JPS6315155B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ink ribbon feeding mechanism used in an impact printer, and more particularly to a mechanism for feeding an ink ribbon by reciprocating movement of a wire or belt.

Conventionally, in this type of ink ribbon feeding mechanism, the wire or belt is driven using power for spacing the printing head, and the wire or belt moves back and forth in the same way as the printing head moves. For this reason, the ink ribbon is fed only while the wire or belt is moving in one direction, and not fed while the wire or belt is moving in the opposite direction, so that the ink ribbon continues to be fed in the same direction. However, with recent bidirectional printing printers, printing continues even when the ink ribbon is not being fed, so
There were drawbacks such as the ink ribbon being pulled out by printing elements such as type letters flying onto the printing surface, causing sagging.

The present invention eliminates the above-mentioned drawbacks by ensuring that the ink ribbon continues to be fed in the same direction even if the direction of movement of the wire or belt is reversed.

The present invention will be described in detail below with reference to the illustrated embodiments.

FIG. 1 is a plan view showing one embodiment of the present invention, and FIG.
The figure is a sectional view taken along the line A-A' in FIG. 1 in the direction of the arrow, and FIG. 3 is a plan view showing another state of FIG. 1.

In FIGS. 1 to 3, 1a and 1b are driven gears that are coaxially supported with the winding shafts of a pair of left and right ribbon spools (not shown), 2 is a wire that reciprocates in both left and right directions, and 3 is a wire attached to the outer periphery. a drum around which the wire 2 is wound; 4 a first drive gear coaxially supported with the drum 3; 5 a second drive gear meshing with the first drive gear 4; 6 a pivot 7; The detent lever is rotatably supported around the
Reference numeral 8 denotes a ribbon feed reversing bar that is moved laterally by an eyelet at the end of the ribbon and switches from one position to the other. Reference numeral 9 extends between a pin on the ribbon feed reversing bar 8 and the rear end of the detent lever 6. The detent springs 10a and 10b are stoppers 1 for regulating the rotational position of the detent lever 6.
1 is rotatable about a pivot 12 supported by a detent lever 6 on a straight line connecting the central axis 4a of the first driving gear 4 and the central axis 5a of the second driving gear 5, and has the A rotary lever that pivotally supports the first drive gear 4 and the second drive gear 5 at the other end; 13 is an ink ribbon wound from one side of a ribbon spool (not shown) to the other; 14 is a detent lever 6, and the central shaft 4a of the first drive gear 4 is a long hole into which the central shaft 4a is loosely fitted.

In the ink ribbon mechanism configured as described above, when the wire 2 moves to the right as shown in FIG. , the central shaft 4a moves rightward into the elongated hole 14 of the detent lever 6. This movement causes the first drum coaxial with the drum 3 to
The driving gear 4 escapes to a position where it does not mesh with the driven gear 1a. As the first drive gear 4 moves to the right, the rotary lever 11, which supports the central shaft 4a of the gear at one end, rotates counterclockwise about the pivot 12, causing the second drive gear 5 to move to the left. to mesh with the driven gear 1a. As a result, the movement of the wire 2 is transmitted via the second drive gear 5 and the driven gear 1a is rotated counterclockwise.

Next, when the wire 2 moves to the left in the opposite direction to the above, the drum 3 rotates clockwise and is pulled to the left, and the central shaft 4a moves inside the elongated hole 14 of the detent lever 6 as shown in FIG. It moves to the left, and the first drive gear 4 meshes with the driven gear 1a. On the other hand, the rotating lever 11 is rotated by the pivot 12 due to the movement of the central shaft 4a.
The second drive gear 5 is rotated clockwise around the center to release the second drive gear 5 to a position where it does not mesh with the driven gear 1a. As a result, the movement of the wire 2 is transmitted through the first drive gear 4, and the driven gear 1a moves in the same counterclockwise direction as when the wire 2 moves to the right due to the clockwise rotation of the first drive gear 4. rotated to

In this way, the driven gear 1a always rotates counterclockwise regardless of the direction of movement of the wire 2, so that the ink ribbon 1 is continuously fed in the same direction even if the drive source for the wire 2 repeats forward and reverse rotations.

When the end of the ribbon is unwound, the ribbon feed reversing bar 8 is shifted to the right, and the detent lever 6 is moved to the pivot 7 by the detent spring 9.
It rotates clockwise around , and comes to rest when its rear end hits the stopper 10a. Therefore, the first drive gear 4 and the second drive gear 5 move toward the driven gear 1b. Now when wire 2 moves to the right, the first
The driving gear 4 meshes with the driven gear 1b, and the wire 2
moves to the left, the second driving gear 5 shifts to the driven gear 1
b, and the driven gear 5 continues to rotate clockwise regardless of the direction of movement of the wire 2.

As described above, according to the ink ribbon feeding mechanism of the present invention, even if the direction of movement of the wire that reciprocates to provide power for feeding the ink ribbon is reversed, the ink ribbon continues to be fed in the same direction, and both Even when used in a printer for direct printing, the ink ribbon does not sag.

Note that the present invention is not limited to the above embodiments, and a belt may be used instead of a wire,
Further, the present invention is applicable not only to a ribbon spool type ink ribbon device but also to an endless ink ribbon feeding device that does not perform reversal of ribbon feeding.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing one embodiment of the present invention, and FIG.
The figure is a sectional view taken along the line A-A' in FIG. 1 in the direction of the arrow, and FIG. 3 is a plan view showing another state of FIG. 1. 1a, 1b...driven gear, 2...wire, 3...
...Drum, 4...First drive gear, 5...Second drive gear, 6...Detent lever, 8...Ribbon feed reversal bar, 9...Detent spring, 11
...Rotary lever.

Claims (1)

[Scope of Claims] 1. In an ink ribbon feeding mechanism provided in a frame of a printer for feeding an ink ribbon to a printing surface by reciprocating movement of a wire or belt linked to the spacing of a printing head, an end-shaped a pair of left and right driven gears for winding up the ink ribbon; a first drive gear that rotates in forward and reverse directions due to the reciprocating motion of the wire or belt; a second drive gear that meshes with the first drive gear; A rotary lever that has first and second drive gears at both ends and rotates forward and backward in response to reciprocating switching of the direction of movement of the wire or belt; a support member provided on the frame so as to be swingable between the pair of driven gears; a ribbon feed reversal bar that moves based on detection of the end of the ink ribbon; and a detent spring biased so that the support member rotates forward and backward in response to movement of the reversing bar, and one of the first and second drive gears meshes with one of the driven gears. winding the ink ribbon in the same direction by means of a configuration in which the engaging drive gear is switched with the forward and reverse rotation of the rotary lever according to the reciprocating switching of the wire or belt, and the end of the ink ribbon is detected. An ink ribbon feeding mechanism characterized in that the ink ribbon is wound in the opposite direction by a structure in which a driving gear at the tip of the support member meshes with the other driven gear by the accompanying swinging of the support member.