JPH082079A - Ribbon feed mechanism - Google Patents

Abstract

PURPOSE:To normally operate a motor by always making the timing of the load of a ribbon applied to the motor constant even when a carrier is moved in both of left and right directions after stop. CONSTITUTION:The ribbon feed mechanism is equipped with the pinion gear 3 rotated by a rack 1 or a wire accompanied by the movement of a carrier 2 and the planetary gear 4 attached to a planetary gear arm 5 to be rotated along with the pinion gear 3 rotating a feed gear 10 only in one direction without being affected by the moving direction of the carrier 2. Further, two idle gears 6 arranged on the same shaft to be connected through a leaf spring so that one of them is meshed with the planetary gear 4 to be rotationally driven and the other one of them rotationally drives the ribbon feed gear 10 are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ribbon feed mechanism, and more particularly to a ribbon feed mechanism for a serial printer.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing an example of a conventional ribbon feed mechanism. Referring to FIG. 4, in this conventional ribbon feed mechanism, the force of the carrier 2 moving left and right is converted into rotational power by a pinion gear 3 meshed with a fixed rack 1, and the power is transmitted to each gear. At this time, the ribbon feed gear 10 is rotated in a fixed direction by the planetary arm 5 arranged coaxially with the pinion gear 3 and the planetary gear 4 supported by the planetary arm 5, regardless of the moving direction of the carrier 2.

[0003]

In this conventional ribbon feed mechanism, the carrier 2 moves from left to right, then from right to left, and from left to right. In this case, the gear meshing with the planetary gear 4 is switched to the idle gear 6 or the second idle gear 11 every time, so that the ribbon load is increased by the carrier 2.
It takes a certain time for the motor to move. When the carrier 2 moves in the same direction, that is, after moving from left to right and then from left to right, the planetary gear 4 should be switched while meshing with the gear that was meshed when it was first moved. Since the next movement is performed without doing so, the time until the load of the ribbon is applied to the motor is zero. Therefore, while there are two types of load timing applied to the motor, there is only one type of motor drive sequence, and the motor drive sequence and load timing cannot always be matched, and the motor cannot operate normally and is abnormal. It may stop.

[0004]

In the ribbon feed mechanism of the present invention, a pinion gear that is rotated by a rack or a wire due to movement of a carrier and a ribbon feed gear that drives a ribbon are integrated without being affected by the moving direction of the carrier. The planetary gear, which is rotated only in the direction, rotates together with the pinion gear and is attached to the planetary arm, and is coaxially arranged and connected via a leaf spring. And two idle gears that rotate and drive the ribbon feed gear.

[0005]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. FIG.
Referring to FIG. 3, the ribbon feed mechanism of this embodiment is configured so that the pinion gear 3 that rotates by the rack 1 or the wire when the carrier 2 moves and the ribbon feed gear 10 that drives the ribbon are not affected by the moving direction of the carrier 2. The planetary gear 4 which is rotated only in the direction, rotates together with the pinion gear 3 and is attached to the planetary arm 5, is coaxially arranged and connected via a leaf spring 8, and one of them is rotationally driven by meshing with the planetary gear 4. The other is composed of two idle gears 6 that rotate and drive the ribbon feed gear 10.

2 and 3 show a second idle gear 7
FIG. 4 is a sectional view of a leaf spring 8 and a tension idle gear 9. The operation of this embodiment will be described with reference to FIGS. 2 and 3 together with FIG. The pinion gear 3 in the carrier 2 that meshes with the rack 1 rotates as the carrier 2 moves left and right. At this time, the rotation direction of the pinion gear 3 changes according to the moving direction of the carrier 2. On the other hand, since the ribbon can be wound only in one direction, the rotation of the pinion gear 3 cannot be directly transmitted to the ribbon. Therefore, the rotation direction of the idle gear 6 and the second idle gear 7 is limited to one direction by the planet gear 4 meshed with the pinion gear 3 and the planet arm 5 that supports the planet gear 4 and works in accordance with the rotation direction of the pinion gear 3. Let Since the idle gear 6 meshes only with the planet gear 4 and the second idle gear 7, the second idle gear 7 must be interposed in order to rotate the ribbon feed gear 10 directly connected to the ribbon. Therefore, the tension idle gear 9 is arranged on the same axis as the second idle gear 7 and connected by the leaf spring 8. Due to the power of the second idle gear 7 that rotates due to the movement of the carrier 2, the leaf spring 8 bends until it exceeds the load for winding the ribbon. After that, when the load of winding the ribbon is exceeded, the leaf spring 8 does not bend further, and the power of the second idle gear 7 is transmitted to the tension idle gear 9.
The ribbon feed gear 10 meshing with the tension idle gear 9 rotates, and the ribbon is wound.

Next, when the carrier 2 stops, the leaf spring 8
Releases the deformation energy of the deflection accumulated during the operation of the carrier 2. At this time, since the deformation energy of the leaf spring 8 is smaller than the load of winding the ribbon, the leaf spring 8 is transmitted not to the ribbon feed gear 10 but to the second idle gear 7 for rotation. The second idle gear 7 rotated by the leaf spring 8 is engaged with the planetary gear 4 when the planetary gear 4 is engaged.
When the planet gear 4 meshes with the idle gear 6, the planet gear 4 tries to rotate via the idle gear 6. However, the planet gears 4 are
It cannot rotate because it is also meshed with the pinion gear 3 that meshes with the second pinion gear 3 and because it is in a state where it can freely move by the planetary arm 5, a tooth skipping phenomenon occurs with the second idle gear 7 or the idle gear 6, and the second idle gear It moves to a position where neither gear 7 nor idle gear 6 meshes and stops. As a result, the planetary gear 4 always stops at a specific position when the carrier 2 stops,
Next, when the carrier 2 starts moving, the load timing for winding the ribbon can be made constant.

[0008]

As described above, according to the present invention,
Since the planetary gear is always stopped at a specific position when the carrier stops, the motor is driven by keeping the ribbon load timing on the motor that moves the carrier constant regardless of the carrier's operation. Match the sequence with the ribbon load timing to always operate the motor normally.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a second idle gear, a leaf spring, and a tension idle gear of this embodiment.

FIG. 3 is a sectional view of a second idle gear, a leaf spring, and a tension idle gear of this embodiment.

FIG. 4 is a configuration diagram showing a conventional example.

[Explanation of symbols]

 1 rack 2 carrier 3 pinion gear 4 planetary gear 5 planetary arm 6 idle gear 7 second idle gear 8 leaf spring 9 tension idle gear 10 ribbon feed gear 11 second idle gear

Claims (1)

[Claims] 1. A pinion gear that is rotated by a rack or a wire when a carrier is moved and a ribbon feed gear that drives a ribbon are rotated in only one direction without being affected by the moving direction of the carrier, and are rotated together with the pinion gear. Two idle gears arranged coaxially with a planetary gear attached to a planetary arm and connected via a leaf spring, one of which is rotationally driven by meshing with the planetary gear and the other is rotationally driven of the ribbon feed gear. A ribbon feed mechanism comprising: