JPS5937776Y2 - focal plane ivy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a focal plane shutter, and more specifically to a focal plane shutter equipped with a device for preventing bounce of the focal plane shutter curtain that occurs at the end of its travel.

It is extremely difficult to quickly stop a curtain running at high speed at the end of its run, and if you try to stop it, the curtain will bounce.

Therefore, it is necessary to effectively absorb the energy of traveling, and focal plane shutters equipped with various types of bounce prevention devices have been proposed and put into practice.

FIG. 11 and FIG. 12 are diagrams showing an example of a conventional bounce prevention device.

In the figure, 130. and 140 are a front curtain winding upper shaft and a trailing curtain winding upper shaft, respectively.

Each axis has a leading curtain piece 134 and a trailing curtain piece 144.
is fixed.

The leading curtain piece 134 is provided with a spiral groove 134a that guides the leading curtain regulating lever 135 and has an end portion that abuts the tip 135a of the lever 135 when the leading curtain ends traveling.

Similarly, the trailing curtain piece 144 is provided with a spiral groove 144a that guides the trailing curtain regulating lever 145 and has an end portion that abuts the tip 145a of the lever 145 when the trailing curtain ends traveling.

Each regulating lever 135, 144 is received by a common shaft 136, and the tip of each lever moves up and down in accordance with the rotation of each hoisting shaft.

One end of the shaft 136 is received at a fixed position 136a within the camera body, and the other end is received at one end of a lever 166 rotatably provided around the shaft 183.

The other end of the lever 166 is brought into contact with a piston 168b of an air cylinder 168 having a spring 168a inside.

Immediately before the end of each curtain run, the groove end of the piece is
45, push the shaft 136, and release the lever 16.
6 slightly counterclockwise and rotate the piston cylinder 16.
Bounce is prevented by allowing the piston cylinder 168 to absorb the kinetic energy while pushing the piston 8b.

With such a tank bottom, bouncing of each curtain can be effectively prevented.

However, there remained a problem that the entire device was somewhat complicated.

An object of the present invention is to further improve the curtain bounce prevention device as described above, and to provide a focal plane shutter having a curtain bounce prevention device that can prevent the curtain from bouncing with a simple device.

In order to achieve the above object, the focal plane shutter according to the present invention is a focal plane shutter having a device that applies a brake to the movement of the upper curtain winding shaft near the end of the curtain movement to prevent the curtain from bouncing. Either the upper curtain winding shaft or the trailing curtain winding shaft has a coil spring that is provided integrally with the axis aligned with one or both, and the tip of the coil spring is inserted between the windings of the coil spring, and the winding shaft is connected to the winding shaft. and a regulating lever that is pivoted so that its tip moves up and down as the coil spring rotates, and the tip of the regulating lever is sandwiched between the coil springs when one end side of the coil spring is tightly wound and the curtain ends traveling. The bottom of the tank is equipped with a curtain bounce prevention device that applies a brake to the rotation of the hoisting shaft.

According to the above structure, bouncing of the curtain can be prevented with a very simple tank bottom, and the purpose of the present invention can be completely achieved.

Hereinafter, the focal plane shutter according to the present invention will be described in more detail with reference to the drawings.

1 and 2 are perspective views showing an embodiment of the focal plane shutter according to the present invention, in which FIG. 1 shows the winding end state, and FIG. 2 shows the shutter end state.

When the hoisting lever 1 is rotated counterclockwise in FIG. 1, the rotational force applied to the hoisting lever 1 is transmitted to the final gear 5 via the transmission gear 2.degree. 3.4.

A stop plate 6 is provided on the upper side of the final gear 5, which serves to stop the winding at the end position.

The gear 1 is connected to the lower side via a pin 14 provided on the gear 13.
3 is further provided on the gear 13 with a pin 15, and the gear 16 is connected to the gear 16.
A hoisting plate 7 is provided with a clutch plate 9 that rotates the gears 16 in the directions of the arrows by means of pins 17 provided therein.

The clutch plate 9 is rotated clockwise around a shaft 10 by the force of a spring 11.

When the lever 20 is given a rotational force in the counterclockwise direction by the spring 22, the claw 20b at the tip is not restrained by the stop plate 6a, and the other end is not restrained by the pin 19 provided on the gear 16. is adapted to be lightly pressed against the outer periphery of the stop plate.

The front curtain winding shaft 27 is rotatably supported, and a tip winding gear 23 is fixed to the lower end of the shaft.

This gear 23 meshes with the gear 13. Further, a leading curtain tensioning plate 39 is fixed to the upper end, and a regulating spring 38 and an adjusting nut 37 are provided.

A trailing curtain winding gear 24 is fixed to the lower end of the trailing curtain winding shaft 28 and meshes with the gear 16.

A rear curtain tensioning plate 42 is fixed to the upper end, and a regulating spring 41. An adjustment nara) 40 is provided.

There are cam parts 39 on the lower outer periphery of the front curtain and rear curtain tension plates, respectively.
a, 42a are provided.

Further, the lower ends of the regulating springs 38 and 41 are tightly wound.

A leading spring shaft 31 is fixedly provided, and a hollow leading spring drum 33 is rotatably supported on this shaft 31.

The front curtain spring drum 33 is always given a force in the direction of winding the front curtain (clockwise) by a front curtain spring 35 located inside.

Rollers 30a and 30b are provided above and below the drum for guiding the string of the trailing curtain.

A trailing spring shaft 32 is fixedly provided, and a hollow trailing spring drum 34 is rotatably and loosely mounted on this shaft 32.

The trailing curtain spring drum 34 is always given a force in the direction of winding up the trailing curtain (clockwise) by a trailing curtain spring 36 located inside.

One end of the leading curtain 29 is attached to the leading curtain spring drum 33, and the other end is attached to a metal plate 29e.

There are strings 29c above and below this metal plate 29e. 29d is attached.

These strings 29c and 29e are the leading curtain guide roller 29a.

29d, and is attached to the front curtain winding drum 25 so that it can be wound up.

One end of the trailing curtain 30 is attached to the trailing curtain winding drum 26, and the other end of the trailing curtain 30 is attached to a metal plate 30e, and strings 30c, 30d are attached to the upper and lower ends of this metal plate.
is installed.

A current is supplied to the electromagnet 49a from an electric circuit (not shown), and an attractive force is applied for a time corresponding to the shutter speed.

The trailing curtain tensioning lever 46 is provided with a counterclockwise rotational force by a spring 54.

An electromagnetic iron piece 48 that is attracted to an electromagnet 49 is provided at one end of the lever 46 .

A portion 46a of this lever engages with a cam portion 42a to stop the clockwise rotation of the trailing curtain tensioning plate 42 when the trailing curtain is in the rolled-up position.

The front curtain tensioning lever 45 is always given a clockwise rotational force by the force of the spring 52.

The leading end portion 45a engages with the front curtain tensioning plate 39a to stop clockwise rotation.

43 and 44 are regulating levers for regulating the operation end positions of the leading curtain and the trailing curtain, respectively.

47 is the common axis of these levers. Both ends are fixedly attached.

Each regulation lever 43, 44 has a claw portion 43a, 44a provided at the tip end of each regulation lever 43, 44 with a regulation spring 38.
The claw portions 43a and 44a are loosely inserted into the spiral portion of 41 and move up and down along with the rotation of the regulating spring.

The regulating springs 38, 41 rotate in accordance with the travel of their corresponding curtains, and the pawl portion of the regulating lever is gradually lowered, and when the curtain approaches the end of its operation, the pawl portion enters the close contact portion of the regulating spring.

When the operation of the curtain is stopped at this close contact part, the convex parts 39b, 42b of each tension plate 39, 42 and 43 of the regulating lever
a, 44a hits and the operation of the curtain is prevented.

53 is a trailing curtain release lever for pushing the trailing curtain tensioning lever to release the tensioning plate.

A spring 58 provides a force for pushing the trailing shutter release lever 53, but the lever 56a holds the lever 56a before pushing down a shirt button (not shown).

The lever 56 is configured to move in the direction of the arrow in FIG. 1 when the shirt button is pressed down.

The front curtain release lever 50 is a lever for pushing the front curtain tension lever to release the tension plate 39.

A spring 51 applies a force to push the front curtain release lever, but before the lever 56 moves in the direction of the arrow, it engages with the levers 57 and 50a and is held in the position shown in FIG. ing.

When the lever 56 moves, the 56a section pushes down the 57a section and disengages it from the 50a section.

The lever 55 has a spring 58 for moving the lever 53.
It is a lever to give power.

The lever 56 and the lever 53 are provided coaxially and separately rotatably.

The operation of the shutter configured as above will be explained step by step.

Explanation of the operation from the start to the end of shutter operation (see Figure 1).

When the lever 56 moves in the direction of the arrow in connection with pressing down the shirt button (not shown), the rear curtain release lever 5
3 moves in the direction of the arrow by the force of the spring 58.

However, current is supplied to the electromagnet 49 from an electric circuit (not shown), and the iron piece 48 provided on the rear curtain tensioning lever 46 is attracted to the electromagnet 49, so the rear curtain is tensioned by the force of the release lever 53 and the spring 58. Even if you press the lever 46,
The trailing curtain tension lever continues to maintain the position shown in Figure 6.

Therefore, rotation of the trailing curtain tension plate 42 and the regulation spring 41 integrated therewith in the clockwise direction (FIG. 6) is prevented.

On the other hand, due to the movement of the lever 56, the lever 57 is moved at the 56a portion.
57a is pushed and rotated in the direction of the arrow in FIG.

As a result, the engagement between the leading curtain tensioning lever 45 and the cam portion 39a of the leading curtain tensioning plate 39 is released, the leading curtain winding shaft 27 is allowed to rotate clockwise, and the leading curtain 29 is attached to the leading curtain spring drum. 33
It is wound up and moved in the opening direction.

When the leading curtain winding shaft 27 is rotated as the leading curtain travels, and the leading curtain tensioning plate 39 is rotated clockwise, the claw portion 4 of the regulating lever 43, which is loosely in contact with the spiral portion of the regulating spring 38, is rotated.
3a is moved downward, and when the leading curtain approaches a prescribed position, it enters the close contact portion of the regulating spring 38.

Here, the claw portion 43a of the regulation lever 43 is connected to the regulation spring 3.
8 further moves downward while expanding the front curtain tension plate 39. Due to its braking action, the rotation of the leading curtain tensioning plate 39 becomes slow, and the claw portion 43a of the regulating lever 43 slowly moves downward from the front curtain tensioning plate 39.
It corresponds to 9b.

FIGS. 3 and 4 show a state in which the claw portion 43a of the restriction lever, the end portion of the restriction spring, and the tension plate 39b are brought together and the movement of the front curtain is stopped.

When the supply of current from a circuit (not shown) to the electromagnet coil 49a is cut off after or before the end of the leading curtain run, the electromagnet 49 loses its attractive force.

As a result, the trailing curtain tensioning lever 46 is similar to the trailing curtain release lever.
The cam portion 42a of the trailing curtain tension plate 42 is
being pushed out.

In other words, the position shown in FIG. 6 cannot be maintained, and the second curtain 3
0 starts running.

When the rear curtain 30 starts running, the claw part 44a of the regulation lever 44 is moved downward according to the rotation of the rear curtain tensioning plate 42, and just before the end of running, it enters the contact part of the regulation spring 41 and slowly lowers before stopping at 42b. do.

In connection with trailing curtain travel, the gear 16 rotates counterclockwise;
At the travel end position, push the 20a part of the lever 20 with the pin 19 and pull out the 20b part from the 6a part of the stop plate 6 (see Figure 8).
.

At the same time as the 2Ob part comes out of the 6a part of the stop plate 6, the pin 2
The portion 9a of the clutch plate 9 that was pressed by the spring 11 is released, and the portion 9b of the clutch plate 9 is moved to the position shown in FIG. 7 by the spring 11.

Next, the operating state during hoisting will be explained.

As mentioned above, at the end of trailing curtain travel, the engagement between the stop plate 6a and the lever 20b is released, and at the same time, the clutch plate 9b returns to its home position, so the final gear 5 is in a rotatable state. It has become.

When the winding lever 1 is rotated counterclockwise, the force is applied to the gear 2. 3. 4 to the final gear 5.

As the final gear 5 rotates counterclockwise, the portion 9b of the clutch plate 9 first rotates the pin 14 fixed to the gear 13.

At this time, since the gear 13 and the leading curtain winding gear 23 are meshed with each other, the leading curtain winding drum 25 rotates and winds up the leading curtain 29.

At this time, the rear curtain 30 is at the travel end position.

Subsequently, since the gear 16, which rotates the pin 15 fixed to the gear 13 and the pin 17 fixed to the gear 16, and the trailing curtain winding gear 24 are engaged, winding of the trailing curtain is started.

When the gear 16 rotates, the pin 19 that is fixed is connected to the lever 2.
0 is no longer pressed, the lever 20 is allowed to move clockwise, and the claw portion 20b of the lever comes into loose contact with the circumferential portion of the stop plate.

When the final gear 5 reaches the position where it has completed one revolution (see FIG. 9), the leading curtain 29 is wound up further than the position shown in FIG. 1, and the trailing curtain 30 is also slightly wound up.

At this time, the claw portion 20b of the lever 20, which was in contact with the outer circumference of the stop plate 6, enters the stop plate 6a while pushing one end 9a of the clutch plate 9 with the pin 21 by the force of the spring 22, and the final gear 5 prevent rotation.

On the other hand, the clutch plate 9b part whose one end 9a part is pushed is the gear 1
It is released from pin 14 of 3.

As a result, the gear 13 with the pin 14 released and the leading curtain hoisting gear 23 that are meshed with each other are no longer restrained and can move in the winding direction (curtain running direction), but the leading curtain is tightened at the returned position. A portion 39a of the disc 39 and a portion 45a of the leading curtain tensioning lever 45 are engaged, and the state shown in FIG. 1 is prevented.

In addition, the gear 16 fixed with the pin 17 released from the pin 15 of the gear 13, and the meshing rear curtain winding upper gear 24 are no longer restrained and move in the winding direction (curtain running direction), but slightly. At the returned position, a portion 42a of the trailing curtain tensioning plate 42 and a portion 46a of the trailing curtain tensioning lever 46 are engaged, and the state shown in FIG. 1 is prevented.

Claw portions 43a and 44a of regulation levers 43 and 44
gradually rises during the winding process, and rises to the position shown in FIG. 1 at the end of winding.

Since the focal plane shutter according to the present invention is constructed as described above, it is possible to easily and reliably prevent bouncing at the end of curtain travel.

The degree of bounce prevention, that is, the degree of braking, can be adjusted very easily by turning the nut holding the coil spring up and down.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a focal plane shutter according to an embodiment of the present invention when winding is completed, and FIG. 2 is a perspective view showing the state when the operation is completed. Figures 3 and 4 are diagrams for explaining the brake device,
FIG. 3 shows the winding-up state, and FIG. 4 shows the state at the end of the operation. FIG. 5 is a diagram showing the relationship between the leading and trailing curtain regulating springs and the regulating lever at the end of the shutter operation. FIG. 6 is a diagram showing the relationship of the tensioning device at the end of winding. 7, 8, 9, and 10 are diagrams for explaining the hoisting device, and FIGS. 7 and 8 are at the end of shutter operation, and FIGS. 9 and 10 are The state at the end of winding is shown. FIGS. 11 and 12 are diagrams for explaining an example of a conventional bounce prevention mechanism for a focal plane shutter. 1...Volume-L lever 2. 3. 4...
...Transmission gear, 5...Final gear, 6...
・Stop plate, 7...Hoisting plate, 9...Clutch plate, 10...Shaft, 11...Spring,
13...Gear, 14...Pin, 15.
...Pin, 6...Gear, 17...
・Pin, 20...Lever, 22...Right, 23...Front curtain winding upper gear, 24...
Trailing curtain winding gear 26... Trailing curtain winding drum, 27
...First curtain, 2nd axis, 29...First curtain, 3
0... Rear curtain, 31... Front curtain spring shaft, 32... Rear curtain spring shaft, 33...
... Leading curtain spring drum, 34... Trailing curtain spring drum, 35... Leading curtain spring (spring), 36...... Trailing curtain spring (spring), 37.
...Adjustment nut, 38...Regulation spring (spring), 39...Front curtain tension plate, 40...
...Adjustment nut, 41...Regulation spring (
spring), 42... Rear curtain tension plate, 43...
・Front curtain regulation lever, 44... Rear curtain regulation lever,
45... Leading curtain tensioning lever, 46... Trailing curtain tensioning lever, 47... Regulation lever shaft, 48...
...Electromagnetic iron piece, 49...Electromagnet, 50.
...Front curtain tension lever, 51 ...Spring, 5
3... Rear curtain release lever - 154...
Spring, 55...Luv, 56...Luv,
57...Lever, 58...Spring.

Claims (1)

[Scope of utility model registration request] In a focal plane shutter that has a device that prevents the curtain from bouncing by applying a brake to the movement of the upper curtain winding shaft near the end of the curtain travel, the shaft is set on either or both of the leading winding upper shaft or the trailing curtain winding upper shaft. The control lever includes a coil spring that is aligned and provided integrally with the coil spring, and a regulating lever whose tip is inserted between the windings of the coil spring and whose tip is pivoted so as to move up and down in accordance with rotation of the hoisting shaft. , a focal having a curtain bounce prevention device in which one end side of the coil spring is tightly wound and the tip of the regulating lever is sandwiched between the coil springs when the curtain finishes traveling, thereby applying a brake to the rotation of the two winding axes. Plain shutter.