JPH0816776B2 - Method for manufacturing disc for controlling winding diameter of photo film - 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 of manufacturing a roll diameter controlling disk for a photographic film.

[0002]

2. Description of the Related Art In a photographic film cartridge, a film wound around a spool is stored inside the cartridge body. The spool is composed of a spool shaft that is a winding shaft of the film and a disc that shields the film, and is manufactured by injection molding of resin. In addition, a photographic film cartridge has been proposed in which the tip of the film is wound into the main body of the cartridge even when it is unused, so that it can be loaded into the camera like a cassette. In this type of photo film cartridge, the rotation of the spool shaft is transmitted to the tip of the film by preventing the film from being loosened so that the tip of the film can be sent out of the cartridge body by the rotation of the spool shaft. Among them, US Pat. No. 4,834,306
In the photographic film cartridges disclosed in Japanese Patent No. 4848693 and No. 4848693, a lip is formed on the peripheral edge of the disc to prevent the winding from loosening, and the lip is wrapped around the end of the film. I have to.

By the way, in this photographic film cartridge, when the film is sent out of the cartridge main body, a projection is pressed against the lip or the disk to release the wrapping of the end portion of the film. There is a problem that the driving torque becomes large.
When the lip and the disc have a thin wall thickness, for example, 0.4 mm or less, the above problem can be solved and the film can be fed out with a low torque.

[0004]

However, in the above-mentioned conventional manufacturing method, when the disk is made thin, the flow resistance of the resin becomes large and shorts, shots, burrs, etc. occur, and the disk is made into a mold. Since it is electrostatically adsorbed on the aluminum plate and it becomes difficult to take it out, the moldability and mass productivity are deteriorated, and it has been impossible to manufacture at low cost.

An object of the present invention is to provide a method for manufacturing a photographic film winding diameter regulating disk which is inexpensive and has good moldability and mass productivity.

[0006]

In order to achieve the above object, in the production method of the present invention, a sheet of a thermoplastic resin containing a lubricant having a flow index of 4 or less and a wall thickness of 0.1 mm to 0.4 mm. Is softened by heating and then molded by a die, and thereafter, an opening for spool insertion is formed in the center portion by a punching machine, and the winding diameter regulating disk is cut from the sheet.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 4 showing a photographic film cartridge using a roll diameter regulating disc manufactured by the manufacturing method of the present invention, this photographic film cartridge 2 is a cartridge main body 3 consisting of two casings 3a and 3b, and The spool 4 is housed inside, and the film 5 is wound around the spool 4 in a roll shape. The spool 4 is composed of a spool shaft 6 and a pair of disks 7 and 8 which are freely penetrated by the spool shaft 6. Each disk 7, 8 on the spool shaft 6
Washers 9 and 10 are fitted on the outer sides of, respectively, and these washers 9 and 10 block external light entering along the direction of the spool shaft 6.

At the joint between the casings 3a and 3b, a delivery port 15 for taking in and out the film 5 is formed. A pair of guide protrusions 16 and 17 are formed on the casing 3a so as to correspond to the delivery port 15. The guide protrusions 16 and 17 contact the insides of the disks 7 and 8 to spread them in the film width direction. , Release the film loosening prevention. Separation claws 18 are formed on the casing 3b so as to correspond to the guide protrusions 16. The separating claw 18 engages with the leading end of the film 5, separates it from the lower film surface, and guides it to the delivery port 15. The outlet 15
Telemps 19 and 20 are vertically joined so that external light does not enter the inside of the cartridge body 3. Further, on the inner wall of the lower side of the casing 3a, there are formed protrusions 21 and 22 which come into contact with the discs 7 and 8 from the outside.
22 presses the end portion of the film 5 via the disks 7 and 8.

2 and 3 show a first embodiment of the disk. Since the disks 7, 8 are the same in shape, material, and action, only the illustrated disk 7 will be described. An opening 40 for inserting the spool shaft 6 is formed in the center of the disk 7, and an arc-shaped lip 41 for preventing the film 5 from being loosened is formed on the peripheral edge of the disk 40 in contact with the outermost peripheral edge of the film 5. Has been done. This lip 4
As shown in FIG. 3, No. 1 is formed in a J shape, and the surface in contact with the film 5 is made smooth. Therefore, the separation claw 18
As a result, the frictional resistance between the film 5 and the lip 41 to be scooped up can be reduced. Further, a collar 42 that abuts the guide protrusions 16 and 17 is formed at the folded tip of the lip 41.

FIG. 1 shows a manufacturing process of the disc. In the figure, the film feeder 25 has a thickness of 0.
A roll 27 of polyethylene film 26 having a width of 3 mm and a width of 1000 mm is set. In order to maintain the strength of the resin, the polyethylene film 26 is made of, for example, Courton S8000 (high density polyethylene) having MI (melt index) 1.0 showing a flow index. The polyethylene film 26 is sent to a vacuum forming machine 29 by a roller 28, and the pair of heaters 3 in the vacuum forming machine 29 is fed.
It is heated at 200 ° C for 10 seconds by 0,31. After heating, the softened polyethylene film 26 is sent to the molding section 32.

The molding part 32 is composed of a pair of metal molds 33 and 34 for taking 39 pieces in 13 × 3 rows. These molds 33 and 34 are heated to 80 ° C. during molding. The vacuum pump 3 is attached to the die 33 via a suction hose 35.
6 is connected. The polyethylene film 26 is sucked by the vacuum pump 36 and adheres to the mold 33. This suction is continued for 5 seconds after the close contact. After that, the mold 34 is raised, and the polyethylene film 26 is sandwiched between the mold 33 and the mold 33. In this manufacturing method, after the vacuum forming, the polyethylene film 26 is placed in the molds 33, 3 in order to improve the formability.
Although the pressure was clamped by 4, the mold 34 may be omitted if the manufacturing cost of the mold is increased. Although the polyethylene film 26 is vacuum-molded in the above manufacturing method, the polyethylene film 26 may be pressure-molded and hot-press molded.

In this state, the polyethylene film 26 is 5
After being cooled for a second, it is sent to the punching machine 37. Punching machine 37
Then, the disc 7 shown in FIG. 2 is die-cut from the polyethylene film 26. At this time, the opening 40 is formed in the central portion of the disk 7. In FIG. 3, assuming that the outermost diameter of the disk 7 is Φ1, the height is H, the diameter of the opening 40 is Φ2, and the wall thickness is D, the specifications are Φ1 = 20 mm, H = 1.8 m.
m, Φ2 = 8 mm, D = 0.3 mm. The discs 7 thus stamped are discharged into a container 38 provided in the punching machine 37 and accumulated. When a certain amount of disks 7 are accumulated, the container 38 is sent to the film winding step by a conveyor or a self-propelled vehicle. Here, the disk 7 is incorporated in the spool shaft 6.

In the thermoforming described above, the thickness of the molded product can be made uniform and thin up to 0.1 mm without impairing mass productivity. Further, in the above-described manufacturing process, the disk 7 was thermoformed with one polyethylene film 26, but it may be thermoformed with a film laminated with two or more layers. Furthermore, in this embodiment, in order to improve the moldability, the polyethylene film 26 was vacuum-molded and then pressed by the mold 34. However, when a blade is formed on the mold 34 and die cutting is performed here, the punching process is performed. Can be omitted.

In the photographic film cartridge 2 described above, the wall thickness D of the disk 7 is set to 0.3 mm and they are pushed out with a small force. If this wall thickness D is 0.4 mm or less, the same effect can be obtained. You can Although the disk 7 is thermoformed with the polyethylene film 26, other films such as polystyrene, polyvinyl chloride, polypropylene and ABS resin may be thermoformed.

By adding additives or lubricants to the polyethylene film 26, the frictional resistance between the film 5 and the lip 41 can be further reduced. The additives include fluorine powder, silicone oil, carbon fiber, molybdenum difluoride, graphite, potassium titanate, etc., and the lubricants include silicone oils, higher fatty acid amides such as oleic acid amide and erucic acid amide. , metal salts of higher fatty acids such as zinc stearate, higher alcohol esters, fatty acid esters of polyhydric alcohol esters there.

When the photo film cartridge 2 is loaded in the camera, the spool shaft 6 is rotated in the film feeding direction by the film initial feeding mechanism of the camera. At this time, the outermost edges of the film 5 are pressed by the lip 41, so that the rotation of the spool shaft 6 is transmitted to the tip of the film 5. As a result, the leading end of the film 5 is rotated clockwise with the roll-shaped film 5 in FIG. At this time, the rotation of the spool shaft 6 is transmitted from the film 5 to the disks 7 and 8 via the lip 41. At this time, the guide protrusions 16 and 17 are in contact with the collar 42, but since the disks 7 and 8 are formed in a thin thickness so as to be easily deformed, the rotational torque of the spool shaft 6 does not increase.

When the spool shaft 6 is further rotated, the leading end of the film 5 abuts on the separation claw 18 and the lower film 5 is contacted.
Scooped from the surface of. Further, at this position, as described above, the guide protrusions 16 and 17 allow the disc 7,
8 is deformed, and the restriction of both ends of the film 5 by the lip 41 is released. Therefore, the leading end of the film 5 slides on the upper surface of the separation claw 18 and is fed out of the cartridge body 3 from the delivery port 15.

The above-mentioned photographic film cartridge using the disk 7 having a wall thickness of 0.3 mm and the photographic film cartridge using a disk having an injection molding thickness of 0.5 mm are used for feeding torque, molding cost, and abnormal noise during feeding. The results are as follows. The disc 7 was excellent in any comparison, even if the material was polyethylene, polypropylene, polyvinyl chloride, or polystyrene.

FIG. 5 shows another photographic film cartridge using the disk embodying the present invention. In this photographic film cartridge, the spool 45 is composed of two parts, a spool shaft 45a and a spool shaft 45b which are axially fitted to each other. A cam groove 46 is formed at one end of the spool shaft 45a, and a locking portion 47 for fixing the disk 7 with an adhesive is formed at the other end. A cam follower 48 corresponding to the cam groove 46 is provided at one end of the spool shaft 45b, and the lip 4 described above is provided at the other end.
Discs 49 without 1 are integrally formed.

In the spool 45 thus constructed,
When the spool shaft 45b is rotated clockwise in the figure, the action of the cam follower 48 and the cam groove 46 causes the spool shaft 4 to rotate.
5a moves so as to approach. By this movement, the lip 41 is engaged with the side end portion of the film 5 to prevent winding looseness. As a result, the rotation of the spool shaft 45b is transmitted to the tip of the film 5, and the tip of the film 5 moves to the spool 4.
Rotate clockwise with 5. The spool shaft 45a
When is moved, a guide projection (not shown), not shown, comes into contact with the lip 41, but the lip 41 is easily deformed, so that the rotational torque of the spool shaft 45b is not increased.

FIG. 6 shows a photographic film cartridge using a disc having a notch. In this photo film cartridge, a cross-shaped engaging projection 53 is formed at the front end of the spool shaft 52, and a notch 55 is formed in the front disk 54 correspondingly. An engaging projection 53 is formed on the rear end of the spool shaft 52, and a notch 55 is formed on the rear disk 56. In the photographic film cartridge constructed as described above, when the disc 55 is fitted into the spool shaft 52,
Since the engagement projection 53 and the notch 55 mesh with each other, the rotation of the spool shaft 52 can be reliably transmitted to the disks 55 and 56.

7 to 9 show another shape of the disk embodying the present invention. In the second embodiment shown in FIG. 7, the disk 60 is formed with a J-shaped lip 61 without a collar. In this disc 60, the guide protrusions 16 and 17 described above are brought into contact with the folded end of the lip 61,
The disc 60 is bent outward. FIG.
In the third embodiment shown in FIG. 3, an L-shaped lip 6 is attached to the disc 63.
4 is formed. In this disc 63, the guide protrusions 16 and 17 are brought into contact with the folded-back portions, so that the disc 63
Is bent outward. In the fourth embodiment shown in FIG. 9, a disk 65 is provided with an L-shaped lip 66 having a short folded portion.

[0023]

As described above in detail, according to the method for producing a roll for controlling the winding diameter of a photographic film of the present invention, the flow index is 4 or less and the wall thickness is 0.1 mm to 0.
After heating and softening a sheet of thermoplastic resin containing a 4mm lubricant, and a mold, and thereafter, spool in a punching machine
Since the winding diameter regulating disk is cut from the sheet while forming the opening for inserting the reel, the moldability and mass productivity can be improved, and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view showing a manufacturing process of a disc of the present invention.

2 is a first disc manufactured by the manufacturing process shown in FIG.
It is a perspective view showing an example.

FIG. 3 is a cross-sectional view of the disc shown in FIG.

FIG. 4 is an exploded perspective view showing a photographic film cartridge using the disc shown in FIG.

5 is an exploded perspective view showing another photographic film cartridge using the disc shown in FIG.

FIG. 6 is an exploded perspective view showing another photographic film cartridge using a disc having a notch.

FIG. 7 is a partial cross-sectional view with a part broken away of a second embodiment of the disc.

FIG. 8 is a partial cross-sectional view with a part broken away of a third embodiment of the disc.

FIG. 9 is a partial cross-sectional view with a part broken away of a fourth embodiment of the disc.

[Explanation of symbols]

2 Photo film Patrone 3 Patrone body 5 Film 6 Spool shaft 7, 8, 49, 54, 56, 60, 63, 65 Disc 41, 61, 64, 66 Lip

Claims (1)

[Claims] 1. A opening for inserting the spool shaft is formed at the center, pictures on the periphery of the annular projection to prevent the winding looseness by suppressing the outermost periphery of the photographic film wound on the spool shaft is formed In the method for manufacturing a disc for controlling a roll diameter of a film, the flow index is 4 or less and the thickness is 0.1 mm to 0.4 m.
A thermoplastic resin sheet containing a lubricant of m is heat-softened and then molded by a mold, and thereafter, the opening is formed by a punching machine and the winding diameter regulating disc is cut from the sheet. A manufacturing method of a disc for controlling a winding diameter of a photographic film.