JPS63306043A - Raw paper clamp for stencil printer - Google Patents

Abstract

PURPOSE:To effectively hold raw paper in a simple structure by disposing the end of a movable clamping piece at the rocking end side at the preceding side of a plate cylinder in its rotating direction and a rocking axial center at the following side of the cylinder, and passing the route of the paper held between both clamping faces radially inward of the cylinder with respect to the rocking axis. CONSTITUTION:Raw paper is held between a clamping plate 4 and a clamping base 5, a plate cylinder 1 is further rotated from this state, the paper 16 is bent at a point P1 of the end corner of a rubber magnet plate 9 and a point P2 of the end corner of the plate 4, extended rearward of its rotating direction along the upper end face of the plate 4, and further bent at a point P3 of the corner of 1 cutout 7. The paper 16 passed through the point P3 is further extended rearward of the rotating direction, and bonded to the outer periphery of the plate 3, but passed through the inside from the center Pc of a rocking axis 6, i.e., radially inward of the plate 1. Accordingly, the tension for pulling the paper 16 rearward in the rotating direction generates a moment of the direction for pressing the plate 4 to the base 5 around the center Pc of the axis 6.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a base paper locking device for a stencil printing machine, and more particularly to a base paper locking device that has a fixed clamp surface and a movable clamp piece on the outer peripheral surface of a rotating printing plate cylinder, and clamps one end of the base paper between them. This relates to a stop device.

[Prior art]

Generally, in a rotary stencil printing machine, a printing plate is formed by pasting base paper on the outer peripheral surface of a rotating drum-shaped printing cylinder. One end of the base paper is fixed onto the outer circumferential surface of the plate cylinder, and a base paper locking portion is formed on the outer circumferential surface of the plate cylinder as a structure for this purpose. As one of the prior art closest to the present invention, the base paper locking device constituting this base paper locking portion is based on Utility Model Application Publication No. 61-9324.
Clamp type devices are known, which are described in Japanese Utility Model Publication No. 1 or Japanese Utility Model Application Publication No. 61-31830. These clamp-type base paper locking devices have a fixed clamp surface extending along the axial direction on the outer peripheral surface of the drum-shaped plate cylinder, and a fixed clamp surface that is designed to clamp one end of the base paper between the fixed clamp surface and the outer peripheral surface of the drum-shaped plate cylinder. A movable clamp piece that opens and closes is formed opposite to this fixed clamp surface. In addition, in any paper locking device, the tip of the movable clamp piece is located on the following side with respect to the rotational direction of the plate cylinder, while the pivot support, which is the center of swing of the movable clamp piece, is located on the plate cylinder rotation direction. It is located on the leading side in the direction of rotation of the barrel. Therefore, when pasting the base paper on the outer peripheral surface of the plate cylinder, the plate cylinder rotates with one end of the base paper being clamped by this base paper locking device, and the base paper is locked in the forward direction of rotation, that is, in the forward direction. The device is positioned behind it, and the base paper follows and is successively attached to the outer circumferential surface of the plate cylinder.

[Problems to be solved by the invention]

By the way, when printing with a rotary stencil printing machine, a frictional force acts between the plate surface and the printing surface, and this frictional force causes the base paper to rotate while attached to the outer circumferential surface of the plate cylinder. being pulled backwards. Also, when attaching the base paper to the outer circumferential surface of the plate cylinder, be careful not to wrinkle the base paper.
Rotate the plate cylinder while pulling the base paper backwards. This tensile force causes the base paper to ``displace'' on the outer circumferential surface of the plate cylinder.
In extreme cases, there is a risk that the held portion may come off the base paper locking device. Conventional clamp-type base paper locking devices have a structure in which the movable clamp piece opens and closes toward the side that follows the rotational direction of the plate cylinder, that is, toward the rear, which can cause the base paper to become "misaligned" or fall off from the clamp part. The structure is such that it is difficult to generate a force that opposes the rearward pulling force that causes it. The present invention has been devised in view of the above problems and to effectively solve them. Therefore, the object is to provide a base paper locking device for a stencil printing machine that can securely clamp the base paper and prevent the base paper from being "misaligned" or falling off from the clamp section.

[Means to solve the problem]

A base paper locking device for a printing press according to the present invention has the following configuration in order to solve the problems of the prior art and achieve the objectives. That is, a fixed clamp surface extends along the axial direction of the drum-shaped printing plate cylinder on the outer circumferential surface of the drum-shaped printing plate cylinder, and a fixed clamp surface that faces the fixed clamp surface so as to be pressed against the fixed clamp surface; a movable clamp piece that has a swing axis along the axial direction of the plate cylinder and is swingable around the swing axis, and a swinging tip side end of the movable clamp piece rotates when the plate cylinder rotates. On the direction leading side, the swing axis is located on the rotation direction following side of the plate cylinder, and the base paper, whose one end is held between the movable clamp piece and the fixed clamp surface, is closest to the swing axis. A path passing through the plate cylinder is configured to pass radially inward of the plate cylinder with respect to the swing axis. Note that the fixed clamp surface is fixed compared to the movable clamp piece that can swing, but the state in which it is attached to the plate cylinder does not need to be firmly fixed, and some "backlash" is acceptable. be done.

[Effect]

According to the base paper locking device for a printing press according to the present invention, when the base paper is fed and stuck to the outer peripheral surface of the plate cylinder, the part of the base paper that is clamped between the movable clamp piece and the fixed clamp surface is placed first. and is sent in a direction opposite to the direction of rotation of the plate cylinder. The movable clamp piece faces in the direction of rotation of the plate cylinder and its tip is open. The leading end of the fed base paper is inserted between the opened movable clamp piece and the fixed clamp surface. When the leading edge of the base paper is inserted, the movable clamp piece is closed and the plate cylinder rotates further. As the plate cylinder continues to rotate in this state,
The base paper is inverted so as to be folded back along the tip of the movable clamp piece, and further extends beyond the upper end surface of the movable clamp piece to the rear in the direction of rotation of the plate cylinder, and is pasted onto the outer peripheral surface of the plate cylinder. A tensile force acts on the base paper to pull it backwards in the direction of rotation of the plate cylinder, but most of this tensile force acts on the movable clamp piece at the inverted and folded part, and the paper is pulled between the movable clamp piece and the fixed clamp. The force that attempts to pull out one end of the base paper held between the surfaces is attenuated to a very small force. Since the path through which the base paper reversed at the tip of the movable clamp piece passes inside the swing axis of the movable clamp piece, that is, inside the plate cylinder in the radial direction, the force that pulls the base paper backward in the rotational direction is A moment is generated about the axis in a direction that presses the movable clamp piece against the fixed clamp surface. This moment acts equally over the entire width of the base paper. Furthermore, the stronger the pulling force, the greater the moment generated, and the base paper is reliably clamped between the movable clamp piece and the fixed clamp surface.

【Effect of the invention】

As is clear from the above description, the present invention provides the following excellent effects. That is, the base paper can be reliably held with a simple structure.

【Example】

A preferred embodiment of the present invention will be described below with reference to FIGS. 1 to 8.
This will be explained with reference to the figures. FIG. 1 is a perspective view showing a plate cylinder in which a base paper locking device for a stencil printing machine according to the present invention is employed. The direction of rotation of the plate cylinder l in the figure is the direction of arrow R. A protruding strip 2 projecting outward in the radial direction in a bank-like manner is formed on the peripheral edge portions at both ends of the plate cylinder 1. The main components of the clamp section 3 as a paper locking device are a clamp base 5 as a fixed clamp surface and a clamp plate 4 as a movable clamp piece. The opening/closing operation of the clamp unit 3 is performed by the clamp plate 4 swinging and engaging/disengaging from the clamp base 5, but the opening/closing portion is connected to the plate cylinder 1.
facing forward in the direction of rotation. That is, the front end 19 of the closed clamp plate 4 is located on the leading side in the rotational direction of the plate cylinder l. The clamp stand 5 is formed by bending a substantially rectangular thin plate made of a magnetic material such as a steel plate so as to follow the outer circumferential surface of the plate cylinder I, and the clamp table 5 is formed by bending a substantially rectangular thin plate made of a magnetic material such as a steel plate so as to follow the outer circumference of the plate cylinder I between the convex stripes 2. It is fixed on the surface so as to extend along its axial direction. The clamp plate 4 is pivotally supported on the outer circumferential surface of the convex strip 2 via a swing shaft 6 at both ends thereof. The shape of the clamp plate 4 is such that the central part along one long side of the rectangular shape has a notch 7 that is slightly longer than the width of the base paper.
The swing shaft 6 is provided to protrude in the longitudinal direction at both ends along the long side including the notch 7. A torsion spring 8 is provided on the swing shaft 6 to bias the clamp plate 4 in the opening direction. On the other hand, a rubber magnet plate 9 is attached to the surface of the clamp plate 4 facing the clamp base 5 side. The elastic force of the torsion spring 8 is extremely weak and cannot prevent the force of the clamp plate 4 from adhering to the rubber magnet plate 9 (clamp base 5). It is hardly involved in setting the condition, and acts during the plate discharging operation described later.As a means for driving the opening/closing operation of the clamp plate 4, a lever member 2 is fixed to one end of the swing shaft 6. A handle-like bottle portion 12 is provided protruding from the tip of the lever member 11. On the other hand, a pin portion 12 of the lever member 11 is attached to a fixed portion IO such as a frame of the printing press body. An arm member 13 that rotates the clamp plate 4 together with the arm member 13 is pivotally supported.
The opening/closing operation is controlled by 1. FIGS. 2 and 3 are schematic diagrams showing the relationship between the base paper locking device of the present invention attached to the plate cylinder, the plate feeding roller, and the plate discharging roller, respectively. The direction of rotation of the plate cylinder l is in the direction of arrow R. 15 is a plate feeding roller, and 14°, 14'' is a plate discharging roller. The position where the plate feeding operation is performed is the A position in FIG. 2, and the position where the plate discharging operation is performed is the B position. Therefore, the above-mentioned The arm member 13 that operates the opening/closing operation of the clamp plate 4 is provided at two positions, A position and B position.First, the plate feeding operation will be explained.The plate cylinder l rotates and the clamp part 3 is moved to the A position. At this point, the clamp section 3 is opened, and the base paper 16 is sent out from the plate feeding roller 15 and inserted between the clamp plate 4 and the clamp stand 5. When the base paper 16 is inserted, as shown in FIG. Then, the clamp section 3 is closed again and the base paper is clamped between the clamp plate 4 and the clamp base 5. From this state, the plate cylinder l continues to rotate, and the base paper 16 is moved along the tip of the clamp plate 4. The plate is then turned over so as to be folded back, and is then pasted onto the outer peripheral surface of the plate cylinder l, passing over the upper end surface of the clamp plate 4. Fig. 4 is an enlarged schematic diagram showing the state in which the original paper is locked in the clamp part. Below is the fourth
The state of each force acting on the base paper 16 and the clamp section 3 will be described in detail with reference to the drawings. A magnetic attraction force is generated between the rubber magnet plate 9 of the clamp plate 4 and the clamp stand 5 while the base paper 16 is being clamped therebetween. The base paper 16 is bent at a point P1 at the tip corner of the rubber magnet plate 9, further bent at a point P at the tip corner of the clamp plate 4, and rotated along the upper end surface of the clamp plate 4 in the rotational direction (of the plate cylinder l). ) extends rearward and is further bent at a point P3 at the corner of the notch 7. The base paper 16 that has passed through point P further extends rearward in the rotational direction and is attached to the outer peripheral surface of the plate cylinder l, but passes inside the center Pc of the swing shaft 6, that is, inside the plate cylinder l in the radial direction. . Therefore, the tensile force F that pulls the base paper 16 backward in the rotational direction generates a moment around the center Pc of the swing shaft 6 in a direction that presses the clamp plate 4 against the clamp base 5. Moreover, this moment acts uniformly over the entire width of the base paper 16. Furthermore, the stronger the tensile force F is, the greater the moment is generated, and the base paper 16 is reliably clamped between the clamp plate 4 and the clamp stand 5. Further, the tensile force F is applied to the base paper 16 at the point P1. By being bent at Pt and Ps, a force acting on the corners of the clamp plate 4 at each bending point, and a force trying to pull it out is applied to the portion held between the clamp plate 4 and the clamp base 5. It hardly works. Next, the master discharge operation will be explained. When the plate cylinder I rotates and the clamp part 3 reaches position B in FIG. 2, the clamp part 3 is opened by a lever member (not shown) and an arm member (not shown). The plate discharge rollers 14° and 14'' correspond to the B position of the clamp section 3, and when the clamp section 3 at the B position swings the clamp plate 4, the upper end surface (back surface) of the clamp plate 4 is aligned with the plate discharge rollers 14', 14. ” lower roller 14
The respective rollers 14' and 14'' are arranged inside and outside the swing radius of the clamp plate 4 so as to be in contact with the upper roller 14'' but not with the upper roller 14''. Figure 5 (1) to 5
Up to Figure (5), the clamp plate 4 and base paper 1 in the plate discharge operation are shown.
6 is a schematic diagram showing a series of operations of the plate discharge rollers 14', 14'' and the plate cylinder l.The clamp plate 4 swings toward the open side at the B position, and the base paper 16 is stacked on its upper end surface (back side). As it is, it is pressed together with the original paper 16 by the lower roller 14'' of the discharge roller 14°, 14''. This pressing force is not so large and is due to the resilient urging force of the torsion spring 8 attached to the swing shaft 6 mentioned above. Therefore, there is "play" in the engagement between the arm member 13 that swings the clamp plate 4 and the lever member 11, and this "play" occurs when the clamp plate 4 is in contact with the lower roller 14'. Because of this, the spring force of the torsion spring 8 acts to press the clamp plate 4 against the lower roller 14'. When the clamp plate 4 is pressed by the lower roller 14°, the base paper 16 becomes slack on the back side of the clamp plate 4, so the force (rotation) in the direction in which the lower roller 14' tries to wind up the base paper 16 is force), and is wound up between the upper roller 14'' and the lower roller 14°. When the base paper 16 is completely clamped between both rollers 14' and 14'', the clamp plate 4 It is closed again and the base paper 16 is separated from the clamp section 3. Finally, as the plate cylinder l rotates, the plate discharge rollers 14' and 14'' also rotate and the base paper 16 is discharged.Here, when the clamp plate 4 is pressed by the lower roller 14', the clamp plate 4 The base paper 16 may loosen on the back side of the
This is a necessary condition for reliably winding the base paper 16 between the upper roller 14'' and the lower roller 14'.
Some examples will be shown below as means for ensuring that 6 is loosened. In FIG. 6, when the clamp plate 4 is pressed by the lower roller 14', the lower roller 14'' slightly rotates in the opposite direction to the winding rotation direction, thereby loosening the base paper 16. In FIG. , the needle 17 is attached to the rubber magnet plate 9 of the clamp plate 4.
By attaching a needle 17 to the base paper 16 and making the base paper 16 follow the swinging motion of the clamp plate 4, the base paper 16 is loosened. In FIG. 8, when the clamp plate 4 swings in the opening direction at the master discharge position, a rod member 18 that engages with the original paper 16 on the back side of the clamp plate 4 to ensure its slack is abbreviated as a swing shaft 6. installed in parallel. This rod member 18 is biased in the direction of arrow T with a biasing force that is sufficiently weaker than the pressing force between the clamp plate 4 and the lower roller 14. When no tensile stress is applied to the base paper 16, a position where the base paper 16 becomes slack is secured. Further, when the plate discharge rollers 14° and 14'' try to wind up the base paper 16 between them, this bar member 18 moves toward the lower roller 14° according to the tensile force acting on the base paper 16, and the bar member 18 rarely generates a force that resists the entrainment force.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a plate cylinder in which a base paper locking device of a stencil printing machine according to the present invention is adopted, and FIGS. 2 and 3 respectively show the base paper locking device of the present invention attached to the plate cylinder. A schematic diagram showing the relationship between the plate feeding roller and the plate discharge roller. Figure 4 is an enlarged schematic diagram showing the state in which the base paper is locked to the clamp section. Figure 5 is the clamp plate, base paper, and master discharge roller in the plate discharge operation. and a schematic diagram showing a series of operations of the plate cylinder,
FIGS. 6 to 8 are schematic diagrams each showing a modification of the means for loosening the base paper during the master discharge operation.

Claims (1)

[Claims] (1) A fixed clamp surface (5) extending along the axial direction of the drum-shaped printing plate cylinder (1) on the outer peripheral surface of the printing plate cylinder (1).
), and a swinging shaft (6) facing the fixed clamping surface (5) and extending along the axial direction of the plate cylinder (1) so as to be pressed against the fixed clamping surface (5). It has a movable clamp piece (4) that can swing around a moving shaft (6), and the swinging front end (19) of the movable clamp piece (4) is arranged in the direction of rotation of the plate cylinder (1). On the leading side, the swing shaft (6) is located on the rotation direction following side of the plate cylinder (1), and one end is connected to the movable clamp piece (4) and the fixed clamp surface (5).
) The path through which the base paper (16) sandwiched between A base paper locking device for a stencil printing machine, characterized in that it is configured to pass through.