JP2538386Y2 - Ink ribbon cassette - Google Patents

Description

[Detailed description of the invention] [Industrial applications]

The present invention relates to an ink ribbon cassette used for a wire dot printer, for example.

[Prior art]

Ink ribbon cassettes are widely used in wire dot printers and the like because of their low printing cost. FIG. 6 shows an overall view of the ink ribbon cassette. In this ink ribbon cassette, a long ink ribbon 2 is stored in a case 20 in which a ribbon storage section 22, a ribbon delivery path 23, and a ribbon receiving path 24 are integrated. Ink ribbon 2
Is a non-terminal with its ends connected. Most of them are stored in the ribbon storage part 22 in the folded state,
Partly ribbon feed passage 23 and ribbon receiving passage
It goes around the case 20 through 24. A printing portion 25 exposed to the outside is provided between the ribbon sending passage 23 and the leading end of the ribbon receiving passage 24. A traveling mechanism 3 for traveling the ink ribbon 2 is arranged on the ribbon receiving passage 24 side of the ribbon storage section 22. The traveling mechanism 3 includes a driving gear 5 and a driven gear 6. The drive gear 5 and the driven gear 6 are provided with a plurality of gears separated by a fixed distance for each rotating shaft. The drive gear 5 is supported by holes provided in the bottom surface of the case 20 and a lid (not shown) of the case 20, and is connected to a rotary drive source (not shown). The driven gear 6 is rotatably supported by a gear holder 9 loosely fitted into a convex portion 21 on the side surface of the case 20, and is pressed toward the drive gear 5 by a coil spring 11 pressed against the rear surface of the gear holder 9. The drive gear 5 and the driven gear 6 mesh with the ink ribbon 2 therebetween. Separators 4a and 4b for preventing the ribbon 2 from being wound are provided on the side of the ribbon storage section 22 of the drive gear 5 and the driven gear 6. When the drive gear 5 rotates in the direction of the arrow, the driven gear 6 also rotates, and the ribbon 2 sandwiched therebetween travels clockwise, is pulled out from the ribbon storage section 22, and is fed out from the ribbon delivery path 23, the printing section 25, It is sent to the ribbon storage section 22 via the ribbon receiving passage 24 and makes a round in the case 20. The ribbon 2 sent to the ribbon storage section 22 is pushed by the succeeding ribbon 2 and moves to the ribbon delivery passage 23 side.

[Problems to be solved by the invention]

The ink ribbon cassette requires stable movement of the ribbon 2. In the case of a conventional ink ribbon cassette, the ribbon 2
When the frictional resistance (pulling power) when pulling out increases,
There is a problem that the gears 5 and 6 and the ribbon 2 slip and the running becomes unstable. This is because, when the pulling force is large, the driven gear 6 is displaced toward the spring 11 as shown by a chain line, so that the biting of the ribbon 2 is loosened and the winding force is reduced. Such a phenomenon is likely to occur when the ribbon 2 is run at high speed, when the running resistance of the ribbon 2 changes depending on the type of printing, or when the storage amount of the ribbon 2 is increased. FIG. 7 shows the relationship between the pressing force and the winding force. The figure shows an example in which the gear module (m) is 0.4 and 0.8. As described above, the pressing force of the spring 11 is increased to increase the driven gear 6 and the driving gear 5.
If the engagement is tight, a large winding force can be obtained, but if the engagement is too tight, the damage to the ribbon 2 increases and the rotational torque increases, so that a large winding force can be obtained with a small pressing force. Is required. The present invention has been made to solve the above-mentioned problem, and has as its object to provide an ink ribbon cassette having excellent running properties of the ink ribbon.

[Means for Solving the Problems]

FIGS. 1 and 2 correspond to an embodiment of an ink ribbon cassette according to the present invention made to achieve the above-mentioned object.
This will be described with reference to the drawings. As shown in FIG. 1, the ink ribbon cassette of the present invention is housed in a case 20 in which a ribbon accommodating portion 22, a ribbon sending-out passage 23 and a ribbon receiving passage 24 are integrated, and the ribbon accommodating portion 22 is mostly folded. The endless ink ribbon 2 partly loops through the inside of the case through the ribbon delivery passage 23, the printing unit 25, and the ribbon receiving passage 24, and the traveling mechanism 3 for nipping and traveling the ink ribbon 2 in the ribbon storage unit 22. And The traveling mechanism 3 has a drive gear 5 connected to a drive source (not shown) and a driven gear 6 supported by a displaceable support member 9. And a spring for pressing the driven gear 6 toward the driving gear 5 by contacting the other end with the supporting member 9.
11 are located. As shown in FIG. 2, in the ink ribbon cassette of the first invention, the distance a between the support member 9 and the stopper 7 which comes into contact when the support member 9 is displaced in the direction opposite to the pressing direction of the spring 11 is determined by sandwiching the ink ribbon 2. Thus, the distance b between the rotation center of the driven gear 6 meshed with the drive gear 5 and the rotation center of the driven gear 6 (shown by a chain line) at the limit position of engagement with the drive gear 5 is reduced. As shown in FIG. 5, in the ink ribbon cassette of the second invention, the distance between the driven gear 6 and the stopper 7 which comes into contact when the driven gear 6 is displaced in the direction opposite to the pressing force of the spring 11 is set with the ink ribbon 2 interposed therebetween. The distance between the center of rotation of the driven gear 6 meshed with the drive gear 5 and the center of rotation of the driven gear at the limit position of engagement with the drive gear 5 is set smaller.

[Action]

When the frictional resistance during running of the ink ribbon 2 increases,
As the pullout force increases, the driven gear 6 is displaced against the pressing force of the spring 11, and the distance between the driven gear 6 and the driving gear 5 is increased.
However, since the displacement of the driven gear 6 is regulated by the support member 9 and the rotating shaft 6a of the driven gear 6 abutting against the stopper 7, the driving gear 5 and the driven gear 6 always mesh with each other within the engagement limit. Even if the pressing force of the spring 11 is small, the winding force is secured.

【Example】

Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is a plan view of an embodiment of an ink ribbon cassette to which the first invention of the present invention is applied. This ink ribbon cassette has the same structure as the above-described ink ribbon cassette except for a traveling mechanism 3 for traveling the ink ribbon 2. The traveling mechanism 3 includes a driving gear 5 and a driven gear 6. The drive gear 5 and the driven gear 6 are provided with a plurality of gears separated by a fixed distance for each rotating shaft. The drive gear 5 is supported by holes provided in the bottom surface of the case 20 and a lid (not shown) of the case 20, and is connected to a rotary drive source (not shown). The driven gear 6 is rotatably supported by a gear holder 9 loosely fitted into the convex portion 21 on the side surface of the case 20, and is pressed toward the drive gear 5 by a coil spring 11 pressed against the rear surface of the gear holder 9. The driving gear 5 and the driven gear 6 mesh with each other with the ink ribbon 2 interposed therebetween.
On the 22 side, separators 4a and 4b for preventing the ribbon 2 from being entangled are provided. As shown in FIG. 2, a stopper 7 integral with the case 20 is formed on the back side of the gear holder 9, and the tip of the stopper 7 faces the back side of the gear holder 9. The distance a between the tip of the stopper 7 and the back surface of the gear holder 9 is determined by the rotation center of the driven gear 6 meshed with the drive gear 5 with the ink ribbon 2 interposed therebetween and the driven gear at the limit position where the driven gear 6 can be engaged. 6
(Indicated by a dashed line) is smaller than the distance b from the rotation center. This ink ribbon cassette operates as follows. When the drive gear 5 rotates in the direction of the arrow, the ink ribbon 2 travels clockwise, is pulled out of the ribbon storage section 22, and is sent to the ribbon storage section 22 through the ribbon delivery path 23, the printing section 25, and the ribbon receiving path 24. And goes around the case 20. The ribbon 2 sent to the ribbon storage unit 22 bends according to the direction of the preceding ribbon 2, and changes its direction when the curved tip touches the separator 4 a or 4 b, and changes its direction.
It is folded in a zigzag while pushing. The folded ribbon 2 is pushed by the succeeding ribbon, and moves to the ribbon delivery passage 23 side. When the frictional resistance during traveling of the ink ribbon 2 is large, the pull-out force increases and the driven gear 6 is displaced toward the spring 11.
The displacement is regulated by the rear surface of the gear holder 9 abutting against the stopper 7, and the drive gear 5 and the driven gear 6 mesh with each other within the engagement limit even when the drive gear 5 and the driven gear 6 are most separated from each other. Therefore, a winding force required for traveling of the ink ribbon 2 is always secured, and stable traveling of the ink ribbon 2 is maintained. FIG. 3 and FIG. 4 show another embodiment of the ink ribbon cassette of the first invention. In the ink ribbon cassette shown in FIG. 3, the opening of the convex portion 21 of the ink ribbon cassette shown in FIG. When the driven gear 6 is displaced toward the spring 11, the displacement distance is regulated by the rear surface of the gear holder 9 abutting against the stopper 7. The ink ribbon cassette shown in FIG.
Are extended along the spring 11. When the driven gear 6 is displaced toward the spring 11, the inner wall of the projection 21 acts as the stopper 7, and the displacement distance is regulated. FIG. 5 is an embodiment of an ink ribbon cassette to which the second invention of the present invention is applied. This ink ribbon cassette is driven by the driven gear 6 used in the ink ribbon cassette described above.
Is extended and loosely fitted into a long hole 26 formed in the lid 20a and the bottom surface of the case 20. When the driven gear 6 is displaced toward the spring 11, the inner surface of the elongated hole 26 acts as the stopper 7, and the displacement of the rotating shaft 6a is restricted. In the above-described embodiment, a coil spring is used as the spring 11, but a leaf spring or a ring spring may be used as the spring 11. The shape of the support member 9 and the portion 7 for regulating the displacement of the support member 9 is arbitrary. For example, a pin or a screw may be implanted inside the convex portion 21 and used as the stopper 7. The rotary shaft 6a of the driven gear 6 can be directly pressed by the spring 11 without the support member 9.

[Effect of the invention]

As described above, in the ink ribbon cassette of the present invention, the engagement of the driving gear and the driven gear is ensured, so that the ink ribbon can be reliably run. Conventionally, in order to secure this meshing, the pressing force of the driven gear against the driving gear is increased, so when there is frictional resistance during running of the ink ribbon, excessive tension is applied and the ink ribbon is cut. And other accidents. However, in the ink ribbon cassette of the present invention, the engagement is ensured even if the pressing force of the driven gear against the driving gear is small, so that the tension applied to the ink ribbon does not increase slightly even when the ribbon runs. For this reason, an accident that the ink ribbon is cut can be reliably reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of an embodiment of an ink ribbon cassette to which the present invention is applied, FIG. 2 is an enlarged view of a main part thereof, and FIGS.
The figure is a plan view of a principal part showing a ribbon storage section of another embodiment, and FIG.
FIG. 7 is a plan view of a conventional ink ribbon cassette, and FIG. 7 is a view showing a relationship between a pressing force and a winding force. 2... Ink ribbon 3... Traveling mechanism 4a and 4b... Separator 5... Drive gear 6... Followed gear 6a... Rotating shaft 7... Stopper 9. … Case 21… Protrusion, 22… Ribbon storage unit 23… Ribbon delivery passage 24… Ribbon receiving passage 25… Printing unit 26… Slot

Claims (2)

(57) [Scope of request for utility model registration] 1. A case in which a ribbon storage section, a ribbon delivery path, and a ribbon reception path are integrated, and most of the ribbon storage section is stored in a folded state, and a part of the ribbon storage section is a ribbon delivery path, a printing section, and a ribbon reception section. An endless ink ribbon that goes around the inside of the case through a passage,
An ink ribbon cassette having a traveling mechanism for nipping and running an ink ribbon in a ribbon storage section, wherein the traveling mechanism has a driving gear connected to a driving source and a driven gear supported by a displaceable support member; On the back side of the member, a spring is arranged, one end of which is engaged with the case and the other end of which is in contact with the support member and presses the driven gear toward the drive gear. The distance between the stopper and the stopper that abuts when displaced is smaller than the distance between the rotation center of the driven gear meshed with the drive gear with the ink ribbon interposed and the rotation center of the driven gear at the limit position where the driven gear can bite. An ink ribbon cassette characterized by the following. 2. A case in which a ribbon storage section, a ribbon delivery path, and a ribbon reception path are integrated, and most of the ribbon storage section is stored in a folded state in the ribbon storage section, and a part of the ribbon delivery path, the printing section, and the ribbon reception section. An endless ink ribbon that goes around the inside of the case through a passage,
An ink ribbon cassette having a traveling mechanism for nipping and running an ink ribbon in a ribbon storage section, wherein the traveling mechanism has a driving gear connected to a driving source and a driven gear supported by a displaceable support member; On the back side of the member, a spring is disposed, one end of which is engaged with the case and the other end of which is in contact with the support member and presses the driven gear toward the driving gear. The distance between the stopper and the stopper that abuts when displaced is smaller than the distance between the rotation center of the driven gear meshed with the drive gear with the ink ribbon interposed and the rotation center of the driven gear at the limit position where the driven gear can bite. An ink ribbon cassette characterized by the following.