JPH08133603A - Spool for print media - Google Patents

Abstract

PURPOSE: To provide a spool for print media having high quality and high productivity at a low cost. CONSTITUTION: A cylindrical spool body 2, both flange parts 2a, 2b of which form a ribbon winding shaft part 2c between themselves, and a cylindrical, small-diameter cap part 3 which is positioned on the side of the flange part 2a of the spool body 2 and, the tip 3a of which is closed, are integrally formed by injection molding to form a spool 1 for print media of a single part. Further, a circular through hole 2d is formed at a position less than 10mm apart from the flange part 2a of the spool body 2. Thus, the wall thicknesses of the spool body 2 and the cap part 3 can be constantly formed evenly over the full circumference at the time of injection molding, and productivity can also be further improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print medium spool used as a ribbon supply spool, a ribbon winding spool, or the like of a print ribbon cartridge.

[0002]

2. Description of the Related Art For example, a ribbon cartridge used in a color printer or the like uses a ribbon supply spool and a ribbon winding spool as spools for print media around which a sublimation transfer type ink ribbon or the like is wound. This will be specifically described with reference to FIGS. 4 and 6.
In FIG. 6, reference numeral 1 is a spool for print media.
For example, it is used as a ribbon supply spool or a ribbon winding spool of a ribbon cartridge 10 for performing color printing on A4 size printing paper shown in FIG. This print media spool 1 has a fan-radius portion 2 at both ends.
For example, a cylindrical spool body 2 made of synthetic resin, which is a ribbon winding shaft portion 2c of the sublimation transfer type ink ribbon 11 between a and 2b, is press-fitted to the side of the funnel portion 2a as one end portion of the spool body 2. The cap portion 3 is made of a synthetic resin and has a two-step cylindrical shape and a small diameter, the end portion 3a side of which is fitted with.

This conventional spool 1 for print media
As shown in FIG. 4, the spool body 2 and the cap portion 3 are
Since it was composed of two parts, there were the following problems.

(1) Since each of the injection molding dies for molding the parts is required, the equipment investment increases.

(2) Since the cap portion 3 is press-fitted into the spool body 2, extra work man-hours are required, and the cost is increased accordingly.

(3) Since the cap portion 3 is press-fitted into the spool body 2, the dimensions of each component change due to variations in molding conditions during injection molding, and the cap portion 3 does not fit tightly into the spool body 2. Sometimes it is too loose and on the contrary, it is very difficult to control.

Therefore, as shown in FIG. 5, a technique has been proposed in which the spool main body 2 and the cap portion 3 are integrally molded with one injection molding die 100.

[0008]

However, the spool body 2 is formed by one injection molding die 100 shown in FIG.
If the cap and the cap 3 are integrally molded, the molded product is A4
Since the size is long, the tip 104a side of the inner diameter pin 104, which is arranged in the cavity 103 composed of the fixed mold 101 and the movable mold 102 and forms the inner peripheral surface of the spool body 2, is the gate 105 side. The resin was bent toward the fixed mold 101 side due to the injection pressure of the resin, and the thickness of the molded product was uneven between the thick portion A and the thin portion B, which was not preferable in terms of quality.

Therefore, the present invention provides a high-quality and highly productive spool for print media, which can make the wall thickness uniform over the whole at low cost.

[0010]

[Means for Solving the Problems] A cylindrical spool body having a ribbon winding shaft portion between both end portions is provided, and a closed cylindrical small-diameter cap portion is provided on one end side of the spool body. In the spool for print media having the above, the spool body and the cap portion are integrally formed by injection molding, and a through hole is formed on one end side of the spool body.

[0011]

Since the spool body and the cap portion are integrally structured, only one injection molding die is required, and the capital investment is suppressed. Further, even if there is some variation in molding during injection molding, the work of assembling the parts is not required, so the cost can be further reduced. Furthermore, since the through hole is formed on the one end side of the spool body, the thicknesses of the spool body and the cap portion are always uniform throughout.

[0012]

Embodiments of the present invention will be described in detail below with reference to the drawings. The same parts as those of the conventional structure will be described with the same reference numerals. The ribbon cartridge 10 shown in FIG. 6 is also incorporated.

In FIG. 1, reference numeral 1 is a spool for print media, which is used as a ribbon supply spool or a ribbon take-up spool of a ribbon cartridge 10 for color printing on, for example, A4 size printing paper shown in FIG. Is.

The print medium spool 1 is made of a synthetic resin and has a cylindrical spool body 2 in which, for example, a ribbon winding shaft portion 2c of the sublimation transfer type ink ribbon 11 is provided between the end portions 2a and 2b. , The tip 3 which is located on the side of the funnel portion 2a as one end of the spool body 2
It is configured by integrally molding a cylindrical small-diameter cap portion 3 made of synthetic resin, the a side of which is closed, by injection molding.

From the fan-radius portion 2a of the spool main body 10
Round through-holes (a pair of notched holes that penetrated) 2d, 2d are formed at positions within mm. Further, a cylindrical rotary shaft portion 2 having a diameter larger than that of the ribbon winding shaft portion 2c is provided outside the funnel portion 2b as the other end portion of the spool body 2.
e is integrally formed. On the inner peripheral surface of the rotary shaft portion 2e, a plurality of ribs 2f for locking the driving of the printer are integrally formed in parallel with each other. The rotation shaft portion 2e of the spool body 2 and the tip 3a of the cap portion 3 serve as the center of rotation of each spool 1 in the ribbon cartridge 10.

FIG. 2 shows a state where the print medium spool 1 having the above-mentioned structure is injection-molded by the injection molding die 100. Inner diameter pin 104 of this injection molding die 100
A pair of slide pins 106, 106 for fixing the inner diameter pin are provided on the fixed mold 101 and the movable mold 102 at positions near the distal end portion 104a so as to be vertically slidable. The inner diameter pin 10 disposed in the cavity 103 between the tips of the pair of slide pins 106, 106.
One end side (the tip end 104a side) of the large diameter portion 4 can be fixed so as to be sandwiched from above and below,
At the time of injection molding, unlike the prior art, the tip 104a side of the inner diameter pin 104 is prevented from bending toward the fixed mold 101 side due to the injection pressure of the resin of the gate 105.
As a result, the gap between the cavity 103 and the outer peripheral surface of the inner diameter pin 104 is always uniform throughout.

Further, a pair of slide pins 106, 10
The position of 6 is from the run-radius portion 2a of the spool body 2 to 10
It is set to come within a mm position. The position of the pair of slide pins 106, 106 may be set to a position facing the tubular portion of the cap portion 3, but since the cap portion 3 has a smaller diameter than the spool body 2, each slide pin 10 is provided.
It is necessary to reduce the diameter of 6 dimensionally, and the durability of the pin itself may be weakened. Therefore, in order to improve the durability of the pin itself, it is necessary to position each slide pin 106 on the spool body 2 side where the diameter of the pin itself can be set larger, but there is a hole in the ribbon winding shaft portion 2c. Since it is a place where there is no problem in terms of quality, it is best to position the pair of slide pins 106 so that they are located within 10 mm from the funnel portion 2a of the spool body 2. That is, even if the through holes 2d, 2d come within 10 mm from the funnel portion 2a of the spool body 2, the positions of the through holes 2d, 2d are the same.
Since it is located in an area other than the effective coloring use area such as 0 (yellow), magenta (M), and cyan (C), there is no problem in color printing. In addition, the pair of slide pins 106, 106 are provided in the respective molds 101, 102 after injection molding.
Since it slides in the outward direction, it has a structure that does not hinder the removal of the molded product.

According to the print medium spool 1 of the above embodiment, the print medium spool 1 is formed of a single point by integrally forming the spool body 2 and the cap portion 3 by injection molding. Mold 10
Only one unit is required, and capital investment can be suppressed. Further, since there is no need for the conventional assembly work of parts even when there is some molding variation at the time of injection molding of the print media spool 1 by the injection molding die 100, it is possible to reduce the number of work steps and reduce the cost. It can be further improved. Further, the funnel portion 2a of the spool body 2
Since the through holes (a pair of notched holes penetrating in a straight line) 2d, 2d are formed at a position within 10 mm, the thicknesses of the spool body 2 and the cap portion 3 are always uniform over the entire circumference thereof. can do. This makes it possible to further improve the productivity (formability, assembling property) of the print media spool 1 and provide a high quality print media spool 1 at low cost.

FIG. 3 shows a spool 1'for print media according to another embodiment. The print media spool 1 ′ has a fan-shaped portion 2 a as one end of the spool body 2.
This is different from the embodiment shown in FIG. 1 in that rectangular through holes (a pair of cutout holes that penetrate) 2d ', 2d' are formed at a position within 10 mm from. As a result, the same operation and effect as those of the embodiment shown in FIG. 1 are achieved.

Although the through hole is formed on the one end side of the spool body according to each of the above embodiments, the through hole may be formed on the cylinder side of the cap part. Also, I explained the long print media spool for A4 size.
Needless to say, each of the above-described embodiments can be applied to spools for short print media such as 5 sizes or postcards.

[0021]

As described above, according to the present invention, the spool for the print medium is integrally formed by injection molding the spool main body and the cap portion, so that the spool for print media is composed of one-point component. Only one unit is required, and capital investment can be suppressed. In addition, since there is no need to assemble parts even if there is some molding variation during injection molding, the number of work steps can be reduced and the cost can be further reduced. Further, since the through hole is formed on the one end side of the spool body, the thickness of the spool body and the cap portion can be made uniform throughout the entire time, and the productivity and quality can be further improved. You can

[Brief description of drawings]

FIG. 1 is an explanatory view showing a central portion of a long print medium spool according to an embodiment of the present invention in a cutaway manner.

FIG. 2 is a cross-sectional view showing a state of injection molding of the print media spool.

FIG. 3 is an explanatory view showing a central portion of a long print medium spool of another embodiment in a broken manner.

FIG. 4 is an explanatory view showing a central portion of a conventional long print medium spool in a broken manner.

FIG. 5 is a cross-sectional view showing a state of another conventional example of a long print medium spool in which injection molding is performed by improving the drawbacks of the conventional print medium spool.

FIG. 6 is a perspective view of a ribbon cartridge that uses a spool for print media.

[Explanation of Codes] 1, 1 '... Print media spool 2 ... Spool bodies 2a, 2b ... Funradius portions (both ends) 2c ... Ribbon winding shaft portion 2d, 2d' ... Through hole 3 ... Cap portion

Claims (2)

[Claims] 1. A print having a cylindrical spool body having a ribbon winding shaft portion between both ends thereof, and a closed cylindrical small-diameter cap portion on one end side of the spool body. In a spool for media, a spool for print media, characterized in that the spool body and the cap portion are integrally formed by injection molding, and a through hole is formed on one end side of the spool body. 2. The spool for print media according to claim 1, wherein the through hole is provided at a position within 10 mm from one end of the spool body.