JPS62253460A - Hammer bank driver for dot printer - Google Patents

Abstract

PURPOSE:To prevent a hammer bank from being deformed and contrive higher printing quality and a higher printing speed, by locating the point of force of a shuttle mechanism for reciprocating the hammer bank, substantially on the line of center of gravity of the hammer bank which line is parallel to a printing line. CONSTITUTION:A joint plate 40 is fixed astride two shafts 33, and is fixed to a hammer bank 10 through bolts 43 located substantially on the line of center of gravity of the hammer bank 10. As a result, the stiffness of the joint part of the hammer bank 10 and a shuttle mechanism 30 is enhanced, deformation of the joint part is reduced, and deformation of the hammer bank 10 is also reduced. The point of force for accelerating and decelerating the hammer bank 10 by the shuttle mechanism 30 is located substantially on the line of center of gravity of the hammer bank 10, so that bending moments are scarcely generated at the time of acceleration or deceleration of the hammer bank 10, and the hammer bank 10 is not deformed in such situations. Accordingly, high printing quality and a higher printing speed can be contrived.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention reciprocates along the printing line a hammer bank holding a plurality of dot printing hammers spaced apart along the printing line. This relates to the hammer bank drive device of a dot printer that prints during this reciprocating process. .

[Background of the invention]

In such a printer, in order to ensure a predetermined print quality, that is, the positional accuracy of dot printing, and to ensure dot printing, the load that acts on the hammer bank as it accelerates and decelerates during reciprocating movement of the hammer bank.

It is essential to prevent deformation of the hammer bank caused by bending moments etc. for the following reasons.

If the hammer bank deforms and the distance between the printing hammer and the platen (hereinafter referred to as the hammer gap) changes, the printing hammer will no longer be able to maintain the specified printing ability. That is, an increase in the hammer gap significantly reduces the repeatability of the printing hammer, and even if the hammer gap becomes wider by about 0.05, the repeatability decreases and a predetermined printing speed cannot be maintained. On the other hand, the hammer gap is 0.05
If it becomes narrower, there will be problems such as the paper being smeared by the ink ribbon, the ink ribbon not running stably, and the position of the printing hammer changing, causing misalignment of dot printing.

When the printing speed is increased, the acceleration and deceleration of the hammer bank during reciprocating movement increases, and the load acting on the hammer bank increases, so the bending moment increases. In order to keep the deformation of the hammer bank due to bending moments below the allowable value, it is possible to increase the bending rigidity of the hammer bank. However, simply increasing the bending rigidity increases the weight of the hammer bank, making high-speed printing difficult, etc. There is a problem.

[Purpose of the invention]

An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, and to prevent deformation of the hammer bank due to acceleration/deceleration with a simple configuration, thereby making it possible to improve printing quality and printing speed. .

[Summary of the invention]

The present invention focuses on the fact that the bending moment can be reduced by aligning the point of force from the shuttle mechanism that reciprocates the hammer bank approximately on the center of gravity line parallel to the printing line of the hammer bank, and makes it possible to secure the position of the point of force. The feature is that the method of connecting the hammer bank and shuttle mechanism has been devised.

[Embodiments of the invention]

Hereinafter, embodiment drawings will be explained with reference to the present invention.

The left end of the hammer bank IO holding a plurality of dot printing hammers 11 provided at a predetermined pitch along the printing line is
It is slidably supported by a sliding bearing 21 fixed to a frame (not shown) via a mount block 12 and a shaft 13. Hammer bank 10 and shaft 1
3 are fixed to the mount block 12 by bolts 41, respectively. Further, the right end of the hammer bank IO is connected to the shuttle mechanism 30 via a joystick plate 40. The shuttle mechanism 30 includes: a cam 36 driven by a motor (not shown); a pair of cam followers 31 that contact the cam 36; It is composed of a shift plate 32 having the cam follower 31 mounted on its upper surface, two shafts 33 to which the shift plate 32 is fixed with screws 34, and the like. The shaft 33 is slidably supported by a sliding bearing 22 mounted on the frame, and its left end is attached to the joint plate 40 via a bolt 42.

The joint plate 40 is fixed to the hammer bank 10 via bolts 43. The bolt 43 is positioned on the center of gravity line parallel to the printed line of the hammer bank IO. In addition, 50 is an ink ribbon, 51 is a ribbon guide, 52 is a cassette for storing the ink ribbon 5o,
53 is a drive roller that drives the ink ribbon 50, 6
0 is paper, and 70 is a platen.

+"+ When the cam 36 rotates, the cam follower 31, shift plate 32, and shaft 33 reciprocate in the left-right direction in the figure, that is, along the printing line. As a result, the hammer bank 10 also reciprocates, and in the process of this reciprocating movement, Printing is performed by driving the dot printing hammer 11.

The above-mentioned oval or joint plate 40 is fixed across the two shafts 33 and fixed to the hammer bank 10 via the bolt 43 located approximately on the center of gravity of the hammer bank 10. 10 and the shuttle mechanism 30, and the deformation of the joint becomes small.
The deformation of 0 also becomes smaller.

In addition, since the point of force for accelerating and decelerating the hammer bank 10 by the shuttle mechanism 30 almost coincides with the center of gravity of the hammer bank 10, almost no bending moment is generated due to acceleration and deceleration of the hammer bank 10, and the hammer bank 10 It will no longer deform.

When the joint plate 40 is configured to be fixed to only one shaft 33 as shown in FIG. 2, the rigidity of this connecting portion becomes small and the connecting portion becomes easily deformed, causing deformation of the hammer bank 10. Hammer bank 1 as it gets bigger
The distance between the center of gravity of the rehammer bank 10 and the center of the shaft 33 is the length of the arm, and the bending moment with the inertial force accompanying the acceleration and deceleration of the rehammer bank 10 as a load is determined by the dashed line and the two points g!
Bending moments in the directions indicated by single lines act on the hammer bank 10 alternately, so that the hammer bank IO is deformed to curve as shown by the dashed line and the dashed double dot line.

〔Effect of the invention〕

As explained above, according to the present invention, the force point from the shuttle mechanism that accelerates and decelerates the hammerbank is made to almost coincide with the center of gravity of the hammerbank, so that the bending moment accompanying acceleration and deceleration of the hammerbank is eliminated. This makes it possible to prevent the hammer bank from deforming, ensuring printing quality and increasing printing speed.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the device of the present invention. 2 is a plan view for explaining the deformation of the hammer bank. In FIG. 0, 10 is a hammer bank, 11 is a dot printing hammer, 30 is a shuttle mechanism, 33 is a shaft, 4
0 is a joint plate, and 41 to 43 are bolts.

Claims (1)

[Claims] In a dot printer in which a hammer bank holding a plurality of dot printing hammers at predetermined intervals along a printing line is reciprocally moved along the printing line by a shuttle mechanism, and printing is performed in the process of this reciprocating movement, the shuttle mechanism A dot printer characterized in that at least two movable shafts and a hammer bank are connected by a joint plate, and the plate is fixed to the hammer bank near the center of gravity parallel to the printing line of the hammer bank. hammer bank drive device.