JP2924235B2 - Rubber sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber sheet for a printer, in which printing characters are arranged and manufactured by injection molding or the like.

[0002]

2. Description of the Related Art Conventionally, a rubber sheet for a printer formed by injection molding or the like is integrally formed of a spool 1, a fan-shaped gate 2 and a rubber sheet 3 as shown in FIGS. And cut from the cut surface 4 between the rubber sheets 3 before use.

[0003]

However, since the conventional rubber sheet is thin, it is difficult to cut it with a blade or a jig, and the dimensional accuracy varies greatly. Also, when assembling with other parts, the sheet end is rounded. Had problems such as In order to solve the conventional problems, the present invention enables cutting without using a blade, a jig, and the like.
It is an object of the present invention to obtain a rubber sheet that has no variation in dimensional accuracy, does not have a rounded end face, and is easy to set on other parts.

[0004]

SUMMARY OF THE INVENTION The present invention relates to a rubber sheet for a printer which is manufactured by injection molding and has a film gate formed at a gate of a molding die. 1) A thick portion thicker than the thickness of the film gate is formed on the rubber sheet side and the runner side of the film gate to face each other. (2) A through hole in the thickness direction is provided in the film gate. The length of the film gate between them is 1 mm or less.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings. 1 and 2, the rubber sheet 3 is manufactured by injection molding. The material flows from the spool 1, passes through the fan gate 2 and the film gate 5, and is filled in the rubber sheet 3. Any material can be used as long as it has rubber elasticity such as silicone rubber, fluorine rubber and elastomer and can be injection molded.However, liquid silicone rubber is preferred because it has good fluidity and moldability and is low in cost. Are suitable.

On both sides of the film gate 5, runners
For each of the fan-shaped gate 2 side and the rubber sheet 3 side
Ribs 6 and 7 which are thick portions are provided, and are cut by hand or the like from the cut surface 4 after molding. Since the film gate 5 is cut by hand or the like, the ribs 6 and 7
Should be formed sufficiently thin with respect to
mm or more and 0.5 mm or less is desirable. Film gate 5
If the thickness is 0.1 mm or less, the filling of the material is inferior,
If it is 0.5 mm or more, cutting becomes difficult. The thickness of the ribs 6 and 7 needs to be at least twice as large as the thickness of the film gate 5, and below this, the cut surface 4 is not constant.
Although there is no limitation in the thickness direction, a thickness of 10 mm or less is suitable for practical use. The length of the film gate 5 depends on the required accuracy of the cut surface, but is preferably 1 mm or less.

If a small through hole 8 is provided in a part of the film gate 5, the film gate 5 is cut by using the hole as a trigger, so that it can be cut more easily and the quality of the cut surface 4 is stabilized. The location of this minute through hole 8 may be anywhere within the range of the film gate 5, and is provided at the center of the film gate 5 in the example of FIG. 2, and in FIG. 5, which is another embodiment of the present invention, of the film gate 5. It is provided at the end. At least one micro through hole 8 is required, and at most three is appropriate. Further, the size of the minute through hole 8 is at least 0.3 m when the maximum diameter of the hole is equal to or less than the length of the film gate 5.
m is sufficient, and the shape may be a round hole, an elliptical hole, or a square hole. The example of FIG. 2 is a round hole, and the example of FIG. 5 is a square hole.

As described above, the present invention requires the use of a cutter or the like, whereas the present invention provides a method of cutting the rubber sheet 3 between the rubber sheet 3 and the fan-shaped gate 2 by hand or the like.
No cuts, cracks, etc. are generated, and the cut surface 4 can be obtained with higher dimensional accuracy than a conventional method using a cutter.

Further, in the conventional rubber sheet 3, after molding, it is put into a storage container, cut at another place by a cutter or the like, and then returned to the storage container. However, according to the present invention, not only the process is simplified, but also the process of simplifying the process and cutting off dust and the like is eliminated according to the present invention. The cleaning process can be eliminated, and quality can be improved and costs can be reduced.

Further, in the conventional molding, since the thickness of the rubber sheet 3 was very thin, the tip of the rubber sheet 3 was rounded and tightly adhered at the time of assembling into a tab product. On the other hand, in the present invention, by providing the rib 7 on the end face of the rubber sheet 3, the rigidity of the end face is increased, the adhesion due to rounding or the like is lost, and the step of peeling is abolished. Those that did not occur with the present invention.

By providing the ribs 7 on the entire circumference of the rubber sheet in the same manner, the rib 7 can be formed when the rubber sheet is formed by compression molding or the like, and the steps such as cutting and washing can be simplified.

Experimental Example In FIGS. 1 and 2, the thickness of the rubber sheet 3 is 0.2 m.
m, the height of the rib 7 was set to 0.6 mm.
Was almost the same as the height. In addition, film gate 5
The thickness of the resin was made substantially the same as the thickness of the rubber sheet to ensure the fluidity and cutability of the resin. Further, the length of the film gate was set to 0.5 mm, and the position of the film gate 5 was set to a position substantially at the center of the thickness of the ribs 6 and 7. The minute through hole 8 was a round hole having a diameter of 0.4 mm.

As described above, the rubber sheet 3 formed integrally with the fan-shaped gate can be used without using a cutter as in the conventional case.
The ribs 6 and 7 can be easily cut by simply grasping them by hand and pulling them. Further, the variation in the outer dimensions was 0.5 mm or less, which was within the length of the film gate 5, and the dimensional accuracy was remarkably improved.

As described above, according to the present invention, since the thick portions thicker than the thickness of the film gate are formed on the rubber sheet side and the runner side of the film gate so as to face each other, the film gate is pulled so as to widen the gap. Only the thin film gate is cut, and the rubber sheet does not tear, and the length of the film gate remaining on the rubber sheet side is also constant. Improved. In addition, since a through-hole in the thickness direction is provided in the film gate, when pulling so as to widen the thick portion, stress concentrates on the through-hole, so that the film is torn from that part, improving tearing workability and cutting. Since the position is fixed, the quality can be improved. Making the length of the film gate between the thick portions 1 mm or less is effective because the film gate remaining on the rubber sheet side becomes small.

[Brief description of the drawings]

FIG. 1 is a front view showing an outline of a rubber sheet of the present invention.

FIG. 2 is an explanatory diagram for explaining details of the present invention.

FIG. 3 is a front view of a conventional rubber sheet.

FIG. 4 is an explanatory view of a conventional rubber sheet.

FIG. 5 is an explanatory diagram for explaining another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spool 2 Fan gate 3 Rubber sheet 4 Cut surface 5 Film gate 6 Rib 7 Rib 8 Micro through hole

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 1/00 B29C 45/26-45/37

Claims (3)

(57) [Claims] 1. A are more prepared to injection molding, the mold
A rubber sheet for a printer having a film gate formed at a gate section , wherein a thicker portion than the thickness of the film gate is formed on the rubber sheet side and the runner side of the film gate so as to face each other. Sheet. 2. The film gate according to claim 1 ,
The rubber sheet according to claim 1, wherein a through hole is provided. 3. The rubber sheet according to claim 1, wherein the length of the film gate between the thick portions is 1 mm or less.