JPH0825768A - Ribbon cassette - Google Patents

Abstract

PURPOSE:To suitably feed an ink ribbon without slack or wrinkle by applying a back tension to the ribbon via the clutch action of a clutch spring disposed in a ribbon supply spool. CONSTITUTION:A rotary member 31 is engaged within a ribbon supply spool 2 rotatably supported in the cassette case 11 of a ribbon cassette, and the circular ring part 32 of the spring 32 is engaged with the periphery of the protrusion 32a of the member 31. The locking part 32b of the spring 32 is locked to a locking groove 33b provided at the cylindrical part 33a of a spool pressing member 33 integral with the case 11. When the spool 2 is rotated in an ink ribbon feeding direction, the part 32 is extended in its diameter to smoothly rotate the spool 2. When the spool 2 is reversely rotated, the part 32 is reduced in its diameter to slightly reversely rotate the spool 2 by the elastic restoring force of the part 32b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a ribbon cassette incorporating a ribbon supply spool around which an ink ribbon is wound and a ribbon take-up spool around which an ink ribbon is drawn out from the ribbon supply spool and wound up, and particularly, via a clutch action of a clutch spring arranged in the ribbon supply spool. The present invention relates to a ribbon cassette capable of appropriately feeding an ink ribbon without causing slack or wrinkles by applying back tension to the ink ribbon.

[0002]

2. Description of the Related Art Conventionally, in a tape printing apparatus for printing characters such as characters on a printing tape which is a long printing medium, a printing tape and an ink ribbon for printing on the printing tape have a predetermined shape. The ribbon cassette housed in the cassette case is attached to the printing mechanism, and characters and the like are printed through the thermal head in a state where the printing tape supplied from the ribbon cassette and the ink ribbon are superposed on each other. . In such a tape cassette, an ink ribbon is wound around a ribbon supply spool to be housed, and a ribbon take-up spool that winds up and collects a used ink ribbon is provided. The ribbon take-up spool is rotated to drive the ribbon supply spool. The required amount of ink ribbon is pulled out from the printer for printing. Further, in a word processor or the like, a ribbon cassette in which an ink ribbon is housed in a cassette case having a predetermined shape is used.

In these tape cassettes or ribbon cassettes (generally referred to as "ribbon cassettes" hereinafter), the ribbon supply spool for winding the ink ribbon before use is not positively driven, and the ribbon take-up spool is used. It was only passively driven to rotate as the ink ribbon was pulled out. On the other hand, because the ink ribbon is not pulled out at a constant speed,
It was common to provide some braking means on the ribbon supply spool. If the rotation of the ribbon supply spool cannot follow the fluctuation of the ink ribbon drawing speed due to inertia,
This is because wrinkles and slacks will occur in the pulled out ink ribbon, which will lead to problems such as unclear printing, misalignment, or straying ink ribbons getting caught in other parts. Further, the braking means also plays a role of giving a certain tension to the ink ribbon until it is pulled out from the ribbon supply spool and inserted into the thermal head.

FIG. 4 shows an example of a braking means for a ribbon supply spool in a conventional ribbon cassette, which uses a screw coil spring. FIG. 4 is a sectional view of a ribbon supply spool 80 of a conventional ribbon cassette. In FIG. 4, a bearing 82 is formed as a part of the cassette case 81 of the ribbon cassette. The inside of the bearing 82 is hollow, and a part of the bearing 82 is a window 83. A cylindrical ribbon supply spool 80 around which an ink ribbon 86 is wound is fitted into the bearing 82. Then, in the inner cavity of the bearing 82, the torsion coil spring 84
Is inserted in a compressed state. A bent portion 85 is provided at one end of the torsion coil spring 84, and the bent portion 8
5 is in point contact with the inner surface of the ribbon supply spool 80 through the window 83 of the bearing 82.

In such a configuration, since there is a certain clearance between the outer diameter of the bearing 82 and the inner diameter of the ribbon supply spool 80, the ribbon supply spool 80 can essentially rotate freely and the ink ribbon 86 can be pulled out. It rotates as it is played. However, it receives resistance due to contact friction with the bent portion 85 of the torsion coil spring 84 which is about to expand. Therefore, the ribbon supply spool 80 is braked by its contact resistance when the drawing speed of the ink ribbon 86 becomes slow. This also allows the ink ribbon 86
It prevents the occurrence of slack and gives tension.
Further, as another example of braking the ribbon supply spool,
There is also a method in which a washer is fixed in the cassette case while being in contact with the ribbon supply spool, and the rotation of the ribbon supply spool is braked by a frictional force generated between the washer and the ribbon supply spool.

[0006]

However, in the method using the above-mentioned torsion coil spring 84, the bent portion 85 of the torsion coil spring 84 is substantially in point contact with the inner wall of the ribbon supply spool 80, and therefore the bent portion 85 and The frictional force generated between the ribbon supply spool 80 and the inner wall of the ribbon supply spool 80 tends to be unstable. As a result, it is difficult to always apply a stable back tension to the ink ribbon 86, and depending on the state in which the back tension is applied, the ink ribbon 86 may be loosened or wrinkled.

Further, as described above, when the rotation of the ribbon supply spool is braked by the frictional force generated between the washer fixed in the cassette case and the ribbon supply spool, it can be applied to the ink ribbon. Since there is a limit to the back tension and it can be an effective method for an ink ribbon with a small ribbon width, when using an ink ribbon with a relatively wide width, it is necessary to make the ink ribbon run stably. There is a problem that a suitable back tension cannot be given.

The present invention has been made to solve the above-mentioned problems, and the back tension is applied to the ink ribbon through the clutch action of the clutch spring arranged in the ribbon supply spool, so that the slack is obtained. You can feed the ink ribbon properly without wrinkles and
An object of the present invention is to provide a ribbon cassette that eliminates defects caused by slack of an ink ribbon or wrinkles and enables good printing, and that can easily assemble a ribbon supply spool and a clutch spring. To do.

[0009]

To achieve the above object, the present invention provides a ribbon supply spool in which an ink ribbon is wound in a cassette case, and a ribbon take-up in which the ink ribbon is drawn and taken up from the ribbon supply spool. In a ribbon cassette in which the spool and the rotatably arranged,
A rotary member that is inserted into the ribbon supply spool and is rotated integrally with the ribbon supply spool, and is formed integrally with the cassette case and a rotating member having a cylindrical protrusion at the upper end, and is rotated upward in the ribbon supply spool. A spool pressing member having a tubular portion to be fitted more, and a plurality of engaging grooves formed in the tubular portion, a coil-shaped annular portion, and an engagement extending from the annular portion A clutch spring having a portion, the annular portion of the clutch spring is fitted to the cylindrical protrusion of the rotating member, and the locking portion is formed on the cylindrical portion of the spool pressing member. It has a configuration in which it is locked in one of the locking grooves. Further, the annular portion of the clutch spring is expanded in diameter when a force in the ink ribbon withdrawing direction by the ribbon take-up spool acts on the ink ribbon, and when a force in a direction opposite to the ink ribbon withdrawing direction acts. Is reduced in diameter.

[0010]

In the ribbon cassette of the present invention having the above-mentioned structure, when the ribbon cassette is mounted on the printing device to print characters or the like, the operation of the ribbon take-up spool causes
The ink ribbon is pulled out from the ribbon supply spool and is wound up on the ribbon take-up spool. At this time,
The coiled annular portion of the clutch spring is fitted to the cylindrical protrusion of the rotating member fitted in the ribbon supply spool, and the engaging portion of the clutch spring is formed on the tubular portion of the spool pressing member. It is locked in one of the locking grooves, and when the ink ribbon is pulled out by the ribbon take-up spool, the force in the ink ribbon pull-out direction acts on the ink ribbon to expand the diameter of the annular portion. It Therefore, the connection between the clutch spring and the ribbon supply spool is released, whereby the ribbon supply spool is rotated while applying a predetermined back tension, and the ink ribbon is stably fed without being fed more than necessary. , Sent properly.

Further, during non-printing, the rotation of the ribbon take-up spool is stopped, and the ink ribbon take-up operation is stopped. At this time, a force in the direction opposite to the ink ribbon withdrawing direction acts on the ink ribbon via the elastic force of the clutch spring, whereby the annular portion of the clutch spring is reduced in diameter and the cylindrical protrusion of the rotating member. Wrap around the area. Therefore,
The clutch spring and the ribbon supply spool are connected to each other, and based on this, the ribbon supply spool is slightly reverse-rotated in the direction opposite to the ink ribbon pull-out direction through the elastic force of the clutch spring, so that the ink ribbon is not loosened. The wrinkles are surely prevented from occurring.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The ribbon cassette of the present invention will be described below with reference to the drawings based on an embodiment embodied in a tape cassette for a tape printer for printing on a long print tape. The internal structure of the tape cassette 1 of this embodiment is shown in FIG. The tape cassette 1 includes a pair of upper and lower cassette cases 11 (only the lower cassette case 11 is shown in FIG. 1) formed of resin or the like in a substantially rectangular parallelepiped shape, and a transparent tape 12 and a transparent tape 12 which are print target media. Ink ribbon 13 for printing on a transparent tape 12
A colored double-sided pressure-sensitive adhesive tape 14 to be attached to the back of the ink is wound around a spool and stored, and a ribbon take-up spool 16 for taking up the used ink ribbon 13 is also provided.

The transparent tape 12 is the transparent tape spool 1.
It is wound around 5 and stored. Transparent tape spool 1
The transparent tape 12 pulled out from the
After passing through the opening 22 of the ribbon cassette 1, it is guided to the tape drive roller 19 which is rotationally driven by a tape printer (not shown) and reaches the outside of the tape cassette 1.

The end of the ink ribbon 13 is joined to the ribbon supply spool 2 and is wound and stored.
Ink ribbon 1 pulled out from ribbon supply spool 2
3 is overlapped with the transparent tape 12, and the transparent tape 12
And passes through the opening 22. Then, clear tape 12
The tape take-up spool 16 is separated from the ribbon guide 26 and the auxiliary guide 25 to reach the ribbon take-up spool 16 which is rotationally driven by the tape printer. The starting end of the ink ribbon 13 is joined to the ribbon take-up spool 16 and taken up. Inside the ribbon supply spool 2, as will be described later, a spool support portion 30 provided upright on the bottom wall of the lower cassette case 11,
A rotating member 31, which is rotatable with the ribbon supply spool 2 on the spool supporting portion 30, a spool pressing member 33 hung from the upper wall of the upper cassette case 11, and a rotating member 3.
A clutch spring 32 arranged between 1 and the spool pressing member 33 is stored and arranged. Note that such a configuration will be described later in detail with reference to FIG. Inner teeth 18 are formed inside the ribbon take-up spool 16. The inner teeth 18 are fitted to the rotary drive end of the printing device when the tape cassette 1 is mounted on the printing device. Internal tooth 1
The ribbon take-up spool 16 is rotated by driving 8 of the printer.

The colored double-sided pressure-sensitive adhesive tape 14 is housed by being wound around a double-sided tape spool 17 with the release paper on the outside with the release paper on one side. Colored double-sided adhesive tape 1 pulled out from double-sided tape spool 17
4 is guided to the tape drive roller 19, and the adhesive surface on the side where the release paper is not superposed is attached to the transparent tape 12. And the tape cassette 1 together with the transparent tape 12
To the outside.

A printing mechanism of the tape printer is located in the opening 22 of the tape cassette 1 when the tape cassette 1 is mounted in the tape printer. The printing mechanism of the tape printer has a platen roller (not shown) that presses the ink ribbon 13 and the transparent tape 12 on a thermal head (not shown). With these, the ink ribbon 13
Printing is performed on the transparent tape 12 overlaid with. The tape printer has a function of slightly feeding the ink ribbon 13 and the transparent tape 12 in reverse by the tape drive roller 19 to adjust the margin when the text is printed.

A tape cassette 1 having the above-mentioned overall structure
When printing, the ribbon take-up spool 16 has internal teeth 18
It is rotationally driven from the side of the tape printer via the. Further, the tape drive roller 19 is also rotationally driven by the tape printer. A driven roller (not shown) is arranged at a position facing the tape drive roller 19 on the side of the tape printer, and when the tape cassette 1 is mounted in the tape printer, the tape drive roller 19 and the driven roller are separated from each other. The transparent tape 12 and the colored double-sided adhesive tape 14 are sandwiched in a state of being overlapped. Then, by driving the tape driving roller 19, the transparent tape 12 is pulled out from the transparent tape spool 15, and the colored double-sided adhesive tape 14 is pulled out from the double-sided tape spool 17. The transparent tape spool 15 and the double-sided tape spool 17 are
The tape rotates as much as it is pulled out.

The ribbon take-up spool 16 is shown in FIG.
By being driven counterclockwise, the ink ribbon 13
Is pulled out from the ribbon supply spool 2. The ribbon supply spool 2 rotates counterclockwise as much as the ink ribbon 13 is pulled out. The platen roller is configured to rotate and drive in synchronization with the ribbon take-up spool 16 and the tape drive roller 19, and the ink ribbon 13 includes the thermal head and the platen roller so that the transparent tape 12 is formed.
It is also possible to adopt a configuration in which the ribbon is delivered by the rotation of the platen roller while being sandwiched in the state of being overlapped with the sheet, and the delivered portion is wound up on the ribbon take-up spool 16.

The ribbon supply spool 2 and its internal structure in the tape cassette 1 are shown in FIGS.
It will be explained based on. Here, FIG. 2 is a cross-sectional view of the ribbon supply spool 2, and FIG. 3 is an exploded perspective view of the ribbon supply spool 2. 2 and 3, a spool support portion 30 having a support shaft 30a is integrally formed on the upper surface of the bottom wall of the lower cassette case 11, and the ink ribbon 13 is wound around the spool support portion 30. The rotated ribbon supply spool 2 is fitted with a certain clearance. A pair of sliding grooves 2a are formed in the inner wall of the ribbon supply spool 2 at positions facing each other.

Inside the ribbon supply spool 2, a rotary member 31 is fitted and arranged above the spool support portion 30. Here, the rotating member 31 has a pair of protrusions 31b formed on the outer peripheral wall thereof, and a cylindrical protrusion 31a formed on the upper end surface thereof. The ribs 31b are inserted in the sliding grooves 2a of the ribbon supply spool 2, so that the rotary member 31 cooperates with the ribs 31b and the sliding grooves 2a to cause the rotating member 31 to move. It becomes possible to rotate integrally with. Further, the support shaft 3 of the spool support 30 is attached to the cylindrical protrusion 31a.
0a is inserted, so that the support shaft 30a is
When the rotating member 31 rotates, the rotating member 31 and the spool supporting portion 30 are properly held in a positional relationship. Further, a spool pressing member 33 is provided on the lower surface of the upper wall of the upper cassette case 11, and the spool pressing member 33 is integrally formed with a cylindrical portion 33a having a plurality of locking grooves 33b formed around the spool pressing member 33. Is formed in.

Further, the cylindrical protrusion 3 of the rotating member 31.
A clutch spring 32 is arranged between 1a and the cylindrical portion 33a of the spool pressing member 33. That is, the clutch spring 32 has a coil-shaped annular portion 32a and a locking portion 32b extending from the annular portion 32a. In the clutch spring 32, the annular portion 32a has a cylindrical protrusion 31a.
It is fitted between the rotary member 31 and the spool pressing member 33 by locking the locking portion 32b in one of the locking grooves 33b. Here, the annular portion 32a is unwound and expanded in diameter when a force in the ink ribbon withdrawing direction acts via the ribbon take-up spool 16, whereby the clutch spring 32 and the ribbon supply spool 2 are separated from each other. The consolidation is released. As a result, the ribbon supply spool 2 becomes rotatable. Further, the annular portion 32a is reduced in diameter when a force in the direction opposite to the ink ribbon withdrawing direction is applied, whereby the clutch spring 32 is formed.
And the ribbon supply spool 2 are connected. As a result, the ribbon supply spool 2 is slightly rotated in the direction opposite to the ink ribbon withdrawing direction via the elastic force accumulated in the locking portion 32b of the clutch spring 32.

Next, when assembling the tape cassette 1, in order to assemble the ribbon supply spool 2, first, the ribbon supply spool 2 is fitted into the spool support portion 30. Next, the annular portion 32a of the clutch spring 32 is fitted around the cylindrical protrusion 31a of the rotating member 31. The rotary member 31 fitted with the clutch spring 32 is inserted into the sliding groove 2a of the ribbon supply spool 2 so that the protrusion 31b of the rotary member 31 is inserted, and the cylindrical projection 31a is provided on the support shaft 30a. The ribbon supply spool 2 is inserted into the ribbon supply spool 2. Finally, the upper cassette case 11 and the lower cassette case 11 are combined, and the cylindrical portion 33a of the spool pressing member 33 is fitted into the ribbon supply spool 2. At this time, since the plurality of locking grooves 33b are formed in the cylindrical portion 33a, the locking portion 32b of the clutch spring 32 is formed.
Is easily locked in any one of the locking grooves 33b. This makes the ribbon supply spool 2 extremely easy to use.
The parts can be assembled.

Then, the ribbon supply spool 2 and the clutch spring 32 operate as follows. As described above, the annular portion 32a of the clutch spring 32 is mounted on the cylindrical protrusion 31a of the rotating member 31 in a slightly expanded state, so that the cylindrical protrusion 31a of the rotating member 31 is elastically deformed.
It is in close contact with a. Therefore, when the ribbon take-up spool 16 rotates to perform text printing in the thermal head and the ribbon supply spool 2 rotates due to the pulling action of the ink ribbon 13, the clutch spring 32 also tries to rotate accordingly.

However, the engaging portion 32b of the clutch spring 32 is
Is locked in the locking groove 33b of the spool pressing member 33, so that sliding friction is generated between the cylindrical protrusion 31a of the rotating member 31 and the annular portion 32a of the clutch spring 32.
A counterclockwise torque is applied to the annular portion 32a of the clutch spring 32. As a result, the diameter of the annular portion 32a is increased and sliding friction with the cylindrical protrusion 31a of the rotating member 31 is reduced. As a result, the braking action applied to the cylindrical protrusion 31a of the rotating member 31 due to the friction with the annular portion 32a is small, and smooth rotation is possible. At this time, the clutch spring 3
The second locking portion 32b is in an elastically deformed state.

When the printing of the text is completed, the rotation of the ribbon take-up spool 16 is stopped and the force for pulling out the ink ribbon 13 from the ribbon supply spool 2 is reduced. The elastic restoring force of the locking portion 32b of the clutch spring 32 causes the annular portion 32a of the clutch spring 32 to rotate clockwise. This rotation is transmitted to the ribbon supply spool 2 through the cylindrical protrusion 31a of the rotating member 31, so that the ink ribbon 13 that has been slightly reverse-fed is transferred to the ribbon supply spool 2.
It is wound around and prevents wrinkles and slack from occurring.

Here, the engaging portion 32b of the clutch spring 32 is provided.
Is about to elastically recover, the counterclockwise torque applied from the ribbon supply spool 2 to the annular portion 32a of the clutch spring 32 has already disappeared.
The expanded diameter state of a is released and is in close contact with the cylindrical protrusion 31a of the rotating member 31. Therefore, the reverse rotation caused by the back tension is transmitted to the ribbon supply spool 2 through the cylindrical protrusion 31a of the rotating member 31. That is, the clutch spring 32 acts as a one-way clutch according to the applied torque.

As described above, the ink ribbon 13 which has been slightly fed backward can be rewound on the ribbon supply spool 2, and in the next printing, unclear printing due to wrinkles and looseness of the ink ribbon 13 may occur. It is possible to provide an excellent tape cassette 1 which does not have such a structure. In the tape cassette 1, the contact portion between the cylindrical protrusion 31a of the rotating member 31 and the annular portion 32a of the clutch spring 32 is wide,
Since it covers the entire cylindrical protrusion 31a and is substantially close to surface contact, the transmission of rotation by friction from the annular portion 32a to the ribbon supply spool 2 is stable.

As described above in detail, in the tape cassette 1 according to this embodiment, the annular portion 32 of the clutch spring 32 is used.
a is fitted around the cylindrical protrusion 31a of the rotary member 31 fitted into the ribbon supply spool 2, and the engaging portion 32b of the clutch spring 32 is integrally formed with the upper cassette case 11. When the ribbon supply spool 2 is locked in one of the locking grooves 33b provided in the cylindrical portion 33a of the reference numeral 33 and rotates in the ink ribbon feeding direction, the diameter of the annular portion 32a of the clutch spring 32 is increased. Thus, the ribbon supply spool 2 can be smoothly rotated, and when the ribbon supply spool 2 rotates in the direction opposite to the ink ribbon feeding direction, the annular portion 32a of the clutch spring 32 contracts, The ribbon supply spool 2 is slightly rotated in the opposite direction by the elastic restoring force of the engaging portion 32b of the clutch spring 32. As a result, the ink ribbon 13 is slightly rewound, and it is possible to reliably prevent the wrinkles and the slack of the ink ribbon 13 from occurring, and it is possible to prepare for the next printing. As a result, the ink ribbon 13
It is possible to eliminate slack and wrinkles, eliminate printing inconveniences caused by these, and perform good printing.

When the tape cassette 1 is assembled, when the upper cassette case 11 and the lower cassette case 11 are combined to fit the cylindrical portion 33a of the spool pressing member 33 into the ribbon supply spool 2, the spool pressing member 33 is fitted. Since a plurality of engagement grooves 33b are formed in the cylindrical portion 33a of the clutch spring 32, the engagement portion 32b of the clutch spring 32 is formed.
Is easily locked in any one of the locking grooves 33b. This makes it possible to assemble the ribbon supply spool 2 very easily.

The above embodiments do not limit the present invention at all, and it goes without saying that various modifications and improvements can be made without departing from the spirit of the invention. For example, in each of the above-mentioned embodiments, the tape cassette has a print-receiving tape and the like built-in in addition to the ink ribbon. It may be a ribbon cassette for printing on.

[0031]

As is apparent from the above description, according to the ribbon cassette of the present invention, the back tension is applied to the ink ribbon through the clutch action of the clutch spring arranged in the ribbon supply spool. This allows the ink ribbon to be properly fed without causing slack or wrinkling, and eliminates the problems caused by slack or wrinkling of the ink ribbon, and enables good printing, and the ribbon supply spool and clutch. It is possible to provide a ribbon cassette in which the assembly of the spring portion can be easily performed, and the industrial effect thereof is great.

[Brief description of drawings]

FIG. 1 is a plan view showing an internal configuration of a ribbon cassette of this embodiment.

FIG. 2 is a cross-sectional view of a ribbon supply spool of the ribbon cassette of this embodiment.

FIG. 3 is an exploded perspective view of a ribbon supply spool of the ribbon cassette of this embodiment.

FIG. 4 is a cross-sectional view of a ribbon supply spool of a conventional ribbon cassette.

[Explanation of symbols]

 1 Tape Cassette 2 Ribbon Supply Spool 11 Cassette Case 13 Ink Ribbon 16 Ribbon Winding Spool 31 Rotating Member 32a Clutch Spring Annular Portion 32b Clutch Spring Locking Portion 33 Spool Pressing Member 33b Locking Groove

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yutaka Sugiyama 15-1 Naeshiro-cho, Mizuho-ku, Nagoya City Brother Industries, Ltd.

Claims (2)

[Claims] 1. A ribbon cassette in which a ribbon supply spool around which an ink ribbon is wound, and a ribbon take-up spool around which an ink ribbon is pulled out from the ribbon supply spool and which is wound up are rotatably arranged in a cassette case. A rotary member that is inserted into the ribbon supply spool and is rotated integrally with the ribbon supply spool, and has a cylindrical protrusion at its upper end, and a rotary member that is integrally formed with the cassette case and is fitted into the ribbon supply spool from above. A spool pressing member having a cylindrical portion to be fitted and a plurality of locking grooves formed in the cylindrical portion, a coiled annular portion, and an engaging portion extending from the annular portion. A clutch spring having the annular spring part of the clutch spring is fitted to the cylindrical projection part of the rotating member, and the locking part is the spool pressing part. Ribbon cassette characterized in that, which is engaged in one of the formed locking grooves in the cylindrical portion of the. 2. The annular portion of the clutch spring is expanded when a force in the ink ribbon withdrawing direction by the ribbon take-up spool acts on the ink ribbon, and a force in a direction opposite to the ink ribbon withdrawing direction acts. The ribbon cassette according to claim 1, wherein the ribbon cassette is reduced in diameter when it is performed.