JPH0541973B2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a camera shutter.

(Prior Art) FIG. 3 shows a focal plane shutter as a conventional camera shutter.

In the figure, 1 is a shutter base plate, 2 is a blade drive lever shaft, and a main arm rotation shaft 2a is formed at one end. Reference numeral 3 refers to charge lever shafts 3 and 4, which are rotation centers of a charge lever (not shown) for charging the blade drive lever, and reference numerals 5 and 6 refer to auxiliary arm rotation axes;
7 is an aperture formed in the shutter base plate 1; 8 is an aperture for each of the above-mentioned shafts 2, 3, 4,
A hole is formed in the shutter base plate 1 for attaching 5 and 6 by caulking, and 9 is a groove (hole) formed in the shape of the swinging range of a blade drive lever (not shown). 1
0 is a leading blade group, in which a slit forming blade 10c and another divided blade 10d are linked and supported by a caulking portion 10e on the main arm 10a and the auxiliary arm 10b. The main arm 10a is swingably supported by the main arm rotation shaft 2a of the blade drive lever shaft 2, and the auxiliary arm 10b is swingably supported by the auxiliary arm rotation shaft 4. 11 is a rear blade group, which includes a main arm 11a and an auxiliary arm 11;
b, the slit forming blade 11c and the other divided blade 1
1d are linked and supported by the caulking portion 11e. Note that the main arm 11a is connected to the main arm rotation axis 2.
The auxiliary arm 11 is swingably supported by a.
b is swingably supported by the auxiliary arm rotating shaft 4. 12 is a partition plate arranged between the leading blade group 10 and the trailing blade group 11 to prevent interference between the two. Note that an opening 12a corresponding to the aperture 7 is also formed in the partition plate 12. A cover plate 13 is made of a thin metal plate similarly to the shutter base plate 1, and has an opening 13a corresponding to the aperture 7 formed therein. 14 and 15 are spaces, and in order to keep each blade group 10 and 11 running smoothly, each blade group 10c, 10d, 11 is
The tip regions of c and 11d are arranged at sliding positions.

In this conventional shutter structure, the blade drive lever shaft 2, the charge lever shaft 3, the auxiliary arm rotation shaft 4, and the shafts 5 and 6 are attached to the holes 8 of the shutter base plate 1 by caulking. It takes time and costs are also high.

Therefore, in order to reduce costs and simplify the process, the shutter base plate was molded from synthetic resin.
At this time, it is conceivable to integrally mold the various shafts mentioned above at the same time. However, since the shutter base plate is a thin member, when a large force is applied to a synthetic resin molded product from a blade drive lever, charge lever, etc., the force causes deformation, which has a subtle effect on the running of each blade group. It is expected that this will happen. Then, of course, the shutter exposure (seconds)
The accuracy of this cannot be guaranteed, and in the worst case, damage to the shutter base plate due to insufficient strength is expected.

(Object of the Invention) An object of the present invention is to provide a camera shutter having a shutter base plate that does not cause problems in terms of strength even if it is made of synthetic resin by molding, and avoids increasing the size of the shutter.

(Features of the Invention) In a camera shutter having a shutter base plate molded from synthetic resin, the present invention provides a swing area of an arm that runs a blade group that is closer to the shutter base plate in the thickness direction among a plurality of blade groups. The feature is that the thickened part is integrally molded when forming the shutter base plate so that the swinging area of the arm that runs the farthest blade group in the thickness direction is thickened on the running surface side. Strength can be improved without significantly increasing thickness.

(Example) An example of the present invention is shown in FIG. Note that the same configuration as the conventional example is given the same reference numeral, and the explanation will be omitted.

20 is a shutter base plate molded from liquid crystal polymer (LCP) as a synthetic resin material, and includes a blade drive lever shaft 22, a charge lever shaft (hidden and cannot be seen because it is on the back side of the shutter base plate 20),
To attach the main arm rotation shaft 23, the auxiliary arm rotation shaft 24, the partition plate 12 that separates the running space of the leading blade group 10 and the trailing blade group 11, the spacer 14 that keeps the leading blade group 10 running smoothly, and the cover plate 13. The shafts 25 and 26 are integrally molded with the shutter base plate 20. That is, the various shafts 22, 2 mentioned above
3, 24, 25, and 26 are integrally formed at the same time when forming the shutter base plate 20, thereby eliminating the crimping process that was conventionally required.

Reference numeral 27 denotes a rib formed on the edge of the shutter base plate 20 within a range that does not impede the running of both blade groups 10, 11, and can improve strength (prevent warpage, prevent breakage, etc.). 28 is a conventional spacer (third
This is an enlarged part corresponding to the space formed in the space arrangement area of the shutter base plate 20 in order to eliminate the spacer (corresponding to the spacer 15 in the figure). It is possible to improve the strength by removing the Reference numerals 29, 30, and 31 are thickened portions in which the running area 32 of both arms 11a and 11b of the rear blade group 11 is used as a plate thickness reference plane, and the areas other than the area 32 are increased in thickness. can be fulfilled. Note that the rib 27 and the thickened portions 28 and 29 are located on the side surface of the rear blade group 11 of the shutter base plate 20, and are positioned outside the running area 32 of the main and auxiliary arms 11a and 11b, that is, with a margin in the thickness direction. Since the space is formed in a certain area (molded integrally with the shutter base plate 20), the strength of the shutter base plate 20 can be improved, but the thickness of the entire shutter can not be particularly increased.

33 is an aperture of the shutter base plate 20;
A chamfered portion 33a is formed on the edge of the aperture 33 to make the trailing blade group 11 run smoothly.

The feature of this embodiment is that the thickened portions 29, 30, 31 are provided to improve the strength of the shutter base plate 20.
However, the thickened parts 29, 30, and 31 are provided in positions that do not increase the thickness of the shutter as a whole, but in other words, the increased thickness parts 29, 30, and 31 are provided within the extra space in the thickness direction of the shutter base plate 20. That's true. This will be explained in detail using FIG. 2.

FIG. 2 shows a cross section of the caulking part for link connection between the main arm 11a of the rear blade group 11 and the divided blade 11d. A caulking dowel 11f is formed on the lower side). It is necessary to set at least the amount of protrusion of the caulking dowel 11f as a margin in the thickness direction on the surface of the shutter base plate 20, and in reality, it is common to provide a larger margin in the thickness direction in consideration of safety. It is. Therefore, the thickened portions 29, 30, and 31 in this embodiment protrude within the above-mentioned allowance in the thickness direction, and are outside the running area (relatively) of the main arm 11a and the auxiliary arm 11b of the rear blade group 11. Thick arm 11a, 11b and caulking dowel 1
By locating it outside the 1f travel area, the overall thickness of the shutter does not increase in any way.

In the embodiment, the rear blade group 11 is the one closest to the shutter base plate 20, but it goes without saying that the front blade group 10 may be used conversely.

(Effects of the Invention) As explained above, the present invention provides a camera shutter having a shutter base plate molded from synthetic resin, which simplifies the process and reduces costs.
In contrast to the swing area of the arm that runs the blade group that is closer in the thickness direction on the shutter base plate, the swing area of the arm that runs the blade group that is farther away in the thickness direction is thicker on the running surface side. Since the thickened portion is integrally molded during molding, the strength of the shutter can be improved without increasing the thickness of the entire shutter. In addition,
The swing area of the arm that runs the blade group is equipped with shafts that are subject to heavy loads nearby.
Improving the strength of this swing region has a great effect.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a camera shutter as an embodiment. FIG. 2 is an enlarged cross-sectional view taken along line A-A in FIG. 1. FIG. 3 is an exploded perspective view of a conventional camera shutter. 11... Rear blade group, 11a... Main arm, 11b...
Auxiliary arm, 20... Shutter base plate, 32... Running area of both arms, 29, 30, 31... Increased thickness portion.

Claims (1)

[Claims] 1. A first blade group that travels by the swinging of the first arm, a second blade group that travels by the swinging of the second arm, and a first blade group that is molded from synthetic resin. A shutter base plate for a camera having at least a shutter base plate, wherein a surface of the shutter base plate on which the plurality of blade groups run, and a blade group which is closer in the thickness direction among the plurality of blade groups. A shutter for a camera, characterized in that a thickened part is integrally molded so that the swinging area of the arm that runs the blade group farther away in the thickness direction is thicker than the swinging area of the arm that runs.