JP3126568B2 - Method of manufacturing flange for film cartridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a component constituting a cartridge used for storing a photographic roll film in a light-shielded state. In particular, the present invention relates to JP-A-3-214153 and U.S. Pat. No. 5,031,852.
And a method for manufacturing a flange in a cartridge disclosed in Japanese Patent Application Laid-Open Publication No. H10-209,873.

[0002]

BACKGROUND OF THE INVENTION 35 mm roll films, which are widely used at present, are housed in light-shielding containers called patrone, and are long films having continuous through holes called perforations on both sides. The base end is fixed and wound around a spool shaft in the cartridge, and a leader portion is drawn out through a slit in which a so-called light-shielding fiber material is arranged.

[0003] The patrone for accommodating a 35 mm roll film which is commercially available in Japan is made of metal. However, there are problems in manufacturing cost, loading in a camera, downsizing,
There is a problem of reuse and the like, and patrones or cartridges made of various synthetic resins (in the present specification, the cartridges are unified) have been proposed.
No. 153 and U.S. Pat. No. 5,031,852.

The cartridges described in these publications are cartridges as shown in FIG. 6, which is greatly different from the currently used 35 mm roll film cartridges for photography. It is made of synthetic resin, the leading edge of the film is drawn into the container and there is no exposed leader, or only a small part of the leading edge of the film is exposed. It is possible to take out and put in the film. These are so-called leader-less types, and have various functions that are not present in conventional metal cartridges, such as having a function of winding the leading end of the film 53 inside the cartridge body 50 or extruding it outside. Technology is employed.

In order to wind the film 53 into the cartridge body 50, it is only necessary to fix the base end of the film 53 to the spool shaft 54 and rotate the spool shaft 54 in the film winding direction. There is no difference from the structure. However, in order to form a structure in which even the leading end of the film 53 is wrapped inside the cartridge body 50, it is necessary to consider pushing the film 53 out of the cartridge body 50 again. Has been adopted.

That is, as shown in FIG.
A flexible synthetic resin flange 60 is provided at both ends of the film 53 so as to be sandwiched between the hubs 55 and 56. The rising portions 61 of the flange 60 allow both ends of the film 53 wound around the spool shaft 54. The part is pressed down, and it is regulated that the film 53 becomes loose and spreads like a mainspring. As described above, since the winding of the film 53 is not loose, the hub 5
The leading end of the film 53 can be pushed out of the cartridge main body 50 in accordance with the rotation of the spool shaft 54 by the operations 5 to 56. On the other hand, Japanese Unexamined Patent Publication No.
No. 1 discloses a method of manufacturing the above-mentioned flange by a vacuum forming method.

[0007]

Generally, synthetic resin molding methods include hot press molding using a resin sheet as a material, vacuum molding, and injection molding using a resin pellet as a material, all of which are industrially inferior. It is known as an influential method. However, as a result of repeated examinations of prototypes by the present inventors, surprisingly, with the flange created by the method described in Japanese Patent Application Laid-Open No. Hei 4-251841, the torque of pulling out and rewinding the film for each patrone was remarkably increased. It was found that the values varied widely and had unexplained adverse effects on the photographic performance of the undeveloped film. Further, U.S. Patent Nos. 4,864,332 and 4,965,627
When a film provided with a magnetic recording layer as disclosed in Japanese Patent Application Laid-Open No. 4-2511841 is used for a patrone using a flange prepared by the method described in Japanese Patent Application Laid-Open No. Hei 4-251841, a defect of unknown cause is found. Was done.

[0008] In view of the above, the present invention provides a method of manufacturing a flange having a constant quality, with little deterioration in the performance of a film to be loaded, with high production efficiency, and without increasing production cost. The purpose is to do.

[0009]

According to a method of manufacturing a flange for a film cartridge of the present invention, which achieves the above-mentioned object, a flange is inserted into a spool shaft of a film cartridge, and
In a method of manufacturing a flange made of a synthetic resin material to be used for preventing a photographic film wound around a spool shaft from being loosened, a gate is provided upright at a rising portion continuous with a peripheral edge of a flat plate portion of the flange. It is manufactured by an injection molding method using a mold that has been set, to manufacture a flange provided with a flange having a width of 0.2 mm to 1.0 mm at the end of the rising portion of the flange, As the synthetic resin material, a resin selected from polypropylene, polyethylene, polystyrene, ABS, and ionomer resin is used, respectively.

[0010]

Next, the method of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 illustrates a flange 10 manufactured by the method of the present invention. This flange 10 has a flat plate portion 11 provided with a central opening 12 to be inserted into a spool shaft of a cartridge (not shown) and an opening 13 for controlling the rotation direction.
The rising portion 14 that regulates the rewinding of the film on the inner side is continuous with 1, and a flange portion 15 that reinforces the rising portion is disposed at an end of the rising portion 14.

In FIG. 1, the parting line of the injection molding is indicated by a dashed-dotted line 16, and the remaining portion 17 of the gate is shown at the rising portion 14 on the parting line 16. By the way, when the flange 10 having the shape shown in FIG. 1 is to be molded by the injection molding method, if the mold is to be molded by two molds, a male mold and a female mold, the possible gate positions are as follows. The end of the spool is directly or directly connected to the molded product and does not require a runner. The end or flat portion of the flat plate portion 11 and the flange portion 15 as a direct gate, the inside of the central opening 12 as a disk gate, and the flat plate portion 11 to 10 as an annular gate. The periphery of the flange 15 can be considered. However, when gates are provided on the flat plate and the flange, if there is a remaining gate at these positions, there is contact with other members or damage to the film. There is a danger of giving it, and an operation of sufficiently removing the remaining gate is required as a post-process after molding.

In the case of a disk gate, a gate residue that damages the film does not occur, but if a gate residue occurs due to a change in molding conditions or the like, a film-shaped gate residue occurs inside the central opening, and the spool shaft When it is inserted, the clearance between the hub and the hub becomes small due to the remaining gate, so the rotation of the flange is combined with the movement of the spool shaft, so that it does not become one way and jamming occurs at the time of winding May be.

On the other hand, the gate position is set to the flange 10
2, even if the gate remains as the remaining portion 17, if the height of the remaining portion 17 of the gate is lower than the height of the flange portion 15, as shown in FIG. There is no need to perform a post-processing step such as excision because it does not cause any obstacle. The width of the flange portion 15 provided at the end of the rising portion 14 of the flange 10 is 0.2 mm in consideration of the strength of the film holder at the rising portion, ease of resin insertion, and ease of manufacturing a mold. ~ 1.0mm,
Desirably, it is 0.2 mm to 0.5 mm.

As a molding material, a synthetic resin material such as polypropylene, polyethylene, polystyrene, ABS, and ionomer is used.
It is desirable to use polyethylene, polypropylene, and ionomer resin. In addition, by setting the gate position as shown in FIGS. 1 and 2, multi-cavity injection molding as described later becomes possible.

FIG. 3 shows an injection molding apparatus and a molding die.
This device is composed of a part of a flange forming die and a part of an injection molding device. The mold for forming a flange includes a fixed mold and a movable mold, and a molding space (cavity) for molding the flange shown in FIGS. A gate for injecting and injecting the molten resin is communicated with the molding space (cavity), and the molten resin is injected from outside the mold through the gate. In FIG. 3, the molding space (cavity) is shown.
Although only two are shown for convenience, the normal molding space has a larger number of spaces formed therein, and the resin is injected into these spaces at once.

The injection device 102 is a so-called screw type injection device, and has a heating cylinder 1 for heating and melting a molding material.
08, a band heater 114 arranged so as to surround the heating cylinder 108, a screw 113 for kneading the molten resin and injecting it into a mold, a hydraulic cylinder 110 having a piston 116 for applying an ejection power to the screw 113, and the screw It has a hydraulic motor 112 for applying a rotational force to a 113 via a reduction gear 111, and a hopper 109 for supplying a molding material to the heating cylinder. Therefore, the amount of the injected resin is determined by the stroke of the piston 116.

FIG. 4 shows the arrangement of cavities and the arrangement of runners in the case of 16 cavities as an example of multiple molding. In the case of multi-cavity molding, the runner distance from the spool to each cavity is made equal so that each cavity is filled with resin at the same time. The cross-sectional shape of the runner is most preferably a circular shape having a small flow resistance of the resin, but may be a semicircular shape or a trapezoidal shape.

FIG. 5 is a schematic view of a mold showing another embodiment of the method of the present invention. In this embodiment, injection molding is performed by two molds, a fixed mold A and a movable mold B, and a gate is formed. 25 is a submarine gate. The submarine gate has an advantage that it can be used in a two-plate type structure.
This is a gate having a structure in which a conical hole provided in the fixed or movable mold plate at an inclination of about 45 degrees communicates with the side surface of the cavity. Note that the submarine gate can also be used in the molding method shown in FIGS.

[0019]

EXAMPLE Using a polyethylene resin, FIG.
The inner diameter d ₁ and an outer diameter d ₂ on the side for accommodating the film same west, the thickness of the rising portion _{14 (d 2 -d 1) /} 2 is 0.
The method according to the present invention and the method disclosed in
A plurality of flanges were respectively prepared by the method (vacuum forming) described in Japanese Patent No. 251841 and incorporated into a patrone.
Evaluation was performed by the method described below. FIG. 8 shows the results.

A film with a magnetic layer is accommodated in this patrone, and when the operating temperature of the camera is low (−20 ° C.) and high (60 ° C.) using an evaluation device as shown in FIG. Was changed with a weight placed on an acrylic plate, and a feeding test was performed. The film is fed if the feeding torque including the resistance is larger than the feeding torque of the camera. Cameras that use a film with a magnetic layer have a magnetic head for recording and playback, and have a resistance other than that of the pressure plate to secure the film flatness of the exposed part, unlike a conventional camera. In addition, it is necessary that the film be wound around the take-up spool without breaking against these resistances. In FIG. 8, the horizontal axis represents the weight load,
The vertical axis shows the delivery load.

As a result of the evaluation, the patrone using the flange prepared by the method of the present invention at a low temperature or at a high temperature was compared with the patrone prepared by the method described in Japanese Patent Application Laid-Open No. Hei 4-251841. Even with the same resistance in the camera, surprisingly, the flange made by the method of the present invention has a larger sending torque, even if the same resistance is present in the camera,
It is clear that the variation in torque among products is small. Therefore, even if the resistance to be applied varies depending on the type of camera, it is advantageous to use a patrone using the flange made by the method of the present invention, since the film can be fed without any problem.

[0022]

According to the method of the present invention, the quality is constant,
Further, the post-molding post-processing step of cutting off the gate remaining portion 17 is not required, which is useful for reducing the production cost and improving the production efficiency. In addition, damage to the film emulsion surface and the magnetic recording layer in the patrone is prevented. It is possible to provide a flange capable of providing a film cartridge that does not cause deterioration and that consumes less battery in the camera.

[Brief description of the drawings]

FIG. 1 is a perspective view of a flange.

FIG. 2 is a sectional view of the same.

FIG. 3 is a schematic sectional view of an injection mold.

FIG. 4 is a perspective view showing a molded state.

FIG. 5 is a schematic sectional view showing another embodiment of the injection molding die.

FIG. 6 is an exploded perspective view of the cartridge.

FIG. 7 is an exploded perspective view centering on the spool shaft.

FIG. 8 is a graph showing the experimental results of the example.

FIG. 9 is a schematic diagram of an evaluation device according to an embodiment.

[Explanation of symbols]

 Reference Signs List 10-flange 11-flat plate 12-center opening 13-rotation control opening 14-rise portion 15-flange portion 16-parting line 17-remaining gate 20-female 1 type 21-female 2 type 22-male 1 Type 23-Male 2 Type 24-Runner 25-Gate

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Claims (3)

(57) [Claims] 1. A method of manufacturing a flange made of a synthetic resin material which is inserted into a spool shaft of a film cartridge and is used to prevent loosening of a photographic film wound around the spool shaft. A method for manufacturing a flange for a film cartridge, wherein the flange is manufactured by an injection molding method using a mold having a gate set up in a rising portion continuous with a peripheral edge of the portion. 2. The end of the rising portion of the flange is provided with 0.1.
The method for producing a flange for a film cartridge according to claim 1, wherein a flange provided with a flange having a width of 2 mm to 1.0 mm is produced. 3. The method according to claim 1, wherein a resin selected from the group consisting of polypropylene, polyethylene, polystyrene, ABS, and ionomer resin is used as the synthetic resin material.