JPS5910918B2 - ribbon feeding mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ribbon feeding mechanism in a serial printer, etc., in particular, a ribbon cartridge is attached to a printing carriage, and the rotational force of a ribbon feeding motor mounted on the carriage is transmitted to a ribbon feeding roller in the ribbon cartridge. This relates to a ribbon feeding mechanism.

In general, with this type of ribbon feeding mechanism, if the ink ribbon is left slack, which occurs when the ribbon cartridge is replaced and installed in the carriage, etc., it may cause the paper to get caught on the ribbon when setting printing paper, or the ribbon may become loose during printing. Since the ribbon tends to deviate from a predetermined course on the print head, causing problems such as missing prints, it is necessary to remove slack in the ribbon as needed.

10 However, in conventional ribbon feeding mechanisms of this kind, the worm wheel is generally fixed to the torque shaft that is connected to the ribbon feeding roller and rotates it, so rotation operation from the driven side connected to the torque shaft is impossible. For manual feeding, it was necessary to install a knob for turning 15 on the worm shaft or to install a special dedicated switch in the motor drive circuit, but in the case of the former knob operation, a large amount of rotation was required depending on the worm gear ratio. Rotation must be applied, which takes time to operate, and in the latter case, the circuit configuration becomes more complicated.2
0 Each had their own drawbacks.

It is an object of the present invention to overcome such conventional difficulties and to realize a ribbon feeding mechanism that can easily feed the ribbon manually from the driven side, that is, from the ribbon cartridge side. While the motor is stopped, the ribbon can be automatically fed from the cartridge side.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings showing one embodiment thereof. 30 Printing In Figure 1, which is a view of the ribbon cartridge loading section of the carriage from diagonally below, the code 1 is
is a ribbon feeding motor screwed to the bracket 2a on the bottom surface of the cartridge mounting base 2, 3 is a worm fixed to its output shaft, 4 is a worm wheel that meshes with the worm 3, and 5 is a bush fixed to the base 2? (see FIG. 2), and the torque shaft 5 is attached to the ribbon in the ribbon cartridge C as shown in FIG. It is removably fitted to the feed roller 8 and rotates together with it by key connection.

Reference numeral 9 indicates a manual feed knob formed integrally with the roller 8. The torque shaft 5 and the worm wheel 4 are fitted and connected to each other via a bearing type one-way clutch 10. As the one-way clutch 10, various types of overrunning clutches known in the art may be used. For example, a commercially available 0WC type "one-way clutch" manufactured by Origin Electric Co., Ltd. can be used.One-way clutch 10
The inner and outer wheels are respectively fitted to the torque shaft 5 and the worm wheel 4, and are engaged when the motor is rotating to automatically feed the ribbon.When the motor is stopped, the torque shaft and the ribbon feed roller are connected to the worm wheel 4 to feed the ribbon. Allows rotation in relation to the feed direction.

That is, when the motor 1 is energized and rotates in the direction of the arrow when the printer starts printing, the worm wheel 4 is rotated by the worm 3 at a constant gear ratio (50:1 in this embodiment).
rotates in the direction of the arrow, the torque shaft 5 rotates together with the worm wheel 4 via the one-way clutch 10, and the ribbon feed roller 8 is rotated in the ribbon feed direction. Furthermore, while the motor 1 is stopped, if the knob 9 integrated with the roller 8 is turned by hand in the direction of the arrow in Figure 1 (the direction in which the ribbon is rolled up), the one-way clutch 10 is disengaged and the rotational force of the knob is transferred to the torque axis. The ribbon is transmitted to the clutch inner ring 10a fitted to the clutch 5, but is blocked there and is not transmitted to the clutch outer ring 10b, and the ribbon can be manually fed as desired by a knob operation. As is clear from the above description, according to the present invention, the ink ribbon can be transferred from the ribbon cartridge side with an extremely compact and simple structure that only incorporates a bearing type one-way clutch into a rotational force transmission system including a worm and a worm wheel. Manual feeding is now possible, making it possible to quickly and easily remove slack in the ribbon when loading a cartridge.

[Brief explanation of drawings]

FIG. 1 is a bottom perspective view of an embodiment of the present invention, and FIG. 2 is an enlarged vertical cross-sectional view around the torque axis thereof. 1: Ribbon feed motor, 2: Cartridge mounting base, 3: Worm, 4: Worm wheel, 5: Torque shaft, 8: Ribbon feed roller in cartridge C, 9:
Manual feed knob, 10: Bearing type one-way clutch.

Claims (1)

[Claims] 1. A ribbon feeding mechanism that transmits the rotational force of a ribbon feeding motor mounted on a print head carriage of a serial printer or the like to a ribbon feeding roller in a ribbon cartridge via a worm and a worm wheel, and is coupled to the ribbon feeding roller. The torque shaft and the worm wheel are fitted and connected to each other via a bearing type one-way clutch, and the ribbon is automatically fed by the rotation of the motor, while a knob integrated with the ribbon feed roller is used when the motor is stopped. A ribbon feeding mechanism for a serial printer, etc., characterized in that the ribbon can be fed manually.