sheet offinal support material 34. Final support material 34 may be, amongst others, plain paper. However, the container of the present invention is particularly adapted for use with a non-fibrous sheet of support material.

A preferred polymeric non-fibrous sheet of support material is polysulfone thermoplastic available in sheets of approximately 4 mils thickness under the trademark Rowlex from Rowland Products, Inc., Kensington, Conn. This material, in sheet form, is very transparent and may be processed satisfactorily to receive thereon a high quality coloredimage corresponding to the original document to be reproduced. Another polymeric non-fibrous material for use herein is polyethylene terephthalate polyester transparent sheet material available under the trademark Mylar from the E. l. DuPont De Nemours Co., and may be obtained in a wide range of thicknesses. Many transparent, as well as opaque polymeric materials are available in the art which may be formed into films to receive multicolor images thereon. Any suitable high temperature coated film formable polymeric material may be used.

Bias transfer roll, shown generally at 36, recirculates support material 34 and is electrically biased to a potential of sufficient magnitude and polarity to attract electrostatically toner particles from the latent image recorded on photoconductive surface 12 to support material 34. A suitable electrically biased transfer roll is described in U.S. Pat. No. 3,612,677 issued to Langdon in 1971. Transfer roll 36 rotates in synchronism with photoconductive surface 12. Inasmuch as support material 34 is secured releasably thereon for movement in a recirculating path therewith, successive toner powder images may be transferred thereto in superimposed registration. Support material 34 is advanced from a stack thereof disposed in a container, indicated generally at 38. Feed roll 40 in operative communication with retard roll 42 (FIG. 3) advances and separates the uppermost sheet from the stack disposed within container 38. Container 38 will be described hereinafter in detail in association with FIGJ2. The cooperative relationship between feed roll 40, retard roll 42 and the stack of sheet material disposed within container 38 will be discussed hereinafter, in detail, with reference to FIG. 3. The advancing sheet moves into chute 44 which directs the sheet into the'nip of register rolls 46. Thereafter, gripper fingers 48 mounted on transfer roll 36 secure releasably thereon support material 34 for movement in a recirculating path. With continued reference to FIG. 1, sheet 34 is stripped from transfer roll 36 and advanced with the thermoplastic coated side down, on endless belt conveyor 50 to fixing station E where a fuser, indicated generally at 52, coalesces the transferred powder image to sheet 34. One type of a suitable fuser is described in U.S. Pat. No. 3,498,592 issued to Moser et al. in 1970. After the fixing process, sheet 34 is advanced by

endless belt conveyors

54 and 56 to catch tray 58 for subsequent removal therefrom by an operator.

Although a preponderance of the toner material is transferred to the support material, invariably some residual toner particles are left behind on photoconductive surface 12 after the transfer of the powder image to support material 34. This residual toner is removed from the drum as it moves through cleaning station F. Here the residual toner is first brought under the influence -of a cleaning corona generating device (not shown) adapted to neutralize the electrostatic charge remaining on the material. The neutralized toner is then mechanically cleaned from photoconductive surface 12 by a rotatably mounted fibrous brush 58. A suitable brush cleaning device is described in U.S. Pat. No. 3,590,412 issued to Gerbasi in 1971. Rotatably mounted brush 58 is positioned at cleaning station F and maintained in contact with photoconductive surface 12. In this manner, residual toner particles remaining on photoconductive surface 12 after each transfer operation are removed therefrom.

It is believed that the foregoing description is sufficient for purposes of the present application to show the general operation of an electrophotographic printing machine embodying the teachings of the present invention. 1 v

Referring now to the specific subject matter of the present invention illustrated more clearly in FIGS. 2 and 3, container 38 storing a stack of support material therein will be discussed hereinafter, in detail. Turning tion member, indicated generally at 72 includes a pair of opposed side members 74 and a rear member 76.

Each side member 74 is affixed to one of the side edge portions of base plate 62 by suitable means, e.g. adhesive. In this way, side members 74 definea pair of op posed spacedgenerally planar surfaces extending substantially in a direction normal to base plate 62. Stack 64 is disposed onbase plate 62 such that at least one of the side edge portions thereof engage side members 74. This aligns the'side edges of each sheet of support material 34 in registration with one another. Similarly, rear member 76 is attached to base plate 62 by suitable means, e.g., an adhesive, defining a generally planar surface extending substantially in a direction normal to side members 74 and base plate 62. Rear member 76 is adapted to engage the trailing edge of stack 64 so as to align each sheet of support material 34 in registration with one another. Thus, it is evident that the combination of side member 74 and rear member 76, cooperating with one another, insures that both the side edges and leading and trailing edges of stack 64 are aligned such that each sheet of support material 34 is in registration with one another. A top plate 78 is attached to the upper edge portions of side members 74 and rear member 76. Top plate 78 in conjunction with base plate 62 defines a cavity for storing stack 64. As depicted in FIG. 2, top plate 78 has a notch 80 in the region of the leading marginal edge portion thereof affording access to the uppermost sheet of stack 64. This enables successive uppermost sheets 34 to be withdrawn from the cavity defined by top plate 78 and base plate 62. Flexible sheet 66 is, preferably, made from a fibrous material which may be conductive to ground static charge thereon. One suitable flexible sheet material is plain paper amongstothers. Flexible sheets 66 is adapted to cooperate with non-fibrous support material 34 to provide sequential feeding of single sheets preventing machine jams and insuring proper operation of theelectrophotographic printing machine depicted in FIG. 1.

While the invention has been described in connecthe side and rear members attached thereto, one skilled in the art will appreciate that the invention is not necessarily so limited and that the container may be made from sheet metal or plastic in which the base plate side members and rear member are formed from a single sheet wherein the side and rear member are bent in an upwardly direction from the base plate.

Referring now to FIG. 3, container 38 is depicted therein in cooperation with feed roll 40 and retard roll 42. Notched portion 80 of top plate 78 enables feed roll 40 to have access to the upper surface of the uppermost sheet 34 of stack 64 disposed on base plate 62. Feed roll 40 is adapted to rotate in the direction of arrow 82. Flexible sheet 66 is bent into an arcuate configuration and interposed between retard roll 42 and feed roll 40. As feed roll 40 rotates in the direction of arrow 82, it advances the uppermost sheet into the nip between retard roll 42 and feed roll 40 over flexible sheet 66. The utilizationof fibrous flexible sheet 66 prevents multiple sheet feeding and permits only a single sheet to pass over flexible sheet 66 between feed roll 40 and retard roll 42.

From the foregoing, it is apparent that the container of the present invention cooperates with the feeding most sheets from a stack of sheet material disposed in the container. In particular, the container is adapted to feed successive non-fibrous sheets. Hence, the apparatus of the present invention facilitates the automatic sheet feeding of successive non-fibrous sheets of support material adapted to be utilized in an electrophotographic printing machine for the formationof colored transparencies.

It is, therefore, evident that there as been provided in accordance with the present invention, a container cooperating with a sheet feeding mechanism for preventing multiple feeding of sheets from a stack that fully satisfies the objects, aims and advantages set forth above. While this invention has been described in conjunction with a specific embodiment thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all alternatives, modifications andfvariations that fall within the spirit and broad scope of the appended claims.

What is claimed is:

1. An apparatus for separating and feeding successive single sheets from a stack of sheet material, including:

a rotary driven feed roll, said feed roll being adapted to engage the upper surface of successive uppermostsheets in the stack of sheet material;

a retard roll cooperating with said feed roll for seriatim feeding of successive uppermost sheets from the stack;

a base plate defining a generally planar surface for supporting the stack; and e a flexible sheet having one marginal edge portion thereof secured to the leading edge portion of said base plate, said flexible sheet extending in a substantially outwardly direction beyond said base plate and being interposed between said feed roll and said retard roll such that a portion of the upper surface thereof engages the undersurface of successive uppermost sheets advancing from the stack disposed on said base plate.

2. An apparatus as recited in claim 1, further including a registration member extending substantially in an upwardly direction from base plate, said registration member having a first portion defining a generally planar surface engaging one side edge portion of the stack and a second portion defining a generally planar surface extending substantially in a direction normal to the first portion thereof engaging the trailing edge portion of the stack to substantially align the sheets thereof in registration with one another.

3. An apparatus as recited in claim 2, wherein:

the first portion of said registration member includes a side member defining a generally planar surface extending substantially in a direction normal to said base plate and being affixed thereto in the region of one side marginal edge portion thereof; and

the second portion of said registration member includes a rear member defining a generally planar surface extending substantially in a direction normal to said side member and said base plate, said rear member being attached to said base plate in the region in the trailing marginal edge portion thereof.

4. An apparatus as recited in claim 2, further including a top plate attached to said registration member and having a generally planar surface extending substantially in a direction parallel to said base plate defining a cavity therebetween for storing the stack therein, said top plate having a notch in the region of the leading marginal portion thereof affording said feed roll access to the upper surface of the uppermost sheet of the stack permitting the advancement thereof from the cavity. i

5. An apparatus forseparating and feeding nonfibrous sheets, as recited in claim 1, wherein said flexible

Claims

1. An apparatus for separating and feeding successive single sheets from a stack of sheet material, including: a rotary driven feed roll, said feed roll being adapted to engage the upper surface of successive uppermost sheets in the stack of sheet material; a retard roll cooperating with said feed roll for seriatim feeding of successive uppermost sheets from the stack; a base plate defining a generally planar surface for supporting the stack; and a flexible sheet having one marginal edge portion thereof secured to the leading edge portion of said base plate, said flexible sheet extending in a substantially outwardly direction beyond said base plate and being interposed between said feed roll and said retard roll such that a portion of the upper surface thereof engages the undersurface of successive uppermost sheets advancing from the stack disposed on said base plate.

3. An apparatus as recited in claim 2, wherein: the first portion of said registration member includes a side member defining a generally planar surface extending substantially in a direction normal to said base plate and being affixed thereto in the region of one side marginal edge portion thereof; and the second portion of said registration member includes a rear member defining a generally planar surface extending substantially in a direction normal to said side member and said base plate, said rear member being attached to said base plate in the region in the trailing marginal edge portion thereof.

4. An apparatus as recited in claim 2, further including a top plate attached to said registration member and having a generally planar surface extending substantially in a direction parallel to said base plate defining a cavity therebetween for storing the stack therein, said top plate having a notch in the region of the leading marginal portion thereof affording said feed roll access to the upper surface of the uppermost sheet of the stack permitting the advancement thereof from the cavity.

5. An apparatus for separating and feeding nonfibrous sheets, as recited in claim 1, wherein said flexible sheet is made from a fibrous material.