JP3407433B2 - Print media spool - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print medium spool used as a ribbon supply spool or a ribbon take-up spool of a print ribbon cartridge. 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 take-up spool as a print media spool on which a sublimation transfer type ink ribbon or the like is wound. I have. This will be specifically described with reference to FIGS.
Reference numeral 1 in the figure denotes a print media spool, and FIG.
Are used as a ribbon supply spool and a ribbon take-up spool of the ribbon cartridge 10 for performing color printing on, for example, A4 size photographic paper. This print media spool 1 has flanges 2 at both ends.
For example, a cylindrical spool body 2 made of a synthetic resin and having a portion between a and 2b serving as a ribbon winding shaft 2c of the sublimation transfer ink ribbon 11 and a funnel 2a as one end of the spool body 2 is press-fitted. The cap 3 has a two-stage cylindrical small-diameter cap portion 3 made of synthetic resin and closed at the tip 3a side. [0003] This conventional print media spool 1
As shown in FIG. 4, the spool body 2 and the cap 3
However, there are the following problems due to the use of the above two components. (1) Injection molding dies for molding parts are required, and equipment investment is increased. (2) Since the cap portion 3 is press-fitted into the spool body 2, extra work steps are required, and the cost increases accordingly. (3) Since the cap section 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 section 3 does not fit tightly into the spool body 2. In some cases, or on the contrary, it is too loose, and the control is very difficult. Therefore, as shown in FIG. 5, a technique has been proposed in which the spool body 2 and the cap portion 3 are integrally formed by one injection molding die 100. [0008] However, the spool body 2 is provided by one injection molding die 100 shown in FIG.
And the cap part 3 are integrally molded, the molded product is A4
Since it is long for size, the distal end 104 a of the inner diameter pin 104 which is arranged in the cavity 103 formed by the fixed mold 101 and the movable mold 102 and forms the inner peripheral surface of the spool body 2 is on the gate 105 side The molded product was bent toward the fixed mold 101 side by losing the injection pressure of the resin, and the thickness of the molded product was uneven in the thick portion A and the thin portion B, which was not preferable in quality. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a spool for a print medium of high quality and high productivity which can make the wall thickness uniform over the whole at low cost. [0010] The present invention has a cylindrical spool body having a ribbon winding shaft portion between both ends, and a closed cylindrical small-diameter tube at one end side of the spool body. In the print medium spool having the cap portion, the spool body and the cap portion are integrally formed by injection molding, and a through hole is provided at a position within 10 mm from one end of the spool body. Since the spool body and the cap portion are of an integral structure, only one injection molding die is required, which reduces capital investment. In addition, even if there is some variation in molding at the time of injection molding, assembling work of parts is unnecessary, so that the cost can be further reduced. Further, since the through hole is formed at one end of the spool main body, the thickness of the spool main body and the cap portion is always uniform throughout. Embodiments of the present invention will be described below in detail with reference to the drawings. The same parts as those of the conventional configuration are denoted by the same reference numerals and described. The ribbon cartridge 10 shown in FIG. 6 is used. In FIG. 1, reference numeral 1 denotes a print medium spool which is used as a ribbon supply spool or a ribbon take-up spool of a ribbon cartridge 10 shown in FIG. 6 for performing color printing on, for example, A4 size photographic paper. It is. The spool 1 for a print medium is made of a synthetic resin and has a cylindrical spool body 2 having, for example, a ribbon winding shaft portion 2c of a sublimation transfer type ink ribbon 11 between the end portions 2a and 2b at both ends. The tip 3 is located on the side of the funnel 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 with the a side closed, by injection molding. [0015] 10 minutes from the funnel 2a of the spool body 2
At positions within mm, round through holes (a pair of notched holes penetrating) 2d, 2d are formed. Further, a cylindrical rotary shaft 2 having a larger diameter than the ribbon winding shaft 2c is provided outside the funnel 2b as the other end of the spool body 2.
e is integrally formed. A plurality of printer drive locking ribs 2f are integrally formed on the inner peripheral surface of the rotating shaft portion 2e in parallel to each other. The rotation shaft 2 e of the spool body 2 and the tip 3 a of the cap 3 are the center of rotation of each spool 1 in the ribbon cartridge 10. FIG. 2 shows a state in which the print medium spool 1 having the above-described structure is injection-molded by an injection mold 100. Inner diameter pin 104 of this injection molding die 100
A pair of slide pins 106, 106 for fixing the inner diameter pins are slidably provided in the fixed mold 101 and the movable mold 102 at positions closer to the distal end portion 104a. The inner diameter pin 10 disposed in the cavity 103 between the respective tips of the pair of slide pins 106, 106
4, one end of the large diameter portion (the end 104a side) can be fixed so as to be clamped from above and below.
At the time of injection molding, unlike the related art, the distal end portion 104a of the inner diameter pin 104 is prevented from bending toward the fixed mold 101 due to the injection pressure of the resin of the gate 105.
Thereby, 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 10 to 10 mm from the funnel 2 a of the spool body 2.
mm. The position of the pair of slide pins 106 may be set at a position facing the cylindrical portion of the cap portion 3. However, since the cap portion 3 has a smaller diameter than the spool body 2, each slide pin 10
The diameter of the pin 6 needs to be reduced in size, and the durability of the pin itself may be weakened. Therefore, in order to increase 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. However, there is a hole in the ribbon winding shaft 2c. It is best to position the pair of slide pins 106 so as to be located within 10 mm from the funnel 2a of the spool body 2 because the quality does not matter. That is, even if the through holes 2d and 2d come within a position of 10 mm or less from the funnel 2a of the spool body 2, the positions of the through holes 2d and 2d
Since it is located in an area other than the effective coloring use area such as 0 (yellow (Y), magenta (M), and cyan (C)), there is no problem in color printing. In addition, the pair of slide pins 106, 106 are used for the respective molds 101, 102 after the injection molding.
, So that there is no problem in taking out the molded product. According to the print medium spool 1 of the embodiment described above, the print medium spool 1 is formed as a single point component by integrally forming the spool body 2 and the cap portion 3 by injection molding. Mold 10
0 is sufficient for one unit, and equipment investment can be suppressed. Also, even if there is some variation in the molding when the print medium spool 1 is injection-molded by the injection molding die 100, the assembly work of the conventional parts is unnecessary, so that the number of work steps can be reduced and the cost can be reduced. This can be achieved even more. Furthermore, the funnel 2a of the spool body 2
Since the through holes (a pair of cut-out holes penetrating in a straight line) 2d, 2d are formed at positions within 10 mm from each other, the thickness of the spool body 2 and the cap portion 3 is always made uniform over their entire circumference. can do. Thereby, the productivity (moldability and assemblability) of the print media spool 1 can be further improved, and a high-quality print media spool 1 can be provided at low cost. FIG. 3 shows a spool 1 'for a print medium according to another embodiment. This print media spool 1 ′ has a funnel 2 a as one end of the spool body 2.
This embodiment differs from the embodiment shown in FIG. 1 in that rectangular through-holes (a pair of cut-out holes penetrating) 2d 'and 2d' are formed at positions within 10 mm from the center. Thus, the same operation and effect as those of the embodiment shown in FIG. 1 are obtained. According to each of the above embodiments, the through hole is formed at one end of the spool main body. However, a through hole may be formed at the cylindrical portion of the cap. Also, a description has been given of a long print media spool for A4 size.
Needless to say, each of the above embodiments can be applied to a spool for a short print medium such as a five-size one or a postcard. As described above, according to the present invention, the spool for the print medium is constituted by a single-point part by integrally molding the spool body and the cap portion by injection molding. Only one die is required, and capital investment can be suppressed. Further, even if there is some variation in molding during injection molding, assembling work of parts is unnecessary, so that the number of working steps can be reduced and cost can be further reduced. Further, since the through hole is formed at one end of the spool main body, the thickness of the spool main body and the cap portion can always be made uniform over the entirety, thereby further improving the productivity and quality. Can be.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of a long print media spool according to an embodiment of the present invention, in which a center portion of the spool is cut away. FIG. 2 is a cross-sectional view showing a state of injection molding of the print medium spool. FIG. 3 is an explanatory view showing a central portion of a long print medium spool of another embodiment, which is cut away. FIG. 4 is an explanatory view showing a central portion of a conventional long print medium spool in a cutaway manner. FIG. 5 is a cross-sectional view showing the state of injection molding of another conventional long print medium spool in which the drawbacks of the conventional print medium spool are improved. FIG. 6 is a perspective view of a ribbon cartridge using a print medium spool. [Description of Signs] 1, 1 '... Spool for print media 2 ... Spool main body 2a, 2b ... Funraji part (both ends) 2c ... Ribbon winding shaft part 2d, 2d' ... Through hole 3 ... Cap part

────────────────────────────────────────────────── (5) References JP-A-6-64847 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B65H 75/14 B41J 17/24 B65H 75 / 18

Claims (1)

(57) [Claim 1] A cylindrical spool body having a ribbon winding shaft between both ends and a closed cylindrical shape at one end of the spool body. In a print media spool having a small diameter cap portion, the spool body and the cap portion are integrally formed by injection molding, and 10 mm from one end of the spool body.
A spool for print media, characterized in that a through hole is provided within the position .