JPS59812B2 - camera - Google Patents

Description

[Detailed description of the invention] The present invention relates to a multiple exposure device for a camera.

The conventional multiple exposure method is to press the rewind button after the first shot to rewind the film one frame, and then use the winding lever to charge the shutter and wind the film for the second exposure. However, in addition to being complicated to operate, it was also extremely difficult to rewind the sprocket accurately.Also, a clutch was installed between the sprocket gear and the sprocket to prevent the sprocket shaft from being pushed. A mechanism has been proposed in which the shutter charging and film winding are disconnected by disengaging the clutch by raising the lever, so that only the shutter charging can be performed using the winding lever.

Even in such a multiple exposure device, the sprocket and spool rotate slightly during the second winding due to friction between the sprocket gear and the sprocket, and friction between the spool shaft and the spool. If the film moves even slightly, the image of the subject will be misplaced on the film. For example, when thin graduation lines are imprinted on the film as in multiple exposures in cilloscope photography, it becomes very unsightly if the graduation lines are imprinted with slight deviations. In order to prevent such film movement, the clutch between the sprocket gear and the sprocket is released by pushing up the sprocket shaft, and the sprocket shaft rotates together with the sprocket gear when charging the shutter for multiple exposures. It is known that a sprocket is provided with a friction member, and when the sprocket shaft is pushed up, the friction member is pressed against a fixed part of the camera via a spring.

In such a configuration, a frictional force due to the above-mentioned spring is generated between the sprocket shaft and the sprocket, and there is a risk that the sprocket may move slightly as the sprocket shaft rotates. In order to prevent the film from moving during shutter charging for multiple exposures, the present invention employs a system in which the sprocket shaft for engaging and disengaging the clutch rotates together with the sprocket to disengage the clutch. In a camera in which the sprocket shaft can be locked in its disengaged position, a friction member is fixed to the sprocket shaft and a blocking member is provided that interlocks with the sprocket shaft so that when the sprocket shaft is pushed up, the friction member locks in the camera. The rotation of the sprocket is restrained by pressing against the fixed part of the sprocket, and the rotation of the spool is also prevented by the blocking member, thereby locking the sprocket shaft in that state.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view showing the main parts of an embodiment of the present invention, in which 1 is a winding lever, 2 is a winding shaft that reciprocates together with the lever, and a gear 7 is connected to the lower part via a one-way clutch 8. The movement of the lever 1 in the winding direction is transmitted to the spool 13 and sprocket 15 via gears 9, 10, and 11, and is also transmitted via gear 12 meshing with gear 11 to the shutter charge mechanism. The spool 13 is connected to the gear 1 via a spring 14.
0, and a sprocket shaft 16 is fitted into the sprocket 15 so as to be able to slide in the axial direction through a pin 17 and a long groove 15a, and to rotate integrally. A clutch pawl 11a that is rotatably fitted around the circumference and provided at the tip engages with a pin 16a implanted in the sprocket shaft, and the rotation of the gear 11 is caused by the clutch pawl 1.
1a, pin 16a, shaft 16, pin 17, and long groove 15a. Sprocket shaft 16
A rewind button R is provided at the lower end of the rewind button R, which is pushed upward against the spring 230 so that the shoulder 16d of the shaft engages the locking lever 19.
At the position where the pin 16a is engaged with the clutch pawl 11a, the sprocket becomes free from the drive system. In this position, the normal case of rewinding takes place. The cam plate 23 provided at the lower end of the winding shaft 2 engages the locking lever 19 at the final position of the winding lever operation, and rotates the lever 19 against the spring to release the lock of the sprocket shaft. It's becoming like that. Reference numeral 3 denotes a film counter drive cam fixedly attached to the winding shaft 2. As is well known, a lever 4 having a feed pawl 4'' is swung to move a counter scale plate 5 (shown integrally with a ratchet plate). advance.

6 is a retaining claw.

The bent arm 4a of the lever 4 has one end connected to the -S22 of the interlocking lever 22, which is in contact with the conical portion 16b at the tip of the sprocket shaft.
The other arm of the interlocking lever 22 is provided at its tip with a blocking pawl 22a that can engage with a ratchet 13a provided on the spool 13. When performing multiple photography, after the first exposure, the rewind button R is pushed up beyond the rewind position, and the shoulder 16c of the shaft 16 is engaged with the locking lever.

At this time, the clutch is released and the sprocket becomes free, and the friction plate 20 fixed to the shaft 16 is pressed against a stop plate 21 provided on the camera fixing part, so that rotation is restrained. Further, the conical portion 16b at the tip of the shaft 16 is connected to the interlocking lever 22.
is rotated against the spring, and the blocking claw 22a at the end of the arm bites into the ratchet part 13a of the spool 13 to prevent the spool from rotating, and the counter feed lever 4 is rotated by the other arm 22b. Rotate the pawl 47 to separate it from the ratchet plate 5. When the winding lever is rotated in this state, the sprocket is separated from the winding gear train by the clutch and is restrained by the friction plate, and the spool is prevented from rotating by the blocking pawl 22a. The shutter 1 is charged without moving at all, and the film counter 1 does not operate at all at this time.At the shutter charge completion position, the cam plate 23 at the lower end of the winding shaft pushes the locking lever 19 and locks the sprocket shaft 16. is released, the shaft 16 returns to its old position by the force of the spring 230, and the sprocket
The restraint on the spool is released, and the film counter claw returns to the position where it engages with the ratchet teeth again.

In this embodiment, a single rewind button is used for both rewinding and multiple exposure preparation, and a winding lever is also used to release the sprocket shaft. The embodiment shown in FIG. 3 is constructed so that the sprocket shaft can be unlocked in conjunction with the operation of the shutter release or shutter shutter. In FIG. 2, reference numeral 24 denotes an operating knob provided on the outside of the camera. When the knob is turned in the direction of the arrow, a cam 25 fixed coaxially with the knob rotates, pushing the friction plate 20 upwards, as shown in FIG. 1. Preparations for multiplex imaging are performed in the same manner as in the embodiment.
At this time, the hook portion 26a of the locking lever 26 is pulled by the spring and engages with the tip 25a of the cam 25 to lock the sprocket shaft. A shutter release rod 27 has an arm 27a to be engaged with the arm 26b of the locking lever 26, and rotates the locking lever 26 in conjunction with the shutter release operation to release the locking of the cam 25.

The cam 25 is rotated clockwise by the force of the spring 25b to restore its original position and release the sprocket shaft. FIG. 3 shows an embodiment in which the locking lever 26 is released in conjunction with the movement of the shutter shutter, in which 28 is the trailing brake arm of the focal plane shutter, and 29 is a brake spring. In the same way as in the previous embodiment, the sprocket shaft 16 is pushed up by the cam 25 and locked by the locking lever 26, and then the shutter 1 is charged by the wind-up lever and the release button is pressed to release the shutter 1. When activated, the leading curtain and the trailing curtain run, and at the end of the running of the trailing curtain, a member interlocking with the trailing curtain shaft engages the brake arm 28 and rotates it in the direction of the arrow. The rear curtain is braked by friction with the leaf spring 29. At this time, the pin 28a provided on the brake arm engages with the lower part of the locking lever 26 and rotates the lever clockwise to release the lock of the cam 25 and restore the sprocket shaft 16, allowing the next normal shooting. enable. The present invention is configured as described above, and when the sprocket gear rotates for shutter charge for multiple exposures, the sprocket receives only a slight rotational friction at the fitting part with the gear, so that the sprocket shaft can be rotated easily. If the film is locked by the locking member, rotation will be prevented by the friction between the friction plate and the camera fixing part, and the spool will also be prevented from rotating by the blocking member, so the film will not move. Good images can be obtained without any fear.

Also, in terms of operation, there is no need to charge the shutter while continuing to press the sprocket shaft as in the conventional case, and an easy-to-operate multiple exposure device can be obtained.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention, FIG.
The figures are perspective views showing other partially modified embodiments. 1: Winding lever, 2: Winding shaft, 3: Film counter drive cam, 4: Feed pawl, 5: Scale plate, 7: Gear, 8: One-way clutch, 11: Sprocket gear, 11a:
Clutch pawl, 13: Spool, 15: Sprocket, 1
6: sprocket shaft, 19: locking lever, 20: friction plate, 21: stop plate, 22: interlocking lever, 22a: blocking claw,
23: Cam plate, 24: Operation knob, 25: Cam, 26: Locking lever, 27: Release rod, 28: Brake arm, 29
:Brake spring.

Claims (1)

[Claims] 1. A clutch is provided between a sprocket and a gear that drives the sprocket, and the clutch is disengaged by axial movement of a sprocket shaft that rotates with the sprocket, and the sprocket shaft is locked at the disengaged position by a locking member. In the camera, a friction member is fixed to the sprocket shaft, and a blocking member is provided that moves in conjunction with the movement of the sprocket shaft, and the friction member is fixed to the camera fixing portion while the sprocket shaft is locked at the detached position. A multiple exposure device for a camera, characterized in that the rotation of the sprocket is restrained by pressing the sprocket, and the rotation of the spool is prevented by the blocking member.