EP2868486A2 - Vacuum drum, in particular for an inserter machine - Google Patents

Abstract

Described and illustrated is a suction drum (1), in particular for an inserter, with a lateral surface (2), wherein in the lateral surface (2) openings (3) are formed, wherein the lateral surface (2) rotationally symmetrical to a rotation axis (4) of Suction drum (1), and wherein the contour of the lateral surface (2) by a with the axis of rotation (4) lying in a plane surface line (5) is described. A suction drum (1), with which a reliable separation of paper from a stack of paper is possible is realized by the surface line (5) in the longitudinal direction of the axis of rotation (4) at least two different distances from the axis of rotation (4).

Description

The invention relates to a suction drum, in particular for an inserter, with a lateral surface, wherein in the lateral surface openings are formed, wherein the lateral surface is rotationally symmetrical to a rotational axis of the suction drum, and wherein the contour of the lateral surface by a lying with the axis of rotation in a plane surface line is described.

In different machines, eg. As folding machines, creasing machines, printers or inserters, is a separation of elements of a stack, for example sheets of a paper stack or envelopes required. For example, rollers or segment rollers with a friction lining are used for singling. Furthermore, suction elements such as suction drums are used. Especially at high cycle times, the error-free separation, especially of paper, is a challenge.

Suction drums often operate using a valve-controlled vacuum / blown air system, wherein the suction drum is cyclically subjected to a negative pressure, whereby an element to be separated, z. B. a sheet of paper, temporarily sucked and transported by the continuously rotating suction drum until the next transport. The suction drum has for this purpose a circular cylindrical lateral surface. The negative pressure acts via the openings in the lateral surface, so that when the negative pressure is applied, an intake of air through the openings in the jacket takes place and the element to be separated is sucked. The suction drum is advantageously arranged below a magazine, in which a stack to be separated is inserted. The frequency of the applied negative pressure determines the clock frequency of the promotion of the elements to be separated.

The known from the prior art suction drums have, inter alia, the disadvantage that a fault-free separation and error-free promotion, especially wavy paper, can not be reliably ensured.

The present invention is therefore based on the object of specifying a suction drum with which a reliable separation of paper from a stack of paper is possible.

The above object is achieved according to the present invention initially and essentially by the fact that the surface line in the longitudinal direction of the axis of rotation has at least two different distances from the axis of rotation. By "distance to the axis of rotation" is meant the distance from the center line of the axis of rotation of the suction drum to the lateral surface of the suction drum - outer surface at a certain point. For each point in the course of the generatrix, a certain distance to the axis of rotation can be determined. The distance is the length of an orthogonal line to the axis of rotation at a certain point. According to the present invention, this distance, in contrast to known circular cylindrical suction drums, not constant over the entire length, but the distance of the surface line to the axis of rotation varies and is different in particular at least two points in the course of the generatrix. By such a design of the suction drum, the support of a paper stack on the suction drum and the separation of the single sheet to be conveyed is improved in a surprising manner.

The relevant lateral surface of the suction drum is the lateral surface, which serves in the operation of the handling of paper objects are not relevant, for example, remote areas, which are provided for the storage or attachment of the suction drum. Preferably, the lateral surface in the edge regions - left and right - offset by a vertical paragraph of the attachment areas of the suction drum. The lateral surface is limited in both side areas by a vertical paragraph.

The drum is advantageously rotatably mounted in an inserter below a contact area or a magazine, so that the suction drum rotates in operation about its axis of rotation. The drum is preferably mounted so that its lateral surface projects slightly beyond the supporting areas of the inserting machine surrounding it. The suction drum is advantageously mounted on its two end faces in the machine. The suction drum is preferably hollow from the inside or has channels for guiding a negative pressure - Vacuum - on, at least in such a way that the cyclically existing negative pressure via the openings with the element to be separated interacts. The openings are preferably distributed uniformly in the lateral surface. However, it is also provided that the openings in the lateral surface are arranged in the form of a pattern, for example in the form of a plurality of unilaterally open triangles. The triangles are oriented, for example, in or against the direction of rotation.

The contour of the lateral surface, d. H. the outer shape of the lateral surface viewed in the direction of the axis of rotation is described by a lying with the axis of rotation in a plane surface line. The surface line can be seen for example in a section through the suction drum in each plane in which the axis of rotation is located. The contour of the suction drum is thus formed by a - imaginary - rotation of the generatrix around the axis of rotation. The lateral surface of the suction drum is consequently a rotary body. The generatrix extends between the preferably mutually parallel end faces of the suction drum.

According to a first embodiment of the suction drum, it is provided that the surface line has at least two different gradients in the longitudinal direction of the axis of rotation. The slope of the generatrix, viewed in the longitudinal direction of the axis of rotation, consequently changes at least once in the course of the generatrix, so that at least two different gradients are present. By such a design of the lateral surface of the suction drum, the reliability of the separation, especially at high clock frequencies, increased.

According to a further particularly preferred embodiment of the suction drum is provided that the surface line has at least partially a curve, preferably a symmetrical curve, particularly preferably a parabolic curve. The surface line is consequently formed, at least in sections, by a curved curve which extends between the two end faces of the lateral surface of the suction drum. It has proven to be advantageous if the curve is symmetrical to the center of the surface line, so that a mirrored curve is formed on both sides of the center. Intended are, for example, arc or sinusoidal curves, wherein preferably in the middle of the lateral surface - viewed in the longitudinal direction of the axis of rotation - a high point is arranged.

Particularly preferred is a parabolic-like curve of the generatrix, which is preferably arranged symmetrically to the total length of the generatrix. By such a curve results in a barrel-like or spherical suction drum, the high point is exactly in the middle of the generatrix. The contour of the suction drum or the lateral surface is convex. In such a contour of the lateral surface are the smallest distances between the axis of rotation - the center line of the axis of rotation - and the surface line in the end regions of the lateral surface at the end faces of the lateral surface. The largest distance is available at the high point of the generatrix, so that the lateral surface of the suction drum is bulbous.

According to a further embodiment of the suction drum, advantageous separation can also be achieved in that the surface line comprises, at least in sections, at least two straight lines with different slopes, in particular two straight lines with opposite slopes. The two straight lines preferably meet in the middle of the generatrix, wherein it is preferably provided that the two straight lines have opposite slopes, so that the generatrix also has a high point in the middle.

The reliability of the separation of a paper stack is increased according to a further embodiment in that the surface line has such a course that at least one circumferential recess is formed in the lateral surface. The circumferential recess is formed, for example, in a convex contour of the lateral surface - parabolic-type generatrix - by an opposite curve, so that a circumferential, trough-shaped recess is formed in the lateral surface; the circumferential return is semicircular. Such a return has the advantage that a sheet of paper or an envelope can advantageously rest on the outer surface of the suction drum, be detected by the applied vacuum and transported by the suction drum, without resulting in suction of two or more sheets.

The suction drum can be used advantageously in a machine, in particular an inserting machine, if it is provided according to a further embodiment that a connection means for a vacuum system is provided on at least one side surface of the suction drum. The connection means is optionally formed integrally with the suction drum or separately and arranged on or at least partially in the suction drum. It is advantageously provided that the connection means is at least partially inserted into the suction drum open on one side, and that with the connection means the application of a vacuum to the openings in the suction drum is realized. The connection means is preferably fixed, so that the suction drum rotates relative to the connection means. The suction drum is preferably at least partially rotatably mounted on the connection means.

It is preferably provided that the connection means is designed such that in each case seven openings can be acted upon simultaneously with a vacuum. Optionally, it is also provided that the openings have a deviating from the channels in the connection means arrangement, so that the channels are arranged in the connection means in the form of a straight line, while the openings are arranged arrow-shaped. As a result, the openings in the operating state are delayed in time with a vacuum acted upon.

According to a further embodiment of the suction drum is provided that the difference between the largest distance and the smallest distance between 5 mm and 15 mm, in particular between 7.5 mm and 12.5 mm, preferably 9.5 mm. The smallest distance is preferably realized in the end regions on the end faces of the lateral surface, wherein the largest distance is preferably present exactly in the middle. With such a course of the generating line can be particularly reliable to ensure that, for example, sheet is removed from a stack isolated.

Furthermore, according to a next embodiment, it is provided that the smallest distance between the axis of rotation and the surface line is between 15 mm and 100 mm, in particular 29.75 mm. By this distance, the smallest outer radius of the suction drum - the lateral surface - set, wherein Especially at this size special advantages in the separation of conventional paper formats, especially DIN A4, result.

Furthermore, according to a further embodiment, it is provided that the greatest distance is between 30 mm and 200 mm, in particular 34.5 mm. Such a maximum outer radius of the suction drum - the lateral surface - ensures a compact size and reliable conveying properties. The length of the lateral surface - projected onto the axis of rotation - according to another embodiment, preferably has a length between 60 mm and 90 mm, in particular a length between 70 mm and 80 mm.

Fig. 1

ein Ausführungsbeispiel einer Saugtrommel in Seitenansicht,

Fig. 2

ein Ausführungsbeispiel einer Saugtrommel in Seitenansicht,

Fig. 3

das Ausführungsbeispiel einer Saugtrommel gemäß Fig. 1 in perspektivischer Seitenansicht,

Fig. 4

ein Ausführungsbeispiel einer Saugtrommel in Seitenansicht,

Fig. 5

ein Ausführungsbeispiel einer Saugtrommel in Seitenansicht,

Fig. 6

ein Ausführungsbeispiel einer Saugtrommel in Seitenansicht, und

Fig. 7

ein Ausführungsbeispiel einer Saugtrommel in Seitenansicht.

In particular, there are now a variety of ways to design and develop the suction drum. Reference is made to both the patent claim 1 subsequent claims and to the following description of preferred embodiments in conjunction with the drawings. In the drawing show:

Fig. 1

an embodiment of a suction drum in side view,

Fig. 2

an embodiment of a suction drum in side view,

Fig. 3

the embodiment of a suction drum according to Fig. 1 in a perspective side view,

Fig. 4

an embodiment of a suction drum in side view,

Fig. 5

an embodiment of a suction drum in side view,

Fig. 6

an embodiment of a suction drum in side view, and

Fig. 7

an embodiment of a suction drum in side view.

Fig. 1 shows an embodiment of a suction drum 1 in side view. The illustrated suction drum 1 is particularly suitable for separation of stacked elements, eg. As deposits, paper or envelopes. For this purpose, the suction drum 1 is arranged, for example, in a rotating manner in the contact region of an inserting machine (not shown), wherein a lateral surface 2 of the Suction drum 1 comes into contact with the elements to be separated. For detecting the elements - the individual paper sheets - a plurality of openings 3 are formed in the lateral surface 2. These openings 3 are uniformly distributed in the lateral surface 2 and are arranged in this embodiment in the form of a plurality of downwardly directed, one-sided open triangles. The tip of the triangles points in the direction of rotation. The openings 3 are cyclically acted on by a - not shown - valve-controlled vacuum / blown air system with a vacuum, whereby the elements to be separated detected by the suction drum 1, pulled out from under the stack and transported to another conveyor. The lateral surface 2 is rotationally symmetrical to a rotational axis 4 of the suction drum 1 is formed.

In the side view according to Fig. 1 is clearly visible that the contour of the lateral surface 2 is described by a lying with the axis of rotation 4 in a plane surface line 5. By an imaginary rotation of the generatrix 5 about the axis of rotation 4, the rotationally symmetrical lateral surface 2 is described. In this exemplary embodiment, the generating line 5 has a parabolic curve which is arranged symmetrically with respect to the longitudinal direction of the lateral surface 2-the suction drum 1-such that the high point of the generating line 5 lies in the middle of the lateral surface 2. The suction drum 1 thereby has a crowned or barrel-like contour. The surface line 5 is limited in the side areas by a vertical paragraph.

Fig. 2 shows an embodiment of a suction drum 1, which also has a rotation axis 4 to the rotationally symmetrical lateral surface 2 with openings 3. The surface line 5 in turn has a convex, parabolic curve shape. The generatrix 5 is further designed so that the parabolic curve is interrupted in the central region, so that in the lateral surface 2, a circumferential recess 6 is formed. The recess 6 is formed by a counter to the other areas of the surface line 5 curve, so that a semicircular, circumferential recess 6 is present. This recess 6 has the advantage that in particular bent paper can be separated more reliably.

Im - according to Fig. 2 - Left side portion shown the suction drum 1 is provided on the side surface of a bearing pin 8 for supporting the suction drum 1. The right side of the suction drum 1 is open, so that a - in Fig. 7 shown - connecting means 7 for connecting a vacuum / blown air system can be inserted. The smallest distances between the axis of rotation 4 and the surface line 5 are realized in this embodiment in the end regions of the lateral surface 2 - left and right. The largest distances are in each case at the transition areas to the recess 6 - left and right of the recess 6 - formed.

Fig. 3 shows the embodiment of a suction drum 1 according to Fig. 1 in perspective side view. The convex outer contour of the lateral surface 2 can be clearly seen. Furthermore, it can be seen that the suction drum 1 is hollow from the inside, so that the 2- in Fig. 7 shown - connecting means 7 can be used as a distribution system for the suction and blowing air.

Fig. 4 shows an embodiment of a suction drum 1, the lateral surface 2 is also rotationally symmetrical to the axis of rotation 4 of the suction drum 1. The openings 3 are uniformly distributed in the lateral surface 2 and arranged in a plurality of unilaterally open triangles. In this embodiment, the surface line 5 - according to Fig. 4 Seen from left to right - initially a course with a straight line, wherein in the central region followed by a curved curve, which is subsequently provided again a straight line. The two straight lines have an opposite slope in this arrangement. By such a construction of the generating line 5, the lateral surface 2 of the suction drum 1 also receives a substantially bale-like or barrel-like outer contour. In this case, the side areas in which the surface line 5 is a straight line are clearly delimited from the middle area, namely by a circumferential edge at the transition areas.

Fig. 5 shows an embodiment of a suction drum 1, the lateral surface 2 is also rotationally symmetrical to the axis of rotation 4 of the suction drum 1. The lateral surface 2 has uniformly distributed openings 3 in the form of holes. The openings 3 are arranged in the form of a plurality of unilaterally open triangles to each other. The generatrix 5 has - according to Fig. 5 viewed from left to right - initially a convex curve - such as the embodiment according to Fig. 1 -, wherein in the central region a straight line follows and finally again a convex curve is arranged. Also, by such a construction of the generating line 5, the suction drum 1 receives a substantially spherical outer contour. The edge regions are clearly delimited from the central region, namely by two circumferential edges.

Fig. 6 also shows an embodiment of a suction drum 1 with a rotationally symmetrical to the rotation axis 4 formed lateral surface 2. The lateral surface 2 has evenly distributed openings 3, which are arranged in this embodiment in the form of a unilaterally open triangle. The generating line 5 is composed in this embodiment of two straight lines, wherein the straight lines in the longitudinal direction of the axis of rotation 4 have two opposite slopes. The slope is only very small, so that a substantially spherical outer contour of the lateral surface 2 is present. The suction drum 1 or the lateral surface 2 is formed symmetrically to the center of the lateral surface 2, so that the culmination of the course of the surface line 5 is located in the middle.

Fig. 7 shows an embodiment of a suction drum 1 with a rotationally symmetrical to the axis of rotation 4 formed lateral surface 2 in a sectional side view. The suction drum 1 is rotatably mounted on the left side with the bearing pin 8 in a bearing. In the hollow suction drum 1, at least partially, a connection means 7 is inserted from the right side, which serves for connection to a suction and blowing air system. In order to apply a vacuum to the openings 3 of the suction drum 1, channels 9 are provided in the connection means, which channels are arranged side by side in the form of a straight line in this exemplary embodiment. The connection means 7 is fixed, so that the suction drum 1 moves relative to the connection means 7. The suction drum 1 is rotatably mounted on the connecting means 7.

The openings 3 in the lateral surface 2 of the suction drum 1 are arranged arrow-shaped in this embodiment, so that the openings 3, which are arranged in the form of a straight line, are applied in operation delayed in time with a vacuum.

Claims (12)

Suction drum (1), in particular for an inserter, with a lateral surface (2), wherein in the lateral surface (2) openings (3) are formed, wherein the lateral surface (2) rotationally symmetrical to a rotation axis (4) of the suction drum (1) , and wherein the contour of the lateral surface (2) is described by a surface line (5) lying in a plane with the axis of rotation (4),
characterized,
that the circumferential line (5) in the longitudinal direction of the rotation axis (4) has at least two different distances from the axis of rotation (4). Suction drum (1) according to claim 1, characterized in that the surface line (5) in the longitudinal direction of the axis of rotation (4) has at least two different gradients. Suction drum (1) according to claim 1 or 2, characterized in that the surface line (5) at least in sections has a curve, preferably a symmetrical curve, particularly preferably a parabolic curve. Suction drum (1) according to one of claims 1 to 3, characterized in that the surface line (5) at least in sections comprises at least two straight lines with different slopes, in particular comprises two straight lines with opposite slopes. Suction drum (1) according to one of claims 1 to 4, characterized in that the surface line (5) has a profile such that at least one circumferential recess (6) in the lateral surface (2) is formed. Suction drum (1) according to one of claims 1 to 5, characterized in that on at least one side surface of the suction drum (1) is provided a connection means for a vacuum system. Suction drum (1) according to one of claims 1 to 6, characterized in that the difference between the largest distance and the smallest distance between 5 mm and 15 mm, in particular between 7.5 mm and 12.5 mm, preferably 9.5 mm. Suction drum (1) according to one of claims 1 to 7, characterized in that the smallest distance between 15 mm and 100 mm, in particular 29.75 mm. Suction drum (1) according to one of claims 1 to 8, characterized in that the largest distance is between 30 mm and 200 mm, in particular 34.5 mm. Suction drum (1) according to one of claims 1 to 9, characterized in that the length of the lateral surface is between 60 mm and 90 mm, in particular between 70 mm and 80 mm. Inserting machine for filling an envelope with a paper insert, comprising at least one suction drum (1) according to one of Claims 1 to 10. Use of a suction drum (1) according to one of claims 1 to 10 in an inserting machine for separating paper objects.

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