JP2002052767A - Paper feed mechanism of dot line printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an adjustment work in consequence of replacing consumable parts and facilitate the adjustment work itself by constituting a unit itself inexpensively. SOLUTION: In one representative example, two shaft guides 7 and 8 formed of sliding members are clamped on a paper feed frame 11 while being positioned to grooves of the paper feed frame 11 on circumferences of rotation centers of a drive shaft 5 and a guide shaft 6. In a state while assembled, tractors 4, the drive shaft 5, the guide shaft 6, and both shaft guides 7 and 8 are made separable from the paper feed frame 11 in a direction of opening parts of the grooves.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a paper feed mechanism for a dot line printer.

[0002]

2. Description of the Related Art FIGS. 3 and 4 show a prior art.

The printing method of the dot line printer is such that the print hammer 1 is reciprocated in the direction perpendicular to the paper feed direction by a shuttle mechanism (not shown), and the print hammer 1 is driven via the ink ribbon 2 in this process. Prints characters, figures, and the like on the printing paper 3 in the form of a dot matrix.

[0004] The printing paper 3 is fed at appropriate times by a paper feed mechanism. The paper feed mechanism also serves as a pair of tractors 4 for transporting the printing paper 3, a drive shaft 5 for driving the tractor 4, a guide shaft 6 supporting the tractor 4, and bearings for the drive shaft 5 and the guide shaft 6. A tractor unit 15 in which a shaft guide (hereinafter referred to as an LH shaft guide) 7 and a shaft guide (hereinafter referred to as an RH shaft guide) 8 are assembled, and a platen 9 for holding a printing force of the printing hammer 1 is a platen frame 10. And a frame 11 that rotatably supports the platen unit about the drive shaft 5.

The platen unit is opened and closed about the drive shaft 5 around the drive shaft 5 when the paper is loaded or the like by an open mechanism using an open cam 12.
The gap (hammer gap) between the printing hammer 1 and the platen 9 is set to an initial value by an adjusting mechanism (not shown).
A lever (hereinafter referred to as FT cam) connected to an FT cam 12
(Referred to as a lever) 13.

In the prior art, two types of opening and closing mechanisms for opening and closing the platen unit and adjusting the hammer gap have been provided.

Further, the printing paper is pressed against the platen 9 by a thin plate spring 14 called a friction plate so as to prevent the settability from being disturbed by the shuttle operation, thereby maintaining the settability. The friction plate 14 is attached and adjusted to the front and rear with respect to the frame 11 to secure stabilization, and a pressing force (paper tension) against the platen 9 is used.
Was going to be adjusted. The pressing force has an appropriate value. If the pressing force is too weak, the settability is disturbed. If the pressing force is too strong, the transportability of the tractor 4 deteriorates. Therefore, the friction plate 14 is finely adjusted to satisfy both.

Since the platen unit is disposed on the frame 11 via the drive shaft 5, when exchanging parts on the platen unit such as the tractor 4 and the platen 9, which are consumable parts, the platen unit is connected to the frame 1
I was working down from one.

The paper feed mechanism in the prior art has a large number of components and accumulates tolerances in assembly, so that after replacing the tractor 4, the platen 9, etc., the adjustment values before assembly cannot be maintained. , Hammer gap, and paper tension must be readjusted.

[0010]

The paper feed mechanism of the prior art has a structure having two types of opening / closing mechanisms between the hammer platens, and has a large number of components and a high cost.

When replacing the components of the platen unit, the unit must be disassembled from the equipment, and since there are many components, tolerances in assembly are accumulated and adjustment values before assembly cannot be maintained. Hammer gap, and paper tension had to be readjusted.

Since the adjustment of the friction plate cannot be made long, the spring constant is high and the adjustment sensitivity is too high, so that fine adjustment work has been required.

[0013] Since the friction plate is attached to the frame, access to the friction plate involves opening and closing the platen unit, which has been a difficult adjustment.

SUMMARY OF THE INVENTION An object of the present invention is to provide a dot line printer in which the unit itself is inexpensively constructed, adjustment work for replacing consumable parts is reduced, and the adjustment work itself is simplified.

[0015]

In order to solve the above-mentioned problems, the LH shaft guide 7 and the RH shaft guide 8 which also serve as bearings are supported by the tractor 4, the guide shaft 6, and the drive shaft 5, and the drive is assembled. The tractor unit 15 is positioned in the groove of the frame 11 on the circumference of the rotation center of the shaft 5 and the guide shaft 6 and fastened on the frame 11, and the tractor unit 15 is moved in the direction of the opening of the groove.
So that it can be removed from

Further, both ends of the platen 9 are pushed into a pair of side guides 17 provided on the frame 11 so that the platen 9 can move in the printing force direction (the direction of the gap between the printing hammer 1 and the platen 9). The platen 9 is printed on the opening / closing cam 16 which is provided at both ends of the FT shaft 19 and is printed on the circumferential surface in accordance with the rotation angle and has a profile corresponding to the gap opening / closing amount between the hammer and the platen and the maintenance opening / closing amount. The spring 1 is brought into contact with the opposing surface of the force holding surface and pressurized on both the opening / closing cam 16 and the side guide 17.
8 and the FT shaft 1 connected to the opening / closing cam 16
9 are rotatably held on the paper feed frame 11 by the
By rotating the T shaft 19, the printing hammer 1
The distance between the platen 9 and the platen 9 is adjusted so that the assembly tolerance does not accumulate when the platen 9 is replaced.

Further, the friction plate 14 is fixed to the paper guide 20 extending from the paper insertion opening, and the paper insertion opening side of the paper guide 20 is rotatably held around the paper girder direction. Paper guide 2 against the side plate of frame 11
The thin plate spring is lengthened and the spring constant is set low to set the spring constant low, and the adjusting screw is accessed from both sides of the frame 11. It is good to

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings.

LH shaft guide 7, R also serving as bearing
H shaft guide 8 is connected to tractor 4, guide shaft 6,
In a state where the drive shaft 5 is supported and assembled, the drive shaft 5 and the guide shaft 6 are positioned in the U-groove of the frame 11 on the circumference of the center of rotation and fastened on the frame 11, and the tractor is moved in the direction of the opening of the U-groove. The unit 15 is configured to be detachable from the frame 11.

With the above-described configuration, replacement of the LH shaft guide 7 and the RH shaft guide 8 which also serve as the tractor 4 and the bearing, which are consumable parts, can be facilitated.
Further, since the hammer gap and the paper tension do not change with the replacement work, there is no need for the adjustment work.

Further, both ends of the platen 9 are protruded from a pair of side guides 17 provided on the frame 11 so that the platen 9 is movable in a printing force direction (a direction of a gap between the printing hammer 1 and the platen 9). The platen 9 is printed on the opening / closing cam 16 which is provided at both ends of the FT shaft 19 and is printed on the circumferential surface in accordance with the rotation angle and has a profile corresponding to the gap opening / closing amount between the hammer and the platen and the maintenance opening / closing amount. The spring 1 is brought into contact with the opposing surface of the force holding surface and pressurized on both the opening / closing cam 16 and the side guide 17.
8 and the FT shaft 1 connected to the opening / closing cam 16
9 are rotatably held on the paper feed frame 11 by the
By rotating the T shaft 19, the printing hammer 1
The distance between the platen 9 and the platen 9 is adjusted.

With the above-described configuration, if the accuracy of the components of the platen 9 itself is ensured, the number of connected components is small, and
Since the accumulated tolerance during assembly is small, it is not necessary to readjust the paper tension and the hammer gap when replacing the platen 9. Further, the platen unit and the opening and closing mechanism shown in the related art can be simplified, and the device can be configured at low cost.

Further, the friction plate 14 is fixed to the paper guide 20 extending from the paper insertion opening, and the paper insertion opening side of the paper guide 20 is rotatably held around the paper girder direction. Paper guide 2 against the side plate of frame 11
The thin plate spring is lengthened and the spring constant is set low to set the spring constant low, and the adjusting screw is accessed from both sides of the frame 11. To be configured.

According to this configuration, the spring constant of the friction plate 14, which is a thin plate spring, can be increased to reduce the spring constant, and the adjustment sensitivity corresponding to the amount of pressing against the platen 9 can be reduced. In addition, since the adjustment screws can be accessed from both sides of the frame 11, the platen unit can be opened and closed, and adjustment while accessing a narrow place can be facilitated.

[0025]

According to the present invention, the unit itself can be constructed at a low cost, the adjustment work accompanying replacement of consumable parts can be reduced, and the adjustment work itself can be facilitated.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing an embodiment of the present invention.

FIG. 3 is a perspective view showing a conventional technique.

FIG. 4 is a cross-sectional view showing a conventional technique.

[Explanation of symbols]

1: printing hammer, 2: ink ribbon, 3: printing paper, 4
... Tractor, 5 ... Drive shaft, 6 ... Guide shaft, 7 ... Shaft guide, 8 ... Shaft guide, 9 ... Platen, 10 ... Platen frame, 11 ... Frame, 1
2 cam, 13 lever, 14 friction plate, 15 tractor unit, 16 opening / closing cam, 17
Side guide, 18: spring, 19: shaft, 20: paper guide.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C058 AB05 AC03 AC12 AE03 AE09 AF26 AF31 DC02 DC07 DC09 DC22 DC23 EA02 EA15 EA17 EB03 EC03 2C060 BA12 BC85 3F104 FA07

Claims (3)

[Claims] 1. A tractor for intermittently feeding a sheet of paper as printing is performed in units of dot rows, and two shafts for holding the tractor, wherein one of the shafts holds the tractor. , The driving force of the motor is transmitted to the tractor, the other one holds the tractor and positions the tractor in the beam direction, and the tractor drive shaft and the guide shaft are connected to a shaft guide made of sliding members at both ends. A mechanism that is rotatably held and fastens the paper guide frame with the two shaft guides holding the tractor, the guide shaft, and the drive shaft; Positioned in the groove of the paper feed frame on the circumference and fastened on the paper feed frame, the tractor in the direction of the opening of the groove, A paper feed mechanism for a dot line printer, wherein a drive shaft, a guide shaft, and both shaft guides are assembled so that they can be removed from a paper feed frame. 2. A dot line printer having a hammerbank for printing on a printing paper in the form of a dot matrix and a platen for maintaining the printing power of the hammerbank, wherein the platen is a substantially rectangular parallelepiped, and both ends of the platen are The platen is held by a pair of side guides provided on the paper feed frame so that the platen can move in the printing force direction (the direction of the gap between the hammerbank and the platen). Then, a cam having a profile corresponding to the gap opening / closing amount between the hammerbank and the platen is brought into contact with a cam having a profile corresponding to the printing force holding surface of the platen, and the cam, the side guide, and one of the three in the beam direction of the platen. A spring is disposed so that a preload is applied in the direction, and both ends of the shaft are rotatably held on a paper feed frame, and the shaft is rotated. A paper feed mechanism for the dot line printer, wherein the distance between the hammerbank and the platen is adjusted by adjusting the distance between the hammerbank and the platen. 3. A hammerbank for printing on a printing paper in a dot matrix form, a platen for maintaining the printing power of the hammerbank, and a tractor for intermittently feeding the paper as printing is performed in dot rows. And a mechanical frame having a pair of side plates at both ends in the paper girder direction, in order to press the paper against the platen surface in order to maintain the stopping accuracy and settling of the paper during the printing operation of the hammerbank. Is fixed to the paper guide extending from the paper insertion slot, and the paper insertion slot side of the paper guide is rotatably held around the paper girder direction. Both ends are adjusted to a pair of side plates in an arc around the center of rotation of the paper guide paper insertion slot A paper feed mechanism for a dot line printer, wherein the paper feed mechanism is fastened as possible.