JPS58179683A - Ribbon driver for typewriter - Google Patents

Abstract

PURPOSE:To obtain a ribbon driver for typewriter, having a function to select the actions of a brake device according to the kinds or ink ribbons, by providing two kinds of brake devices between a spool attached with an ink ribbon cassette and a driving part for the brake devices. CONSTITUTION:When a carbon ribbon cassette 6 is attached to the spool shafts 4 and 5 of a ribbon driver, a collar 17 provided to the supporting shaft 3 on the supply side is fitted into the supporting cylinder 20 of the cassette 6 in non-contact state. By this, the force of a compression spring 18 is kept at a given value and a weaker brake force than the first brake device on the winding side is given to the spool shaft 5 by the second brake device 19. On the other hand, when a cloth ribbon cassette 7 is set, the collar 17 of the second brake device 19 comes into contact with the downside of an operating knob 21 provided to one spool 9b of the cloth ribbon cassette 7 and is moved downwards, and a compression spring 18 strongly presses the spool shaft 5 downwards. Thus, the brake force to be given to the spool shaft 5 by the second brake device 19 becomes equal to that of the first brake device on other spool shaft 4 side because it is strengthened as compared with the case where the carbon ribbon cassette 6 is set.

Description

TECHNICAL FIELD This invention relates to a typewriter ribbon drive.

Conventional ribbon force cent type typewriters generally have a carbon ribbon cassette and a cloth ribbon cassette driven by a common drive device. However, when printing with a carbon ribbon cassette installed, if the braking force acting on the supply spool is too strong to maintain a constant tension on the ribbon exposed outside the cassette,
When the ribbon part located at the printing position is printed on printing paper as the printing element moves forward, the tension applied to the carbon ribbon prevents the carbon ribbon from being pulled out sufficiently from the supply spool, causing the carbon ribbon to lose its elasticity. It is stretched once against resistance.

Therefore, when the printing element moves back, the carbon ribbon is released from the pinched state between the printing element and the printing paper, and the stretched carbon ribbon moves to the supply spool side while being in contact with the printing paper due to its elastic restoring force. There is an inconvenience that the print is smeared due to being rewound. On the other hand, when printing with a cloth ribbon cassette installed, there is little risk that the cloth ribbon will be stretched during printing by the printing element, but if the braking force acting on the supply spool is weak, the The spool moves loose and the cloth ribbon becomes loose, and the loosened cloth ribbon separates from the vibrator (3), causing a ribbon jam.

However, the ribbon drive device in conventional typewriters is configured to feed each ribbon under the same conditions regardless of the differences in the properties of carbon ribbons or cloth ribbons, so the above-mentioned problems occur. Satisfying both conditions was an extremely difficult national challenge. It is also conceivable to provide each ribbon cassette with a braking mechanism to appropriately adjust the rotation of each spool, but such a configuration would increase the cost of each ribbon cassette that is replaced. be.

Purpose This invention was made to solve the above-mentioned conventional inconveniences, and its purpose is to prevent print smudges and obtain clear prints when using a carbon ribbon cassette, and to provide a cloth ribbon cassette with a cloth ribbon cassette. An object of the present invention is to provide a novel (4) typewriter ribbon and drive device capable of eliminating slack in a cloth ribbon and avoiding ribbon jam when used in a typewriter.

EXAMPLE Hereinafter, an example embodying the present invention will be described based on the drawings. As shown in Figure 1, the typewriter frame (
(not shown) A pair of support pieces 1a are attached to the substrate 1 to be attached.
are formed, and support shafts 2 and 3 are fixed to protrude from each support piece 1a, respectively.

Both support shafts 2 and 3 have spool shafts 4.5 as driving members.
are rotatably supported, and have cylindrical spool fitting portions 4a, 5a provided at their upper portions, and disc-shaped ratchet wheels 4b, 5b provided at their lower portions. and,
On both spool shafts 4 and 5, a carbon ribbon cassette 6 as shown in FIG. 2 or a cloth ribbon cassette 7 as shown in FIG. A pair of spools lla and 8b for carbon ribbons or spools 9a and 9 for cloth ribbons
b is fitted into the fitting parts 4a and 5a of both spool shafts 4 and 5, respectively, and both spools 8a, 9b or 9
A part of the carbon ribbon 10 or cloth ribbon 11 provided between a and 9b is attached to each ribbon cassette 6. It is exposed to the outside from inside the flap and guided to a printing position on the front surface of the platen of the typewriter by a vibrator (not shown) or the like.

As shown on the right side of FIG. 2, a washer 13 is provided on the top of the front support shaft 2 corresponding to the take-up spool 8a of the carbon ribbon cassette 6 with a retaining ring 12. There is a leaf spring 1 between the upper surface of the fitting part 4a and the upper surface of the fitting part 4a.
4 is interposed.

And these retaining rings 12. Washer 13. A first braking device 15 in this embodiment is constituted by a leaf spring 14 and the like, and the action of the leaf spring 14 constantly presses the spool shaft 4 downward to brake its rotation.

On the other hand, as shown on the left side of FIG. 2, a collar 17 is rotatably and downwardly supported by a retaining ring 16 at the top of the support shaft 3 corresponding to the supply spool 81) of the carphone ribbon cassette 6. A compression spring 18 is interposed between the lower surface of the collar 17 and the upper surface of the fitting portion 5B of the spool shaft 5. And these retaining rings 16. Color 17. A second braking device 19 for braking the rotation of the spool shaft 5 is constituted by the compression spring 18 and the like, and its braking force is equal to the braking force of the first braking device 15 when the ribbon cassette 6.7 is not attached. It is set to be weaker than the power.

On the lower surface of the cover plate 6a of the carphone ribbon cassette 6,
A supporting cylindrical portion 20 that fits into the hollow upper end of the supply spool 8b is provided protrudingly, and when the carbon ribbon cassette 6 is installed, the collar 17 of the second drive device 19 is not inserted into the supporting cylindrical portion 20. They are fitted in contact. Therefore, in this case, the spring force of the compression spring 18 is not changed and the second brake 1 device 19 is replaced by the first brake 1 device 1.
A weaker braking force is applied to the spool shaft 5Vc than that of the spool shaft 5Vc, thereby braking its rotation.

As shown in FIG. 3, there is an operation knob 21 in the center of the upper surface of the left spool 9b of the cloth ribbon cassette 7.
is protruded, and when the cloth ribbon cassette 7 is installed,
The lower surface of this operating knob 21 comes into contact with the upper surface of the collar 17 of the second braking device 19, and moves the collar 17 downward against the spring force of the compression spring 18. Therefore, in this case, due to the spring force of the compression spring 1B in the compressed state, the second braking device 19 applies a braking force equivalent to that of the first braking device 15 to the spool shaft 5, thereby braking its rotation. It's like doing that.

As shown in FIG. 1, a drive lever 22 is rotatably supported at the lower end of the support shaft 2 at the lower end of the support shaft 2 on the lower side of the right support piece 1a of the board 1, and is engaged with one end of the drive lever 22. pin 23
is provided protrudingly, and a connecting rod 24 is hooked to the other end for linking with a typewriter's printing mechanism or the like. At the bottom of the left support shaft 3 is an interlocking lever 25.
is rotatably supported at its base end, and an elongated hole 26 into which the engagement pin 23 of the drive lever 22 is inserted is formed at its tip. Both levers 22 and 25 are rotated back and forth via the connecting rod 24 in conjunction with the operation of the printing mechanism and the like.

A claw member 28 is rotatably supported on the upper surface of the drive lever 22 and the interlocking lever 25 by a support shaft 27VC, and a model wheel 4b of the spool shafts 4, 5 is attached to one end of the claw member 28.
, 5blC engageable pawl portions 28a are formed, and each pawl member 28 is provided with a tension spring 29 to engage the corresponding mold wheel 4b, 5b.
is biased in the direction of engagement. When the cloth ribbon cassette T is attached and used, a switching mechanism (not shown) for changing the winding direction of the ribbon is operated by the claw member 2
Either one of them is selectively engaged with the corresponding model wheel 411, 511. Therefore, when the claw members 28 are driven with the reciprocating rotation of the drive lever 22 and the interlocking lever 25, one of the claw members 28
One of the pattern wheels 4b or 5]) engaged with
a or 9bVc are wound up sequentially.

Further, as shown in FIG. 3, a detection member 30 for detecting the presence or absence of the cloth ribbon 11 on each spool 9a, 9b is rotatable in the groove portions 4c, 5c formed in each spool shaft 4.5. They are each biased clockwise in the figure by a spring 31 hooked to the lower end engagement protrusion 30a. Furthermore, a connecting member 32 having an engaging claw 32a that can be engaged with and disengaged from the engaging protrusion 30a of the detection member 30 is rotatably inserted into the supporting shafts 2 and 3 at the lower part of both the spool shafts 4 and 5. .

As shown in FIG. 3, when the cloth ribbon cassette 7 is installed, the cloth ribbon 1 is attached to the right spool 9a.
1 winding is completed and it is time to change the winding direction of the cloth ribbon 11, the detection member 30 of the left spool shaft 5 is rotated, and the engaging protrusion 30a is moved to the connecting member 3.
The second engaging claw 32aVc engages. Therefore, the connecting member 32 is rotated integrally with the spool shaft 5, and the above-described switching mechanism is operated to switch the feeding direction of the cloth ribbon 11.

As shown in FIG. 2, when the carbon ribbon cassette 6 is installed and in use, the spool 8a fitted on the right spool shaft 4 is always on the winding side, and the spool 8a fitted on the left spool shaft 5 is always on the winding side. 8; ] is the supply side, and the carbon ribbon 10 is wound in one direction.

Finally, the operation of the typewriter ribbon drive device constructed as described below will be explained.

Now, FIG. 2 shows the state in which the carbon ribbon cassette 6 is attached to both spool shafts 4 and 5, and the winding spool 8aK on the right is wound with the used carbon ribbon 10. At the same time, an unused carbon ribbon 10 is wound around the supply spool 81 on the left side. At this time, as shown in FIG. 1, the right pawl member 28 engages with the corresponding mold wheel 41), the right spool shaft 4 becomes the winding side, and the left pawl member 28 engages with the corresponding mold wheel 41). The left spool shaft 5 separated from the corresponding model wheel 51 is on the supply side.

In this state, as the printing mechanism of the typewriter operates, a carbon ribbon feed roller (not shown) is rotated by a predetermined amount, and the drive lever 22 and the interlocking lever 25 are rotated back and forth via the connecting rod 24.
The claw member 28 is reciprocated back and forth, and the corresponding spool shaft 4 is rotated counterclockwise by a predetermined amount by the right claw member 28.

Therefore, the carbon ribbon is pulled out from the carbon ribbon base (0 is the supply spool 81 by a predetermined amount for each operation of the printing mechanism) provided between the spools 3a and 9b (0 is the supply spool 81 by the cooperation of the carbon ribbon feed roller and the ribbon press roller). is sent to the right along the printing position on the front of the platen, and
It is wound onto the take-up spool 8a.

When installing this carbon ribbon cassette 6, as shown in FIG.
is fitted into the support cylinder portion 20 of the cassette 6 in a non-contact state, so that the spring force of the compression spring 18 is maintained at a predetermined value.
The second braking device 19 is in a state of applying a weaker braking force to the spool shaft 5 than the first braking device 15 on the winding side. Therefore, the spool shaft 5 on the supply side allows the slight amount of feeding of the ribbon 10 caused by the printing element pressing the carbon ribbon 10 against the printing position on the platen surface during printing. Therefore, it is possible to avoid the situation where the carbon ribbon 10, which has been stretched once as the printing element moves forward, is rewound to the supply spool shaft 4 side while being in contact with the printing paper during the backward movement of the printing element. It is possible to prevent dirt from occurring.

On the other hand, FIG. 3 shows a state in which the cloth ribbon cassette 7 is attached to both spool shafts 4 and 5. In this case, the collar 17 of the second braking device 19 comes into contact with the lower surface of the operating lever 21 provided on one spool 9b of the cloth ribbon cassette 7 and is moved downward, and the compression spring 1B is compressed. In this state, strongly press the spool shaft 5 downward. Therefore, the braking force applied by the second braking device 19 to the spool shaft 5 is strengthened compared to when the carbon ribbon cassette 6 described above is installed, and is stronger than that of the first braking device 15 on the other spool shaft 4 side. be equivalent. Therefore, when the printing element presses the cloth ribbon 11 against the printing position on the platen surface during printing, the spool 91 on the supply side moves loose and the cloth ribbon 11 becomes slack, and the slack cloth is ribbon 1
There is no fear that 1 will separate from the vibrator,
By applying appropriate tension to the cloth ribbon 11, smooth ribbon feeding can be performed.

By the way, FIG. 3 shows a state in which winding of the right spool 9a of the cloth ribbon force center 7 has been completed, and in this state, the switching mechanism operates as described above, and the cloth ribbon 1
The winding direction of No. 1 is switched.

In this case, since both the spool shafts 4 and 5 are driven and driven, the cloth ribbon 11 can be fed smoothly without slack, as in the case described above.

In this way, in the ribbon drive device of this embodiment,
Since a braking device for braking the rotation of each spool shaft 4.5 is provided on the typewriter side, there is no need to provide a special braking mechanism for the carbon ribbon cassette 6 or cloth ribbon cassette 7, and these can be used interchangeably. There is no risk of increasing the cost of the ribbon cassette.

Note that the present invention is not limited to the above-mentioned embodiments, and each part may be modified without departing from the spirit of the present invention, for example, the second brake member may be configured with a leaf spring instead of the compression spring 18. The configuration can also be changed arbitrarily.

Effects As detailed above, according to the present invention, when a carbon ribbon cassette is used, it is possible to prevent print smudges and obtain clear prints, and when a cloth ribbon cassette is used, it is possible to prevent the slack of the cloth ribbon during printing. This has an excellent effect of eliminating ribbon jams and avoiding ribbon jams.

[Brief explanation of drawings]

Fig. 1 is a plan view showing a ribbon drive device of a typewriter embodying the present invention, Fig. 2 is a sectional view taken along the line 11-■ in Fig. 1 with a carbon ribbon cassette attached, and Fig. 3 is a plan view showing the ribbon drive device of a typewriter embodying the present invention. FIG. 3 is a sectional view of a state in which a cloth ribbon cassette is attached. Substrate 1, support shafts 2, 3, spool shafts 4, 5, carbon ribbon cassette 6, cloth ribbon force center 7, carbon ribbon spool Ba, 81], cloth ribbon spool 9a
,,91), carbon ribbon 10, cloth ribbon 11, first
Braking device 15, second braking device 19゜Patent applicant Brother Industries, Ltd. Agent Patent attorney Hironobu Onda

Claims (1)

[Claims] 1. A pair of support shafts (2°3) fixed on the substrate (1)
A pair of spools (13a, Bb, Bb,
9a, 9111 [connected, -, , 5(7), 7°-
7,4,ゎ8y+)My (10) In the ribbon drive device that winds the cloth ribbon (11) onto the other spool, the winding spool (8a) of the carbon ribbon cassette (6)
) and a first braking device (15) that is provided between the drive member (4) connected to the support shaft (2) and always brakes the rotation of the drive member (4), and a carbon ribbon cassette ( 6
) on the side connected to the supply spool (8b) of the drive section 4.
J' (5) and the support shaft (3), and when the carbon ribbon cassette (6) is installed, the braking force for the driving member (5) K is applied to the first braking device (15).
) is weaker than that of the first braking device (
15) and a second braking device (
19) A typewriter ribbon drive device having: