JPH0428775Y2 - - Google Patents

Description

[Detailed description of the invention] [Summary] This is a hammer mechanism for impact-type line printers that reduces hammer position accuracy due to play between the hammer and the hammer shaft, play between the hammer and the hammer block, and vibration of the hammer when driving the hammer. In order to
High printing quality is achieved by providing a guide not only at the hammer neck but also near the armature contacting part of the hammer.

[Industrial application field]

The present invention relates to a hammer mechanism for an impact type line printer.

For example, 17 hammers are mounted in the hammer assembly of an impact type line printer, and each hammer moves around a hammer shaft, and the hammer is usually pushed by the force of a recovery spring and separated from the printing surface. Due to the impact force of the armature attracted by the printing magnet, the hammer flies toward the paper and strikes the type on the type belt through the paper and ribbon to perform printing.

The hammer and type belt are constructed so that the type characters are in corresponding positions, but in reality, there are variations in component accuracy, so there is play in the part that guides the hammer, which reduces the accuracy of the hammer position and causes problems when driving the hammer. High-quality printing cannot be obtained due to hammer vibration. Therefore, a hammer mechanism that can provide high quality printing is required.

[Conventional technology]

A conventional type belt type line printer rotates a type belt 1 and an ink ribbon 2 formed in an endless shape, as shown in FIG. 2, for example, and a hammer 3 is provided opposite the type on the type belt 1.
By pressing the hammer 3, printing is performed on the paper 4 via the ink ribbon 2. In addition, 5 is type belt 1
6 is the type belt 1 during printing.
7 is a printing magnet, 8 is an ink ribbon accommodating section, 9 is a type belt drive motor, and 10 is a ribbon guide.

Figure 3 A to C are diagrams explaining the conventional hammer mechanism, where A is a front view, B is a view in the direction of arrow A (cross section), and C is a diagram showing the conventional hammer mechanism.
A' arrow view (hammer part).

In the figure, the hammer assembly is engaged with a hammer shaft 12 held by a hammer block 11, and has a structure in which, for example, 17 hammers 3 can be moved. In order to hold the hammer 3 from the back side of the hammer 3, a holder 13 is fixed to the hammer block 11 with a screw 14, and a recovery spring 15 is installed inside the holder 13.
Normally, the rear end B of the hammer 3 is pushed by the recovery spring 15, and the hammer 3 is kept away from the printing surface (type 16). FIG. 4 is a schematic diagram of the printing mechanism. When the printing magnet 7 is excited, it attracts the armature 17 and moves the hammer 3. Hammer 3 is armature 17
After the armature 17 stops, it flies in the direction of the paper and hits the type 16 on the type belt 1 via the paper 4 and ribbon 2, thereby performing printing. P is the rotation axis of the armature 17.

[Problem that the invention attempts to solve]

Conventionally, the hammer 3 is supported by a hammer shaft 12, guided by a groove 18 provided in the hammer block 11, and positioned.

However, when manufacturing parts, there are variations in the precision of the parts, and as a result, play occurs between the neck of the hammer 3 and the groove 18 of the hammer block 11, and between the hammer shaft 12 and the engagement hole 19 of the hammer block 11 (see Fig. 3). When the hammer 3 operates, a deflection 19 occurs in the hammer 3 corresponding to the backlash, and if the deflection is large, the striking surface D of the hammer 3 and the printing surface of the printing belt become misaligned, which may cause print defects. , or the striking surface D of the hammer 3 against the type surface of the type belt.
There was a problem in that the printout hit diagonally and unevenly, resulting in poor print quality.

[Means for solving problems]

Figures 1A and 1B are configuration diagrams of the hammer mechanism of the present invention.

This problem is solved by the hammer mechanism of the present invention, which is provided with a guide member 20 that not only guides the neck of the hammer 3 but also guides the vicinity of the armature contact portion on the opposite side to the hammer shaft 12.

[Effect]

That is, by guiding the vicinity of the armature contact portion of the hammer 3 with the guide member 20, both ends of the hammer shaft 12, that is, the neck portion of the hammer 3 and the armature contact portion are guided, and the neck portion of the hammer 3 engaged with the hammer shaft 12 is guided. Backlash is restricted. Therefore, the hammer runout is reduced, the striking surface D of the hammer 3 and the printing surface of the printing belt are prevented from facing each other, and high quality can be obtained.

〔Example〕

FIGS. 1A and 1B show an embodiment of the present invention, in which A is a side view and FIG. 1B is a front view showing the hammer and guide member in FIG. Note that the same parts are given the same reference numerals throughout the figures.

In the figure, the hammer assembly has a hammer shaft 1 held in a hammer block 11 as in the conventional case.
It has a structure in which, for example, 17 hammers 3 can be moved around the hammer 2. The hammer 3 is placed on a holder 13 that is fixed to the hammer block 11 from the back of the hammer 3.
The guide member 20 (in the example, the thickness of the hammer is 1.2 mm, the guide member is made of hard resin, and the width of the groove into which the hammer is inserted is 1.25 mm) that guides the armature contact portion B of is made by using the conventional screw 14. Fix it. Note that inside the holder 13, there is a recovery spring 15 (not shown, but there is a plunger that moves with the recovery spring) as in the conventional case, and the force of the recovery spring 15 causes the hammer 3 to move.
is pressed and is away from the printing surface (type 16).

Armature 1 is activated by excitation of the printing magnet.
7 is attracted and hits hammer 3. The hammer 3 flies due to the impact of the armature 17 and hits the type 16 on the type belt 1 through the paper and ribbon, thereby performing printing.
At this time, the neck of the hammer 3 is guided by the groove 18 of the hammer block 11, and the armature contact portion B on the opposite side of the hammer shaft 12 is guided by the guide member 20. The backlash between the hammer and the hammer 3 is limited, and the swing of the hammer 3 is reduced. This reduces the misalignment between the 3 sides of the hammer and the 16 types of type on the type belt 1.
This eliminates the occurrence of missing or hit prints, making it possible to obtain high print quality.

[Effect of idea]

As explained above, according to the present invention, not only the hammer neck is guided, but also the vicinity of the hammer armature contact area is guided, thereby preventing a drop in the positional accuracy of the hammer and reducing the swing of the hammer when the hammer is driven. , enabling high print quality.

[Brief explanation of the drawing]

Figure 1 is a diagram explaining an embodiment of the present invention, Figure 2 is a schematic diagram of a belt type printer, Figures 3A to 3C are diagrams explaining a conventional hammer mechanism, and Figure 4 is a schematic diagram of a printing mechanism. . In the figure, 1 is a type belt, 3 is a hammer, 1
1 is a hammer block, 12 is a hammer shaft, 13 is a holder, 14 is a screw, 15 is a recovery spring, 16 is a printing type, 17 is an armature, 18 is a groove, and 20 is a guide member.

Claims (1)

[Scope of utility model registration request] A hammer shaft 12 is supported by a hammer block 11, and a hammer 3 is rotatable while being engaged with the hammer shaft 12.
a holder 13 for holding the hammer 3, a mechanism for separating the hammer 3 from the type surface within the holder 13, and a guide for positioning the hammer 3 on the hammer block 11 near the hammer impact point of the hammer 3; A hammer mechanism characterized in that a guide member 20 for guiding the hammer 3 is provided near an armature contact portion of the hammer 3 on the opposite side of the hammer shaft 12 from the hammer impact point.