US3707328A

US3707328A - Sheet guide apparatus

Info

Publication number: US3707328A
Application number: US77669A
Authority: US
Inventors: Richard C Robertson
Original assignee: Multigraphics Inc
Current assignee: AB Dick Co
Priority date: 1970-10-02
Filing date: 1970-10-02
Publication date: 1972-12-26
Anticipated expiration: 1989-12-26

Abstract

A guide arrangement for guiding sheet material through a developer unit over and in contact with a roller, the surface of which is wetted with a liquid developer solution, includes a plurality of fine, filament-like guide wires strung taut across the roller in the direction of movement of the sheet material. The wires prevent the sheet material from becoming wrapped about the roller member.

Description

United States Patent [151 3,707,328 Robertson [451 Dec. 26, 1972 s41 SHEET GUIDE APPARATUS 3,386,730 6/1968 Hyosaka "ass/110 x [721 fi M FOREIGN PATENTS 0R APPLICATIONS rospect,

1 4 19 B [73] Assignee: Addressograph-Multigraph Cor- 86 l 2/ 61 Great mam 355,110 poration, Mount Prospect, 11]. primary Examiner lohn Oran [22] Filed: Oct. 2, 1970 Assistant Examiner-Alan A. Mathews At 1 .G ldt 211 App]. No.: 77,669 L S em [57] ABSTRACT [52] U.S.C1 ..355/106, 355/110, 95/94 R A guide arrangement for guiding sheet material through a developer i overand in Contact a [5 1 0 55/ roller, the surface of which is wetted with a liquid 355/64 95/89 94 R developer solution, includes a plurality of fine, fila- 5 t ment-like guide wires strung taut across the roller in 6] Re erences cued the direction of movement of the sheet material. The UNITED STATES PATENTS wires prevent the sheet material from becoming wrapped about the roller member. 3,484,168 12/1969 Toby ..355/ll0X 1,900,878 3/1933 Hopkins ..355/64 2 Claims, 3 Drawing Figures BACKGROUND OF THE INVENTION This invention relates generally to direct contact type copying machines including developer units wherein copy sheets have applied thereto, by means of a roller member, a quantity of developer liquid, and more particularly to means for guiding the copy sheets safely through the developer unit.

In direct contact copy machines, such as, for example, of the type shown and described in U.S. Pat. No. 3,484,168, assigned to the same assignee, wherein a superimposed copy sheet and original tracing are exposed and subsequently separated, and the copy sheet continues to be transported through a developer unit whereat a liquid developer solution is applied to the copy sheet as the latter is carried over a rotating applicator roller, there exists the possibility that the copy sheet, rather than merely passing over the roller, will adhere to the wetted roller surface and become wrapped thereabout. Also, if the original and copy sheet are not separated after passing through the exposure station, there is a possibility that the original will become wrapped about the liquid applicator roller. If the above occurs, the copy sheet and original could be damaged. Also, it becomes a difflcult and time consuming matter to easily release the wrapped sheets from the roller.

SUMMARY OF THE INVENTION paratus of the present invention includes a plurality of extremely fine, filament-like guide wires having a diameter of 0.004 inches or less, preferably about 0.002 inches, strung taut across the wetted applicator roller between the entrance and exit of the developer unit in a copying machine in contact with the surface of said roller. The wires are in spaced relation to each other along the axis of the roller. Each of the guide wires is tensioned at least at one end so that the rotational movement of the applicator roller is impeded minimally by the wires and so the wires are able to ac-.

commodate any irregularities in the surface of the roller without breaking. The wetted surface of the roller minimizes the friction between the wires and the roller surface.

Copy sheets entering the developer unit are guided along the wires over the surface of the developer applicator roller for development and are prevented by the wires from'becoming wrapped about the roller. The wires provide little, if any, interference with the developing process.

DESCRIPTION OF THE DRAWINGS A better understanding of the present invention and its organization and construction may be had by referring to the description below in conjunction with the accompanying drawings, wherein:

FIG. 1 is a fragmentary, sectional view of a copying machine including a developer arrangement employing a liquid. applicator roller and including sheet guide apparatus according to the invention;

FIG. 2 is an enlarged, fragmentary view of the developer arrangement of the copying machine of FIG. 1 illustrating in greater detail the sheet guide apparatus of the invention; and

' FIG. 3 is a fragmentary, plan view of the developer apparatus of FIG. 2 taken along the line 33.

DETAILED DESCRIPTION Referring now to FIG. 1 of the drawings there is illustrated therein an'automatic copying machine 10 similar to the type shown and described in U.S. Pat. No. 3,484,168, embodying the features of the present invention.

The copying machine 10 includes a rotating transparent drum 12 containing a light source in the form of a lamp 14 to which a superimposed original 16 and copy sheet 18 are fed from feed board 20 along a path 22 beneath guide member 23. The superimposed copy sheet and original are fed past the light source 14 to expose the copy sheet through the cooperation of the rotating drum 12 and a flexible guiding assembly, indicated generally as 24, serving to hold the superimposed sheets in engagement with drum 12 through a portion of the path. The flexible guiding assembly 24 includes a plurality of laterally spaced flexible, endless belts 26 supported by transparent drum l2 and by a plurality of

rollers

28, 30, 32, 34 and 36. The superimposed original and copy sheet are nipped between the rotating drum 12 and the endless belts 26 and rotate with the drum past the light source 14 where the copy is exposed by light passing through transparent or translucent areas of the original.

After exposure of the copy sheet 18, the superimposed original and copy sheet enter the separating sta tion 38 where they are separated from each other by a pair of vacuum chests 40, 42, each including a perforated plate respectively adjacent the original and copy sheet. The force provided by the vacuum chest 40 separates the original from the copy sheet and causes it to be moved into engagement with a guide 44, serving to channel the original between a pair of original delivery rollers to a tray (not shown) disposed at the front of the machine.

The vacuum chest 42 holds the copy sheet in engagement with the endless belts 26 and the sheet is moved between a guide roller 50 and belts 26 carried along roller 36 toward a curved guiding structure 52. From there the sheet is carried between guide plate 54 and guide plate 57 forming an entrance 55 to the developer unit 56. The exposed copy sheet 18 is passed through entrance 55 of the developer unit into the nip 59 of an applicator roller 58 and a pressure roller 60, where it is wetted with a developer liquid contained in a tray 62, which liquid is applied to the surface of the applicator roller 58 by means of a fountain roller 64.

The copy sheet 18 is guided from the developer unit 56 by upper guide plate 66 and guide comb -68, forming exit 70 of the developer unit, through a pair of copy

sheet delivery rollers

72, 74, and along a guide 76 to the copy receiving tray 78 disposed at the front of the copy machine. I

On some occasions during the developing of the copy sheets passing through developer unit 56, a copy sheet will adhere to the wetted applicator roller 58. When the latter occurs the copy sheet b'ecomes wrapped about the roller 58 and continues'to rotate thereabout indefinitely. This wrapping of the copy sheet about the roller 58 could damage the copy sheet, and make it impossible to process subsequent copies through the developer unit until the sheet is removed. Furthermore, it is difficult and time consuming to free the wrapped copy sheet from the roller. Y

In, addition to the above, occasionally an original document fails to separate from a copy sheet in the separator station 38. When this happens both the original and copy sheet are carried into the developer unit. Since the thickness of the two sheets is greater than the copy sheet alone, and since the original document is usually of a relatively light weight and rather flimsy, as in the case of translucent tracings, the original document which is delivered to the developer unit in contacting relation with the applicator roller 58, adheres to the wetted roller surface and .becomes wrapped about the roller. The latter not only presents the problem of having to dismantle the machine to free the wrapped original from the roller, but may result in the destruction of an original of which there may only be a single copy. a To prevent the above situations from occurring, there has been provided in the developer unit 56 of the copying machine 10, a guide arrangement 80, best seen in FIGS. 2 and 3, v

. The guide arrangement 80 includes a plurality of extremely fine, filament-like wires 82, each having a diameter less-than 0.004 inches and preferably about The developer unit 56' of the copying machine described heretofore includes a metering system (not shown) for regulating the amount of developer liquid applied to a copy sheet passing between the applicator and

pressure rollers

58 and 60, respectively. In fact, the amount of developer liquid applied by the applicator roller 58 is less than 3.0 grams per square meter and preferably between 0.5 and 1.0 grams. A more complete description of the construction and operation of the metering system maybe had by referring to copending Pat. application, Ser. No. 831,399 filed June herein is not restricted to a metallic member, but refers forces applied thereagainst by the action of the pressure and applicator rollers, and the moving sheet material.

The guide wires 82 positively prevent a copy sheet or original tracing which might not have been separated, from wrapping about the wetted applicator roller. The wires guide the sheet across the applicator roller 58 and provide little, if any, interference with the development of the copy sheet.

9,1969, which is a continuation-impart application of earlier filed-US. patent application, Ser. No. 606,332, filed Dec. 30,1966. Y

Becauseso little developer liquid is applied to a-copy sheet in the copying machine l0,.one would predict that the guide wires used to guide the-copy sheet safely through the developer zone, would leave striations or marks on the developed copy sheetafter development. Surprisingly, this does not occur. It is believed that the combination of the fine, filament-like wires and the use of developer liquid of a proper consistency compensates for any tendency to leave striations on the developed sheet. As the copy sheet passes through the developer station between applicator and

pressure rollers

58, 60, any striations formed by the guide wires quickly disappear due to the flow of developer liquid thereinto. Upon exiting from the machine, the striations are not evident, and the copy sheet is uniformly developed.

The particular mounting arrangement for the guide wires 82 shown in FIGS. 1-3 of the drawings is illustrated in FIG. 2. One end 84 of each of the guide wires is attached to a mounting post 86 which can be affixed to an existing wall or the like structure of the developer unit. The other end 88 of the wire 82 is attached to a resilient member, herein taking the'form of a coiled spring 90 which in turn is connected to a mounting bracket 92, also affixed to an existing structure in the developer unit. The spring 90 provides the tension required for the wire 82 across applicator roller 58, as well as being a safety release to prevent the wire from snapping due to excessive forces applied thereagainst.

The guide wire arrangement according to the invention is a positive but simple means to prevent copy sheets and/or original tracings from becoming wrapped about the liquid applicator roller in a copying machine of thetype described. The guide arrangement is very effective and needs little, if any, maintenance. In the event a wire of the guide arrangement should require replacement, it is a simple matter to release the wire from its mountings and affix a new wire in its place.

copy of an original document on a copy sheet, including an exposure station whereat a superimposed original and copy sheet are illuminated to create an image of the former on the latter, a separating station whereat the original and copy sheet are separated, and a developing station including a developer unit comprising an entrance and an exit and having therebetween an applicator roller, the surface of which is wetted with a liquid developer solution for application to the surface of a copy sheet transported thereover in contact therewith, and

a pressure roller mounted in driving engagement with said applicator roller, sheet guiding means for guiding sheet material in eluding said copy sheet and original documents which have failed to be separated from said copy sheet, safely over said applicator roller while preventing the wrapping of said sheet material about said wetted applicator roller, said sheet guiding means including a plurality of fine guide wires strung taut between the entrance and the exit of said developer unit over and in contact with said roller member and between said applicator and pressure rollers, said wires further being spaced from each other axially along said applicator roller over the length thereof so as to accommodate sheets of varying widths, wherein 'each of said guide wires is of a diameter of less than 0.004 inches.

2. In a direct contact copying machine for making a copy of an original document on a copy sheet, including an exposure station whereat a superimposed original and copy sheet are illuminated to create an image of the original on the copy sheet, and a developing station including a liquid developer unit comprising an entrance and an exit through which said copy sheet is passed for development, having a supply of liquid developer solution, an applicator roller for use in applying a predetermined amount of developer liquid to said copy sheet passing through said unit, and metering means for metering a predetermined quantity of developer liquid from said supply to said applicator roller, said roller applying less than 3.0 grams per square meter of liquid to said copy sheet, wherein the improvement comprises sheet guiding means for guiding the original document and the copy sheet safely through said developer unit in contacting relation with said applicator roller while preventing the wrapping of either or both of said document and copy sheet about said roller, said sheet guiding means including a plurality of fine, filament-like guide members extending between the entrance and exit of said developer unit, over and in contact with said roller member, said guide members comprising wires, each having a diameter lessthan 0.004 inches, strung taut between the entrance and the exit of said developer unit, wherein each said wire is held at one end by a spring member to provide a tension to said wire while avoiding breakage thereof due to forces applied thereagainst.

Claims

1. In a direct contact copying machine for making a copy of an original document on a copy sheet, including an exposure station whereat a superimposed original and copy sheet are illuminated to create an image of the former on the latter, a separating station whereat the original and copy sheet are separated, and a developing station including a developer unit comprising an entrance and an exit and having therebetween an applicator roller, the surface of which is wetted with a liquid developer solution for application to the surface of a copy sheet transported thereover in contact therewith, and a pressure roller mounted in driving engagement with said applicator roller, sheet guiding means for guiding sheet material including said copy sheet and original documents which have failed to be separated from said copy sheet, safely over said applicator roller while preventing the wrapping of said sheet material about said wetted applicator roller, said sheet guiding means including a plurality of fine guide wires strung taut between the entrance and the exit of said developer unit over and in contact with said roller member and between said applicator and pressure rollers, said wires further being spaced from each other axially along said applicator roller over the length thereof so as to accommodate sheets of varying widths, wherein each of said guide wires is of a diameter of less than 0.004 inches.

2. In a direct contact copying machine for making a copy of an original document on a copy sheet, including an exposure station whereat a superimposed original and copy sheet are illuminated to create an image of the original on the copy sheet, and a developing station including a liquid developer unit comprising an entrance and an exit through which said copy sheet is passed for development, having a supply of liquid developer solution, an applicator roller for use in applying a predetermined amount of developer liquid to said copy sheet passing through said unit, and metering means for metering a predetermined quantity of developer liquid from said supply to said applicator roller, said roller applying less than 3.0 grams per square meter of liquid to said copy sheet, wherein the improvement comprises sheet guiding means for guiding the original document and the copy sheet safely through said developer unit in contacting relation with said appLicator roller while preventing the wrapping of either or both of said document and copy sheet about said roller, said sheet guiding means including a plurality of fine, filament-like guide members extending between the entrance and exit of said developer unit, over and in contact with said roller member, said guide members comprising wires, each having a diameter less than 0.004 inches, strung taut between the entrance and the exit of said developer unit, wherein each said wire is held at one end by a spring member to provide a tension to said wire while avoiding breakage thereof due to forces applied thereagainst.