JPH0859032A - Sheet paper inversion method and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To freely select laws of motion securing the minimum acceleration for the oscillation of a sheet receiving device by guiding printed sheets on a track deviated from the surface of a storage drum behind a common point of tangency of the storage drum and a reversing drum. SOLUTION: In the both-side printing operation, a printed sheet 8 is guided on a track deviated from the surface of an impression drum 4 after a paper gripper 7 is released, and the rear end of the sheet 8 is picked at a point of tangency t1:4 by a sheet receiving device 2 of a reversing drum 1 formed as a suction device. After that, the suction device 2 and the gripper oscillate and come closer to each other as publicly known, and the printed sheet 8 is brought from the suction device 2 to the gripper 3. After the gripper 3 oscillates and is separated, the printed sheet 8 moves forward with the rear end in front, reversed and transported continuously. Therefore, laws of motion and the separation angle can be selected according to conditions regardless of the relations between each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reversing a sheet in a sheet (single sheet) rotary printing machine capable of switching from single-sided printing to double-sided printing, and an apparatus for carrying out this method.

[0002]

2. Description of the Related Art A sheet reversing device for a sheet revolving printing machine which can be switched from single-sided printing to double-sided printing and operates on the trailing edge reversal principle is already known (see, for example, German Patent No. 4012498).

In the single-sided printing operation, the printed sheet is passed from the storage drum gripper to the reversing drum gripper at its leading edge at a so-called tangent point (contact point) between the storage drum and the reversing drum which acts as a transfer drum in this case. Be done.

In the double-sided printing operation, the printed sheet paper is guided over the tangent point by the storage drum gripper,
The trailing edge is gripped by the sheet receiving device of the reversing drum, which is designed as a suction device, after which it is transferred to the reversing drum gripper and then from this reversing drum gripper to the gripper of the next cylinder.

In order to reduce the separation angle α between the suction surface of the suction device of the reversing drum and the actual sheet feed direction, the suction device is corrected by the transmission device in the moving coordinate system of the rotating drum (storage drum / reversing drum). You will be guided on an involute orbit.

In this case, the movement path and the gearing used are complex, the gearing is very expensive (the control of the aspirator is carried out by two cam gears) and the control of the aspirator is However, there is a drawback in that the motion can be realized only with a large acceleration force because the optimum law of motion, such as Sinoide, cannot be used.

There is also known a sheet paper guide device formed as a guide blade in a sheet paper rotary printing machine which can be switched from single-sided printing to double-sided printing and operates on the trailing edge reversal principle (German Patent No. 4140762). See the book).

In this case, the sheet guide device, which is embodied as a guide blade, is arranged behind the opening point of the double-sided printing (gripper) with respect to the tangent to the impression cylinder with respect to the smallest size sheet (format), ie , Is arranged in the range from the smallest size sheet to the maximum position that can be executed (the largest size sheet). Therefore, when the double-sided printing open point is the same for all (size) sheets, the double-sided printing open point is different from the single-sided printing open point, so the maximum size sheet to be processed is It may be greater than the arc path on the impression cylinder from the point of contact between the impression cylinder and the reversing drum located after it to the point of contact between the impression cylinder and the preceding sheet guide cylinder.

In this device, the sheet paper path does not come to eliminate the above-mentioned drawbacks of DE 4012498.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to freely select a motion law that guarantees a minimum acceleration with respect to a swinging motion of a sheet paper receiving device, and regardless of this, a sheet paper of the sheet paper receiving device. It is an object of the present invention to provide a sheet paper reversing method in which the peeling angle between the contact installation surface and the sheet paper feeding direction can be freely selected and an apparatus for carrying out the method.

[0011]

One side based on the trailing edge reversal principle, in which a printed sheet guided on a storage drum is continuously conveyed while being gripped at its trailing edge by an oscillating sheet receiving device of the reversing drum. In a method of reversing a sheet of paper in a sheet-fed rotary printing press capable of switching from printing to double-sided printing, a printed sheet of paper is placed on a track deviated from the surface of the storage drum behind a common tangent point between the storage drum and the reversal drum. It is characterized by being guided.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail with reference to the embodiments shown in the drawings.

FIG. 1 shows a double-sided sheet-fed rotary printing machine having a reversing drum 1, a storage drum preceding it as a impression cylinder 4 and a sheet paper guide cylinder 5 preceded by the impression cylinder 4. The cylinder arrangement structure is shown. The term "storage drum" means here all cylinders and drums that guide the printed sheet paper beyond the point of contact (tangential point) between the storage drum and the reversing drum that follows it. This is, for example, an impression cylinder (see FIG. 1) or a drum arranged between the impression cylinders, depending on various configurations.

In the figure, t _{1; 4} is the reversing drum 1 and the impression cylinder 4.
Is a common tangent point with t _{4; 5} is a tangent point between the impression cylinder 4 and the sheet guide cylinder 5. A sheet paper gripper 7 is arranged on the impression cylinder 4, and a suction device 2 and a gripper 3 are arranged on the reversing drum 1. Instead of the suction device, other devices such as grippers, reversal grippers, etc. can be used as well. All these devices are included in the term "sheet receiving device".

Printed sheet paper 8 in single-sided printing operation
The front edge of is transferred from the gripper 7 of the impression cylinder 4 to the gripper 3 of the reversing drum. Single-sided printing opening point of the gripper 7 is tangent point t _1; if it matches with _4, the tangent point t ₁ in the sheet feed conveying _direction; located immediately after the _4.

Printed sheet paper 8 in double-sided printing operation
Is guided according to the invention on a trajectory deviating from the surface of the impression cylinder 4 after opening the paper gripper 7, and at the tangent point t _{1; 4 the} trailing edge of the trailing edge of the printed sheet 8 formed as a suction device. It is caught by the sheet receiving device 2 (position A in FIG. 1). After that, the suction device 2 and the gripper 3 are shaken and approached in a known manner, and the printed sheet 8 is transferred from the suction device 2 to the gripper 3 (position B in FIG. 1). After the gripper 3 is swung apart, the printed sheet of paper advances with its trailing edge forward,
That is, it is reversed and continuously conveyed (position C in FIG. 1).

Unlike the prior art in which the law of motion for the oscillating motion of the sheet paper receiving device 2 is determined only by considering the peeling angle (the angle between the sheet paper position and the contact installation surface of the sheet paper receiving device). In the case of the present invention, the law of motion and the peeling angle can be selected according to the conditions independently of each other. Preferably, a sinoidal motion law is selected for the oscillating motion, for example a Sinoide that guarantees a minimum acceleration for the motion of the sheet receiving device.

The peeling angle can be chosen independently of it, the peeling angle being in the range ± α where α is 0 to 10 °, preferably zero. The cost of the transmission is considerably reduced, since simple known transmissions are now available for realizing the oscillating movement according to the sinoidal law of motion. At the same time, by freely selecting the peeling angle, for example by selecting the peeling angle to be zero, the receipt of the sheet is qualitatively guaranteed.

The trajectory 13 through which the printed sheet 8 is guided according to the invention is determined on the basis of the selected law of motion and / or on the selected peeling angle or peeling angle range. Preferably, the orbit 13 has a sinoidal motion law selected, the swing motion range of the sheet paper receiving device 2 is a rotation angle of the reversing drum of 50 to 70 °, and the printed sheet paper 8 and the sheet paper receiving device 2 are Vector (Leitstrahlen) when the separation angle between -5 ° and + 5 °
Two envelopes bounded by 15 ° -5 °; 15
It is located in the range between + 5 °. The envelope 15 is shown in FIG.
The range formed by ° -5 °; 15 ° + 5 ° is shown.

The device for carrying out the method according to the invention (FIG. 2) has a guide blade 9. This guide blade 9 is arranged immediately after the common tangent point t _{1; 4} of the storage drum 4 and the reversing drum 1 placed behind it in the sheet conveying direction, and guides the printed sheet after the gripper 7 is opened. To do. The guide blade 9 associated with the storage drum 4 has a guide surface 10 corresponding to a track 13 on which the printed sheet is guided. The track 13, and thus the guide surface 10, is located within the envelope range 15 ° -5 °; 15 ° + 5 °, preferably the starting tangent range 10.1, the ending tangent range 1
0.3 and arcuate ranges connecting these ranges 10.
Have two.

Air guide means 12 are arranged on the guide blade 9. The air guide means 12 draws the printed sheet of paper to the guide surface 10 and supports relative movement of the printed sheet of paper in the sheet paper transport direction with respect to the guide surface 10, that is, guides the printed sheet of paper. An ejector (not shown) known per se is arranged on the gripper 7 for transferring the printed sheet 8 from the impression cylinder 4 to the guide blade 9.

The starting tangent range 10.1 of the guide surface 10 of the guide blade 9 is tangential to the tangent point t _{1; 4} or to another tangent point located in the range of this tangent point t _{1; 4.} Alternatively, they are arranged almost tangentially. The end tangent range 10.3 of the guide surface 10 is preferably the sheet receiving device 2
Is arranged tangentially or substantially tangentially to the sheet guide surface at the end point of the swing movement approaching movement.

In the case of different forms of sheet receiving device 2, for example a reversal gripper, the end tangent range 10.3 of the guide surface 10 is preferably tangential to, or approximately tangential to, the end of the swung-away position. It is arranged tangentially. The connection between the starting tangent area and the ending tangent area is preferably made by an arcuate area 10.2. The starting tangent range and / or the ending tangent range may be part of the arcuate range 10.2.

[0024]

According to the present invention, the law of motion for ensuring the minimum acceleration with respect to the oscillating movement of the sheet receiving device can be freely selected, and regardless of the law of movement, the sheet contact setting surface of the sheet receiving device can be selected. The peeling angle from the sheet paper feed direction can be freely selected.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a cylinder arrangement structure of a double-sided sheet paper rotary printing machine.

FIG. 2 is an enlarged detailed view of a range of tangent points t _{1; 4} .

FIG. 3 is an enlarged detailed view of a sheet paper guide trajectory range.

[Explanation of symbols]

1 Reversing Drum 2 Suction Device / Sheet Paper Receiving Device 3 Gripper 4 Impression Cylinder / Storage Drum 5 Sheet Paper Guide Cylinder 7 Sheet Paper Gripper 8 Printed Sheet Paper 9 Guide Blade 10 Guide Surface 10.1 Starting Tangent Line Range 10.2 Circular Arc Range 10.3 End tangent range 12 Air guiding means 13 Orbit 14 Vector 15 Envelope t _{1; 4} Tangent point (contact point) between impression cylinder and reversing drum t _{4; 5} Tangent point between impression cylinder and sheet paper guide cylinder (Contact point)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Victor, Heftler Germany Federal Republic of Coswig, Zerkowitzer, Strasse, 1B (72) Inventor Michael, Koch Kosebaud, Weinberg Strasse, 76 Tse (72) Inventor Gunther, Peter Radebeul, Germany, Crayer Wake, 11

Claims (16)

[Claims] 1. A single-sided printing to a double-sided printing based on a trailing edge reversing principle in which a printed sheet guided on a storage drum is continuously conveyed while being grasped at its trailing edge by an oscillating sheet receiving device of a reversing drum. In a method of reversing a sheet of paper in a sheet-fed rotary printing press, the printed sheet of paper (8) is behind a common tangent point (t _{1; 4} ) of the storage drum (4) and the reversal drum (1). A sheet paper reversing method, characterized in that it is guided on a track (13) which is deflected from the surface of the storage drum (4). 2. A printed sheet paper (8) guides on a trajectory (13) determined by a motion law which realizes a minimum acceleration with respect to the oscillating movement of a sheet paper receiving device (2) and can be freely selected. The sheet paper reversing method according to claim 1, wherein: 3. The sheet paper reversing method according to claim 2, wherein the motion law is sinoidal. 4. A track (13) in which the printed sheet (8) is determined by a freely selectable peel angle between the printed sheet (8) and the sheet receiving device (2).
The sheet paper reversing method according to claim 1, wherein the sheet is guided upward. 5. Separation between a printed sheet and a sheet receiving device based on a freely selected law of motion of the printed sheet (8) with respect to the oscillating movement of the sheet receiving device (2). Guided on a trajectory (13) located in the envelope bounded by a vector when the angle is between -10 ° and + 10 °.
The method for reversing the described sheet paper. 6. The track (13) of the printed sheet (8) is formed by a guide blade (9) arranged behind the tangent point (t _{1; 4} ) in the sheet feed direction. And the device. 7. A printed sheet (8) is continuously received from a storage drum (4) in a movement path of a swingable sheet receiving device (2) based on a known law of movement for realizing a small acceleration. A guide blade (9) for guiding in the movement path has a reversing drum (1) and a storage drum (4).
Envelope which is arranged immediately after the common tangent point (t _{1; 4} ) with and the guide surface (10) of the guide blade (9) is bounded by a vector when the peeling angle is -10 ° to + 10 °. A device which is arranged within a range (15 ° -5 °, 15 ° + 5 °). 8. The shape of the guide surface (10) of the guide blade (9) when the law of motion for the swinging motion of the sheet receiving device (2) is freely selected, and the peeling angle is 0 °. Device according to claim 6 or 7, characterized in that it corresponds to the envelope (15) formed by the vector. 9. The device according to claim 6, wherein the guide surface comprises a straight line portion and a circular arc portion. 10. The starting tangent range (10.1) and the sheet receiving device (2) with respect to the tangent point (t _{1; 4} ) of the guide surface (10) between the storage drum (4) and the reversing drum (1). End tangent range (10.
Device according to claim 6 or 7, characterized in that it comprises 3) and an arcuate range (10.2) connecting the starting tangent range and the ending tangent range. 11. Device according to claim 10, characterized in that the starting tangent range (10.1) or the ending tangent range (10.3) is part of an arcuate range (10.2). 12. The swing motion range of the sheet receiving device (2) is 50 to 70 with respect to the rotation angle α of the reversing drum (1).
8. An angle of °, characterized in that
The described device. 13. Device according to claim 7, characterized in that the sheet receiving device (2) is a suction device. 14. The starting tangent range (10.1) of the guide surface (10) of the guide blade (9) with respect to the common tangent point (t _{1; 4} ) of the storage drum (4) and the reversing drum (1). Device according to claim 9, characterized in that it is arranged tangentially or substantially tangentially. 15. A tangent to a storage drum, the starting tangent area (10.1) of a guide surface (10) of a guide blade (9) of which is arranged at a common tangent point (t _{1; 4} ) in the sheet feed direction. 10. Device according to claim 9, characterized in that it is arranged tangentially or approximately tangentially with respect to the point. 16. The guide blade (9) has an arcuate area (1).
0.2) and the end tangent range (10.3) and is formed as a pneumatic guide blade with pneumatic guide means (12) for guiding the sheet to the guide surface (10). 7. The apparatus of claim 6 characterized.