JPS6234554B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ribbon change mechanism used in sequential serial printers.

In sequential serial printers, the printing mechanism and ribbon cartridge are typically mounted on a carriage that reciprocates along the platen. The ribbon cartridge is pivotally attached to the carriage and rotated about an axis parallel to the axis of the platen during ribbon changes. Conventionally, one electromagnet installed on the carriage has been used to rotate the ribbon cartridge, and the ribbon cartridge has been limited to two positions. In order to displace and rotate the ribbon cartridge between the three positions, it is necessary to use a large second electromagnet or to incorporate a complicated lever mechanism into the cartridge, which increases the weight of the cartridge and A large amount of power must be used to perform the reciprocating motion.

SUMMARY OF THE INVENTION An object of the present invention is to provide a lightweight and compact ribbon change mechanism that can displace a ribbon cartridge in three stages and does not significantly increase the weight even when incorporated into a cartridge. , two electromagnetic actuators are arranged on the cartridge, and the electromagnetic attraction forces of these electromagnetic actuators are approximately the same, and the two electromagnetic actuators are arranged on the cartridge.
The cartridge is rotated in stages, resulting in a total of three positions for the cartridge. That is, one electromagnetic actuator must first attract and rotate the ribbon cartridge before the other electromagnetic actuator can absorb the ribbon cartridge. In this way, it is not necessary to use an electromagnetic actuator with a large electromagnetic attraction force to rotate the ribbon cartridge to a position with a large displacement. All you have to do is place electromagnets with the same attraction at different levels. Note that the ribbon cartridge is resiliently held in place by a spring when both electromagnetic actuators are not energized.

According to one embodiment, the first electromagnetic actuator for initially pivotally displacing the ribbon cartridge from the aforementioned spring-loaded position is arranged on the spring-loaded side of the ribbon cartridge with respect to the pivot axis of the ribbon cartridge. and a lever made of a magnetic material that is engaged with an engaging piece protruding from the ribbon cartridge on the opposite side, and this lever is attracted to move the ribbon cartridge through the engaging piece against the loading force of the spring. It has an electromagnet that rotates it. A second electromagnetic actuating device for further rotationally displacing the ribbon cartridge includes a magnetic body fixed to the ribbon cartridge at a position spaced apart from the engaging piece, and a magnetic body fixed to the ribbon cartridge at a position spaced apart from the engaging piece; and another electromagnet arranged at a position such that this magnetic body approaches within the attractable range.

Hereinafter, the present invention will be explained by way of examples with reference to the accompanying drawings.

1 and 2, a ribbon cartridge 4 is pivotally mounted by a pivot shaft 3 on a carriage (shown only as a bearing portion 2 in FIG. 1) that reciprocates along a platen 1. As shown in FIGS. The ribbon cartridge 4 holds an ink ribbon 5 in a well-known manner, and the ink ribbon is located externally on the platen side of the ribbon cartridge 4. The carriage further supports a printing mechanism including a type 6 and a hammer 7, where the ink ribbon 5 is located between the platen 1 and the type 6, and the hammer 7 strikes the type 6 to form a print sheet 8 (a second (shown only in figure)
It is now possible to print on the

The ink ribbon 5 is divided into two layers, upper and lower.
In the position of the ribbon cartridge 4 shown in the figure, the ink ribbon 5 is not located directly between the type 6 and the platen 1, and this first position is usually called the visible position and does not display printed characters. It is in a position where it can be seen visually. FIG. 3 shows a second position where the upper layer of the ink ribbon 5 is located between the platen 1 and the type 6;
That is, the ribbon cartridge 4 is shown in the upper layer selection position, and FIG. 4 shows the ribbon cartridge 4 in the third position, that is, the lower layer selection position.

The ribbon change mechanism that allows the ribbon cartridge 4 to assume the various positions described above has a base 10 attached to the underside of the ribbon cartridge 4. The base 10 has an extension 11 that protrudes from the pivot shaft 3 toward the platen, and a tension spring 1 is connected between the extension 11 and a carriage portion (not shown).
2 is attached to resiliently load the base 10 and thus the ribbon cartridge 4 counterclockwise toward the visible position. In the visible position,
The base extension 11 engages the stopper 13 and is prevented from further movement.

The base 10 has a downward extension 14 at an end opposite to the extension 11, and the tip of the downward extension 14 is bent inward to form an engagement piece 15. A lever 16 is provided to engage with the inner surface of the engaging piece 15, and the opposite end of the lever 16 is rotatably mounted concentrically with the pivot shaft 3. Considering this state from the lever side, the lever 16 is engaged with the engagement piece 15 on the side opposite to the side on which the ribbon cartridge 4 is loaded by the spring.

The lever 16 is made of a magnetic material, and a first electromagnet 18 is disposed adjacent to the portion of the lever that engages with the engagement piece. This first electromagnet 18
The distance between the lever 16 and the lever 16 is within the suction possible range.
Therefore, when the first electromagnet 18 is excited,
The lever 16 is immediately attracted and rotated counterclockwise against the force of the spring 12, thereby rotating the base 10 and therefore the ribbon cartridge 4 counterclockwise via the engagement piece 15. The ribbon upper layer selection position shown in FIG. 3 is taken.

spaced apart from and transverse to the first electromagnet 18;
That is, in the direction of the axis 1A of the platen 1 and the first
A second electromagnet 20 is disposed at a higher position than the electromagnet 18, that is, at a position closer to the bottom surface of the ribbon cartridge 4. A magnetic body 21 is fixed to a base portion corresponding to the second electromagnet 20.
The distance between this magnetic body 21 and the second electromagnet 20 is out of the attractable range in the visible position of the ribbon cartridge 4 shown in FIG. It is not possible to attract the magnetic body 21 against the force. That is, in this position, the ribbon cartridge 4 cannot be rotated by the second electromagnet. However, as shown in FIG. 3, when the ribbon cartridge 4 is in the upper layer selection position, the magnetic body 21 approaches the second electromagnet 20 and enters the attractable range. Therefore, when the second electromagnet 20 is excited at this position, the ribbon cartridge 4 is further rotated counterclockwise to take the ribbon lower layer selection position shown in FIG. At this time, the engagement piece 15 of the base 10 separates from the lever 16. Therefore, there is no hindrance to the rotation of the ribbon cartridge 4 to the position shown in FIG.

When it is desired to maintain the ribbon cartridge 4 at each ribbon layer selection position, a holding current may be applied to each electromagnet. If this condition occurs,
It is clear that the other electromagnet may be demagnetized. Furthermore, in order to displace the ribbon cartridge 4 from the position shown in FIG. 4 to the position shown in FIG. It is clear that the tray 4 is displaced.

According to the present invention, since the electromagnet is installed very close to the object to be attracted, it is possible to use an electromagnet with a relatively small attraction force, and even if the amount of displacement is large, it is only necessary to use the same attraction force. , it is possible to obtain a small and lightweight ribbon change mechanism capable of displacing the ribbon cartridge to the three positions mentioned above.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view of a ribbon cartridge equipped with a ribbon change mechanism according to the present invention, and FIG.
Figure 3 is a side view of the ribbon cartridge shown in Figure 1; Figure 3 is a view similar to Figure 2 showing the ribbon cartridge in another position; Figure 4 shows the ribbon cartridge in yet another position. FIG. 2 is a diagram similar to FIG. 2; 1...Platen, 3...Pivot axis, 4...Ribbon cartridge, 5...Ink ribbon, 6...
Type, 7... Hammer, 10... Base, 12...
Spring, 16... lever, 18, 20... electromagnet,
21...Magnetic material.

Claims (1)

[Claims] 1. A ribbon cartridge is provided to be rotatable in a first rotational direction and a second rotational direction opposite to the first rotational direction around a rotational axis located approximately at the center of the ribbon cartridge mounted parallel to the platen. a cartridge base; a spring means and a stopper means for biasing the cartridge base in the first rotational direction and positioning the cartridge base in a first position; and a side of the cartridge base spaced apart from the platen with respect to the rotational axis. an engaging piece that is rotatably provided on the rotating shaft and that extends in a direction away from the platen; A lever whose tip engages the engaging portion when the cartridge base is in the first position, and a suction surface of the lever when the cartridge base is in the first position. a first electromagnetic actuating means disposed in the second direction of rotation with a second distance shorter than the first distance, the first electromagnetic actuating means positioning the cartridge base in a second position; The cartridge is disposed in the second rotational direction and has a third distance between it and the suction surface of the cartridge base when the cartridge is in the position. and second electromagnetic actuating means for positioning the trigger base in a third position.