JPS6039855Y2 - Squeezing mechanism of bellows device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a constriction mechanism of a bellows device for arbitrarily confining a lens with an open aperture.

Normally, when a photographic lens is attached to a lens mount, the aperture of the lens is opened.

When it is desired to narrow down the lens for exposure measurement, the aperture knob is operated from the outside, and the amount of movement of the aperture knob caused by the operation is transmitted to the lens aperture lever provided on the lens to perform narrowing down.

In addition, in a bellows device of the type that connects a cable release to the lens mount to narrow down the aperture of the photographic lens from wide open to a predetermined value in conjunction with the camera's shirt release, it is possible to The aperture knob and cable release connection were provided separately.

In the bellows device, there are cases where the lens mount is not provided with any accessories, and cases where a tilt mechanism such as a swing and shift mechanism is provided.

In the former case, this is not a problem as there is plenty of space, but in the latter case, by installing a tilt mechanism, it can be used as an interlocking member from the aperture knob and cable release connection to the lens aperture lever. Space becomes very limited.

Therefore, a drawback has arisen in that it is difficult to separately provide the aperture knob and the cable release connection section.

The purpose of this invention is to reduce the space required to install the aperture knob and the cable release connection, and to provide a simple structure by arranging the interlocking mechanism from both of them to the lens aperture lever in a small space. To provide a throttle mechanism for a bellows device that can be operated reliably and easily by either a knob or a cable release.

Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a front view of an embodiment of the present invention, with the lens in an open state.

Figure 2 is a front view when the lens is stopped down by operating the aperture lever, Figure 3 is a front view when the cable release is connected and the lens is closed down, and Figure 4 is a side view when the lens is opened. .

In FIG. 1, reference numeral 1 denotes a lens mount to which a lens (not shown) is attached and slides back and forth on a rail (not shown).

An interlocking ring 3 is rotatably provided on the lens mount 1, and the interlocking ring 3 has a first aperture lever 2 that engages with the aperture lever 2 of the lens, which is always biased in the aperture direction (clockwise).
It has a retaining part 3a.

Also, the interlocking ring 3 has a second retaining portion 3b that engages with the spring 4.
, and is always biased counterclockwise (lens opening direction) by the spring 4.

Note that the biasing force of the spring 4 is greater than the biasing force of the aperture lever 2 of the lens.

Furthermore, the interlocking ring 3 is provided with a pin 3C.
c is engaged with an interlocking lever 6 that is rotatable about the rotation shaft 5.

The interlocking lever 6 is provided with a pinion 6a fixed thereto.

In this embodiment, the swinging members are the interlocking lever 6 and the pinion 6.
It is composed of a.

There is a first sliding lever 8 that is guided by a sliding lever shaft 7 and can slide left and right, and this first sliding lever 8 is provided with a rack 8a, and this rack 8a and a pinion 6a are engaged. The interlocking lever 6 and the first sliding lever 8 are thus interlocked.

Further, the first sliding lever 8 is provided so as to overlap with the first sliding lever 8.
There is a second sliding lever 9 which is slidable like the sliding lever 8, and its protrusion 9a contacts the interlocking lever 6, so that the interlocking lever 6 and the second sliding lever 9 interlock with each other.

There is a cable release connection part 1a on the side of the lens mount 1.
is provided, and a narrowing knob 1 is provided on the outer periphery.
0 is rotatably provided around a second interlocking pin 12, which will be described later.

The narrowing knob 10 is provided with a cam 10a, which interlocks with the sliding lever 8 via a first interlocking pin 11.

The above-mentioned second interlocking pin 12 is linearly provided in the cable release connecting portion 1a, and transmits the movement of the plunger 14 of the cable release 13 to the second sliding lever 9.

In this embodiment, the first member is the second sliding lever 9 and the second sliding lever 9.
The second member is composed of a first sliding lever 8 and a first interlocking pin 11.

Next, we will discuss the operation.

When the narrowing knob 10 is moved from the position shown by the solid line to the position shown by the two-dot chain line in FIG. direction, and slide the sliding lever 8 to the left.

As a result of this sliding, the pinion 6a is rotated counterclockwise by the rack 8a.

Therefore, the interlocking lever 6 is rotated counterclockwise, and the interlocking ring 3 is rotated clockwise via the pin 3c.
As a result, the lens is narrowed down.

This state is shown in Figure 2. When you release your hand from the aperture knob 10, the interlocking ring 3 is biased by the spring 4, so
The state shown in FIG. 1 is returned.

Next, when the button (not shown) of the cable release 13 is pressed, the plunger 14 protrudes in the axial direction and the second interlocking pin 1
2 in its axial direction and slide the second sliding lever 9 to the left.

The protrusion 9a pushes the interlocking lever 6 to rotate it counterclockwise, and as in the case described above, the interlocking ring 3 is rotated clockwise, so that the lens is narrowed down.

The state is shown in FIG.

When the button of the cable release 13 is released, the lens is similarly opened and returns to the state shown in FIG. 1.

If the linear movement of the first interlocking pin 11 obtained by rotating the narrowing knob 10 is different from the linear movement of the second interlocking pin 12 obtained by operating the cable release 13, the sliding lever 8 is attached to the interlocking lever 6. The ratio of the distance from the rotary shaft 5 to the position where the and Shaft 5 or pinion 6a and rack 8a
By appropriately setting the ratio (lever ratio) between the first distance and the second distance to the engaging portion, the above-mentioned difference in momentum can be canceled out and the amount of rotation of the interlocking ring 3 can always be made the same.

In the case of this embodiment, the first interlocking pin 11 and the first sliding lever 8, and the second interlocking pin 12 and the second sliding lever 9 are each separate bodies, but this is mainly because For manufacturing reasons and from the viewpoint of operation, they may each be integral.

As described above, according to the present invention, since the aperture knob and the connecting portion of the cable release are arranged coaxially, they can be provided without taking up much space.

Further, since the first member, second member, and swinging member are arranged close to each other between the connecting portion of the aperture knob and cable release and the aperture lever of the lens, the space required for arranging them is also reduced.

Furthermore, since this principle is used in the swinging member and the swinging member is caused to swing by the first member or the second member,
The swinging member can be easily and reliably swung, and if the first member or the second member requires a larger force to operate, the rack and pinion are used to reduce the operating force. It is also easy to operate.

Even if there is a difference between the linear momentum of the first member and the side of the second member, the ratio of the lengths from the swing center of the swing member to the contact points of the first and second members is appropriately selected. , it becomes possible to move the aperture lever of the lens by the same amount.

[Brief explanation of drawings]

Fig. 1 is a front view of the embodiment of the present invention, Fig. 2 is a front view of the main parts of the embodiment of Fig. 1 with the lens narrowed down by operating the aperture knob, and Fig. 3 is a front view of the cable release. The first lens with the lens closed down by pressing the button.
FIG. 4 is a front view of the main parts of the embodiment shown in the figure, and FIG. 4 is a side view of the lower part of the embodiment shown in FIG. 1 for explaining the operation of the aperture knob. Explanation of the symbols of the main parts, aperture lever...2, aperture movement member...3, plunger...00.・1
4. Cable release...13. Cable release connection section...la. Aperture knob...
・10. Interlocking lever...6. Axis of interlocking lever・
...5, Second member...8,11, First member...9,12°

Claims (1)

[Scope of Claim for Utility Model Registration] In the aperture mechanism of a bellows device that narrows down the aperture of a photographic lens from wide open to a predetermined value, the aperture lever engages with the aperture lever of the photographic lens and moves to allow the aperture lever to operate. a diaphragm interlocking member that operates the diaphragm linking member; a cable release connecting portion to which the cable release is connected and having a linear hole such that the plunger of the cable release can move linearly in conjunction with the shirt release; and a cable release connecting portion surrounding the cable release connecting portion; and an aperture knob rotatable around the cable release connection part; an interlocking lever whose one end is coupled to the aperture interlocking member and whose other end is swingably supported around a predetermined shaft; a swinging member that is rotatable from a pinion that rotates integrally with the interlocking lever and that moves the aperture interlocking member by swinging; and a swinging member that moves the aperture interlocking member by swinging; a first member that engages with the member and transmits the linear motion of the plunger to the swinging member to swing the swinging member; and a second member that is separated from the predetermined axis by a second distance different from the first distance. a second member that engages with the swinging member and transmits the rotational motion of the narrowing knob as a linear motion to the swinging member to swing the swinging member; the first member and the second member; Among the members, a member close to the predetermined axis is provided with a rack that engages with the pinion, and the engagement between the rack and the pinion causes the linear movement of the first or second member to cause the swinging of the swinging member. Even if the linear momentum of the first member and the second member is different, the swinging member swings by the same amount.
and the second distance.