JPH0764109B2 - Ink ribbon cassette - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ink ribbon cassette used in a printer such as a typewriter.

(Conventional example) Of the ink ribbon cassettes, FIG. 3 shows an ink ribbon cassette using a fabric type ribbon. In FIG. 3, an endless fabric ribbon 2 is stored in the storage portion 1a in the case 1. The ribbon pulled out from the storage portion 1a is pressed against the inner wall 1b by the tension spring 3 in the portion A, and then pulled out to the outside.

The ink ribbon sandwiched between the push wheel 4 and the gear portion (not shown) of the cassette knob 5 is drawn in the direction a by the rotation of the cassette knob in the direction of the arrow, and is stored in the storage portion 1a again.

(Problems to be Solved by the Invention) However, in the related art, when the ink ribbon is slightly pulled out and separated, slack occurs. In the conventional type, the surface of the ink ribbon is always rubbed by the tension spring, so the ribbon is easily scratched, and in the case of a fabric ribbon, the ink is squeezed by the tension spring, and the accumulated ink is collected once in a ribbon. Since it is carried by and comes out, it is easy for the density of printing to vary.

(Means for Solving the Problem) The present invention includes a housing, an ink ribbon housing portion that is provided in the housing for housing an ink ribbon, and a drawer portion that pulls out the ink ribbon to the outside of the housing. In the ink ribbon cassette provided, a boss arranged to be press-contactable to the ink ribbon between the ink ribbon storage portion and the pull-out portion, and arranged between the ink ribbon storage portion and the pull-out portion, A lock claw that restricts the conveyance of the ink ribbon by pressing the boss via the ink ribbon, a first elastic member for pressing the lock claw against the boss, the lock claw, and the ink. The lock release lever, which releases pressure contact with the ribbon to release the regulation of conveyance of the ink ribbon by the lock claw, is arranged between the lock claw and the drawer, A roller that guides the ribbon, and a tip that acts on the lock release lever to release the regulation of conveyance of the ink ribbon by the lock claw, and according to a change in tension of the ink ribbon that acts on the roller, A tension lever displaceable between a working position where the tip acts on the lock release lever and a separated position where the tip separates from the lock release lever; and the ink ribbon formed by the lock release lever by the lock claw. A second elastic member for displacing the tension lever to the separated position against the tension of the ink ribbon acting on the roller when the pressure contact of the tension lever is released. The action position is caused by the tension of the ink ribbon that is pulled out of the casing by being regulated by the boss and the lock claw. Wherein the transport regulation of the ink ribbon displaced by first
The release of the ink ribbon against the elastic force of the elastic member and the displacement of the ink ribbon by the elastic force of the second elastic member in response to the release to restrict the transport of the ink ribbon, thereby transporting the ink ribbon. The above problem is solved by making it possible to repeat the regulation and the release of the transportation regulation.

(Operation) In the ink ribbon cassette of the present invention configured as described above, the slack ink ribbon pulled out of the housing of the ink ribbon cassette is regulated by the pressing of the lock claw and the boss, It is drawn into the housing through a roller provided on a tension lever that is displaced to the separated position by the elastic force of the second elastic member.

Further, when the ink ribbon is pulled out of the housing by being regulated to be conveyed by the boss and the lock claw, the tension lever is displaced to the working position by the tension of the ink ribbon pulled out of the housing. By this displacement of the tension lever, the lock release lever releases the pressing of the ink ribbon by the lock claw and the boss against the elastic force of the first elastic member. Then, in response to the release, the tension lever is displaced to the separated position by the elastic force of the second elastic member. Depending on the displacement between the acting position and the separated position of the tension lever, the regulation of the conveyance of the ink ribbon and the release of the regulation of the conveyance are repeated.

(Embodiment) FIG. 1 shows an embodiment of the present invention. Reference numeral 11 denotes a ribbon case as a casing in the present invention, which is composed of an upper case and a lower case, and an ink ribbon 2 which is irregularly superposed on a storage portion 11a. To store. The ink ribbon in the storage portion 11a is pulled out from the opening 11b, and is a spring as the first elastic member in the present invention.
It is pressed against the boss 15 by the lock claw 14 which is urged to rotate in the direction b around the shaft 13 by the shaft 12. 16 is a tension lever, and the tip of the tension lever 16 is centered around the shaft 17.
It is possible to rotate between a position where 16a contacts the lock release lever 21 and a position where the tension lever 16 contacts the stopper 19. In addition, as will be described later in detail, when a large amount of ink ribbon 2 is pulled out of the ribbon case 11 at a time, or when a large amount of ink ribbon 2 is pulled out of the storage portion 11a at a time, tension is applied. Lever 16 is stopper 19
Abut.

A roller for guiding the ribbon is attached to the tip of the tension lever 16.
20 are provided. Reference numeral 21 denotes a lock release lever for releasing the lock of the lock claw 14, which is rotatable around a shaft 22 and rotates in conjunction with the lock claw 14 by a pin 23.

The ink ribbon is guided by the pair of arms 24 and 25 so as to be exposed to the outside, and further, the pressing gear 26 and the cassette knob are used.
It is meshed and sandwiched between 27 gear parts (not shown), and again the storage part
Guided into 11a. Reference numeral 28 denotes a holder holding the pressing gear 26, which is biased by a spring 29 toward the cassette knob 27.

Next, the operation will be described.

The ink ribbon cassette of this embodiment has an arm 24 and an arm.
It is used by placing it on a carriage so that the recording head is positioned between the ink ribbon 2 and the ink ribbon cassette 25.
May get caught in the recording head or carriage.
At this time, as will be described later in detail, the movement of the ink ribbon 2 is restricted by the pressing force of the lock claw 14 and the boss 15. However, since the force for hooking the ink ribbon 2 on the head or the like and pulling it out from the case 11 is usually larger than the pressing force, the ink ribbon 2 is stored in the storage portion.
It will be pulled out from 11a. After that, the ink ribbon 2
When the force for pulling the blade out of the case 11 disappears, the tension lever 16 rotates clockwise in FIG. 1 due to the elastic force of the spring 18 as the second elastic member in the present invention. At this time, since the ink ribbon 2 is regulated by the pressing force of the lock claw 14 and the boss 15, the tension of the tension lever 16 in the clockwise direction causes the roller 20 to rotate.
The amount of the ink ribbon 2 corresponding to the displacement of the tension lever 16 is drawn into the case 11 via the.

At that time, if the amount of the ink ribbon 2 pulled out is equal to or more than a predetermined amount, the tension lever 16 is
The tip 16a of 16 moves from a position where it can contact the lock release lever 21 to a position where the tension lever 16 contacts the stopper 19 (the position shown by the solid line in FIG. 2).

That is, in FIG. 2, when a force for pulling the ribbon to the outside in some form acts on the ribbon, the lock claw 14 always locks the ribbon, and as a result, the tension lever 16 moves to the position shown by the solid line in FIG. From the direction indicated by the two-dot chain line (direction c). However, the tension lever 16 always has a force to rotate in the direction opposite to the c direction due to the spring 18, and the tension lever 16 is
At the same time when the force of pulling out to the outside disappears, the ink ribbon is rotated in the direction returning to the position indicated by the solid line to pull the ink ribbon into the case 11 to remove the slack of the ink ribbon.

Further, the pressing of the ink ribbon 2 by the lock claw 14 and the boss 15 which will be described later is released, and the lock claw 14 and the boss 15 are released again.
Until the ink ribbon 2 is pressed by
In some cases, the amount of the ink ribbon pulled out from the ink ribbon storage unit 11a is larger than the normal pulling amount. The ink ribbons are folded in a small size and stored densely in the ink ribbon storage portion 11a. The ink ribbons 2 that are drawn out from the openings 11b and the ink ribbons 2 that are folded adjacent to the ink ribbons are May move together and be pulled out from the opening 11b. When the ink ribbon 2 is further pulled out in this state, the entire portion of the ink ribbon 2 in the folded state described above is also pulled out of the ink containing portion 11a. Then, as will be described later in detail, before the pressing of the ink ribbon 2 by the lock claw 14 and the boss 15 is released and the pressing of the ink ribbon 2 is performed again, the amount of the ink ribbon 2 that is larger than the normal withdrawal amount is increased. , A slight gap formed between the lock claw 14 and the boss 15 is passed. Depending on the length of the ink ribbon 2 that exceeds the normal pull-out amount, the tension lever 16 is located below the normal position, that is, the stopper 19
It will rotate to a position close to. Therefore, the lock claw
The pressure of the ink ribbon 2 by 14 and the boss 15 is released,
If a certain amount of the ink ribbon 2 that exceeds the normal amount is pulled out before the ink ribbon 2 is pressed again, the tension lever 16 comes into contact with the stopper 19.

Next, the operation of each member when the ink ribbon cassette is actually placed on the carriage and recording is started will be sequentially described with reference to FIGS. 1 and 2.

Rotation of the tension lever toward the lock release claw contact position (counterclockwise in FIG. 2).

When the cassette is actually placed on the carriage and recording is started, the ink ribbon 2 is pulled out from the vicinity of the arm 24 of the case 11. At this time, since the movement of the ink ribbon 2 is restricted by the pressing force of the lock claw 14 and the boss 15, the tension lever 16 tries to pull out the ink ribbon 2 acting on the roller 20 against the elastic force of the spring 18. It rotates counterclockwise by the force.

Then, the counterclockwise rotation causes the tension lever 16 to reach a position where the tip 16a abuts the lock release lever 21.

The two-dot chain line tension lever 16 in FIG. 2 represents this state.

Ink ribbon transport regulation release operation by contact between the tension lever and the lock release claw.

When the ink ribbon 2 is subsequently pulled out from the vicinity of the arm 24 of the case 11, the tension lever 16 is further displaced upward in FIG.
Is rotated counterclockwise with respect to the shaft 22. At this time,
The lock release lever 21 rotates against the elastic force of the spring 12.

Further, since the lock release lever 21 and the lock claw 14 are interlocked by the pin 23 and rotate in opposite directions, the lock claw 14
The shaft 14 rotates in a clockwise direction with respect to the shaft 13.

By rotating the lock claw 14 clockwise,
The pressing of the ink ribbon 2 by 14 and the boss 15 is released.

Then, with respect to the tip 16a, the storage portion 11a in the ink ribbon 2
Since there is no restriction in the lateral direction, the tension lever 16
The elastic force of the spring 18 enables clockwise rotation.

Rotation of the tension lever in the stopper contact position direction (clockwise direction in FIG. 2).

The tension lever 16 starts to rotate in the clockwise direction by the elastic force of the spring 18 with the release of the regulation of the portion of the ink ribbon 2 on the side of the containing portion 11a.

By the rotation of the tension lever 16, the contact between the tip 16a and the lock release lever 21 is released. And spring 12
2 causes the pin 23 to be displaced upward in FIG. 2 to rotate the lock release lever 21 in the clockwise direction and the lock pawl 14 in the counterclockwise direction. By rotating the lock claw 14 in the counterclockwise direction, the lock claw 14
Presses the ink ribbon 2 together with the boss 15.

The ink ribbon 2 is regulated by the pressing force of the lock claw 14 and the boss 15 as well as the force of pulling the ink ribbon 2 out of the case 11. Therefore, the clockwise rotation of the tension lever 16 due to the elastic force of the spring 18 is stopped.

The clockwise rotation stop position of the tension lever 16 at this time is determined by the elastic force of the spring 12 and the elastic force of the spring 18. That is, the larger the elastic force of the spring 18, the closer the rotation stop position of the tension lever 16 is to the stopper 19,
Also, the greater the elastic force of the spring 12, the more the tension lever 16
The rotation stop position of is close to the lock release lever 21.

On the other hand, the force of pulling out the ink ribbon 2 to the outside of the case 11 acts on the tension lever 16 via the roller 20 that guides the ink ribbon 2, thereby acting as a brake against the clockwise rotation of the tension lever 16. You can However, from the first term to the second term, since the pressing of the ink ribbon 2 by the lock claw 14 and the boss 15 is released, the movement of the ink ribbon 2 is not regulated. Therefore, the ink ribbon 2 is pulled out from the storage portion 11a according to the magnitude of the force for pulling the ink ribbon 2 out of the case 11. Therefore, the ink ribbon 2 goes out of the case 11.
The magnitude of the force for pulling out does not affect the rotation stop position of the tension lever 16 in the clockwise direction as much as the spring 12 and the spring 18.

Re-rotation operation of the tension lever in the lock release claw contact position direction (counterclockwise direction in FIG. 2).

Next, the contact between the tip 16a and the lock release lever 21 is released, and the lock claw 14 and the boss 15 press the ink ribbon 2 again to restrict the movement of the ink ribbon 2. for that reason,
The tension lever 16 is a roller that resists the elastic force of the spring 18.
The force acting on the ink ribbon 2 to pull out the ink ribbon 2 causes the ink ribbon 2 to rotate counterclockwise. By this counterclockwise rotation, the tension lever 16 reaches the position where the tip 16a abuts the lock release lever 21 (the above-mentioned item).

As described above in detail, the tension lever 16 returns from the state of the item (3) to the state of the item (2), and thereafter, as the recording is continued, the state of the item (1) → the state of the item (2) → the state of the item (2) → the state of the item (2) → State of item → State of item is repeated sequentially.

That is, when the cassette knob 27 actually starts to rotate and the ribbon winding starts, the tension lever 16 gradually moves to c.
Rotate in the direction. Tension lever 16 at the position indicated by the chain double-dashed line
When is reached, the tip end 16a of the tension lever 16 is just in contact with the lock release lever 21. As a result, as it further rotates in the direction c, the contacting lock release lever 21 starts to rotate about the shaft 22, and at the same time, the lock claw 14 is pushed by the pin 23 protruding from the lock release lever 21 itself to rotate. The ribbon lock is released.

When the lock claw 14 is separated from the ribbon in this way, the ink ribbon in the storage portion 11a is pulled out, and the tension lever 16 rotates again in the direction opposite to the c direction to bring the lock claw 14 into contact with the ink ribbon and lock it. Let The ink ribbon is fed by repeating such contact, release, and contact between the lock claw and the ink ribbon 2. Therefore, no excessive tension is applied to the ink ribbon. In addition, the lock lever 14 does not squeeze the ink ribbon,
Do not rub the ink ribbon. Therefore, the ribbon is less damaged and is preferable not only when using a fabric ribbon but also when using a carbon ribbon or the like. In addition, since the ribbon is not squeezed, ink is not accumulated, and it is difficult to cause shading of printing.

(Effect) As described in detail above, according to the present invention, it is possible to obtain an ink ribbon cassette that does not leave the ink ribbon in a slackened state even when the ink ribbon is pulled out of the housing.

Further, when the ink ribbon is conveyed, an excessive tension is not applied to the ink ribbon, so that an ink ribbon cassette that does not damage the ink ribbon can be obtained. Further, since the ink ribbon is not squeezed, the ink is not stored and it is possible to obtain the ink ribbon cassette which does not generate the light and shade of printing.

[Brief description of drawings]

 FIG. 1 is a broken sectional view of an embodiment of the present invention, FIG. 2 is an explanatory view of a tension mechanism, and FIG. 3 is a sectional view of a conventional example. 2 ... Ink ribbon 11a ... Storage section 14 ... Lock claw 15 ... Boss 16 ... Tension lever 18 ... Spring 21 ... Lock release lever

Claims (1)

[Claims] 1. An ink ribbon cassette comprising: a housing; an ink ribbon housing portion provided in the housing for housing an ink ribbon; and a drawer portion for drawing the ink ribbon out of the housing. A boss disposed so as to be capable of being pressed against the ink ribbon between the ribbon storage portion and the pull-out portion, and disposed between the ink ribbon storage portion and the pull-out portion,
A lock claw for restricting the conveyance of the ink ribbon by pressing the boss via the ink ribbon, and a first for pressing the lock claw against the boss.
An elastic member, a lock release lever that releases pressure contact between the lock claw and the ink ribbon to release the regulation of conveyance of the ink ribbon by the lock claw, and is arranged between the lock claw and the drawer portion, A roller that guides the ink ribbon, and a tip that acts on the lock release lever to release the regulation of conveyance of the ink ribbon by the lock claw, and responds to a change in tension of the ink ribbon that acts on the roller. A tension lever displaceable between an operating position where the tip acts on the lock release lever and a separated position where the tip separates from the lock release lever; When the pressure contact of the ink ribbon is released, the tension lever is moved against the tension of the ink ribbon acting on the roller. A second elastic member for displacing to the separated position, and the tension lever is moved to the acting position by the tension of the ink ribbon that is conveyed and regulated by the boss and the lock claw and pulled out of the housing. The ink ribbon is displaced to release the regulation of conveyance of the ink ribbon against the elastic force of the first elastic member, and in response to the release, the elastic force of the second elastic member is displaced to the separated position to move the ink ribbon. By regulating the conveyance of the ink ribbon, it is possible to repeat the conveyance regulation of the ink ribbon and the release of the conveyance regulation.