JPH0210519Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a safety device for preventing erroneous operation in the connection between the film winding and shutter release of a single-lens reflex camera. Although such security devices have already been repeatedly implemented and improved, in recent years it has become necessary to unfasten the film, which is a requirement of the security device, only after one cycle of shutter operation necessary for shooting has been completed. Some methods have been devised, but they are:
It had a complicated structure, including the provision of a new unwinding member that interlocked with the mirror. The present invention provides a safety device that performs simple and reliable unfastening and is configured to satisfy the following requirements.

a The shutter button is prevented from being pressed before and during film winding.

b. After the film winding is completed, the shutter button can be pressed and double winding is prevented.

c. Film winding is prevented while the shutter is operating, when the mirror is not in the return position, and even if the mirror returns, while the shutter button is pressed down.

d When the mirror return is completed and the shutter button is activated, the film winding is released and winding becomes possible.

In order to meet the above requirements, the present invention uses a mirror charge member and a spring provided on the member to
It is characterized by directly or indirectly controlling blocking or cancellation.

Embodiments of the present invention will be described in detail below with reference to the drawings. Reference numeral 1 denotes a winding shaft connected to a winding lever (not shown), on which a charge cam 2 is fixedly installed. The charge cam 2 is made up of a bulging peripheral part 2a, a ratchet part 2b, and a locking part 2c, and has a boss 2d on the upper surface and a spring (not shown) on the lower surface that gives left rotation about the shaft 3 implanted therein. A feeding claw 4 is provided. Also, under the charge cam 2,
A feed regulating cam 5 having the same center as the shaft 1 is fitted into a gear (not shown), so that the feed pawl 4 transmits only the leftward turning movement of the charge cam 2 to the feed regulating cam 5. A ratchet pawl 7 biased by a spring 8 about a shaft 6 comes into contact with the ratchet portion 2b of the charge cam. The feed regulating lever 10, which enters the rotation range of the feed regulating cam 5 and regulates the amount of film feed, has a vertically bent portion 10a and a claw portion 10b.
It is given levorotation about the axis 9 by a spring (not shown). Reference numeral 12 denotes a locking lever that is pivotally connected to the shaft 11 and has levorotatory properties using a spring (not shown);
A protrusion 12 that comes into contact with the locking portion 2c of the charge cam
b, and an arm 12a that is regulated by a spring 16, which will be described later.
and has. 13 is a release plate having a release button on its upper part. Reference numeral 15 designates a mirror charge lever rotatably mounted around a shaft 14, which includes an arm 15a that comes into contact with a boss 2d planted on the charge cam, and a protrusion that comes into contact with the vertically bent portion 10a of the feed regulation lever. 15b, and further includes an arm 15e that comes into contact with the mirror operating lever 17. Further, a spring 16 is held on the mirror charge lever 15 with biasing force stored at two locations, ie, the vertically bent portions 15c and 15d.

Next, the operation will be explained. FIG. 1 is a diagram showing the state before winding up. Since the mirror operating lever 17 is in the return position before winding,
The protruding portion 15b of the mirror charge lever 15 engages with the vertical bent portion 10a of the feed regulating lever, and the spring 16 on the lever engages with the arm 12a of the locking lever, so that the claw portion 10b of the feed regulating lever is engaged. , the protrusions 12b of the locking levers are removed from their respective locking positions, and are in a state where they can be rolled up.
A part of the arm 12a of the locking lever enters the movement range of the release plate 13 and prevents the release button from being pressed.

FIG. 2 is a diagram showing a state in the middle of winding.
When the winding lever is rotated to the left from the state shown in FIG. 1, the feed pawl 4 transmits rotation to the feed regulation cam 5, and the boss 2d on the charge cam engages with the arm 15a of the mirror charge lever 15. By turning the lever to the right, the arm 15e comes into contact with the mirror operating lever 17, and charging of the mirror is started. Further, by turning the mirror charge lever 15 to the right, the feed regulating lever 10 can be turned to the left, and the claw portion 10b of the lever engages with the convex portion of the feed regulating cam 5, thereby increasing the amount of film winding. is regulated. The post-restriction winding lever is turned clockwise and returned to its original position by the restoring force of a spring (not shown), thereby completing the film winding operation. (Fig. 3) On the other hand, during this winding operation, the locking lever 12 is released from the restriction of the spring 16, but the protrusion 12b abuts against the bulging peripheral part 2a of the charge cam, preventing the left turning movement, and the winding During the process, pressing the release button continues to be blocked.

FIG. 3 is a diagram showing a state in which winding is completed.
When the mirror charge is completed, the mirror operating lever 17 is locked at that position, and the mirror charge lever 15 is in a state where it is not subject to any restrictions and does not give any effect. At this time, the locking lever is allowed to turn to the left for the first time, and its protrusion 12b is placed in a position facing the locking portion 2c of the charge cam, and at the same time, the arm 1
2a exits the movement area of the release plate, and the release button can be pressed. In this state, the feed restriction lever 10 is engaged with the feed restriction cam 5, so double winding is prevented. Next, when the release button is pressed, the mirror goes up, the shutter is released, and the mirror goes down again, ending the shooting. As the mirror descends, it returns to the state shown in FIG. 1 and the winding stop is released.

Figure 4 shows the state in which the release button is still pressed down even after the mirror has returned;
The claw portion 10b of the feed regulation lever is disengaged from the feed regulation cam 5, and the double winding prevention is released, but the locking lever 12 remains closed while the release button is pressed.
is placed in a position where the projection 12b opposes the locking portion 2c of the charge cam against the bias of the spring 16,
Continue to prevent the next winding. Note that when the release button is released, the locking lever 1 is moved by the bias of the spring 16.
2 is turned to the left and returned to the state shown in FIG.

As detailed above, the present invention satisfies the requirements for preventing erroneous operations in the linkage between the film winding and shutter release of a single-lens reflex camera, as mentioned at the beginning, with a simple structure that has not been seen before. Great effects can be expected in terms of reduction in the number of parts, ease of assembly, reliability, etc.

[Brief explanation of the drawing]

Fig. 1 shows the state before winding, Fig. 2 shows the state in the middle of winding, Fig. 3 shows the state when winding is completed, and Fig. 4 shows the state when the release button is pressed. Diagram showing the state. 1... Winding shaft, 2... Charge cam, 2a...
...Bulging peripheral part, 2c...Locking part, 2d...Boss,
4...Feed claw, 5...Feed regulation cam, 10...Feed regulation lever, 12...Latching lever, 13...Release plate, 15...Mirror charge lever, 16
... Spring, 17 ... Mirror operation lever, 3, 6,
9, 11, 14...axis, 10a, 15c, 15d
...Vertical bending section.

Claims (1)

[Scope of utility model registration request] A single-lens reflex camera having a movable mirror includes a charge cam 2 fixed to a winding shaft 1 and provided with a locking portion 2c, and a feed regulating cam 5 fitted to the winding shaft 1 and having the same center as the shaft 1. , a feed regulating lever 10 that engages with the feed regulating cam 5 when the film is fed a predetermined amount, and a release plate 13 that is slidably provided and has a release button on its upper part.
A locking lever 12 is rotatable between a first position where it contacts the release plate 13 and a second position where it does not come into contact with the release plate 13, and a locking lever 12 is provided so as to be able to come into contact with a boss 2d implanted in the charge cam 2. mirror charge lever 15
, a spring 16 that is held with a biasing force stored in the mirror charge lever 15, and a mirror operating lever 17 that is pushed by the rotation of the mirror charge lever 15 to charge the mirror.
When the mirror operation lever 17 returns, the spring 16 held by the mirror charge lever 15 pushes the feed locking lever 12, and the mirror charge lever 15 pushes the regulation lever 10 to prevent film winding. When the locking lever 12 is released, the locking lever 12 enters the movement range of the release plate 13 and prevents the release button from being pressed. During film winding, the locking lever 12 and the feed regulating lever 10 are rotated by the rotation of the mirror charge lever 15. When the mirror is set, the feed regulating lever 10 engages with the feed regulating cam 5 to prevent film winding.
Furthermore, the locking lever 12 engages with the locking portion 2c of the charge cam 2 to prevent double winding, and
When the release plate 13 is out of the movement range, the release button is no longer prevented from being pressed, and while the release button is being pressed, the protrusion 12b of the locking lever faces the locking portion 2c of the charge cam to prevent winding. A security device for linking film winding and shutter release.