JPS622600Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a film winding mechanism for a still camera.

In the film winding mechanism of still cameras,
A reverse movement prevention mechanism is provided to prevent the winding lever and winding shaft from returning to their initial positions during film winding. This reverse movement prevention mechanism releases the reverse movement prevention after winding is completed and allows the winding lever and the winding shaft to return to their initial positions. On the other hand, the film feed gear is also provided with another reverse rotation prevention mechanism.
This reverse rotation prevention mechanism consists of a film feed gear engaging pawl and a reverse rotation prevention lever, and the engagement between the two prevents reverse rotation. The engagement between the reversal prevention lever and the engagement pawl is performed immediately before the aforementioned reverse movement prevention mechanism is released.

Conventionally, in order to ensure the sequence of the engagement of the engagement pawl and the reverse rotation prevention lever, the completion of winding, and the release of the reverse motion prevention mechanism, a slight margin was provided between each timing. After the hoisting operation was completed, this margin remained as a gap between the anti-reverse lever and the engaging pawl. This gap is usually not a problem, but when a highly stretchable film is loaded into the camera, the film may shrink after the film is wound, causing the film winding mechanism to reverse itself by the amount of the gap mentioned above. . As a result, there are disadvantages such as the screen spacing of the film becoming irregular and the adjustment of each timing having to be done in parallel, which requires skill.

The object of the present invention is to provide a film winding mechanism in which the above-mentioned gaps are small and each of the above-mentioned timings can be easily adjusted.

FIGS. 1 and 2 show a conventional example. FIG. 1 is an exploded view showing an example of a film winding mechanism.

In FIG. 1, a hoisting plate 4 is integrally fixed to a rotating shaft 2a that is integrally engaged with the hoisting lever 2 and serves as the center of rotation of the hoisting lever. This hoisting lever 2 is moved by an arrow A in the figure by a spring (not shown).
It is urged in the direction of , and always tries to return to its initial position.
On the other hand, the shaft portion 6a of the winding shaft 6 has an oval cross section.
The oval hole 8c of the winding regulation plate 8 fits therein. The reverse movement prevention plate 10 on the winding regulation plate 8 is formed with an adjustment slot 10a and a circular hole 10b for adjustment to be described later. In this reverse movement prevention plate 10, the circular hole 10b fits with the hoisting shaft 6, and the adjustment elongated hole 10a fits into the hoisting regulating plate 8.
The pin 8d is fitted onto the pin 8d. The reverse movement prevention plate 10 is clamped and tightened by a stepped portion formed on the pin 8d and a screw 12 that fits into a threaded portion formed inside the pin 8d. Rotates integrally with the upper regulation plate.

As mentioned above, the reverse movement prevention plate 10, the screw 12, and the hoisting regulation plate 8, which are integrally connected to the hoisting shaft 6,
A spring (not shown) always applies a biasing force in the direction opposite to the arrow B, and it tries to return to the initial position. screw 12
When the hoisting lever 2 is operated for hoisting, the head 12a is pushed by the hoisting plate 4 and rotates in the direction of arrow B in the figure. This rotation is transmitted to the hoisting shaft 6 via the reverse movement prevention plate 10 and the hoisting regulating plate 8.
When the reverse motion prevention plate 10 starts to rotate, a ratchet tooth portion 10c formed at a predetermined angle at its tip engages with a reverse motion prevention pawl 14 swingably provided on the camera body. However, the hoisting lever 2 is prevented from returning to the initial position by the above-mentioned spring. After the winding mechanism has completed charging and winding one frame of film, the ratchet teeth 10c are disengaged from the reverse movement prevention pawl 14, and the reverse movement prevention pawl 14 is activated by a spring (not shown). Since it rotates and is arrested to a position where the reverse movement of the ratchet tooth portion 10c is not prevented, the hoisting lever 2 and the hoisting shaft 6 are allowed to return to their initial positions. The hoisting regulating plate 8 is composed of regulating surfaces 8a and 8b, and the regulating surface 8a allows the hoisting lever 2 to further rotate in the direction of arrow B after the backlash prevention plate 10 and the backlash prevention pawl 14 are disengaged. When operated, it comes into contact with a pin 16 fixed to the camera body to prevent the winding lever 2 and the winding shaft 6 from rotating any further. The regulating surface 8b comes into contact with a pin fixed to the camera body (not shown) and determines the position when the winding lever 2 and the winding shaft 6 return to their initial positions.

The adjustment elongated hole 10a of the back movement prevention plate 10 is formed to adjust the relative position of the back movement prevention plate 10 and the hoisting restriction plate 8, and the connection position of the adjustment elongated hole 10a and the screw 12 is adjusted. By changing the position, the relative positioning of the reverse movement prevention plate 10 and the winding shaft 6 changes, so the timing of disengagement of the reverse movement prevention and the timing of winding, film winding and winding regulation can be adjusted. be able to.

A charge plate 18 is fixed to the lower end of the winding shaft 6. A film feed gear 20 is rotatably provided on the winding shaft 6 above the charge plate 18. An engaging member 28 having three engaging claws 22, 24, and 26 is provided on the back surface of the film feed gear 20.
is permanently installed. Engagement claw 2 of this engagement member 28
2, 24, 26, the shaft 3 is placed on the charge plate 18.
It engages with a film feed pawl 32 rotatably supported by a screw. The film feed claw 32 is biased by a spring (not shown) so that its tip 32a always comes into contact with the engaging member 28, and when the charge plate 18 rotates in the winding direction, that is, in the direction of arrow B. are the engaging claws 22, 2 of the engaging member 28.
4 and 26 to transmit rotation to the film feed gear 20, and when the charge plate 18 rotates in the opposite direction, it slides on the edge of the engaging member 28 and does not transmit rotation. In this way, the film feed claw 32
Due to the engagement and sliding of the engaging member 28, only rotation in the winding direction, that is, in the direction of arrow B, is always transmitted to the film feed gear 20. The rotation of the film feed gear 20 is transmitted to an idle gear A36 meshing with the film feed gear 20, and further to an idle gear B38 coaxially connected to the idle gear A36. The rotation of idle gear B38 is transmitted to sprocket gear 40 to rotate sprocket 44 on the one hand, and is transmitted to spool gear 46 via idle gear C42 to rotate spool 48 on the other hand.

Note that the charge plate 18 has a charge lever 5.
0 is rotatably provided with respect to the charge plate 18, and as the charge plate 18 rotates, the charge lever 50 is pulled, thereby accumulating the drive source of the shutter mechanism and the mirror drive device (not shown).

The reversal prevention lever 53 is connected to the film feed gear 20
It is rotatably supported by a shaft 55 fixed to the camera body near the camera body, and is biased by a spring 56 so that its tip 58 always comes into contact with the edge of the engaging member 28 of the film feed gear 20. The engaging claw 2
2, 24, and 26 to prevent the film feed gear 20 from rotating in reverse.

FIG. 2 shows a conventional mechanism, and is a bottom view showing the film feed claw 32, the film feed gear 20 and its engaging member 28, and the reverse rotation prevention lever 53. Engagement claws 22, 24, 26 of engagement member 28
has a steeply sloped abdomen 22a, 24a, 26a and a gently sloped back part 22b, 24b, 26b. In Figures 1 and 2, the hoisting lever 2
When the film is wound up, the charge plate 18 rotates through the winding shaft 6, and the film feed claw 3 rotates accordingly.
2 rotates clockwise in FIG. 2 from the initial position drawn by the solid line to the position drawn by the two-dot chain line. During this time, the film feeding claw 32 is moved, for example, to the engaging claw 22.
The engaging claw 22 is engaged with the abdomen 22a of the engaging claw 24.
Rotate it to the position. The film feed claw 32 is
Since it rotates integrally with the winding shaft 6, reverse movement is prevented during the winding movement by engagement with the reverse movement prevention pawl 14 of the reverse movement prevention plate 10 at the upper end of the winding shaft 6. Ru. After winding and winding of the film are completed, the film feed claw 32 is disengaged from the back motion prevention claw 14 of the back motion prevention plate 10 and is allowed to return to the initial position. Return to the position drawn by the solid line. At this time, film feed claw 3
The tip 32a of the engagement claw 22 slides on the back 22b of the engagement claw 22. Further, the above-mentioned winding-up regulating plate 8 prevents rotation beyond the position indicated by the two-dot chain line. Due to the above-described action, the film feed gear 20 rotates one-third of a rotation, and this rotation is transmitted to the sprocket 40 and the spool 48 to wind up one frame of film.

The tip 59 of the reversal prevention lever 53 is rotated while the film feed gear 20 is rotating during winding.
It slides on the back part 24b of the engaging claw 24 and climbs a gentle slope, and rotates counterclockwise against the force of the spring 57. Then, before the winding is completed and just before the reverse movement prevention plate 10 is disengaged from the reverse movement prevention pawl 14, the spring 57 is inserted so that the tip 59 enters the portion facing the abdomen 24a of the engagement pawl 24. Rotates clockwise by . After this, the engaging claw 24 further
Since it rotates a little, when winding is completed, the tip 59 of the anti-reverse lever 53 and the abdomen 24 of the engaging claw 24
A small gap will be created between the

Normally, even if there is such a gap, the film feed gear 20 will not move unexpectedly due to the presence of friction within the film winding mechanism, and the film screen interval will remain constant for normal shooting. can. However, when a highly stretchable film is loaded into the camera, the film is stretched and stretched during winding, and after being wound around the spool 48, it contracts and acts to reverse the spool 48. When the shrinking force of the film is stronger than the frictional force within the film winding mechanism described above, the reverse rotation of the spool 48 is transmitted to the film feed gear 20 via the spool gear 46, idle gear C42, idle gear B38, and idle gear A36. The amount of reversal corresponds to the amount until the tip 59 of the reversal prevention lever 53 comes into contact with the abdomen 24a of the engagement claw 24, that is, the amount of the above-mentioned gap. As a result, when a highly stretchable film is used, there is a risk that the screen spacing of the film may become uneven. In order to improve these defects, the gap should be made smaller, but the reason for providing the gap is as follows, and it has not been possible to make the gap that small. In other words, the timing before the winding is completed is Γ when the tip 59 of the reverse prevention lever 53 engages the engagement claw 2.
4 (at the time of actuation of the reverse prevention lever), Γ winding and film winding are completed (at the time of winding completion), Γ contact with the reverse motion prevention pawl 14 of the reverse motion prevention plate 10. The engagement must be disengaged and the hoisting mechanism is allowed to return to the initial position (at the end of reverse movement prevention), and the hoisting regulating plate 8 comes into contact with the pin 16 (at the time of maximum angle hoisting). There is. The gap is
This is the winding angle between the time when the anti-reverse lever is actuated and the maximum angle winding time. During this time, the timing of the winding completion time and the reverse motion prevention end time must be determined, and their order must not be reversed. Therefore, if safety is considered, a margin is required between each time point, and a gap is therefore required.

Conventionally, in order to adjust the amount of such a gap, the anti-reverse lever 53 has an eccentric structure so that the position of the center of rotation can be changed, and the position of the tip 59 facing the engagement member 28 is adjusted. However, this adjustment had to be made in conjunction with the adjustment of the back movement prevention plate mentioned above, which was delicate and difficult.

As mentioned above, the present invention aims to eliminate these drawbacks.

An embodiment of the present invention will be described below with reference to FIGS. 1, 3, and 4.

3 and 4 show the film feed claw 32,
5 is a bottom view showing the film feed gear 20, its engaging member 28, and the reverse rotation prevention lever 52. FIG. In the figure, the distal end portion 58 of the reverse prevention lever 52 is provided with a stepped portion (first step portion) 58a and an inclined portion (second step portion) 58b.
b is inclined so that the difference in level from the stepped portion 58a becomes smaller as the tip approaches the tip.

The entire structure of the film winding mechanism is the same as that shown in FIG.

As in FIG. 2, when the film feed pawl 20 is wound, it rotates from the position drawn by the solid line to the position drawn by the two-dot chain line, and during this period, the film feed pawl 20 engages with the engaging member 28 of the film feed gear 20. When engaged, the film feed gear 20 is rotated approximately one-third of a turn.

The timing from before the winding mechanism completes winding is set as follows. That is, in the middle of winding Γ, the reverse movement prevention plate 10 engages with the reverse movement prevention pawl 14, and the reverse movement of the winding mechanism is prevented.

Γ As shown in FIG. 4, the anti-reverse lever 52 rotates clockwise so that the first step 58a of the step-like step of the tip 58 of the anti-reverse lever 52 faces the abdomen 24a of the engagement claw 24 ( (at the time of the first activation of the anti-reverse lever).

Γ Winding and film winding are completed (at the time of completion of winding) Γ The back movement prevention plate 10 is disengaged from the back movement prevention pawl 14 and the winding mechanism is allowed to return to the initial position (back movement prevention (at the end), Γ As shown in FIG.
The anti-reverse lever 52 further rotates clockwise so as to come into contact with the abdomen 24a of the anti-reverse lever 52 (at the time of second activation of the anti-reverse lever). The hoisting regulation plate 8 contacts the pin 16 (at the time of maximum angle hoisting) Take the timing in this order.

As mentioned above, the tip 58 of the anti-reverse lever 52
When a step-like stepped portion is formed, the first step portion 58a
From the time when the reverse prevention lever 52 engages with the engagement pawl 22, reversal prevention is ensured, and moreover, the gap between the reverse prevention lever 52 and the engagement pawl 24 at the time of maximum angle winding is equal to that of the second reversal prevention lever. This is the angle that can be hoisted from the time of activation to the time of maximum angle hoisting, which is much smaller than conventional methods.

It goes without saying that the same effect can be obtained even if the stepped portion as described above is formed on the engaging claw side.

Furthermore, if a tapered slope portion 58b is formed at the tip portion 58 of the reverse prevention lever 52, the tip portion 58
As it rotates clockwise in the figure and engages deeply with the engaging pawl 24, the inclined portion 58b approaches the tip of the engaging pawl, and finally the tip of the engaging pawl 24 comes into contact with the inclined portion 58b, so that the maximum There is no gap between the anti-reverse lever 52 and the engaging pawl 24 at the time of angle winding.

The film winding mechanism of the present invention includes a winding shaft that rotates when a winding operation is performed, a reverse movement prevention plate that rotates integrally with the winding shaft, and a film winding mechanism that engages with the reverse movement prevention plate. Prevents reverse movement of the hoisting shaft until the shaft rotates a predetermined angle,
A reverse motion prevention pawl that detaches from the reverse motion prevention plate and allows the hoisting shaft to return to its initial position after being rotated by a predetermined angle, a charge plate fixed to the hoisting shaft, and a swingably provided on the charge plate. a film feeding gear comprising a film feeding pawl and an engaging member that engages with the film feeding pawl, transmitting rotation of the film feeding pawl to a sprocket and a spool; and a film feeding gear that engages with the engaging member of the film feeding gear. A step-like step is formed on at least one of the engaging parts of the reversing prevention lever and the engaging member of the film feed gear, and a reversing prevention plate and a reversing prevention lever are formed. Before the anti-reverse movement lever disengages from the prevention pawl, the engagement member is engaged with the engagement member at the first step, and after the anti-reversal plate and the anti-reversal pawl are disengaged, the anti-reversal lever is removed. The engagement member is characterized in that the engagement member is engaged with the engagement member at the second step portion.

According to the present invention, the reversal prevention lever and the engagement pawl are reliably engaged at the first stage portion before the reversal prevention plate and the reversal prevention pawl disengage, thereby ensuring prevention of reversal. The final gap between the anti-reverse lever and the engaging pawl is between the second step portion and the engaging pawl, so it can be very small. As a result, the flow of the winding mechanism can be reduced, so that the backlash of the film that occurs when winding a highly stretchable film can be reduced, and the screen spacing of the film can be made uniform. Moreover, the gap adjustment between the reversal prevention lever and the engaging pawl is not so dependent on the timing at which the reversal prevention mechanism is released, as the first stage of the stepped portion engages the engaging pawl sooner. It's easy.

Furthermore, if a step-like step is provided at the tip of the reverse prevention lever, and a tapered slope is formed at the second step of the step, the slope increases as the tip engages deeply with the engagement pawl. Since it protrudes toward the tip of the engaging pawl, the inclined portion and the engaging pawl come into contact with each other, eliminating the gap between the reverse prevention lever and the engaging pawl. This eliminates the flow of the winding mechanism and eliminates the need to adjust the gap.

[Brief explanation of the drawing]

1 and 2 show a conventional example, with FIG. 1 being an exploded perspective view and FIG. 2 being a bottom view of the main parts. 3 and 4 are bottom views showing essential parts of an embodiment of the present invention. 6...Hoisting shaft, 8...Hoisting regulation plate, 10...Reverse movement prevention plate, 14...Reverse movement prevention pawl, 18...Charge plate, 20...Film feed gear, 22, 24,
26... Engaging claw, 28... Engaging member, 44... Sprocket, 48... Spool, 52, 53...
Reverse prevention lever, 56, 57... Spring, 58, 5
9... Reverse prevention lever tip, 22a, 24a,
26a...Engaging portion of the engagement claw, 58...Engaging portion of the reverse rotation prevention lever, 58a...First step portion, 58b...
Inclined part (second stage part).

Claims (1)

[Claims for Utility Model Registration] 1. A hoisting lever, a hoisting shaft that rotates when the hoisting lever is hoisted, and a reverse movement prevention plate that rotates integrally with the hoisting shaft; The hoisting shaft is engaged with the reverse movement prevention plate to prevent reverse movement of the hoisting shaft until the hoisting shaft rotates through a predetermined rotational angle, and after rotating through the predetermined rotational angle, the hoisting shaft is detached from the reverse movement prevention plate and the hoisting shaft is a reverse movement prevention pawl that allows the film to return to its initial position, a charge plate fixed to the winding shaft, a film feed pawl swingably provided to the charge plate, and a film feed pawl that engages with the film feed pawl. a film feeding gear comprising a plurality of engaging pawls for transmitting rotation of the film feeding pawl to a sprocket and a spool; and a reversal prevention lever that engages with the engaging pawl of the film feeding gear to prevent the film feeding gear from reversing. In the film winding mechanism, a first stage part and a first stage part are arranged on one of the mutually engaging parts of the reversal prevention lever and the engaging claw of the film feed gear in order from the tip of the engaging part. A second step portion is formed that protrudes toward the other engaging portion side than the first and second step portions, and the first and second step portions are arranged so that the back movement prevention plate and the back movement prevention pawl are disengaged from each other. After the first step portion engages with the other engaging portion and the back movement prevention plate and the back movement prevention pawl are disengaged, the second step portion engages with the other engaging portion. A film winding mechanism characterized in that the film winding mechanism is arranged so as to 2. The first and second step portions are provided on the reversal prevention lever, and the second step portion becomes closer to the other engaging portion as the distance from the first step portion increases with respect to the engaging portion of the engaging claw of the film feed gear. The film winding mechanism according to claim 1, characterized in that the film winding mechanism is a sloping portion that is formed so as to protrude.