US3542361A - Sheet separating apparatus - Google Patents

Description

United States Patent Daniel I). Call Arlington Heights, Illinois 726,796

May 6, 1968 Nov. 24, 1970 Bell & Howell Company Chicago, Illinois a corporation of Illinois lnventor Appl. No. Filed Patented Assignee SHEET SEPARATING APPARATUS 20 Claims, 7 Drawing Figs.

U.S. Cl 271/64 Int. Cl B65h 29/66 Field olSearch 271/64, 63;

[56] References Cited UNITED STATES PATENTS 3,017,179 1/1962 Stuckens 271/64 3,112,926 12/1963 Stuckens 271/64 Primary Examiner-Richard E. Aegerter Attorneys1ack H. Hall and Gerald M. Newman ABSTRACT: Mechanical apparatus for separating superimposed sheets having congruent leading edges. The apparatus includes a separating member pivotably mounted on an axis coincident with a transport roller axis, and having sheet arresting means extending into the transport path of only one of the superimposed sheets.

Patented Nov. 24, 1970 Sheet &\\\\\ \\\\\\\\\W I I] I! 1710672167: Daniel I) Call.

y2 77AMoZq/g 1 SHEETSEPARATING APPARATUS DISCLOSURE This invention relates in general to apparatus for handling sheet material and in particular to apparatus for separating superimposed sheets of paper. More particularly,this invention relates to apparatus for separating two superimposed sheets of paper wherein the leading edges of said sheets are congruent.

in many copying machines, such as those using the diffusion transfer and photographic processes, wherein the contents of an original document sheet is reproduced on a sheet of copy paper, the original document and the copy sheet must be superimposed and fed together into the machine. After several process operations are performed on the superimposed sheets, they are separated and each of the sheets is then directed through different transport paths. The original document sheet may be returned immediately to the operator while the copy sheet is typically directed through at least one additional processing station where the image is developed.

Proper and reliable separation of the original document and the copy sheet is extremely important since a malfunction will direct both of the sheets along the same transport path. If the malfunction directs bothsheets along the original document path, the copy sheet will not be developed. On the other hand, if both sheets are directed to the developing station, the original sheet could be discolored, damaged, or rendered totally unusable. Of course, it is also desirable to achieve reliable sheet separation without the risk of'jamming, which might tear the original document.

In the prior art, separation of the document and copy sheet is accomplished by various types of pneumatic, roller, or pivotable deflectormeans, or by various cam and toggle separating members having-varying degrees of complexity and reliability. One of the major obstacles of the less complex prior art sheet separation'devices is the requirement that the leading edges of the document and copy sheets be offset or staggered, that is, that the leading edge of one of the sheets lead the leading edge of the other sheet through the sheet transport path. The edge of the leading sheet imparts movement to separating element which guides the sheet along a first sheet path, and presents a second guiding surface for guiding the second sheet along a different sheet path, thus effecting sheet separation.

The difficulties attendantoffset leading edges have long been recognized, and this has necessitated a continual user education program. The failure to properly offset the sheets may result in only a partial copy or could result in ruining the document sheet. The problem is compounded since some copying machines require the copy sheet to lead the original document, while in othermachines the document is the leading sheet. In the course of operating a copying machine, even a well-instructed user may occasionally forget to properly offset the sheets thereby resulting in ruined copies and possible damage to a valuable original document.

This invention obviates the above and other related problems by providing a simple mechanical sheet separator which is very reliable and-does not require the sheets to be offset, although the separator of the invention is fully capable of separating superimposed sheets having offset leading edges. This multisepara tion capability substantially reduces the number of unreproduced copies and also reduces damage to original documents caused by carelessly feeding the superim posed sheets into the copying machine.

The sheet separating device of the invention is partially located within the physical confines of one transport roller and operates adjacent the nip formed by the transport roller within which it is located, and an adjacent transport roller. Thus, the sheet separator of the invention occupies a minimal amount of space.

In accordance with the'invention, a pivotable sheet separating member is provided having an axis coincident with the rotational axis of a transport roller. The sheet separating member carries a tang which projects a distance slightly less than the thickness of a sheet of paper, above the surface thereof. This tang is positioned in the transport path of only one of the superimposed sheets, and that sheet rides along a guide surface of thepivotable member until its leading edge engages and is arrested by the tang.

Further transport of the'engaging sheet pivots the separating member which in turn carries the engaged sheet along with it, drawing the leading edge out of the normal path of movement and away from the nonengaged sheet. Further move ment 'of the superimposed sheets by the transport apparatus pivots the sheet separating member through an angle which is sufficient to cause interference between the arrested sheet and a pair of stripper fingers which remove the sheet from the tang The removed sheet is prevented from returning to its original path of movement by a deflecting structure which guides the previously arrested sheet along one path, and the other sheet along a totally different path. After the sheets have been separated and have left the separating member, the latter is returned to its original position.

Accordingly, it is the primary object of this invention to pro vide novel and simple sheet separating means for separating superimposed sheet material.

Another object of this invention is to provide novel mechanical sheet separating means capable of separating superimposed sheets having congruent leading edges.

An additional object of this invention is to provide mechanical sheet separating means comprising a pivotable sheet separating member having a pivoting axis coincident with the axis ofa sheet transport roller.

A further object of this invention is to provide a novel sheet separator which operates on a sheet having a controlled sheet thickness.

It is also an object of this invention to pro ide mechanical sheet separating means which are partially housed between adjacent roller segments of a sheet transport roller.

Other objects of this invention will become apparent from an understanding of the following descrip ion taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a side elevational view of a portion of a copying machine incorporating the sheet separator of the invention,

taken along staggered section line li-1 of FIG. 1.

FIG. 2 is a top plan view ofthe copying machine taken along staggered line 2-2 of FIG. 1.

FIG. 3 is an enlarged three-dimensional perspective view of the sheet separating member of the invention, as viewed from the upper right corner of FIG. 1.

FIG. 4 is an enlarged top plan fragmentary view ofthe sheet separator showing its relationship to a relieved section of the stationary deflector and the stripping fingers.

FIGS. 5,6, and 7 are enlarged elevational views sequentially showing the superimposed sheets and the sheet separating elements in various operational modes.

Referring to FIGS. 1 and 2, wherein a portion of a copying machine in which the invention may be utilized is shown, the machine is seen to include atop wall 10, sidewalls 12 and 14, and support walls 16 and 18. The top wall has an inclined frontal wall 20 which slopes' toward an entrance platen 22. Frontal wall 20 and platen 22 define a sheet entrance opening 24 through which the superimposed sheets are inserted into the copying machine. Support walls 16 and 18 carry a pair of ingress transport rollers 30 and 32 on suitable bearings and the rollers form a nip at 31 for accepting superimposed sheets fed into the machine through opening 24.

Referring to FIG. 1, the superimposed sheets are seen to comprise an original document sheet 42 having a leading edge 46, and a copy sheet 44 having a leadingedge 48. The copy sheet-may have a light sensitive coating on one surface tion are fed into the nip 31 with the leading edges congruent. This arrangement is more natural for a user,and requires less instruction, resulting in fewer operational errors.

The ingress rollers transport the superimposed sheets to an exposing station 50 which comprises a transparent cylinder 54. Cylinder 54- functions as a transport roller and houses a tubular light source 52, and a light shield 56 having a longitudinal opening 58 for directing light from the source toward the superimposed sheets. Roller 54 is positioned above and in nipforming relation to a complementary transport roller 60 which is supported for rotation on a shaft 72 carried in bearings 61 and 68 on walls 16 and 18. Transport roller 60 is split into two ltroller segments, 62 and 64, for reasons to be noted ;;hereinafter.

As the superimposed sheets are driven through the exposing station, the sensitive coating is exposed through the original document, 42, thereby obtaining a latent image on the copy sheet.

Upon leaving the exposing station, the superimposed sheets are separated and directed through different paper paths, the copy sheet being directed downwardly to a developing station. and the original document being returned to the operator through an egress opening 64' provided in the top wall.

In accordance with the invention, separation of the superimposed sheets is provided by a sheet separating member 70 which is pivotably mounted on roller shaft 72 with its pivot axis coincident with the axis of roller 60, and is located in the gap between the roller segments, 62 and 64. The sheet separating member normally assumes the position shown in FIG. 1 under the influence of a biasing spring 74 anchored between an aperture 73 in a tab 76 at the rear of the separating member, and the copying machine frame at 78. A stop 80 is also provided to insure proper positioning of the sheet separating member, and as best seen in FIGS. 1 and 2, the stop comprises a horizontal plate extending from a bracket 83 fastened to the frame by fasteners 85.

As best illustrated in the perspective view in FIG. 3, the sheet separating member has an irregular shape and is fabricated of plastic or like material. The member includes an aperture 84 having a diameter larger than that of shaft 72 on which it is positioned, thereby providing a loose fit which allows member 60 to. be pivoted independent of the shaft rotation. The separating member further includes an inclined guide surface 86 disposed in the normal path of the superimposed sheets for guiding the leading edges thereof, whichmay have a slight curl, toward a tang 88 which extends substantially perpendicularly from the plane of the guide surface. The tang includes sloped sidewalls 90 and 92 for more squarely arresting sheets which'may be skewed.

As best seen in FIGS. 1, 2, and 4, a deflector member 100 is provided in front of the separating member and includes an apex edge 103 between V-shaped sheet guiding surfaces 102 and 104 for guiding the separated sheets along different paths. Surface 102 guides the document sheet upwardly to egress opening 64', while surface 104 prevents the copy sheet from returning to its original path and guides it downwardly to a developing station, ,not shown. The deflector also includes a centrally relieved section 106 through the middle of the apex 103 which provides clearance for the forward end of the separating member as it pivots about its axis.

A pair of stripper fingers 108 and 110 are provided on each side of the separating member to insure proper removal of the copy sheet from the arresting tang and to prevent excessive bending thereof.

The dimensions of the tang relative to the sheet being separated are quite critical, since it is important that the tang arrest only one of the superimposed sheets, even though the leading edges thereof are congruent. Arrest of only one sheet is insured by providing the height of the tang substantially equal to or slightly less than the thickness of the copy sheet, which in the illustrated embodiment is the sheet cooperating with the tang. The sheet arrangement of the illustrated embodiment is particularly advantageous since the thickness of the copy sheet can be controlled and is reasonably uniform from one sheet to another, which, as is well known, is not the case with original document sheets which may range in thickness from tissuelike paper to stiff, double-ply sheets. With the tang engaging sheets of uniform thickness, the tang height can be more easily determined. By way of example, with copypaper having a thickness of .004 inches, a tang height of .003 inches is recommended.

Referring now to FIGS. 1, 5, 6, and '7, the operational sequence of the sheet separating member will be shown in detail. In FIG. 1, the superimposed sheets with their leading edges congruent, are seen to be driven into the guide surface 86 of the sheet separating member. The guide surface extends into the path of both leading edges, thus. movement of the sheets to the right causes the separating member to pivot slightly clockwise against the biasing of spring 74. This guide surface is quite desirable should the copy sheet have a slight curl on its leading edge, since this sheet might otherwise slide over and escape the grasp ofthe tang.

As seen in FlG. 5, the separating member has been pivoted clockwise by the copy sheet so that tang 88 is disposed in the path of the leading edge of only one of the superimposed sheets. This sheet is driven into engagement with the tang causing further clockwise movement ofthe pivotable member and simultaneously pulls the arrested sheet out of the normal transport path and downwardly beneath the surface 104 of the deflector, as seen in FIG. 6. At the same time, original document sheet 42 which has not been arrested by the tang, continues along its normal transport path until its leading edge 46 encounters deflector surface 102 which guides it upwardly through the egress slot 64. Thus, just before the copy sheet is released from the tang the apex 103 ofthe deflector protrudes into the separation gap between the sheets to prevent reuniting thereof.

At this point in the separating sequence, the arrested sheet has driven the sheet separator sufficiently so that the sheet is contacted by stripper fingers 108 and 110. Further movement of the sheet and tang, and the resultant interference with the stripper fingers, causes the arrested sheet to be lifted from the separating member, and due to its resilience, the sheet assumes the position shown in dotted lines in FIG. 6 with the leading edge, 48, contacting the lower deflector surface. The deflector thus prevents the copy sheet from returning to its normal path. After the superimposed sheets have been separated, the separator member assumes the position shown in FIG. 7 and does not return to its normal position until the lower sheet has left the separating station. After the sheet has left the station, the separating member is biased back to its normal position by spring 74.

From the foregoing operation wherein the superimposed sheets have congruent leading edges, it may be easily seen that the structure of the invention will also reliably separate superimposed sheets when the leading edge of the lower sheet is offset forward of the leading edge of the original document.

In addition, the separator will also satisfactorily separate superimposed sheets when the leading edge of the upper sheet slightly leads the leading edge of the lower sheet, since in this situation the upper sheet will ride over the tang, and the tang will arrest the lower sheet when it subsequently arrives at the proper position.

It is obvious that upon study by those skilled in the art the disclosed invention may be altered or modified both in physical appearance and construction without departing from its inventive concept.

Iclaim:

1. Apparatus for separating superimposed sheets, comprising: means for transporting said superimposed sheets through a transport path; a pivotably mounted member having sheet arresting means extending into the path of the leading edge of only one of said superimposed sheets; said pivotably mounted member being pivotable through a first angle by said transport means driving the leading edge of said one sheet into contact with said arresting means, thereby causing said leading edge to deviate from said'transport path, and means for preventing said leading edge from returning to said-transport path.

2. The sheet separating apparatus as set forth in claim 1 wherein said pivotably mounted member is pivotable through a second angle, whereby said leading edge is released from said arresting member. 7

3. The sheet separating apparatus as set forth in claim 2 wherein said pivotable member is located adjacent said transport path, and wherein said sheet arresting means comprise a tang protruding from said pivotable member into said transport path.

4. Apparatus for separating superimposed sheets wherein the leading edges of said superimposed sheets are congruent, comprising: means for transporting said superimposed sheets through a transport path; a pivotably mounted member located adjacent said, transport path having a sheet arresting means extending into the the path of said superimposed sheets a distance substantially no greater than the dimensional thickness of the arrested sheet; said transport means driving the leading edge of said one sheet into contact with said arresting means thereby pivoting said arresting means through a first angle and causing said leading edge to deviate from said trans port path and pivoting said arresting means through a second angle to release said leading edge therefrom, and means for preventing said leadingedge from returning to said transport path.

5. The sheet separating apparatus as set forth in claim 4 wherein said pivotably mounted member includes a sheet guiding surface preceding said tang; and further including means normally biasing said pivotable member such that its guiding surface preceding said tang; and further including means normally biasing said pivotable member such that its guiding surface is disposed in said transport path; said transport means driving said leading edges into said guiding surface and imparting pivotal movement to said member thereby positioning said tang in the path of only said one sheet.

6. The sheet separating apparatus as set forth in claim 5 including additionally; stripper means for stripping said leading edge from said tang to prevent excessive deviation thereof from said transport path and excessive bending of said one sheet prior to release from said tang.

7. The sheet separating apparatus as set forth in claim 6 wherein said transport means include a first transport roller having an axis of rotation coincident with the pivot axis of said pivotable member, and a second transport roller in nip-forming relation with said first roller; and wherein said tang normally extends past the peripheral surface of first roller.

8. The sheet separating apparatus as set forth in claim 7 wherein said first transport roller comprises two roller segments, said pivotable member being located intermediate said roller segments.

9. The sheet separating apparatus as set forth in claim 7 wherein said second roller is located substantially vertically above said first rollerfor transporting said superimposed sheets along a substantially horizontal path; said lowermost sheet cooperating with said guiding surface for pivoting said tang into the horizontal path of said lowermost sheet; and wherein said means for preventing said leading edge from returning to said transport path comprise a deflector having surfaces for directing said separated'sheets along different paths.

10. The sheet separating apparatus as set forth in claim 9 wherein said deflector includes an apex edge which protrudes into a gap between theseparated sheets prior to release from said tang, to prevent reuniting of said sheets.

11. Apparatus for separating two superimposed sheets, one of said sheets having a controlled, substantially consistent thickness and the other of said sheets having an uncontrolled thickness, comprising: transport means including first and second transport rollers in nip-forming relation for moving said superimposed sheets along a given path, and a pivotably mounted sheet separating member having an axis coincident with the axis of said first transport roller; said separating member including sheet arresting means extending into said given path for engagement by the leading edge of said sheet having consistent thickness; said engagement pivotably moving said separating member and simultaneously drawing said engaged sheet out of said given path, thereby separating said superimposed sheets.

12. The sheet separating apparatus as set forth in claim 11 wherein said second transport roller is disposed substantially vertically above said first transport roller, and wherein said first transport roller comprises two roller segments; said separating member being disposed between said roller segments with said arresting means extending upwardly from said first roller, beyond the peripheral surface thereof into said given path.

13. The sheet separating apparatus as set forth in claim 12 including additionally: sheet deflector means; guide means on said pivotable member preceding said arresting means, and spring means normally biasing said guide means into the path of said superimposed sheets; said-sheets being driven into said guidemeans causing said member to pivot and presenting said arresting means only in the path of said sheet of constant thickness; and wherein the leading edge of said sheet temporarily engages said arresting means and said deflector means prevents return of said arrested sheet to its original path.

14. The sheet separating apparatus as set forth in claim 13 further including: stripper means for releasing said leading edge from said arresting means and preventing excessive deviation of said sheet from said path, and wherein said deflector means is stationary and includes a deflecting surface for each of said superimposed sheets.

15. in a copying machine in which an original document sheet and a radiation sensitive copy sheet are fed in superimposed relation with the leading edges thereof substantially congruent; and exposure station for exposing said copy sheet to radiation thereby forming a latent image of said original document thereon; and a sheet separating station for separating said exposed copy sheet from said original document sheet, said separating station comprising: sheet transport means for transporting said superimposed document and copy sheets along a given path; a pivotable member having sheet arresting meansin the path of only one said superimposed sheets whereby said sheet transport means will drive said leading edge of said one sheet into said arresting means to pivot said arresting means and thereby causing said sheet to deviate from said transport path; and deflector means preventing return of said deviated sheet to said transport path.

16. The copying machine as set forth in claim 15 wherein said sheet arresting means comprise a tang and wherein said pivotable member includes a guide surface forwardly of and adjacent said tang; andincluding additionally: spring means normally biasing said guide surface into said path of said sheets.

17. The copying machine as set forth in claim 16 wherein said superimposed sheets are orientated with the original document sheet overlying said copy sheet, and wherein said pivotable memberis disposed below the path of said superimposed sheets, said sheet arresting means operating on said copy sheet, drawing it downwardly out of its normal path, and beneath said deflector, said deflector deflecting said copy sheet downwardly through a developing station.

18. The copying machine as set forth in claim 15 wherein said transport means comprise an upper transport roller in nip-forming relationship with a split lower transport roller, said lower transport roller having an axis coincident with the axis of said pivotable member, and wherein said sheet separating member is disposed in the split of said lower transport roller.

19. The copying machine as set forth in claim 18 including additionally: stripper means disposed on each side of said separator member for insuring positive removal of said copy sheet.

20. A method of separating superimposed sheet material having congruent leading edges comprising the steps of:

d. releasing said arrested sheet; and e. guiding said arrested sheet along a path different than said given sheet transport path.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent 3,5u2,361 Dated November 2a, 1970 Inventor(s) Daniel Call It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line 29, after "wherein" should read w said sheet arresting means comprising a tang protruding from said pivotable member in said transport path and lines 32 through 34, cancel "preceding said tang; and further including means normally biasing said pivotable member such that its guiding surface".

Signed and sealed this 7th day of November 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTISCHALK Attesting Officer Commissioner of Pater

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