US3278180A - Sheet separating - Google Patents

Description

Oct. 11, 1966 D w. SLEEPER ETAL 3,278,180

SHEET SEPARATING Filed April 15, 1964 5 Sheets-Sheet 1 FIG. I

INVENTORS.

NORMAN W. TAYLOR 8| DONALD W- SLEEPER ATTORNEY Oct. 11, 1966 D. w. SLEEPER ETAL SHEET SEPARATING Filed April 15, 1964 5 Sheets-Sheet 2 INVENTORS.

TAYLO R 8| NORMAN W. F DONALD W. SLEEPER ATTORNEY 1966 o. w. SLEEPER ETAL 3,278,180

SHEET SEPARATING Filed April 15, 1964 III-I... a

5 Sheets-Sheet 5 FIG. 6

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I r: INVENTORS.

NORMAN W. TAYLOR a 464 BYDONALD W. SLEEPER MK/QOZ- ATTORNEY United States Patent 3,278,180 SHEET SEPARATING Donald W. Sleeper, Euclid, and Norman W. Taylor, Cleveland, Ohio, assignors to Addressograph Multigraph Corporation, Cleveland, Ohio, a corporation of Delaware Filed Apr. 15, 1964, Ser. No. 360,011 Claims. (Cl. 271-19) This invention relates to sheet handling and especially to the separation of sheets, one-by-one, from the top of a stack of sheets and forwarding them for being worked upon, for example by a printing machine.

Heretofore in medium cost sheet handling equipment devices, sometimes referred to as corner separators, have been employed which provide front stops for the corners of a stack of sheets and from whic the top sheet can escape when moved forward by a sheet moving element. While these prior devices can sometimes be made to operate fairly effectively with the paper of certain types, they have little flexibility and will normally handle only very usual types and sizes of paper. When wide variations from the normal are encountered, the corner separators usually must be changed, or in some cases cannot be made to work at all.

It is an object of the invention, therefore, to provide a corner separator arrangement in which the corner separator elements have a novel configuration calculated to provide wide latitude in the types of paper that can be handled without changing separators, and which will reliably separate sheets one-by-one from the stack over a wide range of paper weights, paper surfaces, and sheet sizes.

It is another object of the invention to provide an improved corner separator arrangement capable of cooperating with an adjustable pressure setting such that the corner separators can be made to positively depress the corners of the sheets to a certain predetermined degree, which degree is capable of adjustment in order to further extend the range of conditions under which sheets may be reliably separated and fed forward.

It is a further object of the invention to provide corner separators which combine positive retention features for the lower sheets while generating a positive release action for the top sheet.

The provision of corner separators capable of the foregoing flexibility and wide range of effectiveness, but not adding significantly to the cost of equipment, is also an object of the invention.

Other objects, features and advantages will appear hereinafter as the description proceeds.

In the drawing:

FIG. 1 is a fragmentary longitudinal section of a printing machine employing the corner separators of the present invention;

FIG. 2 is a front elevation of a corner separator element looking from the direction of the paper pile;

FIG. 3 is a right side elevation of the device of FIG. 2 to a larger scale;

FIG. 4 is a fragmentary top plan of the corner sepa rator of FIG. 2;

FIG. 5 is a partial back elevation of the upper portion of the corner separator element of FIG. 3, showing the relationship of the sheets thereto during operation and prior to a starting motion;

FIGS. 6 to 9 are schematic sectional views to a large scale, looking from the same direction as FIG. 2, and illustrating the position of the sheet in various stages of the separating action.

Referring to the drawing, FIG. 1 shows one form of printing machine in which the corner separators of the present invention find application. The machine comprises parallel side plates, one of which is indicated at 3,278,180 Patented Oct. 11, 1966 11, between which are mounted printing elements, for example the printing'cylinder 30 and the platen cylinder 40. Means including feed rollers 101 and 102 are provided for presenting a sheet of paper to the bight of cylinders'30 and 40 at the proper moment to be printed, and a sheet separating and starting device 300 is provided for separating the top sheet from a stack of sheets S on a paper table 401, and moving the same forward into the control of the feed rollers 101, 102. The table carries members 403 and 405 vertically slidable in guide slots 407 and 409 on the machine frame. Means (not shown) is preferably provided for automatically bringing the table to a height such that the top sheet of the stack S will be presented at a predetermined level. Various ways of arranging this are known, for example that illustrated in the US. Patent to Curtis, No. 2,165,232, so that no additional description or showing is necessary.

The sheet starting device 300 comprises an oscillating lever 303, the lower tip of which appears in the drawing, and which is driven in time with the rotation of printing cylinder 30. To the lever 303 is pivotally connected a rack 365, which meshes with a pinion which drives a shaft 353 via an over-running clutch 361 so that shaft 353 turn in one direction only.

Drivingly associated with the shaft 353 are one or more rollers such as that indicated at 351 which have friction contact with the top sheet of the stack S and which are rotated in the direction of the arrow to move the top sheet to the right. Means such as adjustable tension springs 369 may be employed to provide the proper degree of friction between the roller and the sheet.

The action of separating the top sheet from the pile and doing so reliably for various kinds and weights of paper is achieved according to the present invention in a novel and inexpensive Way involving the cooperation of the roller on rollers 351 with means at each of the two corners of the paper pile nearest the feed rollers 101, 102. These means are referred to as corner separators and act partly as front stop means for the pile, and also as means to release the sheet from such front stopped condition in response to forward urging of the sheet. One of these corner separators is shown in FIGS. 2 to 9 of the drawing where it is indicated generally by the reference character 450. While in each view only that member 450 which is on the left hand side of the machine is illustrated, it will be readily understood that there will usually also be such a member on the right hand side of the machine, which member is identical except for being of opposite hand. Each of the corner separators 450 is made of two sheet metal plates. The main plate 451 has a flange 453 turned at right angles thereto along its outer edge, and at the upper end at the corner formed by said flange is a carefully formed cap configuration 455. This is characterized bv five important features:

(1) The forwardmost portion of the cap joins the plate 451 in a sloping crease 456, and is slightly flattened adjacent the crease 456 as indicated at 457 in FIG. 3 to form a narrow sloping ledge. The crease 456 is not sharp but rather has a noticeable interior radius.

(2) The ledge 457 and the crease 456 slope downwardly towards the flange 453 so that all three surfaces meet at a corner 459 which is at a lower elevation than the inner end of the crease 456. There is also a slight crease 460 in the flange running rearwardly from this corner on a slight upward slope.

(3) The innermost edge surface of the cap, indicated at 461, follows a generally helical path starting at the rearmost point 463 and winding forwardly, first upwardly and then downwardly, in a generally inward direction to merge with the rest of plate 451 at the inner end of crease 456.

(4) The surfaces of the cap portion, and especially the edge 461 have had their corners rounded and are very smooth, and have been treated to resist wear, as by chrome plating.

(5) The length-to-Width proportions of the cap element in plan view are also significant, and should be held very close to 8:3. For average paper feeding the length dimension L in FIG. 4 should be substantially /2 inch, and the width dimension W about inch.

The front wall of the separator just below the cap 455 slopes downwardly away from the flange 453 as indicated at 464 making an angle of a few degrees from the vertical, and the edges of this slope are also smoothed.

The rest of the corner separator is made up of an auxiliary plate 465 attached to plate 451 as by spot welding. The central horizontal section is bent to form a guide loop 467. At the outside end, portions of the plate 465 are extended beyond the flange 453 and bent to provide fingers 469 which form between themselves and the flange 453 a guide groove 471 for a purpose which will presently be explained.

The corner separators are mounted upon a rectangular bar 473 which runs across the machine at the inner end of the feed table 401, the bar 473 passing slidably through the loops 467, whereby the corner separators can be laterally positioned to suit the width of the sheets being fed. This positioning is automatically effected by adjustable side guides 475 which can be moved laterally and set in various positions on the feed table in any well known manner. The forward edge of each side guide 475 is designed to extend into the guide groove 471 of its corner separator 450 so as to move the same with it whenever a sheet width adjustment is made.

The corner separators 450 are also capable of simultaneous vertical adjustment. The bar 473 (FIG. 1) has extensions which are slidably mounted in slots 477 in the frame, one of which is shown in this view. At each end of the bar 473 there is a vertical operating member 479 secured to the bar and formed at its lower end with a follower cage 481 which embraces a cam 483. The two cams 483, one of which is shown in FIG. 1, are drivingly secured to a long shaft 485 which is rotatable in the side plates and carries at one end a suitable operating knob (not shown) by which both ends of the bar 473 can be simultaneously raised or lowered. A suitable friction detent such as a spring washer may be provided to maintain the shaft 485 in any desired adjusted position.

The operation of this vertical adjustment contributes an additional degree of flexibility. It is known that the most effective way to control accurate separation by corner separators is by placing light pressure on the corners of the sheets and causing the sheet to extract itself from this light frictioued retention. Such pressure is frequently provided by springs or weights applied to the separators but it has now been determined that it is much more effective to fix the corner separators at a predetermined level and then rely upon the automatic raising of table 401 to apply the proper degree of pressure to the corners by raising the top of the pile to standard height. The reason for this appears to be that the degree of pressure, to provide optimum functioning, should be adjusted to take care of different weights of paper and different surface characteristics. This arrangement renders the corner pressure delicately and infinitely adjustable in a simple manner without interchanging parts, and in such manner that the operator can readily change it during running to select the optimum pressure setting for existing conditions.

It will be understood that when a pile is in place on the table 401, and the table raising mechanism has brought the table to standard height, the setting of the corner separators will cause a slight downward compression on the pile corners, the degree of which depends upon the level at which bar 473 has been set. This condition is illustrated in FIG. 5 which represents what would be seen by an observer at the position of the feed roll 101 looking toward the left in FIG. 1. The corners of the upper sheet, therefore, are lightly trapped and downwardly deflected by the frictional action of the ledge portion 457 before the sheet starting action begins.

When the rollers 351 begin to turn, the sheet assumes a slight fore-and-aft upward buckle, extending across the front margin of the sheet, since the front edge is stopped against the plates 451 of corner separators 450. Very shortly, however, the buckling lateral edges of the sheet, by riding up the helical edges 461 of the caps 455 are cammed laterally towards each other and hence exert a stress which snaps the sheet corners inwardly towards each other until they are finally free of the light frictional pressure applied by ledges 457. Once the sheet corners are free, the sheet, still tending to straighten laterally, forces its edges first against the upper parts of edges 464, and then against the forward part of the curved edges 461. Since these slope outwardly and upwardly away from the center line in this zone, the sheet cams itself upward and then ultimately feeds forward riding the tops of the caps 455 to proceed towards the feed rollers 101, 102, providing an outstandingly reliable single sheet release action not heretofore achievable with separating equipment of this general nature and cost range.

The release action of the corner separators 450 can be adjusted as previously indicated, by lowering or raising the same with respect to the standard pile height as determined by the setting of the automatic raising mechanism for the table 401. This adjustment not only controls the amount of depression of the sheet corners, but also determines the precise width of front stop encountered due to the slope of edges 464. The specific shape of caps 455 heretofore described in cooperation with the slope 464 has provided an arrangement which reacts well for separating papers of many types, and the provision of corner pressure adjustment has extended this range even farther. With the arrangement shown and described it is found possible to feed reliably sheets varying in surface character from bond to parchment to calendered surfaces and possibly even certain coated stocks. Sheet sizes from 3" x 5" to 11" X 17" have been accurately and reliably separated. Even envelopes are properly fed. One of the main features is the provision of reliable retention for the sheets below the one being separated, which the pressure of sloping ledge 457 against the depressed corners nicely provides still without impairing release of the top sheet. The sequential action of releasing a sheet is shown in detail in FIGS. 6 to 9, taken in order. These are views looking towards the feed rollers 101, 102 and wherein the sheets of the sheet stack S are sectioned by a plane passing through the points of contact with the separators. This sequence of positions actually occurs very rapidly so that the corners of the sheet appear to snap out from under the corner separators. However, in spite of this the action is extremely smooth and controlled due to the particular shape of the separators themselves.

While in the foregoing description the use of two corner separators has been described and is normally preferable for the best control, it will be understood that a single corner separator will prove operable in many cases and the invention is not limited in this regard.

From the foregoing, it can be seen that we have provided an improved configuration for a corner separator which makes it possible for the operator of a machine such as a printing machine to successfully feed sheets of many times without making structural changes in the corner separator structure, and so that simple machine adjustments which can be effected while the machine is running are all that are required in order to provide a very wide latitude in the type and size of sheet being handled.

While the preferred embodiments of the invention have been described and illustrated, it is to be understood that these are capable of variation and modification. Accordingly, the aim of the appended claims is to cover all such variations and modifications as may fall within the true spirit of the invention.

What is claimed is:

1. A corner separator comprising a plate adapted to lie against the lead end of a stack of sheets adjacent to a corner thereof; and a cap at the upper end of said plate having an inner edge which proceeds from the side edge of the top sheet of the stack along a helix upwardly, inwardly and downwardly to a point near the leading edge of the sheet.

2. A corner separator comprising a plate adapted to lie against the lead end of a stack of sheets adjacent a corner thereof; and a cap having an inner edge which proceeds from the side edge of the top sheet along a helix upwardly, inwardly and downwardly to a point near the leading edge of the sheet, and a narrow ledge, forwardly and outwardly sloping, in intimate contact with a narrow margin of the sheet adjacent its leading edge.

3. A corner separator comprising:

a front wall adapted to lie against the lead end of a stack of sheets adjacent a corner thereof, said wall having an exterior edge positioned to parallel the corner of a stack of sheets;

a cap;

a front wall junction with said cap extending upwardly at an obtuse angle along said front wall junction and extending to said exterior edge, said cap sloping upwardly in all areas from said junction;

said cap having a cam edge beginning at said front wall junction a distance from said exterior edge and sloping away from said front wall at an acute angle in relationship to the lateral direction of said front wall, and at a slightly ascending angle with respect to the vertical plane of the front wall, and thereafter progressing upwardly and continuing in said acute angle relationship with respect to said front wall to an apex and then downwardly to a terminus about on a plane normal to said front at said wall exterior edge.

4. A corner separator comprising:

a front wall adapted to lie against the lead end of a stack of sheets adjacent a corner thereof;

a side Wall, said side wall and front wall meeting along a vertically extending fold;

a cap;

a front Wall junction with said cap extending upwardly along said front wall at an obtuse angle with respect to said fold;

a side wall junction with said cap extending upwardly along said side wall at an obtuse angle with respect to said fold;

said front and side wall junctions meeting at said vertically extending fold to form a converging threesurface corner of said front and side w-allls with said cap, said cap sloping upwardly in all areas from said three-surface corner;

said cap having a cam edge beginning at said front wall junction at distance from said corner and sloping upwardly from said front wall at a slightly ascending attitude, and thereafter progressing upwardly at a greater angle and toward said side wall to an apex and then downwardly to a terminus at the plane of said side wall;

whereby, the cap is embodied in two major portions, the one portion adjacent the front wall causing the corner of a top sheet in a stack to turn down, but prohibiting a full buckle at the corner, thereby conditioning the sheet to buckle laterally, and the other portion being an inwardly curving cam to press the sheet laterally and create a front end buckle.

5. Corner separator apparatus comprising:

guide means for establishing a work position for the sheets of a vertical stack of paper sheets in superposed relationship;

means for advancing the top sheet of a positioned stack in a direction along the plane of said top sheet;

an abutment surface adjacent the front position of a corner of a stack in said guide means for restraining sheets in the top area of a stack against free advance movement;

a cap ledge extending from said abutment surface over said work position in a canted attitude sloping upwardly in a direction toward the opposite corner position for restraining the top sheet against a free curve buckle in the direction of sheet advance and permitting a buckle laterally;

a turnboard cam rearwardly of said abutment surface continuing from said cap ledge over said work position, said cam and cap ledge having a common edge surface extending in a generally angularly direction across the corner of said work position.

References Cited by the Examiner UNITED STATES PATENTS 3,110,489 11/1963 Zahradnik 271-22 3,210,071 10/1965 Rogers 27122X M. HENSON WOOD, JR., Primary Examiner. I. N. ERLICH, Assistant Examiner.

Claims (1)

1. A CORNER SEPARATOR COMPRISING A PLATE ADAPTED TO LIE AGAINST THE LEAD END OF A STACK OF SHEETS ADJACENT TO A CORNER THEREOF; AND A CAP AT THE UPPER END OF SAID PLATE HAVING AN INNER EDGE WHICH PROCEEDS FROM THE SIDE EDGE OF THE TOP SHEET OF THE STACK ALONG A HELIX UPWARDLY, INWARDLY AND DOWNWARDLY TO A POINT NEAR THE LEADING EDGE OF THE SHEET.

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