JP4177497B2 - Plate feeding mechanism of a rotary stencil printing press - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary stencil printing press, and more particularly to a plate feeding mechanism of a rotary stencil printing press.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a rotary stencil printing machine using a roll stencil sheet has been provided. In this type of rotary stencil printing machine, it is conceivable to make the stencil sheet thin for the purpose of, for example, improving the plate-making (printing) accuracy and reducing the replacement frequency of the stencil sheet roll.
[0003]
However, if the stencil sheet becomes thin and soft, it is easily affected by environmental conditions.For example, when the stencil sheet is loaded, the leading edge of the stencil sheet rolls up against the platen roller due to static electricity, etc. Trouble may occur. Should such a trouble occur in the platen roller, it is necessary to make it easy for the user to recover.
[0004]
Further, if the stencil sheet becomes thin and soft, wrinkles are likely to occur when the stencil sheet is loaded. Furthermore, if a thin stencil sheet is kept sandwiched between the platen roller and the thermal head for a long time, the stencil sheet may be partially deformed, or may be adversely affected by being in close contact with the platen roller or the thermal head. There is.
[0005]
[Problems to be solved by the invention]
Therefore, the technical problem to be solved by the present invention is to provide a plate feeding mechanism of a rotary stencil printing press that can use a thinner stencil sheet.
[0006]
[Means for solving the problems and actions / effects]
In order to solve the above technical problem, the present invention provides a plate feeding mechanism of a rotary stencil printing press having the following first configuration.
[0007]
The plate feeding mechanism of the rotary stencil printing machine has a thermal head in which a thermal head is disposed on the lower side and a platen roller is disposed on the upper side across the stencil sheet conveyance path, and the plate is made by passing between the thermal head and the platen roller. In a stencil feeding mechanism of a rotary stencil printing machine that supplies a stencil base paper
The platen roller is supported by a rotating member configured to be pivotally supported by a drive shaft positioned on the plate cylinder side of the thermal head so that the platen roller can be opened upward. The rotation is transmitted from the drive shaft to the platen roller via a belt . In the above configuration, the drive shaft may be a drive shaft of a base paper transport roller that transports base paper, which is different from the platen roller.
[0008]
According to the above configuration, when the platen roller is opened upward, the user can easily see the platen roller and can easily access the platen roller. Therefore, in the event of a trouble such as the stencil sheet being rolled up on the platen roller, the user can easily perform a recovery operation such as removing the stencil sheet wound around the platen roller.
[0010]
According to the above configuration, it is possible to expose the thermal head at the same time that the rotating member is rotated to open the platen roller upward. Therefore, operations such as cleaning the thermal head disposed below the stencil sheet conveyance path are facilitated.
[0011]
By the way, when the drive transmission system to the platen roller is cut off when the rotation member is rotated and the platen roller is opened upward, for example, when the rotation member is closed, the drive gear in the fixed position In the configuration in which the gears of the platen roller and the platen roller mesh with each other, backlash (backlash) increases in order to properly mesh the gears, and as a result, a problem occurs when the stencil sheet is made. Further, when the rotation member is closed and the drive transmission system is connected, there is a possibility that the crests of the gears may hit each other, and a complicated mechanism is necessary to avoid this reliably.
[0013]
According to the above configuration, the drive transmission system between the drive shaft and the platen roller is not cut off even if the rotation member is rotated. Therefore, since there is no problem in connecting the drive transmission system, the mechanism is simple, and the platen roller can be rotated without backlash during plate making.
[0014]
Preferably, a thermal head contact / separation mechanism that contacts and separates the thermal head with respect to the platen roller, and a thermal head retraction control unit that controls the operation of the thermal head contact / separation mechanism are further provided. The thermal head retracting control means operates the thermal head contact / separation mechanism so that the thermal head is separated from the platen roller when the rotating member is opened and / or closed.
[0015]
According to the above configuration, when the rotating member is opened and / or closed, the thermal head is retracted from the set position biased toward the platen roller, and the stencil sheet is placed between the thermal head and the platen roller. It is possible to prevent an undue force from acting on the stencil sheet when the rotating member is opened and closed so as not to be pinched. Also, when the rotating member is opened, the thermal head pushes up the platen roller, for example, it becomes difficult to release the setting position locking means of the rotating member, or when the rotating member is closed, the platen roller hits the thermal head strongly, etc. The problem can be avoided.
[0016]
The present invention also provides a plate feeding mechanism of a rotary stencil printing press having the following second configuration.
[0017]
The plate feeding mechanism of the rotary stencil printing machine has a thermal head in which a thermal head is disposed on the lower side and a platen roller is disposed on the upper side across the stencil sheet conveyance path, and the plate is made by passing between the thermal head and the platen roller. This is a type in which a stencil paper is supplied to a plate cylinder. The plate feeding mechanism of the rotary stencil printing machine includes a thermal head contact / separation mechanism that contacts and separates the thermal head with respect to the platen roller, and a thermal head retraction control unit that controls the operation of the thermal head contact / separation mechanism.
[0018]
According to the said structure, a thermal head can be made to contact / separate with respect to a platen roller as needed. Therefore, it is possible to avoid adverse effects caused by continuing to hold the stencil sheet between the thermal head and the platen roller more than necessary, or by keeping the thermal head and the platen roller in pressure contact more than necessary.
[0019]
Preferably, the thermal head retraction control unit is configured to contact and separate the thermal head from the platen roller a plurality of times during conveyance of the stencil sheet when a stencil sheet is loaded between the thermal head and the platen roller. The thermal head contacting / separating mechanism is operated so as to repeat the above.
[0020]
According to the above configuration, after the stencil sheet is loaded, the thermal head repeatedly contacts and separates from the platen roller a plurality of times while the stencil sheet is transported, thereby changing the tension acting on the stencil sheet and extending the wrinkle of the stencil sheet. Can do.
[0021]
Preferably, the thermal head retraction control means operates the thermal head contact / separation mechanism so that the thermal head is separated from the platen roller during standby until the stencil sheet is made.
[0022]
According to the above configuration, the platen roller and the thermal head are separated from each other during standby until the stencil sheet is made. Accordingly, the stencil sheet is not adversely affected by being sandwiched between the platen roller and the thermal head for a long time. In addition, it is possible to avoid the occurrence of problems such as deformation of the platen roller due to pressure contact with the thermal head, or the platen roller and the thermal head being in close contact with each other and being difficult to separate.
[0023]
As described above, the plate feeding mechanism of the rotary stencil printing press having the above-described configuration has been improved so that a thinner stencil sheet can be used. However, the present invention is not limited to this, and it goes without saying that the effect of improvement can be obtained in the same manner when a conventional stencil sheet is used. The first and second configurations may be combined.
[0024]
The present invention also provides a rotary stencil printing press including a plate feeding mechanism having the above-described configurations.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a rotary stencil printing machine and its plate feeding mechanism according to an embodiment of the present invention will be described.
[0026]
The rotary stencil printing machine 10 is configured in substantially the same manner as a known rotary stencil printing machine except for the plate feeding mechanism.
[0027]
The plate feeding mechanism is configured as shown in FIG. That is, the roll-shaped stencil sheet (master) 2 is stored in a stencil sheet roll storage section provided in the printing machine main body, and its leading end is drawn out to the plate cylinder 15. A mark detection sensor 4 for reading a mark formed at an appropriate position of the stencil sheet 2 is disposed below the stencil sheet roll storage unit. A stencil sheet guide bar 5, fixed guide plates 12 and 14, a thermal head 30, an idle roller 7, and a tip detection sensor 6 are arranged below the conveyance path. A platen roller 20, a cutter 16, a first sponge roller 22, and a second sponge roller 24 are disposed on the upper side of the conveyance path.
[0028]
The rotation is directly transmitted to the first sponge roller 22 from a plate feed motor 72 (see FIG. 3) via a belt (not shown). Rotation is transmitted to the platen roller 20 from the drive shaft of the first sponge roller 22 via a belt (not shown). The rotation is transmitted to the second sponge roller 24 from the drive shaft of the first sponge roller 22 via a belt and a plate feed clutch 74 (see FIG. 3). The second sponge roller 24 can be rotated or stopped when the platen roller 20 and the first sponge roller 22 are rotated by fitting / removing the plate feeding clutch 74. The plate feed motor 72 outputs a rotation pulse proportional to the rotation angle in order to control the transport distance.
[0029]
The cutter 16 is a rotary blade and is rotatably held by the cutter holding unit 16x. The cutter holding unit 16x is reciprocally driven by a cutter motor 16a (see FIG. 3) in a direction crossing the stencil sheet conveyance path. Cutter stop position detection switches 16s and 16t for detecting the cutter holding unit 16x retracted from the stencil sheet conveyance path are provided on the operation side and the back side across the conveyance path. When the stencil sheet is cut, the cutter motor 16a is rotated forward, the cutter holding unit 16x is moved from the operation side to the back side, and when detected by the cutter stop position detection switch 16t on the back side, the cutter motor 16a is reversed to hold the cutter. The unit 16x moves to the operation side. When the cutter holding unit 16x is detected by the operation-side cutter stop position detection switch 16s, the cutter motor 16a, and thus the cutter holding unit 16x, stops.
[0030]
The platen roller 20 is supported by the upper cover 50. The upper cover 50 is supported so as to be rotatable coaxially with the rotation axis of the first sponge roller 22, and can be rotated to a substantially vertical position indicated by a chain line in FIG. The opening / closing of the upper cover 50 is detected by the upper cover opening / closing detection switch 8.
[0031]
Specifically, as shown in FIG. 4A, the release lever 52 protrudes from an opening 50 a provided in the upper part of the upper cover 50. A square shaft 54 is rotatably supported inside the upper cover 50. As shown in FIG. 4B, a release lever 52 is fixed at the center and hooks 58 are fixed at both sides. Yes. A spring 56 is attached to the square shaft 54 and is urged in the direction in which the hook 58 is engaged with the locking shaft 17 protruding from the main body of the printing press. When the release lever 52 is pushed against the urging force of the spring 56, the engagement between the hook 58 and the locking shaft 17 is released. At this time, the hook side of the upper cover 50 is lifted by a spring (not shown).
[0032]
When the upper cover 50 is opened, as shown in FIG. 2, the platen roller 20 is exposed at a position close to the height of the line of sight L of the operator M, and the operator M easily lifts the platen roller 20. Can be seen and accessed. Therefore, when the stencil sheet 2 is loaded or when a trouble such as the stencil sheet 2 being rolled up on the platen roller 20 occurs, the operator M can easily work at a position close to the height of the line of sight L. Further, since the opening angle of the upper cover 50 is as large as about 90 degrees, the thermal head 30 provided on the lower side of the stencil sheet conveyance path can be easily cleaned.
[0033]
The front end side of the upper cover 50 has a curved shape so that the stencil sheet 2 is along. Generation | occurrence | production of a chatter sound is prevented by making the stencil paper 2 follow this curved part more than predetermined length. That is, the stencil sheet guide bar 5 has an insertion angle with respect to the curved part of the stencil sheet 2 due to a decrease in the pull-out angle of the stencil sheet 2 when the remaining amount of the stencil sheet roll decreases by a certain amount, in other words, with respect to the curved part. Helps prevent contact length from becoming smaller.
[0034]
The thermal head 30 can be brought into and out of contact with the platen roller 20 by the thermal head contact / separation mechanism 32 shown in FIGS. The thermal head 30 approaches the plantain roller 20 when the stencil sheet 2 is stretched and when making the plate, but is separated from the platen roller 20 at other times.
[0035]
The thermal head 30 is attached to the holding member 34. The holding member 34 is rotatably supported by a support shaft 18 provided on the stencil sheet roll side from the thermal head 30. The support shaft 18 is fixed to the printing machine body. A spring (not shown) is attached to the support shaft 18, and as shown by an arrow 96 through the pressure member 35, the holding member 34 is counterclockwise, that is, the direction in which the thermal head 30 approaches the platen roller 20. Has come to be energized. On the plate cylinder side of the holding member 34, an engagement piece 34a protrudes.
[0036]
A drive member 44 is disposed on the plate cylinder side adjacent to the holding member 34. The drive member 44 is rotatably supported on the plate cylinder side by a support shaft 19 fixed to the printing apparatus main body. An engagement piece 44a is provided on the stencil sheet roll side of the drive member 44 so as to project. A cam engagement hole 44 b is formed in the center of the drive member 44. The eccentric cam 42 is engaged with the cam engagement hole 44b, and the engagement piece 44a of the drive member 44 reciprocates one up and down by one rotation of the eccentric cam 42. As shown in FIG. 5, when the engagement piece 44 a of the drive member 44 is positioned on the upper side, the engagement piece 44 a of the drive member 44 is separated from the engagement piece 34 a of the holding member 34. On the other hand, as shown in FIG. 6, when the engagement piece 44 a of the drive member 44 is positioned on the lower side, the engagement piece 44 a of the drive member 44 pushes down the engagement piece 34 a of the holding member 34 from above, and the thermal head 30. Is separated from the platen roller 20, and a gap G is formed between them.
[0037]
The eccentric cam 42 is eccentrically fixed to the output shaft 41 of the thermal head contact / separation gear motor 40 (see FIG. 3). In order to detect the position of the eccentric cam 42, and hence the position of the thermal head 30, a half-moon shaped light shielding plate 36 is fixed to the output shaft 41 of the thermal head contact / separation gear motor 40, and the light shielding plate 36 is opposed to the light shielding plate 36. A thermal head contact / separation position detection sensor 38 as a sensor is disposed.
[0038]
Next, the configuration of the control system will be described with reference to FIG.
[0039]
A CPU 80 that controls the entire apparatus includes an operation panel 70 for an operator to give instructions, a ROM 82 for storing a control program, a RAM 84 for temporarily storing data, and as will be described later. An EEPROM 86 that stores the number of stop counters for stopping the front end of the stencil sheet at the reference position W is connected. Further, the CPU 80 includes a thermal head 30, a thermal head contact / separation gear motor 40, a plate feed motor 72, a cutter motor 16a, cutter stop position detection sensors 16s and 16t, an upper cover open / close detection switch 8, and a master. A reset switch 9, a plate feed clutch 74, a mark detection sensor 4, a tip detection sensor 6, a thermal head contact / separation position detection sensor 38, and the like are also connected.
[0040]
Next, operations and operations will be described.
[0041]
As shown in FIG. 2, the upper part 11 of the printing machine main body is opened and the stencil sheet 2 is loaded. The roll-shaped stencil sheet 2 is inserted into a stencil sheet roll storage section of the printing machine body. Then, as shown in FIG. 1, the upper cover 50 is opened, the front end side of the stencil sheet 2 is pulled out, passed through the tunnel-shaped stencil sheet front end holding portion 13 provided on the fixed guide plate 12, and lifted by the curl. While holding down, the top end of the stencil sheet 2 is aligned with the set position S, that is, the end of the thermal head 30 on the plate cylinder side, and then the upper cover 50 is closed. When the upper cover 50 is closed, the stencil sheet 2 is automatically conveyed. Then, when the leading edge of the stencil sheet 2 passes the leading edge detection sensor 6 and reaches the reference position W, the conveyance is temporarily stopped and waiting for the start of the plate making. That is, the front end of the stencil sheet 2 is positioned at the reference position W.
[0042]
At this time, if there is a defect such as wrinkles on the stencil sheet 2, the master reset switch 9 is pressed. Thus, after the cutter 16 cuts the stencil sheet 2, the stencil sheet 2 is conveyed together with the cut front end part by a predetermined distance until the rear end of the cut front end part passes through the first sponge roller 22. ,Stop. At that time, the second sponge roller 24 is stopped, and the cut tip side portion is not conveyed after the second sponge roller 24 and is between the first and second sponge rollers 22 and 24. At the same time, the panel display is a “master reset” warning display, and the operator opens the upper cover 50, removes the cut defective portion, rewinds the stencil sheet 2, and then moves the tip of the stencil plate to the stencil. The upper cover 50 is closed by passing through the base paper leading edge holding portion 13 to the set position S. When the upper cover 50 is closed, the stencil sheet 2 is automatically conveyed and stopped at a predetermined position.
[0043]
Next, the contact / separation operation of the thermal head 30 will be described.
[0044]
First, the contact / separation operation of the thermal head 30 immediately after the stencil sheet 2 is loaded will be described.
[0045]
As shown in the flowchart of FIG. 7, in step # 12, the process waits for the upper cover 50 to close. When the upper cover 50 is closed, in step # 14, the platen roller 20 and the first sponge roller 22 start to rotate, and in step # 16, the stencil sheet 2 waits for a predetermined distance (for example, 15 mm) to move. This is because the leading edge of the stencil sheet 2 is sufficiently separated from the gap 14a between the thermal head 30 and the fixed guide 14, and the leading edge of the stencil sheet 2 is not caught in the gap 14a by the subsequent contact / separation operation of the thermal head 30. It is to make it.
[0046]
When the leading edge of the stencil sheet 2 moves a predetermined distance, the thermal head contact / separation gear motor 40 rotates twice in step # 18. As a result, the thermal head 30 is brought into contact with and separated from the platen roller 20 twice, and the stencil sheet 2 being conveyed is stretched. Then, the thermal head 30 stands by at a position away from the platen roller 20 until plate making. When the leading edge of the stencil sheet 2 passes the leading edge detection sensor 6 and reaches the reference position W, the conveyance of the stencil sheet 2 is stopped.
[0047]
At the time of plate making, the thermal head contact / separation gear motor 40 rotates 1/2. As a result, the thermal head 30 comes close to the platen roller 20, that is, the thermal head 30 comes into sliding contact with the stencil sheet 2. As in the conventional apparatus, the thermal head 30 makes the stencil sheet 2 in synchronization with the movement of the stencil sheet 2. A portion of the stencil sheet 2 that has been made is made into a predetermined length by a cutter 16 and wound around a plate cylinder 15.
[0048]
Next, the contact / separation operation of the thermal head 30 after plate making will be described.
[0049]
As shown in the flowchart of FIG. 8, in step # 22, the completion of the stencil stencil sheet wrapping is waited. When the winding is completed, the platen roller 20 and the first sponge roller 22 start to rotate in step # 24, and wait for the tip of the stencil sheet 2 to move from the cutter 16 by a predetermined distance (for example, 5 mm) in step # 26. This is because the front end of the stencil sheet 2 is sufficiently separated from the cutter hole 14b of the fixed guide plate 14 so that the front end of the stencil sheet 2 is not caught in the cutter hole 14b by the subsequent contact / separation operation of the thermal head 30. is there.
[0050]
When the leading edge of the stencil sheet 2 moves a predetermined distance, the thermal head contact / separation gear motor 40 rotates twice in step # 18. As a result, the thermal head 30 comes in contact with and separates from the platen roller 20 twice to stretch the stencil sheet 2. Then, with the thermal head 30 separated from the platen roller 20, it waits until the next plate making. When the leading edge of the stencil sheet 2 reaches the reference position W, the platen roller 20 and the first sponge roller 22 stop rotating.
[0051]
As described above, the wrinkle of the stencil sheet 2 can be extended by repeating the contact / separation operation of the thermal head 30 with respect to the plantain roller 20 a plurality of times before making the stencil sheet 2.
[0052]
Further, since the thermal head 30 stands by in a state of being separated from the platen roller 20 until the plate making, unnecessary pressure does not act on the stencil sheet 2. Accordingly, since the stencil sheet 2 is not partially deformed and does not come into close contact with the platen roller 20 or the thermal head 30, troubles such as the stencil sheet 2 being wound around the platen roller 20 can be avoided. . Further, since the pressure on the platen roller 20 is also released, the platen roller 20 can be prevented from being deformed. Furthermore, since the thermal head 30 and the platen roller 20 can be separated from each other, the thermal head 30 and the platen roller 20 are not in close contact and difficult to separate.
[0053]
In addition, this invention is not limited to the said embodiment, It can implement in another various aspect.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a plate feeding mechanism of a rotary stencil printing press according to the present invention.
FIG. 2 is a perspective view of a rotary stencil printing machine of the present invention.
FIG. 3 is a block diagram of a control system of a rotary stencil printing press according to the present invention.
FIG. 4 is a detailed view of an upper cover.
FIG. 5 is a configuration diagram of a thermal head driving mechanism. The thermal head is in the approach position.
6 is a configuration diagram similar to FIG. The thermal head is in the retracted position.
FIG. 7 is a flowchart of a thermal head contact / separation operation. It shows immediately after loading stencil paper.
FIG. 8 is a flowchart similar to FIG. It shows after the first plate making.
[Explanation of symbols]
2 stencil sheet 4 mark detection sensor 5 stencil sheet guide bar 6 leading edge detection sensor 7 idler roller 8 upper cover open / close detection switch 9 master resetting switch 10 rotary stencil printing machine 11 upper part 12 fixed guide plate 13 stencil sheet leading edge holding part 14 fixed Guide plate 14a Clearance 14b Cutter hole 15 Plate cylinder 16 Cutter 16a Cutter motor 16s, 16t Cutter stop position detection switch 16x Cutter holding member 17 Lock shaft 18 Support shaft 19 Support shaft 20 Platen roller 22 First sponge roller 24 Second sponge roller 30 Thermal head 32 Thermal head contact / separation mechanism 34 Holding member 34a Engagement piece 35 Pressurizing member 36 Light shielding plate 38 Thermal head contact / separation position detection sensor 40 Thermal head contact / separation gear motor 41 Output shaft 42 Eccentric cam 44 Drive member 4a engaging piece 44b cam engaging hole 50 on the cover (rotating member)
50a Opening 52 Release lever 54 Square shaft 56 Spring 58 Hook 70 Operation panel 72 Plate feed motor 74 Plate feed clutch 80 CPU (thermal head retraction control means)
82 ROM
84 RAM
86 EEPROM
90 to 96 Arrow G Gap L Eye M Operator S Set position W Reference position

Claims (5)

A thermal head (30) is disposed on the lower side and a platen roller (20) is disposed on the upper side across the stencil sheet conveyance path, and the plate is passed between the thermal head (30) and the platen roller (20). In the stencil feeding mechanism of the rotary stencil printing machine (10) for feeding the heat-sensitive stencil sheet (2) to the plate cylinder (15),
The platen roller (20) is pivotally supported coaxially with a drive shaft located closer to the plate cylinder (15) than the thermal head (30) so that the platen roller (20) can be opened upward. The rotating member (50) configured to be capable of being supported so as to come into contact with and separate from the thermal head (30) , and that rotation is transmitted from the drive shaft to the platen roller (20) via a belt. A plate feeding mechanism of a rotary stencil printing machine.   2. The plate feeding mechanism of a rotary stencil printing press according to claim 1, wherein the drive shaft is a drive shaft of a base paper transport roller that transports base paper, which is different from the platen roller. A thermal head contact / separation mechanism (32) for contacting and separating the thermal head (30) with respect to the platen roller (20);
Thermal head retraction control means (80) for controlling the operation of the thermal head contact / separation mechanism (32),
The thermal head retraction control means (80) is configured so that the thermal head (30) is separated from the platen roller (20) when the rotating member (50) is opened and / or closed. The plate feeding mechanism of a rotary stencil printing press according to claim 1 or 2 , wherein the thermal head contacting / separating mechanism (32) is operated. A thermal head contact / separation mechanism (32) for contacting and separating the thermal head (30) with respect to the platen roller (20);
2. The plate feeding mechanism of a rotary stencil printing press according to claim 1, further comprising a thermal head retraction control means (80) for controlling the operation of the thermal head contact / separation mechanism (32).   A rotary stencil printing press comprising the plate feeding mechanism of the rotary stencil printing press according to any one of claims 1 to 4.

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