JPH048410Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a focal plane shutter for a camera, and particularly to a focal plane shutter in which a shutter curtain is constructed of a plurality of blades.

(Background of the invention) In a focal plane shutter, which has a driving member connected to a plurality of divided blades, for example, a drive arm, and a biasing member that applies a biasing force to the drive arm to drive the divided blades, The shutter opening is covered by opening the divided blades against the biasing force of the biasing member.
The shutter opening is opened by closing the divided blades by the biasing force. In such a focal plane shutter, a stopper is used as a stop position regulating member to regulate the travel end position when the shutter opening opens, that is, when the divided blades close.

FIG. 3 shows a conventional example of the leading blade group of this type of focal plane shutter, and particularly shows the state at the end of shutter travel. In FIG. 3, pins 3a and 3b are erected on the shutter board 1, and arms 5a and 5b as driving members are rotatably attached to the pins 3a and 3b, respectively. A blade 9a is rotatably attached to the tip of each arm by a pin 7a, and a blade 9b is rotatably attached to the center of each arm by a pin 7b. These four elements constitute a four-bar linkage mechanism. This four-bar linkage mechanism is biased by a clockwise force from a spring 11 via an arm 5b. At the end of the shutter run, the arm 5b is attached to the elastic stopper 13a, which serves as a drive member stop position regulating member, to the blades 9a, 9b.
The positions of the respective stoppers are determined so that they simultaneously collide with the elastic stopper 13b serving as a blade group stop position regulating member.

However, when the blades 9a and 9b that close the shutter opening 1a rotate to the right due to spring force to open the shutter, and then the arm and the blade group collide with the stoppers 13a and 13b, the kinetic energy of the four-bar linkage mechanism is lost. Stopper 1
3a and 13b may be deformed, causing the four-bar linkage mechanism to overshoot and stop as shown in FIG. In this case, an undesired force is applied to the attachment portion between the blade and the arm. This attachment part is the weakest part of the focal plane shutter mechanism, and if excessive force is frequently applied to it, its durability will be impaired. Furthermore, the mounting positions of the stoppers 13a and 13b regulate the shutter travel end position, and are determined so that the arm 5b and the blades 9a, 9b collide with the corresponding stoppers 13a, 13b at the same time. Due to manufacturing tolerances, they may not necessarily collide at the same time.
In particular, when the blades 9a, 9b collide with the stopper 13b first, most of the kinetic energy of the four-bar link mechanism is transferred to the blades 9a, 9b.
3b, but the reaction force generated between the blades 9a, 9b and the stopper 13b at that time is transmitted to the attachment part of the arm and the blade, and therefore,
Undesired force is applied to the attachment part of the arm and the blade. Furthermore, if the blades 9a, 9b collide with the stopper 13b first, after the travel ends, the four-bar linkage mechanism is deformed by the spring force of the spring 11 as shown in FIG. 4, and the arms 5a, 5b and the blade are 9a,
If the spring force is large, it is not preferable in terms of strength because the spring remains stationary with force applied to each connection portion with 9b.

(Purpose of the invention) The purpose of the invention is to reduce the impact force applied to the connection between the drive member and the blade when the shutter ends running, and to The object of the present invention is to provide a focal plane shutter that does not apply force.

(Summary of the invention) In the present invention, when the split blade ends traveling, the drive member first collides with the first stop position regulating member, and the kinetic energy of the four-bar link mechanism of the focal plane shutter is absorbed, and then The mounting positions of the first and second stop position regulating members are determined so that the split wing collides with the second stop position regulating member and the split wing is prevented from overtravelling.

(Example) Figure 1 shows an example of the present invention.
Only the leading blades are shown. The same parts as in FIG. 3 will be described with the same reference numerals.

The shutter board 1 has a shutter opening 1a,
Pins 3a and 3b and a spring locking pin 15 are provided upright. Further, a stopper 13a, which is a stop position regulating member for the blade driving member, and a stopper 13b, which is a stop position regulating member for preventing the two blades from overtravelling, are attached at positions as will be described later. These stoppers 13a and 13b are made of an elastic material such as rubber. Arm 5a is attached to pin 3a.
However, an arm 5b is rotatably attached to the pin 3b. A pin 7 is attached to the tip of the arms 5a and 5b.
A leading blade 9a is rotatably attached by a pin 7b, and a leading blade 9b is rotatably attached to the center of each arm by a pin 7b. As mentioned above,
These four elements constitute a four-bar linkage mechanism. One end of the torsion spring 11 is hooked to the arm 5b, and the other end of the torsion spring 11 is hooked to the spring locking pin 15, and the spring force of the spring 11 as a biasing member biases the four-bar link mechanism clockwise. There is.

FIG. 1 shows a state where the leading blades 9a and 9b have finished running and are stationary.
The mounting position of the stopper 13b is determined so that a gap δ is created between the lower end surfaces of the stoppers 13a and 9b and the upper surface of the stopper 13b. Therefore, in the stationary state after the four-bar linkage mechanism has finished traveling, the rotation of the arms 5a and 5b due to the biasing force of the spring 11 is prevented by the stopper 13a.
It will be stopped only by In addition, although the gap δ was set to about 0.5 mm in the embodiment, it may be 0.1 mm or more.

The operation will be explained with reference to FIGS. 1 and 2.

Against the spring force of the spring 11, the leading blades 9a, 9b
When the release button is pressed from a state in which the shutter opening 1a is covered by a mechanism (not shown),
The leading blades 9a and 9b rotate clockwise by the spring force of the spring 11, in other words, begin to run, and exposure is started. When the leading blades 9a, 9b reach the travel end position, the arm 5b first collides with the stopper 13a, and most of the kinetic energy of the four-bar linkage mechanism is absorbed by the collision. At this time, the stopper 13a is elastically deformed, and the arms 5a, 5b and blades 9a, 9b are further displaced clockwise by the amount of the deformation, and the leading blades 9a, 9b attempt to travel further clockwise due to their inertia. . This kind of overtravel of the four-bar linkage mechanism causes the leading blade 9
The process ends when a and 9b come into contact with the stopper 13b, and at that time the state as shown by the solid line in FIG. 2 is reached. Thereafter, the deformation of the leading blades 9a and 9b is restored, resulting in the stationary state at the end of the travel shown in FIG.

At the end of running as shown in Figure 2,
When the leading blades 9a, 9b collide with the stopper 13b, force is applied to the connecting portions between the blades 9a, 9b and the arms 5a, 5b, that is, the pin attachment portions of the blades 9a, 9b, but the kinetic energy of the four-bar link mechanism is Most of the force is absorbed during the collision with the stopper 13a (see FIG. 1), and the force applied to the pins 7a and 7b mounting portions when colliding with the stopper 13a is smaller than in the conventional example. In addition, in the stationary state shown in FIG. 1, all the static biasing force by the drive spring 11 acts on the stopper 13a via the arm 5b, so no force is applied to the mounting portions of the vanes 9a and 9b.

In the above embodiment, only two leading blades are shown for convenience of explanation, but it goes without saying that the same configuration can be applied to the trailing blade as well as in the case where there are three or more leading blades. In addition, although the drive spring 11 is directly hooked to the arm 5b to exert a biasing force, a drive lever that rotates coaxially with the arm 5a or 5b is provided, and the drive spring is hooked to the drive lever to apply the biasing force. It may also be applied to an arm, which is a driving member, via a driving lever.

Further, in the embodiment described above, the leading blades 9a, 9b
The above description has been made of the case where the cover travels from a state covering the opening 1a and is overlapped below the opening 1a. However, a configuration similar to that of the above-described embodiment can be adopted even when a plurality of rear blades overlapped above the opening 1a travel to cover the opening 1a. In other words, the arm for the rear blade (5
By driving the rear blades (corresponding to a and 5b), a plurality of rear blades (corresponding to 9a and 9b) pivotally supported by this arm travel, and these blades open to open the opening 1a.
At the same time, a stopper (corresponding to 13a) comes into contact with the traveling arm, and then another stopper (corresponding to 13b) comes into contact with the lowermost rear blade among the plurality of rear blades. You can.

(Effects of the invention) In the present invention, there is provided a first stop position regulating member that regulates the stop position of the drive member connected to a plurality of blades constituting the shutter curtain; A second stop position regulating member positioned so as to collide with a plurality of blades after a collision and restrict excessive travel of the blades is provided.
Most of the kinetic energy of the drive member and the plurality of blades during travel is absorbed by the collision with the first stop position regulating member, and the force applied to the blade attachment portion when the blade collides with the second stop position regulating member. becomes very small. Further, in a stationary state after the blade group has finished traveling, the biasing force acting on the drive member acts only on the first stop position regulating member, and no force is applied to the attachment portion of the blade. As described above, according to the present invention, the durability of the blade attachment portion can be improved.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, in which FIG. 1 shows a stationary state after running, FIG. 2 shows an overrunning state at the end of running, and FIGS. FIG. 4 shows a conventional example, FIG. 3 shows a stationary state after running, and FIG. 4 shows a deformed state at the end of running. 5a, 5b...Arm (driving member), 7a, 7
b...pin, 9a, 9b...blade (split blade),
11... Spring (biasing member), 13a, 13b...
Stoppers (first and second stop position regulating members),
δ...Gap.

Claims (1)

[Claims for Utility Model Registration] A plurality of divided blades that are movable between an initial position in which the shutter opening is opened and a travel completion position in which the shutter opening is closed; A focal plane shutter equipped with a plurality of divided blades that can be displaced to different positions, comprising: a drive member connected to at least one of the divided blades; and a drive member that moves the divided blades to the initial position via the drive member. urging means for urging in a first direction from the initial position to the travel completion position; and when the divided blade travels from the initial position to the travel completion position and reaches the travel completion position, a first stop position regulating member that comes into contact with the member; and a second stop position regulating member that comes into contact with the split wing when the split wing reaches the travel completion position, and the split wing includes: As a result of the traveling, the driving member contacts the first stop position regulating member and then contacts the second stopping position regulating member to complete the traveling, and after completing the traveling, the first direction is A focal plane characterized in that a positional relationship between the first and second stop position regulating members is defined so that the first and second stop position regulating members come to rest at a position slightly separated from the second stop position regulating member in the opposite direction. Shyatsuta.