JPH04224950A - Sheet-fed press with reversal mechanism - Google Patents

Abstract

PURPOSE:To obtain a sheet-fed press with a reversal mechanism capable of saving labor required for phase adjustment work between a reversing cylinder and a feed cylinder following the change of sheet size by performing the phase adjustment work during printing operation suspension using a motor and a speed reduction mechanism in a state where the pressing action by a pressing mechanism is released. CONSTITUTION:While printing operation is underway, the clutches 76, 77 of a reduction gear are set so that a motor 61 becomes engaged with a feed cylinder 11 at an equal speed. In addition, the clutches 76, 77 disengages the pressing mechanism with an annular gear so that the pressing action is released under a suspended printing operation during phase adjustment. The clutches are switched from equal speed to reduced speed and the motor 61 is driven with a braking mechanism 60 activated to perform phase adjustment between the reversal cylinder 13 and the feed cylinder 11. Subsequently, the phase adjustment work is labor-saved and the working time is shorted.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-fed printing press with a reversing mechanism, and more particularly to an improvement for simplifying the work involved in changing the phase of a reversing cylinder.

0002

2. Description of the Related Art A sheet-fed printing press with a reversing mechanism is capable of single-sided printing and double-sided printing, and various types have been put into practical use. As an example, FIG.
, will be explained with reference to FIG.

FIG. 7 shows the case of single-sided printing, in which the plate cylinder (
An impression cylinder 5 is provided obliquely below the blanket cylinder 1, which is in contact with the blanket cylinder 1 below (not shown), with its circumferential surface facing the blanket cylinder 1. A claw 4 for gripping the starting end of the paper is provided in the notch on the outer periphery of the impression cylinder 5. A blanket cylinder 6 is also provided on the opposite side of the double diameter cylinder 12 so as to be in contact with a plate cylinder (not shown), and an impression cylinder 10 equipped with a pawl 9 is in contact with this blanket cylinder 6. It is provided. A reversing mechanism is provided between the impression cylinders 5 and 10, and includes a transfer cylinder 11, a double diameter cylinder 12, and a reversal cylinder 13 whose peripheral surfaces are in contact with each other. The transfer drum 11 is provided with a claw 16 in a notch on its outer periphery. The double diameter barrel 12 is
It has a diameter double that of the transfer drum 11, and claws 19 and 20 are provided at opposing positions on the outer periphery in the diametrical direction. Double diameter barrel 12
Suction heads 21 and 2 are provided on the outer periphery behind the claws 19 and 20 in the direction of rotation, and at positions facing each other, are suction heads 21 and 2 for suctioning the beginning or end of the paper by air suction.
2 are arranged. A plurality of these suction heads 21 and 22 are arranged in parallel in the direction of the rotation axis of the double diameter cylinder 12, and
It is configured to be movable in the circumferential direction so that the phase with respect to the claws 19, 20 can be adjusted. In the outer peripheral notch of the reversing cylinder 13, claws 25 and 28 are arranged adjacent to each other in the circumferential direction.

[0004] Rubber cylinders 1, 6, impression cylinders 5, 10, transfer cylinder 11
, the double diameter cylinder 12, and the reversing cylinder 13 are connected so as to be driven by gears attached to their respective rotation shafts. At the end of the rotating shaft of the reversing cylinder 13, a fixed gear (not shown) that is fixed to the shaft and a rotary gear (not shown) that is rotatable are provided so that they can be fixed to and released from each other. It meshes with the gear on the barrel 10, and the rotation gear meshes with the gear on the double diameter barrel 12. With this configuration, in the case of single-sided printing, each cylinder is
The starting end of the paper 30 fed from the paper feeding device (not shown) is gripped by the claw 4 of the impression cylinder 5. Printing is performed on the paper 30 when it passes between the blanket cylinder 1 and the impression cylinder 5, and is conveyed while being gripped by the claws 16 of the transfer cylinder 11. The paper 30 is further transported from the claw 16 of the transfer drum 11 to the claw 19 (20) of the double diameter drum 12, and as shown in the figure, the claw 19 and the claw 25 are opposed to each other, so that the paper 30 is conveyed.
It is then carried in a bag. Paper 30 on reversing cylinder 13
is held in the claw 9 of the impression cylinder 10, and the rubber cylinder 6 and the impression cylinder 1
0, the second color is printed on the same surface of the paper 30 as the first color.

When transitioning from single-sided printing to double-sided printing, the state in which the claws 19 and 25 correspond to each other in FIG.
The aforementioned rotary gear is rotated so that the suction head 21 and the claw 28 are in a corresponding state as shown in FIG. By this, the phase of the upstream cylinder group including the double diameter cylinder 12 is adjusted with respect to the reversal cylinder 13, and the claws 19 and 2 on the double diameter cylinder 12 are adjusted in phase.
0 and the suction heads 21 and 22 to cope with changes in paper size. In addition, the claws 19 and 2 of the double diameter barrel 12
Since the position at which 0 releases the paper 30 in its grip differs by approximately the length of the paper 30 in the vertical direction between single-sided printing and double-sided printing, the operating position of the paper release cam (not shown) is adjusted.

After performing the switching adjustment in this way, when each cylinder is rotated, the paper 30 printed on the front side in the same manner as in the case of single-sided printing will have its starting edge aligned with the claw 19 (20) of the double-diameter cylinder 12.
), and the end is attached to the suction head 21 (22
) and then transported. Then, as indicated by 30A in the figure, the cylinder is conveyed until the end reaches the contact point between the double diameter cylinder 12 and the reversing cylinder 13. At this time, the opening and closing of the claw 28 and the suction head 21
Immediately after gripping the end of the paper 30A by suction and release, the claws 20 release the grip while blowing out compressed air from the suction head 21 to promote separation of the paper. transported. During this conveyance, the claws 25 and 28 open and close at different timings, and the paper 30A is transferred from the claws 28 to the claws 25 and transferred. When the claw 25 and the claw 9 of the impression cylinder 10 face each other, the paper 30A
is held in the claw 9 and conveyed as shown by 30B in the figure. When the paper 30B passes between the blanket cylinder 6 and the impression cylinder 10, printing is applied to the back side of the paper 30B, and the above-mentioned printing on the front side results in double-sided printing and the paper is discharged.

[0007]

SUMMARY OF THE INVENTION In such a sheet-fed printing press with a reversing mechanism, the following manual operations are required when switching between single-sided printing and double-sided printing, as described above. This will be explained with reference to FIG. In Figure 9, the transfer drum 1
1. The double diameter cylinder 12 and the reversing cylinder 13 are drivingly connected by a transfer cylinder gear 112, a double diameter cylinder gear 122, and a reversing cylinder gear 132, which are fixed to one end of the rotating shafts 111, 121, 131, respectively. Strictly speaking, the reversing barrel gear 132 is capable of transmitting rotational driving force via the ring gear 133, and this means that the ring gear 133 is connected to the reversing barrel gear 132 by a disc 134 bolted to the reversing barrel gear 132. This is achieved by press-contacting the A scale indicating the phase is engraved on the ring gear 133, and a pointer corresponding to the scale is engraved on the disc 134. Therefore, by loosening the bolt (not shown) on the disc 134, the connection between the reversing barrel 13 and the double diameter barrel 12 can be released. Rotating shafts 111, 121,
131 are each pivotally supported by the main body frame 100. Further, a phase adjustment gear (not shown) is meshed with the transfer barrel gear 112, and a hand handle is fixed to the phase adjustment gear via a clutch and a speed reducer. When performing phase adjustment, after the connection between the reversing cylinder 13 and the double diameter cylinder 12 is released as described above, the clutch connected to the hand handle is engaged and the hand handle is turned.

However, in such a position adjustment mechanism,
When adjusting the phase by turning the hand handle, it was difficult to check the scale because the position at which the hand handle was turned was far from the position at which the scale was used to check the amount of phase adjustment. Moreover, when the hand handle is turned, all the gears on the hand handle side are rotated, and the claws 16, 4, etc. that hold the paper in their mouths are opened and closed, making turning the hand handle very heavy and labor intensive. Such work not only takes a long time, but also requires a great deal of labor. In view of these problems, an object of the present invention is to provide a sheet-fed printing press with a reversing mechanism that can save labor in phase adjustment work and shorten working time.

[0009]

[Means for Solving the Problems] The present invention includes a reversing cylinder and a feeding cylinder, and a reversing cylinder gear and a feeding cylinder gear are respectively fixed to the shaft ends of these cylinders, and the outer circumferential step of one gear is fixed to the shaft end of each of these cylinders. In a sheet-fed printing machine with a reversing mechanism, a sheet-fed printing machine with a reversing mechanism is provided with a pressing mechanism that presses the annular gear against the one gear while the annular gear is in mesh with the other gear. The most upstream side (or the most downstream side) with respect to the flow of
A brake mechanism is provided on the cylinder located upstream (or downstream) of the reversing cylinder on the most downstream side (or most upstream side) to prevent its rotation, and The cylinder is equipped with a motor for driving the printing press, and this motor and the cylinder are connected via a speed reduction mechanism that can be switched between constant speed and deceleration using a clutch. The present invention is characterized in that the phase adjustment work is performed by the motor and the speed reduction mechanism in a state where the pressing by the pressing mechanism is released. According to the present invention, the present invention also includes a reversing cylinder and a feeding cylinder, a reversing cylinder gear and a feeding cylinder gear are respectively fixed to the shaft end of each of these cylinders, and an annular gear is fixed to the outer circumferential step of one gear. In a sheet-fed printing press with a reversing mechanism, the press mechanism presses the annular gear against the one gear while the annular gear is in mesh with the other gear, the most upstream side with respect to the flow of paper. A phase adjustment motor is provided in a cylinder located upstream (or downstream) of the reversing cylinder (or the most downstream side), and a clutch is used to connect the phase adjustment motor and the cylinder to the cylinder. The cylinder located downstream (or upstream) of the most downstream (or most upstream) reversing cylinder is equipped with a brake mechanism for driving the printing press. A motor is provided, and the phase adjustment work when the printing operation is stopped is performed by connecting the phase adjustment motor to the cylinder at the upstream position via the clutch-equipped deceleration mechanism in a state where the pressing by the pressing mechanism is released. A sheet-fed printing press with a reversing mechanism is obtained.

0010

[Operation] In the first invention, the clutch of the reducer is set to connect the motor and the feed cylinder at a constant speed while printing is being performed. When adjusting the phase, the pressing mechanism is released from the annular gear when the printing operation is stopped, the clutch is switched from constant speed to deceleration, and the motor is driven with the brake mechanism activated to control the reversing cylinder and the feeding cylinder. Adjust the phase between. In the second invention, the clutch-equipped speed reduction mechanism is set to keep the phase adjustment motor disconnected from the feed cylinder while the printing operation is being performed. During phase adjustment, the pressure of the pressing mechanism against the annular gear is released while the printing operation is stopped, the phase adjustment motor is connected to the feed cylinder by a clutch-equipped reduction mechanism, and the phase adjustment motor is driven. Adjusts the phase with the feed cylinder.

[0011]

Embodiment FIG. 1 shows a schematic configuration of a sheet-fed printing press with a reversing mechanism according to a first embodiment of the present invention, which has one combination of a reversing cylinder and a double diameter cylinder as shown in FIG. . The paper is shown in Figure 7.
Since the flow flows from the right side to the left side in the diagram, which is different from FIG. . The rotation of the cylinder placed upstream of the reversing cylinder 13 (in this embodiment, the transfer cylinder 11-1 in contact with the most upstream double-diameter cylinder 12-1) is controlled as necessary (during phase adjustment). A brake mechanism 60 is provided to prevent this. On the other hand, the reversing cylinder 13
A cylinder placed further downstream (in this embodiment, the most downstream double-diameter cylinder 12-5) is equipped with a motor 6 with a brake for driving the printing press.
1, and a deceleration mechanism 7 capable of switching between constant speed and deceleration between the motor 61 and the double diameter cylinder 12-5 using a clutch.
Connected via 0. The speed reduction mechanism 70 will be described in detail later. The rotating shaft or barrel gear of the barrel downstream of the reversing barrel 13 (in this embodiment, the rotating shaft or the reversing barrel gear of the reversing barrel 13) is provided with an encoder for detecting its rotation angle during phase adjustment work. 62 is provided, and the operation of the motor 61 for phase adjustment is controlled based on the detection signal of the encoder 62. In the embodiment described above, the motor 61 with a brake for driving the printing press is connected to the reversing cylinder 1.
Although it is provided on the downstream side with respect to 3, it may be provided on the upstream side with respect to the reversing cylinder 13. In this case, the brake mechanism 60 is provided downstream with respect to the reversing cylinder 13, and the encoder 6
It goes without saying that 2 is provided on the rotating shaft of the cylinder including the reversing cylinder 13 and on the upstream side of the cylinder or the cylinder gear. Also,
In the case of a printing press equipped with a plurality of sets of reversing cylinders 13, the motor 61 with a brake for driving the printing press is connected to a cylinder located downstream (upstream position) of the reversing cylinder 13 on the most downstream side (most upstream side). The brake mechanism 60 is provided on the most upstream side (most downstream side)
The encoder 62 is installed on a cylinder located upstream (downstream position) from the reversing cylinder 13 of installed in the gear.

FIG. 2 shows an example of the speed reduction mechanism 70.
Fourth gears 71 to 74 and first and second clutches 76, 7
7 are arranged in the coushing 75 so as to constitute a constant speed and deceleration mechanism. The first gear 71 is fixed via a sleeve 78 to an end of a rotating shaft 100-2 that is rotatably supported by the main body frame 100. And the rotating shaft 100-
2, a gear 100-3 is fixedly installed, and the gear 100-3 meshes with the double diameter barrel gear 122-5. The second and third gears 72 and 73 are fixed to both sides of a rotating shaft 80 whose both ends are supported by bearings 79 and 79 provided within the casing 75. The second gear 72 meshes with the first gear 71, and the third gear 73 meshes with the fourth gear 74. The fourth gear 74 is supported via a bearing 82 on a rotating shaft 81 supported by the casing 75 so as to be concentric with the rotating shaft 121-4. The first clutch 76 is
An electromagnetic attraction mechanism 76-1 attracts and separates from the attraction target plate 78-1, which is integrated with the sleeve 78. Note that the adsorption mechanism 76-1 includes an electromagnet 76- fixed to the casing 75.
The suction plate 76-1b is configured to rotate together with the rotating shaft 81 relative to the suction plate 76-1a. The second clutch 77 also
Similar to the clutch 76, an electromagnetic attraction mechanism 77-
1 is attracted to and separated from the attraction plate 83 that is integrally assembled to the fourth gear 74, and the attraction mechanism 77-1 attracts the attraction plate 7 to the electromagnet 77-1a fixed to the casing 75.
7-1b is configured to be rotatable together with the rotating shaft 81. A pulley 83 is provided at the end of the rotating shaft 81 protruding from the casing 75, and a belt 8 is connected between this pulley 83 and a pulley (not shown) provided on the output shaft of the motor 61.
4 will be bridged.

Next, the operation will be explained. During printing operation, the first clutch 76 in the speed reduction mechanism 70 is turned on and the second clutch 77 is turned off, and the rotational force from the motor 61 is passed through the belt 84, the rotating shaft 81, and the first clutch 76 to the rotating shaft 100-2. introduce. In this case, the second
The fourth gears 72 to 74 become idle. The brake mechanism 60 is not operated and the detection signal from the encoder 62 is not used. When performing phase adjustment, the brake mechanism 60 is operated while the motor 61 is stopped, and the ring gear 133 shown in FIG. 9 is released from the reversing barrel gear 132. Then, in the speed reduction mechanism 70, the first clutch 76 is turned off and the second clutch 77 is turned on, and the motor 61 is reversed to transfer the rotational force of the rotating shaft 81 to the second clutch 77, the fourth clutch 77, the fourth clutch 77, and the third clutch 77.
, second and first gears 74, 73, 72, 71 to reduce the speed and transmit it to the rotating shaft 100-2. The rotation of the double diameter cylinder 12-5 is transmitted to the reversing cylinder 13 via each cylinder, but since the double diameter cylinder 12-3 does not rotate, phase adjustment is performed. At this time, the rotation angle of the reversing cylinder 13, that is, the phase between the reversing cylinder 13 and the double diameter cylinder 12-3 is detected by the encoder 62, and this detected value is displayed on a display (not shown). The operator turns on the motor 61 while looking at this display.
Do off. Of course, the phase adjustment amount is set in advance with the setting device, and the set phase adjustment amount and the encoder 62
An automatic adjustment method may be adopted in which the phase is automatically adjusted while comparing the detected value with the detected value. When the phase adjustment is completed, the bolts on the disc 134 are tightened so as to press the ring gear 133 against the reversing barrel gear 132 again. Then, the operation of the brake mechanism 60 is released.

The second invention will be explained with reference to FIGS. 3 to 6. In FIG. 3, the combination of the cylinders of this invention is the same as in FIG. The transfer drum 11-1) is provided with a phase adjustment motor 63, and the transfer drum 11-1 and the phase adjustment motor 63 can be connected via a clutch-equipped speed reduction mechanism 90. On the other hand, a cylinder downstream of the reversing cylinder 13 (in this embodiment, the most downstream double diameter cylinder 12-5) is provided with a motor 61 with a brake for driving the printing press. The rotating shaft or barrel gear of the barrel upstream of the reversing barrel 13 (in this embodiment, the rotating shaft or double diameter barrel gear of the double-diameter barrel 12-3) has its rotation angle adjusted during phase adjustment. An encoder 62 for detection is provided, and the operation of the phase adjustment motor 63 is controlled based on the detection signal of the encoder 62. In this embodiment, the phase adjustment motor 63 is provided upstream of the reversing cylinder 13;
It may also be provided on the downstream side. In this case, the motor 61 with a brake mechanism for driving the printing press is installed on the upstream side of the reversing cylinder 13, and the encoder 62 is installed on the rotating shaft or cylinder gear of the cylinder including the reversing cylinder 13 and downstream thereof. Needless to say. In addition, in the case of a printing press equipped with a plurality of sets of reversing cylinders 13, the phase adjustment motor 63 is located at an upstream position (downstream position) from the most upstream (most downstream) reversing cylinder 13.
The motor 61 with a brake mechanism is installed in the cylinder located downstream (upstream position) of the reversing cylinder 13 on the most downstream side (most upstream side), and the encoder 62 is installed on the cylinder placed on the most downstream side (most upstream side). It is provided on the rotating shaft or cylinder gear on the upstream side (downstream side) of the reversing cylinder (most upstream side). The clutch-equipped speed reduction mechanism 90 is housed in a casing 91 fixed to the main body frame 100, as shown in FIGS. 4 to 6. That is, a reducer 92 is fixed with bolts inside a casing 91, and a first rotary shaft 93, which is rotatable together with the reducer and slidable in the axial direction, is attached to one rotating shaft 93 of the reducer.
A second gear 94A is provided by spline fitting, and a second gear 94B is provided via a bearing 95. The first gear 94A can mesh with and be separated from the second gear 94B by sliding. The second gear 94B is
Transfer drum gear 1 attached to the rotating shaft of transfer drum 11-1
It meshes with 11-1. A gear 96 is attached to the other rotating shaft of the reducer 92 and meshes with a pinion 65 attached to the rotating shaft of the phase adjustment motor 63.

As shown in FIGS. 4 and 6, the first gear 94A is connected to the cylinder 97, the connecting rod 98, the arm 99, and the first gear 94A.
It is slidably driven by a drive mechanism in combination with a ring R1 fitted to the outer periphery of the gear 94A. cylinder 97
is fixed to the frame 100-1 and driven by air or oil pressure. Connecting rod 98 transmits the reciprocating motion of the piston within cylinder 97 to one end of arm 99 . The arm 99 includes an arm 99-2 connecting the tip of the connecting rod 98 and a supporting rod 99-1 pivotally supported by the casing 91, and an arm 99-2 connecting the supporting rod 99-1.
1 and two bolts 99-3A and 99-3B. The two bolts 99-3A and 99-3B are attached to the casing 91
Holes R1-A, R1- provided in ring R1 through
They are screwed into B. The first gear 94A and the second gear
An extension spring S1 is installed between the first gear 94A and the second gear 94B via a bearing B1 to bias the first gear 94A away from the second gear 94B.

Next, the operation will be explained. During printing operation, the clutch in the reduction mechanism 90 is in the first gear 94A.
and the second gear 94B are in a disconnected state, and the phase adjustment motor 63 is also stopped. That is, the speed reduction mechanism 90
The piston in the cylinder at is in the position that has moved to the farthest left in FIG.
4A is separated from the second gear 94B. At this time, the second gear 94B is in an idle state. The bearing B1 is provided to prevent the extension spring S1 from being worn out due to this idling. When performing phase adjustment, the motor 61 is stopped to function as a brake mechanism, and the ring gear 133 shown in FIG. 9 is released from the reversing barrel gear 132. In the reduction mechanism 90, the cylinder 9
7, the first gear 94A is moved to the left in FIG. 5 via the connecting rod 98, arm 99, and ring R1, thereby meshing with the second gear 94B. Next, the phase adjustment motor 63 is activated and the rotational force is transmitted to the transfer body gear 111-1 via the pinion 65, gear 96, reduction gear 92, and second gear 94B. The rotation of the transfer cylinder gear 111-1 is transmitted to the double diameter cylinder 12-3 via each cylinder. On the other hand, the double diameter cylinder 12-5 of the reversing cylinder 13 is prevented from rotating by the motor 61 functioning as a brake mechanism, thereby adjusting the phase between the double diameter cylinder 12-3 and the reversing cylinder. The control of the phase adjustment amount may be the same as the method described in the first invention. In addition, in both the first and second inventions, by using a speed reduction mechanism in which the speed reduction ratio can be adjusted in multiple stages, the accuracy of the phase adjustment amount can be improved.

[0017]

As explained above, according to the present invention, power for rotating the reversing cylinder or double diameter cylinder can be obtained from the motor during phase adjustment, thereby reducing the labor and effort required for phase adjustment. The time can be significantly reduced.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the schematic configuration of a first aspect of the present invention.

FIG. 2 is a sectional view showing the internal structure of a clutch-equipped speed reduction mechanism, which is a main part of the first invention.

FIG. 3 is a diagram for explaining a schematic configuration of a second aspect of the present invention.

FIG. 4 is a sectional view showing the internal structure of a clutch-equipped speed reduction mechanism, which is a main part of the second invention.

FIG. 5 is a sectional view taken along line AA in FIG. 4;

6 is a sectional view taken along line BB in FIG. 4. FIG.

FIG. 7 is a diagram for explaining the single-sided printing operation of a sheet-fed printing press with a reversing mechanism.

FIG. 8 is a diagram for explaining the double-sided printing operation of a sheet-fed printing press with a reversing mechanism.

FIG. 9 is a diagram for explaining the connection relationship between the double diameter cylinder, the reversing cylinder, and the transfer cylinder.

[Explanation of symbols]

11　　　　Intermediate body 12 Double diameter barrel 13 Inversion trunk 60 Brake mechanism 61　　　　Printing machine drive motor 62 Encoder 63 Phase adjustment motor 70　　　Deceleration mechanism with clutch 90 Reduction mechanism with clutch

Claims (4)

[Claims] [Claim 1] Includes a reversing cylinder and a feeding cylinder, a reversing cylinder gear and a feeding cylinder gear are respectively fixed to the shaft ends of these cylinders, and an annular gear is rotatably attached to an outer circumferential step of one of the gears. In a sheet-fed printing press with a reversing mechanism, which is equipped with a pressing mechanism that presses the annular gear against the one gear while the annular gear is in mesh with the other gear, the most upstream side (or Upstream position (most downstream side) from the reversing cylinder (most downstream side)
Alternatively, a brake mechanism is installed on the cylinder located downstream (or downstream position) to prevent its rotation, and the cylinder located downstream (or upstream) from the most downstream (or most upstream) reversing cylinder is used for printing. In addition to providing a motor for driving the machine, this motor and the cylinder are connected via a speed reduction mechanism that can be switched between constant speed and deceleration using a clutch. A sheet-fed printing press with a reversing mechanism, characterized in that the motor and the speed reduction mechanism perform printing in a state where pressing by the mechanism is released. 2. A sheet-fed printing press with a reversing mechanism according to claim 1, wherein rotation of cylinders downstream (or upstream) of the reversing cylinder including the most upstream (or most downstream) reversing cylinder; A sheet wafer with a reversing mechanism, characterized in that a rotation angle detector is provided on the shaft or body gear, and the phase adjustment operation is performed by controlling the motor based on the output signal of the rotation angle detector. Printer. [Claim 3] Includes a reversing cylinder and a feeding cylinder, a reversing cylinder gear and a feeding cylinder gear are respectively fixed to the shaft ends of these cylinders, and an annular gear is rotatably attached to an outer circumferential step of one of the gears. In a sheet-fed printing press with a reversing mechanism, which is equipped with a pressing mechanism that presses the annular gear against the one gear while the annular gear is in mesh with the other gear, the most upstream side (or Upstream position (most downstream side) from the reversing cylinder (most downstream side)
Alternatively, it is possible to provide a phase adjustment motor in the cylinder located in the downstream position, and to connect the phase adjustment motor and the cylinder with a clutch-equipped speed reduction mechanism that can be connected to and disconnected from the cylinder using a clutch. and the position downstream (or upstream) of the reversing cylinder on the most downstream side (or most upstream side)
A motor with a brake mechanism for driving the printing press is installed on the cylinder placed in the cylinder, and when the printing operation is stopped, the phase adjustment work can be performed by rotating the phase adjustment motor with the clutch equipped with a deceleration mechanism when the pressing mechanism releases the pressure. A sheet-fed printing press with a reversing mechanism, characterized in that the printing machine is connected to the cylinder at the upstream position via a mechanism. 4. A sheet-fed printing press with a reversing mechanism according to claim 3, wherein rotation of cylinders upstream (or downstream) of the reversing cylinder including the most downstream (or most upstream) reversing cylinder; A reversing mechanism characterized in that a rotation angle detector is provided on the shaft or body gear, and the phase adjustment operation is performed by controlling the phase adjustment motor based on the output signal of the rotation angle detector. Sheet-fed printing press.