JPS5843727B2 - camera no makitomekikou - Google Patents

Description

[Detailed description of the invention] The present invention relates to a camera winding mechanism.

When winding film in a conventional camera, the sprocket shaft rotates only in the winding direction, and is not rotated in the opposite direction by a ratchet or one clutch, and also uses a friction brake to rotate in the winding direction. It is well known that the film is prevented from advancing too much.

In addition, in cameras with conventional focal plane shutters, an engaging part is provided at the end of the winding mechanism on the shutter shaft linked to the winding mechanism to stop the film. There is considerable play in the rotation of the sprocket.

In such a device, increasing the brake force in order to prevent the film from advancing too far would make winding the film extremely difficult, so the brake force cannot be increased.

Therefore, when winding film in a conventional camera,
The inertia of the winding gear, sprocket, film, etc. cannot be sufficiently eliminated by the brake, so the amount of film feed is unstable, and in extreme cases, the screens may overlap.

Therefore, the present invention proposes a mechanism that can eliminate the former drawback and keep the film screen interval constant.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 are diagrams showing an embodiment of this mechanism, with FIG. 1 showing the state before hoisting, and FIG. 2 showing the moment when hoisting is completed.

Further, FIG. 3 shows the state after the winding is completed, the winding lever is returned to the state before winding, and the shutter is not released.

In the figure, reference numeral 1 denotes a winding shaft (not shown in the figure), but when the winding lever is rotated clockwise, the sprocket 11 rotates in the direction of the hour hand via a ratchet or gear train, and the film 12 is moved to a predetermined position. At the same time, the shutter drive spring is charged by a lever mechanism or the like.

In such a mechanism, it is known that after winding is completed, the winding lever returns to its pre-winding position due to the force of a spring.

In such a mechanism, a cam 2 is provided on the winding shaft 1, and a lever 3 is provided with one end 3a of the cam in contact with the cam.

This lever is rotated clockwise about a shaft 5 by a spring 4.

- A lever 7 sharing the blade axis 5 is provided, and a counterclockwise rotation is applied to the lever 3 by a spring 6.

However, this counterclockwise rotation is regulated by a protrusion 3b provided at the other end of the lever 3.

Also, on the sprocket shaft, the lever 7 is centered around the shaft 5.
An index plate 8 is provided which has an engaging portion that engages with one end 7a of the index plate when the winding is completed when the winding is completed in the clockwise direction.

Further, the lever 14 is rotated clockwise about the shaft 15 by the spring 13, but before the shutter driving spring is loaded, the lever 14 is rotated by the lever 16 as shown in FIG. Movement is regulated.

In this mechanism, as shown in FIG. 1, before winding is performed, the lever 7 and index plate 8 are not engaged, and the sprocket can rotate in the winding direction.

Here, when the winding lever is rotated clockwise, the cam 2 also starts rotating clockwise via the shaft 1, and just before the winding is completed, the cams 2 and 3a come out of contact, and the lever 3 is moved by the spring 4. Rotates clockwise around axis 5.

Further, the lever 7 is also rotated clockwise by the protruding portion 3b, and the engaging portion 7a is brought into pressure contact with a portion of the index plate 8 other than the engaging portion.

Further, the lever 16 releases contact with the shutter drive spring 14 as shown in FIGS. 2 and 3 at the same time as the shutter driving spring is loaded, and the lever 14 is rotated clockwise by the spring 13. However, the lever 1 restricts its rotation.

As the winding progresses further, and at the moment when the winding operation is completed, the index plates 8 and 7a are engaged, and at the same time, the lever 14 is also engaged with the lever T, as shown in FIGS. 2 and 3. do.

Therefore, at the moment when winding is completed, the rotation of the winding member due to inertia can be completely canceled by the engagement between 7a and 8.

After the winding is completed, the cam 2 as well as the winding lever return to the state before winding as described above, but since the lever 7 is engaged with the lever 14, the engagement with the index plate 8 is not made. The state remains as it is.

Next, when the shutter is released and the exposure is completed, the lever 16 returns to the position shown in FIG. 8 and becomes the state shown in FIG. 1, and the next hoisting operation can be performed.

By providing such a mechanism, it is possible to prevent the winding member from winding up more than necessary due to inertia, and it is possible to maintain the screen interval at a constant value.

FIGS. 4, 5 and 6 show other embodiments.

In this case, a known double exposure prevention mechanism, an example of which is shown in the figure, is also used.

FIG. 4 shows the state before hoisting, and FIG. 5 shows the moment when hoisting is completed.

FIG. 6 shows the state in which the hoisting lever is returned to the position before hoisting after the hoisting is completed.

The lever 19 is connected to a hoisting lever, and the pawl 22 is always pressed against the hoisting ratchet 25 by means of a spring 21 around the axis 20 via a shaft 20.

In this mechanism, when the film winding lever is rotated, the lever 19 rotates clockwise, and the gear train 27→29→31→3 is rotated through the pawl 22 that engages with the winding ratchet.
5 and the rotational force is transmitted, causing the sprocket 31 to rotate counterclockwise and sending the film 38 in the winding direction.

- In the crab heavy exposure prevention mechanism, when the winding operation is started, the shaft 41 rotates counterclockwise via the gear train, and the engagement plate 39 and cam 40 also rotate counterclockwise together with it.

Cam 40 also rotates counterclockwise. When the cam 40 begins to rotate, the lever 46 in pressure contact with the cam 40 rotates counterclockwise about the shaft 41 and disengages from the lever 42.

Then, the lever 42 is rotated clockwise about the shaft 43 by the spring 44, and is pressed into contact with the engagement plate 39 at a portion 42-b.

42b and the engagement plate 39 as shown in FIG.
engages with.

While this engagement is in progress, the next hoisting operation cannot be performed.

Furthermore, as the shutter driving spring is loaded at the same time as the film winding operation, the lever 45 is out of contact with the lever 42 as shown in FIGS. 5 and 6.
When the photographing completion signal is received, lever 4 is activated as shown in Fig. 4.
2 in the clockwise direction against the force of the spring 44 and rotate 42b.
and 39 are disengaged to enable the next playing operation.

If such a double exposure prevention mechanism is used to regulate the amount of film feed, as described above, a considerable amount of play will occur in the rotational force transmission mechanism, etc., so that accurate feed amount cannot be expected.

Therefore, a gear 34 that meshes with the gear 31 is provided.

Furthermore, an index plate 32 having at least one engaging portion is attached to the gear 34 via a shaft 33.

In this case, the engaging portion 32a of the indexing plate 32 is connected to the gear 34 so that the indexing plate is in a position where the indexing plate is locked by the locking pin 23 provided on the pawl 22 at the moment when winding is completed. 32
Install.

Therefore, the engagement shown in FIG. 5 is made at the moment when winding is completed, and rotation of the winding member due to inertia can be eliminated.

After the winding is completed, when the winding lever is returned to the state before winding, the lever 19 also returns to the position shown in FIG. 6, and the engagement between 23 and 32a is released. is also disengaged, making it possible to carry out the next hoisting operation.

As is clear from the above explanation, by using the present invention, the rotation due to the inertia of the winding mechanism can be completely eliminated without affecting the winding operation in any way. It is possible to maintain a constant value.

Furthermore, in the present invention, the lever is held in a position where it does not engage with the index plate until just before the winding is completed, so that, for example, the six-toothed sprocket is rotated 4/3 of a turn to feed the film a fixed length. Even when the present invention is applied to a camera that performs the above-mentioned method, it is possible to stop the sprocket every time one frame of film is fed, and the above-mentioned effects can also be achieved.

[Brief explanation of drawings]

FIG. 1 shows the state before hoisting in one embodiment, and FIG. 2 shows the moment when the same mechanism completes hoisting. Further, FIG. 3 shows the mechanism in which the winding lever is returned to the position before winding-L after winding is completed. FIG. 4 shows the state before winding up in another embodiment when a double exposure prevention mechanism as shown in the figure is also used,
FIG. 5 shows the state at the instant of completion of hoisting in the same embodiment,
FIG. 6 shows the same embodiment in which the hoisting lever is returned to the position before hoisting after completion of hoisting. 1 is a winding shaft, 2 is a cam on the shaft 1, 3 is an interlocking lever in contact with the cam 2, 7 is a lever supported in parallel with the lever 3, 8 is an index plate, 11 is a sprocket, 14 is a winding and whisker operation The levers 16 that are interlocked with the levers 16 and 16 are used to lock or release the sprocket winding of the lever 7.

Claims (1)

[Claims] 1. Provided coaxially with the film feeding Sufrocket,
An indexing plate for feeding a fixed film length that rotates in conjunction with the sprocket; a first lever that engages with an indexing groove provided around the indexing plate to inhibit rotation of the sprocket; a first spring that urges the first lever in a direction to release the fitting between the lever and the index groove; and a first spring that engages with the first spring when the first lever is fitted into the index groove of the index plate. By fitting, the first lever is held in the fitting position with the index groove against the biasing force of the first spring, and
a second lever that releases the engagement with the first lever upon completion of the exposure operation; and a second lever that is linked to the winding operation of the camera;
a cam member that returns to the initial position after the completion of the winding operation; and a third lever whose displacement is regulated by the cam member, and whose displacement is enabled by releasing the restriction by the cam member immediately before the completion of the winding operation. and a second spring that presses the third lever against the index plate by biasing the third lever via the third lever.