JP3034103B2 - Film driven sprocket for film unit with lens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sprocket shaft and a sprocket.
Film unit with lens that fits easily into the
The present invention relates to a film driven sprocket for a vehicle .

[0002]

2. Description of the Related Art A film unit with a built-in photo film and a lens having a simple photographing function (for example, a product name " It is H
i ") is commercially available by the applicant. Since the film unit with a lens needs to be provided at a price that is not so different from the purchase of a normal color film, the entire structure is simple. In addition, a structure that allows automatic assembly as much as possible is adopted so that mass production is possible.

In this film unit with a lens, the film is wound up by rotating a knob, and the film transfer force at this time is converted into a rotational force by a sprocket engaging with the perforation to charge the shutter of the shutter mechanism. Like that. When a film having a length of one frame is fed, the rotation of the sprocket is regulated by the shutter mechanism, whereby an unexposed film is set on the exposure frame.

[0004]

The above-mentioned sprocket has the following features.
In the film transfer path of the unit main body, it is arranged in the sprocket receiving recess at a position corresponding to the perforation. A square hole is formed in the sprocket, and the tip of the sprocket shaft associated with the shutter mechanism is fitted in the shaft hole. When assembling this sprocket with the sprocket shaft,
First, after loading the sprocket into the storage recess, insert the sprocket shaft from the bearing of the unit body, align the sprocket shaft with the shaft hole of the sprocket, and fit the tip of the sprocket shaft into the shaft hole. I have. Since the shaft hole of the sprocket is formed of a square hole so that the sprocket shaft does not run idle, there is a problem that it is difficult to perform positioning for inserting the sprocket shaft into the shaft hole. In particular, since it is necessary to align the two with the sprocket placed in the storage recess, the shaft hole cannot be visually confirmed, and the work must be performed while groping. There is a problem that efficiency is reduced. In addition, since it is necessary to align the two, there is a problem in performing the automatic assembly, and there is a problem that the sprocket cannot be efficiently incorporated into the unit body.

On the other hand, at the shaft tip and the edge of the shaft hole,
By forming an inclined surface (tapered surface) to serve as an insertion guide surface, it is conceivable that the two can be easily fitted. However, a plastic molded product is used for the sprocket of the lens-fitted film unit in order to reduce cost and weight. Furthermore, in order to allow the sprocket shaft to be inserted regardless of the front and back of the sprocket, when trying to form the above-mentioned slope on the front and back of the sprocket, due to restrictions on the processing of the mold used during molding, as shown in FIG. At one end of the sprocket 1, a step surface 4 composed of a mold dividing surface is formed between the inclined surface 2 and the hole edge 3a of the shaft hole 3. Therefore, when the sprocket shaft 5 is inserted into the shaft hole 3 in a state where the two cores are displaced, the tip of the sprocket shaft 5 hits the step surface 4 and the insertion of the sprocket shaft 5 is prevented. For this reason, there is a problem that the sprocket 1 made of a plastic molded product using a mold cannot cope well during automatic assembly.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a film driven sprocket of a film unit with a lens is provided.
When assembling with a rocket fitted,
The split surface of the mold on the sprocket body does not
And even if there is misalignment between them,
Film with film unit with lens that can be fitted
It is an object of the present invention to provide a gear driven sprocket .

[0007]

In order to achieve the above-mentioned object, the invention according to claim 1 comprises a sprocket shaft and a sprocket shaft.
Insert the fitting hole into which the propet shaft is inserted and
In the center, remove the pawl that engages the film perforation.
Sprockets, each of which has an injection molding
For the film unit with lens consisting of
In the Ilm driven sprocket, the sprocket shaft
Tapered at the tip of the sprocket shaft
The first surface, which serves as a guide surface when fitted to the sprocket body,
Opening at both ends of the fitting hole of the sprocket body
Formed on the edge so that it gradually spreads outward
And a second guide surface serving as a guide surface when the sprocket shaft is fitted.
And a second slope formed on one of the second slopes.
Formed so as to cut off the intersection of the surface and the fitting hole surface,
Step portion having a step surface intersecting the center line of the fitting hole
And a second slope of the step surface in the step portion.
The length is set shorter than the length of the first slope,
The step surface is the same as the mold split surface during injection molding of the sprocket body.
It was done. Therefore, the front and back of the sprocket body
Regardless of which sprocket shaft is inserted, the mold during molding
Easy insertion work without being affected by the split surface
Can be .

[0008]

[0009]

[0010]

FIG. 3 shows a film unit with a lens (hereinafter simply referred to as a film unit) embodying the present invention. The film unit 10 includes a unit main body 11 having a photographing mechanism and an outer case 12 for housing the same. A photograph is taken while the film unit 10 is kept in the outer case 12. Outer case 12 is film unit 1
0 is used to make the appearance of the printer beautiful, and a paper box having an outer surface printed thereon is used. The outer case 12 includes a photographing lens 13, an object-side finder window 14, an eyepiece-side finder window 15, a shutter button 16,
7, a hole for exposing the winding knob 18 and the strobe light emitting section 19 are provided.

FIG. 4 shows the unit main body 11. The unit main body 11 includes a main body 20, a front cover 21,
And a rear cover 22. On the front surface of the main body 20, a shutter unit 25 in which the photographing lens 13 is arranged and a strobe unit 26 that holds the light emitting unit 19 are provided. A patrone chamber, an exposure chamber and a film chamber (not shown) are formed on the back side of the main body 20 from the left side in the figure, and the film 23 with the patrone is loaded on the back side of the main body 20. In this state, the rear cover 2
2 is detachably attached to the main body 20 by a claw.
The rear cover 22 is provided with a bottom cover 24 for opening and closing the cartridge in which the film is rolled out after the photographing is completed. The film transfer path 27 is located at a position where the perforations 23a of the film 23 pass.
A sprocket escape recess 27a is formed.

In FIG. 5 showing the shutter unit 25, a shutter unit base 3 having an exposure opening 28 is shown.
In FIG. 0, a positioning hole 31 for positioning when this is attached to the main body 20 and claw receiving portions 30a and 30b are integrally formed on both sides of the exposure opening. The shutter unit base 30 has a plastic shutter blade 34 urged counterclockwise by a spring 33.
A shutter cover 35 for holding the taking lens 13 is attached to the shutter unit base 30 so that the shutter blades 34 do not fall off.

On the upper part of the shutter unit base 30, shafts 30c and 30d and a bearing 30e are formed. A shutter driving cam 39 having a number-of-shots display plate 38 and a shutter driving lever 39a is provided on the shaft 30c, and a locking lever 41 biased clockwise by a spring 40 is provided on the shaft 30d in a rotatable manner. Have been. This locking lever 41 normally engages with a shutter driving lever 39a urged in a counterclockwise direction by a spring 40 to prevent the rotation of the shutter driving cam 39, and a shutter button (see FIG. 3).
When the shutter 16 is pressed, the shutter drive lever 39a is pressed.
Release the engagement with. When the engagement with the locking lever 41 is released, the shutter drive lever 39a is rotated counterclockwise by the spring 40, and the arc-shaped pressing surface 39b formed on the shutter drive lever 39a is brought into contact with the claw of the shutter blade 34. The part 34a is pressed.

A sprocket shaft 44 serving as a shaft of a cam 43 engaged with the locking lever 41 is inserted through the bearing 30e. The sprocket shaft 44 is fitted into the shaft hole 46 of the driven sprocket 45 via the tip fitting portion 44a. Therefore, the film winding knob 18 (FIG. 3)
When the film is wound up by rotating the sprocket 45, the sprocket 45 rotates counterclockwise, whereby the cam 43 also rotates counterclockwise, and the cam arm 39c formed on the shutter drive cam 39. , The shutter drive lever 39a returns to the initial position.
8 rotates by one division.

As shown in FIG. 6, the sprocket shaft 4
An inclined surface 47 formed by chamfering is formed in the front end fitting portion 44a of No.4. This inclined surface 47 is formed as a conical surface by chamfering the tip in a conical shape, and serves as a guide surface when the tip fitting portion 44a is inserted into the shaft hole 46 of the sprocket 45. The sprocket shaft 44 is integrally rotated by the rotation of the sprocket 45, and is used as a drive shaft for driving a shutter charging mechanism and a counter mechanism by the rotation of the sprocket 45.

In the driven sprocket 45, positioning disks 50 are formed on both end surfaces thereof so as to project concentrically with the shaft hole 46. As shown in FIG. 7, bevels 51 and 52 are formed at both ends of the shaft hole 46. The driven sprocket 45 is manufactured by injection molding using a mold as is well known. For this reason, as shown in FIG. 2, conventionally, a step surface 4 is formed on one slope 2 by a dividing surface of a molding die. The step surface 4 is formed between the edge of the shaft hole 3 and the slope 2 so that burrs during molding do not occur in a direction orthogonal to the center line CL1 of the shaft hole 3. In the present invention, as shown in FIG.
A step portion having an inner diameter larger than the shaft hole 46 is formed at the back of the shaft hole 46, and a step surface 54 serving as a division surface is formed on the back side of the intersection D between the extension line A of the slope 52 and the extension line B of the inner surface of the shaft hole 46. You have set. The length of the extension line A (line segment DE) connecting the end point E on the far side of the slope 52 and the intersection D (the length of the step surface 54 corresponding to the slope ).
) Is set shorter than the length of the slope 47 of the tip fitting portion 44 a of the sprocket shaft 44.

As a result, as shown in FIG. 7, even when the center line CL1 of the sprocket 45 and the center line CL2 of the sprocket shaft 44 do not coincide with each other and are shifted by the shift amount Δ, the tip 44b of the sprocket shaft 44 remains Since the guide is guided into the shaft hole 46 without hitting the step surface 54, the sprocket shaft 44 can be smoothly inserted into the sprocket 45. At this time, the allowable deviation amount Δa is the height C1, C of the two slopes.
2, which is less than the sum C1 + C2, so that the allowable amount increases by C2 as compared with the conventional case shown in FIG. 2, and it is possible to cope with the case where the misalignment amount increases.

As shown in FIG. 6, the driven sprocket 45
Is inserted into a sprocket housing recess 60 provided on the back side of the shutter base 30. Sprocket storage recess 60
Is composed of an arc-shaped groove having an inner diameter slightly larger than the outer diameter of the sprocket 45. The sprocket receiving recess 60 is provided with the driven sprocket 4
5, the teeth 45 a of the sprocket 45 slightly protrude from the film transfer path 27 (see FIG. 3), and are formed to a depth that engages with the perforations 23 a of the film 23 passing through the film transfer path 27. I have. When the sprocket 45 is inserted into the recess 60, the positioning disk 50 is
Guide groove 6 into which positioning disk 50 enters at a position corresponding to
1 is provided. The guide groove 61 is provided at its innermost portion with a semicircular positioning groove 62 concentric with the shaft hole 46 and having substantially the same diameter as the disk 50. The edge 60a of the storage recess 60 is formed as a slope 60a that gradually opens outward, so that the sprocket 45 can be easily inserted into the storage recess 60.

Next, the sprocket 45 is inserted into the storage recess 6.
0, and the tip fitting portion 4 of the sprocket shaft portion 44
An assembling operation of inserting the 4a into the shaft hole 46 of the sprocket 45 will be described. First, as shown in FIG. 6, the sprocket 45 is inserted into the storage recess 60. In this insertion, the inclined surface 60a serves as a guide, so that the sprocket 45 can be easily inserted into the concave portion 60. In the recess 60, the disc 50 is positioned by the positioning groove 62, so that the shaft hole 65 of the bearing 40 e of the shutter base 30 matches the shaft hole 46 of the sprocket 45. In this state, when the sprocket shaft 44 is inserted into the shaft hole 65 and the sprocket 45 is rotated, the tip fitting portion 44a of the sprocket shaft 44 and the shaft hole 4 of the sprocket 45 are rotated.
6, the tip fitting portion 44 a is easily inserted into the shaft hole 46. At this time, as shown in FIG. 7, the inclined surface 52 of the shaft hole 46 and the inclined surface 47 of the distal end fitting portion 44a serve as guides for insertion. Therefore, even if the sprocket shaft 44 is inserted into the shaft hole 46 in a state where the core is displaced, the distal end fitting portion 44a moves while being guided by the inclined surface 52, so that the distal end does not hit the step surface 54, and the inserted portion is inserted. Is easily performed.

The operation of the thus-configured film unit with lens will be described. When the shutter button 16 is pressed, the locking lever 41 is pressed in conjunction with this, as shown in FIG. Thereby, the locking lever 4
The shutter drive lever 39a disengaged by the movement of the shutter drive lever 39 is rotated counterclockwise from the initial position by the spring 40. The pressing surface 39b is engaged with the claw portion 34a and presses the claw portion 34a, thereby instantaneously rotating the shutter blade 34. As a result, the claw portion 34a is pressed rightward, so that the shutter blade 34 is rotated clockwise, and the exposure opening 28 is opened. Thereafter, when the shutter blade 34 is further rotated clockwise, the pressing surface 39b is released from engagement with the claw portion 34a. When this engagement is released, the shutter blade 34 is rotated counterclockwise by the spring 33, and returns to the position where the exposure opening 28 is closed, thereby completing the photographing. The shutter drive lever 39a is connected to the cam arm 3
When 9c contacts the cam 43, its rotation is stopped.

After the photographing is completed, when the winding knob 18 is rotated and the film 23 is wound around the cartridge, the driven sprocket 45 is rotated counterclockwise through the perforation 23a. As a result, the cam 43 is
The shutter drive lever 39a is rotated counterclockwise against the urging of 0, and the shutter drive lever 39a is rotated clockwise. During this rotation, when the shutter drive lever 39a comes into contact with the claw portion 34a, it is deformed upward and gets over it. Then, when the shutter drive lever 39a returns to the initial position and the shutter is charged, the preparation for the next photographing is completed.

In the above-described embodiment, the present invention is applied to the fitting structure of the sprocket 45 of the film unit with the lens and the sprocket shaft 44 inserted therein. When inserting a male fitting member such as a shaft into the inside, it is necessary to position the dividing surface of the molding die on the slope of the hole or recess due to restrictions such as the direction in which the molded part and the molding die are removed. In any case, the present invention can be applied. Further, the shaft hole is not limited to a square hole and may be a round hole.

[0023]

As described above, according to the present invention,
Formed to taper to the tip of the sprocket shaft,
Plan for fitting sprocket shaft to the sprocket body
Fitting of a first slope serving as an inner surface with the sprocket body
The opening edges at both ends of the hole gradually widen toward the outside.
The sprocket shaft is formed so that
Since the inner slope and the second slope are provided, there is no center between both parts.
Even if this occurs, the insertion guide is not
It is done reliably. Moreover, the second slope is provided at both ends of the fitting hole.
The sprocket body is inserted in only one direction.
The degree of freedom of automatic assembly
And automatic assembly is simplified. Also, one of the second slopes
Cut off the intersection between the second slope and the fitting hole
Is provided, and the step surface of this step is
Used as the mold division surface during injection molding of the rocket body, and at the step
The length of the step surface corresponding to the second slope in the first
Is set shorter than the length of the slope of
The mold parting surface may be an obstacle when inserting the sprocket shaft
The sprocket shaft can be securely fitted into the fitting hole
it can.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a main part of a fitting structure of a sprocket and a sprocket shaft embodying the present invention.

FIG. 2 is a sectional view showing a state where a sprocket shaft is inserted into a conventional sprocket.

FIG. 3 is a perspective view illustrating an appearance of a film unit with a lens.

FIG. 4 is an exploded perspective view showing a unit main body.

FIG. 5 is an exploded perspective view showing a shutter unit.

FIG. 6 is a perspective view showing a state where the sprocket is incorporated in the sprocket housing recess.

FIG. 7 is a sectional view showing a state where a sprocket shaft is inserted into the sprocket of the present invention.

[Explanation of symbols]

 44 Sprocket shaft 44a Tip fitting part 45 Follower sprocket 46, 65 Shaft hole 47, 51, 52 Slope 50 Disk 60 Sprocket storage recess 61 Guide groove 62 Positioning groove

Claims (1)

(57) [Claims] 1. A sprocket shaft and the sprocket shaft
The fitting hole into which the
Claws that engage with Lum perforation
Or a sprocket body composed of injection molded products
Film follower for film unit with lens
In a proket, the tip of the sprocket shaft is formed so as to be tapered.
When the sprocket shaft is fitted to the sprocket body
And a first inclined surface serving as a guide surface of the sprocket body and opening edges at both ends of the fitting hole of the sprocket body.
It is formed so as to gradually spread as it goes toward the
A second slope that serves as a guide surface when the sprocket shaft is fitted, and a second slope formed on one of the second slopes and a fitting hole;
The fitting hole is formed so as to cut off the intersection with the surface.
Having a step surface intersecting the center line of the step, and a length corresponding to a second slope of the step surface in the step portion
Is set shorter than the length of the first inclined surface, and the step surface is divided into molds at the time of injection molding of the sprocket body.
Film unit with lens
Film driven sprocket.