US3392856A

US3392856A - Method for separating at predetermined locations a plurality of flat articles at least partly lying one on the other

Info

Publication number: US3392856A
Application number: US586376A
Authority: US
Inventors: Reist Walter
Original assignee: Ferag AG
Current assignee: Ferag AG; Ferag Fehr and Reist AG
Priority date: 1965-10-21
Filing date: 1966-10-13
Publication date: 1968-07-16
Anticipated expiration: 1985-07-16
Also published as: NO118030B; NL153499B; FI45941C; CH440339A; BE688720A; SE328309B; NL6614840A; DE1511593A1; DK119041B; AT255974B; FI45941B; GB1150917A

Description

United States Patent METHOD FOR SEPARATIN G AT PREDETERMINED LOCATIONS A PLURALITY OF FLAT ARTICLES AT LEAST PARTLY LYING ONE ON THE OTHER Walter Reist, Hinwil, Switzerland, assignor to Ferag, Fehr & Reist AG, Zurich, Switzerland No Drawing. Filed Oct. 13, 1966, Ser. No. 586,376 Claims priority, application Austria, Oct. 21, 1965, A 9,565/ 65 8 Claims. (Cl. 214-152) A very large number of objects handled in industry and in trade have a flat shape, as, for example, paper, cardboard, pasteboard, textile fabric, felt, or synthetic plastic sheets; sheet metal or panels of wood, plywood, synthetic plastic, or corrugated board; as well as various articles comprised of individual sheets folded 0r sewn or otherwise bound together. The list is exemplary, and hardly exhaustive.

During their manufacture, processing, or treatment these articles are handled manually or by machine, and for this reason as a rule they are put in an orderly arrangement for storage or transport.

The most obvious arrangement is to have the flat objects lying at least partly one on the other. A pile, a series of sheets, a stack of sheets bound together along one edge in the manner of a publication: these along can be considered as being the orderly arrangement envisaged, wherein the individual fiat objects lie at least partly one on the other.

When handling such stacks, particularly when handling them mechanically, the problem often arises of separating the stacks at one or more predetermined places. Often it is neither desired nor even possible to remove the flat objects one at a time from a stack until the predetermined place has been reached, and to form a new stack with the removed objects. A procedure of this kind requires a relatively great amount of time and is accompanied by various disadvantages, according to the nature of the flat objects. For example, when removing individual metal panels from a stack for counting, the panels can damage each other, or in the case of thin paper sheets the latter can be crumpled. Moreover, because of the time required such a procedure is unthinkable when a large number of copies of a publication, such as a newspaper or periodical, must be opened at a desired place for inserting a supplement. To solve the problem of separating a stack at a predetermined place, it has been suggested that the place be found by counting, or measuring the thickness, down or up to the desired place, and inserting a separating element at the place thus found. However, the supplementary equipment required for this Procedure is quite expensive, relatively difficult to set up and operate, and is insutficiently reliable, particularly with flat objects that are not perfectly smooth or that are thin. This says nothing of the fact that in certain cases the separating element or the equipment for counting or measuring the thickness can damage the surfaces of the flat objects.

The object of the invention is a method for separating stacks of the aforesaid kind, which method very greatly reduces the disadvantages, and entirely avoids certain of the difiiculties, set forth above.

The invention is based upon the fact that there is always a certain static friction between neighboring flat objects of a series of such articles that are at least partly lying one on top of the other.

In accordance with the invention, means are provided, either before or at the time that the stack is formed for reducing the static friction between adjacent flat objects of the stack at the one or more places it is desired to separate the stack.

Several exemplary embodiments of the invention will now be described.

The object of the first embodiment is to reduce a stack of panels (sheet metal, plywood, cardboard, or synthetic plastic, for example) of equal size, by removing, for instance, four panels each time from the stack. When the panels are originally stacked, one surface of every fourth panel is provided with a low-friction coating in the form of a fluid or dry lubricant which is harmless to the material of the panel. Or the surface is made smooth, provided that this is compatible with the later use of the panel. Or a very low-friction sheet, such as oil paper or a sheet of synthetic plastic, can be inserted between every fourth panel when the stack is formed.

The positions of the coating, the polished surface, or of the low-friction sheet are not visible in the stack. These positions will henceforth be termed low-friction positions.

If a force, parallel to the stack surface, is applied to the top panel, the four uppermost panels will move, rather than only the top panel, because the static friction between adjacent panels of this group of four panels is far greater than that between the fourth and fifth panels. Moreover, the stack will not separate at the next lower low-friction position, because the static friction, in consequence of the four additional panels, is greater here than at the first low-friction position. As soon as the first four panels have thus been shifted, the exposed surface can be engaged by conventional transport equipment and the group of four panels removed. The next four panels are now ready for removal.

The object of the second embodiment is to open at a predetermined page or place each of a plurality of copies of printed matter, such as periodicals. Each copy is formed of a stack of sheets by folding or by stapling, sewing, or gluing along one edge. At least one of the two surfaces, between which the desired place is located, is sprayed with a low-friction material, such as a dry lubricant. In the case of newspapers, talcum powder is a suitable lubricant. When a copy is to be opened at the desired place, a force is applied to one side of a copy in a direction approximately parallel to the sheets of the copy and having at least a component that is not perpendicular to the folded or bound edge in the general plane of the sheets. The sheets of the copy located between the side to which the force is applied and the said desired place are consequently drawn back and raised, whereby a surface is exposed to enable operation of the mechanism which is necessary for further opening the copy. The force can be applied, for instance, by causing the group of sheets located on one side of the desired place to move against an abutment which engages an unbound or unfolded edge of the outermost sheets of the group, while continuing to advance the copy a predetermined distance. The group of sheets will behave as a unit. Not only the sheets actually held by the abutment but all of the sheets of the group, because of the friction between neighboring sheets, will be prevented from advancing farther, whereas the group of sheets on the other side of the desired place, because the two groups of sheets are separated by a lubricant, are free to continue moving. In thi manner, the copy is opened at the desired place.

The object of the third embodiment is to remove a desired number of sheets each time sheets at a time, for example) from a stack of normal-sized sheets of writing paper that have been blanked from a stack of the larger sheets as produced by the paper manufacturer. In carrying out this embodiment of the method, a very low friction sheet, such as a supercalendered paper of the greatest smoothness, is inserted between every hundred of the larger sheets as they are stacked. Sixteen normalsized sheets may be cut from a single one of the larger sheets, for example. After the stack of larger sheets is blanked in a single operation, and the blanked sheets stacked, the resultingstack of sheets is sixteen time as high as the original stack. Since the low-friction sheets were also blanked, there is such a sheet located every one hundred sheets in the stack. To remove the sheets one hundred at a time, a lateral force is applied to one of the upper edges of the stack, causing a smooth movement of the top one-hundred sheets, While the rest of the stack remains stationary and undisturbed.

The means chosen to reduce the friction depends on the kind of fiat articles stacked and on their properties. It lies within the purview of the invention for the professional to choose the necessary and desirable means, as well as the manner of applying the force. In this connection, if the force is applied at an acute angle, rather than approximately parallel, to the sheet surface, the component normal to "the sheet surface has the effect of temporarily changing the force of static friction between the sheet surfaces. In certain instances this can be advantageous.

In accordance with the invention, it is sometimes necessary to lubricate or render smooth only a part of the surface of a fiat object or to insert a low-friction sheet that covers only a part of the surfaces of the adjacent fiat objects, in dependence on such factors as the size of the fiat objects, their weight, relative smoothness or roughness of their surfaces, and the number of flat objects to be moved at a time.

The invention admitting of various modifications, its scope is determined solely by the appended claims.

I claim:

1. Method for separating at a predetermined location a plurality of fiat objects lying at least partly one on the other to form a stack; reducing the static friction between opposed surfaces of two adjacent flat objects at -the loeation at which it is desired to separate the stack;

and applying to the flat objects located on one side of said location a force having at least a component in the plane of the fiat objects, such as to separate the stack at said location. 7

2. The method as defined in claim 1, wherein the first step includes reducing the static friction between at least a part of the area common to the said two opposed surfaces.

3. The method as defined in claim 2, wherein the first step consists in reducing the static friction before a one of said two adjacent fiat objects is laid on the other.

4. The method as defined in claim 3, wherein said first step consists in reducing the static friction over at least a portion of at least one of said two opposed surfaces.

5. The method as defined in claim 4, wherein said first step consistsin coating at least a portion of at least one of said two opposed surfaces with a lubricant.

6. The method as defined in claim 4, wherein said first step consists of rendering at least a portion of at least one of said two opposed surfaces smoother than the surfaces of the other fiat objects.

7. The method as defined in claim 3, wherein said first step consists of laying a low-friction sheet on one of said two opposed surfaces.

8. The method as defined in claim 5, wherein said lubricant is dry.

References Cited UNITED STATES PATENTS BERNARD STICKNEY, Primary Examiner.

Claims

1. METHOD FOR SEPARATING AT A PREDETERMINED LOCATION A PLURALITY OF FLAT OBJECTS LYING AT LEAST PARTLY ONE ON THE OTHER TO FORM A STACK; REDUCING THE STATIC FRICTION BETWEEN OPPOSED SURFACES OF TWO ADJACENT FLAT OBJECTS AT THE LOCATION AT WHICH IT IS DESIRED TO SEPARATE THE STACK; AND APPLYING TO THE FLAT OBJECTS LOCATED ON ONE SIDE OF SAID LOCATION A FORCE HAVING AT LEAST A COMPONENT IN THE PLANE OF THE FLAT OBJECTS, SUCH AS TO SEPARATE THE STACK AT SAID LOCATION.