JPH0416375A - Platen supporting device for printing machine - Google Patents

Abstract

PURPOSE:To make a platen supportable and releasable positively by a method wherein the platen is held in the operating position with a bearing being pressed by a cam surface of a lever through on energizing member, and the bearing is released with the lever turned while resisting against the energizing force. CONSTITUTION:A platen 2 is mounted on a supporting frame 3 and is held in the operating position with a bearing 14 fitted into a notch 19 of the supporting frame 3 and being pressed with a cam surface 26 through an energizing member 27. When dismounting the platen 2 held in the operating position from the notch 19 of the supporting frame 3, a lever 21 is turned while resisting against the energizing force, and the cam surface 26 on the front end thereof is allowed to be detached from the bearing 14, and thereby the platen 2 is released from the supporting frame 3. Thereby the platen 2 can be held firm in the operating position and can be made detachable from that position.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a platen support device for a printing device, particularly a plate-making/printing type mimeograph printing machine.

BACKGROUND OF THE INVENTION FIG. 1 shows a typical mimeograph machine of the type described above, in which the platen support device of the present invention is installed. read by CCD 9 with optical system, roll master 1
A thermal head 11 makes a plate by perforating the base paper 15 that is supplied from scratch. The base paper made in this way is wound around the drum 1, and ink is supplied from the ink device 12 inside the drum 1 to seep out from the back side of the base paper 15, and the paper feed roller 5 and registration roller 6 are used to remove the ink from the paper feed tray 7. The image is transferred onto the transported paper 16 by the press roller 4.

In the printing machine as described above, the thermal head 1
A platen 2 is used to bring the base paper 15 into close contact with the base paper 15, and as shown in FIG. The bearing plate 17 is fitted into and supported by a notch 19 of a bearing plate 17 attached to the support frame 3, and is also attached by a threaded rod 18 screwed into the support frame 3.

Problems to be Solved by the Invention However, in the above-described printing press, when replacing or cleaning the thermal head 11, the platen 2 must be removed, and at that time the threaded rod 18 must be turned by hand. The operation is troublesome because the threaded rod 1
If the threaded rod 8 is tightly tightened, it will be difficult to turn it by hand, and if the threaded rod 18 is weakly tightened to avoid this, there is a problem that it will naturally loosen due to the vibrations that occur during plate making and printing. .

An object of the present invention is to solve the problems of the conventional platen support device as described above, and to provide a platen support device that is easy to operate, does not require special operating force, and can support the platen reliably. There is something to do.

Means for Solving the Problems In order to achieve the above-mentioned objects, the present invention attaches a lever rotatably to a support frame, forms a cam surface at the tip of the lever, and attaches the lever to the support frame. A biasing member is provided, and the cam surface presses the bearing member by the biasing force of the biasing member to hold the platen in the operating position, and by rotating the lever against the biasing force of the biasing member. , characterized in that the bearing member is shaped to release the bearing member.

The platen shaft adjacent to the bearing member is supported by a lift arm rotatably attached to the support frame, and this lift arm is linked to a lever, so that when the lever releases the bearing member, the lift arm holds the platen shaft. It is supposed to be raised.

Function: In the platen support device of the present invention, when removing the platen held in the operating position from the notch of the support frame, the lever is rotated against the biasing force of the biasing member. The cam surface at the tip is separated from the bearing member to release the platen from the support frame.

Conversely, after fitting the bearing member into the notch of the support frame,
By pressing the cam surface at the tip of the lever against the bearing member by the urging force of the urging member, the platen is mounted on the support frame and held in the operating position.

In order to remove the platen from the support frame as described above, when the lever is rotated, the lift arm attached to the support frame moves in conjunction with the lever to lift the platen shaft and remove the platen from the notch in the support frame to the outside. taken out.

Embodiments In the embodiments of the present invention shown in FIGS. 1 to 7,
The same reference numerals are used for the same parts as in the conventional example.

The upright portion 23 and the horizontal portion 2 are located on the open side of the notch 19 of the bearing 14 fitted into the notch 19 of the bearing plate 17.
A branch base of a substantially inverted T-shaped lever 21 having 4 and 4 is rotatably attached to the support frame 3 by a shaft 22.

A cam surface 2 is provided at the end of the horizontal portion 24 facing the bearing 14.
6 is formed, and its rear end is constantly under tension by a tension spring 27 stretched between it and the support frame 3. Cam surface 26
As shown in FIG. 4, it has a circular arc shape centered on the center O1, which is located horizontally backward from the center of the shaft 22, and its radius is equal to the distance between the center O1 and the center O2 of the bearing 14. This is the distance between the intersection P of the connecting line and the outer periphery of the bearing 14 and the center 01. In this position, the lever 21 is
7 gives a tendency to rotate clockwise around the axis,
This causes the cam surface 26 to press the bearing 14 within the notch 19 and hold the platen 2 in the operating position.

In such a position, it has an opposing surface 28 facing the platen shaft 13 on the opposite side to the cam surface 26, and the headed shaft 2
A lift arm 31 is rotatably attached to the support frame 3 by 9, and a wave washer 34 is interposed on the opposite side of the head of the headed shaft 29 of the lift arm 31 (FIG. 3). The wave washer 34 forces the lift arm 31 against the head of the headed shaft 29 with friction.

This lift arm 31 has an approximately triangular through hole 32.
is provided, and a pin 33 provided near the cam surface 26 of the lever 21 passes through this through hole 32. The through hole 32 is shaped to have the function described later.

The effects of the above will be explained.

2 to 4 show that the lever 21 is given a clockwise rotational tendency by the spring 27 as described above, and the cam surface 26 presses the bearing 14 against the notch 19 of the bearing plate 17, thereby causing the platen to rotate. 2 is held in the operating position. In this case, the platen 2 will receive a reaction force in the direction shown by the arrow A from the thermal head 11, but the platen 2 will try to move due to this reaction force, and the lever 21 will be moved clockwise via the bearing 14 and the cam surface 26. When the lever 21 attempts to rotate, the lever 21 rotates in a direction in which the radius of the cam surface 26 increases, resulting in the cam surface 26 biting into the bearing 14, which causes the platen 2 to wobble. It will be supported by the support frame 3 without any movement.

In this case, the pin 33 of the lever 21 engages with the front corner of the through hole 32 and holds the lift arm 31 in a position where the facing surface 28 faces the platen shaft 13.

The platen 2 held in this way is supported by the support frame 3.
When removing the lever 21 from the lever 21, as shown by arrow B in FIG.
3 and rotates counterclockwise, the cam surface 26 separates from the bearing 14 as shown in FIG. At the same time, the pin 33 moves to the rear corner of the through hole 32, and this movement causes the lift arm 31 to rotate clockwise about the shaft 29, and the opposing surface 28 moves the platen shaft 13 to the surface of the notch 19. Move it diagonally upward along.

When the pressing action on the lever 2 is stopped, the lever 21 is pulled by the spring 27 and rotates in the opposite direction clockwise as shown in FIG. , and moves the platen shaft 13 upward along the opposing surface 28. In this case, the pin 33 moves to the front corner of the inclined through hole 32. In this way lever 2
When + moves from the position shown in the fifth figure to the position shown in the sixth figure,
Due to the frictional force of the wave washer 34, the lift arm 31 does not move regardless of the movement of the pin 33.
The situation remains the same.

As this state progresses further, the bearing 14 moves outward from the notch 19 and is held by the tip of the cam surface 26 and the tip of the bearing plate 7, as shown in FIG. In this state, the platen 2 can be easily taken out.

At this time, the pin 33 moves to the front corner of the through hole 32 and returns the lift arm 31 to its original holding position (FIG. 4).

When reattaching the platen 2 to a device from which the platen 2 has been removed in this way, move the platen shaft 13 and bearing 14 again to the position shown in FIG. rotates counterclockwise, and when the bearing 14 is fitted into the notch 19, the spring 27
The tensile force causes the cam surface 26 of the lever 21 to press against the bearing 14 to hold the platen 2 in the operating position.

Effects of the Invention The present invention is as described above, and the platen is moved by pressing the cam surface of the lever rotatably attached to the support frame against the bearing member by the biasing force of the biasing member provided on the support frame. The operation is simple because the platen is held in the operating position and the cam surface is separated from the bearing member against the biasing force of the biasing member to release the platen.
This has the advantage that the platen can be reliably held in or released from the operating position without requiring special operating force.

In addition, the platen shaft adjacent to the bearing member is supported by a lift arm that is rotatably attached to the support frame and is provided in conjunction with the lever, so when the lever is rotated to release the platen. Another effect is that the lift arm cooperates with the lever to lift the platen out of the support frame, making it easier to remove the platen.

[Brief explanation of the drawing]

Fig. 1 is a schematic front view of a printing press equipped with a platen support device of the present invention, Fig. 2 is a perspective view of an embodiment of the invention, Fig. 3 is a plan view of a portion of the above, and Fig. 4 is the same as the above. FIG. 5 is a drawing similar to FIG. 4 showing the initial state of the platen release work, FIG. 6 is a similar drawing showing a state further advanced than the previous one, and FIG. 7 8 is a similar drawing showing the final state when the platen is released, and FIG. 8 is a perspective view of a typical example of a conventional platen support device. 2...Platen 11...Thermal head 14...Bearing 17...Bearing plate 2I...Lever 23...Upright portion 26...Cam surface 28...Opposing surface 3...Support Frame 13...Platen shaft 15...Base paper 19...Notch portion 22...Shaft 24...Transverse portion 27...Tension spring 3I...Lift arm Fig. 2 Fig. 1 Fig. 3

Claims (1)

[Claims] 1. Bearing members are rotatably attached to both ends of the platen shaft,
In a printing machine in which the platen is attached by fitting the bearing member into a notch provided in the left and right support frames, a lever is rotatably attached to the support frame, a cam surface is formed at the tip of the lever, and a cam surface is formed at the tip of the lever. is provided with a lever biasing member, and the cam surface is driven by the biasing force of the biasing member.
The platen is held in the operating position by pressing the bearing member, and the bearing member is released by rotating the lever against the biasing force of the biasing member. platen support device. 2. The platen shaft adjacent to the bearing member is supported by a lift arm rotatably attached to the support frame, and this lift arm is linked to a lever, so that when the lever releases the bearing member, the lift arm supports the platen shaft. 2. The platen support device for a printing press according to claim 1.