JP2693985B2 - Method for manufacturing driven roll of ink ribbon cartridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an ink ribbon cartridge so as to face the drive roll in order to hold the ink ribbon in cooperation with the drive roll and pull the ink ribbon toward the ribbon storage portion. The present invention relates to a method for manufacturing a driven roll provided.

[Conventional technology]

As shown in FIG. 7, the ink ribbon cartridge includes a main body case (1) made of synthetic resin in which a pair of left and right ribbon guide arms (1A) and (1B) are integrally formed, and the main body case (1). And a lid (2) made of synthetic resin for closing the upper opening of the pair of arms (1).
The ink ribbon (R) stretched between (A) and (1B) can be printed by an impact dot head (not shown). The main body case (1) is formed with a left and right long ribbon storage portion (3) for storing a main portion of the ink ribbon (R) in a folded state, and an inlet side of the ribbon storage portion (3) is formed. A driving roll (4) and a driven roll (5) that cooperates as the driving roll (4) and pulls the ink ribbon (R) into the ribbon storage section (3) side in a sandwiched state, facing each other. There is. A fixed wall (7) having a ribbon passage (6) for passing the ink ribbon (R) is provided on the outlet side of the ribbon storage section (3).

Since the driven roll (5) cooperates with the drive roll (4) to hold the ink ribbon (R) and increases the holding movement force when moving the ink roll (4) as described above, Tooth-shaped irregularities are formed on the outer peripheral surface that comes into contact with each other, but the tooth-shaped irregularities are not formed on the entire outer peripheral surface, and are intermittently formed as shown in FIG. The other parts are in a reduced diameter so as not to contact the ink ribbon (R). That is, the driven roll (5) is located between a plurality of gear-shaped portions (5a) whose outer peripheral surface is brought into contact with the ink ribbon (R) and the plurality of gear-shaped portions (5a), Ink ribbon (R)
To be in contact with the gear-shaped portion (5a) so as not to come into contact with the diameter-reduced portion (5b). In this way, the reduced diameter portion (5b) is provided in a part of the driven roll (5) because the tip end protruding portion (10a) of the support member (10) that is removably attached to the main body case (1) is , By matching with the groove-shaped portion around the reduced diameter portion (5b) and gripping the reduced diameter portion (5b) with the tip protrusion (10a),
This is to achieve the support of the driven roll (5) by the support member (10). Further, when the ink ribbon (R) is pulled toward the ribbon storage portion (3), the ink ribbon (R) is forced to abut and adhere to the driven roll (5) more than necessary by the tip protruding portion (10a). To disengage,
This is to ensure that the ink ribbon (R) is drawn into the ribbon storage section (3).

In such a support structure for the driven roll (5), the tip protrusion (10a) of the support member (10) needs to have a certain strength or more. 10a) is made relatively wide, and the wide end projecting portion (10a) is used as the reduced diameter portion (5) of the driven roll (5).
Since it is arranged around b), the width of the reduced diameter portion (5b) of the driven roll (5) is often set longer than that of the gear-shaped portion (5a).

As the driven roll (5), a solid one is generally used, but when it is necessary to take measures such as weight reduction, a through hole (5c) extending in the axial direction is used. It is also used that is provided in the center.

The driven roll (5) having a complicated shape as described above is
Generally, it is often manufactured by injection molding. When the driven roll (5) is manufactured by injection molding, in the mold opening process, which is one process of manufacturing the driven roll (5), at least part corresponding to the reduced diameter portion of the mold is divided type and moved in the mutually separating direction. Need to let. Because
If the part corresponding to the reduced diameter part of the mold is kept in the same position after forming, the reduced part of the molded product and the corresponding part of the reduced part of the mold are entangled and the molded product is projected using a member. This is because it cannot project in the axial direction. on the other hand,
The parts corresponding to the gear-shaped parts of the forming die are split dies and cannot be simply moved in the direction away from each other. This is because the gear-like portion (5a) has tooth-like irregularities formed on its outer peripheral surface, and therefore a part of the tooth-like irregularities (specifically, protruding and retracting in a direction intersecting the moving direction of the split mold). This is because the concaves and convexes to be inserted engage with the split mold when moving the split mold, and hinder the smooth movement of the split mold.

Therefore, conventionally, as shown in FIGS. 9 (a), 9 (b), and 9 (c), a portion of the mold (21) corresponding to the periphery of the space for forming the molded product (51) is formed into a gear shape. The corresponding parts of the parts are fixed molds (21a), and the corresponding parts of the reduced diameter parts are divided into movable molds (21b) which are movable in the direction of separation from each other. After the molding shown in FIG. As shown in (b), the movable die (21b) is moved in a direction away from each other to move the movable die (21b).
And the molded product (51) are released from each other, and then the molded product (51) is ejected using the projecting member (22) as shown in FIG. 51)
Was taken out of the mold (21). Before ejecting the molded product (51), cover (21) of the molding die (21).
It goes without saying that c) should be removed in advance.

[Problems to be solved by the invention]

When the molded product (51) is taken out of the molding die (21) by such a method, the width dimension of the reduced diameter portion (5b) of the driven roll (5) to be manufactured is smaller than that of the gear-shaped portion (5a). 9 is also short as shown in FIG. 9, in the process of ejecting the molded product (51) using the protrusion member (22), the gear-like portion (51
Since (a) always engages with any one of the tooth-shaped concave-convex molding surfaces of the fixed mold (21a) (these all have the same circumferential phase), the molded product (51) is The molded product (51) is projected without rotating in the direction, and the tooth-like irregularities on the outer peripheral surface of the gear-like part (51a) do not interfere with the tooth-like irregularities on the inner peripheral surface of the fixed die (21a). It will be ejected smoothly.

However, when the width dimension of the reduced diameter portion (5b) of the driven roll (5) to be manufactured is longer than that of the gear-shaped portion (5a) as shown in FIG. 10, the protruding member (22) is used. In the process of ejecting the molded product (51), the gear-like portion (51a) can be in a released state without engaging with any of the tooth-shaped concave-convex molding surfaces of the fixed die (21a). As a result of the molded article (51) being able to rotate in the circumferential direction, tooth-shaped irregularities on the outer peripheral surface of the gear-shaped part (51a) of the molded article (51) and tooth-shaped irregularities on the inner peripheral surface of the fixed die (21a). And the phase in the circumferential direction do not match, and the above-mentioned tooth-shaped irregularities interfere with each other, making it impossible to project the molded product (51) or the molded product (51).
There is a problem in that the gear-shaped portion (51a) of (1) has a flaw.

The present invention has been made in view of such circumstances,
It is an object to provide means capable of solving the above-mentioned problem.

[Means for solving the problem]

A method for manufacturing a driven roll of an ink ribbon cartridge according to the present invention is such that an outer peripheral surface of the ink ribbon is brought into contact with the ink ribbon in order to hold the ink ribbon in cooperation with a drive roll and pull the ink ribbon toward the ribbon storage portion. A plurality of gear-shaped portions that are located between the gear-shaped portions and have a diameter that is smaller than that of the gear-shaped portions so as not to contact the ink ribbon. After molding a driven roll composed of a combination with a reduced-diameter portion set to be longer, in a molding die of an injection molding device, the compression of the molding die is taken out to take out the molded product from the molding die. After the part corresponding to the diameter part is locally expanded in diameter to open the mold, the projecting member movable in the axial direction of the forming mold is moved to press the end surface of the formed product and press the end face. Stick out of the mold In the method of manufacturing, in the injection molding device, there is provided rotation preventing means for preventing rotation of the molded product in a circumferential direction in a process in which the molded product is projected by a projecting member. It is characterized in that it is provided in advance on a surface other than the surface, and the rotation preventing means is used to prevent the rotation of the molded product in the circumferential direction while the molded product is projected out of the molding die.

[Action]

When the driven roll of the ink ribbon cartridge is manufactured by using the method of the present invention, the molded product is formed in the mold of the injection molding apparatus and then ejected outside the mold, Even if it is not guided by the molding surface of the molding die by the movement preventing means, its rotation in the circumferential direction is prevented, and the molding die is projected out of the molding die in the rotation prevention state.

〔The invention's effect〕

Therefore, in the process of ejecting the molded product out of the molding die, the circumferential phase of the tooth-shaped irregularities on the outer peripheral surface of the gear-shaped portion of the molded product and the tooth-shaped irregularities on the inner peripheral surface of the fixed die always match. As a result, the above-mentioned tooth-like irregularities do not interfere with each other, and the problem that the molded product cannot be projected or that the gear-shaped portion of the molded product is flawed does not occur. As a result, even if the driven roll to be manufactured has a complicated shape as described above, it is possible to reliably manufacture the driven roll without scratching the gear-shaped portion thereof.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 and 2, the driven roll (5) to be manufactured has three gear-shaped portions (5a) whose outer peripheral surface is brought into contact with the ink ribbon, and the three gear-shaped portions. It is located at two places in the middle of (5a) and has a diameter smaller than that of the gear-like portion (5a) so as not to contact the ink ribbon, and the width dimension is set longer than that of the gear-like portion (5a). It consists of a combination with the reduced diameter part (5b). Further, the driven roll (5) is provided with a through hole (5c) extending in the axial direction at the central portion in order to reduce its weight and the like, but in the present embodiment, the rotation according to the method of the present invention is performed. The hole shape is set to be D-shaped so that the blocking means (A) can be applied.

3 (a) and 3 (b) show the main steps of manufacturing the driven roll (5) by injection molding.
As shown in the figure, the molding die (21) of the apparatus used for performing the injection molding includes the fixed die (21a) and the movable die (21b) similar to those described with reference to FIGS. The mandrel (23), which is a rod-shaped body having a D-shaped cross section, is disposed in the molding die (21) to form a hole circumferential surface of the through hole (5c) during molding. (23) serves as the rotation preventing means (A). Then, the mandrel (23) can be inserted through the central portion of the protruding member (22) used for protruding the molded product (51) molded by the molding mold (21) to the outside of the molding mold (21). A through hole (22a) is provided.

After the molded product (51) of the driven roll (5) having the above-mentioned shape is molded using the molding mold (21), it is molded into the molding mold (2
1) When projecting to the outside, move the movable die (21b) in the direction away from each other as shown in FIG.
b) and the molded product (51) are released from the engaged state, and then the molded product (51) is ejected using the projecting member (22) as shown in FIG. Articles (51)
The molded product (51) is taken out of the molding die (21) by the mandrel (23) as the rotation preventing means (A) in the projecting process.
Even if it is not guided by the molding surface, its rotation in the circumferential direction is blocked, and it is projected to the outside of the molding die (21) in the rotation blocked state.

In the above embodiment, the mandrel (2
Although the cross-sectional shape of 3) is set to be D-shaped, the shape may be a non-circular shape, and various examples such as a triangle, a quadrangle, and an ellipse can be considered.

Further, the molded product (51) will be provided with a through hole (5c) having a non-circular cross section. If the through hole (5c) needs to have a circular cross section, for example, Boring may be performed on the molded product (51) after injection molding.

(Another embodiment)

When the driven roll (5) to be manufactured is solid as shown in FIGS. 4 and 5, the method of the present invention as described below can be considered.

That is, in the injection-molded product (51) of the driven roll (5), the molded product (51) is pushed by the projecting member (22) to the surface to be in contact with the projecting member (22). Occasionally, an engaging portion (5d) for engaging both the molded product (51) and the protruding member (22) without sliding in the circumferential direction is provided as the rotation preventing means (A) according to the present invention. As a specific example of the engaging portion (5d), a protrusion having a D-shaped recess is formed on the surface of the molded product (51) to be in contact with the protruding member (22). Can be considered. The engaging portion (5d) can be easily formed by forming the end surface of the protruding member (22), which is a part of the molding surface during injection molding, into a shape matching the protruding portion.

FIGS. 6 (a) and 6 (b) show the main steps of obtaining the injection-molded product (51) of the driven roll (5) described above, but as shown in the figure, the molding of the apparatus used for injection molding is performed. Type (2
1) includes a fixed mold (21a) and a movable mold (21b) similar to those described in FIGS. 9 and 10. After the injection molding, the movable die (21b) is moved in the direction away from each other as shown in FIG. 6 (a) so that the movable die (21b) and the molded product (5
The molded product (51) is taken out of the molding die (21) by using the projecting member (22) after releasing the state in which it is engaged with 1). In the projecting process, the molded product is removed. The rotation preventing means (51) is prevented from rotating in the circumferential direction by the engaging portion (5d) serving as the rotation preventing means (A) even if it is not guided by the molding surface of the molding die (21). It will be ejected outside the molding die (21) in the blocked state.

In the above-mentioned embodiment, the engaging portion (5d) has a D-shaped recess formed in the protrusion, but the recess may have a non-circular shape, such as a triangle or a quadrangle. Various embodiments such as an elliptical shape are possible.

In addition, a protrusion functioning as an engaging portion (5d) is provided on one end surface of the molded product (51), but when it is better that the protrusion (4d) does not finally exist, For example, this may be removed by cutting after injection molding.

In each of the above-described examples, the manufactured driven roll (5) was provided with three gear-shaped portions (5a), but two or more gear-shaped portions (5a) were provided. It goes without saying that the method of the present invention can be applied even if it is one.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the method shown in the accompanying drawings by the entry.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of a driven roll manufactured by the method of the present invention, FIG. 2 is a bottom view thereof, and FIGS. 3 (a) and 3 (b) show the driven roll manufactured by the method of the present invention. FIG. 4 is a longitudinal sectional view showing another example of the driven roll manufactured by the method of the present invention, FIG. 5 is a bottom view thereof, and FIGS. 6 (a) and 6 (b) are FIG. 7 is an explanatory view showing a main process of manufacturing the driven roll by the method of the present invention, FIG. 7 is a cross-sectional view of an ink ribbon cartridge in which the driven roll is mounted, and FIG. 8 is a mounting portion of the driven roll. The exploded perspective view, FIGS. 9 (a), 9 (b), 9 (c), and 10 are explanatory views showing the main steps of the conventional driven roll manufacturing method. (3) ...... Ribbon storage part, (4) ...... Drive roll,
(5) …… Driven roll, (5a) …… Gear-shaped part, (5b)…
… Reduced diameter part, (5c) …… Through hole, (5d) …… Engagement part, (2
1) ... Mold, (22) ... Projecting member, (23) ... Mandrel, (51) ... Molded product, (A) ... Rotation preventing means, (R) ... Ink ribbon.

Claims (3)

(57) [Claims] 1. An outer circumference of the ink ribbon (R) for pulling the ink ribbon (R) toward the ribbon storage section (3) while holding the ink ribbon (R) in cooperation with a drive roll (4). A plurality of gear-like portions (5a) whose surfaces are brought into contact with each other, and the gear-like portions (5a) which are positioned in the middle of the plurality of gear-like portions (5a) so as not to come into contact with the ink ribbon (R). ), And a driven roll (5) composed of a reduced diameter portion (5b) whose width dimension is set to be longer than that of the gear-shaped portion (5a). After molding in the mold (21), a portion corresponding to the reduced diameter portion (5b) of the molding die (21) is locally localized so that the molded product (51) can be taken out from the molding die (21). After expanding the diameter and opening the mold, the mold (2
(1) A method of manufacturing by ejecting the end surface of the molded product (51) by moving an axially movable protruding member (22) and projecting the end surface of the molded product (51) out of the molding die (21). Further, a rotation preventing means (A) for preventing rotation of the molded product (51) in the circumferential direction while the molded product (51) is projected by the projecting member (22) is provided in the molding die (21). ) Is provided in advance on a surface other than the tooth-shaped irregularity molding surface, and the rotation preventing means (A) is used to prevent the molding (51) from rotating in the circumferential direction. A method for manufacturing a driven roll of an ink ribbon cartridge, which comprises protruding the molding die (21) to the outside. 2. A method of manufacturing a driven roll of an ink ribbon cartridge, the method of manufacturing a driven roll (5) having a through hole (5c) extending in the axial direction, wherein the rotation preventing means (A) is A mandrel (23), which is arranged in the molding die (21) to form a hole peripheral surface of the through hole (5c) at the time of injection molding and is made of a rod-shaped body having a non-circular cross section, Even when the molded product (51) is projected by the projecting member (22) while the inner peripheral surface of the molded product (51) is guided by the (23), the molded product (51) is also projected. The method for producing a driven roll of an ink ribbon cartridge according to claim 1, wherein the molded product (51) is prevented from rotating in the circumferential direction. 3. A method for manufacturing a driven roll of an ink ribbon cartridge, wherein a solid driven roll (5) is manufactured, wherein the rotation preventing means (A) comprises a protrusion member (22) and the molded product. An engaging portion (5b) provided for engaging with the abutting portion where (51) abuts each other without slipping the both in the circumferential direction, and the engaging portion (5d) is interposed. By projecting the molded product (51) into the projecting member (22) while engaging the both, the rotational movement of the molded product (51) in the circumferential direction even in the process of projecting the molded product (51). 2. The method for manufacturing a driven roll of an ink ribbon cartridge according to claim 1, wherein