JPS6141072Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a blade opening/closing device for a program shutter.
In detail, it includes a set-related member that rotates, an opening-and-closing member that rotates back and forth to open and close the shutter blade, a swinging member that can connect the set-related member and the opening-and-closing member, and a member that releases the connection of the swinging member. The present invention relates to a blade opening/closing device configured.

For example, in the above-mentioned blade opening/closing device, when the swinging member connects the opening/closing related member and the setting related member, the opening/closing related member pivots in one direction due to the rotation of the set related member, and the opening/closing related member is connected by the releasing member. In the released state, the opening/closing related member turns in the other direction, and the shutter blade is opened/closed by the reciprocating rotation of the opening/closing related member.

By variously changing the release timing of the connection by the release member, the time required for the opening/closing related member to rotate back and forth is varied, thereby obtaining an appropriate shutter opening/closing time.

By the way, the above-mentioned releasing member is generally an iron piece member controlled by an electromagnet, and is formed with an arm portion that pushes the swinging member to swing it, and is pivotally supported by a fixed shaft.

On the other hand, since the above-mentioned swinging member is pivotally mounted on, for example, the set-related member, its position changes moment by moment as the set-related member turns.

Therefore, in the above-mentioned blade opening/closing device, there has been a problem in setting the shutter opening/closing time.

That is, in the conventional configuration, the action portion pressed against the iron piece member changes its relative position with respect to the iron piece member due to the displacement of the swinging member as the set-related member turns.

Therefore, the distance between the operating part of the swinging member and the arm part of the iron piece member changes moment by moment as the set-related member rotates, and the swinging member is not actually operated after the iron piece member has moved. It is not possible to keep the so-called mechanical delay constant.

Furthermore, as the action point of the iron piece member changes due to the displacement of the action part of the rocking member, the force with which the iron piece member pushes the rocking member changes, and the speed at which the iron piece member swings the rocking member also varies. Similarly, this caused the mechanical delay to be unable to be kept constant.

As is clear from the above, in the conventional blade opening/closing device, the mechanical delay from when the blade closing signal is issued until the blade actually closes varies depending on the degree of opening of the blade. This is not preferable because it causes errors.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a blade opening/closing device for a program shutter that does not cause fluctuations in mechanical delay and can provide accurate shutter opening/closing times.

The purpose of the present invention is to coaxially support the set-related member and the opening/closing-related member, and pivot the swinging member so that the pressing part is located on the previous axis in the connected state. will be achieved.

The present invention will be explained below based on the illustrated embodiments.

FIG. 1 is a plan view showing a shutter blade opening/closing device. In the figure, reference numeral 1 indicates a shutter base plate forming an aperture 1a, but its shape is omitted. 2 is the shutter release plate, with protrusion 2
a, 2b, and 2c, which are disposed so as to be movable in the vertical direction, and are given an upward movement habit by a spring (not shown). 3 is the set board, hook 3a,
A gear 3b is formed, which is rotatably supported by a shaft 4, and is given a dextrorotatory behavior by a tension coil spring 24, which will be described later, but is restrained by coming into contact with a pin 5. 6
is a locking lever, which has a hook 6a and an arm 6b, is supported by a shaft 7, and is given a dextrorotatory behavior by a spring 8, but is restrained by coming into contact with a pin 9. . Reference numeral 10 denotes a setting operation lever, which forms a gear 10a that meshes with the gear 3b of the setting board, and is supported by a shaft 11. Reference numeral 13 denotes a hold lever, which has a pin 13a planted thereon, is supported by a shaft 14, and is given a dextrorotatory habit by a spring 15.
The iron piece 16a of the iron piece lever 16, which will be described later, is an electromagnet Mg.
It is restrained by coming into contact with the Reference numeral 16 denotes an iron piece lever having an iron piece 16a, which forms an arm portion 16b and is pivotally supported by the shaft 14. A hold spring 17 is stretched between the iron piece lever 16 and the hold lever 13. 18 is a swing lever,
A pin 18b forms a hook 18a and serves as an operating part.
is mounted on the set operating lever 10 by a shaft 19, and is given a levorotatory behavior by a spring 20, but is restrained by abutting against a stopper 21. Note that the pin 18b is coaxially located above the shaft 11. Reference numeral 23 denotes an opening/closing lever, which forms a bifurcated arm portion 23a, a semicircular pin 23b,
A pin 23c is installed and pivotally supported by the shaft 11, and a dextrorotatory behavior is given by a tension coil spring 24, which will be described later. It is closely suppressed. Reference numeral 24 denotes a tension coil spring, which is stretched between the pin 3c of the setting board 3 and the pin 23c of the opening/closing lever 23. 25 is sector ring, pin 25
a and 25b, the pin 25a engages with the forked arm portion 23a of the opening/closing lever 23, and the pin 25
b fits into the cam slot 26a of the shutter blade 26. Mg is an electromagnet and So is a power switch.

Next, the operation of the above configuration will be explained.

First, to set the shutter, use the set operation lever 10.
The setting board 3 is rotated to the left by this clockwise rotation, the tension coil spring 24 is charged, and the hook 3a engages with the hook 6a of the locking lever 6 to be restrained. On the other hand, the swing lever 18 rotates slightly to the right as the set operation lever 10 rotates to the right, and eventually the hook 18a engages with the semicircular pin 23b of the opening/closing lever 23. Even in the engaged state, the pin 18b is coaxial with the shaft 11. The status of this shutter set completion is
As shown in the figure.

Subsequently, the shutter release is performed by pressing down the release plate 2, and first the protrusion 2a closes the power switch So. This closure causes the electromagnet to
Mg is energized and attracts the iron piece 16a. When the release plate 2 is further pushed down, the protrusion 2c pushes the arm 6b of the locking lever 6 to rotate it to the left, and before that, the protrusion 2b causes the hold lever 13 to rotate to the left.
By turning the locking lever 6 to the left, the setting board 3 is released from its restraint, and is turned to the right by the restoring force of the tension coil spring 24, causing the setting operation lever 10 to turn to the left.
This left rotation causes the swing lever 18 to lock onto the hook 18a.
The opening/closing lever 23 is opened by the engagement of the semicircular pin 23b.
is rotated to the left, and the sector ring 25 is rotated to the right to open the shutter blade 26. On the other hand, before that, the hold spring 17 is charged by left rotation of the hold lever 13, and the iron piece lever 16 is biased with a left rotation driving force. This state is shown in FIG.

Then, by the action of an exposure control circuit (not shown), when the appropriate exposure time has elapsed, the electromagnet Mg is de-energized. Then, the iron piece lever 16 is rotated to the left by the restoring force of the hold spring 17, and the arm portion 16b
pushes the pin 18b to rotate the swinging lever 18 to the right and disengage the hook 18a from the half-moon pin 23b. Therefore, the opening/closing lever 23 is connected to the tension coil spring 2.
The sector ring 25 is rotated to the right by the restoring force of 4, and, contrary to the above, the sector ring 25 is rotated to the left and the shutter blade 26 is closed. This state is shown in FIG.

After that, by releasing the release plate 2, the hold lever 13 and the iron lever 1
6. The lock lever 6 rotates to the right and returns to the original state as shown in FIG. 1, completing one photographing operation.

In addition, although the case where the aperture 1a closes after being fully opened has been described above, the case will be explained because the aperture 1a may be closed in the middle of opening.

In this case, the electromagnet should be
When the Mg current is cut off, the engagement between the hook 18a and the half-moon pin 23b is similarly released, and the opening/closing lever 23 rotates to the right to close the shutter blade 26. Meanwhile, the set board 3 continues to turn to the right.

Here, the action of the tension coil spring 24 will be explained.

First, the operating principle of a single tension coil spring is to provide a difference in the amount of restoring displacement at both ends of the tension coil spring. For this purpose, the distance from the shaft 4 of the setting board 3 to the pin 3c is L ₁ , the distance from the shaft 11 of the opening/closing lever 23 to the pin 23c is L ₂ , the radius of the gear 3b of the setting board 3 is R ₁ , and the setting operating lever 10 If the radius of the gear 10a is R ₂ , then L ₁ 〓L ₂
If R ₂ > R ₁ , then L ₁ > L ₂ , or R ₂ > _{R 1 and L 1} > L ₂ .

Therefore, when the hook 18a and the semicircular pin 23b are in an engaged state, the restoring force of the tension coil spring 24 acts as a source of force for turning the set operating lever 10 to the left, and in turn acts as a source of force for turning the opening/closing lever 23 to the left.

Next, the position of the pin 18b (action portion) of the swing lever 18, which is a feature of the present invention, will be explained.

First, set operation lever 10 and opening/closing lever 23
is pivotally supported on the same shaft 11, and the swinging lever 18 is supported by the pin 1.
8b is pivotally supported on the set operating lever 10 so as to be directly above the shaft 11. Therefore, when the shutter release lever 10 rotates to the left from the shutter set state shown in FIG. 2, the swing lever 18 rotates as if the pin 18b were an axis. This means that the contact position between the arm 16b of the iron piece lever 16 and the pin 18b does not change regardless of the turning state of the set operating lever 10.
Furthermore, this means that the depth of engagement between the hook 18a and the semicircular pin 23b is also constant.

In other words, since the position of the action point and the amount of work of the iron piece lever 16 do not change, the iron piece lever 16
The amount of force required to disengage the half-moon pin 23b from the half-moon pin 23b is always constant.

The above is a description of the embodiments of the present invention, but it goes without saying that the present invention is not limited thereto.

For example, the driving force source spring may be a single torsion coil spring 24' as shown in FIG. 5, or separate force source springs may act on the setting member and the opening/closing lever. .
Incidentally, since the other configurations in FIG. 5 are the same as those in FIG. 2, they are given the same numbers and will not be described again.

As for the swing lever, it may be on the set-related member or on the opening/closing lever.
A delay device may be attached to a set-related member or the like.

Further, the iron piece lever may be a sliding type instead of a rotating type, or a mechanically controlled type. Note that the embodiments in these cases are omitted because they can be easily modified from the above-mentioned embodiments.

As described above, the present invention has a structure in which the set-related member and the opening/closing-related member are coaxially supported, and the swinging member is pivoted so that the pressing portion is located on this axis. Even when the member pivots, the pressing portion of the swinging member does not displace, nor does the state of engagement between the swinging member and the opening/closing related member change.

Therefore, there is no variation in mechanical delay, and accurate shutter opening/closing seconds can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment according to the present invention, FIGS. 2 to 4 are explanatory views of the operation of FIG. 1, and FIG. 5 is a plan view of another embodiment according to the present invention. 3...Set panel, 10...Set operation lever,
11... Shaft, 16... Iron piece lever, 16b... Arm, 18... Rocking lever, 18a... Hook, 1
8b...Pin, 23...Opening/closing lever, 23b...
Half-moon pin.

Claims (1)

[Claims for Utility Model Registration] A set-related member that can pivot between a set position and a non-set position, an opening-and-closing member that pivots back and forth to open and close the shutter blade, and the set-related member and the opening-and-closing member. It consists of a swinging member that can be connected, and a release member that pushes an action part formed on the swinging member to release the connection and enable the opening/closing related member to rotate in reverse, the opening/closing related member and the opening/closing related member. A blade opening/closing device for a program shutter, characterized in that set-related members are arranged coaxially, and the operating portion of the swinging member is located on the axis at least in the connected state.