JPH0410575Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a mechanism for preventing malfunction of a synchro contact in a camera shutter.

[Background of the idea]

A spring that charges the force of the shutter operation, a set plate that controls the closing operation of the shutter by the spring, a set plate claw disposed on the set plate and given rotation by the spring, and a final set plate of the set plate. A judgment lever that locks the setting plate pawl until it reaches the operating range, and a synchronizing contact consisting of two contact pieces, one of which is pushed by the setting plate pawl and contacts the other contact piece. A camera shutter configured to turn on a synchronization contact is already known.

Synchronous contacts with this structure do not require a separate elastic material because one of the two contact pieces, which is activated by the pressure of the set plate pawl, opposes the set plate pawl due to its own rigidity. This has the advantage of reducing component parts and assembly man-hours.

In such a case, the only ability to prevent the synchro contact from being turned ON inadvertently when the shutter is not charged relies solely on the rigidity of the synchro contact piece. However, as cameras have become more compact, the space between the two synchronizer contact pieces has become very narrow, and as a result, when receiving an external shot, the difference in mass with the set plate pawl causes the synchronizer contact to become smaller. The rigidity of the piece could not prevent it from swinging, causing the inconvenience of the contact being turned on inadvertently.

In order to prevent this inconvenience, increasing the rigidity of the synchro contact piece resulted in the inconvenience of slowing down the operation of the set plate.

[Purpose of invention]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a synchro contact malfunction prevention mechanism that eliminates the above-mentioned conventional disadvantages and has improved shock resistance without increasing the number of component parts.

[Summary of the idea]

The above object of the present invention is achieved by extending one arm of the judgment lever provided on the setting plate and bringing it into contact with the setting plate pawl to stop the operation. explain.

[Example of idea]

FIG. 1 is a view showing the main parts of a camera shutter according to an embodiment of the present invention, showing the shutter charging, and FIG. 2 showing the state after the shutter has been released.

1 is a set plate (shutter closing control member);
The spring 1a imparts rightward movement, and the axis 1b
and the groove 1c so as to be movable in a straight line.

A determination lever 2 is supported by a shaft 2a provided on the set plate 1, is given dextrorotation by a spring 2b, and has a locking portion 2c, an arm 2d, and a bending portion 2e.

Reference numeral 3 denotes a set plate pawl, which is rotatably supported by a shaft 3a placed on the set plate, and is supported by a spring 3b.
During shutter charging, the bend 3e is locked in the dextrorotation direction by the end face of the set plate 1, and the convex portion 3c is
It is engaged with the locking portion 2c of the determination lever 2, and is restrained in the left rotation direction.

Reference numeral 4 denotes a synchro contact piece A, which is supported by another member (not shown) and has rigidity, the strength of which is equal to that of the spring 3.
The tip 4a is set to be stronger than the spring b and weaker than the spring 1a, and the tip 4a is set to be stronger than the spring 1a.
It is made of resin so that it can easily come into contact with the

Reference numeral 5 denotes a synchro contact piece B, which is supported by another member (not shown), and when it comes into contact with the synchro contact piece A4, the contact closes and turns ON.

Reference numeral 6 denotes a main plate, on which the above-mentioned parts and other shutter components (not shown) are mounted.

Next, the operation will be explained.

FIG. 1 shows the shutter already charged.

Although the explanation of the shutter release and release operation is omitted, when the shutter is closed and released from this state, the set plate 1 starts moving to the right by the force of the spring 1a and closes the shutter. Do the action to make it happen. At this time, the set plate claw 3 also starts moving to the right at the same time, but the set plate claw bends 3.
Since it is locked by e, it cannot rotate to the right even though the spring 3b provides dextrorotation. If the vehicle continues to run in this state, the edge 3d of the set plate pawl 3 will come into contact with the tip 4a of the synchro contact piece A and continue to press it. Then, the synchro contact piece 4 is distorted downward and welded to the synchro contact piece B, and the contact is turned on and energized.

In FIG. 2, when the bent portion 2e of the determination lever 2 comes into contact with the end surface of the main plate 6 and rotates to the left against the force of the spring 2b, the locking portion 2c is released and the setting plate pawl 3 is moved to the synchro contact. Due to the rigidity of A4 and the arm 2d of the determination lever 2, the end surface 3d is pushed up and rotated to the left. After this, the arm 2d of the judgment lever 2 presses against the end face 3f, and the judgment lever 2 Since the rotation to the right is restricted by the base plate 6, the determination lever 2 does not exert any force to push the synchro contact piece A4.

[Effect of idea]

As can be seen from the above-mentioned embodiments, by implementing the present invention, the synchronization contact can be turned on inadvertently by changing the shape of the judgment lever without increasing the number of parts compared to the conventional one. The effect of preventing this can be obtained.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention in which the shutter is being charged, and FIG. 2 similarly shows a state in which the shutter is not being charged at the end of the shutter operation. 1... Set plate, 2... Judgment lever, 3... Set plate pawl, 4... Synchro contact piece A, 5... Synchro contact piece B, 6... Main plate.

Claims (1)

[Claims for Utility Model Registration] A set of synchronizer contact members, a set plate that operates using a spring as a force source and controls the closing operation of the shutter, and is swingably supported on the set plate,
a set plate pawl that pushes at least one of the synchro contact pieces in front of the final operation region of the set plate; an engaging part that suppresses the swinging of the set plate pawl up to the final operating area of the set plate, an abutment part that abuts an arbitrary fixing member in the final region of operation of the set plate, and a contact part that swings and displaces the set plate pawl due to the corresponding contact. A mechanism for preventing malfunction of a synchro contact, comprising: a determination member that moves to a position to prevent the synchro contact from swinging toward the synchro contact side;